Merge tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block

[linux/fpc-iii.git] / drivers / staging / octeon-usb / octeon-hcd.c

// SPDX-License-Identifier: GPL-2.0
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2008 Cavium Networks
 *
 * Some parts of the code were originally released under BSD license:
 *
 * Copyright (c) 2003-2010 Cavium Networks (support@cavium.com). All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *
 *   * Neither the name of Cavium Networks nor the names of
 *     its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written
 *     permission.
 *
 * This Software, including technical data, may be subject to U.S. export
 * control laws, including the U.S. Export Administration Act and its associated
 * regulations, and may be subject to export or import regulations in other
 * countries.
 *
 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, THE SOFTWARE IS PROVIDED "AS IS"
 * AND WITH ALL FAULTS AND CAVIUM NETWORKS MAKES NO PROMISES, REPRESENTATIONS OR
 * WARRANTIES, EITHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE, WITH RESPECT TO
 * THE SOFTWARE, INCLUDING ITS CONDITION, ITS CONFORMITY TO ANY REPRESENTATION
 * OR DESCRIPTION, OR THE EXISTENCE OF ANY LATENT OR PATENT DEFECTS, AND CAVIUM
 * SPECIFICALLY DISCLAIMS ALL IMPLIED (IF ANY) WARRANTIES OF TITLE,
 * MERCHANTABILITY, NONINFRINGEMENT, FITNESS FOR A PARTICULAR PURPOSE, LACK OF
 * VIRUSES, ACCURACY OR COMPLETENESS, QUIET ENJOYMENT, QUIET POSSESSION OR
 * CORRESPONDENCE TO DESCRIPTION. THE ENTIRE RISK ARISING OUT OF USE OR
 * PERFORMANCE OF THE SOFTWARE LIES WITH YOU.
 */

#include <linux/usb.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/usb/hcd.h>
#include <linux/prefetch.h>
#include <linux/dma-mapping.h>
#include <linux/platform_device.h>

#include <asm/octeon/octeon.h>

#include "octeon-hcd.h"

/**
 * enum cvmx_usb_speed - the possible USB device speeds
 *
 * @CVMX_USB_SPEED_HIGH: Device is operation at 480Mbps
 * @CVMX_USB_SPEED_FULL: Device is operation at 12Mbps
 * @CVMX_USB_SPEED_LOW:  Device is operation at 1.5Mbps
 */
enum cvmx_usb_speed {
        CVMX_USB_SPEED_HIGH = 0,
        CVMX_USB_SPEED_FULL = 1,
        CVMX_USB_SPEED_LOW = 2,
};

/**
 * enum cvmx_usb_transfer - the possible USB transfer types
 *
 * @CVMX_USB_TRANSFER_CONTROL:     USB transfer type control for hub and status
 *                                 transfers
 * @CVMX_USB_TRANSFER_ISOCHRONOUS: USB transfer type isochronous for low
 *                                 priority periodic transfers
 * @CVMX_USB_TRANSFER_BULK:        USB transfer type bulk for large low priority
 *                                 transfers
 * @CVMX_USB_TRANSFER_INTERRUPT:   USB transfer type interrupt for high priority
 *                                 periodic transfers
 */
enum cvmx_usb_transfer {
        CVMX_USB_TRANSFER_CONTROL = 0,
        CVMX_USB_TRANSFER_ISOCHRONOUS = 1,
        CVMX_USB_TRANSFER_BULK = 2,
        CVMX_USB_TRANSFER_INTERRUPT = 3,
};

/**
 * enum cvmx_usb_direction - the transfer directions
 *
 * @CVMX_USB_DIRECTION_OUT: Data is transferring from Octeon to the device/host
 * @CVMX_USB_DIRECTION_IN:  Data is transferring from the device/host to Octeon
 */
enum cvmx_usb_direction {
        CVMX_USB_DIRECTION_OUT,
        CVMX_USB_DIRECTION_IN,
};

/**
 * enum cvmx_usb_status - possible callback function status codes
 *
 * @CVMX_USB_STATUS_OK:           The transaction / operation finished without
 *                                any errors
 * @CVMX_USB_STATUS_SHORT:        FIXME: This is currently not implemented
 * @CVMX_USB_STATUS_CANCEL:       The transaction was canceled while in flight
 *                                by a user call to cvmx_usb_cancel
 * @CVMX_USB_STATUS_ERROR:        The transaction aborted with an unexpected
 *                                error status
 * @CVMX_USB_STATUS_STALL:        The transaction received a USB STALL response
 *                                from the device
 * @CVMX_USB_STATUS_XACTERR:      The transaction failed with an error from the
 *                                device even after a number of retries
 * @CVMX_USB_STATUS_DATATGLERR:   The transaction failed with a data toggle
 *                                error even after a number of retries
 * @CVMX_USB_STATUS_BABBLEERR:    The transaction failed with a babble error
 * @CVMX_USB_STATUS_FRAMEERR:     The transaction failed with a frame error
 *                                even after a number of retries
 */
enum cvmx_usb_status {
        CVMX_USB_STATUS_OK,
        CVMX_USB_STATUS_SHORT,
        CVMX_USB_STATUS_CANCEL,
        CVMX_USB_STATUS_ERROR,
        CVMX_USB_STATUS_STALL,
        CVMX_USB_STATUS_XACTERR,
        CVMX_USB_STATUS_DATATGLERR,
        CVMX_USB_STATUS_BABBLEERR,
        CVMX_USB_STATUS_FRAMEERR,
};

/**
 * struct cvmx_usb_port_status - the USB port status information
 *
 * @port_enabled:       1 = Usb port is enabled, 0 = disabled
 * @port_over_current:  1 = Over current detected, 0 = Over current not
 *                      detected. Octeon doesn't support over current detection.
 * @port_powered:       1 = Port power is being supplied to the device, 0 =
 *                      power is off. Octeon doesn't support turning port power
 *                      off.
 * @port_speed:         Current port speed.
 * @connected:          1 = A device is connected to the port, 0 = No device is
 *                      connected.
 * @connect_change:     1 = Device connected state changed since the last set
 *                      status call.
 */
struct cvmx_usb_port_status {
        u32 reserved                    : 25;
        u32 port_enabled                : 1;
        u32 port_over_current           : 1;
        u32 port_powered                : 1;
        enum cvmx_usb_speed port_speed  : 2;
        u32 connected                   : 1;
        u32 connect_change              : 1;
};

/**
 * struct cvmx_usb_iso_packet - descriptor for Isochronous packets
 *
 * @offset:     This is the offset in bytes into the main buffer where this data
 *              is stored.
 * @length:     This is the length in bytes of the data.
 * @status:     This is the status of this individual packet transfer.
 */
struct cvmx_usb_iso_packet {
        int offset;
        int length;
        enum cvmx_usb_status status;
};

/**
 * enum cvmx_usb_initialize_flags - flags used by the initialization function
 *
 * @CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_XI:    The USB port uses a 12MHz crystal
 *                                            as clock source at USB_XO and
 *                                            USB_XI.
 * @CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_GND:   The USB port uses 12/24/48MHz 2.5V
 *                                            board clock source at USB_XO.
 *                                            USB_XI should be tied to GND.
 * @CVMX_USB_INITIALIZE_FLAGS_CLOCK_MHZ_MASK: Mask for clock speed field
 * @CVMX_USB_INITIALIZE_FLAGS_CLOCK_12MHZ:    Speed of reference clock or
 *                                            crystal
 * @CVMX_USB_INITIALIZE_FLAGS_CLOCK_24MHZ:    Speed of reference clock
 * @CVMX_USB_INITIALIZE_FLAGS_CLOCK_48MHZ:    Speed of reference clock
 * @CVMX_USB_INITIALIZE_FLAGS_NO_DMA:         Disable DMA and used polled IO for
 *                                            data transfer use for the USB
 */
enum cvmx_usb_initialize_flags {
        CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_XI           = 1 << 0,
        CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_GND          = 1 << 1,
        CVMX_USB_INITIALIZE_FLAGS_CLOCK_MHZ_MASK        = 3 << 3,
        CVMX_USB_INITIALIZE_FLAGS_CLOCK_12MHZ           = 1 << 3,
        CVMX_USB_INITIALIZE_FLAGS_CLOCK_24MHZ           = 2 << 3,
        CVMX_USB_INITIALIZE_FLAGS_CLOCK_48MHZ           = 3 << 3,
        /* Bits 3-4 used to encode the clock frequency */
        CVMX_USB_INITIALIZE_FLAGS_NO_DMA                = 1 << 5,
};

/**
 * enum cvmx_usb_pipe_flags - internal flags for a pipe.
 *
 * @CVMX_USB_PIPE_FLAGS_SCHEDULED: Used internally to determine if a pipe is
 *                                 actively using hardware.
 * @CVMX_USB_PIPE_FLAGS_NEED_PING: Used internally to determine if a high speed
 *                                 pipe is in the ping state.
 */
enum cvmx_usb_pipe_flags {
        CVMX_USB_PIPE_FLAGS_SCHEDULED   = 1 << 17,
        CVMX_USB_PIPE_FLAGS_NEED_PING   = 1 << 18,
};

/* Maximum number of times to retry failed transactions */
#define MAX_RETRIES             3

/* Maximum number of hardware channels supported by the USB block */
#define MAX_CHANNELS            8

/*
 * The low level hardware can transfer a maximum of this number of bytes in each
 * transfer. The field is 19 bits wide
 */
#define MAX_TRANSFER_BYTES      ((1 << 19) - 1)

/*
 * The low level hardware can transfer a maximum of this number of packets in
 * each transfer. The field is 10 bits wide
 */
#define MAX_TRANSFER_PACKETS    ((1 << 10) - 1)

/**
 * Logical transactions may take numerous low level
 * transactions, especially when splits are concerned. This
 * enum represents all of the possible stages a transaction can
 * be in. Note that split completes are always even. This is so
 * the NAK handler can backup to the previous low level
 * transaction with a simple clearing of bit 0.
 */
enum cvmx_usb_stage {
        CVMX_USB_STAGE_NON_CONTROL,
        CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE,
        CVMX_USB_STAGE_SETUP,
        CVMX_USB_STAGE_SETUP_SPLIT_COMPLETE,
        CVMX_USB_STAGE_DATA,
        CVMX_USB_STAGE_DATA_SPLIT_COMPLETE,
        CVMX_USB_STAGE_STATUS,
        CVMX_USB_STAGE_STATUS_SPLIT_COMPLETE,
};

/**
 * struct cvmx_usb_transaction - describes each pending USB transaction
 *                               regardless of type. These are linked together
 *                               to form a list of pending requests for a pipe.
 *
 * @node:               List node for transactions in the pipe.
 * @type:               Type of transaction, duplicated of the pipe.
 * @flags:              State flags for this transaction.
 * @buffer:             User's physical buffer address to read/write.
 * @buffer_length:      Size of the user's buffer in bytes.
 * @control_header:     For control transactions, physical address of the 8
 *                      byte standard header.
 * @iso_start_frame:    For ISO transactions, the starting frame number.
 * @iso_number_packets: For ISO transactions, the number of packets in the
 *                      request.
 * @iso_packets:        For ISO transactions, the sub packets in the request.
 * @actual_bytes:       Actual bytes transfer for this transaction.
 * @stage:              For control transactions, the current stage.
 * @urb:                URB.
 */
struct cvmx_usb_transaction {
        struct list_head node;
        enum cvmx_usb_transfer type;
        u64 buffer;
        int buffer_length;
        u64 control_header;
        int iso_start_frame;
        int iso_number_packets;
        struct cvmx_usb_iso_packet *iso_packets;
        int xfersize;
        int pktcnt;
        int retries;
        int actual_bytes;
        enum cvmx_usb_stage stage;
        struct urb *urb;
};

/**
 * struct cvmx_usb_pipe - a pipe represents a virtual connection between Octeon
 *                        and some USB device. It contains a list of pending
 *                        request to the device.
 *
 * @node:               List node for pipe list
 * @next:               Pipe after this one in the list
 * @transactions:       List of pending transactions
 * @interval:           For periodic pipes, the interval between packets in
 *                      frames
 * @next_tx_frame:      The next frame this pipe is allowed to transmit on
 * @flags:              State flags for this pipe
 * @device_speed:       Speed of device connected to this pipe
 * @transfer_type:      Type of transaction supported by this pipe
 * @transfer_dir:       IN or OUT. Ignored for Control
 * @multi_count:        Max packet in a row for the device
 * @max_packet:         The device's maximum packet size in bytes
 * @device_addr:        USB device address at other end of pipe
 * @endpoint_num:       USB endpoint number at other end of pipe
 * @hub_device_addr:    Hub address this device is connected to
 * @hub_port:           Hub port this device is connected to
 * @pid_toggle:         This toggles between 0/1 on every packet send to track
 *                      the data pid needed
 * @channel:            Hardware DMA channel for this pipe
 * @split_sc_frame:     The low order bits of the frame number the split
 *                      complete should be sent on
 */
struct cvmx_usb_pipe {
        struct list_head node;
        struct list_head transactions;
        u64 interval;
        u64 next_tx_frame;
        enum cvmx_usb_pipe_flags flags;
        enum cvmx_usb_speed device_speed;
        enum cvmx_usb_transfer transfer_type;
        enum cvmx_usb_direction transfer_dir;
        int multi_count;
        u16 max_packet;
        u8 device_addr;
        u8 endpoint_num;
        u8 hub_device_addr;
        u8 hub_port;
        u8 pid_toggle;
        u8 channel;
        s8 split_sc_frame;
};

struct cvmx_usb_tx_fifo {
        struct {
                int channel;
                int size;
                u64 address;
        } entry[MAX_CHANNELS + 1];
        int head;
        int tail;
};

/**
 * struct octeon_hcd - the state of the USB block
 *
 * lock:                   Serialization lock.
 * init_flags:             Flags passed to initialize.
 * index:                  Which USB block this is for.
 * idle_hardware_channels: Bit set for every idle hardware channel.
 * usbcx_hprt:             Stored port status so we don't need to read a CSR to
 *                         determine splits.
 * pipe_for_channel:       Map channels to pipes.
 * pipe:                   Storage for pipes.
 * indent:                 Used by debug output to indent functions.
 * port_status:            Last port status used for change notification.
 * idle_pipes:             List of open pipes that have no transactions.
 * active_pipes:           Active pipes indexed by transfer type.
 * frame_number:           Increments every SOF interrupt for time keeping.
 * active_split:           Points to the current active split, or NULL.
 */
struct octeon_hcd {
        spinlock_t lock; /* serialization lock */
        int init_flags;
        int index;
        int idle_hardware_channels;
        union cvmx_usbcx_hprt usbcx_hprt;
        struct cvmx_usb_pipe *pipe_for_channel[MAX_CHANNELS];
        int indent;
        struct cvmx_usb_port_status port_status;
        struct list_head idle_pipes;
        struct list_head active_pipes[4];
        u64 frame_number;
        struct cvmx_usb_transaction *active_split;
        struct cvmx_usb_tx_fifo periodic;
        struct cvmx_usb_tx_fifo nonperiodic;
};

/*
 * This macro logically sets a single field in a CSR. It does the sequence
 * read, modify, and write
 */
#define USB_SET_FIELD32(address, _union, field, value)          \
        do {                                                    \
                union _union c;                                 \
                                                                \
                c.u32 = cvmx_usb_read_csr32(usb, address);      \
                c.s.field = value;                              \
                cvmx_usb_write_csr32(usb, address, c.u32);      \
        } while (0)

/* Returns the IO address to push/pop stuff data from the FIFOs */
#define USB_FIFO_ADDRESS(channel, usb_index) \
        (CVMX_USBCX_GOTGCTL(usb_index) + ((channel) + 1) * 0x1000)

/**
 * struct octeon_temp_buffer - a bounce buffer for USB transfers
 * @orig_buffer: the original buffer passed by the USB stack
 * @data:        the newly allocated temporary buffer (excluding meta-data)
 *
 * Both the DMA engine and FIFO mode will always transfer full 32-bit words. If
 * the buffer is too short, we need to allocate a temporary one, and this struct
 * represents it.
 */
struct octeon_temp_buffer {
        void *orig_buffer;
        u8 data[];
};

static inline struct usb_hcd *octeon_to_hcd(struct octeon_hcd *p)
{
        return container_of((void *)p, struct usb_hcd, hcd_priv);
}

/**
 * octeon_alloc_temp_buffer - allocate a temporary buffer for USB transfer
 *                            (if needed)
 * @urb:        URB.
 * @mem_flags:  Memory allocation flags.
 *
 * This function allocates a temporary bounce buffer whenever it's needed
 * due to HW limitations.
 */
static int octeon_alloc_temp_buffer(struct urb *urb, gfp_t mem_flags)
{
        struct octeon_temp_buffer *temp;

        if (urb->num_sgs || urb->sg ||
            (urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) ||
            !(urb->transfer_buffer_length % sizeof(u32)))
                return 0;

        temp = kmalloc(ALIGN(urb->transfer_buffer_length, sizeof(u32)) +
                       sizeof(*temp), mem_flags);
        if (!temp)
                return -ENOMEM;

        temp->orig_buffer = urb->transfer_buffer;
        if (usb_urb_dir_out(urb))
                memcpy(temp->data, urb->transfer_buffer,
                       urb->transfer_buffer_length);
        urb->transfer_buffer = temp->data;
        urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;

        return 0;
}

/**
 * octeon_free_temp_buffer - free a temporary buffer used by USB transfers.
 * @urb: URB.
 *
 * Frees a buffer allocated by octeon_alloc_temp_buffer().
 */
static void octeon_free_temp_buffer(struct urb *urb)
{
        struct octeon_temp_buffer *temp;
        size_t length;

        if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
                return;

        temp = container_of(urb->transfer_buffer, struct octeon_temp_buffer,
                            data);
        if (usb_urb_dir_in(urb)) {
                if (usb_pipeisoc(urb->pipe))
                        length = urb->transfer_buffer_length;
                else
                        length = urb->actual_length;

                memcpy(temp->orig_buffer, urb->transfer_buffer, length);
        }
        urb->transfer_buffer = temp->orig_buffer;
        urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
        kfree(temp);
}

/**
 * octeon_map_urb_for_dma - Octeon-specific map_urb_for_dma().
 * @hcd:        USB HCD structure.
 * @urb:        URB.
 * @mem_flags:  Memory allocation flags.
 */
static int octeon_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
                                  gfp_t mem_flags)
{
        int ret;

        ret = octeon_alloc_temp_buffer(urb, mem_flags);
        if (ret)
                return ret;

        ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
        if (ret)
                octeon_free_temp_buffer(urb);

        return ret;
}

/**
 * octeon_unmap_urb_for_dma - Octeon-specific unmap_urb_for_dma()
 * @hcd:        USB HCD structure.
 * @urb:        URB.
 */
static void octeon_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
{
        usb_hcd_unmap_urb_for_dma(hcd, urb);
        octeon_free_temp_buffer(urb);
}

/**
 * Read a USB 32bit CSR. It performs the necessary address swizzle
 * for 32bit CSRs and logs the value in a readable format if
 * debugging is on.
 *
 * @usb:     USB block this access is for
 * @address: 64bit address to read
 *
 * Returns: Result of the read
 */
static inline u32 cvmx_usb_read_csr32(struct octeon_hcd *usb, u64 address)
{
        return cvmx_read64_uint32(address ^ 4);
}

/**
 * Write a USB 32bit CSR. It performs the necessary address
 * swizzle for 32bit CSRs and logs the value in a readable format
 * if debugging is on.
 *
 * @usb:     USB block this access is for
 * @address: 64bit address to write
 * @value:   Value to write
 */
static inline void cvmx_usb_write_csr32(struct octeon_hcd *usb,
                                        u64 address, u32 value)
{
        cvmx_write64_uint32(address ^ 4, value);
        cvmx_read64_uint64(CVMX_USBNX_DMA0_INB_CHN0(usb->index));
}

/**
 * Return non zero if this pipe connects to a non HIGH speed
 * device through a high speed hub.
 *
 * @usb:    USB block this access is for
 * @pipe:   Pipe to check
 *
 * Returns: Non zero if we need to do split transactions
 */
static inline int cvmx_usb_pipe_needs_split(struct octeon_hcd *usb,
                                            struct cvmx_usb_pipe *pipe)
{
        return pipe->device_speed != CVMX_USB_SPEED_HIGH &&
               usb->usbcx_hprt.s.prtspd == CVMX_USB_SPEED_HIGH;
}

/**
 * Trivial utility function to return the correct PID for a pipe
 *
 * @pipe:   pipe to check
 *
 * Returns: PID for pipe
 */
static inline int cvmx_usb_get_data_pid(struct cvmx_usb_pipe *pipe)
{
        if (pipe->pid_toggle)
                return 2; /* Data1 */
        return 0; /* Data0 */
}

/* Loops through register until txfflsh or rxfflsh become zero.*/
static int cvmx_wait_tx_rx(struct octeon_hcd *usb, int fflsh_type)
{
        int result;
        u64 address = CVMX_USBCX_GRSTCTL(usb->index);
        u64 done = cvmx_get_cycle() + 100 *
                   (u64)octeon_get_clock_rate / 1000000;
        union cvmx_usbcx_grstctl c;

        while (1) {
                c.u32 = cvmx_usb_read_csr32(usb, address);
                if (fflsh_type == 0 && c.s.txfflsh == 0) {
                        result = 0;
                        break;
                } else if (fflsh_type == 1 && c.s.rxfflsh == 0) {
                        result = 0;
                        break;
                } else if (cvmx_get_cycle() > done) {
                        result = -1;
                        break;
                }

                __delay(100);
        }
        return result;
}

static void cvmx_fifo_setup(struct octeon_hcd *usb)
{
        union cvmx_usbcx_ghwcfg3 usbcx_ghwcfg3;
        union cvmx_usbcx_gnptxfsiz npsiz;
        union cvmx_usbcx_hptxfsiz psiz;

        usbcx_ghwcfg3.u32 = cvmx_usb_read_csr32(usb,
                                                CVMX_USBCX_GHWCFG3(usb->index));

        /*
         * Program the USBC_GRXFSIZ register to select the size of the receive
         * FIFO (25%).
         */
        USB_SET_FIELD32(CVMX_USBCX_GRXFSIZ(usb->index), cvmx_usbcx_grxfsiz,
                        rxfdep, usbcx_ghwcfg3.s.dfifodepth / 4);

        /*
         * Program the USBC_GNPTXFSIZ register to select the size and the start
         * address of the non-periodic transmit FIFO for nonperiodic
         * transactions (50%).
         */
        npsiz.u32 = cvmx_usb_read_csr32(usb, CVMX_USBCX_GNPTXFSIZ(usb->index));
        npsiz.s.nptxfdep = usbcx_ghwcfg3.s.dfifodepth / 2;
        npsiz.s.nptxfstaddr = usbcx_ghwcfg3.s.dfifodepth / 4;
        cvmx_usb_write_csr32(usb, CVMX_USBCX_GNPTXFSIZ(usb->index), npsiz.u32);

        /*
         * Program the USBC_HPTXFSIZ register to select the size and start
         * address of the periodic transmit FIFO for periodic transactions
         * (25%).
         */
        psiz.u32 = cvmx_usb_read_csr32(usb, CVMX_USBCX_HPTXFSIZ(usb->index));
        psiz.s.ptxfsize = usbcx_ghwcfg3.s.dfifodepth / 4;
        psiz.s.ptxfstaddr = 3 * usbcx_ghwcfg3.s.dfifodepth / 4;
        cvmx_usb_write_csr32(usb, CVMX_USBCX_HPTXFSIZ(usb->index), psiz.u32);

        /* Flush all FIFOs */
        USB_SET_FIELD32(CVMX_USBCX_GRSTCTL(usb->index),
                        cvmx_usbcx_grstctl, txfnum, 0x10);
        USB_SET_FIELD32(CVMX_USBCX_GRSTCTL(usb->index),
                        cvmx_usbcx_grstctl, txfflsh, 1);
        cvmx_wait_tx_rx(usb, 0);
        USB_SET_FIELD32(CVMX_USBCX_GRSTCTL(usb->index),
                        cvmx_usbcx_grstctl, rxfflsh, 1);
        cvmx_wait_tx_rx(usb, 1);
}

/**
 * Shutdown a USB port after a call to cvmx_usb_initialize().
 * The port should be disabled with all pipes closed when this
 * function is called.
 *
 * @usb: USB device state populated by cvmx_usb_initialize().
 *
 * Returns: 0 or a negative error code.
 */
static int cvmx_usb_shutdown(struct octeon_hcd *usb)
{
        union cvmx_usbnx_clk_ctl usbn_clk_ctl;

        /* Make sure all pipes are closed */
        if (!list_empty(&usb->idle_pipes) ||
            !list_empty(&usb->active_pipes[CVMX_USB_TRANSFER_ISOCHRONOUS]) ||
            !list_empty(&usb->active_pipes[CVMX_USB_TRANSFER_INTERRUPT]) ||
            !list_empty(&usb->active_pipes[CVMX_USB_TRANSFER_CONTROL]) ||
            !list_empty(&usb->active_pipes[CVMX_USB_TRANSFER_BULK]))
                return -EBUSY;

        /* Disable the clocks and put them in power on reset */
        usbn_clk_ctl.u64 = cvmx_read64_uint64(CVMX_USBNX_CLK_CTL(usb->index));
        usbn_clk_ctl.s.enable = 1;
        usbn_clk_ctl.s.por = 1;
        usbn_clk_ctl.s.hclk_rst = 1;
        usbn_clk_ctl.s.prst = 0;
        usbn_clk_ctl.s.hrst = 0;
        cvmx_write64_uint64(CVMX_USBNX_CLK_CTL(usb->index), usbn_clk_ctl.u64);
        return 0;
}

/**
 * Initialize a USB port for use. This must be called before any
 * other access to the Octeon USB port is made. The port starts
 * off in the disabled state.
 *
 * @dev:         Pointer to struct device for logging purposes.
 * @usb:         Pointer to struct octeon_hcd.
 *
 * Returns: 0 or a negative error code.
 */
static int cvmx_usb_initialize(struct device *dev,
                               struct octeon_hcd *usb)
{
        int channel;
        int divisor;
        int retries = 0;
        union cvmx_usbcx_hcfg usbcx_hcfg;
        union cvmx_usbnx_clk_ctl usbn_clk_ctl;
        union cvmx_usbcx_gintsts usbc_gintsts;
        union cvmx_usbcx_gahbcfg usbcx_gahbcfg;
        union cvmx_usbcx_gintmsk usbcx_gintmsk;
        union cvmx_usbcx_gusbcfg usbcx_gusbcfg;
        union cvmx_usbnx_usbp_ctl_status usbn_usbp_ctl_status;

retry:
        /*
         * Power On Reset and PHY Initialization
         *
         * 1. Wait for DCOK to assert (nothing to do)
         *
         * 2a. Write USBN0/1_CLK_CTL[POR] = 1 and
         *     USBN0/1_CLK_CTL[HRST,PRST,HCLK_RST] = 0
         */
        usbn_clk_ctl.u64 = cvmx_read64_uint64(CVMX_USBNX_CLK_CTL(usb->index));
        usbn_clk_ctl.s.por = 1;
        usbn_clk_ctl.s.hrst = 0;
        usbn_clk_ctl.s.prst = 0;
        usbn_clk_ctl.s.hclk_rst = 0;
        usbn_clk_ctl.s.enable = 0;
        /*
         * 2b. Select the USB reference clock/crystal parameters by writing
         *     appropriate values to USBN0/1_CLK_CTL[P_C_SEL, P_RTYPE, P_COM_ON]
         */
        if (usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_GND) {
                /*
                 * The USB port uses 12/24/48MHz 2.5V board clock
                 * source at USB_XO. USB_XI should be tied to GND.
                 * Most Octeon evaluation boards require this setting
                 */
                if (OCTEON_IS_MODEL(OCTEON_CN3XXX) ||
                    OCTEON_IS_MODEL(OCTEON_CN56XX) ||
                    OCTEON_IS_MODEL(OCTEON_CN50XX))
                        /* From CN56XX,CN50XX,CN31XX,CN30XX manuals */
                        usbn_clk_ctl.s.p_rtype = 2; /* p_rclk=1 & p_xenbn=0 */
                else
                        /* From CN52XX manual */
                        usbn_clk_ctl.s.p_rtype = 1;

                switch (usb->init_flags &
                        CVMX_USB_INITIALIZE_FLAGS_CLOCK_MHZ_MASK) {
                case CVMX_USB_INITIALIZE_FLAGS_CLOCK_12MHZ:
                        usbn_clk_ctl.s.p_c_sel = 0;
                        break;
                case CVMX_USB_INITIALIZE_FLAGS_CLOCK_24MHZ:
                        usbn_clk_ctl.s.p_c_sel = 1;
                        break;
                case CVMX_USB_INITIALIZE_FLAGS_CLOCK_48MHZ:
                        usbn_clk_ctl.s.p_c_sel = 2;
                        break;
                }
        } else {
                /*
                 * The USB port uses a 12MHz crystal as clock source
                 * at USB_XO and USB_XI
                 */
                if (OCTEON_IS_MODEL(OCTEON_CN3XXX))
                        /* From CN31XX,CN30XX manual */
                        usbn_clk_ctl.s.p_rtype = 3; /* p_rclk=1 & p_xenbn=1 */
                else
                        /* From CN56XX,CN52XX,CN50XX manuals. */
                        usbn_clk_ctl.s.p_rtype = 0;

                usbn_clk_ctl.s.p_c_sel = 0;
        }
        /*
         * 2c. Select the HCLK via writing USBN0/1_CLK_CTL[DIVIDE, DIVIDE2] and
         *     setting USBN0/1_CLK_CTL[ENABLE] = 1. Divide the core clock down
         *     such that USB is as close as possible to 125Mhz
         */
        divisor = DIV_ROUND_UP(octeon_get_clock_rate(), 125000000);
        /* Lower than 4 doesn't seem to work properly */
        if (divisor < 4)
                divisor = 4;
        usbn_clk_ctl.s.divide = divisor;
        usbn_clk_ctl.s.divide2 = 0;
        cvmx_write64_uint64(CVMX_USBNX_CLK_CTL(usb->index), usbn_clk_ctl.u64);

        /* 2d. Write USBN0/1_CLK_CTL[HCLK_RST] = 1 */
        usbn_clk_ctl.s.hclk_rst = 1;
        cvmx_write64_uint64(CVMX_USBNX_CLK_CTL(usb->index), usbn_clk_ctl.u64);
        /* 2e.  Wait 64 core-clock cycles for HCLK to stabilize */
        __delay(64);
        /*
         * 3. Program the power-on reset field in the USBN clock-control
         *    register:
         *    USBN_CLK_CTL[POR] = 0
         */
        usbn_clk_ctl.s.por = 0;
        cvmx_write64_uint64(CVMX_USBNX_CLK_CTL(usb->index), usbn_clk_ctl.u64);
        /* 4. Wait 1 ms for PHY clock to start */
        mdelay(1);
        /*
         * 5. Program the Reset input from automatic test equipment field in the
         *    USBP control and status register:
         *    USBN_USBP_CTL_STATUS[ATE_RESET] = 1
         */
        usbn_usbp_ctl_status.u64 =
                cvmx_read64_uint64(CVMX_USBNX_USBP_CTL_STATUS(usb->index));
        usbn_usbp_ctl_status.s.ate_reset = 1;
        cvmx_write64_uint64(CVMX_USBNX_USBP_CTL_STATUS(usb->index),
                            usbn_usbp_ctl_status.u64);
        /* 6. Wait 10 cycles */
        __delay(10);
        /*
         * 7. Clear ATE_RESET field in the USBN clock-control register:
         *    USBN_USBP_CTL_STATUS[ATE_RESET] = 0
         */
        usbn_usbp_ctl_status.s.ate_reset = 0;
        cvmx_write64_uint64(CVMX_USBNX_USBP_CTL_STATUS(usb->index),
                            usbn_usbp_ctl_status.u64);
        /*
         * 8. Program the PHY reset field in the USBN clock-control register:
         *    USBN_CLK_CTL[PRST] = 1
         */
        usbn_clk_ctl.s.prst = 1;
        cvmx_write64_uint64(CVMX_USBNX_CLK_CTL(usb->index), usbn_clk_ctl.u64);
        /*
         * 9. Program the USBP control and status register to select host or
         *    device mode. USBN_USBP_CTL_STATUS[HST_MODE] = 0 for host, = 1 for
         *    device
         */
        usbn_usbp_ctl_status.s.hst_mode = 0;
        cvmx_write64_uint64(CVMX_USBNX_USBP_CTL_STATUS(usb->index),
                            usbn_usbp_ctl_status.u64);
        /* 10. Wait 1 us */
        udelay(1);
        /*
         * 11. Program the hreset_n field in the USBN clock-control register:
         *     USBN_CLK_CTL[HRST] = 1
         */
        usbn_clk_ctl.s.hrst = 1;
        cvmx_write64_uint64(CVMX_USBNX_CLK_CTL(usb->index), usbn_clk_ctl.u64);
        /* 12. Proceed to USB core initialization */
        usbn_clk_ctl.s.enable = 1;
        cvmx_write64_uint64(CVMX_USBNX_CLK_CTL(usb->index), usbn_clk_ctl.u64);
        udelay(1);

        /*
         * USB Core Initialization
         *
         * 1. Read USBC_GHWCFG1, USBC_GHWCFG2, USBC_GHWCFG3, USBC_GHWCFG4 to
         *    determine USB core configuration parameters.
         *
         *    Nothing needed
         *
         * 2. Program the following fields in the global AHB configuration
         *    register (USBC_GAHBCFG)
         *    DMA mode, USBC_GAHBCFG[DMAEn]: 1 = DMA mode, 0 = slave mode
         *    Burst length, USBC_GAHBCFG[HBSTLEN] = 0
         *    Nonperiodic TxFIFO empty level (slave mode only),
         *    USBC_GAHBCFG[NPTXFEMPLVL]
         *    Periodic TxFIFO empty level (slave mode only),
         *    USBC_GAHBCFG[PTXFEMPLVL]
         *    Global interrupt mask, USBC_GAHBCFG[GLBLINTRMSK] = 1
         */
        usbcx_gahbcfg.u32 = 0;
        usbcx_gahbcfg.s.dmaen = !(usb->init_flags &
                                  CVMX_USB_INITIALIZE_FLAGS_NO_DMA);
        usbcx_gahbcfg.s.hbstlen = 0;
        usbcx_gahbcfg.s.nptxfemplvl = 1;
        usbcx_gahbcfg.s.ptxfemplvl = 1;
        usbcx_gahbcfg.s.glblintrmsk = 1;
        cvmx_usb_write_csr32(usb, CVMX_USBCX_GAHBCFG(usb->index),
                             usbcx_gahbcfg.u32);

        /*
         * 3. Program the following fields in USBC_GUSBCFG register.
         *    HS/FS timeout calibration, USBC_GUSBCFG[TOUTCAL] = 0
         *    ULPI DDR select, USBC_GUSBCFG[DDRSEL] = 0
         *    USB turnaround time, USBC_GUSBCFG[USBTRDTIM] = 0x5
         *    PHY low-power clock select, USBC_GUSBCFG[PHYLPWRCLKSEL] = 0
         */
        usbcx_gusbcfg.u32 = cvmx_usb_read_csr32(usb,
                                                CVMX_USBCX_GUSBCFG(usb->index));
        usbcx_gusbcfg.s.toutcal = 0;
        usbcx_gusbcfg.s.ddrsel = 0;
        usbcx_gusbcfg.s.usbtrdtim = 0x5;
        usbcx_gusbcfg.s.phylpwrclksel = 0;
        cvmx_usb_write_csr32(usb, CVMX_USBCX_GUSBCFG(usb->index),
                             usbcx_gusbcfg.u32);

        /*
         * 4. The software must unmask the following bits in the USBC_GINTMSK
         *    register.
         *    OTG interrupt mask, USBC_GINTMSK[OTGINTMSK] = 1
         *    Mode mismatch interrupt mask, USBC_GINTMSK[MODEMISMSK] = 1
         */
        usbcx_gintmsk.u32 = cvmx_usb_read_csr32(usb,
                                                CVMX_USBCX_GINTMSK(usb->index));
        usbcx_gintmsk.s.otgintmsk = 1;
        usbcx_gintmsk.s.modemismsk = 1;
        usbcx_gintmsk.s.hchintmsk = 1;
        usbcx_gintmsk.s.sofmsk = 0;
        /* We need RX FIFO interrupts if we don't have DMA */
        if (usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_NO_DMA)
                usbcx_gintmsk.s.rxflvlmsk = 1;
        cvmx_usb_write_csr32(usb, CVMX_USBCX_GINTMSK(usb->index),
                             usbcx_gintmsk.u32);

        /*
         * Disable all channel interrupts. We'll enable them per channel later.
         */
        for (channel = 0; channel < 8; channel++)
                cvmx_usb_write_csr32(usb,
                                     CVMX_USBCX_HCINTMSKX(channel, usb->index),
                                     0);

        /*
         * Host Port Initialization
         *
         * 1. Program the host-port interrupt-mask field to unmask,
         *    USBC_GINTMSK[PRTINT] = 1
         */
        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index),
                        cvmx_usbcx_gintmsk, prtintmsk, 1);
        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index),
                        cvmx_usbcx_gintmsk, disconnintmsk, 1);

        /*
         * 2. Program the USBC_HCFG register to select full-speed host
         *    or high-speed host.
         */
        usbcx_hcfg.u32 = cvmx_usb_read_csr32(usb, CVMX_USBCX_HCFG(usb->index));
        usbcx_hcfg.s.fslssupp = 0;
        usbcx_hcfg.s.fslspclksel = 0;
        cvmx_usb_write_csr32(usb, CVMX_USBCX_HCFG(usb->index), usbcx_hcfg.u32);

        cvmx_fifo_setup(usb);

        /*
         * If the controller is getting port events right after the reset, it
         * means the initialization failed. Try resetting the controller again
         * in such case. This is seen to happen after cold boot on DSR-1000N.
         */
        usbc_gintsts.u32 = cvmx_usb_read_csr32(usb,
                                               CVMX_USBCX_GINTSTS(usb->index));
        cvmx_usb_write_csr32(usb, CVMX_USBCX_GINTSTS(usb->index),
                             usbc_gintsts.u32);
        dev_dbg(dev, "gintsts after reset: 0x%x\n", (int)usbc_gintsts.u32);
        if (!usbc_gintsts.s.disconnint && !usbc_gintsts.s.prtint)
                return 0;
        if (retries++ >= 5)
                return -EAGAIN;
        dev_info(dev, "controller reset failed (gintsts=0x%x) - retrying\n",
                 (int)usbc_gintsts.u32);
        msleep(50);
        cvmx_usb_shutdown(usb);
        msleep(50);
        goto retry;
}

/**
 * Reset a USB port. After this call succeeds, the USB port is
 * online and servicing requests.
 *
 * @usb: USB device state populated by cvmx_usb_initialize().
 */
static void cvmx_usb_reset_port(struct octeon_hcd *usb)
{
        usb->usbcx_hprt.u32 = cvmx_usb_read_csr32(usb,
                                                  CVMX_USBCX_HPRT(usb->index));

        /* Program the port reset bit to start the reset process */
        USB_SET_FIELD32(CVMX_USBCX_HPRT(usb->index), cvmx_usbcx_hprt,
                        prtrst, 1);

        /*
         * Wait at least 50ms (high speed), or 10ms (full speed) for the reset
         * process to complete.
         */
        mdelay(50);

        /* Program the port reset bit to 0, USBC_HPRT[PRTRST] = 0 */
        USB_SET_FIELD32(CVMX_USBCX_HPRT(usb->index), cvmx_usbcx_hprt,
                        prtrst, 0);

        /*
         * Read the port speed field to get the enumerated speed,
         * USBC_HPRT[PRTSPD].
         */
        usb->usbcx_hprt.u32 = cvmx_usb_read_csr32(usb,
                                                  CVMX_USBCX_HPRT(usb->index));
}

/**
 * Disable a USB port. After this call the USB port will not
 * generate data transfers and will not generate events.
 * Transactions in process will fail and call their
 * associated callbacks.
 *
 * @usb: USB device state populated by cvmx_usb_initialize().
 *
 * Returns: 0 or a negative error code.
 */
static int cvmx_usb_disable(struct octeon_hcd *usb)
{
        /* Disable the port */
        USB_SET_FIELD32(CVMX_USBCX_HPRT(usb->index), cvmx_usbcx_hprt,
                        prtena, 1);
        return 0;
}

/**
 * Get the current state of the USB port. Use this call to
 * determine if the usb port has anything connected, is enabled,
 * or has some sort of error condition. The return value of this
 * call has "changed" bits to signal of the value of some fields
 * have changed between calls.
 *
 * @usb: USB device state populated by cvmx_usb_initialize().
 *
 * Returns: Port status information
 */
static struct cvmx_usb_port_status cvmx_usb_get_status(struct octeon_hcd *usb)
{
        union cvmx_usbcx_hprt usbc_hprt;
        struct cvmx_usb_port_status result;

        memset(&result, 0, sizeof(result));

        usbc_hprt.u32 = cvmx_usb_read_csr32(usb, CVMX_USBCX_HPRT(usb->index));
        result.port_enabled = usbc_hprt.s.prtena;
        result.port_over_current = usbc_hprt.s.prtovrcurract;
        result.port_powered = usbc_hprt.s.prtpwr;
        result.port_speed = usbc_hprt.s.prtspd;
        result.connected = usbc_hprt.s.prtconnsts;
        result.connect_change =
                result.connected != usb->port_status.connected;

        return result;
}

/**
 * Open a virtual pipe between the host and a USB device. A pipe
 * must be opened before data can be transferred between a device
 * and Octeon.
 *
 * @usb:             USB device state populated by cvmx_usb_initialize().
 * @device_addr:
 *                   USB device address to open the pipe to
 *                   (0-127).
 * @endpoint_num:
 *                   USB endpoint number to open the pipe to
 *                   (0-15).
 * @device_speed:
 *                   The speed of the device the pipe is going
 *                   to. This must match the device's speed,
 *                   which may be different than the port speed.
 * @max_packet:      The maximum packet length the device can
 *                   transmit/receive (low speed=0-8, full
 *                   speed=0-1023, high speed=0-1024). This value
 *                   comes from the standard endpoint descriptor
 *                   field wMaxPacketSize bits <10:0>.
 * @transfer_type:
 *                   The type of transfer this pipe is for.
 * @transfer_dir:
 *                   The direction the pipe is in. This is not
 *                   used for control pipes.
 * @interval:        For ISOCHRONOUS and INTERRUPT transfers,
 *                   this is how often the transfer is scheduled
 *                   for. All other transfers should specify
 *                   zero. The units are in frames (8000/sec at
 *                   high speed, 1000/sec for full speed).
 * @multi_count:
 *                   For high speed devices, this is the maximum
 *                   allowed number of packet per microframe.
 *                   Specify zero for non high speed devices. This
 *                   value comes from the standard endpoint descriptor
 *                   field wMaxPacketSize bits <12:11>.
 * @hub_device_addr:
 *                   Hub device address this device is connected
 *                   to. Devices connected directly to Octeon
 *                   use zero. This is only used when the device
 *                   is full/low speed behind a high speed hub.
 *                   The address will be of the high speed hub,
 *                   not and full speed hubs after it.
 * @hub_port:        Which port on the hub the device is
 *                   connected. Use zero for devices connected
 *                   directly to Octeon. Like hub_device_addr,
 *                   this is only used for full/low speed
 *                   devices behind a high speed hub.
 *
 * Returns: A non-NULL value is a pipe. NULL means an error.
 */
static struct cvmx_usb_pipe *cvmx_usb_open_pipe(struct octeon_hcd *usb,
                                                int device_addr,
                                                int endpoint_num,
                                                enum cvmx_usb_speed
                                                        device_speed,
                                                int max_packet,
                                                enum cvmx_usb_transfer
                                                        transfer_type,
                                                enum cvmx_usb_direction
                                                        transfer_dir,
                                                int interval, int multi_count,
                                                int hub_device_addr,
                                                int hub_port)
{
        struct cvmx_usb_pipe *pipe;

        pipe = kzalloc(sizeof(*pipe), GFP_ATOMIC);
        if (!pipe)
                return NULL;
        if ((device_speed == CVMX_USB_SPEED_HIGH) &&
            (transfer_dir == CVMX_USB_DIRECTION_OUT) &&
            (transfer_type == CVMX_USB_TRANSFER_BULK))
                pipe->flags |= CVMX_USB_PIPE_FLAGS_NEED_PING;
        pipe->device_addr = device_addr;
        pipe->endpoint_num = endpoint_num;
        pipe->device_speed = device_speed;
        pipe->max_packet = max_packet;
        pipe->transfer_type = transfer_type;
        pipe->transfer_dir = transfer_dir;
        INIT_LIST_HEAD(&pipe->transactions);

        /*
         * All pipes use interval to rate limit NAK processing. Force an
         * interval if one wasn't supplied
         */
        if (!interval)
                interval = 1;
        if (cvmx_usb_pipe_needs_split(usb, pipe)) {
                pipe->interval = interval * 8;
                /* Force start splits to be schedule on uFrame 0 */
                pipe->next_tx_frame = ((usb->frame_number + 7) & ~7) +
                                        pipe->interval;
        } else {
                pipe->interval = interval;
                pipe->next_tx_frame = usb->frame_number + pipe->interval;
        }
        pipe->multi_count = multi_count;
        pipe->hub_device_addr = hub_device_addr;
        pipe->hub_port = hub_port;
        pipe->pid_toggle = 0;
        pipe->split_sc_frame = -1;
        list_add_tail(&pipe->node, &usb->idle_pipes);

        /*
         * We don't need to tell the hardware about this pipe yet since
         * it doesn't have any submitted requests
         */

        return pipe;
}

/**
 * Poll the RX FIFOs and remove data as needed. This function is only used
 * in non DMA mode. It is very important that this function be called quickly
 * enough to prevent FIFO overflow.
 *
 * @usb:        USB device state populated by cvmx_usb_initialize().
 */
static void cvmx_usb_poll_rx_fifo(struct octeon_hcd *usb)
{
        union cvmx_usbcx_grxstsph rx_status;
        int channel;
        int bytes;
        u64 address;
        u32 *ptr;

        rx_status.u32 = cvmx_usb_read_csr32(usb,
                                            CVMX_USBCX_GRXSTSPH(usb->index));
        /* Only read data if IN data is there */
        if (rx_status.s.pktsts != 2)
                return;
        /* Check if no data is available */
        if (!rx_status.s.bcnt)
                return;

        channel = rx_status.s.chnum;
        bytes = rx_status.s.bcnt;
        if (!bytes)
                return;

        /* Get where the DMA engine would have written this data */
        address = cvmx_read64_uint64(CVMX_USBNX_DMA0_INB_CHN0(usb->index) +
                                     channel * 8);

        ptr = cvmx_phys_to_ptr(address);
        cvmx_write64_uint64(CVMX_USBNX_DMA0_INB_CHN0(usb->index) + channel * 8,
                            address + bytes);

        /* Loop writing the FIFO data for this packet into memory */
        while (bytes > 0) {
                *ptr++ = cvmx_usb_read_csr32(usb,
                                        USB_FIFO_ADDRESS(channel, usb->index));
                bytes -= 4;
        }
        CVMX_SYNCW;
}

/**
 * Fill the TX hardware fifo with data out of the software
 * fifos
 *
 * @usb:            USB device state populated by cvmx_usb_initialize().
 * @fifo:           Software fifo to use
 * @available:      Amount of space in the hardware fifo
 *
 * Returns: Non zero if the hardware fifo was too small and needs
 *          to be serviced again.
 */
static int cvmx_usb_fill_tx_hw(struct octeon_hcd *usb,
                               struct cvmx_usb_tx_fifo *fifo, int available)
{
        /*
         * We're done either when there isn't anymore space or the software FIFO
         * is empty
         */
        while (available && (fifo->head != fifo->tail)) {
                int i = fifo->tail;
                const u32 *ptr = cvmx_phys_to_ptr(fifo->entry[i].address);
                u64 csr_address = USB_FIFO_ADDRESS(fifo->entry[i].channel,
                                                   usb->index) ^ 4;
                int words = available;

                /* Limit the amount of data to what the SW fifo has */
                if (fifo->entry[i].size <= available) {
                        words = fifo->entry[i].size;
                        fifo->tail++;
                        if (fifo->tail > MAX_CHANNELS)
                                fifo->tail = 0;
                }

                /* Update the next locations and counts */
                available -= words;
                fifo->entry[i].address += words * 4;
                fifo->entry[i].size -= words;

                /*
                 * Write the HW fifo data. The read every three writes is due
                 * to an errata on CN3XXX chips
                 */
                while (words > 3) {
                        cvmx_write64_uint32(csr_address, *ptr++);
                        cvmx_write64_uint32(csr_address, *ptr++);
                        cvmx_write64_uint32(csr_address, *ptr++);
                        cvmx_read64_uint64(CVMX_USBNX_DMA0_INB_CHN0(usb->index));
                        words -= 3;
                }
                cvmx_write64_uint32(csr_address, *ptr++);
                if (--words) {
                        cvmx_write64_uint32(csr_address, *ptr++);
                        if (--words)
                                cvmx_write64_uint32(csr_address, *ptr++);
                }
                cvmx_read64_uint64(CVMX_USBNX_DMA0_INB_CHN0(usb->index));
        }
        return fifo->head != fifo->tail;
}

/**
 * Check the hardware FIFOs and fill them as needed
 *
 * @usb:        USB device state populated by cvmx_usb_initialize().
 */
static void cvmx_usb_poll_tx_fifo(struct octeon_hcd *usb)
{
        if (usb->periodic.head != usb->periodic.tail) {
                union cvmx_usbcx_hptxsts tx_status;

                tx_status.u32 = cvmx_usb_read_csr32(usb,
                                        CVMX_USBCX_HPTXSTS(usb->index));
                if (cvmx_usb_fill_tx_hw(usb, &usb->periodic,
                                        tx_status.s.ptxfspcavail))
                        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index),
                                        cvmx_usbcx_gintmsk, ptxfempmsk, 1);
                else
                        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index),
                                        cvmx_usbcx_gintmsk, ptxfempmsk, 0);
        }

        if (usb->nonperiodic.head != usb->nonperiodic.tail) {
                union cvmx_usbcx_gnptxsts tx_status;

                tx_status.u32 = cvmx_usb_read_csr32(usb,
                                        CVMX_USBCX_GNPTXSTS(usb->index));
                if (cvmx_usb_fill_tx_hw(usb, &usb->nonperiodic,
                                        tx_status.s.nptxfspcavail))
                        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index),
                                        cvmx_usbcx_gintmsk, nptxfempmsk, 1);
                else
                        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index),
                                        cvmx_usbcx_gintmsk, nptxfempmsk, 0);
        }
}

/**
 * Fill the TX FIFO with an outgoing packet
 *
 * @usb:          USB device state populated by cvmx_usb_initialize().
 * @channel:      Channel number to get packet from
 */
static void cvmx_usb_fill_tx_fifo(struct octeon_hcd *usb, int channel)
{
        union cvmx_usbcx_hccharx hcchar;
        union cvmx_usbcx_hcspltx usbc_hcsplt;
        union cvmx_usbcx_hctsizx usbc_hctsiz;
        struct cvmx_usb_tx_fifo *fifo;

        /* We only need to fill data on outbound channels */
        hcchar.u32 = cvmx_usb_read_csr32(usb,
                        CVMX_USBCX_HCCHARX(channel, usb->index));
        if (hcchar.s.epdir != CVMX_USB_DIRECTION_OUT)
                return;

        /* OUT Splits only have data on the start and not the complete */
        usbc_hcsplt.u32 = cvmx_usb_read_csr32(usb,
                                CVMX_USBCX_HCSPLTX(channel, usb->index));
        if (usbc_hcsplt.s.spltena && usbc_hcsplt.s.compsplt)
                return;

        /*
         * Find out how many bytes we need to fill and convert it into 32bit
         * words.
         */
        usbc_hctsiz.u32 = cvmx_usb_read_csr32(usb,
                                CVMX_USBCX_HCTSIZX(channel, usb->index));
        if (!usbc_hctsiz.s.xfersize)
                return;

        if ((hcchar.s.eptype == CVMX_USB_TRANSFER_INTERRUPT) ||
            (hcchar.s.eptype == CVMX_USB_TRANSFER_ISOCHRONOUS))
                fifo = &usb->periodic;
        else
                fifo = &usb->nonperiodic;

        fifo->entry[fifo->head].channel = channel;
        fifo->entry[fifo->head].address =
                cvmx_read64_uint64(CVMX_USBNX_DMA0_OUTB_CHN0(usb->index) +
                                   channel * 8);
        fifo->entry[fifo->head].size = (usbc_hctsiz.s.xfersize + 3) >> 2;
        fifo->head++;
        if (fifo->head > MAX_CHANNELS)
                fifo->head = 0;

        cvmx_usb_poll_tx_fifo(usb);
}

/**
 * Perform channel specific setup for Control transactions. All
 * the generic stuff will already have been done in cvmx_usb_start_channel().
 *
 * @usb:          USB device state populated by cvmx_usb_initialize().
 * @channel:      Channel to setup
 * @pipe:         Pipe for control transaction
 */
static void cvmx_usb_start_channel_control(struct octeon_hcd *usb,
                                           int channel,
                                           struct cvmx_usb_pipe *pipe)
{
        struct usb_hcd *hcd = octeon_to_hcd(usb);
        struct device *dev = hcd->self.controller;
        struct cvmx_usb_transaction *transaction =
                list_first_entry(&pipe->transactions, typeof(*transaction),
                                 node);
        struct usb_ctrlrequest *header =
                cvmx_phys_to_ptr(transaction->control_header);
        int bytes_to_transfer = transaction->buffer_length -
                transaction->actual_bytes;
        int packets_to_transfer;
        union cvmx_usbcx_hctsizx usbc_hctsiz;

        usbc_hctsiz.u32 = cvmx_usb_read_csr32(usb,
                                CVMX_USBCX_HCTSIZX(channel, usb->index));

        switch (transaction->stage) {
        case CVMX_USB_STAGE_NON_CONTROL:
        case CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE:
                dev_err(dev, "%s: ERROR - Non control stage\n", __func__);
                break;
        case CVMX_USB_STAGE_SETUP:
                usbc_hctsiz.s.pid = 3; /* Setup */
                bytes_to_transfer = sizeof(*header);
                /* All Control operations start with a setup going OUT */
                USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index),
                                cvmx_usbcx_hccharx, epdir,
                                CVMX_USB_DIRECTION_OUT);
                /*
                 * Setup send the control header instead of the buffer data. The
                 * buffer data will be used in the next stage
                 */
                cvmx_write64_uint64(CVMX_USBNX_DMA0_OUTB_CHN0(usb->index) +
                                        channel * 8,
                                    transaction->control_header);
                break;
        case CVMX_USB_STAGE_SETUP_SPLIT_COMPLETE:
                usbc_hctsiz.s.pid = 3; /* Setup */
                bytes_to_transfer = 0;
                /* All Control operations start with a setup going OUT */
                USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index),
                                cvmx_usbcx_hccharx, epdir,
                                CVMX_USB_DIRECTION_OUT);

                USB_SET_FIELD32(CVMX_USBCX_HCSPLTX(channel, usb->index),
                                cvmx_usbcx_hcspltx, compsplt, 1);
                break;
        case CVMX_USB_STAGE_DATA:
                usbc_hctsiz.s.pid = cvmx_usb_get_data_pid(pipe);
                if (cvmx_usb_pipe_needs_split(usb, pipe)) {
                        if (header->bRequestType & USB_DIR_IN)
                                bytes_to_transfer = 0;
                        else if (bytes_to_transfer > pipe->max_packet)
                                bytes_to_transfer = pipe->max_packet;
                }
                USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index),
                                cvmx_usbcx_hccharx, epdir,
                                ((header->bRequestType & USB_DIR_IN) ?
                                        CVMX_USB_DIRECTION_IN :
                                        CVMX_USB_DIRECTION_OUT));
                break;
        case CVMX_USB_STAGE_DATA_SPLIT_COMPLETE:
                usbc_hctsiz.s.pid = cvmx_usb_get_data_pid(pipe);
                if (!(header->bRequestType & USB_DIR_IN))
                        bytes_to_transfer = 0;
                USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index),
                                cvmx_usbcx_hccharx, epdir,
                                ((header->bRequestType & USB_DIR_IN) ?
                                        CVMX_USB_DIRECTION_IN :
                                        CVMX_USB_DIRECTION_OUT));
                USB_SET_FIELD32(CVMX_USBCX_HCSPLTX(channel, usb->index),
                                cvmx_usbcx_hcspltx, compsplt, 1);
                break;
        case CVMX_USB_STAGE_STATUS:
                usbc_hctsiz.s.pid = cvmx_usb_get_data_pid(pipe);
                bytes_to_transfer = 0;
                USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index),
                                cvmx_usbcx_hccharx, epdir,
                                ((header->bRequestType & USB_DIR_IN) ?
                                        CVMX_USB_DIRECTION_OUT :
                                        CVMX_USB_DIRECTION_IN));
                break;
        case CVMX_USB_STAGE_STATUS_SPLIT_COMPLETE:
                usbc_hctsiz.s.pid = cvmx_usb_get_data_pid(pipe);
                bytes_to_transfer = 0;
                USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index),
                                cvmx_usbcx_hccharx, epdir,
                                ((header->bRequestType & USB_DIR_IN) ?
                                        CVMX_USB_DIRECTION_OUT :
                                        CVMX_USB_DIRECTION_IN));
                USB_SET_FIELD32(CVMX_USBCX_HCSPLTX(channel, usb->index),
                                cvmx_usbcx_hcspltx, compsplt, 1);
                break;
        }

        /*
         * Make sure the transfer never exceeds the byte limit of the hardware.
         * Further bytes will be sent as continued transactions
         */
        if (bytes_to_transfer > MAX_TRANSFER_BYTES) {
                /* Round MAX_TRANSFER_BYTES to a multiple of out packet size */
                bytes_to_transfer = MAX_TRANSFER_BYTES / pipe->max_packet;
                bytes_to_transfer *= pipe->max_packet;
        }

        /*
         * Calculate the number of packets to transfer. If the length is zero
         * we still need to transfer one packet
         */
        packets_to_transfer = DIV_ROUND_UP(bytes_to_transfer,
                                           pipe->max_packet);
        if (packets_to_transfer == 0) {
                packets_to_transfer = 1;
        } else if ((packets_to_transfer > 1) &&
                        (usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_NO_DMA)) {
                /*
                 * Limit to one packet when not using DMA. Channels must be
                 * restarted between every packet for IN transactions, so there
                 * is no reason to do multiple packets in a row
                 */
                packets_to_transfer = 1;
                bytes_to_transfer = packets_to_transfer * pipe->max_packet;
        } else if (packets_to_transfer > MAX_TRANSFER_PACKETS) {
                /*
                 * Limit the number of packet and data transferred to what the
                 * hardware can handle
                 */
                packets_to_transfer = MAX_TRANSFER_PACKETS;
                bytes_to_transfer = packets_to_transfer * pipe->max_packet;
        }

        usbc_hctsiz.s.xfersize = bytes_to_transfer;
        usbc_hctsiz.s.pktcnt = packets_to_transfer;

        cvmx_usb_write_csr32(usb, CVMX_USBCX_HCTSIZX(channel, usb->index),
                             usbc_hctsiz.u32);
}

/**
 * Start a channel to perform the pipe's head transaction
 *
 * @usb:          USB device state populated by cvmx_usb_initialize().
 * @channel:      Channel to setup
 * @pipe:         Pipe to start
 */
static void cvmx_usb_start_channel(struct octeon_hcd *usb, int channel,
                                   struct cvmx_usb_pipe *pipe)
{
        struct cvmx_usb_transaction *transaction =
                list_first_entry(&pipe->transactions, typeof(*transaction),
                                 node);

        /* Make sure all writes to the DMA region get flushed */
        CVMX_SYNCW;

        /* Attach the channel to the pipe */
        usb->pipe_for_channel[channel] = pipe;
        pipe->channel = channel;
        pipe->flags |= CVMX_USB_PIPE_FLAGS_SCHEDULED;

        /* Mark this channel as in use */
        usb->idle_hardware_channels &= ~(1 << channel);

        /* Enable the channel interrupt bits */
        {
                union cvmx_usbcx_hcintx usbc_hcint;
                union cvmx_usbcx_hcintmskx usbc_hcintmsk;
                union cvmx_usbcx_haintmsk usbc_haintmsk;

                /* Clear all channel status bits */
                usbc_hcint.u32 = cvmx_usb_read_csr32(usb,
                                        CVMX_USBCX_HCINTX(channel, usb->index));

                cvmx_usb_write_csr32(usb,
                                     CVMX_USBCX_HCINTX(channel, usb->index),
                                     usbc_hcint.u32);

                usbc_hcintmsk.u32 = 0;
                usbc_hcintmsk.s.chhltdmsk = 1;
                if (usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_NO_DMA) {
                        /*
                         * Channels need these extra interrupts when we aren't
                         * in DMA mode.
                         */
                        usbc_hcintmsk.s.datatglerrmsk = 1;
                        usbc_hcintmsk.s.frmovrunmsk = 1;
                        usbc_hcintmsk.s.bblerrmsk = 1;
                        usbc_hcintmsk.s.xacterrmsk = 1;
                        if (cvmx_usb_pipe_needs_split(usb, pipe)) {
                                /*
                                 * Splits don't generate xfercompl, so we need
                                 * ACK and NYET.
                                 */
                                usbc_hcintmsk.s.nyetmsk = 1;
                                usbc_hcintmsk.s.ackmsk = 1;
                        }
                        usbc_hcintmsk.s.nakmsk = 1;
                        usbc_hcintmsk.s.stallmsk = 1;
                        usbc_hcintmsk.s.xfercomplmsk = 1;
                }
                cvmx_usb_write_csr32(usb,
                                     CVMX_USBCX_HCINTMSKX(channel, usb->index),
                                     usbc_hcintmsk.u32);

                /* Enable the channel interrupt to propagate */
                usbc_haintmsk.u32 = cvmx_usb_read_csr32(usb,
                                        CVMX_USBCX_HAINTMSK(usb->index));
                usbc_haintmsk.s.haintmsk |= 1 << channel;
                cvmx_usb_write_csr32(usb, CVMX_USBCX_HAINTMSK(usb->index),
                                     usbc_haintmsk.u32);
        }

        /* Setup the location the DMA engine uses. */
        {
                u64 reg;
                u64 dma_address = transaction->buffer +
                                  transaction->actual_bytes;

                if (transaction->type == CVMX_USB_TRANSFER_ISOCHRONOUS)
                        dma_address = transaction->buffer +
                                        transaction->iso_packets[0].offset +
                                        transaction->actual_bytes;

                if (pipe->transfer_dir == CVMX_USB_DIRECTION_OUT)
                        reg = CVMX_USBNX_DMA0_OUTB_CHN0(usb->index);
                else
                        reg = CVMX_USBNX_DMA0_INB_CHN0(usb->index);
                cvmx_write64_uint64(reg + channel * 8, dma_address);
        }

        /* Setup both the size of the transfer and the SPLIT characteristics */
        {
                union cvmx_usbcx_hcspltx usbc_hcsplt = {.u32 = 0};
                union cvmx_usbcx_hctsizx usbc_hctsiz = {.u32 = 0};
                int packets_to_transfer;
                int bytes_to_transfer = transaction->buffer_length -
                        transaction->actual_bytes;

                /*
                 * ISOCHRONOUS transactions store each individual transfer size
                 * in the packet structure, not the global buffer_length
                 */
                if (transaction->type == CVMX_USB_TRANSFER_ISOCHRONOUS)
                        bytes_to_transfer =
                                transaction->iso_packets[0].length -
                                transaction->actual_bytes;

                /*
                 * We need to do split transactions when we are talking to non
                 * high speed devices that are behind a high speed hub
                 */
                if (cvmx_usb_pipe_needs_split(usb, pipe)) {
                        /*
                         * On the start split phase (stage is even) record the
                         * frame number we will need to send the split complete.
                         * We only store the lower two bits since the time ahead
                         * can only be two frames
                         */
                        if ((transaction->stage & 1) == 0) {
                                if (transaction->type == CVMX_USB_TRANSFER_BULK)
                                        pipe->split_sc_frame =
                                                (usb->frame_number + 1) & 0x7f;
                                else
                                        pipe->split_sc_frame =
                                                (usb->frame_number + 2) & 0x7f;
                        } else {
                                pipe->split_sc_frame = -1;
                        }

                        usbc_hcsplt.s.spltena = 1;
                        usbc_hcsplt.s.hubaddr = pipe->hub_device_addr;
                        usbc_hcsplt.s.prtaddr = pipe->hub_port;
                        usbc_hcsplt.s.compsplt = (transaction->stage ==
                                CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE);

                        /*
                         * SPLIT transactions can only ever transmit one data
                         * packet so limit the transfer size to the max packet
                         * size
                         */
                        if (bytes_to_transfer > pipe->max_packet)
                                bytes_to_transfer = pipe->max_packet;

                        /*
                         * ISOCHRONOUS OUT splits are unique in that they limit
                         * data transfers to 188 byte chunks representing the
                         * begin/middle/end of the data or all
                         */
                        if (!usbc_hcsplt.s.compsplt &&
                            (pipe->transfer_dir == CVMX_USB_DIRECTION_OUT) &&
                            (pipe->transfer_type ==
                             CVMX_USB_TRANSFER_ISOCHRONOUS)) {
                                /*
                                 * Clear the split complete frame number as
                                 * there isn't going to be a split complete
                                 */
                                pipe->split_sc_frame = -1;
                                /*
                                 * See if we've started this transfer and sent
                                 * data
                                 */
                                if (transaction->actual_bytes == 0) {
                                        /*
                                         * Nothing sent yet, this is either a
                                         * begin or the entire payload
                                         */
                                        if (bytes_to_transfer <= 188)
                                                /* Entire payload in one go */
                                                usbc_hcsplt.s.xactpos = 3;
                                        else
                                                /* First part of payload */
                                                usbc_hcsplt.s.xactpos = 2;
                                } else {
                                        /*
                                         * Continuing the previous data, we must
                                         * either be in the middle or at the end
                                         */
                                        if (bytes_to_transfer <= 188)
                                                /* End of payload */
                                                usbc_hcsplt.s.xactpos = 1;
                                        else
                                                /* Middle of payload */
                                                usbc_hcsplt.s.xactpos = 0;
                                }
                                /*
                                 * Again, the transfer size is limited to 188
                                 * bytes
                                 */
                                if (bytes_to_transfer > 188)
                                        bytes_to_transfer = 188;
                        }
                }

                /*
                 * Make sure the transfer never exceeds the byte limit of the
                 * hardware. Further bytes will be sent as continued
                 * transactions
                 */
                if (bytes_to_transfer > MAX_TRANSFER_BYTES) {
                        /*
                         * Round MAX_TRANSFER_BYTES to a multiple of out packet
                         * size
                         */
                        bytes_to_transfer = MAX_TRANSFER_BYTES /
                                pipe->max_packet;
                        bytes_to_transfer *= pipe->max_packet;
                }

                /*
                 * Calculate the number of packets to transfer. If the length is
                 * zero we still need to transfer one packet
                 */
                packets_to_transfer =
                        DIV_ROUND_UP(bytes_to_transfer, pipe->max_packet);
                if (packets_to_transfer == 0) {
                        packets_to_transfer = 1;
                } else if ((packets_to_transfer > 1) &&
                           (usb->init_flags &
                            CVMX_USB_INITIALIZE_FLAGS_NO_DMA)) {
                        /*
                         * Limit to one packet when not using DMA. Channels must
                         * be restarted between every packet for IN
                         * transactions, so there is no reason to do multiple
                         * packets in a row
                         */
                        packets_to_transfer = 1;
                        bytes_to_transfer = packets_to_transfer *
                                pipe->max_packet;
                } else if (packets_to_transfer > MAX_TRANSFER_PACKETS) {
                        /*
                         * Limit the number of packet and data transferred to
                         * what the hardware can handle
                         */
                        packets_to_transfer = MAX_TRANSFER_PACKETS;
                        bytes_to_transfer = packets_to_transfer *
                                pipe->max_packet;
                }

                usbc_hctsiz.s.xfersize = bytes_to_transfer;
                usbc_hctsiz.s.pktcnt = packets_to_transfer;

                /* Update the DATA0/DATA1 toggle */
                usbc_hctsiz.s.pid = cvmx_usb_get_data_pid(pipe);
                /*
                 * High speed pipes may need a hardware ping before they start
                 */
                if (pipe->flags & CVMX_USB_PIPE_FLAGS_NEED_PING)
                        usbc_hctsiz.s.dopng = 1;

                cvmx_usb_write_csr32(usb,
                                     CVMX_USBCX_HCSPLTX(channel, usb->index),
                                     usbc_hcsplt.u32);
                cvmx_usb_write_csr32(usb,
                                     CVMX_USBCX_HCTSIZX(channel, usb->index),
                                     usbc_hctsiz.u32);
        }

        /* Setup the Host Channel Characteristics Register */
        {
                union cvmx_usbcx_hccharx usbc_hcchar = {.u32 = 0};

                /*
                 * Set the startframe odd/even properly. This is only used for
                 * periodic
                 */
                usbc_hcchar.s.oddfrm = usb->frame_number & 1;

                /*
                 * Set the number of back to back packets allowed by this
                 * endpoint. Split transactions interpret "ec" as the number of
                 * immediate retries of failure. These retries happen too
                 * quickly, so we disable these entirely for splits
                 */
                if (cvmx_usb_pipe_needs_split(usb, pipe))
                        usbc_hcchar.s.ec = 1;
                else if (pipe->multi_count < 1)
                        usbc_hcchar.s.ec = 1;
                else if (pipe->multi_count > 3)
                        usbc_hcchar.s.ec = 3;
                else
                        usbc_hcchar.s.ec = pipe->multi_count;

                /* Set the rest of the endpoint specific settings */
                usbc_hcchar.s.devaddr = pipe->device_addr;
                usbc_hcchar.s.eptype = transaction->type;
                usbc_hcchar.s.lspddev =
                        (pipe->device_speed == CVMX_USB_SPEED_LOW);
                usbc_hcchar.s.epdir = pipe->transfer_dir;
                usbc_hcchar.s.epnum = pipe->endpoint_num;
                usbc_hcchar.s.mps = pipe->max_packet;
                cvmx_usb_write_csr32(usb,
                                     CVMX_USBCX_HCCHARX(channel, usb->index),
                                     usbc_hcchar.u32);
        }

        /* Do transaction type specific fixups as needed */
        switch (transaction->type) {
        case CVMX_USB_TRANSFER_CONTROL:
                cvmx_usb_start_channel_control(usb, channel, pipe);
                break;
        case CVMX_USB_TRANSFER_BULK:
        case CVMX_USB_TRANSFER_INTERRUPT:
                break;
        case CVMX_USB_TRANSFER_ISOCHRONOUS:
                if (!cvmx_usb_pipe_needs_split(usb, pipe)) {
                        /*
                         * ISO transactions require different PIDs depending on
                         * direction and how many packets are needed
                         */
                        if (pipe->transfer_dir == CVMX_USB_DIRECTION_OUT) {
                                if (pipe->multi_count < 2) /* Need DATA0 */
                                        USB_SET_FIELD32(
                                                CVMX_USBCX_HCTSIZX(channel,
                                                                   usb->index),
                                                cvmx_usbcx_hctsizx, pid, 0);
                                else /* Need MDATA */
                                        USB_SET_FIELD32(
                                                CVMX_USBCX_HCTSIZX(channel,
                                                                   usb->index),
                                                cvmx_usbcx_hctsizx, pid, 3);
                        }
                }
                break;
        }
        {
                union cvmx_usbcx_hctsizx usbc_hctsiz = { .u32 =
                        cvmx_usb_read_csr32(usb,
                                            CVMX_USBCX_HCTSIZX(channel,
                                                               usb->index))
                };
                transaction->xfersize = usbc_hctsiz.s.xfersize;
                transaction->pktcnt = usbc_hctsiz.s.pktcnt;
        }
        /* Remember when we start a split transaction */
        if (cvmx_usb_pipe_needs_split(usb, pipe))
                usb->active_split = transaction;
        USB_SET_FIELD32(CVMX_USBCX_HCCHARX(channel, usb->index),
                        cvmx_usbcx_hccharx, chena, 1);
        if (usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_NO_DMA)
                cvmx_usb_fill_tx_fifo(usb, channel);
}

/**
 * Find a pipe that is ready to be scheduled to hardware.
 * @usb:         USB device state populated by cvmx_usb_initialize().
 * @xfer_type:   Transfer type
 *
 * Returns: Pipe or NULL if none are ready
 */
static struct cvmx_usb_pipe *cvmx_usb_find_ready_pipe(struct octeon_hcd *usb,
                enum cvmx_usb_transfer xfer_type)
{
        struct list_head *list = usb->active_pipes + xfer_type;
        u64 current_frame = usb->frame_number;
        struct cvmx_usb_pipe *pipe;

        list_for_each_entry(pipe, list, node) {
                struct cvmx_usb_transaction *t =
                        list_first_entry(&pipe->transactions, typeof(*t),
                                         node);
                if (!(pipe->flags & CVMX_USB_PIPE_FLAGS_SCHEDULED) && t &&
                    (pipe->next_tx_frame <= current_frame) &&
                    ((pipe->split_sc_frame == -1) ||
                     ((((int)current_frame - pipe->split_sc_frame) & 0x7f) <
                      0x40)) &&
                    (!usb->active_split || (usb->active_split == t))) {
                        prefetch(t);
                        return pipe;
                }
        }
        return NULL;
}

static struct cvmx_usb_pipe *cvmx_usb_next_pipe(struct octeon_hcd *usb,
                                                int is_sof)
{
        struct cvmx_usb_pipe *pipe;

        /* Find a pipe needing service. */
        if (is_sof) {
                /*
                 * Only process periodic pipes on SOF interrupts. This way we
                 * are sure that the periodic data is sent in the beginning of
                 * the frame.
                 */
                pipe = cvmx_usb_find_ready_pipe(usb,
                                                CVMX_USB_TRANSFER_ISOCHRONOUS);
                if (pipe)
                        return pipe;
                pipe = cvmx_usb_find_ready_pipe(usb,
                                                CVMX_USB_TRANSFER_INTERRUPT);
                if (pipe)
                        return pipe;
        }
        pipe = cvmx_usb_find_ready_pipe(usb, CVMX_USB_TRANSFER_CONTROL);
        if (pipe)
                return pipe;
        return cvmx_usb_find_ready_pipe(usb, CVMX_USB_TRANSFER_BULK);
}

/**
 * Called whenever a pipe might need to be scheduled to the
 * hardware.
 *
 * @usb:         USB device state populated by cvmx_usb_initialize().
 * @is_sof:      True if this schedule was called on a SOF interrupt.
 */
static void cvmx_usb_schedule(struct octeon_hcd *usb, int is_sof)
{
        int channel;
        struct cvmx_usb_pipe *pipe;
        int need_sof;
        enum cvmx_usb_transfer ttype;

        if (usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_NO_DMA) {
                /*
                 * Without DMA we need to be careful to not schedule something
                 * at the end of a frame and cause an overrun.
                 */
                union cvmx_usbcx_hfnum hfnum = {
                        .u32 = cvmx_usb_read_csr32(usb,
                                                CVMX_USBCX_HFNUM(usb->index))
                };

                union cvmx_usbcx_hfir hfir = {
                        .u32 = cvmx_usb_read_csr32(usb,
                                                CVMX_USBCX_HFIR(usb->index))
                };

                if (hfnum.s.frrem < hfir.s.frint / 4)
                        goto done;
        }

        while (usb->idle_hardware_channels) {
                /* Find an idle channel */
                channel = __fls(usb->idle_hardware_channels);
                if (unlikely(channel > 7))
                        break;

                pipe = cvmx_usb_next_pipe(usb, is_sof);
                if (!pipe)
                        break;

                cvmx_usb_start_channel(usb, channel, pipe);
        }

done:
        /*
         * Only enable SOF interrupts when we have transactions pending in the
         * future that might need to be scheduled
         */
        need_sof = 0;
        for (ttype = CVMX_USB_TRANSFER_CONTROL;
             ttype <= CVMX_USB_TRANSFER_INTERRUPT; ttype++) {
                list_for_each_entry(pipe, &usb->active_pipes[ttype], node) {
                        if (pipe->next_tx_frame > usb->frame_number) {
                                need_sof = 1;
                                break;
                        }
                }
        }
        USB_SET_FIELD32(CVMX_USBCX_GINTMSK(usb->index),
                        cvmx_usbcx_gintmsk, sofmsk, need_sof);
}

static void octeon_usb_urb_complete_callback(struct octeon_hcd *usb,
                                             enum cvmx_usb_status status,
                                             struct cvmx_usb_pipe *pipe,
                                             struct cvmx_usb_transaction
                                                *transaction,
                                             int bytes_transferred,
                                             struct urb *urb)
{
        struct usb_hcd *hcd = octeon_to_hcd(usb);
        struct device *dev = hcd->self.controller;

        if (likely(status == CVMX_USB_STATUS_OK))
                urb->actual_length = bytes_transferred;
        else
                urb->actual_length = 0;

        urb->hcpriv = NULL;

        /* For Isochronous transactions we need to update the URB packet status
         * list from data in our private copy
         */
        if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
                int i;
                /*
                 * The pointer to the private list is stored in the setup_packet
                 * field.
                 */
                struct cvmx_usb_iso_packet *iso_packet =
                        (struct cvmx_usb_iso_packet *)urb->setup_packet;
                /* Recalculate the transfer size by adding up each packet */
                urb->actual_length = 0;
                for (i = 0; i < urb->number_of_packets; i++) {
                        if (iso_packet[i].status == CVMX_USB_STATUS_OK) {
                                urb->iso_frame_desc[i].status = 0;
                                urb->iso_frame_desc[i].actual_length =
                                        iso_packet[i].length;
                                urb->actual_length +=
                                        urb->iso_frame_desc[i].actual_length;
                        } else {
                                dev_dbg(dev, "ISOCHRONOUS packet=%d of %d status=%d pipe=%p transaction=%p size=%d\n",
                                        i, urb->number_of_packets,
                                        iso_packet[i].status, pipe,
                                        transaction, iso_packet[i].length);
                                urb->iso_frame_desc[i].status = -EREMOTEIO;
                        }
                }
                /* Free the private list now that we don't need it anymore */
                kfree(iso_packet);
                urb->setup_packet = NULL;
        }

        switch (status) {
        case CVMX_USB_STATUS_OK:
                urb->status = 0;
                break;
        case CVMX_USB_STATUS_CANCEL:
                if (urb->status == 0)
                        urb->status = -ENOENT;
                break;
        case CVMX_USB_STATUS_STALL:
                dev_dbg(dev, "status=stall pipe=%p transaction=%p size=%d\n",
                        pipe, transaction, bytes_transferred);
                urb->status = -EPIPE;
                break;
        case CVMX_USB_STATUS_BABBLEERR:
                dev_dbg(dev, "status=babble pipe=%p transaction=%p size=%d\n",
                        pipe, transaction, bytes_transferred);
                urb->status = -EPIPE;
                break;
        case CVMX_USB_STATUS_SHORT:
                dev_dbg(dev, "status=short pipe=%p transaction=%p size=%d\n",
                        pipe, transaction, bytes_transferred);
                urb->status = -EREMOTEIO;
                break;
        case CVMX_USB_STATUS_ERROR:
        case CVMX_USB_STATUS_XACTERR:
        case CVMX_USB_STATUS_DATATGLERR:
        case CVMX_USB_STATUS_FRAMEERR:
                dev_dbg(dev, "status=%d pipe=%p transaction=%p size=%d\n",
                        status, pipe, transaction, bytes_transferred);
                urb->status = -EPROTO;
                break;
        }
        usb_hcd_unlink_urb_from_ep(octeon_to_hcd(usb), urb);
        spin_unlock(&usb->lock);
        usb_hcd_giveback_urb(octeon_to_hcd(usb), urb, urb->status);
        spin_lock(&usb->lock);
}

/**
 * Signal the completion of a transaction and free it. The
 * transaction will be removed from the pipe transaction list.
 *
 * @usb:         USB device state populated by cvmx_usb_initialize().
 * @pipe:        Pipe the transaction is on
 * @transaction:
 *               Transaction that completed
 * @complete_code:
 *               Completion code
 */
static void cvmx_usb_complete(struct octeon_hcd *usb,
                              struct cvmx_usb_pipe *pipe,
                              struct cvmx_usb_transaction *transaction,
                              enum cvmx_usb_status complete_code)
{
        /* If this was a split then clear our split in progress marker */
        if (usb->active_split == transaction)
                usb->active_split = NULL;

        /*
         * Isochronous transactions need extra processing as they might not be
         * done after a single data transfer
         */
        if (unlikely(transaction->type == CVMX_USB_TRANSFER_ISOCHRONOUS)) {
                /* Update the number of bytes transferred in this ISO packet */
                transaction->iso_packets[0].length = transaction->actual_bytes;
                transaction->iso_packets[0].status = complete_code;

                /*
                 * If there are more ISOs pending and we succeeded, schedule the
                 * next one
                 */
                if ((transaction->iso_number_packets > 1) &&
                    (complete_code == CVMX_USB_STATUS_OK)) {
                        /* No bytes transferred for this packet as of yet */
                        transaction->actual_bytes = 0;
                        /* One less ISO waiting to transfer */
                        transaction->iso_number_packets--;
                        /* Increment to the next location in our packet array */
                        transaction->iso_packets++;
                        transaction->stage = CVMX_USB_STAGE_NON_CONTROL;
                        return;
                }
        }

        /* Remove the transaction from the pipe list */
        list_del(&transaction->node);
        if (list_empty(&pipe->transactions))
                list_move_tail(&pipe->node, &usb->idle_pipes);
        octeon_usb_urb_complete_callback(usb, complete_code, pipe,
                                         transaction,
                                         transaction->actual_bytes,
                                         transaction->urb);
        kfree(transaction);
}

/**
 * Submit a usb transaction to a pipe. Called for all types
 * of transactions.
 *
 * @usb:
 * @pipe:           Which pipe to submit to.
 * @type:           Transaction type
 * @buffer:         User buffer for the transaction
 * @buffer_length:
 *                  User buffer's length in bytes
 * @control_header:
 *                  For control transactions, the 8 byte standard header
 * @iso_start_frame:
 *                  For ISO transactions, the start frame
 * @iso_number_packets:
 *                  For ISO, the number of packet in the transaction.
 * @iso_packets:
 *                  A description of each ISO packet
 * @urb:            URB for the callback
 *
 * Returns: Transaction or NULL on failure.
 */
static struct cvmx_usb_transaction *cvmx_usb_submit_transaction(
                                struct octeon_hcd *usb,
                                struct cvmx_usb_pipe *pipe,
                                enum cvmx_usb_transfer type,
                                u64 buffer,
                                int buffer_length,
                                u64 control_header,
                                int iso_start_frame,
                                int iso_number_packets,
                                struct cvmx_usb_iso_packet *iso_packets,
                                struct urb *urb)
{
        struct cvmx_usb_transaction *transaction;

        if (unlikely(pipe->transfer_type != type))
                return NULL;

        transaction = kzalloc(sizeof(*transaction), GFP_ATOMIC);
        if (unlikely(!transaction))
                return NULL;

        transaction->type = type;
        transaction->buffer = buffer;
        transaction->buffer_length = buffer_length;
        transaction->control_header = control_header;
        /* FIXME: This is not used, implement it. */
        transaction->iso_start_frame = iso_start_frame;
        transaction->iso_number_packets = iso_number_packets;
        transaction->iso_packets = iso_packets;
        transaction->urb = urb;
        if (transaction->type == CVMX_USB_TRANSFER_CONTROL)
                transaction->stage = CVMX_USB_STAGE_SETUP;
        else
                transaction->stage = CVMX_USB_STAGE_NON_CONTROL;

        if (!list_empty(&pipe->transactions)) {
                list_add_tail(&transaction->node, &pipe->transactions);
        } else {
                list_add_tail(&transaction->node, &pipe->transactions);
                list_move_tail(&pipe->node,
                               &usb->active_pipes[pipe->transfer_type]);

                /*
                 * We may need to schedule the pipe if this was the head of the
                 * pipe.
                 */
                cvmx_usb_schedule(usb, 0);
        }

        return transaction;
}

/**
 * Call to submit a USB Bulk transfer to a pipe.
 *
 * @usb:            USB device state populated by cvmx_usb_initialize().
 * @pipe:           Handle to the pipe for the transfer.
 * @urb:            URB.
 *
 * Returns: A submitted transaction or NULL on failure.
 */
static struct cvmx_usb_transaction *cvmx_usb_submit_bulk(
                                                struct octeon_hcd *usb,
                                                struct cvmx_usb_pipe *pipe,
                                                struct urb *urb)
{
        return cvmx_usb_submit_transaction(usb, pipe, CVMX_USB_TRANSFER_BULK,
                                           urb->transfer_dma,
                                           urb->transfer_buffer_length,
                                           0, /* control_header */
                                           0, /* iso_start_frame */
                                           0, /* iso_number_packets */
                                           NULL, /* iso_packets */
                                           urb);
}

/**
 * Call to submit a USB Interrupt transfer to a pipe.
 *
 * @usb:            USB device state populated by cvmx_usb_initialize().
 * @pipe:           Handle to the pipe for the transfer.
 * @urb:            URB returned when the callback is called.
 *
 * Returns: A submitted transaction or NULL on failure.
 */
static struct cvmx_usb_transaction *cvmx_usb_submit_interrupt(
                                                struct octeon_hcd *usb,
                                                struct cvmx_usb_pipe *pipe,
                                                struct urb *urb)
{
        return cvmx_usb_submit_transaction(usb, pipe,
                                           CVMX_USB_TRANSFER_INTERRUPT,
                                           urb->transfer_dma,
                                           urb->transfer_buffer_length,
                                           0, /* control_header */
                                           0, /* iso_start_frame */
                                           0, /* iso_number_packets */
                                           NULL, /* iso_packets */
                                           urb);
}

/**
 * Call to submit a USB Control transfer to a pipe.
 *
 * @usb:            USB device state populated by cvmx_usb_initialize().
 * @pipe:           Handle to the pipe for the transfer.
 * @urb:            URB.
 *
 * Returns: A submitted transaction or NULL on failure.
 */
static struct cvmx_usb_transaction *cvmx_usb_submit_control(
                                                struct octeon_hcd *usb,
                                                struct cvmx_usb_pipe *pipe,
                                                struct urb *urb)
{
        int buffer_length = urb->transfer_buffer_length;
        u64 control_header = urb->setup_dma;
        struct usb_ctrlrequest *header = cvmx_phys_to_ptr(control_header);

        if ((header->bRequestType & USB_DIR_IN) == 0)
                buffer_length = le16_to_cpu(header->wLength);

        return cvmx_usb_submit_transaction(usb, pipe,
                                           CVMX_USB_TRANSFER_CONTROL,
                                           urb->transfer_dma, buffer_length,
                                           control_header,
                                           0, /* iso_start_frame */
                                           0, /* iso_number_packets */
                                           NULL, /* iso_packets */
                                           urb);
}

/**
 * Call to submit a USB Isochronous transfer to a pipe.
 *
 * @usb:            USB device state populated by cvmx_usb_initialize().
 * @pipe:           Handle to the pipe for the transfer.
 * @urb:            URB returned when the callback is called.
 *
 * Returns: A submitted transaction or NULL on failure.
 */
static struct cvmx_usb_transaction *cvmx_usb_submit_isochronous(
                                                struct octeon_hcd *usb,
                                                struct cvmx_usb_pipe *pipe,
                                                struct urb *urb)
{
        struct cvmx_usb_iso_packet *packets;

        packets = (struct cvmx_usb_iso_packet *)urb->setup_packet;
        return cvmx_usb_submit_transaction(usb, pipe,
                                           CVMX_USB_TRANSFER_ISOCHRONOUS,
                                           urb->transfer_dma,
                                           urb->transfer_buffer_length,
                                           0, /* control_header */
                                           urb->start_frame,
                                           urb->number_of_packets,
                                           packets, urb);
}

/**
 * Cancel one outstanding request in a pipe. Canceling a request
 * can fail if the transaction has already completed before cancel
 * is called. Even after a successful cancel call, it may take
 * a frame or two for the cvmx_usb_poll() function to call the
 * associated callback.
 *
 * @usb:         USB device state populated by cvmx_usb_initialize().
 * @pipe:        Pipe to cancel requests in.
 * @transaction: Transaction to cancel, returned by the submit function.
 *
 * Returns: 0 or a negative error code.
 */
static int cvmx_usb_cancel(struct octeon_hcd *usb,
                           struct cvmx_usb_pipe *pipe,
                           struct cvmx_usb_transaction *transaction)
{
        /*
         * If the transaction is the HEAD of the queue and scheduled. We need to
         * treat it special
         */
        if (list_first_entry(&pipe->transactions, typeof(*transaction), node) ==
            transaction && (pipe->flags & CVMX_USB_PIPE_FLAGS_SCHEDULED)) {
                union cvmx_usbcx_hccharx usbc_hcchar;

                usb->pipe_for_channel[pipe->channel] = NULL;
                pipe->flags &= ~CVMX_USB_PIPE_FLAGS_SCHEDULED;

                CVMX_SYNCW;

                usbc_hcchar.u32 = cvmx_usb_read_csr32(usb,
                                CVMX_USBCX_HCCHARX(pipe->channel, usb->index));
                /*
                 * If the channel isn't enabled then the transaction already
                 * completed.
                 */
                if (usbc_hcchar.s.chena) {
                        usbc_hcchar.s.chdis = 1;
                        cvmx_usb_write_csr32(usb,
                                             CVMX_USBCX_HCCHARX(pipe->channel,
                                                                usb->index),
                                             usbc_hcchar.u32);
                }
        }
        cvmx_usb_complete(usb, pipe, transaction, CVMX_USB_STATUS_CANCEL);
        return 0;
}

/**
 * Cancel all outstanding requests in a pipe. Logically all this
 * does is call cvmx_usb_cancel() in a loop.
 *
 * @usb:         USB device state populated by cvmx_usb_initialize().
 * @pipe:        Pipe to cancel requests in.
 *
 * Returns: 0 or a negative error code.
 */
static int cvmx_usb_cancel_all(struct octeon_hcd *usb,
                               struct cvmx_usb_pipe *pipe)
{
        struct cvmx_usb_transaction *transaction, *next;

        /* Simply loop through and attempt to cancel each transaction */
        list_for_each_entry_safe(transaction, next, &pipe->transactions, node) {
                int result = cvmx_usb_cancel(usb, pipe, transaction);

                if (unlikely(result != 0))
                        return result;
        }
        return 0;
}

/**
 * Close a pipe created with cvmx_usb_open_pipe().
 *
 * @usb:         USB device state populated by cvmx_usb_initialize().
 * @pipe:        Pipe to close.
 *
 * Returns: 0 or a negative error code. EBUSY is returned if the pipe has
 *          outstanding transfers.
 */
static int cvmx_usb_close_pipe(struct octeon_hcd *usb,
                               struct cvmx_usb_pipe *pipe)
{
        /* Fail if the pipe has pending transactions */
        if (!list_empty(&pipe->transactions))
                return -EBUSY;

        list_del(&pipe->node);
        kfree(pipe);

        return 0;
}

/**
 * Get the current USB protocol level frame number. The frame
 * number is always in the range of 0-0x7ff.
 *
 * @usb: USB device state populated by cvmx_usb_initialize().
 *
 * Returns: USB frame number
 */
static int cvmx_usb_get_frame_number(struct octeon_hcd *usb)
{
        union cvmx_usbcx_hfnum usbc_hfnum;

        usbc_hfnum.u32 = cvmx_usb_read_csr32(usb, CVMX_USBCX_HFNUM(usb->index));

        return usbc_hfnum.s.frnum;
}

static void cvmx_usb_transfer_control(struct octeon_hcd *usb,
                                      struct cvmx_usb_pipe *pipe,
                                      struct cvmx_usb_transaction *transaction,
                                      union cvmx_usbcx_hccharx usbc_hcchar,
                                      int buffer_space_left,
                                      int bytes_in_last_packet)
{
        switch (transaction->stage) {
        case CVMX_USB_STAGE_NON_CONTROL:
        case CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE:
                /* This should be impossible */
                cvmx_usb_complete(usb, pipe, transaction,
                                  CVMX_USB_STATUS_ERROR);
                break;
        case CVMX_USB_STAGE_SETUP:
                pipe->pid_toggle = 1;
                if (cvmx_usb_pipe_needs_split(usb, pipe)) {
                        transaction->stage =
                                CVMX_USB_STAGE_SETUP_SPLIT_COMPLETE;
                } else {
                        struct usb_ctrlrequest *header =
                                cvmx_phys_to_ptr(transaction->control_header);
                        if (header->wLength)
                                transaction->stage = CVMX_USB_STAGE_DATA;
                        else
                                transaction->stage = CVMX_USB_STAGE_STATUS;
                }
                break;
        case CVMX_USB_STAGE_SETUP_SPLIT_COMPLETE:
                {
                        struct usb_ctrlrequest *header =
                                cvmx_phys_to_ptr(transaction->control_header);
                        if (header->wLength)
                                transaction->stage = CVMX_USB_STAGE_DATA;
                        else
                                transaction->stage = CVMX_USB_STAGE_STATUS;
                }
                break;
        case CVMX_USB_STAGE_DATA:
                if (cvmx_usb_pipe_needs_split(usb, pipe)) {
                        transaction->stage = CVMX_USB_STAGE_DATA_SPLIT_COMPLETE;
                        /*
                         * For setup OUT data that are splits,
                         * the hardware doesn't appear to count
                         * transferred data. Here we manually
                         * update the data transferred
                         */
                        if (!usbc_hcchar.s.epdir) {
                                if (buffer_space_left < pipe->max_packet)
                                        transaction->actual_bytes +=
                                                buffer_space_left;
                                else
                                        transaction->actual_bytes +=
                                                pipe->max_packet;
                        }
                } else if ((buffer_space_left == 0) ||
                           (bytes_in_last_packet < pipe->max_packet)) {
                        pipe->pid_toggle = 1;
                        transaction->stage = CVMX_USB_STAGE_STATUS;
                }
                break;
        case CVMX_USB_STAGE_DATA_SPLIT_COMPLETE:
                if ((buffer_space_left == 0) ||
                    (bytes_in_last_packet < pipe->max_packet)) {
                        pipe->pid_toggle = 1;
                        transaction->stage = CVMX_USB_STAGE_STATUS;
                } else {
                        transaction->stage = CVMX_USB_STAGE_DATA;
                }
                break;
        case CVMX_USB_STAGE_STATUS:
                if (cvmx_usb_pipe_needs_split(usb, pipe))
                        transaction->stage =
                                CVMX_USB_STAGE_STATUS_SPLIT_COMPLETE;
                else
                        cvmx_usb_complete(usb, pipe, transaction,
                                          CVMX_USB_STATUS_OK);
                break;
        case CVMX_USB_STAGE_STATUS_SPLIT_COMPLETE:
                cvmx_usb_complete(usb, pipe, transaction, CVMX_USB_STATUS_OK);
                break;
        }
}

static void cvmx_usb_transfer_bulk(struct octeon_hcd *usb,
                                   struct cvmx_usb_pipe *pipe,
                                   struct cvmx_usb_transaction *transaction,
                                   union cvmx_usbcx_hcintx usbc_hcint,
                                   int buffer_space_left,
                                   int bytes_in_last_packet)
{
        /*
         * The only time a bulk transfer isn't complete when it finishes with
         * an ACK is during a split transaction. For splits we need to continue
         * the transfer if more data is needed.
         */
        if (cvmx_usb_pipe_needs_split(usb, pipe)) {
                if (transaction->stage == CVMX_USB_STAGE_NON_CONTROL)
                        transaction->stage =
                                CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE;
                else if (buffer_space_left &&
                         (bytes_in_last_packet == pipe->max_packet))
                        transaction->stage = CVMX_USB_STAGE_NON_CONTROL;
                else
                        cvmx_usb_complete(usb, pipe, transaction,
                                          CVMX_USB_STATUS_OK);
        } else {
                if ((pipe->device_speed == CVMX_USB_SPEED_HIGH) &&
                    (pipe->transfer_dir == CVMX_USB_DIRECTION_OUT) &&
                    (usbc_hcint.s.nak))
                        pipe->flags |= CVMX_USB_PIPE_FLAGS_NEED_PING;
                if (!buffer_space_left ||
                    (bytes_in_last_packet < pipe->max_packet))
                        cvmx_usb_complete(usb, pipe, transaction,
                                          CVMX_USB_STATUS_OK);
        }
}

static void cvmx_usb_transfer_intr(struct octeon_hcd *usb,
                                   struct cvmx_usb_pipe *pipe,
                                   struct cvmx_usb_transaction *transaction,
                                   int buffer_space_left,
                                   int bytes_in_last_packet)
{
        if (cvmx_usb_pipe_needs_split(usb, pipe)) {
                if (transaction->stage == CVMX_USB_STAGE_NON_CONTROL) {
                        transaction->stage =
                                CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE;
                } else if (buffer_space_left &&
                           (bytes_in_last_packet == pipe->max_packet)) {
                        transaction->stage = CVMX_USB_STAGE_NON_CONTROL;
                } else {
                        pipe->next_tx_frame += pipe->interval;
                        cvmx_usb_complete(usb, pipe, transaction,
                                          CVMX_USB_STATUS_OK);
                }
        } else if (!buffer_space_left ||
                   (bytes_in_last_packet < pipe->max_packet)) {
                pipe->next_tx_frame += pipe->interval;
                cvmx_usb_complete(usb, pipe, transaction, CVMX_USB_STATUS_OK);
        }
}

static void cvmx_usb_transfer_isoc(struct octeon_hcd *usb,
                                   struct cvmx_usb_pipe *pipe,
                                   struct cvmx_usb_transaction *transaction,
                                   int buffer_space_left,
                                   int bytes_in_last_packet,
                                   int bytes_this_transfer)
{
        if (cvmx_usb_pipe_needs_split(usb, pipe)) {
                /*
                 * ISOCHRONOUS OUT splits don't require a complete split stage.
                 * Instead they use a sequence of begin OUT splits to transfer
                 * the data 188 bytes at a time. Once the transfer is complete,
                 * the pipe sleeps until the next schedule interval.
                 */
                if (pipe->transfer_dir == CVMX_USB_DIRECTION_OUT) {
                        /*
                         * If no space left or this wasn't a max size packet
                         * then this transfer is complete. Otherwise start it
                         * again to send the next 188 bytes
                         */
                        if (!buffer_space_left || (bytes_this_transfer < 188)) {
                                pipe->next_tx_frame += pipe->interval;
                                cvmx_usb_complete(usb, pipe, transaction,
                                                  CVMX_USB_STATUS_OK);
                        }
                        return;
                }
                if (transaction->stage ==
                    CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE) {
                        /*
                         * We are in the incoming data phase. Keep getting data
                         * until we run out of space or get a small packet
                         */
                        if ((buffer_space_left == 0) ||
                            (bytes_in_last_packet < pipe->max_packet)) {
                                pipe->next_tx_frame += pipe->interval;
                                cvmx_usb_complete(usb, pipe, transaction,
                                                  CVMX_USB_STATUS_OK);
                        }
                } else {
                        transaction->stage =
                                CVMX_USB_STAGE_NON_CONTROL_SPLIT_COMPLETE;
                }
        } else {
                pipe->next_tx_frame += pipe->interval;
                cvmx_usb_complete(usb, pipe, transaction, CVMX_USB_STATUS_OK);
        }
}

/**
 * Poll a channel for status
 *
 * @usb:     USB device
 * @channel: Channel to poll
 *
 * Returns: Zero on success
 */
static int cvmx_usb_poll_channel(struct octeon_hcd *usb, int channel)
{
        struct usb_hcd *hcd = octeon_to_hcd(usb);
        struct device *dev = hcd->self.controller;
        union cvmx_usbcx_hcintx usbc_hcint;
        union cvmx_usbcx_hctsizx usbc_hctsiz;
        union cvmx_usbcx_hccharx usbc_hcchar;
        struct cvmx_usb_pipe *pipe;
        struct cvmx_usb_transaction *transaction;
        int bytes_this_transfer;
        int bytes_in_last_packet;
        int packets_processed;
        int buffer_space_left;

        /* Read the interrupt status bits for the channel */
        usbc_hcint.u32 = cvmx_usb_read_csr32(usb,
                                CVMX_USBCX_HCINTX(channel, usb->index));

        if (usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_NO_DMA) {
                usbc_hcchar.u32 = cvmx_usb_read_csr32(usb,
                                CVMX_USBCX_HCCHARX(channel, usb->index));

                if (usbc_hcchar.s.chena && usbc_hcchar.s.chdis) {
                        /*
                         * There seems to be a bug in CN31XX which can cause
                         * interrupt IN transfers to get stuck until we do a
                         * write of HCCHARX without changing things
                         */
                        cvmx_usb_write_csr32(usb,
                                             CVMX_USBCX_HCCHARX(channel,
                                                                usb->index),
                                             usbc_hcchar.u32);
                        return 0;
                }

                /*
                 * In non DMA mode the channels don't halt themselves. We need
                 * to manually disable channels that are left running
                 */
                if (!usbc_hcint.s.chhltd) {
                        if (usbc_hcchar.s.chena) {
                                union cvmx_usbcx_hcintmskx hcintmsk;
                                /* Disable all interrupts except CHHLTD */
                                hcintmsk.u32 = 0;
                                hcintmsk.s.chhltdmsk = 1;
                                cvmx_usb_write_csr32(usb,
                                                     CVMX_USBCX_HCINTMSKX(channel, usb->index),
                                                     hcintmsk.u32);
                                usbc_hcchar.s.chdis = 1;
                                cvmx_usb_write_csr32(usb,
                                                     CVMX_USBCX_HCCHARX(channel, usb->index),
                                                     usbc_hcchar.u32);
                                return 0;
                        } else if (usbc_hcint.s.xfercompl) {
                                /*
                                 * Successful IN/OUT with transfer complete.
                                 * Channel halt isn't needed.
                                 */
                        } else {
                                dev_err(dev, "USB%d: Channel %d interrupt without halt\n",
                                        usb->index, channel);
                                return 0;
                        }
                }
        } else {
                /*
                 * There is are no interrupts that we need to process when the
                 * channel is still running
                 */
                if (!usbc_hcint.s.chhltd)
                        return 0;
        }

        /* Disable the channel interrupts now that it is done */
        cvmx_usb_write_csr32(usb, CVMX_USBCX_HCINTMSKX(channel, usb->index), 0);
        usb->idle_hardware_channels |= (1 << channel);

        /* Make sure this channel is tied to a valid pipe */
        pipe = usb->pipe_for_channel[channel];
        prefetch(pipe);
        if (!pipe)
                return 0;
        transaction = list_first_entry(&pipe->transactions,
                                       typeof(*transaction),
                                       node);
        prefetch(transaction);

        /*
         * Disconnect this pipe from the HW channel. Later the schedule
         * function will figure out which pipe needs to go
         */
        usb->pipe_for_channel[channel] = NULL;
        pipe->flags &= ~CVMX_USB_PIPE_FLAGS_SCHEDULED;

        /*
         * Read the channel config info so we can figure out how much data
         * transferred
         */
        usbc_hcchar.u32 = cvmx_usb_read_csr32(usb,
                        CVMX_USBCX_HCCHARX(channel, usb->index));
        usbc_hctsiz.u32 = cvmx_usb_read_csr32(usb,
                        CVMX_USBCX_HCTSIZX(channel, usb->index));

        /*
         * Calculating the number of bytes successfully transferred is dependent
         * on the transfer direction
         */
        packets_processed = transaction->pktcnt - usbc_hctsiz.s.pktcnt;
        if (usbc_hcchar.s.epdir) {
                /*
                 * IN transactions are easy. For every byte received the
                 * hardware decrements xfersize. All we need to do is subtract
                 * the current value of xfersize from its starting value and we
                 * know how many bytes were written to the buffer
                 */
                bytes_this_transfer = transaction->xfersize -
                        usbc_hctsiz.s.xfersize;
        } else {
                /*
                 * OUT transaction don't decrement xfersize. Instead pktcnt is
                 * decremented on every successful packet send. The hardware
                 * does this when it receives an ACK, or NYET. If it doesn't
                 * receive one of these responses pktcnt doesn't change
                 */
                bytes_this_transfer = packets_processed * usbc_hcchar.s.mps;
                /*
                 * The last packet may not be a full transfer if we didn't have
                 * enough data
                 */
                if (bytes_this_transfer > transaction->xfersize)
                        bytes_this_transfer = transaction->xfersize;
        }
        /* Figure out how many bytes were in the last packet of the transfer */
        if (packets_processed)
                bytes_in_last_packet = bytes_this_transfer -
                        (packets_processed - 1) * usbc_hcchar.s.mps;
        else
                bytes_in_last_packet = bytes_this_transfer;

        /*
         * As a special case, setup transactions output the setup header, not
         * the user's data. For this reason we don't count setup data as bytes
         * transferred
         */
        if ((transaction->stage == CVMX_USB_STAGE_SETUP) ||
            (transaction->stage == CVMX_USB_STAGE_SETUP_SPLIT_COMPLETE))
                bytes_this_transfer = 0;

        /*
         * Add the bytes transferred to the running total. It is important that
         * bytes_this_transfer doesn't count any data that needs to be
         * retransmitted
         */
        transaction->actual_bytes += bytes_this_transfer;
        if (transaction->type == CVMX_USB_TRANSFER_ISOCHRONOUS)
                buffer_space_left = transaction->iso_packets[0].length -
                        transaction->actual_bytes;
        else
                buffer_space_left = transaction->buffer_length -
                        transaction->actual_bytes;

        /*
         * We need to remember the PID toggle state for the next transaction.
         * The hardware already updated it for the next transaction
         */
        pipe->pid_toggle = !(usbc_hctsiz.s.pid == 0);

        /*
         * For high speed bulk out, assume the next transaction will need to do
         * a ping before proceeding. If this isn't true the ACK processing below
         * will clear this flag
         */
        if ((pipe->device_speed == CVMX_USB_SPEED_HIGH) &&
            (pipe->transfer_type == CVMX_USB_TRANSFER_BULK) &&
            (pipe->transfer_dir == CVMX_USB_DIRECTION_OUT))
                pipe->flags |= CVMX_USB_PIPE_FLAGS_NEED_PING;

        if (WARN_ON_ONCE(bytes_this_transfer < 0)) {
                /*
                 * In some rare cases the DMA engine seems to get stuck and
                 * keeps substracting same byte count over and over again. In
                 * such case we just need to fail every transaction.
                 */
                cvmx_usb_complete(usb, pipe, transaction,
                                  CVMX_USB_STATUS_ERROR);
                return 0;
        }

        if (usbc_hcint.s.stall) {
                /*
                 * STALL as a response means this transaction cannot be
                 * completed because the device can't process transactions. Tell
                 * the user. Any data that was transferred will be counted on
                 * the actual bytes transferred
                 */
                pipe->pid_toggle = 0;
                cvmx_usb_complete(usb, pipe, transaction,
                                  CVMX_USB_STATUS_STALL);
        } else if (usbc_hcint.s.xacterr) {
                /*
                 * XactErr as a response means the device signaled
                 * something wrong with the transfer. For example, PID
                 * toggle errors cause these.
                 */
                cvmx_usb_complete(usb, pipe, transaction,
                                  CVMX_USB_STATUS_XACTERR);
        } else if (usbc_hcint.s.bblerr) {
                /* Babble Error (BblErr) */
                cvmx_usb_complete(usb, pipe, transaction,
                                  CVMX_USB_STATUS_BABBLEERR);
        } else if (usbc_hcint.s.datatglerr) {
                /* Data toggle error */
                cvmx_usb_complete(usb, pipe, transaction,
                                  CVMX_USB_STATUS_DATATGLERR);
        } else if (usbc_hcint.s.nyet) {
                /*
                 * NYET as a response is only allowed in three cases: as a
                 * response to a ping, as a response to a split transaction, and
                 * as a response to a bulk out. The ping case is handled by
                 * hardware, so we only have splits and bulk out
                 */
                if (!cvmx_usb_pipe_needs_split(usb, pipe)) {
                        transaction->retries = 0;
                        /*
                         * If there is more data to go then we need to try
                         * again. Otherwise this transaction is complete
                         */
                        if ((buffer_space_left == 0) ||
                            (bytes_in_last_packet < pipe->max_packet))
                                cvmx_usb_complete(usb, pipe,
                                                  transaction,
                                                  CVMX_USB_STATUS_OK);
                } else {
                        /*
                         * Split transactions retry the split complete 4 times
                         * then rewind to the start split and do the entire
                         * transactions again
                         */
                        transaction->retries++;
                        if ((transaction->retries & 0x3) == 0) {
                                /*
                                 * Rewind to the beginning of the transaction by
                                 * anding off the split complete bit
                                 */
                                transaction->stage &= ~1;
                                pipe->split_sc_frame = -1;
                        }
                }
        } else if (usbc_hcint.s.ack) {
                transaction->retries = 0;
                /*
                 * The ACK bit can only be checked after the other error bits.
                 * This is because a multi packet transfer may succeed in a
                 * number of packets and then get a different response on the
                 * last packet. In this case both ACK and the last response bit
                 * will be set. If none of the other response bits is set, then
                 * the last packet must have been an ACK
                 *
                 * Since we got an ACK, we know we don't need to do a ping on
                 * this pipe
                 */
                pipe->flags &= ~CVMX_USB_PIPE_FLAGS_NEED_PING;

                switch (transaction->type) {
                case CVMX_USB_TRANSFER_CONTROL:
                        cvmx_usb_transfer_control(usb, pipe, transaction,
                                                  usbc_hcchar,
                                                  buffer_space_left,
                                                  bytes_in_last_packet);
                        break;
                case CVMX_USB_TRANSFER_BULK:
                        cvmx_usb_transfer_bulk(usb, pipe, transaction,
                                               usbc_hcint, buffer_space_left,
                                               bytes_in_last_packet);
                        break;
                case CVMX_USB_TRANSFER_INTERRUPT:
                        cvmx_usb_transfer_intr(usb, pipe, transaction,
                                               buffer_space_left,
                                               bytes_in_last_packet);
                        break;
                case CVMX_USB_TRANSFER_ISOCHRONOUS:
                        cvmx_usb_transfer_isoc(usb, pipe, transaction,
                                               buffer_space_left,
                                               bytes_in_last_packet,
                                               bytes_this_transfer);
                        break;
                }
        } else if (usbc_hcint.s.nak) {
                /*
                 * If this was a split then clear our split in progress marker.
                 */
                if (usb->active_split == transaction)
                        usb->active_split = NULL;
                /*
                 * NAK as a response means the device couldn't accept the
                 * transaction, but it should be retried in the future. Rewind
                 * to the beginning of the transaction by anding off the split
                 * complete bit. Retry in the next interval
                 */
                transaction->retries = 0;
                transaction->stage &= ~1;
                pipe->next_tx_frame += pipe->interval;
                if (pipe->next_tx_frame < usb->frame_number)
                        pipe->next_tx_frame = usb->frame_number +
                                pipe->interval -
                                (usb->frame_number - pipe->next_tx_frame) %
                                pipe->interval;
        } else {
                struct cvmx_usb_port_status port;

                port = cvmx_usb_get_status(usb);
                if (port.port_enabled) {
                        /* We'll retry the exact same transaction again */
                        transaction->retries++;
                } else {
                        /*
                         * We get channel halted interrupts with no result bits
                         * sets when the cable is unplugged
                         */
                        cvmx_usb_complete(usb, pipe, transaction,
                                          CVMX_USB_STATUS_ERROR);
                }
        }
        return 0;
}

static void octeon_usb_port_callback(struct octeon_hcd *usb)
{
        spin_unlock(&usb->lock);
        usb_hcd_poll_rh_status(octeon_to_hcd(usb));
        spin_lock(&usb->lock);
}

/**
 * Poll the USB block for status and call all needed callback
 * handlers. This function is meant to be called in the interrupt
 * handler for the USB controller. It can also be called
 * periodically in a loop for non-interrupt based operation.
 *
 * @usb: USB device state populated by cvmx_usb_initialize().
 *
 * Returns: 0 or a negative error code.
 */
static int cvmx_usb_poll(struct octeon_hcd *usb)
{
        union cvmx_usbcx_hfnum usbc_hfnum;
        union cvmx_usbcx_gintsts usbc_gintsts;

        prefetch_range(usb, sizeof(*usb));

        /* Update the frame counter */
        usbc_hfnum.u32 = cvmx_usb_read_csr32(usb, CVMX_USBCX_HFNUM(usb->index));
        if ((usb->frame_number & 0x3fff) > usbc_hfnum.s.frnum)
                usb->frame_number += 0x4000;
        usb->frame_number &= ~0x3fffull;
        usb->frame_number |= usbc_hfnum.s.frnum;

        /* Read the pending interrupts */
        usbc_gintsts.u32 = cvmx_usb_read_csr32(usb,
                                               CVMX_USBCX_GINTSTS(usb->index));

        /* Clear the interrupts now that we know about them */
        cvmx_usb_write_csr32(usb, CVMX_USBCX_GINTSTS(usb->index),
                             usbc_gintsts.u32);

        if (usbc_gintsts.s.rxflvl) {
                /*
                 * RxFIFO Non-Empty (RxFLvl)
                 * Indicates that there is at least one packet pending to be
                 * read from the RxFIFO.
                 *
                 * In DMA mode this is handled by hardware
                 */
                if (usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_NO_DMA)
                        cvmx_usb_poll_rx_fifo(usb);
        }
        if (usbc_gintsts.s.ptxfemp || usbc_gintsts.s.nptxfemp) {
                /* Fill the Tx FIFOs when not in DMA mode */
                if (usb->init_flags & CVMX_USB_INITIALIZE_FLAGS_NO_DMA)
                        cvmx_usb_poll_tx_fifo(usb);
        }
        if (usbc_gintsts.s.disconnint || usbc_gintsts.s.prtint) {
                union cvmx_usbcx_hprt usbc_hprt;
                /*
                 * Disconnect Detected Interrupt (DisconnInt)
                 * Asserted when a device disconnect is detected.
                 *
                 * Host Port Interrupt (PrtInt)
                 * The core sets this bit to indicate a change in port status of
                 * one of the O2P USB core ports in Host mode. The application
                 * must read the Host Port Control and Status (HPRT) register to
                 * determine the exact event that caused this interrupt. The
                 * application must clear the appropriate status bit in the Host
                 * Port Control and Status register to clear this bit.
                 *
                 * Call the user's port callback
                 */
                octeon_usb_port_callback(usb);
                /* Clear the port change bits */
                usbc_hprt.u32 =
                        cvmx_usb_read_csr32(usb, CVMX_USBCX_HPRT(usb->index));
                usbc_hprt.s.prtena = 0;
                cvmx_usb_write_csr32(usb, CVMX_USBCX_HPRT(usb->index),
                                     usbc_hprt.u32);
        }
        if (usbc_gintsts.s.hchint) {
                /*
                 * Host Channels Interrupt (HChInt)
                 * The core sets this bit to indicate that an interrupt is
                 * pending on one of the channels of the core (in Host mode).
                 * The application must read the Host All Channels Interrupt
                 * (HAINT) register to determine the exact number of the channel
                 * on which the interrupt occurred, and then read the
                 * corresponding Host Channel-n Interrupt (HCINTn) register to
                 * determine the exact cause of the interrupt. The application
                 * must clear the appropriate status bit in the HCINTn register
                 * to clear this bit.
                 */
                union cvmx_usbcx_haint usbc_haint;

                usbc_haint.u32 = cvmx_usb_read_csr32(usb,
                                        CVMX_USBCX_HAINT(usb->index));
                while (usbc_haint.u32) {
                        int channel;

                        channel = __fls(usbc_haint.u32);
                        cvmx_usb_poll_channel(usb, channel);
                        usbc_haint.u32 ^= 1 << channel;
                }
        }

        cvmx_usb_schedule(usb, usbc_gintsts.s.sof);

        return 0;
}

/* convert between an HCD pointer and the corresponding struct octeon_hcd */
static inline struct octeon_hcd *hcd_to_octeon(struct usb_hcd *hcd)
{
        return (struct octeon_hcd *)(hcd->hcd_priv);
}

static irqreturn_t octeon_usb_irq(struct usb_hcd *hcd)
{
        struct octeon_hcd *usb = hcd_to_octeon(hcd);
        unsigned long flags;

        spin_lock_irqsave(&usb->lock, flags);
        cvmx_usb_poll(usb);
        spin_unlock_irqrestore(&usb->lock, flags);
        return IRQ_HANDLED;
}

static int octeon_usb_start(struct usb_hcd *hcd)
{
        hcd->state = HC_STATE_RUNNING;
        return 0;
}

static void octeon_usb_stop(struct usb_hcd *hcd)
{
        hcd->state = HC_STATE_HALT;
}

static int octeon_usb_get_frame_number(struct usb_hcd *hcd)
{
        struct octeon_hcd *usb = hcd_to_octeon(hcd);

        return cvmx_usb_get_frame_number(usb);
}

static int octeon_usb_urb_enqueue(struct usb_hcd *hcd,
                                  struct urb *urb,
                                  gfp_t mem_flags)
{
        struct octeon_hcd *usb = hcd_to_octeon(hcd);
        struct device *dev = hcd->self.controller;
        struct cvmx_usb_transaction *transaction = NULL;
        struct cvmx_usb_pipe *pipe;
        unsigned long flags;
        struct cvmx_usb_iso_packet *iso_packet;
        struct usb_host_endpoint *ep = urb->ep;
        int rc;

        urb->status = 0;
        spin_lock_irqsave(&usb->lock, flags);

        rc = usb_hcd_link_urb_to_ep(hcd, urb);
        if (rc) {
                spin_unlock_irqrestore(&usb->lock, flags);
                return rc;
        }

        if (!ep->hcpriv) {
                enum cvmx_usb_transfer transfer_type;
                enum cvmx_usb_speed speed;
                int split_device = 0;
                int split_port = 0;

                switch (usb_pipetype(urb->pipe)) {
                case PIPE_ISOCHRONOUS:
                        transfer_type = CVMX_USB_TRANSFER_ISOCHRONOUS;
                        break;
                case PIPE_INTERRUPT:
                        transfer_type = CVMX_USB_TRANSFER_INTERRUPT;
                        break;
                case PIPE_CONTROL:
                        transfer_type = CVMX_USB_TRANSFER_CONTROL;
                        break;
                default:
                        transfer_type = CVMX_USB_TRANSFER_BULK;
                        break;
                }
                switch (urb->dev->speed) {
                case USB_SPEED_LOW:
                        speed = CVMX_USB_SPEED_LOW;
                        break;
                case USB_SPEED_FULL:
                        speed = CVMX_USB_SPEED_FULL;
                        break;
                default:
                        speed = CVMX_USB_SPEED_HIGH;
                        break;
                }
                /*
                 * For slow devices on high speed ports we need to find the hub
                 * that does the speed translation so we know where to send the
                 * split transactions.
                 */
                if (speed != CVMX_USB_SPEED_HIGH) {
                        /*
                         * Start at this device and work our way up the usb
                         * tree.
                         */
                        struct usb_device *dev = urb->dev;

                        while (dev->parent) {
                                /*
                                 * If our parent is high speed then he'll
                                 * receive the splits.
                                 */
                                if (dev->parent->speed == USB_SPEED_HIGH) {
                                        split_device = dev->parent->devnum;
                                        split_port = dev->portnum;
                                        break;
                                }
                                /*
                                 * Move up the tree one level. If we make it all
                                 * the way up the tree, then the port must not
                                 * be in high speed mode and we don't need a
                                 * split.
                                 */
                                dev = dev->parent;
                        }
                }
                pipe = cvmx_usb_open_pipe(usb, usb_pipedevice(urb->pipe),
                                          usb_pipeendpoint(urb->pipe), speed,
                                          le16_to_cpu(ep->desc.wMaxPacketSize)
                                          & 0x7ff,
                                          transfer_type,
                                          usb_pipein(urb->pipe) ?
                                                CVMX_USB_DIRECTION_IN :
                                                CVMX_USB_DIRECTION_OUT,
                                          urb->interval,
                                          (le16_to_cpu(ep->desc.wMaxPacketSize)
                                           >> 11) & 0x3,
                                          split_device, split_port);
                if (!pipe) {
                        usb_hcd_unlink_urb_from_ep(hcd, urb);
                        spin_unlock_irqrestore(&usb->lock, flags);
                        dev_dbg(dev, "Failed to create pipe\n");
                        return -ENOMEM;
                }
                ep->hcpriv = pipe;
        } else {
                pipe = ep->hcpriv;
        }

        switch (usb_pipetype(urb->pipe)) {
        case PIPE_ISOCHRONOUS:
                dev_dbg(dev, "Submit isochronous to %d.%d\n",
                        usb_pipedevice(urb->pipe),
                        usb_pipeendpoint(urb->pipe));
                /*
                 * Allocate a structure to use for our private list of
                 * isochronous packets.
                 */
                iso_packet = kmalloc_array(urb->number_of_packets,
                                           sizeof(struct cvmx_usb_iso_packet),
                                           GFP_ATOMIC);
                if (iso_packet) {
                        int i;
                        /* Fill the list with the data from the URB */
                        for (i = 0; i < urb->number_of_packets; i++) {
                                iso_packet[i].offset =
                                        urb->iso_frame_desc[i].offset;
                                iso_packet[i].length =
                                        urb->iso_frame_desc[i].length;
                                iso_packet[i].status = CVMX_USB_STATUS_ERROR;
                        }
                        /*
                         * Store a pointer to the list in the URB setup_packet
                         * field. We know this currently isn't being used and
                         * this saves us a bunch of logic.
                         */
                        urb->setup_packet = (char *)iso_packet;
                        transaction = cvmx_usb_submit_isochronous(usb,
                                                                  pipe, urb);
                        /*
                         * If submit failed we need to free our private packet
                         * list.
                         */
                        if (!transaction) {
                                urb->setup_packet = NULL;
                                kfree(iso_packet);
                        }
                }
                break;
        case PIPE_INTERRUPT:
                dev_dbg(dev, "Submit interrupt to %d.%d\n",
                        usb_pipedevice(urb->pipe),
                        usb_pipeendpoint(urb->pipe));
                transaction = cvmx_usb_submit_interrupt(usb, pipe, urb);
                break;
        case PIPE_CONTROL:
                dev_dbg(dev, "Submit control to %d.%d\n",
                        usb_pipedevice(urb->pipe),
                        usb_pipeendpoint(urb->pipe));
                transaction = cvmx_usb_submit_control(usb, pipe, urb);
                break;
        case PIPE_BULK:
                dev_dbg(dev, "Submit bulk to %d.%d\n",
                        usb_pipedevice(urb->pipe),
                        usb_pipeendpoint(urb->pipe));
                transaction = cvmx_usb_submit_bulk(usb, pipe, urb);
                break;
        }
        if (!transaction) {
                usb_hcd_unlink_urb_from_ep(hcd, urb);
                spin_unlock_irqrestore(&usb->lock, flags);
                dev_dbg(dev, "Failed to submit\n");
                return -ENOMEM;
        }
        urb->hcpriv = transaction;
        spin_unlock_irqrestore(&usb->lock, flags);
        return 0;
}

static int octeon_usb_urb_dequeue(struct usb_hcd *hcd,
                                  struct urb *urb,
                                  int status)
{
        struct octeon_hcd *usb = hcd_to_octeon(hcd);
        unsigned long flags;
        int rc;

        if (!urb->dev)
                return -EINVAL;

        spin_lock_irqsave(&usb->lock, flags);

        rc = usb_hcd_check_unlink_urb(hcd, urb, status);
        if (rc)
                goto out;

        urb->status = status;
        cvmx_usb_cancel(usb, urb->ep->hcpriv, urb->hcpriv);

out:
        spin_unlock_irqrestore(&usb->lock, flags);

        return rc;
}

static void octeon_usb_endpoint_disable(struct usb_hcd *hcd,
                                        struct usb_host_endpoint *ep)
{
        struct device *dev = hcd->self.controller;

        if (ep->hcpriv) {
                struct octeon_hcd *usb = hcd_to_octeon(hcd);
                struct cvmx_usb_pipe *pipe = ep->hcpriv;
                unsigned long flags;

                spin_lock_irqsave(&usb->lock, flags);
                cvmx_usb_cancel_all(usb, pipe);
                if (cvmx_usb_close_pipe(usb, pipe))
                        dev_dbg(dev, "Closing pipe %p failed\n", pipe);
                spin_unlock_irqrestore(&usb->lock, flags);
                ep->hcpriv = NULL;
        }
}

static int octeon_usb_hub_status_data(struct usb_hcd *hcd, char *buf)
{
        struct octeon_hcd *usb = hcd_to_octeon(hcd);
        struct cvmx_usb_port_status port_status;
        unsigned long flags;

        spin_lock_irqsave(&usb->lock, flags);
        port_status = cvmx_usb_get_status(usb);
        spin_unlock_irqrestore(&usb->lock, flags);
        buf[0] = port_status.connect_change << 1;

        return buf[0] != 0;
}

static int octeon_usb_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                                  u16 wIndex, char *buf, u16 wLength)
{
        struct octeon_hcd *usb = hcd_to_octeon(hcd);
        struct device *dev = hcd->self.controller;
        struct cvmx_usb_port_status usb_port_status;
        int port_status;
        struct usb_hub_descriptor *desc;
        unsigned long flags;

        switch (typeReq) {
        case ClearHubFeature:
                dev_dbg(dev, "ClearHubFeature\n");
                switch (wValue) {
                case C_HUB_LOCAL_POWER:
                case C_HUB_OVER_CURRENT:
                        /* Nothing required here */
                        break;
                default:
                        return -EINVAL;
                }
                break;
        case ClearPortFeature:
                dev_dbg(dev, "ClearPortFeature\n");
                if (wIndex != 1) {
                        dev_dbg(dev, " INVALID\n");
                        return -EINVAL;
                }

                switch (wValue) {
                case USB_PORT_FEAT_ENABLE:
                        dev_dbg(dev, " ENABLE\n");
                        spin_lock_irqsave(&usb->lock, flags);
                        cvmx_usb_disable(usb);
                        spin_unlock_irqrestore(&usb->lock, flags);
                        break;
                case USB_PORT_FEAT_SUSPEND:
                        dev_dbg(dev, " SUSPEND\n");
                        /* Not supported on Octeon */
                        break;
                case USB_PORT_FEAT_POWER:
                        dev_dbg(dev, " POWER\n");
                        /* Not supported on Octeon */
                        break;
                case USB_PORT_FEAT_INDICATOR:
                        dev_dbg(dev, " INDICATOR\n");
                        /* Port inidicator not supported */
                        break;
                case USB_PORT_FEAT_C_CONNECTION:
                        dev_dbg(dev, " C_CONNECTION\n");
                        /* Clears drivers internal connect status change flag */
                        spin_lock_irqsave(&usb->lock, flags);
                        usb->port_status = cvmx_usb_get_status(usb);
                        spin_unlock_irqrestore(&usb->lock, flags);
                        break;
                case USB_PORT_FEAT_C_RESET:
                        dev_dbg(dev, " C_RESET\n");
                        /*
                         * Clears the driver's internal Port Reset Change flag.
                         */
                        spin_lock_irqsave(&usb->lock, flags);
                        usb->port_status = cvmx_usb_get_status(usb);
                        spin_unlock_irqrestore(&usb->lock, flags);
                        break;
                case USB_PORT_FEAT_C_ENABLE:
                        dev_dbg(dev, " C_ENABLE\n");
                        /*
                         * Clears the driver's internal Port Enable/Disable
                         * Change flag.
                         */
                        spin_lock_irqsave(&usb->lock, flags);
                        usb->port_status = cvmx_usb_get_status(usb);
                        spin_unlock_irqrestore(&usb->lock, flags);
                        break;
                case USB_PORT_FEAT_C_SUSPEND:
                        dev_dbg(dev, " C_SUSPEND\n");
                        /*
                         * Clears the driver's internal Port Suspend Change
                         * flag, which is set when resume signaling on the host
                         * port is complete.
                         */
                        break;
                case USB_PORT_FEAT_C_OVER_CURRENT:
                        dev_dbg(dev, " C_OVER_CURRENT\n");
                        /* Clears the driver's overcurrent Change flag */
                        spin_lock_irqsave(&usb->lock, flags);
                        usb->port_status = cvmx_usb_get_status(usb);
                        spin_unlock_irqrestore(&usb->lock, flags);
                        break;
                default:
                        dev_dbg(dev, " UNKNOWN\n");
                        return -EINVAL;
                }
                break;
        case GetHubDescriptor:
                dev_dbg(dev, "GetHubDescriptor\n");
                desc = (struct usb_hub_descriptor *)buf;
                desc->bDescLength = 9;
                desc->bDescriptorType = 0x29;
                desc->bNbrPorts = 1;
                desc->wHubCharacteristics = cpu_to_le16(0x08);
                desc->bPwrOn2PwrGood = 1;
                desc->bHubContrCurrent = 0;
                desc->u.hs.DeviceRemovable[0] = 0;
                desc->u.hs.DeviceRemovable[1] = 0xff;
                break;
        case GetHubStatus:
                dev_dbg(dev, "GetHubStatus\n");
                *(__le32 *)buf = 0;
                break;
        case GetPortStatus:
                dev_dbg(dev, "GetPortStatus\n");
                if (wIndex != 1) {
                        dev_dbg(dev, " INVALID\n");
                        return -EINVAL;
                }

                spin_lock_irqsave(&usb->lock, flags);
                usb_port_status = cvmx_usb_get_status(usb);
                spin_unlock_irqrestore(&usb->lock, flags);
                port_status = 0;

                if (usb_port_status.connect_change) {
                        port_status |= (1 << USB_PORT_FEAT_C_CONNECTION);
                        dev_dbg(dev, " C_CONNECTION\n");
                }

                if (usb_port_status.port_enabled) {
                        port_status |= (1 << USB_PORT_FEAT_C_ENABLE);
                        dev_dbg(dev, " C_ENABLE\n");
                }

                if (usb_port_status.connected) {
                        port_status |= (1 << USB_PORT_FEAT_CONNECTION);
                        dev_dbg(dev, " CONNECTION\n");
                }

                if (usb_port_status.port_enabled) {
                        port_status |= (1 << USB_PORT_FEAT_ENABLE);
                        dev_dbg(dev, " ENABLE\n");
                }

                if (usb_port_status.port_over_current) {
                        port_status |= (1 << USB_PORT_FEAT_OVER_CURRENT);
                        dev_dbg(dev, " OVER_CURRENT\n");
                }

                if (usb_port_status.port_powered) {
                        port_status |= (1 << USB_PORT_FEAT_POWER);
                        dev_dbg(dev, " POWER\n");
                }

                if (usb_port_status.port_speed == CVMX_USB_SPEED_HIGH) {
                        port_status |= USB_PORT_STAT_HIGH_SPEED;
                        dev_dbg(dev, " HIGHSPEED\n");
                } else if (usb_port_status.port_speed == CVMX_USB_SPEED_LOW) {
                        port_status |= (1 << USB_PORT_FEAT_LOWSPEED);
                        dev_dbg(dev, " LOWSPEED\n");
                }

                *((__le32 *)buf) = cpu_to_le32(port_status);
                break;
        case SetHubFeature:
                dev_dbg(dev, "SetHubFeature\n");
                /* No HUB features supported */
                break;
        case SetPortFeature:
                dev_dbg(dev, "SetPortFeature\n");
                if (wIndex != 1) {
                        dev_dbg(dev, " INVALID\n");
                        return -EINVAL;
                }

                switch (wValue) {
                case USB_PORT_FEAT_SUSPEND:
                        dev_dbg(dev, " SUSPEND\n");
                        return -EINVAL;
                case USB_PORT_FEAT_POWER:
                        dev_dbg(dev, " POWER\n");
                        /*
                         * Program the port power bit to drive VBUS on the USB.
                         */
                        spin_lock_irqsave(&usb->lock, flags);
                        USB_SET_FIELD32(CVMX_USBCX_HPRT(usb->index),
                                        cvmx_usbcx_hprt, prtpwr, 1);
                        spin_unlock_irqrestore(&usb->lock, flags);
                        return 0;
                case USB_PORT_FEAT_RESET:
                        dev_dbg(dev, " RESET\n");
                        spin_lock_irqsave(&usb->lock, flags);
                        cvmx_usb_reset_port(usb);
                        spin_unlock_irqrestore(&usb->lock, flags);
                        return 0;
                case USB_PORT_FEAT_INDICATOR:
                        dev_dbg(dev, " INDICATOR\n");
                        /* Not supported */
                        break;
                default:
                        dev_dbg(dev, " UNKNOWN\n");
                        return -EINVAL;
                }
                break;
        default:
                dev_dbg(dev, "Unknown root hub request\n");
                return -EINVAL;
        }
        return 0;
}

static const struct hc_driver octeon_hc_driver = {
        .description            = "Octeon USB",
        .product_desc           = "Octeon Host Controller",
        .hcd_priv_size          = sizeof(struct octeon_hcd),
        .irq                    = octeon_usb_irq,
        .flags                  = HCD_MEMORY | HCD_DMA | HCD_USB2,
        .start                  = octeon_usb_start,
        .stop                   = octeon_usb_stop,
        .urb_enqueue            = octeon_usb_urb_enqueue,
        .urb_dequeue            = octeon_usb_urb_dequeue,
        .endpoint_disable       = octeon_usb_endpoint_disable,
        .get_frame_number       = octeon_usb_get_frame_number,
        .hub_status_data        = octeon_usb_hub_status_data,
        .hub_control            = octeon_usb_hub_control,
        .map_urb_for_dma        = octeon_map_urb_for_dma,
        .unmap_urb_for_dma      = octeon_unmap_urb_for_dma,
};

static int octeon_usb_probe(struct platform_device *pdev)
{
        int status;
        int initialize_flags;
        int usb_num;
        struct resource *res_mem;
        struct device_node *usbn_node;
        int irq = platform_get_irq(pdev, 0);
        struct device *dev = &pdev->dev;
        struct octeon_hcd *usb;
        struct usb_hcd *hcd;
        u32 clock_rate = 48000000;
        bool is_crystal_clock = false;
        const char *clock_type;
        int i;

        if (!dev->of_node) {
                dev_err(dev, "Error: empty of_node\n");
                return -ENXIO;
        }
        usbn_node = dev->of_node->parent;

        i = of_property_read_u32(usbn_node,
                                 "clock-frequency", &clock_rate);
        if (i)
                i = of_property_read_u32(usbn_node,
                                         "refclk-frequency", &clock_rate);
        if (i) {
                dev_err(dev, "No USBN \"clock-frequency\"\n");
                return -ENXIO;
        }
        switch (clock_rate) {
        case 12000000:
                initialize_flags = CVMX_USB_INITIALIZE_FLAGS_CLOCK_12MHZ;
                break;
        case 24000000:
                initialize_flags = CVMX_USB_INITIALIZE_FLAGS_CLOCK_24MHZ;
                break;
        case 48000000:
                initialize_flags = CVMX_USB_INITIALIZE_FLAGS_CLOCK_48MHZ;
                break;
        default:
                dev_err(dev, "Illegal USBN \"clock-frequency\" %u\n",
                        clock_rate);
                return -ENXIO;
        }

        i = of_property_read_string(usbn_node,
                                    "cavium,refclk-type", &clock_type);
        if (i)
                i = of_property_read_string(usbn_node,
                                            "refclk-type", &clock_type);

        if (!i && strcmp("crystal", clock_type) == 0)
                is_crystal_clock = true;

        if (is_crystal_clock)
                initialize_flags |= CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_XI;
        else
                initialize_flags |= CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_GND;

        res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res_mem) {
                dev_err(dev, "found no memory resource\n");
                return -ENXIO;
        }
        usb_num = (res_mem->start >> 44) & 1;

        if (irq < 0) {
                /* Defective device tree, but we know how to fix it. */
                irq_hw_number_t hwirq = usb_num ? (1 << 6) + 17 : 56;

                irq = irq_create_mapping(NULL, hwirq);
        }

        /*
         * Set the DMA mask to 64bits so we get buffers already translated for
         * DMA.
         */
        i = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
        if (i)
                return i;

        /*
         * Only cn52XX and cn56XX have DWC_OTG USB hardware and the
         * IOB priority registers.  Under heavy network load USB
         * hardware can be starved by the IOB causing a crash.  Give
         * it a priority boost if it has been waiting more than 400
         * cycles to avoid this situation.
         *
         * Testing indicates that a cnt_val of 8192 is not sufficient,
         * but no failures are seen with 4096.  We choose a value of
         * 400 to give a safety factor of 10.
         */
        if (OCTEON_IS_MODEL(OCTEON_CN52XX) || OCTEON_IS_MODEL(OCTEON_CN56XX)) {
                union cvmx_iob_n2c_l2c_pri_cnt pri_cnt;

                pri_cnt.u64 = 0;
                pri_cnt.s.cnt_enb = 1;
                pri_cnt.s.cnt_val = 400;
                cvmx_write_csr(CVMX_IOB_N2C_L2C_PRI_CNT, pri_cnt.u64);
        }

        hcd = usb_create_hcd(&octeon_hc_driver, dev, dev_name(dev));
        if (!hcd) {
                dev_dbg(dev, "Failed to allocate memory for HCD\n");
                return -1;
        }
        hcd->uses_new_polling = 1;
        usb = (struct octeon_hcd *)hcd->hcd_priv;

        spin_lock_init(&usb->lock);

        usb->init_flags = initialize_flags;

        /* Initialize the USB state structure */
        usb->index = usb_num;
        INIT_LIST_HEAD(&usb->idle_pipes);
        for (i = 0; i < ARRAY_SIZE(usb->active_pipes); i++)
                INIT_LIST_HEAD(&usb->active_pipes[i]);

        /* Due to an errata, CN31XX doesn't support DMA */
        if (OCTEON_IS_MODEL(OCTEON_CN31XX)) {
                usb->init_flags |= CVMX_USB_INITIALIZE_FLAGS_NO_DMA;
                /* Only use one channel with non DMA */
                usb->idle_hardware_channels = 0x1;
        } else if (OCTEON_IS_MODEL(OCTEON_CN5XXX)) {
                /* CN5XXX have an errata with channel 3 */
                usb->idle_hardware_channels = 0xf7;
        } else {
                usb->idle_hardware_channels = 0xff;
        }

        status = cvmx_usb_initialize(dev, usb);
        if (status) {
                dev_dbg(dev, "USB initialization failed with %d\n", status);
                usb_put_hcd(hcd);
                return -1;
        }

        status = usb_add_hcd(hcd, irq, 0);
        if (status) {
                dev_dbg(dev, "USB add HCD failed with %d\n", status);
                usb_put_hcd(hcd);
                return -1;
        }
        device_wakeup_enable(hcd->self.controller);

        dev_info(dev, "Registered HCD for port %d on irq %d\n", usb_num, irq);

        return 0;
}

static int octeon_usb_remove(struct platform_device *pdev)
{
        int status;
        struct device *dev = &pdev->dev;
        struct usb_hcd *hcd = dev_get_drvdata(dev);
        struct octeon_hcd *usb = hcd_to_octeon(hcd);
        unsigned long flags;

        usb_remove_hcd(hcd);
        spin_lock_irqsave(&usb->lock, flags);
        status = cvmx_usb_shutdown(usb);
        spin_unlock_irqrestore(&usb->lock, flags);
        if (status)
                dev_dbg(dev, "USB shutdown failed with %d\n", status);

        usb_put_hcd(hcd);

        return 0;
}

static const struct of_device_id octeon_usb_match[] = {
        {
                .compatible = "cavium,octeon-5750-usbc",
        },
        {},
};
MODULE_DEVICE_TABLE(of, octeon_usb_match);

static struct platform_driver octeon_usb_driver = {
        .driver = {
                .name           = "octeon-hcd",
                .of_match_table = octeon_usb_match,
        },
        .probe      = octeon_usb_probe,
        .remove     = octeon_usb_remove,
};

static int __init octeon_usb_driver_init(void)
{
        if (usb_disabled())
                return 0;

        return platform_driver_register(&octeon_usb_driver);
}
module_init(octeon_usb_driver_init);

static void __exit octeon_usb_driver_exit(void)
{
        if (usb_disabled())
                return;

        platform_driver_unregister(&octeon_usb_driver);
}
module_exit(octeon_usb_driver_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Cavium, Inc. <support@cavium.com>");
MODULE_DESCRIPTION("Cavium Inc. OCTEON USB Host driver.");