Linux 4.9.89

[linux/fpc-iii.git] / drivers / usb / phy / phy-fsl-usb.c

/*
 * Copyright (C) 2007,2008 Freescale semiconductor, Inc.
 *
 * Author: Li Yang <LeoLi@freescale.com>
 *         Jerry Huang <Chang-Ming.Huang@freescale.com>
 *
 * Initialization based on code from Shlomi Gridish.
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the  GNU General Public License along
 * with this program; if not, write  to the Free Software Foundation, Inc.,
 * 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/timer.h>
#include <linux/usb.h>
#include <linux/device.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/workqueue.h>
#include <linux/time.h>
#include <linux/fsl_devices.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>

#include <asm/unaligned.h>

#include "phy-fsl-usb.h"

#define DRIVER_VERSION "Rev. 1.55"
#define DRIVER_AUTHOR "Jerry Huang/Li Yang"
#define DRIVER_DESC "Freescale USB OTG Transceiver Driver"
#define DRIVER_INFO DRIVER_DESC " " DRIVER_VERSION

static const char driver_name[] = "fsl-usb2-otg";

const pm_message_t otg_suspend_state = {
        .event = 1,
};

#define HA_DATA_PULSE

static struct usb_dr_mmap *usb_dr_regs;
static struct fsl_otg *fsl_otg_dev;
static int srp_wait_done;

/* FSM timers */
struct fsl_otg_timer *a_wait_vrise_tmr, *a_wait_bcon_tmr, *a_aidl_bdis_tmr,
        *b_ase0_brst_tmr, *b_se0_srp_tmr;

/* Driver specific timers */
struct fsl_otg_timer *b_data_pulse_tmr, *b_vbus_pulse_tmr, *b_srp_fail_tmr,
        *b_srp_wait_tmr, *a_wait_enum_tmr;

static struct list_head active_timers;

static struct fsl_otg_config fsl_otg_initdata = {
        .otg_port = 1,
};

#ifdef CONFIG_PPC32
static u32 _fsl_readl_be(const unsigned __iomem *p)
{
        return in_be32(p);
}

static u32 _fsl_readl_le(const unsigned __iomem *p)
{
        return in_le32(p);
}

static void _fsl_writel_be(u32 v, unsigned __iomem *p)
{
        out_be32(p, v);
}

static void _fsl_writel_le(u32 v, unsigned __iomem *p)
{
        out_le32(p, v);
}

static u32 (*_fsl_readl)(const unsigned __iomem *p);
static void (*_fsl_writel)(u32 v, unsigned __iomem *p);

#define fsl_readl(p)            (*_fsl_readl)((p))
#define fsl_writel(v, p)        (*_fsl_writel)((v), (p))

#else
#define fsl_readl(addr)         readl(addr)
#define fsl_writel(val, addr)   writel(val, addr)
#endif /* CONFIG_PPC32 */

int write_ulpi(u8 addr, u8 data)
{
        u32 temp;

        temp = 0x60000000 | (addr << 16) | data;
        fsl_writel(temp, &usb_dr_regs->ulpiview);
        return 0;
}

/* -------------------------------------------------------------*/
/* Operations that will be called from OTG Finite State Machine */

/* Charge vbus for vbus pulsing in SRP */
void fsl_otg_chrg_vbus(struct otg_fsm *fsm, int on)
{
        u32 tmp;

        tmp = fsl_readl(&usb_dr_regs->otgsc) & ~OTGSC_INTSTS_MASK;

        if (on)
                /* stop discharging, start charging */
                tmp = (tmp & ~OTGSC_CTRL_VBUS_DISCHARGE) |
                        OTGSC_CTRL_VBUS_CHARGE;
        else
                /* stop charging */
                tmp &= ~OTGSC_CTRL_VBUS_CHARGE;

        fsl_writel(tmp, &usb_dr_regs->otgsc);
}

/* Discharge vbus through a resistor to ground */
void fsl_otg_dischrg_vbus(int on)
{
        u32 tmp;

        tmp = fsl_readl(&usb_dr_regs->otgsc) & ~OTGSC_INTSTS_MASK;

        if (on)
                /* stop charging, start discharging */
                tmp = (tmp & ~OTGSC_CTRL_VBUS_CHARGE) |
                        OTGSC_CTRL_VBUS_DISCHARGE;
        else
                /* stop discharging */
                tmp &= ~OTGSC_CTRL_VBUS_DISCHARGE;

        fsl_writel(tmp, &usb_dr_regs->otgsc);
}

/* A-device driver vbus, controlled through PP bit in PORTSC */
void fsl_otg_drv_vbus(struct otg_fsm *fsm, int on)
{
        u32 tmp;

        if (on) {
                tmp = fsl_readl(&usb_dr_regs->portsc) & ~PORTSC_W1C_BITS;
                fsl_writel(tmp | PORTSC_PORT_POWER, &usb_dr_regs->portsc);
        } else {
                tmp = fsl_readl(&usb_dr_regs->portsc) &
                      ~PORTSC_W1C_BITS & ~PORTSC_PORT_POWER;
                fsl_writel(tmp, &usb_dr_regs->portsc);
        }
}

/*
 * Pull-up D+, signalling connect by periperal. Also used in
 * data-line pulsing in SRP
 */
void fsl_otg_loc_conn(struct otg_fsm *fsm, int on)
{
        u32 tmp;

        tmp = fsl_readl(&usb_dr_regs->otgsc) & ~OTGSC_INTSTS_MASK;

        if (on)
                tmp |= OTGSC_CTRL_DATA_PULSING;
        else
                tmp &= ~OTGSC_CTRL_DATA_PULSING;

        fsl_writel(tmp, &usb_dr_regs->otgsc);
}

/*
 * Generate SOF by host.  This is controlled through suspend/resume the
 * port.  In host mode, controller will automatically send SOF.
 * Suspend will block the data on the port.
 */
void fsl_otg_loc_sof(struct otg_fsm *fsm, int on)
{
        u32 tmp;

        tmp = fsl_readl(&fsl_otg_dev->dr_mem_map->portsc) & ~PORTSC_W1C_BITS;
        if (on)
                tmp |= PORTSC_PORT_FORCE_RESUME;
        else
                tmp |= PORTSC_PORT_SUSPEND;

        fsl_writel(tmp, &fsl_otg_dev->dr_mem_map->portsc);

}

/* Start SRP pulsing by data-line pulsing, followed with v-bus pulsing. */
void fsl_otg_start_pulse(struct otg_fsm *fsm)
{
        u32 tmp;

        srp_wait_done = 0;
#ifdef HA_DATA_PULSE
        tmp = fsl_readl(&usb_dr_regs->otgsc) & ~OTGSC_INTSTS_MASK;
        tmp |= OTGSC_HA_DATA_PULSE;
        fsl_writel(tmp, &usb_dr_regs->otgsc);
#else
        fsl_otg_loc_conn(1);
#endif

        fsl_otg_add_timer(fsm, b_data_pulse_tmr);
}

void b_data_pulse_end(unsigned long foo)
{
#ifdef HA_DATA_PULSE
#else
        fsl_otg_loc_conn(0);
#endif

        /* Do VBUS pulse after data pulse */
        fsl_otg_pulse_vbus();
}

void fsl_otg_pulse_vbus(void)
{
        srp_wait_done = 0;
        fsl_otg_chrg_vbus(&fsl_otg_dev->fsm, 1);
        /* start the timer to end vbus charge */
        fsl_otg_add_timer(&fsl_otg_dev->fsm, b_vbus_pulse_tmr);
}

void b_vbus_pulse_end(unsigned long foo)
{
        fsl_otg_chrg_vbus(&fsl_otg_dev->fsm, 0);

        /*
         * As USB3300 using the same a_sess_vld and b_sess_vld voltage
         * we need to discharge the bus for a while to distinguish
         * residual voltage of vbus pulsing and A device pull up
         */
        fsl_otg_dischrg_vbus(1);
        fsl_otg_add_timer(&fsl_otg_dev->fsm, b_srp_wait_tmr);
}

void b_srp_end(unsigned long foo)
{
        fsl_otg_dischrg_vbus(0);
        srp_wait_done = 1;

        if ((fsl_otg_dev->phy.otg->state == OTG_STATE_B_SRP_INIT) &&
            fsl_otg_dev->fsm.b_sess_vld)
                fsl_otg_dev->fsm.b_srp_done = 1;
}

/*
 * Workaround for a_host suspending too fast.  When a_bus_req=0,
 * a_host will start by SRP.  It needs to set b_hnp_enable before
 * actually suspending to start HNP
 */
void a_wait_enum(unsigned long foo)
{
        VDBG("a_wait_enum timeout\n");
        if (!fsl_otg_dev->phy.otg->host->b_hnp_enable)
                fsl_otg_add_timer(&fsl_otg_dev->fsm, a_wait_enum_tmr);
        else
                otg_statemachine(&fsl_otg_dev->fsm);
}

/* The timeout callback function to set time out bit */
void set_tmout(unsigned long indicator)
{
        *(int *)indicator = 1;
}

/* Initialize timers */
int fsl_otg_init_timers(struct otg_fsm *fsm)
{
        /* FSM used timers */
        a_wait_vrise_tmr = otg_timer_initializer(&set_tmout, TA_WAIT_VRISE,
                                (unsigned long)&fsm->a_wait_vrise_tmout);
        if (!a_wait_vrise_tmr)
                return -ENOMEM;

        a_wait_bcon_tmr = otg_timer_initializer(&set_tmout, TA_WAIT_BCON,
                                (unsigned long)&fsm->a_wait_bcon_tmout);
        if (!a_wait_bcon_tmr)
                return -ENOMEM;

        a_aidl_bdis_tmr = otg_timer_initializer(&set_tmout, TA_AIDL_BDIS,
                                (unsigned long)&fsm->a_aidl_bdis_tmout);
        if (!a_aidl_bdis_tmr)
                return -ENOMEM;

        b_ase0_brst_tmr = otg_timer_initializer(&set_tmout, TB_ASE0_BRST,
                                (unsigned long)&fsm->b_ase0_brst_tmout);
        if (!b_ase0_brst_tmr)
                return -ENOMEM;

        b_se0_srp_tmr = otg_timer_initializer(&set_tmout, TB_SE0_SRP,
                                (unsigned long)&fsm->b_se0_srp);
        if (!b_se0_srp_tmr)
                return -ENOMEM;

        b_srp_fail_tmr = otg_timer_initializer(&set_tmout, TB_SRP_FAIL,
                                (unsigned long)&fsm->b_srp_done);
        if (!b_srp_fail_tmr)
                return -ENOMEM;

        a_wait_enum_tmr = otg_timer_initializer(&a_wait_enum, 10,
                                (unsigned long)&fsm);
        if (!a_wait_enum_tmr)
                return -ENOMEM;

        /* device driver used timers */
        b_srp_wait_tmr = otg_timer_initializer(&b_srp_end, TB_SRP_WAIT, 0);
        if (!b_srp_wait_tmr)
                return -ENOMEM;

        b_data_pulse_tmr = otg_timer_initializer(&b_data_pulse_end,
                                TB_DATA_PLS, 0);
        if (!b_data_pulse_tmr)
                return -ENOMEM;

        b_vbus_pulse_tmr = otg_timer_initializer(&b_vbus_pulse_end,
                                TB_VBUS_PLS, 0);
        if (!b_vbus_pulse_tmr)
                return -ENOMEM;

        return 0;
}

/* Uninitialize timers */
void fsl_otg_uninit_timers(void)
{
        /* FSM used timers */
        kfree(a_wait_vrise_tmr);
        kfree(a_wait_bcon_tmr);
        kfree(a_aidl_bdis_tmr);
        kfree(b_ase0_brst_tmr);
        kfree(b_se0_srp_tmr);
        kfree(b_srp_fail_tmr);
        kfree(a_wait_enum_tmr);

        /* device driver used timers */
        kfree(b_srp_wait_tmr);
        kfree(b_data_pulse_tmr);
        kfree(b_vbus_pulse_tmr);
}

static struct fsl_otg_timer *fsl_otg_get_timer(enum otg_fsm_timer t)
{
        struct fsl_otg_timer *timer;

        /* REVISIT: use array of pointers to timers instead */
        switch (t) {
        case A_WAIT_VRISE:
                timer = a_wait_vrise_tmr;
                break;
        case A_WAIT_BCON:
                timer = a_wait_vrise_tmr;
                break;
        case A_AIDL_BDIS:
                timer = a_wait_vrise_tmr;
                break;
        case B_ASE0_BRST:
                timer = a_wait_vrise_tmr;
                break;
        case B_SE0_SRP:
                timer = a_wait_vrise_tmr;
                break;
        case B_SRP_FAIL:
                timer = a_wait_vrise_tmr;
                break;
        case A_WAIT_ENUM:
                timer = a_wait_vrise_tmr;
                break;
        default:
                timer = NULL;
        }

        return timer;
}

/* Add timer to timer list */
void fsl_otg_add_timer(struct otg_fsm *fsm, void *gtimer)
{
        struct fsl_otg_timer *timer = gtimer;
        struct fsl_otg_timer *tmp_timer;

        /*
         * Check if the timer is already in the active list,
         * if so update timer count
         */
        list_for_each_entry(tmp_timer, &active_timers, list)
            if (tmp_timer == timer) {
                timer->count = timer->expires;
                return;
        }
        timer->count = timer->expires;
        list_add_tail(&timer->list, &active_timers);
}

static void fsl_otg_fsm_add_timer(struct otg_fsm *fsm, enum otg_fsm_timer t)
{
        struct fsl_otg_timer *timer;

        timer = fsl_otg_get_timer(t);
        if (!timer)
                return;

        fsl_otg_add_timer(fsm, timer);
}

/* Remove timer from the timer list; clear timeout status */
void fsl_otg_del_timer(struct otg_fsm *fsm, void *gtimer)
{
        struct fsl_otg_timer *timer = gtimer;
        struct fsl_otg_timer *tmp_timer, *del_tmp;

        list_for_each_entry_safe(tmp_timer, del_tmp, &active_timers, list)
                if (tmp_timer == timer)
                        list_del(&timer->list);
}

static void fsl_otg_fsm_del_timer(struct otg_fsm *fsm, enum otg_fsm_timer t)
{
        struct fsl_otg_timer *timer;

        timer = fsl_otg_get_timer(t);
        if (!timer)
                return;

        fsl_otg_del_timer(fsm, timer);
}

/* Reset controller, not reset the bus */
void otg_reset_controller(void)
{
        u32 command;

        command = fsl_readl(&usb_dr_regs->usbcmd);
        command |= (1 << 1);
        fsl_writel(command, &usb_dr_regs->usbcmd);
        while (fsl_readl(&usb_dr_regs->usbcmd) & (1 << 1))
                ;
}

/* Call suspend/resume routines in host driver */
int fsl_otg_start_host(struct otg_fsm *fsm, int on)
{
        struct usb_otg *otg = fsm->otg;
        struct device *dev;
        struct fsl_otg *otg_dev =
                container_of(otg->usb_phy, struct fsl_otg, phy);
        u32 retval = 0;

        if (!otg->host)
                return -ENODEV;
        dev = otg->host->controller;

        /*
         * Update a_vbus_vld state as a_vbus_vld int is disabled
         * in device mode
         */
        fsm->a_vbus_vld =
                !!(fsl_readl(&usb_dr_regs->otgsc) & OTGSC_STS_A_VBUS_VALID);
        if (on) {
                /* start fsl usb host controller */
                if (otg_dev->host_working)
                        goto end;
                else {
                        otg_reset_controller();
                        VDBG("host on......\n");
                        if (dev->driver->pm && dev->driver->pm->resume) {
                                retval = dev->driver->pm->resume(dev);
                                if (fsm->id) {
                                        /* default-b */
                                        fsl_otg_drv_vbus(fsm, 1);
                                        /*
                                         * Workaround: b_host can't driver
                                         * vbus, but PP in PORTSC needs to
                                         * be 1 for host to work.
                                         * So we set drv_vbus bit in
                                         * transceiver to 0 thru ULPI.
                                         */
                                        write_ulpi(0x0c, 0x20);
                                }
                        }

                        otg_dev->host_working = 1;
                }
        } else {
                /* stop fsl usb host controller */
                if (!otg_dev->host_working)
                        goto end;
                else {
                        VDBG("host off......\n");
                        if (dev && dev->driver) {
                                if (dev->driver->pm && dev->driver->pm->suspend)
                                        retval = dev->driver->pm->suspend(dev);
                                if (fsm->id)
                                        /* default-b */
                                        fsl_otg_drv_vbus(fsm, 0);
                        }
                        otg_dev->host_working = 0;
                }
        }
end:
        return retval;
}

/*
 * Call suspend and resume function in udc driver
 * to stop and start udc driver.
 */
int fsl_otg_start_gadget(struct otg_fsm *fsm, int on)
{
        struct usb_otg *otg = fsm->otg;
        struct device *dev;

        if (!otg->gadget || !otg->gadget->dev.parent)
                return -ENODEV;

        VDBG("gadget %s\n", on ? "on" : "off");
        dev = otg->gadget->dev.parent;

        if (on) {
                if (dev->driver->resume)
                        dev->driver->resume(dev);
        } else {
                if (dev->driver->suspend)
                        dev->driver->suspend(dev, otg_suspend_state);
        }

        return 0;
}

/*
 * Called by initialization code of host driver.  Register host controller
 * to the OTG.  Suspend host for OTG role detection.
 */
static int fsl_otg_set_host(struct usb_otg *otg, struct usb_bus *host)
{
        struct fsl_otg *otg_dev;

        if (!otg)
                return -ENODEV;

        otg_dev = container_of(otg->usb_phy, struct fsl_otg, phy);
        if (otg_dev != fsl_otg_dev)
                return -ENODEV;

        otg->host = host;

        otg_dev->fsm.a_bus_drop = 0;
        otg_dev->fsm.a_bus_req = 1;

        if (host) {
                VDBG("host off......\n");

                otg->host->otg_port = fsl_otg_initdata.otg_port;
                otg->host->is_b_host = otg_dev->fsm.id;
                /*
                 * must leave time for hub_wq to finish its thing
                 * before yanking the host driver out from under it,
                 * so suspend the host after a short delay.
                 */
                otg_dev->host_working = 1;
                schedule_delayed_work(&otg_dev->otg_event, 100);
                return 0;
        } else {
                /* host driver going away */
                if (!(fsl_readl(&otg_dev->dr_mem_map->otgsc) &
                      OTGSC_STS_USB_ID)) {
                        /* Mini-A cable connected */
                        struct otg_fsm *fsm = &otg_dev->fsm;

                        otg->state = OTG_STATE_UNDEFINED;
                        fsm->protocol = PROTO_UNDEF;
                }
        }

        otg_dev->host_working = 0;

        otg_statemachine(&otg_dev->fsm);

        return 0;
}

/* Called by initialization code of udc.  Register udc to OTG. */
static int fsl_otg_set_peripheral(struct usb_otg *otg,
                                        struct usb_gadget *gadget)
{
        struct fsl_otg *otg_dev;

        if (!otg)
                return -ENODEV;

        otg_dev = container_of(otg->usb_phy, struct fsl_otg, phy);
        VDBG("otg_dev 0x%x\n", (int)otg_dev);
        VDBG("fsl_otg_dev 0x%x\n", (int)fsl_otg_dev);
        if (otg_dev != fsl_otg_dev)
                return -ENODEV;

        if (!gadget) {
                if (!otg->default_a)
                        otg->gadget->ops->vbus_draw(otg->gadget, 0);
                usb_gadget_vbus_disconnect(otg->gadget);
                otg->gadget = 0;
                otg_dev->fsm.b_bus_req = 0;
                otg_statemachine(&otg_dev->fsm);
                return 0;
        }

        otg->gadget = gadget;
        otg->gadget->is_a_peripheral = !otg_dev->fsm.id;

        otg_dev->fsm.b_bus_req = 1;

        /* start the gadget right away if the ID pin says Mini-B */
        pr_debug("ID pin=%d\n", otg_dev->fsm.id);
        if (otg_dev->fsm.id == 1) {
                fsl_otg_start_host(&otg_dev->fsm, 0);
                otg_drv_vbus(&otg_dev->fsm, 0);
                fsl_otg_start_gadget(&otg_dev->fsm, 1);
        }

        return 0;
}

/* Set OTG port power, only for B-device */
static int fsl_otg_set_power(struct usb_phy *phy, unsigned mA)
{
        if (!fsl_otg_dev)
                return -ENODEV;
        if (phy->otg->state == OTG_STATE_B_PERIPHERAL)
                pr_info("FSL OTG: Draw %d mA\n", mA);

        return 0;
}

/*
 * Delayed pin detect interrupt processing.
 *
 * When the Mini-A cable is disconnected from the board,
 * the pin-detect interrupt happens before the disconnect
 * interrupts for the connected device(s).  In order to
 * process the disconnect interrupt(s) prior to switching
 * roles, the pin-detect interrupts are delayed, and handled
 * by this routine.
 */
static void fsl_otg_event(struct work_struct *work)
{
        struct fsl_otg *og = container_of(work, struct fsl_otg, otg_event.work);
        struct otg_fsm *fsm = &og->fsm;

        if (fsm->id) {          /* switch to gadget */
                fsl_otg_start_host(fsm, 0);
                otg_drv_vbus(fsm, 0);
                fsl_otg_start_gadget(fsm, 1);
        }
}

/* B-device start SRP */
static int fsl_otg_start_srp(struct usb_otg *otg)
{
        struct fsl_otg *otg_dev;

        if (!otg || otg->state != OTG_STATE_B_IDLE)
                return -ENODEV;

        otg_dev = container_of(otg->usb_phy, struct fsl_otg, phy);
        if (otg_dev != fsl_otg_dev)
                return -ENODEV;

        otg_dev->fsm.b_bus_req = 1;
        otg_statemachine(&otg_dev->fsm);

        return 0;
}

/* A_host suspend will call this function to start hnp */
static int fsl_otg_start_hnp(struct usb_otg *otg)
{
        struct fsl_otg *otg_dev;

        if (!otg)
                return -ENODEV;

        otg_dev = container_of(otg->usb_phy, struct fsl_otg, phy);
        if (otg_dev != fsl_otg_dev)
                return -ENODEV;

        pr_debug("start_hnp...\n");

        /* clear a_bus_req to enter a_suspend state */
        otg_dev->fsm.a_bus_req = 0;
        otg_statemachine(&otg_dev->fsm);

        return 0;
}

/*
 * Interrupt handler.  OTG/host/peripheral share the same int line.
 * OTG driver clears OTGSC interrupts and leaves USB interrupts
 * intact.  It needs to have knowledge of some USB interrupts
 * such as port change.
 */
irqreturn_t fsl_otg_isr(int irq, void *dev_id)
{
        struct otg_fsm *fsm = &((struct fsl_otg *)dev_id)->fsm;
        struct usb_otg *otg = ((struct fsl_otg *)dev_id)->phy.otg;
        u32 otg_int_src, otg_sc;

        otg_sc = fsl_readl(&usb_dr_regs->otgsc);
        otg_int_src = otg_sc & OTGSC_INTSTS_MASK & (otg_sc >> 8);

        /* Only clear otg interrupts */
        fsl_writel(otg_sc, &usb_dr_regs->otgsc);

        /*FIXME: ID change not generate when init to 0 */
        fsm->id = (otg_sc & OTGSC_STS_USB_ID) ? 1 : 0;
        otg->default_a = (fsm->id == 0);

        /* process OTG interrupts */
        if (otg_int_src) {
                if (otg_int_src & OTGSC_INTSTS_USB_ID) {
                        fsm->id = (otg_sc & OTGSC_STS_USB_ID) ? 1 : 0;
                        otg->default_a = (fsm->id == 0);
                        /* clear conn information */
                        if (fsm->id)
                                fsm->b_conn = 0;
                        else
                                fsm->a_conn = 0;

                        if (otg->host)
                                otg->host->is_b_host = fsm->id;
                        if (otg->gadget)
                                otg->gadget->is_a_peripheral = !fsm->id;
                        VDBG("ID int (ID is %d)\n", fsm->id);

                        if (fsm->id) {  /* switch to gadget */
                                schedule_delayed_work(
                                        &((struct fsl_otg *)dev_id)->otg_event,
                                        100);
                        } else {        /* switch to host */
                                cancel_delayed_work(&
                                                    ((struct fsl_otg *)dev_id)->
                                                    otg_event);
                                fsl_otg_start_gadget(fsm, 0);
                                otg_drv_vbus(fsm, 1);
                                fsl_otg_start_host(fsm, 1);
                        }
                        return IRQ_HANDLED;
                }
        }
        return IRQ_NONE;
}

static struct otg_fsm_ops fsl_otg_ops = {
        .chrg_vbus = fsl_otg_chrg_vbus,
        .drv_vbus = fsl_otg_drv_vbus,
        .loc_conn = fsl_otg_loc_conn,
        .loc_sof = fsl_otg_loc_sof,
        .start_pulse = fsl_otg_start_pulse,

        .add_timer = fsl_otg_fsm_add_timer,
        .del_timer = fsl_otg_fsm_del_timer,

        .start_host = fsl_otg_start_host,
        .start_gadget = fsl_otg_start_gadget,
};

/* Initialize the global variable fsl_otg_dev and request IRQ for OTG */
static int fsl_otg_conf(struct platform_device *pdev)
{
        struct fsl_otg *fsl_otg_tc;
        int status;

        if (fsl_otg_dev)
                return 0;

        /* allocate space to fsl otg device */
        fsl_otg_tc = kzalloc(sizeof(struct fsl_otg), GFP_KERNEL);
        if (!fsl_otg_tc)
                return -ENOMEM;

        fsl_otg_tc->phy.otg = kzalloc(sizeof(struct usb_otg), GFP_KERNEL);
        if (!fsl_otg_tc->phy.otg) {
                kfree(fsl_otg_tc);
                return -ENOMEM;
        }

        INIT_DELAYED_WORK(&fsl_otg_tc->otg_event, fsl_otg_event);

        INIT_LIST_HEAD(&active_timers);
        status = fsl_otg_init_timers(&fsl_otg_tc->fsm);
        if (status) {
                pr_info("Couldn't init OTG timers\n");
                goto err;
        }
        mutex_init(&fsl_otg_tc->fsm.lock);

        /* Set OTG state machine operations */
        fsl_otg_tc->fsm.ops = &fsl_otg_ops;

        /* initialize the otg structure */
        fsl_otg_tc->phy.label = DRIVER_DESC;
        fsl_otg_tc->phy.dev = &pdev->dev;
        fsl_otg_tc->phy.set_power = fsl_otg_set_power;

        fsl_otg_tc->phy.otg->usb_phy = &fsl_otg_tc->phy;
        fsl_otg_tc->phy.otg->set_host = fsl_otg_set_host;
        fsl_otg_tc->phy.otg->set_peripheral = fsl_otg_set_peripheral;
        fsl_otg_tc->phy.otg->start_hnp = fsl_otg_start_hnp;
        fsl_otg_tc->phy.otg->start_srp = fsl_otg_start_srp;

        fsl_otg_dev = fsl_otg_tc;

        /* Store the otg transceiver */
        status = usb_add_phy(&fsl_otg_tc->phy, USB_PHY_TYPE_USB2);
        if (status) {
                pr_warn(FSL_OTG_NAME ": unable to register OTG transceiver.\n");
                goto err;
        }

        return 0;
err:
        fsl_otg_uninit_timers();
        kfree(fsl_otg_tc->phy.otg);
        kfree(fsl_otg_tc);
        return status;
}

/* OTG Initialization */
int usb_otg_start(struct platform_device *pdev)
{
        struct fsl_otg *p_otg;
        struct usb_phy *otg_trans = usb_get_phy(USB_PHY_TYPE_USB2);
        struct otg_fsm *fsm;
        int status;
        struct resource *res;
        u32 temp;
        struct fsl_usb2_platform_data *pdata = dev_get_platdata(&pdev->dev);

        p_otg = container_of(otg_trans, struct fsl_otg, phy);
        fsm = &p_otg->fsm;

        /* Initialize the state machine structure with default values */
        SET_OTG_STATE(otg_trans, OTG_STATE_UNDEFINED);
        fsm->otg = p_otg->phy.otg;

        /* We don't require predefined MEM/IRQ resource index */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res)
                return -ENXIO;

        /* We don't request_mem_region here to enable resource sharing
         * with host/device */

        usb_dr_regs = ioremap(res->start, sizeof(struct usb_dr_mmap));
        p_otg->dr_mem_map = (struct usb_dr_mmap *)usb_dr_regs;
        pdata->regs = (void *)usb_dr_regs;

        if (pdata->init && pdata->init(pdev) != 0)
                return -EINVAL;

        if (pdata->big_endian_mmio) {
                _fsl_readl = _fsl_readl_be;
                _fsl_writel = _fsl_writel_be;
        } else {
                _fsl_readl = _fsl_readl_le;
                _fsl_writel = _fsl_writel_le;
        }

        /* request irq */
        p_otg->irq = platform_get_irq(pdev, 0);
        status = request_irq(p_otg->irq, fsl_otg_isr,
                                IRQF_SHARED, driver_name, p_otg);
        if (status) {
                dev_dbg(p_otg->phy.dev, "can't get IRQ %d, error %d\n",
                        p_otg->irq, status);
                iounmap(p_otg->dr_mem_map);
                kfree(p_otg->phy.otg);
                kfree(p_otg);
                return status;
        }

        /* stop the controller */
        temp = fsl_readl(&p_otg->dr_mem_map->usbcmd);
        temp &= ~USB_CMD_RUN_STOP;
        fsl_writel(temp, &p_otg->dr_mem_map->usbcmd);

        /* reset the controller */
        temp = fsl_readl(&p_otg->dr_mem_map->usbcmd);
        temp |= USB_CMD_CTRL_RESET;
        fsl_writel(temp, &p_otg->dr_mem_map->usbcmd);

        /* wait reset completed */
        while (fsl_readl(&p_otg->dr_mem_map->usbcmd) & USB_CMD_CTRL_RESET)
                ;

        /* configure the VBUSHS as IDLE(both host and device) */
        temp = USB_MODE_STREAM_DISABLE | (pdata->es ? USB_MODE_ES : 0);
        fsl_writel(temp, &p_otg->dr_mem_map->usbmode);

        /* configure PHY interface */
        temp = fsl_readl(&p_otg->dr_mem_map->portsc);
        temp &= ~(PORTSC_PHY_TYPE_SEL | PORTSC_PTW);
        switch (pdata->phy_mode) {
        case FSL_USB2_PHY_ULPI:
                temp |= PORTSC_PTS_ULPI;
                break;
        case FSL_USB2_PHY_UTMI_WIDE:
                temp |= PORTSC_PTW_16BIT;
                /* fall through */
        case FSL_USB2_PHY_UTMI:
                temp |= PORTSC_PTS_UTMI;
                /* fall through */
        default:
                break;
        }
        fsl_writel(temp, &p_otg->dr_mem_map->portsc);

        if (pdata->have_sysif_regs) {
                /* configure control enable IO output, big endian register */
                temp = __raw_readl(&p_otg->dr_mem_map->control);
                temp |= USB_CTRL_IOENB;
                __raw_writel(temp, &p_otg->dr_mem_map->control);
        }

        /* disable all interrupt and clear all OTGSC status */
        temp = fsl_readl(&p_otg->dr_mem_map->otgsc);
        temp &= ~OTGSC_INTERRUPT_ENABLE_BITS_MASK;
        temp |= OTGSC_INTERRUPT_STATUS_BITS_MASK | OTGSC_CTRL_VBUS_DISCHARGE;
        fsl_writel(temp, &p_otg->dr_mem_map->otgsc);

        /*
         * The identification (id) input is FALSE when a Mini-A plug is inserted
         * in the devices Mini-AB receptacle. Otherwise, this input is TRUE.
         * Also: record initial state of ID pin
         */
        if (fsl_readl(&p_otg->dr_mem_map->otgsc) & OTGSC_STS_USB_ID) {
                p_otg->phy.otg->state = OTG_STATE_UNDEFINED;
                p_otg->fsm.id = 1;
        } else {
                p_otg->phy.otg->state = OTG_STATE_A_IDLE;
                p_otg->fsm.id = 0;
        }

        pr_debug("initial ID pin=%d\n", p_otg->fsm.id);

        /* enable OTG ID pin interrupt */
        temp = fsl_readl(&p_otg->dr_mem_map->otgsc);
        temp |= OTGSC_INTR_USB_ID_EN;
        temp &= ~(OTGSC_CTRL_VBUS_DISCHARGE | OTGSC_INTR_1MS_TIMER_EN);
        fsl_writel(temp, &p_otg->dr_mem_map->otgsc);

        return 0;
}

/*
 * state file in sysfs
 */
static int show_fsl_usb2_otg_state(struct device *dev,
                                   struct device_attribute *attr, char *buf)
{
        struct otg_fsm *fsm = &fsl_otg_dev->fsm;
        char *next = buf;
        unsigned size = PAGE_SIZE;
        int t;

        mutex_lock(&fsm->lock);

        /* basic driver infomation */
        t = scnprintf(next, size,
                        DRIVER_DESC "\n" "fsl_usb2_otg version: %s\n\n",
                        DRIVER_VERSION);
        size -= t;
        next += t;

        /* Registers */
        t = scnprintf(next, size,
                        "OTGSC:   0x%08x\n"
                        "PORTSC:  0x%08x\n"
                        "USBMODE: 0x%08x\n"
                        "USBCMD:  0x%08x\n"
                        "USBSTS:  0x%08x\n"
                        "USBINTR: 0x%08x\n",
                        fsl_readl(&usb_dr_regs->otgsc),
                        fsl_readl(&usb_dr_regs->portsc),
                        fsl_readl(&usb_dr_regs->usbmode),
                        fsl_readl(&usb_dr_regs->usbcmd),
                        fsl_readl(&usb_dr_regs->usbsts),
                        fsl_readl(&usb_dr_regs->usbintr));
        size -= t;
        next += t;

        /* State */
        t = scnprintf(next, size,
                      "OTG state: %s\n\n",
                      usb_otg_state_string(fsl_otg_dev->phy.otg->state));
        size -= t;
        next += t;

        /* State Machine Variables */
        t = scnprintf(next, size,
                        "a_bus_req: %d\n"
                        "b_bus_req: %d\n"
                        "a_bus_resume: %d\n"
                        "a_bus_suspend: %d\n"
                        "a_conn: %d\n"
                        "a_sess_vld: %d\n"
                        "a_srp_det: %d\n"
                        "a_vbus_vld: %d\n"
                        "b_bus_resume: %d\n"
                        "b_bus_suspend: %d\n"
                        "b_conn: %d\n"
                        "b_se0_srp: %d\n"
                        "b_ssend_srp: %d\n"
                        "b_sess_vld: %d\n"
                        "id: %d\n",
                        fsm->a_bus_req,
                        fsm->b_bus_req,
                        fsm->a_bus_resume,
                        fsm->a_bus_suspend,
                        fsm->a_conn,
                        fsm->a_sess_vld,
                        fsm->a_srp_det,
                        fsm->a_vbus_vld,
                        fsm->b_bus_resume,
                        fsm->b_bus_suspend,
                        fsm->b_conn,
                        fsm->b_se0_srp,
                        fsm->b_ssend_srp,
                        fsm->b_sess_vld,
                        fsm->id);
        size -= t;
        next += t;

        mutex_unlock(&fsm->lock);

        return PAGE_SIZE - size;
}

static DEVICE_ATTR(fsl_usb2_otg_state, S_IRUGO, show_fsl_usb2_otg_state, NULL);


/* Char driver interface to control some OTG input */

/*
 * Handle some ioctl command, such as get otg
 * status and set host suspend
 */
static long fsl_otg_ioctl(struct file *file, unsigned int cmd,
                          unsigned long arg)
{
        u32 retval = 0;

        switch (cmd) {
        case GET_OTG_STATUS:
                retval = fsl_otg_dev->host_working;
                break;

        case SET_A_SUSPEND_REQ:
                fsl_otg_dev->fsm.a_suspend_req_inf = arg;
                break;

        case SET_A_BUS_DROP:
                fsl_otg_dev->fsm.a_bus_drop = arg;
                break;

        case SET_A_BUS_REQ:
                fsl_otg_dev->fsm.a_bus_req = arg;
                break;

        case SET_B_BUS_REQ:
                fsl_otg_dev->fsm.b_bus_req = arg;
                break;

        default:
                break;
        }

        otg_statemachine(&fsl_otg_dev->fsm);

        return retval;
}

static int fsl_otg_open(struct inode *inode, struct file *file)
{
        return 0;
}

static int fsl_otg_release(struct inode *inode, struct file *file)
{
        return 0;
}

static const struct file_operations otg_fops = {
        .owner = THIS_MODULE,
        .llseek = NULL,
        .read = NULL,
        .write = NULL,
        .unlocked_ioctl = fsl_otg_ioctl,
        .open = fsl_otg_open,
        .release = fsl_otg_release,
};

static int fsl_otg_probe(struct platform_device *pdev)
{
        int ret;

        if (!dev_get_platdata(&pdev->dev))
                return -ENODEV;

        /* configure the OTG */
        ret = fsl_otg_conf(pdev);
        if (ret) {
                dev_err(&pdev->dev, "Couldn't configure OTG module\n");
                return ret;
        }

        /* start OTG */
        ret = usb_otg_start(pdev);
        if (ret) {
                dev_err(&pdev->dev, "Can't init FSL OTG device\n");
                return ret;
        }

        ret = register_chrdev(FSL_OTG_MAJOR, FSL_OTG_NAME, &otg_fops);
        if (ret) {
                dev_err(&pdev->dev, "unable to register FSL OTG device\n");
                return ret;
        }

        ret = device_create_file(&pdev->dev, &dev_attr_fsl_usb2_otg_state);
        if (ret)
                dev_warn(&pdev->dev, "Can't register sysfs attribute\n");

        return ret;
}

static int fsl_otg_remove(struct platform_device *pdev)
{
        struct fsl_usb2_platform_data *pdata = dev_get_platdata(&pdev->dev);

        usb_remove_phy(&fsl_otg_dev->phy);
        free_irq(fsl_otg_dev->irq, fsl_otg_dev);

        iounmap((void *)usb_dr_regs);

        fsl_otg_uninit_timers();
        kfree(fsl_otg_dev->phy.otg);
        kfree(fsl_otg_dev);

        device_remove_file(&pdev->dev, &dev_attr_fsl_usb2_otg_state);

        unregister_chrdev(FSL_OTG_MAJOR, FSL_OTG_NAME);

        if (pdata->exit)
                pdata->exit(pdev);

        return 0;
}

struct platform_driver fsl_otg_driver = {
        .probe = fsl_otg_probe,
        .remove = fsl_otg_remove,
        .driver = {
                .name = driver_name,
                .owner = THIS_MODULE,
        },
};

module_platform_driver(fsl_otg_driver);

MODULE_DESCRIPTION(DRIVER_INFO);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_LICENSE("GPL");