Linux 4.1.16

[linux/fpc-iii.git] / drivers / ata / ahci_xgene.c

/*
 * AppliedMicro X-Gene SoC SATA Host Controller Driver
 *
 * Copyright (c) 2014, Applied Micro Circuits Corporation
 * Author: Loc Ho <lho@apm.com>
 *         Tuan Phan <tphan@apm.com>
 *         Suman Tripathi <stripathi@apm.com>
 *
 * 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, see <http://www.gnu.org/licenses/>.
 *
 * NOTE: PM support is not currently available.
 *
 */
#include <linux/acpi.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/ahci_platform.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/phy/phy.h>
#include "ahci.h"

#define DRV_NAME "xgene-ahci"

/* Max # of disk per a controller */
#define MAX_AHCI_CHN_PERCTR             2

/* MUX CSR */
#define SATA_ENET_CONFIG_REG            0x00000000
#define  CFG_SATA_ENET_SELECT_MASK      0x00000001

/* SATA core host controller CSR */
#define SLVRDERRATTRIBUTES              0x00000000
#define SLVWRERRATTRIBUTES              0x00000004
#define MSTRDERRATTRIBUTES              0x00000008
#define MSTWRERRATTRIBUTES              0x0000000c
#define BUSCTLREG                       0x00000014
#define IOFMSTRWAUX                     0x00000018
#define INTSTATUSMASK                   0x0000002c
#define ERRINTSTATUS                    0x00000030
#define ERRINTSTATUSMASK                0x00000034

/* SATA host AHCI CSR */
#define PORTCFG                         0x000000a4
#define  PORTADDR_SET(dst, src) \
                (((dst) & ~0x0000003f) | (((u32)(src)) & 0x0000003f))
#define PORTPHY1CFG             0x000000a8
#define PORTPHY1CFG_FRCPHYRDY_SET(dst, src) \
                (((dst) & ~0x00100000) | (((u32)(src) << 0x14) & 0x00100000))
#define PORTPHY2CFG                     0x000000ac
#define PORTPHY3CFG                     0x000000b0
#define PORTPHY4CFG                     0x000000b4
#define PORTPHY5CFG                     0x000000b8
#define SCTL0                           0x0000012C
#define PORTPHY5CFG_RTCHG_SET(dst, src) \
                (((dst) & ~0xfff00000) | (((u32)(src) << 0x14) & 0xfff00000))
#define PORTAXICFG_EN_CONTEXT_SET(dst, src) \
                (((dst) & ~0x01000000) | (((u32)(src) << 0x18) & 0x01000000))
#define PORTAXICFG                      0x000000bc
#define PORTAXICFG_OUTTRANS_SET(dst, src) \
                (((dst) & ~0x00f00000) | (((u32)(src) << 0x14) & 0x00f00000))
#define PORTRANSCFG                     0x000000c8
#define PORTRANSCFG_RXWM_SET(dst, src)          \
                (((dst) & ~0x0000007f) | (((u32)(src)) & 0x0000007f))

/* SATA host controller AXI CSR */
#define INT_SLV_TMOMASK                 0x00000010

/* SATA diagnostic CSR */
#define CFG_MEM_RAM_SHUTDOWN            0x00000070
#define BLOCK_MEM_RDY                   0x00000074

/* Max retry for link down */
#define MAX_LINK_DOWN_RETRY 3

struct xgene_ahci_context {
        struct ahci_host_priv *hpriv;
        struct device *dev;
        u8 last_cmd[MAX_AHCI_CHN_PERCTR]; /* tracking the last command issued*/
        u32 class[MAX_AHCI_CHN_PERCTR]; /* tracking the class of device */
        void __iomem *csr_core;         /* Core CSR address of IP */
        void __iomem *csr_diag;         /* Diag CSR address of IP */
        void __iomem *csr_axi;          /* AXI CSR address of IP */
        void __iomem *csr_mux;          /* MUX CSR address of IP */
};

static int xgene_ahci_init_memram(struct xgene_ahci_context *ctx)
{
        dev_dbg(ctx->dev, "Release memory from shutdown\n");
        writel(0x0, ctx->csr_diag + CFG_MEM_RAM_SHUTDOWN);
        readl(ctx->csr_diag + CFG_MEM_RAM_SHUTDOWN); /* Force a barrier */
        msleep(1);      /* reset may take up to 1ms */
        if (readl(ctx->csr_diag + BLOCK_MEM_RDY) != 0xFFFFFFFF) {
                dev_err(ctx->dev, "failed to release memory from shutdown\n");
                return -ENODEV;
        }
        return 0;
}

/**
 * xgene_ahci_poll_reg_val- Poll a register on a specific value.
 * @ap : ATA port of interest.
 * @reg : Register of interest.
 * @val : Value to be attained.
 * @interval : waiting interval for polling.
 * @timeout : timeout for achieving the value.
 */
static int xgene_ahci_poll_reg_val(struct ata_port *ap,
                                   void __iomem *reg, unsigned
                                   int val, unsigned long interval,
                                   unsigned long timeout)
{
        unsigned long deadline;
        unsigned int tmp;

        tmp = ioread32(reg);
        deadline = ata_deadline(jiffies, timeout);

        while (tmp != val && time_before(jiffies, deadline)) {
                ata_msleep(ap, interval);
                tmp = ioread32(reg);
        }

        return tmp;
}

/**
 * xgene_ahci_restart_engine - Restart the dma engine.
 * @ap : ATA port of interest
 *
 * Waits for completion of multiple commands and restarts
 * the DMA engine inside the controller.
 */
static int xgene_ahci_restart_engine(struct ata_port *ap)
{
        struct ahci_host_priv *hpriv = ap->host->private_data;
        struct ahci_port_priv *pp = ap->private_data;
        void __iomem *port_mmio = ahci_port_base(ap);
        u32 fbs;

        /*
         * In case of PMP multiple IDENTIFY DEVICE commands can be
         * issued inside PxCI. So need to poll PxCI for the
         * completion of outstanding IDENTIFY DEVICE commands before
         * we restart the DMA engine.
         */
        if (xgene_ahci_poll_reg_val(ap, port_mmio +
                                    PORT_CMD_ISSUE, 0x0, 1, 100))
                  return -EBUSY;

        ahci_stop_engine(ap);
        ahci_start_fis_rx(ap);

        /*
         * Enable the PxFBS.FBS_EN bit as it
         * gets cleared due to stopping the engine.
         */
        if (pp->fbs_supported) {
                fbs = readl(port_mmio + PORT_FBS);
                writel(fbs | PORT_FBS_EN, port_mmio + PORT_FBS);
                fbs = readl(port_mmio + PORT_FBS);
        }

        hpriv->start_engine(ap);

        return 0;
}

/**
 * xgene_ahci_qc_issue - Issue commands to the device
 * @qc: Command to issue
 *
 * Due to Hardware errata for IDENTIFY DEVICE command, the controller cannot
 * clear the BSY bit after receiving the PIO setup FIS. This results in the dma
 * state machine goes into the CMFatalErrorUpdate state and locks up. By
 * restarting the dma engine, it removes the controller out of lock up state.
 *
 * Due to H/W errata, the controller is unable to save the PMP
 * field fetched from command header before sending the H2D FIS.
 * When the device returns the PMP port field in the D2H FIS, there is
 * a mismatch and results in command completion failure. The
 * workaround is to write the pmp value to PxFBS.DEV field before issuing
 * any command to PMP.
 */
static unsigned int xgene_ahci_qc_issue(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct ahci_host_priv *hpriv = ap->host->private_data;
        struct xgene_ahci_context *ctx = hpriv->plat_data;
        int rc = 0;
        u32 port_fbs;
        void *port_mmio = ahci_port_base(ap);

        /*
         * Write the pmp value to PxFBS.DEV
         * for case of Port Mulitplier.
         */
        if (ctx->class[ap->port_no] == ATA_DEV_PMP) {
                port_fbs = readl(port_mmio + PORT_FBS);
                port_fbs &= ~PORT_FBS_DEV_MASK;
                port_fbs |= qc->dev->link->pmp << PORT_FBS_DEV_OFFSET;
                writel(port_fbs, port_mmio + PORT_FBS);
        }

        if (unlikely((ctx->last_cmd[ap->port_no] == ATA_CMD_ID_ATA) ||
            (ctx->last_cmd[ap->port_no] == ATA_CMD_PACKET) ||
            (ctx->last_cmd[ap->port_no] == ATA_CMD_SMART)))
                xgene_ahci_restart_engine(ap);

        rc = ahci_qc_issue(qc);

        /* Save the last command issued */
        ctx->last_cmd[ap->port_no] = qc->tf.command;

        return rc;
}

static bool xgene_ahci_is_memram_inited(struct xgene_ahci_context *ctx)
{
        void __iomem *diagcsr = ctx->csr_diag;

        return (readl(diagcsr + CFG_MEM_RAM_SHUTDOWN) == 0 &&
                readl(diagcsr + BLOCK_MEM_RDY) == 0xFFFFFFFF);
}

/**
 * xgene_ahci_read_id - Read ID data from the specified device
 * @dev: device
 * @tf: proposed taskfile
 * @id: data buffer
 *
 * This custom read ID function is required due to the fact that the HW
 * does not support DEVSLP.
 */
static unsigned int xgene_ahci_read_id(struct ata_device *dev,
                                       struct ata_taskfile *tf, u16 *id)
{
        u32 err_mask;

        err_mask = ata_do_dev_read_id(dev, tf, id);
        if (err_mask)
                return err_mask;

        /*
         * Mask reserved area. Word78 spec of Link Power Management
         * bit15-8: reserved
         * bit7: NCQ autosence
         * bit6: Software settings preservation supported
         * bit5: reserved
         * bit4: In-order sata delivery supported
         * bit3: DIPM requests supported
         * bit2: DMA Setup FIS Auto-Activate optimization supported
         * bit1: DMA Setup FIX non-Zero buffer offsets supported
         * bit0: Reserved
         *
         * Clear reserved bit 8 (DEVSLP bit) as we don't support DEVSLP
         */
        id[ATA_ID_FEATURE_SUPP] &= cpu_to_le16(~(1 << 8));

        return 0;
}

static void xgene_ahci_set_phy_cfg(struct xgene_ahci_context *ctx, int channel)
{
        void __iomem *mmio = ctx->hpriv->mmio;
        u32 val;

        dev_dbg(ctx->dev, "port configure mmio 0x%p channel %d\n",
                mmio, channel);
        val = readl(mmio + PORTCFG);
        val = PORTADDR_SET(val, channel == 0 ? 2 : 3);
        writel(val, mmio + PORTCFG);
        readl(mmio + PORTCFG);  /* Force a barrier */
        /* Disable fix rate */
        writel(0x0001fffe, mmio + PORTPHY1CFG);
        readl(mmio + PORTPHY1CFG); /* Force a barrier */
        writel(0x28183219, mmio + PORTPHY2CFG);
        readl(mmio + PORTPHY2CFG); /* Force a barrier */
        writel(0x13081008, mmio + PORTPHY3CFG);
        readl(mmio + PORTPHY3CFG); /* Force a barrier */
        writel(0x00480815, mmio + PORTPHY4CFG);
        readl(mmio + PORTPHY4CFG); /* Force a barrier */
        /* Set window negotiation */
        val = readl(mmio + PORTPHY5CFG);
        val = PORTPHY5CFG_RTCHG_SET(val, 0x300);
        writel(val, mmio + PORTPHY5CFG);
        readl(mmio + PORTPHY5CFG); /* Force a barrier */
        val = readl(mmio + PORTAXICFG);
        val = PORTAXICFG_EN_CONTEXT_SET(val, 0x1); /* Enable context mgmt */
        val = PORTAXICFG_OUTTRANS_SET(val, 0xe); /* Set outstanding */
        writel(val, mmio + PORTAXICFG);
        readl(mmio + PORTAXICFG); /* Force a barrier */
        /* Set the watermark threshold of the receive FIFO */
        val = readl(mmio + PORTRANSCFG);
        val = PORTRANSCFG_RXWM_SET(val, 0x30);
        writel(val, mmio + PORTRANSCFG);
}

/**
 * xgene_ahci_do_hardreset - Issue the actual COMRESET
 * @link: link to reset
 * @deadline: deadline jiffies for the operation
 * @online: Return value to indicate if device online
 *
 * Due to the limitation of the hardware PHY, a difference set of setting is
 * required for each supported disk speed - Gen3 (6.0Gbps), Gen2 (3.0Gbps),
 * and Gen1 (1.5Gbps). Otherwise during long IO stress test, the PHY will
 * report disparity error and etc. In addition, during COMRESET, there can
 * be error reported in the register PORT_SCR_ERR. For SERR_DISPARITY and
 * SERR_10B_8B_ERR, the PHY receiver line must be reseted. Also during long
 * reboot cycle regression, sometimes the PHY reports link down even if the
 * device is present because of speed negotiation failure. so need to retry
 * the COMRESET to get the link up. The following algorithm is followed to
 * proper configure the hardware PHY during COMRESET:
 *
 * Alg Part 1:
 * 1. Start the PHY at Gen3 speed (default setting)
 * 2. Issue the COMRESET
 * 3. If no link, go to Alg Part 3
 * 4. If link up, determine if the negotiated speed matches the PHY
 *    configured speed
 * 5. If they matched, go to Alg Part 2
 * 6. If they do not matched and first time, configure the PHY for the linked
 *    up disk speed and repeat step 2
 * 7. Go to Alg Part 2
 *
 * Alg Part 2:
 * 1. On link up, if there are any SERR_DISPARITY and SERR_10B_8B_ERR error
 *    reported in the register PORT_SCR_ERR, then reset the PHY receiver line
 * 2. Go to Alg Part 4
 *
 * Alg Part 3:
 * 1. Check the PORT_SCR_STAT to see whether device presence detected but PHY
 *    communication establishment failed and maximum link down attempts are
 *    less than Max attempts 3 then goto Alg Part 1.
 * 2. Go to Alg Part 4.
 *
 * Alg Part 4:
 * 1. Clear any pending from register PORT_SCR_ERR.
 *
 * NOTE: For the initial version, we will NOT support Gen1/Gen2. In addition
 *       and until the underlying PHY supports an method to reset the receiver
 *       line, on detection of SERR_DISPARITY or SERR_10B_8B_ERR errors,
 *       an warning message will be printed.
 */
static int xgene_ahci_do_hardreset(struct ata_link *link,
                                   unsigned long deadline, bool *online)
{
        const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
        struct ata_port *ap = link->ap;
        struct ahci_host_priv *hpriv = ap->host->private_data;
        struct xgene_ahci_context *ctx = hpriv->plat_data;
        struct ahci_port_priv *pp = ap->private_data;
        u8 *d2h_fis = pp->rx_fis + RX_FIS_D2H_REG;
        void __iomem *port_mmio = ahci_port_base(ap);
        struct ata_taskfile tf;
        int link_down_retry = 0;
        int rc;
        u32 val, sstatus;

        do {
                /* clear D2H reception area to properly wait for D2H FIS */
                ata_tf_init(link->device, &tf);
                tf.command = ATA_BUSY;
                ata_tf_to_fis(&tf, 0, 0, d2h_fis);
                rc = sata_link_hardreset(link, timing, deadline, online,
                                 ahci_check_ready);
                if (*online) {
                        val = readl(port_mmio + PORT_SCR_ERR);
                        if (val & (SERR_DISPARITY | SERR_10B_8B_ERR))
                                dev_warn(ctx->dev, "link has error\n");
                        break;
                }

                sata_scr_read(link, SCR_STATUS, &sstatus);
        } while (link_down_retry++ < MAX_LINK_DOWN_RETRY &&
                 (sstatus & 0xff) == 0x1);

        /* clear all errors if any pending */
        val = readl(port_mmio + PORT_SCR_ERR);
        writel(val, port_mmio + PORT_SCR_ERR);

        return rc;
}

static int xgene_ahci_hardreset(struct ata_link *link, unsigned int *class,
                                unsigned long deadline)
{
        struct ata_port *ap = link->ap;
        struct ahci_host_priv *hpriv = ap->host->private_data;
        void __iomem *port_mmio = ahci_port_base(ap);
        bool online;
        int rc;
        u32 portcmd_saved;
        u32 portclb_saved;
        u32 portclbhi_saved;
        u32 portrxfis_saved;
        u32 portrxfishi_saved;

        /* As hardreset resets these CSR, save it to restore later */
        portcmd_saved = readl(port_mmio + PORT_CMD);
        portclb_saved = readl(port_mmio + PORT_LST_ADDR);
        portclbhi_saved = readl(port_mmio + PORT_LST_ADDR_HI);
        portrxfis_saved = readl(port_mmio + PORT_FIS_ADDR);
        portrxfishi_saved = readl(port_mmio + PORT_FIS_ADDR_HI);

        ahci_stop_engine(ap);

        rc = xgene_ahci_do_hardreset(link, deadline, &online);

        /* As controller hardreset clears them, restore them */
        writel(portcmd_saved, port_mmio + PORT_CMD);
        writel(portclb_saved, port_mmio + PORT_LST_ADDR);
        writel(portclbhi_saved, port_mmio + PORT_LST_ADDR_HI);
        writel(portrxfis_saved, port_mmio + PORT_FIS_ADDR);
        writel(portrxfishi_saved, port_mmio + PORT_FIS_ADDR_HI);

        hpriv->start_engine(ap);

        if (online)
                *class = ahci_dev_classify(ap);

        return rc;
}

static void xgene_ahci_host_stop(struct ata_host *host)
{
        struct ahci_host_priv *hpriv = host->private_data;

        ahci_platform_disable_resources(hpriv);
}

/**
 * xgene_ahci_pmp_softreset - Issue the softreset to the drives connected
 *                            to Port Multiplier.
 * @link: link to reset
 * @class: Return value to indicate class of device
 * @deadline: deadline jiffies for the operation
 *
 * Due to H/W errata, the controller is unable to save the PMP
 * field fetched from command header before sending the H2D FIS.
 * When the device returns the PMP port field in the D2H FIS, there is
 * a mismatch and results in command completion failure. The workaround
 * is to write the pmp value to PxFBS.DEV field before issuing any command
 * to PMP.
 */
static int xgene_ahci_pmp_softreset(struct ata_link *link, unsigned int *class,
                          unsigned long deadline)
{
        int pmp = sata_srst_pmp(link);
        struct ata_port *ap = link->ap;
        u32 rc;
        void *port_mmio = ahci_port_base(ap);
        u32 port_fbs;

        /*
         * Set PxFBS.DEV field with pmp
         * value.
         */
        port_fbs = readl(port_mmio + PORT_FBS);
        port_fbs &= ~PORT_FBS_DEV_MASK;
        port_fbs |= pmp << PORT_FBS_DEV_OFFSET;
        writel(port_fbs, port_mmio + PORT_FBS);

        rc = ahci_do_softreset(link, class, pmp, deadline, ahci_check_ready);

        return rc;
}

/**
 * xgene_ahci_softreset - Issue the softreset to the drive.
 * @link: link to reset
 * @class: Return value to indicate class of device
 * @deadline: deadline jiffies for the operation
 *
 * Due to H/W errata, the controller is unable to save the PMP
 * field fetched from command header before sending the H2D FIS.
 * When the device returns the PMP port field in the D2H FIS, there is
 * a mismatch and results in command completion failure. The workaround
 * is to write the pmp value to PxFBS.DEV field before issuing any command
 * to PMP. Here is the algorithm to detect PMP :
 *
 * 1. Save the PxFBS value
 * 2. Program PxFBS.DEV with pmp value send by framework. Framework sends
 *    0xF for both PMP/NON-PMP initially
 * 3. Issue softreset
 * 4. If signature class is PMP goto 6
 * 5. restore the original PxFBS and goto 3
 * 6. return
 */
static int xgene_ahci_softreset(struct ata_link *link, unsigned int *class,
                          unsigned long deadline)
{
        int pmp = sata_srst_pmp(link);
        struct ata_port *ap = link->ap;
        struct ahci_host_priv *hpriv = ap->host->private_data;
        struct xgene_ahci_context *ctx = hpriv->plat_data;
        void *port_mmio = ahci_port_base(ap);
        u32 port_fbs;
        u32 port_fbs_save;
        u32 retry = 1;
        u32 rc;

        port_fbs_save = readl(port_mmio + PORT_FBS);

        /*
         * Set PxFBS.DEV field with pmp
         * value.
         */
        port_fbs = readl(port_mmio + PORT_FBS);
        port_fbs &= ~PORT_FBS_DEV_MASK;
        port_fbs |= pmp << PORT_FBS_DEV_OFFSET;
        writel(port_fbs, port_mmio + PORT_FBS);

softreset_retry:
        rc = ahci_do_softreset(link, class, pmp,
                               deadline, ahci_check_ready);

        ctx->class[ap->port_no] = *class;
        if (*class != ATA_DEV_PMP) {
                /*
                 * Retry for normal drives without
                 * setting PxFBS.DEV field with pmp value.
                 */
                if (retry--) {
                        writel(port_fbs_save, port_mmio + PORT_FBS);
                        goto softreset_retry;
                }
        }

        return rc;
}

static struct ata_port_operations xgene_ahci_ops = {
        .inherits = &ahci_ops,
        .host_stop = xgene_ahci_host_stop,
        .hardreset = xgene_ahci_hardreset,
        .read_id = xgene_ahci_read_id,
        .qc_issue = xgene_ahci_qc_issue,
        .softreset = xgene_ahci_softreset,
        .pmp_softreset = xgene_ahci_pmp_softreset
};

static const struct ata_port_info xgene_ahci_port_info = {
        .flags = AHCI_FLAG_COMMON | ATA_FLAG_PMP,
        .pio_mask = ATA_PIO4,
        .udma_mask = ATA_UDMA6,
        .port_ops = &xgene_ahci_ops,
};

static int xgene_ahci_hw_init(struct ahci_host_priv *hpriv)
{
        struct xgene_ahci_context *ctx = hpriv->plat_data;
        int i;
        int rc;
        u32 val;

        /* Remove IP RAM out of shutdown */
        rc = xgene_ahci_init_memram(ctx);
        if (rc)
                return rc;

        for (i = 0; i < MAX_AHCI_CHN_PERCTR; i++)
                xgene_ahci_set_phy_cfg(ctx, i);

        /* AXI disable Mask */
        writel(0xffffffff, hpriv->mmio + HOST_IRQ_STAT);
        readl(hpriv->mmio + HOST_IRQ_STAT); /* Force a barrier */
        writel(0, ctx->csr_core + INTSTATUSMASK);
        val = readl(ctx->csr_core + INTSTATUSMASK); /* Force a barrier */
        dev_dbg(ctx->dev, "top level interrupt mask 0x%X value 0x%08X\n",
                INTSTATUSMASK, val);

        writel(0x0, ctx->csr_core + ERRINTSTATUSMASK);
        readl(ctx->csr_core + ERRINTSTATUSMASK); /* Force a barrier */
        writel(0x0, ctx->csr_axi + INT_SLV_TMOMASK);
        readl(ctx->csr_axi + INT_SLV_TMOMASK);

        /* Enable AXI Interrupt */
        writel(0xffffffff, ctx->csr_core + SLVRDERRATTRIBUTES);
        writel(0xffffffff, ctx->csr_core + SLVWRERRATTRIBUTES);
        writel(0xffffffff, ctx->csr_core + MSTRDERRATTRIBUTES);
        writel(0xffffffff, ctx->csr_core + MSTWRERRATTRIBUTES);

        /* Enable coherency */
        val = readl(ctx->csr_core + BUSCTLREG);
        val &= ~0x00000002;     /* Enable write coherency */
        val &= ~0x00000001;     /* Enable read coherency */
        writel(val, ctx->csr_core + BUSCTLREG);

        val = readl(ctx->csr_core + IOFMSTRWAUX);
        val |= (1 << 3);        /* Enable read coherency */
        val |= (1 << 9);        /* Enable write coherency */
        writel(val, ctx->csr_core + IOFMSTRWAUX);
        val = readl(ctx->csr_core + IOFMSTRWAUX);
        dev_dbg(ctx->dev, "coherency 0x%X value 0x%08X\n",
                IOFMSTRWAUX, val);

        return rc;
}

static int xgene_ahci_mux_select(struct xgene_ahci_context *ctx)
{
        u32 val;

        /* Check for optional MUX resource */
        if (!ctx->csr_mux)
                return 0;

        val = readl(ctx->csr_mux + SATA_ENET_CONFIG_REG);
        val &= ~CFG_SATA_ENET_SELECT_MASK;
        writel(val, ctx->csr_mux + SATA_ENET_CONFIG_REG);
        val = readl(ctx->csr_mux + SATA_ENET_CONFIG_REG);
        return val & CFG_SATA_ENET_SELECT_MASK ? -1 : 0;
}

static struct scsi_host_template ahci_platform_sht = {
        AHCI_SHT(DRV_NAME),
};

static int xgene_ahci_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct ahci_host_priv *hpriv;
        struct xgene_ahci_context *ctx;
        struct resource *res;
        int rc;

        hpriv = ahci_platform_get_resources(pdev);
        if (IS_ERR(hpriv))
                return PTR_ERR(hpriv);

        ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
        if (!ctx)
                return -ENOMEM;

        hpriv->plat_data = ctx;
        ctx->hpriv = hpriv;
        ctx->dev = dev;

        /* Retrieve the IP core resource */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
        ctx->csr_core = devm_ioremap_resource(dev, res);
        if (IS_ERR(ctx->csr_core))
                return PTR_ERR(ctx->csr_core);

        /* Retrieve the IP diagnostic resource */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
        ctx->csr_diag = devm_ioremap_resource(dev, res);
        if (IS_ERR(ctx->csr_diag))
                return PTR_ERR(ctx->csr_diag);

        /* Retrieve the IP AXI resource */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
        ctx->csr_axi = devm_ioremap_resource(dev, res);
        if (IS_ERR(ctx->csr_axi))
                return PTR_ERR(ctx->csr_axi);

        /* Retrieve the optional IP mux resource */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 4);
        if (res) {
                void __iomem *csr = devm_ioremap_resource(dev, res);
                if (IS_ERR(csr))
                        return PTR_ERR(csr);

                ctx->csr_mux = csr;
        }

        dev_dbg(dev, "VAddr 0x%p Mmio VAddr 0x%p\n", ctx->csr_core,
                hpriv->mmio);

        /* Select ATA */
        if ((rc = xgene_ahci_mux_select(ctx))) {
                dev_err(dev, "SATA mux selection failed error %d\n", rc);
                return -ENODEV;
        }

        if (xgene_ahci_is_memram_inited(ctx)) {
                dev_info(dev, "skip clock and PHY initialization\n");
                goto skip_clk_phy;
        }

        /* Due to errata, HW requires full toggle transition */
        rc = ahci_platform_enable_clks(hpriv);
        if (rc)
                goto disable_resources;
        ahci_platform_disable_clks(hpriv);

        rc = ahci_platform_enable_resources(hpriv);
        if (rc)
                goto disable_resources;

        /* Configure the host controller */
        xgene_ahci_hw_init(hpriv);
skip_clk_phy:
        hpriv->flags = AHCI_HFLAG_NO_PMP | AHCI_HFLAG_NO_NCQ;

        rc = ahci_platform_init_host(pdev, hpriv, &xgene_ahci_port_info,
                                     &ahci_platform_sht);
        if (rc)
                goto disable_resources;

        dev_dbg(dev, "X-Gene SATA host controller initialized\n");
        return 0;

disable_resources:
        ahci_platform_disable_resources(hpriv);
        return rc;
}

#ifdef CONFIG_ACPI
static const struct acpi_device_id xgene_ahci_acpi_match[] = {
        { "APMC0D0D", },
        { }
};
MODULE_DEVICE_TABLE(acpi, xgene_ahci_acpi_match);
#endif

static const struct of_device_id xgene_ahci_of_match[] = {
        {.compatible = "apm,xgene-ahci"},
        {},
};
MODULE_DEVICE_TABLE(of, xgene_ahci_of_match);

static struct platform_driver xgene_ahci_driver = {
        .probe = xgene_ahci_probe,
        .remove = ata_platform_remove_one,
        .driver = {
                .name = DRV_NAME,
                .of_match_table = xgene_ahci_of_match,
                .acpi_match_table = ACPI_PTR(xgene_ahci_acpi_match),
        },
};

module_platform_driver(xgene_ahci_driver);

MODULE_DESCRIPTION("APM X-Gene AHCI SATA driver");
MODULE_AUTHOR("Loc Ho <lho@apm.com>");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.4");