// SPDX-License-Identifier: GPL-2.0
/*
 * Texas Instruments DSPS platforms "glue layer"
 *
 * Copyright (C) 2012, by Texas Instruments
 *
 * Based on the am35x "glue layer" code.
 *
 * This file is part of the Inventra Controller Driver for Linux.
 *
 * musb_dsps.c will be a common file for all the TI DSPS platforms
 * such as dm64x, dm36x, dm35x, da8x, am35x and ti81x.
 * For now only ti81x is using this and in future davinci.c, am35x.c
 * da8xx.c would be merged to this file after testing.
 */

#include <linux/io.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/pm_runtime.h>
#include <linux/module.h>
#include <linux/usb/usb_phy_generic.h>
#include <linux/platform_data/usb-omap.h>
#include <linux/sizes.h>

#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/usb/of.h>

#include <linux/debugfs.h>

#include "musb_core.h"

static const struct of_device_id musb_dsps_of_match[];

/**
 * DSPS musb wrapper register offset.
 * FIXME: This should be expanded to have all the wrapper registers from TI DSPS
 * musb ips.
 */
struct dsps_musb_wrapper {
        u16     revision;
        u16     control;
        u16     status;
        u16     epintr_set;
        u16     epintr_clear;
        u16     epintr_status;
        u16     coreintr_set;
        u16     coreintr_clear;
        u16     coreintr_status;
        u16     phy_utmi;
        u16     mode;
        u16     tx_mode;
        u16     rx_mode;

        /* bit positions for control */
        unsigned        reset:5;

        /* bit positions for interrupt */
        unsigned        usb_shift:5;
        u32             usb_mask;
        u32             usb_bitmap;
        unsigned        drvvbus:5;

        unsigned        txep_shift:5;
        u32             txep_mask;
        u32             txep_bitmap;

        unsigned        rxep_shift:5;
        u32             rxep_mask;
        u32             rxep_bitmap;

        /* bit positions for phy_utmi */
        unsigned        otg_disable:5;

        /* bit positions for mode */
        unsigned        iddig:5;
        unsigned        iddig_mux:5;
        /* miscellaneous stuff */
        unsigned        poll_timeout;
};

/*
 * register shadow for suspend
 */
struct dsps_context {
        u32 control;
        u32 epintr;
        u32 coreintr;
        u32 phy_utmi;
        u32 mode;
        u32 tx_mode;
        u32 rx_mode;
};

/**
 * DSPS glue structure.
 */
struct dsps_glue {
        struct device *dev;
        struct platform_device *musb;   /* child musb pdev */
        const struct dsps_musb_wrapper *wrp; /* wrapper register offsets */
        int vbus_irq;                   /* optional vbus irq */
        unsigned long last_timer;    /* last timer data for each instance */
        bool sw_babble_enabled;
        void __iomem *usbss_base;

        struct dsps_context context;
        struct debugfs_regset32 regset;
        struct dentry *dbgfs_root;
};

static const struct debugfs_reg32 dsps_musb_regs[] = {
        { "revision",           0x00 },
        { "control",            0x14 },
        { "status",             0x18 },
        { "eoi",                0x24 },
        { "intr0_stat",         0x30 },
        { "intr1_stat",         0x34 },
        { "intr0_set",          0x38 },
        { "intr1_set",          0x3c },
        { "txmode",             0x70 },
        { "rxmode",             0x74 },
        { "autoreq",            0xd0 },
        { "srpfixtime",         0xd4 },
        { "tdown",              0xd8 },
        { "phy_utmi",           0xe0 },
        { "mode",               0xe8 },
};

static void dsps_mod_timer(struct dsps_glue *glue, int wait_ms)
{
        struct musb *musb = platform_get_drvdata(glue->musb);
        int wait;

        if (wait_ms < 0)
                wait = msecs_to_jiffies(glue->wrp->poll_timeout);
        else
                wait = msecs_to_jiffies(wait_ms);

        mod_timer(&musb->dev_timer, jiffies + wait);
}

/*
 * If no vbus irq from the PMIC is configured, we need to poll VBUS status.
 */
static void dsps_mod_timer_optional(struct dsps_glue *glue)
{
        if (glue->vbus_irq)
                return;

        dsps_mod_timer(glue, -1);
}

/* USBSS  / USB AM335x */
#define USBSS_IRQ_STATUS        0x28
#define USBSS_IRQ_ENABLER       0x2c
#define USBSS_IRQ_CLEARR        0x30

#define USBSS_IRQ_PD_COMP       (1 << 2)

/**
 * dsps_musb_enable - enable interrupts
 */
static void dsps_musb_enable(struct musb *musb)
{
        struct device *dev = musb->controller;
        struct platform_device *pdev = to_platform_device(dev->parent);
        struct dsps_glue *glue = platform_get_drvdata(pdev);
        const struct dsps_musb_wrapper *wrp = glue->wrp;
        void __iomem *reg_base = musb->ctrl_base;
        u32 epmask, coremask;

        /* Workaround: setup IRQs through both register sets. */
        epmask = ((musb->epmask & wrp->txep_mask) << wrp->txep_shift) |
               ((musb->epmask & wrp->rxep_mask) << wrp->rxep_shift);
        coremask = (wrp->usb_bitmap & ~MUSB_INTR_SOF);

        musb_writel(reg_base, wrp->epintr_set, epmask);
        musb_writel(reg_base, wrp->coreintr_set, coremask);
        /* start polling for ID change in dual-role idle mode */
        if (musb->xceiv->otg->state == OTG_STATE_B_IDLE &&
                        musb->port_mode == MUSB_OTG)
                dsps_mod_timer(glue, -1);
}

/**
 * dsps_musb_disable - disable HDRC and flush interrupts
 */
static void dsps_musb_disable(struct musb *musb)
{
        struct device *dev = musb->controller;
        struct platform_device *pdev = to_platform_device(dev->parent);
        struct dsps_glue *glue = platform_get_drvdata(pdev);
        const struct dsps_musb_wrapper *wrp = glue->wrp;
        void __iomem *reg_base = musb->ctrl_base;

        musb_writel(reg_base, wrp->coreintr_clear, wrp->usb_bitmap);
        musb_writel(reg_base, wrp->epintr_clear,
                         wrp->txep_bitmap | wrp->rxep_bitmap);
        del_timer_sync(&musb->dev_timer);
}

/* Caller must take musb->lock */
static int dsps_check_status(struct musb *musb, void *unused)
{
        void __iomem *mregs = musb->mregs;
        struct device *dev = musb->controller;
        struct dsps_glue *glue = dev_get_drvdata(dev->parent);
        const struct dsps_musb_wrapper *wrp = glue->wrp;
        u8 devctl;
        int skip_session = 0;

        if (glue->vbus_irq)
                del_timer(&musb->dev_timer);

        /*
         * We poll because DSPS IP's won't expose several OTG-critical
         * status change events (from the transceiver) otherwise.
         */
        devctl = musb_readb(mregs, MUSB_DEVCTL);
        dev_dbg(musb->controller, "Poll devctl %02x (%s)\n", devctl,
                                usb_otg_state_string(musb->xceiv->otg->state));

        switch (musb->xceiv->otg->state) {
        case OTG_STATE_A_WAIT_VRISE:
                dsps_mod_timer_optional(glue);
                break;
        case OTG_STATE_A_WAIT_BCON:
                /* keep VBUS on for host-only mode */
                if (musb->port_mode == MUSB_HOST) {
                        dsps_mod_timer_optional(glue);
                        break;
                }
                musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
                skip_session = 1;
                /* fall */

        case OTG_STATE_A_IDLE:
        case OTG_STATE_B_IDLE:
                if (!glue->vbus_irq) {
                        if (devctl & MUSB_DEVCTL_BDEVICE) {
                                musb->xceiv->otg->state = OTG_STATE_B_IDLE;
                                MUSB_DEV_MODE(musb);
                        } else {
                                musb->xceiv->otg->state = OTG_STATE_A_IDLE;
                                MUSB_HST_MODE(musb);
                        }
                        if (!(devctl & MUSB_DEVCTL_SESSION) && !skip_session)
                                musb_writeb(mregs, MUSB_DEVCTL,
                                            MUSB_DEVCTL_SESSION);
                }
                dsps_mod_timer_optional(glue);
                break;
        case OTG_STATE_A_WAIT_VFALL:
                musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
                musb_writel(musb->ctrl_base, wrp->coreintr_set,
                            MUSB_INTR_VBUSERROR << wrp->usb_shift);
                break;
        default:
                break;
        }

        return 0;
}

static void otg_timer(struct timer_list *t)
{
        struct musb *musb = from_timer(musb, t, dev_timer);
        struct device *dev = musb->controller;
        unsigned long flags;
        int err;

        err = pm_runtime_get(dev);
        if ((err != -EINPROGRESS) && err < 0) {
                dev_err(dev, "Poll could not pm_runtime_get: %i\n", err);
                pm_runtime_put_noidle(dev);

                return;
        }

        spin_lock_irqsave(&musb->lock, flags);
        err = musb_queue_resume_work(musb, dsps_check_status, NULL);
        if (err < 0)
                dev_err(dev, "%s resume work: %i\n", __func__, err);
        spin_unlock_irqrestore(&musb->lock, flags);
        pm_runtime_mark_last_busy(dev);
        pm_runtime_put_autosuspend(dev);
}

static void dsps_musb_clear_ep_rxintr(struct musb *musb, int epnum)
{
        u32 epintr;
        struct dsps_glue *glue = dev_get_drvdata(musb->controller->parent);
        const struct dsps_musb_wrapper *wrp = glue->wrp;

        /* musb->lock might already been held */
        epintr = (1 << epnum) << wrp->rxep_shift;
        musb_writel(musb->ctrl_base, wrp->epintr_status, epintr);
}

static irqreturn_t dsps_interrupt(int irq, void *hci)
{
        struct musb  *musb = hci;
        void __iomem *reg_base = musb->ctrl_base;
        struct device *dev = musb->controller;
        struct dsps_glue *glue = dev_get_drvdata(dev->parent);
        const struct dsps_musb_wrapper *wrp = glue->wrp;
        unsigned long flags;
        irqreturn_t ret = IRQ_NONE;
        u32 epintr, usbintr;

        spin_lock_irqsave(&musb->lock, flags);

        /* Get endpoint interrupts */
        epintr = musb_readl(reg_base, wrp->epintr_status);
        musb->int_rx = (epintr & wrp->rxep_bitmap) >> wrp->rxep_shift;
        musb->int_tx = (epintr & wrp->txep_bitmap) >> wrp->txep_shift;

        if (epintr)
                musb_writel(reg_base, wrp->epintr_status, epintr);

        /* Get usb core interrupts */
        usbintr = musb_readl(reg_base, wrp->coreintr_status);
        if (!usbintr && !epintr)
                goto out;

        musb->int_usb = (usbintr & wrp->usb_bitmap) >> wrp->usb_shift;
        if (usbintr)
                musb_writel(reg_base, wrp->coreintr_status, usbintr);

        dev_dbg(musb->controller, "usbintr (%x) epintr(%x)\n",
                        usbintr, epintr);

        if (usbintr & ((1 << wrp->drvvbus) << wrp->usb_shift)) {
                int drvvbus = musb_readl(reg_base, wrp->status);
                void __iomem *mregs = musb->mregs;
                u8 devctl = musb_readb(mregs, MUSB_DEVCTL);
                int err;

                err = musb->int_usb & MUSB_INTR_VBUSERROR;
                if (err) {
                        /*
                         * The Mentor core doesn't debounce VBUS as needed
                         * to cope with device connect current spikes. This
                         * means it's not uncommon for bus-powered devices
                         * to get VBUS errors during enumeration.
                         *
                         * This is a workaround, but newer RTL from Mentor
                         * seems to allow a better one: "re"-starting sessions
                         * without waiting for VBUS to stop registering in
                         * devctl.
                         */
                        musb->int_usb &= ~MUSB_INTR_VBUSERROR;
                        musb->xceiv->otg->state = OTG_STATE_A_WAIT_VFALL;
                        dsps_mod_timer_optional(glue);
                        WARNING("VBUS error workaround (delay coming)\n");
                } else if (drvvbus) {
                        MUSB_HST_MODE(musb);
                        musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
                        dsps_mod_timer_optional(glue);
                } else {
                        musb->is_active = 0;
                        MUSB_DEV_MODE(musb);
                        musb->xceiv->otg->state = OTG_STATE_B_IDLE;
                }

                /* NOTE: this must complete power-on within 100 ms. */
                dev_dbg(musb->controller, "VBUS %s (%s)%s, devctl %02x\n",
                                drvvbus ? "on" : "off",
                                usb_otg_state_string(musb->xceiv->otg->state),
                                err ? " ERROR" : "",
                                devctl);
                ret = IRQ_HANDLED;
        }

        if (musb->int_tx || musb->int_rx || musb->int_usb)
                ret |= musb_interrupt(musb);

        /* Poll for ID change and connect */
        switch (musb->xceiv->otg->state) {
        case OTG_STATE_B_IDLE:
        case OTG_STATE_A_WAIT_BCON:
                dsps_mod_timer_optional(glue);
                break;
        default:
                break;
        }

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

        return ret;
}

static int dsps_musb_dbg_init(struct musb *musb, struct dsps_glue *glue)
{
        struct dentry *root;
        char buf[128];

        sprintf(buf, "%s.dsps", dev_name(musb->controller));
        root = debugfs_create_dir(buf, NULL);
        glue->dbgfs_root = root;

        glue->regset.regs = dsps_musb_regs;
        glue->regset.nregs = ARRAY_SIZE(dsps_musb_regs);
        glue->regset.base = musb->ctrl_base;

        debugfs_create_regset32("regdump", S_IRUGO, root, &glue->regset);
        return 0;
}

static int dsps_musb_init(struct musb *musb)
{
        struct device *dev = musb->controller;
        struct dsps_glue *glue = dev_get_drvdata(dev->parent);
        struct platform_device *parent = to_platform_device(dev->parent);
        const struct dsps_musb_wrapper *wrp = glue->wrp;
        void __iomem *reg_base;
        struct resource *r;
        u32 rev, val;
        int ret;

        r = platform_get_resource_byname(parent, IORESOURCE_MEM, "control");
        reg_base = devm_ioremap_resource(dev, r);
        if (IS_ERR(reg_base))
                return PTR_ERR(reg_base);
        musb->ctrl_base = reg_base;

        /* NOP driver needs change if supporting dual instance */
        musb->xceiv = devm_usb_get_phy_by_phandle(dev->parent, "phys", 0);
        if (IS_ERR(musb->xceiv))
                return PTR_ERR(musb->xceiv);

        musb->phy = devm_phy_get(dev->parent, "usb2-phy");

        /* Returns zero if e.g. not clocked */
        rev = musb_readl(reg_base, wrp->revision);
        if (!rev)
                return -ENODEV;

        if (IS_ERR(musb->phy))  {
                musb->phy = NULL;
        } else {
                ret = phy_init(musb->phy);
                if (ret < 0)
                        return ret;
                ret = phy_power_on(musb->phy);
                if (ret) {
                        phy_exit(musb->phy);
                        return ret;
                }
        }

        timer_setup(&musb->dev_timer, otg_timer, 0);

        /* Reset the musb */
        musb_writel(reg_base, wrp->control, (1 << wrp->reset));

        musb->isr = dsps_interrupt;

        /* reset the otgdisable bit, needed for host mode to work */
        val = musb_readl(reg_base, wrp->phy_utmi);
        val &= ~(1 << wrp->otg_disable);
        musb_writel(musb->ctrl_base, wrp->phy_utmi, val);

        /*
         *  Check whether the dsps version has babble control enabled.
         * In latest silicon revision the babble control logic is enabled.
         * If MUSB_BABBLE_CTL returns 0x4 then we have the babble control
         * logic enabled.
         */
        val = musb_readb(musb->mregs, MUSB_BABBLE_CTL);
        if (val & MUSB_BABBLE_RCV_DISABLE) {
                glue->sw_babble_enabled = true;
                val |= MUSB_BABBLE_SW_SESSION_CTRL;
                musb_writeb(musb->mregs, MUSB_BABBLE_CTL, val);
        }

        dsps_mod_timer(glue, -1);

        return dsps_musb_dbg_init(musb, glue);
}

static int dsps_musb_exit(struct musb *musb)
{
        struct device *dev = musb->controller;
        struct dsps_glue *glue = dev_get_drvdata(dev->parent);

        del_timer_sync(&musb->dev_timer);
        phy_power_off(musb->phy);
        phy_exit(musb->phy);
        debugfs_remove_recursive(glue->dbgfs_root);

        return 0;
}

static int dsps_musb_set_mode(struct musb *musb, u8 mode)
{
        struct device *dev = musb->controller;
        struct dsps_glue *glue = dev_get_drvdata(dev->parent);
        const struct dsps_musb_wrapper *wrp = glue->wrp;
        void __iomem *ctrl_base = musb->ctrl_base;
        u32 reg;

        reg = musb_readl(ctrl_base, wrp->mode);

        switch (mode) {
        case MUSB_HOST:
                reg &= ~(1 << wrp->iddig);

                /*
                 * if we're setting mode to host-only or device-only, we're
                 * going to ignore whatever the PHY sends us and just force
                 * ID pin status by SW
                 */
                reg |= (1 << wrp->iddig_mux);

                musb_writel(ctrl_base, wrp->mode, reg);
                musb_writel(ctrl_base, wrp->phy_utmi, 0x02);
                break;
        case MUSB_PERIPHERAL:
                reg |= (1 << wrp->iddig);

                /*
                 * if we're setting mode to host-only or device-only, we're
                 * going to ignore whatever the PHY sends us and just force
                 * ID pin status by SW
                 */
                reg |= (1 << wrp->iddig_mux);

                musb_writel(ctrl_base, wrp->mode, reg);
                break;
        case MUSB_OTG:
                musb_writel(ctrl_base, wrp->phy_utmi, 0x02);
                break;
        default:
                dev_err(glue->dev, "unsupported mode %d\n", mode);
                return -EINVAL;
        }

        return 0;
}

static bool dsps_sw_babble_control(struct musb *musb)
{
        u8 babble_ctl;
        bool session_restart =  false;

        babble_ctl = musb_readb(musb->mregs, MUSB_BABBLE_CTL);
        dev_dbg(musb->controller, "babble: MUSB_BABBLE_CTL value %x\n",
                babble_ctl);
        /*
         * check line monitor flag to check whether babble is
         * due to noise
         */
        dev_dbg(musb->controller, "STUCK_J is %s\n",
                babble_ctl & MUSB_BABBLE_STUCK_J ? "set" : "reset");

        if (babble_ctl & MUSB_BABBLE_STUCK_J) {
                int timeout = 10;

                /*
                 * babble is due to noise, then set transmit idle (d7 bit)
                 * to resume normal operation
                 */
                babble_ctl = musb_readb(musb->mregs, MUSB_BABBLE_CTL);
                babble_ctl |= MUSB_BABBLE_FORCE_TXIDLE;
                musb_writeb(musb->mregs, MUSB_BABBLE_CTL, babble_ctl);

                /* wait till line monitor flag cleared */
                dev_dbg(musb->controller, "Set TXIDLE, wait J to clear\n");
                do {
                        babble_ctl = musb_readb(musb->mregs, MUSB_BABBLE_CTL);
                        udelay(1);
                } while ((babble_ctl & MUSB_BABBLE_STUCK_J) && timeout--);

                /* check whether stuck_at_j bit cleared */
                if (babble_ctl & MUSB_BABBLE_STUCK_J) {
                        /*
                         * real babble condition has occurred
                         * restart the controller to start the
                         * session again
                         */
                        dev_dbg(musb->controller, "J not cleared, misc (%x)\n",
                                babble_ctl);
                        session_restart = true;
                }
        } else {
                session_restart = true;
        }

        return session_restart;
}

static int dsps_musb_recover(struct musb *musb)
{
        struct device *dev = musb->controller;
        struct dsps_glue *glue = dev_get_drvdata(dev->parent);
        int session_restart = 0;

        if (glue->sw_babble_enabled)
                session_restart = dsps_sw_babble_control(musb);
        else
                session_restart = 1;

        return session_restart ? 0 : -EPIPE;
}

/* Similar to am35x, dm81xx support only 32-bit read operation */
static void dsps_read_fifo32(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
{
        void __iomem *fifo = hw_ep->fifo;

        if (len >= 4) {
                ioread32_rep(fifo, dst, len >> 2);
                dst += len & ~0x03;
                len &= 0x03;
        }

        /* Read any remaining 1 to 3 bytes */
        if (len > 0) {
                u32 val = musb_readl(fifo, 0);
                memcpy(dst, &val, len);
        }
}

#ifdef CONFIG_USB_TI_CPPI41_DMA
static void dsps_dma_controller_callback(struct dma_controller *c)
{
        struct musb *musb = c->musb;
        struct dsps_glue *glue = dev_get_drvdata(musb->controller->parent);
        void __iomem *usbss_base = glue->usbss_base;
        u32 status;

        status = musb_readl(usbss_base, USBSS_IRQ_STATUS);
        if (status & USBSS_IRQ_PD_COMP)
                musb_writel(usbss_base, USBSS_IRQ_STATUS, USBSS_IRQ_PD_COMP);
}

static struct dma_controller *
dsps_dma_controller_create(struct musb *musb, void __iomem *base)
{
        struct dma_controller *controller;
        struct dsps_glue *glue = dev_get_drvdata(musb->controller->parent);
        void __iomem *usbss_base = glue->usbss_base;

        controller = cppi41_dma_controller_create(musb, base);
        if (IS_ERR_OR_NULL(controller))
                return controller;

        musb_writel(usbss_base, USBSS_IRQ_ENABLER, USBSS_IRQ_PD_COMP);
        controller->dma_callback = dsps_dma_controller_callback;

        return controller;
}

static void dsps_dma_controller_destroy(struct dma_controller *c)
{
        struct musb *musb = c->musb;
        struct dsps_glue *glue = dev_get_drvdata(musb->controller->parent);
        void __iomem *usbss_base = glue->usbss_base;

        musb_writel(usbss_base, USBSS_IRQ_CLEARR, USBSS_IRQ_PD_COMP);
        cppi41_dma_controller_destroy(c);
}

#ifdef CONFIG_PM_SLEEP
static void dsps_dma_controller_suspend(struct dsps_glue *glue)
{
        void __iomem *usbss_base = glue->usbss_base;

        musb_writel(usbss_base, USBSS_IRQ_CLEARR, USBSS_IRQ_PD_COMP);
}

static void dsps_dma_controller_resume(struct dsps_glue *glue)
{
        void __iomem *usbss_base = glue->usbss_base;

        musb_writel(usbss_base, USBSS_IRQ_ENABLER, USBSS_IRQ_PD_COMP);
}
#endif
#else /* CONFIG_USB_TI_CPPI41_DMA */
#ifdef CONFIG_PM_SLEEP
static void dsps_dma_controller_suspend(struct dsps_glue *glue) {}
static void dsps_dma_controller_resume(struct dsps_glue *glue) {}
#endif
#endif /* CONFIG_USB_TI_CPPI41_DMA */

static struct musb_platform_ops dsps_ops = {
        .quirks         = MUSB_DMA_CPPI41 | MUSB_INDEXED_EP,
        .init           = dsps_musb_init,
        .exit           = dsps_musb_exit,

#ifdef CONFIG_USB_TI_CPPI41_DMA
        .dma_init       = dsps_dma_controller_create,
        .dma_exit       = dsps_dma_controller_destroy,
#endif
        .enable         = dsps_musb_enable,
        .disable        = dsps_musb_disable,

        .set_mode       = dsps_musb_set_mode,
        .recover        = dsps_musb_recover,
        .clear_ep_rxintr = dsps_musb_clear_ep_rxintr,
};

static u64 musb_dmamask = DMA_BIT_MASK(32);

static int get_int_prop(struct device_node *dn, const char *s)
{
        int ret;
        u32 val;

        ret = of_property_read_u32(dn, s, &val);
        if (ret)
                return 0;
        return val;
}

static int dsps_create_musb_pdev(struct dsps_glue *glue,
                struct platform_device *parent)
{
        struct musb_hdrc_platform_data pdata;
        struct resource resources[2];
        struct resource *res;
        struct device *dev = &parent->dev;
        struct musb_hdrc_config *config;
        struct platform_device *musb;
        struct device_node *dn = parent->dev.of_node;
        int ret, val;

        memset(resources, 0, sizeof(resources));
        res = platform_get_resource_byname(parent, IORESOURCE_MEM, "mc");
        if (!res) {
                dev_err(dev, "failed to get memory.\n");
                return -EINVAL;
        }
        resources[0] = *res;

        res = platform_get_resource_byname(parent, IORESOURCE_IRQ, "mc");
        if (!res) {
                dev_err(dev, "failed to get irq.\n");
                return -EINVAL;
        }
        resources[1] = *res;

        /* allocate the child platform device */
        musb = platform_device_alloc("musb-hdrc",
                        (resources[0].start & 0xFFF) == 0x400 ? 0 : 1);
        if (!musb) {
                dev_err(dev, "failed to allocate musb device\n");
                return -ENOMEM;
        }

        musb->dev.parent                = dev;
        musb->dev.dma_mask              = &musb_dmamask;
        musb->dev.coherent_dma_mask     = musb_dmamask;
        device_set_of_node_from_dev(&musb->dev, &parent->dev);

        glue->musb = musb;

        ret = platform_device_add_resources(musb, resources,
                        ARRAY_SIZE(resources));
        if (ret) {
                dev_err(dev, "failed to add resources\n");
                goto err;
        }

        config = devm_kzalloc(&parent->dev, sizeof(*config), GFP_KERNEL);
        if (!config) {
                ret = -ENOMEM;
                goto err;
        }
        pdata.config = config;
        pdata.platform_ops = &dsps_ops;

        config->num_eps = get_int_prop(dn, "mentor,num-eps");
        config->ram_bits = get_int_prop(dn, "mentor,ram-bits");
        config->host_port_deassert_reset_at_resume = 1;
        pdata.mode = musb_get_mode(dev);
        /* DT keeps this entry in mA, musb expects it as per USB spec */
        pdata.power = get_int_prop(dn, "mentor,power") / 2;

        ret = of_property_read_u32(dn, "mentor,multipoint", &val);
        if (!ret && val)
                config->multipoint = true;

        config->maximum_speed = usb_get_maximum_speed(&parent->dev);
        switch (config->maximum_speed) {
        case USB_SPEED_LOW:
        case USB_SPEED_FULL:
                break;
        case USB_SPEED_SUPER:
                dev_warn(dev, "ignore incorrect maximum_speed "
                                "(super-speed) setting in dts");
                /* fall through */
        default:
                config->maximum_speed = USB_SPEED_HIGH;
        }

        ret = platform_device_add_data(musb, &pdata, sizeof(pdata));
        if (ret) {
                dev_err(dev, "failed to add platform_data\n");
                goto err;
        }

        ret = platform_device_add(musb);
        if (ret) {
                dev_err(dev, "failed to register musb device\n");
                goto err;
        }
        return 0;

err:
        platform_device_put(musb);
        return ret;
}

static irqreturn_t dsps_vbus_threaded_irq(int irq, void *priv)
{
        struct dsps_glue *glue = priv;
        struct musb *musb = platform_get_drvdata(glue->musb);

        if (!musb)
                return IRQ_NONE;

        dev_dbg(glue->dev, "VBUS interrupt\n");
        dsps_mod_timer(glue, 0);

        return IRQ_HANDLED;
}

static int dsps_setup_optional_vbus_irq(struct platform_device *pdev,
                                        struct dsps_glue *glue)
{
        int error;

        glue->vbus_irq = platform_get_irq_byname(pdev, "vbus");
        if (glue->vbus_irq == -EPROBE_DEFER)
                return -EPROBE_DEFER;

        if (glue->vbus_irq <= 0) {
                glue->vbus_irq = 0;
                return 0;
        }

        error = devm_request_threaded_irq(glue->dev, glue->vbus_irq,
                                          NULL, dsps_vbus_threaded_irq,
                                          IRQF_ONESHOT,
                                          "vbus", glue);
        if (error) {
                glue->vbus_irq = 0;
                return error;
        }
        dev_dbg(glue->dev, "VBUS irq %i configured\n", glue->vbus_irq);

        return 0;
}

static int dsps_probe(struct platform_device *pdev)
{
        const struct of_device_id *match;
        const struct dsps_musb_wrapper *wrp;
        struct dsps_glue *glue;
        int ret;

        if (!strcmp(pdev->name, "musb-hdrc"))
                return -ENODEV;

        match = of_match_node(musb_dsps_of_match, pdev->dev.of_node);
        if (!match) {
                dev_err(&pdev->dev, "fail to get matching of_match struct\n");
                return -EINVAL;
        }
        wrp = match->data;

        if (of_device_is_compatible(pdev->dev.of_node, "ti,musb-dm816"))
                dsps_ops.read_fifo = dsps_read_fifo32;

        /* allocate glue */
        glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
        if (!glue)
                return -ENOMEM;

        glue->dev = &pdev->dev;
        glue->wrp = wrp;
        glue->usbss_base = of_iomap(pdev->dev.parent->of_node, 0);
        if (!glue->usbss_base)
                return -ENXIO;

        if (usb_get_dr_mode(&pdev->dev) == USB_DR_MODE_PERIPHERAL) {
                ret = dsps_setup_optional_vbus_irq(pdev, glue);
                if (ret)
                        goto err_iounmap;
        }

        platform_set_drvdata(pdev, glue);
        pm_runtime_enable(&pdev->dev);
        ret = dsps_create_musb_pdev(glue, pdev);
        if (ret)
                goto err;

        return 0;

err:
        pm_runtime_disable(&pdev->dev);
err_iounmap:
        iounmap(glue->usbss_base);
        return ret;
}

static int dsps_remove(struct platform_device *pdev)
{
        struct dsps_glue *glue = platform_get_drvdata(pdev);

        platform_device_unregister(glue->musb);

        pm_runtime_disable(&pdev->dev);
        iounmap(glue->usbss_base);

        return 0;
}

static const struct dsps_musb_wrapper am33xx_driver_data = {
        .revision               = 0x00,
        .control                = 0x14,
        .status                 = 0x18,
        .epintr_set             = 0x38,
        .epintr_clear           = 0x40,
        .epintr_status          = 0x30,
        .coreintr_set           = 0x3c,
        .coreintr_clear         = 0x44,
        .coreintr_status        = 0x34,
        .phy_utmi               = 0xe0,
        .mode                   = 0xe8,
        .tx_mode                = 0x70,
        .rx_mode                = 0x74,
        .reset                  = 0,
        .otg_disable            = 21,
        .iddig                  = 8,
        .iddig_mux              = 7,
        .usb_shift              = 0,
        .usb_mask               = 0x1ff,
        .usb_bitmap             = (0x1ff << 0),
        .drvvbus                = 8,
        .txep_shift             = 0,
        .txep_mask              = 0xffff,
        .txep_bitmap            = (0xffff << 0),
        .rxep_shift             = 16,
        .rxep_mask              = 0xfffe,
        .rxep_bitmap            = (0xfffe << 16),
        .poll_timeout           = 2000, /* ms */
};

static const struct of_device_id musb_dsps_of_match[] = {
        { .compatible = "ti,musb-am33xx",
                .data = &am33xx_driver_data, },
        { .compatible = "ti,musb-dm816",
                .data = &am33xx_driver_data, },
        {  },
};
MODULE_DEVICE_TABLE(of, musb_dsps_of_match);

#ifdef CONFIG_PM_SLEEP
static int dsps_suspend(struct device *dev)
{
        struct dsps_glue *glue = dev_get_drvdata(dev);
        const struct dsps_musb_wrapper *wrp = glue->wrp;
        struct musb *musb = platform_get_drvdata(glue->musb);
        void __iomem *mbase;
        int ret;

        if (!musb)
                /* This can happen if the musb device is in -EPROBE_DEFER */
                return 0;

        ret = pm_runtime_get_sync(dev);
        if (ret < 0) {
                pm_runtime_put_noidle(dev);
                return ret;
        }

        del_timer_sync(&musb->dev_timer);

        mbase = musb->ctrl_base;
        glue->context.control = musb_readl(mbase, wrp->control);
        glue->context.epintr = musb_readl(mbase, wrp->epintr_set);
        glue->context.coreintr = musb_readl(mbase, wrp->coreintr_set);
        glue->context.phy_utmi = musb_readl(mbase, wrp->phy_utmi);
        glue->context.mode = musb_readl(mbase, wrp->mode);
        glue->context.tx_mode = musb_readl(mbase, wrp->tx_mode);
        glue->context.rx_mode = musb_readl(mbase, wrp->rx_mode);

        dsps_dma_controller_suspend(glue);

        return 0;
}

static int dsps_resume(struct device *dev)
{
        struct dsps_glue *glue = dev_get_drvdata(dev);
        const struct dsps_musb_wrapper *wrp = glue->wrp;
        struct musb *musb = platform_get_drvdata(glue->musb);
        void __iomem *mbase;

        if (!musb)
                return 0;

        dsps_dma_controller_resume(glue);

        mbase = musb->ctrl_base;
        musb_writel(mbase, wrp->control, glue->context.control);
        musb_writel(mbase, wrp->epintr_set, glue->context.epintr);
        musb_writel(mbase, wrp->coreintr_set, glue->context.coreintr);
        musb_writel(mbase, wrp->phy_utmi, glue->context.phy_utmi);
        musb_writel(mbase, wrp->mode, glue->context.mode);
        musb_writel(mbase, wrp->tx_mode, glue->context.tx_mode);
        musb_writel(mbase, wrp->rx_mode, glue->context.rx_mode);
        if (musb->xceiv->otg->state == OTG_STATE_B_IDLE &&
            musb->port_mode == MUSB_OTG)
                dsps_mod_timer(glue, -1);

        pm_runtime_put(dev);

        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(dsps_pm_ops, dsps_suspend, dsps_resume);

static struct platform_driver dsps_usbss_driver = {
        .probe          = dsps_probe,
        .remove         = dsps_remove,
        .driver         = {
                .name   = "musb-dsps",
                .pm     = &dsps_pm_ops,
                .of_match_table = musb_dsps_of_match,
        },
};

MODULE_DESCRIPTION("TI DSPS MUSB Glue Layer");
MODULE_AUTHOR("Ravi B <ravibabu@ti.com>");
MODULE_AUTHOR("Ajay Kumar Gupta <ajay.gupta@ti.com>");
MODULE_LICENSE("GPL v2");

module_platform_driver(dsps_usbss_driver);