usb: dwc3: setup phys earlier

[mirror_ubuntu-artful-kernel.git] / drivers / usb / dwc3 / core.c

/**
 * core.c - DesignWare USB3 DRD Controller Core file
 *
 * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
 *
 * Authors: Felipe Balbi <balbi@ti.com>,
 *          Sebastian Andrzej Siewior <bigeasy@linutronix.de>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2  of
 * the License as published by the Free Software Foundation.
 *
 * 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/>.
 */

#include <linux/version.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/list.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/of.h>
#include <linux/acpi.h>

#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/of.h>
#include <linux/usb/otg.h>

#include "platform_data.h"
#include "core.h"
#include "gadget.h"
#include "io.h"

#include "debug.h"

/* -------------------------------------------------------------------------- */

void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
{
        u32 reg;

        reg = dwc3_readl(dwc->regs, DWC3_GCTL);
        reg &= ~(DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG));
        reg |= DWC3_GCTL_PRTCAPDIR(mode);
        dwc3_writel(dwc->regs, DWC3_GCTL, reg);
}

/**
 * dwc3_core_soft_reset - Issues core soft reset and PHY reset
 * @dwc: pointer to our context structure
 */
static int dwc3_core_soft_reset(struct dwc3 *dwc)
{
        u32             reg;
        int             ret;

        /* Before Resetting PHY, put Core in Reset */
        reg = dwc3_readl(dwc->regs, DWC3_GCTL);
        reg |= DWC3_GCTL_CORESOFTRESET;
        dwc3_writel(dwc->regs, DWC3_GCTL, reg);

        /* Assert USB3 PHY reset */
        reg = dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0));
        reg |= DWC3_GUSB3PIPECTL_PHYSOFTRST;
        dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(0), reg);

        /* Assert USB2 PHY reset */
        reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
        reg |= DWC3_GUSB2PHYCFG_PHYSOFTRST;
        dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);

        usb_phy_init(dwc->usb2_phy);
        usb_phy_init(dwc->usb3_phy);
        ret = phy_init(dwc->usb2_generic_phy);
        if (ret < 0)
                return ret;

        ret = phy_init(dwc->usb3_generic_phy);
        if (ret < 0) {
                phy_exit(dwc->usb2_generic_phy);
                return ret;
        }
        mdelay(100);

        /* Clear USB3 PHY reset */
        reg = dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0));
        reg &= ~DWC3_GUSB3PIPECTL_PHYSOFTRST;
        dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(0), reg);

        /* Clear USB2 PHY reset */
        reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
        reg &= ~DWC3_GUSB2PHYCFG_PHYSOFTRST;
        dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);

        mdelay(100);

        /* After PHYs are stable we can take Core out of reset state */
        reg = dwc3_readl(dwc->regs, DWC3_GCTL);
        reg &= ~DWC3_GCTL_CORESOFTRESET;
        dwc3_writel(dwc->regs, DWC3_GCTL, reg);

        return 0;
}

/**
 * dwc3_soft_reset - Issue soft reset
 * @dwc: Pointer to our controller context structure
 */
static int dwc3_soft_reset(struct dwc3 *dwc)
{
        unsigned long timeout;
        u32 reg;

        timeout = jiffies + msecs_to_jiffies(500);
        dwc3_writel(dwc->regs, DWC3_DCTL, DWC3_DCTL_CSFTRST);
        do {
                reg = dwc3_readl(dwc->regs, DWC3_DCTL);
                if (!(reg & DWC3_DCTL_CSFTRST))
                        break;

                if (time_after(jiffies, timeout)) {
                        dev_err(dwc->dev, "Reset Timed Out\n");
                        return -ETIMEDOUT;
                }

                cpu_relax();
        } while (true);

        return 0;
}

/**
 * dwc3_free_one_event_buffer - Frees one event buffer
 * @dwc: Pointer to our controller context structure
 * @evt: Pointer to event buffer to be freed
 */
static void dwc3_free_one_event_buffer(struct dwc3 *dwc,
                struct dwc3_event_buffer *evt)
{
        dma_free_coherent(dwc->dev, evt->length, evt->buf, evt->dma);
}

/**
 * dwc3_alloc_one_event_buffer - Allocates one event buffer structure
 * @dwc: Pointer to our controller context structure
 * @length: size of the event buffer
 *
 * Returns a pointer to the allocated event buffer structure on success
 * otherwise ERR_PTR(errno).
 */
static struct dwc3_event_buffer *dwc3_alloc_one_event_buffer(struct dwc3 *dwc,
                unsigned length)
{
        struct dwc3_event_buffer        *evt;

        evt = devm_kzalloc(dwc->dev, sizeof(*evt), GFP_KERNEL);
        if (!evt)
                return ERR_PTR(-ENOMEM);

        evt->dwc        = dwc;
        evt->length     = length;
        evt->buf        = dma_alloc_coherent(dwc->dev, length,
                        &evt->dma, GFP_KERNEL);
        if (!evt->buf)
                return ERR_PTR(-ENOMEM);

        return evt;
}

/**
 * dwc3_free_event_buffers - frees all allocated event buffers
 * @dwc: Pointer to our controller context structure
 */
static void dwc3_free_event_buffers(struct dwc3 *dwc)
{
        struct dwc3_event_buffer        *evt;
        int i;

        for (i = 0; i < dwc->num_event_buffers; i++) {
                evt = dwc->ev_buffs[i];
                if (evt)
                        dwc3_free_one_event_buffer(dwc, evt);
        }
}

/**
 * dwc3_alloc_event_buffers - Allocates @num event buffers of size @length
 * @dwc: pointer to our controller context structure
 * @length: size of event buffer
 *
 * Returns 0 on success otherwise negative errno. In the error case, dwc
 * may contain some buffers allocated but not all which were requested.
 */
static int dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned length)
{
        int                     num;
        int                     i;

        num = DWC3_NUM_INT(dwc->hwparams.hwparams1);
        dwc->num_event_buffers = num;

        dwc->ev_buffs = devm_kzalloc(dwc->dev, sizeof(*dwc->ev_buffs) * num,
                        GFP_KERNEL);
        if (!dwc->ev_buffs)
                return -ENOMEM;

        for (i = 0; i < num; i++) {
                struct dwc3_event_buffer        *evt;

                evt = dwc3_alloc_one_event_buffer(dwc, length);
                if (IS_ERR(evt)) {
                        dev_err(dwc->dev, "can't allocate event buffer\n");
                        return PTR_ERR(evt);
                }
                dwc->ev_buffs[i] = evt;
        }

        return 0;
}

/**
 * dwc3_event_buffers_setup - setup our allocated event buffers
 * @dwc: pointer to our controller context structure
 *
 * Returns 0 on success otherwise negative errno.
 */
static int dwc3_event_buffers_setup(struct dwc3 *dwc)
{
        struct dwc3_event_buffer        *evt;
        int                             n;

        for (n = 0; n < dwc->num_event_buffers; n++) {
                evt = dwc->ev_buffs[n];
                dev_dbg(dwc->dev, "Event buf %p dma %08llx length %d\n",
                                evt->buf, (unsigned long long) evt->dma,
                                evt->length);

                evt->lpos = 0;

                dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(n),
                                lower_32_bits(evt->dma));
                dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(n),
                                upper_32_bits(evt->dma));
                dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(n),
                                DWC3_GEVNTSIZ_SIZE(evt->length));
                dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(n), 0);
        }

        return 0;
}

static void dwc3_event_buffers_cleanup(struct dwc3 *dwc)
{
        struct dwc3_event_buffer        *evt;
        int                             n;

        for (n = 0; n < dwc->num_event_buffers; n++) {
                evt = dwc->ev_buffs[n];

                evt->lpos = 0;

                dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(n), 0);
                dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(n), 0);
                dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(n), DWC3_GEVNTSIZ_INTMASK
                                | DWC3_GEVNTSIZ_SIZE(0));
                dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(n), 0);
        }
}

static int dwc3_alloc_scratch_buffers(struct dwc3 *dwc)
{
        if (!dwc->has_hibernation)
                return 0;

        if (!dwc->nr_scratch)
                return 0;

        dwc->scratchbuf = kmalloc_array(dwc->nr_scratch,
                        DWC3_SCRATCHBUF_SIZE, GFP_KERNEL);
        if (!dwc->scratchbuf)
                return -ENOMEM;

        return 0;
}

static int dwc3_setup_scratch_buffers(struct dwc3 *dwc)
{
        dma_addr_t scratch_addr;
        u32 param;
        int ret;

        if (!dwc->has_hibernation)
                return 0;

        if (!dwc->nr_scratch)
                return 0;

         /* should never fall here */
        if (!WARN_ON(dwc->scratchbuf))
                return 0;

        scratch_addr = dma_map_single(dwc->dev, dwc->scratchbuf,
                        dwc->nr_scratch * DWC3_SCRATCHBUF_SIZE,
                        DMA_BIDIRECTIONAL);
        if (dma_mapping_error(dwc->dev, scratch_addr)) {
                dev_err(dwc->dev, "failed to map scratch buffer\n");
                ret = -EFAULT;
                goto err0;
        }

        dwc->scratch_addr = scratch_addr;

        param = lower_32_bits(scratch_addr);

        ret = dwc3_send_gadget_generic_command(dwc,
                        DWC3_DGCMD_SET_SCRATCHPAD_ADDR_LO, param);
        if (ret < 0)
                goto err1;

        param = upper_32_bits(scratch_addr);

        ret = dwc3_send_gadget_generic_command(dwc,
                        DWC3_DGCMD_SET_SCRATCHPAD_ADDR_HI, param);
        if (ret < 0)
                goto err1;

        return 0;

err1:
        dma_unmap_single(dwc->dev, dwc->scratch_addr, dwc->nr_scratch *
                        DWC3_SCRATCHBUF_SIZE, DMA_BIDIRECTIONAL);

err0:
        return ret;
}

static void dwc3_free_scratch_buffers(struct dwc3 *dwc)
{
        if (!dwc->has_hibernation)
                return;

        if (!dwc->nr_scratch)
                return;

         /* should never fall here */
        if (!WARN_ON(dwc->scratchbuf))
                return;

        dma_unmap_single(dwc->dev, dwc->scratch_addr, dwc->nr_scratch *
                        DWC3_SCRATCHBUF_SIZE, DMA_BIDIRECTIONAL);
        kfree(dwc->scratchbuf);
}

static void dwc3_core_num_eps(struct dwc3 *dwc)
{
        struct dwc3_hwparams    *parms = &dwc->hwparams;

        dwc->num_in_eps = DWC3_NUM_IN_EPS(parms);
        dwc->num_out_eps = DWC3_NUM_EPS(parms) - dwc->num_in_eps;

        dwc3_trace(trace_dwc3_core, "found %d IN and %d OUT endpoints",
                        dwc->num_in_eps, dwc->num_out_eps);
}

static void dwc3_cache_hwparams(struct dwc3 *dwc)
{
        struct dwc3_hwparams    *parms = &dwc->hwparams;

        parms->hwparams0 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS0);
        parms->hwparams1 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS1);
        parms->hwparams2 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS2);
        parms->hwparams3 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS3);
        parms->hwparams4 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS4);
        parms->hwparams5 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS5);
        parms->hwparams6 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS6);
        parms->hwparams7 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS7);
        parms->hwparams8 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS8);
}

/**
 * dwc3_phy_setup - Configure USB PHY Interface of DWC3 Core
 * @dwc: Pointer to our controller context structure
 */
static void dwc3_phy_setup(struct dwc3 *dwc)
{
        u32 reg;

        reg = dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0));

        /*
         * Above 1.94a, it is recommended to set DWC3_GUSB3PIPECTL_SUSPHY
         * to '0' during coreConsultant configuration. So default value
         * will be '0' when the core is reset. Application needs to set it
         * to '1' after the core initialization is completed.
         */
        if (dwc->revision > DWC3_REVISION_194A)
                reg |= DWC3_GUSB3PIPECTL_SUSPHY;

        if (dwc->u2ss_inp3_quirk)
                reg |= DWC3_GUSB3PIPECTL_U2SSINP3OK;

        if (dwc->req_p1p2p3_quirk)
                reg |= DWC3_GUSB3PIPECTL_REQP1P2P3;

        if (dwc->del_p1p2p3_quirk)
                reg |= DWC3_GUSB3PIPECTL_DEP1P2P3_EN;

        if (dwc->del_phy_power_chg_quirk)
                reg |= DWC3_GUSB3PIPECTL_DEPOCHANGE;

        if (dwc->lfps_filter_quirk)
                reg |= DWC3_GUSB3PIPECTL_LFPSFILT;

        if (dwc->rx_detect_poll_quirk)
                reg |= DWC3_GUSB3PIPECTL_RX_DETOPOLL;

        if (dwc->tx_de_emphasis_quirk)
                reg |= DWC3_GUSB3PIPECTL_TX_DEEPH(dwc->tx_de_emphasis);

        if (dwc->dis_u3_susphy_quirk)
                reg &= ~DWC3_GUSB3PIPECTL_SUSPHY;

        dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(0), reg);

        reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));

        /*
         * Above 1.94a, it is recommended to set DWC3_GUSB2PHYCFG_SUSPHY to
         * '0' during coreConsultant configuration. So default value will
         * be '0' when the core is reset. Application needs to set it to
         * '1' after the core initialization is completed.
         */
        if (dwc->revision > DWC3_REVISION_194A)
                reg |= DWC3_GUSB2PHYCFG_SUSPHY;

        if (dwc->dis_u2_susphy_quirk)
                reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;

        dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
}

/**
 * dwc3_core_init - Low-level initialization of DWC3 Core
 * @dwc: Pointer to our controller context structure
 *
 * Returns 0 on success otherwise negative errno.
 */
static int dwc3_core_init(struct dwc3 *dwc)
{
        u32                     hwparams4 = dwc->hwparams.hwparams4;
        u32                     reg;
        int                     ret;

        reg = dwc3_readl(dwc->regs, DWC3_GSNPSID);
        /* This should read as U3 followed by revision number */
        if ((reg & DWC3_GSNPSID_MASK) != 0x55330000) {
                dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n");
                ret = -ENODEV;
                goto err0;
        }
        dwc->revision = reg;

        /*
         * Write Linux Version Code to our GUID register so it's easy to figure
         * out which kernel version a bug was found.
         */
        dwc3_writel(dwc->regs, DWC3_GUID, LINUX_VERSION_CODE);

        /* Handle USB2.0-only core configuration */
        if (DWC3_GHWPARAMS3_SSPHY_IFC(dwc->hwparams.hwparams3) ==
                        DWC3_GHWPARAMS3_SSPHY_IFC_DIS) {
                if (dwc->maximum_speed == USB_SPEED_SUPER)
                        dwc->maximum_speed = USB_SPEED_HIGH;
        }

        /* issue device SoftReset too */
        ret = dwc3_soft_reset(dwc);
        if (ret)
                goto err0;

        ret = dwc3_core_soft_reset(dwc);
        if (ret)
                goto err0;

        reg = dwc3_readl(dwc->regs, DWC3_GCTL);
        reg &= ~DWC3_GCTL_SCALEDOWN_MASK;

        switch (DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams1)) {
        case DWC3_GHWPARAMS1_EN_PWROPT_CLK:
                /**
                 * WORKAROUND: DWC3 revisions between 2.10a and 2.50a have an
                 * issue which would cause xHCI compliance tests to fail.
                 *
                 * Because of that we cannot enable clock gating on such
                 * configurations.
                 *
                 * Refers to:
                 *
                 * STAR#9000588375: Clock Gating, SOF Issues when ref_clk-Based
                 * SOF/ITP Mode Used
                 */
                if ((dwc->dr_mode == USB_DR_MODE_HOST ||
                                dwc->dr_mode == USB_DR_MODE_OTG) &&
                                (dwc->revision >= DWC3_REVISION_210A &&
                                dwc->revision <= DWC3_REVISION_250A))
                        reg |= DWC3_GCTL_DSBLCLKGTNG | DWC3_GCTL_SOFITPSYNC;
                else
                        reg &= ~DWC3_GCTL_DSBLCLKGTNG;
                break;
        case DWC3_GHWPARAMS1_EN_PWROPT_HIB:
                /* enable hibernation here */
                dwc->nr_scratch = DWC3_GHWPARAMS4_HIBER_SCRATCHBUFS(hwparams4);

                /*
                 * REVISIT Enabling this bit so that host-mode hibernation
                 * will work. Device-mode hibernation is not yet implemented.
                 */
                reg |= DWC3_GCTL_GBLHIBERNATIONEN;
                break;
        default:
                dev_dbg(dwc->dev, "No power optimization available\n");
        }

        /* check if current dwc3 is on simulation board */
        if (dwc->hwparams.hwparams6 & DWC3_GHWPARAMS6_EN_FPGA) {
                dev_dbg(dwc->dev, "it is on FPGA board\n");
                dwc->is_fpga = true;
        }

        WARN_ONCE(dwc->disable_scramble_quirk && !dwc->is_fpga,
                        "disable_scramble cannot be used on non-FPGA builds\n");

        if (dwc->disable_scramble_quirk && dwc->is_fpga)
                reg |= DWC3_GCTL_DISSCRAMBLE;
        else
                reg &= ~DWC3_GCTL_DISSCRAMBLE;

        if (dwc->u2exit_lfps_quirk)
                reg |= DWC3_GCTL_U2EXIT_LFPS;

        /*
         * WORKAROUND: DWC3 revisions <1.90a have a bug
         * where the device can fail to connect at SuperSpeed
         * and falls back to high-speed mode which causes
         * the device to enter a Connect/Disconnect loop
         */
        if (dwc->revision < DWC3_REVISION_190A)
                reg |= DWC3_GCTL_U2RSTECN;

        dwc3_core_num_eps(dwc);

        dwc3_writel(dwc->regs, DWC3_GCTL, reg);

        ret = dwc3_alloc_scratch_buffers(dwc);
        if (ret)
                goto err1;

        ret = dwc3_setup_scratch_buffers(dwc);
        if (ret)
                goto err2;

        return 0;

err2:
        dwc3_free_scratch_buffers(dwc);

err1:
        usb_phy_shutdown(dwc->usb2_phy);
        usb_phy_shutdown(dwc->usb3_phy);
        phy_exit(dwc->usb2_generic_phy);
        phy_exit(dwc->usb3_generic_phy);

err0:
        return ret;
}

static void dwc3_core_exit(struct dwc3 *dwc)
{
        dwc3_free_scratch_buffers(dwc);
        usb_phy_shutdown(dwc->usb2_phy);
        usb_phy_shutdown(dwc->usb3_phy);
        phy_exit(dwc->usb2_generic_phy);
        phy_exit(dwc->usb3_generic_phy);
}

static int dwc3_core_get_phy(struct dwc3 *dwc)
{
        struct device           *dev = dwc->dev;
        struct device_node      *node = dev->of_node;
        int ret;

        if (node) {
                dwc->usb2_phy = devm_usb_get_phy_by_phandle(dev, "usb-phy", 0);
                dwc->usb3_phy = devm_usb_get_phy_by_phandle(dev, "usb-phy", 1);
        } else {
                dwc->usb2_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
                dwc->usb3_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB3);
        }

        if (IS_ERR(dwc->usb2_phy)) {
                ret = PTR_ERR(dwc->usb2_phy);
                if (ret == -ENXIO || ret == -ENODEV) {
                        dwc->usb2_phy = NULL;
                } else if (ret == -EPROBE_DEFER) {
                        return ret;
                } else {
                        dev_err(dev, "no usb2 phy configured\n");
                        return ret;
                }
        }

        if (IS_ERR(dwc->usb3_phy)) {
                ret = PTR_ERR(dwc->usb3_phy);
                if (ret == -ENXIO || ret == -ENODEV) {
                        dwc->usb3_phy = NULL;
                } else if (ret == -EPROBE_DEFER) {
                        return ret;
                } else {
                        dev_err(dev, "no usb3 phy configured\n");
                        return ret;
                }
        }

        dwc->usb2_generic_phy = devm_phy_get(dev, "usb2-phy");
        if (IS_ERR(dwc->usb2_generic_phy)) {
                ret = PTR_ERR(dwc->usb2_generic_phy);
                if (ret == -ENOSYS || ret == -ENODEV) {
                        dwc->usb2_generic_phy = NULL;
                } else if (ret == -EPROBE_DEFER) {
                        return ret;
                } else {
                        dev_err(dev, "no usb2 phy configured\n");
                        return ret;
                }
        }

        dwc->usb3_generic_phy = devm_phy_get(dev, "usb3-phy");
        if (IS_ERR(dwc->usb3_generic_phy)) {
                ret = PTR_ERR(dwc->usb3_generic_phy);
                if (ret == -ENOSYS || ret == -ENODEV) {
                        dwc->usb3_generic_phy = NULL;
                } else if (ret == -EPROBE_DEFER) {
                        return ret;
                } else {
                        dev_err(dev, "no usb3 phy configured\n");
                        return ret;
                }
        }

        return 0;
}

static int dwc3_core_init_mode(struct dwc3 *dwc)
{
        struct device *dev = dwc->dev;
        int ret;

        switch (dwc->dr_mode) {
        case USB_DR_MODE_PERIPHERAL:
                dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
                ret = dwc3_gadget_init(dwc);
                if (ret) {
                        dev_err(dev, "failed to initialize gadget\n");
                        return ret;
                }
                break;
        case USB_DR_MODE_HOST:
                dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_HOST);
                ret = dwc3_host_init(dwc);
                if (ret) {
                        dev_err(dev, "failed to initialize host\n");
                        return ret;
                }
                break;
        case USB_DR_MODE_OTG:
                dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
                ret = dwc3_host_init(dwc);
                if (ret) {
                        dev_err(dev, "failed to initialize host\n");
                        return ret;
                }

                ret = dwc3_gadget_init(dwc);
                if (ret) {
                        dev_err(dev, "failed to initialize gadget\n");
                        return ret;
                }
                break;
        default:
                dev_err(dev, "Unsupported mode of operation %d\n", dwc->dr_mode);
                return -EINVAL;
        }

        return 0;
}

static void dwc3_core_exit_mode(struct dwc3 *dwc)
{
        switch (dwc->dr_mode) {
        case USB_DR_MODE_PERIPHERAL:
                dwc3_gadget_exit(dwc);
                break;
        case USB_DR_MODE_HOST:
                dwc3_host_exit(dwc);
                break;
        case USB_DR_MODE_OTG:
                dwc3_host_exit(dwc);
                dwc3_gadget_exit(dwc);
                break;
        default:
                /* do nothing */
                break;
        }
}

#define DWC3_ALIGN_MASK         (16 - 1)

static int dwc3_probe(struct platform_device *pdev)
{
        struct device           *dev = &pdev->dev;
        struct dwc3_platform_data *pdata = dev_get_platdata(dev);
        struct device_node      *node = dev->of_node;
        struct resource         *res;
        struct dwc3             *dwc;
        u8                      lpm_nyet_threshold;
        u8                      tx_de_emphasis;
        u8                      hird_threshold;

        int                     ret;

        void __iomem            *regs;
        void                    *mem;

        mem = devm_kzalloc(dev, sizeof(*dwc) + DWC3_ALIGN_MASK, GFP_KERNEL);
        if (!mem)
                return -ENOMEM;

        dwc = PTR_ALIGN(mem, DWC3_ALIGN_MASK + 1);
        dwc->mem = mem;
        dwc->dev = dev;

        res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        if (!res) {
                dev_err(dev, "missing IRQ\n");
                return -ENODEV;
        }
        dwc->xhci_resources[1].start = res->start;
        dwc->xhci_resources[1].end = res->end;
        dwc->xhci_resources[1].flags = res->flags;
        dwc->xhci_resources[1].name = res->name;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res) {
                dev_err(dev, "missing memory resource\n");
                return -ENODEV;
        }

        dwc->xhci_resources[0].start = res->start;
        dwc->xhci_resources[0].end = dwc->xhci_resources[0].start +
                                        DWC3_XHCI_REGS_END;
        dwc->xhci_resources[0].flags = res->flags;
        dwc->xhci_resources[0].name = res->name;

        res->start += DWC3_GLOBALS_REGS_START;

        /*
         * Request memory region but exclude xHCI regs,
         * since it will be requested by the xhci-plat driver.
         */
        regs = devm_ioremap_resource(dev, res);
        if (IS_ERR(regs)) {
                ret = PTR_ERR(regs);
                goto err0;
        }

        dwc->regs       = regs;
        dwc->regs_size  = resource_size(res);

        /* default to highest possible threshold */
        lpm_nyet_threshold = 0xff;

        /* default to -3.5dB de-emphasis */
        tx_de_emphasis = 1;

        /*
         * default to assert utmi_sleep_n and use maximum allowed HIRD
         * threshold value of 0b1100
         */
        hird_threshold = 12;

        if (node) {
                dwc->maximum_speed = of_usb_get_maximum_speed(node);
                dwc->has_lpm_erratum = of_property_read_bool(node,
                                "snps,has-lpm-erratum");
                of_property_read_u8(node, "snps,lpm-nyet-threshold",
                                &lpm_nyet_threshold);
                dwc->is_utmi_l1_suspend = of_property_read_bool(node,
                                "snps,is-utmi-l1-suspend");
                of_property_read_u8(node, "snps,hird-threshold",
                                &hird_threshold);
                dwc->usb3_lpm_capable = of_property_read_bool(node,
                                "snps,usb3_lpm_capable");

                dwc->needs_fifo_resize = of_property_read_bool(node,
                                "tx-fifo-resize");
                dwc->dr_mode = of_usb_get_dr_mode(node);

                dwc->disable_scramble_quirk = of_property_read_bool(node,
                                "snps,disable_scramble_quirk");
                dwc->u2exit_lfps_quirk = of_property_read_bool(node,
                                "snps,u2exit_lfps_quirk");
                dwc->u2ss_inp3_quirk = of_property_read_bool(node,
                                "snps,u2ss_inp3_quirk");
                dwc->req_p1p2p3_quirk = of_property_read_bool(node,
                                "snps,req_p1p2p3_quirk");
                dwc->del_p1p2p3_quirk = of_property_read_bool(node,
                                "snps,del_p1p2p3_quirk");
                dwc->del_phy_power_chg_quirk = of_property_read_bool(node,
                                "snps,del_phy_power_chg_quirk");
                dwc->lfps_filter_quirk = of_property_read_bool(node,
                                "snps,lfps_filter_quirk");
                dwc->rx_detect_poll_quirk = of_property_read_bool(node,
                                "snps,rx_detect_poll_quirk");
                dwc->dis_u3_susphy_quirk = of_property_read_bool(node,
                                "snps,dis_u3_susphy_quirk");
                dwc->dis_u2_susphy_quirk = of_property_read_bool(node,
                                "snps,dis_u2_susphy_quirk");

                dwc->tx_de_emphasis_quirk = of_property_read_bool(node,
                                "snps,tx_de_emphasis_quirk");
                of_property_read_u8(node, "snps,tx_de_emphasis",
                                &tx_de_emphasis);
        } else if (pdata) {
                dwc->maximum_speed = pdata->maximum_speed;
                dwc->has_lpm_erratum = pdata->has_lpm_erratum;
                if (pdata->lpm_nyet_threshold)
                        lpm_nyet_threshold = pdata->lpm_nyet_threshold;
                dwc->is_utmi_l1_suspend = pdata->is_utmi_l1_suspend;
                if (pdata->hird_threshold)
                        hird_threshold = pdata->hird_threshold;

                dwc->needs_fifo_resize = pdata->tx_fifo_resize;
                dwc->usb3_lpm_capable = pdata->usb3_lpm_capable;
                dwc->dr_mode = pdata->dr_mode;

                dwc->disable_scramble_quirk = pdata->disable_scramble_quirk;
                dwc->u2exit_lfps_quirk = pdata->u2exit_lfps_quirk;
                dwc->u2ss_inp3_quirk = pdata->u2ss_inp3_quirk;
                dwc->req_p1p2p3_quirk = pdata->req_p1p2p3_quirk;
                dwc->del_p1p2p3_quirk = pdata->del_p1p2p3_quirk;
                dwc->del_phy_power_chg_quirk = pdata->del_phy_power_chg_quirk;
                dwc->lfps_filter_quirk = pdata->lfps_filter_quirk;
                dwc->rx_detect_poll_quirk = pdata->rx_detect_poll_quirk;
                dwc->dis_u3_susphy_quirk = pdata->dis_u3_susphy_quirk;
                dwc->dis_u2_susphy_quirk = pdata->dis_u2_susphy_quirk;

                dwc->tx_de_emphasis_quirk = pdata->tx_de_emphasis_quirk;
                if (pdata->tx_de_emphasis)
                        tx_de_emphasis = pdata->tx_de_emphasis;
        }

        /* default to superspeed if no maximum_speed passed */
        if (dwc->maximum_speed == USB_SPEED_UNKNOWN)
                dwc->maximum_speed = USB_SPEED_SUPER;

        dwc->lpm_nyet_threshold = lpm_nyet_threshold;
        dwc->tx_de_emphasis = tx_de_emphasis;

        dwc->hird_threshold = hird_threshold
                | (dwc->is_utmi_l1_suspend << 4);

        platform_set_drvdata(pdev, dwc);
        dwc3_cache_hwparams(dwc);

        dwc3_phy_setup(dwc);

        ret = dwc3_core_get_phy(dwc);
        if (ret)
                goto err0;

        spin_lock_init(&dwc->lock);

        if (!dev->dma_mask) {
                dev->dma_mask = dev->parent->dma_mask;
                dev->dma_parms = dev->parent->dma_parms;
                dma_set_coherent_mask(dev, dev->parent->coherent_dma_mask);
        }

        pm_runtime_enable(dev);
        pm_runtime_get_sync(dev);
        pm_runtime_forbid(dev);

        ret = dwc3_alloc_event_buffers(dwc, DWC3_EVENT_BUFFERS_SIZE);
        if (ret) {
                dev_err(dwc->dev, "failed to allocate event buffers\n");
                ret = -ENOMEM;
                goto err1;
        }

        if (IS_ENABLED(CONFIG_USB_DWC3_HOST))
                dwc->dr_mode = USB_DR_MODE_HOST;
        else if (IS_ENABLED(CONFIG_USB_DWC3_GADGET))
                dwc->dr_mode = USB_DR_MODE_PERIPHERAL;

        if (dwc->dr_mode == USB_DR_MODE_UNKNOWN)
                dwc->dr_mode = USB_DR_MODE_OTG;

        ret = dwc3_core_init(dwc);
        if (ret) {
                dev_err(dev, "failed to initialize core\n");
                goto err1;
        }

        usb_phy_set_suspend(dwc->usb2_phy, 0);
        usb_phy_set_suspend(dwc->usb3_phy, 0);
        ret = phy_power_on(dwc->usb2_generic_phy);
        if (ret < 0)
                goto err2;

        ret = phy_power_on(dwc->usb3_generic_phy);
        if (ret < 0)
                goto err3;

        ret = dwc3_event_buffers_setup(dwc);
        if (ret) {
                dev_err(dwc->dev, "failed to setup event buffers\n");
                goto err4;
        }

        ret = dwc3_core_init_mode(dwc);
        if (ret)
                goto err5;

        ret = dwc3_debugfs_init(dwc);
        if (ret) {
                dev_err(dev, "failed to initialize debugfs\n");
                goto err6;
        }

        pm_runtime_allow(dev);

        return 0;

err6:
        dwc3_core_exit_mode(dwc);

err5:
        dwc3_event_buffers_cleanup(dwc);

err4:
        phy_power_off(dwc->usb3_generic_phy);

err3:
        phy_power_off(dwc->usb2_generic_phy);

err2:
        usb_phy_set_suspend(dwc->usb2_phy, 1);
        usb_phy_set_suspend(dwc->usb3_phy, 1);
        dwc3_core_exit(dwc);

err1:
        dwc3_free_event_buffers(dwc);

err0:
        /*
         * restore res->start back to its original value so that, in case the
         * probe is deferred, we don't end up getting error in request the
         * memory region the next time probe is called.
         */
        res->start -= DWC3_GLOBALS_REGS_START;

        return ret;
}

static int dwc3_remove(struct platform_device *pdev)
{
        struct dwc3     *dwc = platform_get_drvdata(pdev);
        struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

        /*
         * restore res->start back to its original value so that, in case the
         * probe is deferred, we don't end up getting error in request the
         * memory region the next time probe is called.
         */
        res->start -= DWC3_GLOBALS_REGS_START;

        dwc3_debugfs_exit(dwc);
        dwc3_core_exit_mode(dwc);
        dwc3_event_buffers_cleanup(dwc);
        dwc3_free_event_buffers(dwc);

        usb_phy_set_suspend(dwc->usb2_phy, 1);
        usb_phy_set_suspend(dwc->usb3_phy, 1);
        phy_power_off(dwc->usb2_generic_phy);
        phy_power_off(dwc->usb3_generic_phy);

        dwc3_core_exit(dwc);

        pm_runtime_put_sync(&pdev->dev);
        pm_runtime_disable(&pdev->dev);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int dwc3_suspend(struct device *dev)
{
        struct dwc3     *dwc = dev_get_drvdata(dev);
        unsigned long   flags;

        spin_lock_irqsave(&dwc->lock, flags);

        switch (dwc->dr_mode) {
        case USB_DR_MODE_PERIPHERAL:
        case USB_DR_MODE_OTG:
                dwc3_gadget_suspend(dwc);
                /* FALLTHROUGH */
        case USB_DR_MODE_HOST:
        default:
                dwc3_event_buffers_cleanup(dwc);
                break;
        }

        dwc->gctl = dwc3_readl(dwc->regs, DWC3_GCTL);
        spin_unlock_irqrestore(&dwc->lock, flags);

        usb_phy_shutdown(dwc->usb3_phy);
        usb_phy_shutdown(dwc->usb2_phy);
        phy_exit(dwc->usb2_generic_phy);
        phy_exit(dwc->usb3_generic_phy);

        return 0;
}

static int dwc3_resume(struct device *dev)
{
        struct dwc3     *dwc = dev_get_drvdata(dev);
        unsigned long   flags;
        int             ret;

        usb_phy_init(dwc->usb3_phy);
        usb_phy_init(dwc->usb2_phy);
        ret = phy_init(dwc->usb2_generic_phy);
        if (ret < 0)
                return ret;

        ret = phy_init(dwc->usb3_generic_phy);
        if (ret < 0)
                goto err_usb2phy_init;

        spin_lock_irqsave(&dwc->lock, flags);

        dwc3_event_buffers_setup(dwc);
        dwc3_writel(dwc->regs, DWC3_GCTL, dwc->gctl);

        switch (dwc->dr_mode) {
        case USB_DR_MODE_PERIPHERAL:
        case USB_DR_MODE_OTG:
                dwc3_gadget_resume(dwc);
                /* FALLTHROUGH */
        case USB_DR_MODE_HOST:
        default:
                /* do nothing */
                break;
        }

        spin_unlock_irqrestore(&dwc->lock, flags);

        pm_runtime_disable(dev);
        pm_runtime_set_active(dev);
        pm_runtime_enable(dev);

        return 0;

err_usb2phy_init:
        phy_exit(dwc->usb2_generic_phy);

        return ret;
}

static const struct dev_pm_ops dwc3_dev_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(dwc3_suspend, dwc3_resume)
};

#define DWC3_PM_OPS     &(dwc3_dev_pm_ops)
#else
#define DWC3_PM_OPS     NULL
#endif

#ifdef CONFIG_OF
static const struct of_device_id of_dwc3_match[] = {
        {
                .compatible = "snps,dwc3"
        },
        {
                .compatible = "synopsys,dwc3"
        },
        { },
};
MODULE_DEVICE_TABLE(of, of_dwc3_match);
#endif

#ifdef CONFIG_ACPI

#define ACPI_ID_INTEL_BSW       "808622B7"

static const struct acpi_device_id dwc3_acpi_match[] = {
        { ACPI_ID_INTEL_BSW, 0 },
        { },
};
MODULE_DEVICE_TABLE(acpi, dwc3_acpi_match);
#endif

static struct platform_driver dwc3_driver = {
        .probe          = dwc3_probe,
        .remove         = dwc3_remove,
        .driver         = {
                .name   = "dwc3",
                .of_match_table = of_match_ptr(of_dwc3_match),
                .acpi_match_table = ACPI_PTR(dwc3_acpi_match),
                .pm     = DWC3_PM_OPS,
        },
};

module_platform_driver(dwc3_driver);

MODULE_ALIAS("platform:dwc3");
MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("DesignWare USB3 DRD Controller Driver");