/**
 * 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/pinctrl/consumer.h>
#include <linux/of_address.h>

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

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

#include "debug.h"

#define DWC3_DEFAULT_AUTOSUSPEND_DELAY  5000 /* ms */

/**
 * dwc3_get_dr_mode - Validates and sets dr_mode
 * @dwc: pointer to our context structure
 */
static int dwc3_get_dr_mode(struct dwc3 *dwc)
{
        enum usb_dr_mode mode;
        struct device *dev = dwc->dev;
        unsigned int hw_mode;

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

        mode = dwc->dr_mode;
        hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);

        switch (hw_mode) {
        case DWC3_GHWPARAMS0_MODE_GADGET:
                if (IS_ENABLED(CONFIG_USB_DWC3_HOST)) {
                        dev_err(dev,
                                "Controller does not support host mode.\n");
                        return -EINVAL;
                }
                mode = USB_DR_MODE_PERIPHERAL;
                break;
        case DWC3_GHWPARAMS0_MODE_HOST:
                if (IS_ENABLED(CONFIG_USB_DWC3_GADGET)) {
                        dev_err(dev,
                                "Controller does not support device mode.\n");
                        return -EINVAL;
                }
                mode = USB_DR_MODE_HOST;
                break;
        default:
                if (IS_ENABLED(CONFIG_USB_DWC3_HOST))
                        mode = USB_DR_MODE_HOST;
                else if (IS_ENABLED(CONFIG_USB_DWC3_GADGET))
                        mode = USB_DR_MODE_PERIPHERAL;
        }

        if (mode != dwc->dr_mode) {
                dev_warn(dev,
                         "Configuration mismatch. dr_mode forced to %s\n",
                         mode == USB_DR_MODE_HOST ? "host" : "gadget");

                dwc->dr_mode = mode;
        }

        return 0;
}

static void dwc3_event_buffers_cleanup(struct dwc3 *dwc);

static void dwc3_set_prtcap(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);
}

static void __dwc3_set_mode(struct work_struct *work)
{
        struct dwc3 *dwc = work_to_dwc(work);
        unsigned long flags;
        int ret;

        if (!dwc->desired_dr_role)
                return;

        if (dwc->desired_dr_role == dwc->current_dr_role)
                return;

        if (dwc->dr_mode != USB_DR_MODE_OTG)
                return;

        switch (dwc->current_dr_role) {
        case DWC3_GCTL_PRTCAP_HOST:
                dwc3_host_exit(dwc);
                break;
        case DWC3_GCTL_PRTCAP_DEVICE:
                dwc3_gadget_exit(dwc);
                dwc3_event_buffers_cleanup(dwc);
                break;
        default:
                break;
        }

        spin_lock_irqsave(&dwc->lock, flags);

        dwc3_set_prtcap(dwc, dwc->desired_dr_role);

        dwc->current_dr_role = dwc->desired_dr_role;

        spin_unlock_irqrestore(&dwc->lock, flags);

        switch (dwc->desired_dr_role) {
        case DWC3_GCTL_PRTCAP_HOST:
                ret = dwc3_host_init(dwc);
                if (ret) {
                        dev_err(dwc->dev, "failed to initialize host\n");
                } else {
                        if (dwc->usb2_phy)
                                otg_set_vbus(dwc->usb2_phy->otg, true);
                        if (dwc->usb2_generic_phy)
                                phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);

                }
                break;
        case DWC3_GCTL_PRTCAP_DEVICE:
                dwc3_event_buffers_setup(dwc);

                if (dwc->usb2_phy)
                        otg_set_vbus(dwc->usb2_phy->otg, false);
                if (dwc->usb2_generic_phy)
                        phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_DEVICE);

                ret = dwc3_gadget_init(dwc);
                if (ret)
                        dev_err(dwc->dev, "failed to initialize peripheral\n");
                break;
        default:
                break;
        }
}

void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
{
        unsigned long flags;

        spin_lock_irqsave(&dwc->lock, flags);
        dwc->desired_dr_role = mode;
        spin_unlock_irqrestore(&dwc->lock, flags);

        queue_work(system_power_efficient_wq, &dwc->drd_work);
}

u32 dwc3_core_fifo_space(struct dwc3_ep *dep, u8 type)
{
        struct dwc3             *dwc = dep->dwc;
        u32                     reg;

        dwc3_writel(dwc->regs, DWC3_GDBGFIFOSPACE,
                        DWC3_GDBGFIFOSPACE_NUM(dep->number) |
                        DWC3_GDBGFIFOSPACE_TYPE(type));

        reg = dwc3_readl(dwc->regs, DWC3_GDBGFIFOSPACE);

        return DWC3_GDBGFIFOSPACE_SPACE_AVAILABLE(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             retries = 1000;
        int             ret;

        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;
        }

        /*
         * We're resetting only the device side because, if we're in host mode,
         * XHCI driver will reset the host block. If dwc3 was configured for
         * host-only mode, then we can return early.
         */
        if (dwc->dr_mode == USB_DR_MODE_HOST || dwc->is_hibernated == true)
                return 0;

        reg = dwc3_readl(dwc->regs, DWC3_DCTL);
        reg |= DWC3_DCTL_CSFTRST;
        dwc3_writel(dwc->regs, DWC3_DCTL, reg);

        do {
                reg = dwc3_readl(dwc->regs, DWC3_DCTL);
                if (!(reg & DWC3_DCTL_CSFTRST))
                        return 0;

                udelay(1);
        } while (--retries);

        return -ETIMEDOUT;
}

/*
 * dwc3_frame_length_adjustment - Adjusts frame length if required
 * @dwc3: Pointer to our controller context structure
 */
static void dwc3_frame_length_adjustment(struct dwc3 *dwc)
{
        u32 reg, gfladj;
        u32 dft;

        if (dwc->revision < DWC3_REVISION_250A)
                return;

        if (dwc->fladj == 0)
                return;

        /* Save the initial DWC3_GFLADJ register value */
        reg = dwc3_readl(dwc->regs, DWC3_GFLADJ);
        gfladj = reg;

        if (dwc->refclk_fladj) {
                if ((reg & DWC3_GFLADJ_REFCLK_FLADJ) !=
                                    (dwc->fladj & DWC3_GFLADJ_REFCLK_FLADJ)) {
                        reg &= ~DWC3_GFLADJ_REFCLK_FLADJ;
                        reg |= (dwc->fladj & DWC3_GFLADJ_REFCLK_FLADJ);
                }
        }

        dft = reg & DWC3_GFLADJ_30MHZ_MASK;
        if (dft != dwc->fladj) {
                reg &= ~DWC3_GFLADJ_30MHZ_MASK;
                reg |= DWC3_GFLADJ_30MHZ_SDBND_SEL | dwc->fladj;
        }

        /* Update DWC3_GFLADJ if there is any change from initial value */
        if (reg != gfladj)
                dwc3_writel(dwc->regs, DWC3_GFLADJ, reg);
}

/**
 * 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->sysdev, 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->cache      = devm_kzalloc(dwc->dev, length, GFP_KERNEL);
        if (!evt->cache)
                return ERR_PTR(-ENOMEM);

        evt->buf        = dma_alloc_coherent(dwc->sysdev, 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
 */
void dwc3_free_event_buffers(struct dwc3 *dwc)
{
        struct dwc3_event_buffer        *evt;

        evt = dwc->ev_buf;
        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.
 */
int dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned length)
{
        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_buf = 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.
 */
int dwc3_event_buffers_setup(struct dwc3 *dwc)
{
        struct dwc3_event_buffer        *evt;

        if (dwc->dr_mode == USB_DR_MODE_HOST)
                return 0;

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

        return 0;
}

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

        evt = dwc->ev_buf;

        evt->lpos = 0;

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

static int dwc3_alloc_scratch_buffers(struct dwc3 *dwc)
{
        u32 size;

        if (dwc->dr_mode == USB_DR_MODE_HOST)
                return 0;

        if (!dwc->has_hibernation)
                return 0;

        if (!dwc->nr_scratch)
                return 0;

        /* Allocate only if scratchbuf is NULL */
        if (dwc->scratchbuf)
                return 0;

        size = dwc->nr_scratch * DWC3_SCRATCHBUF_SIZE;

        dwc->scratchbuf = kzalloc(size, GFP_KERNEL);

        if (!dwc->scratchbuf)
                return -ENOMEM;

        dwc->scratch_addr = dma_map_single(dwc->dev, dwc->scratchbuf, size,
                                           DMA_BIDIRECTIONAL);
        if (dma_mapping_error(dwc->dev, dwc->scratch_addr)) {
                dev_err(dwc->dev, "failed to map scratch buffer\n");
                return -EFAULT;
        }

        return 0;
}

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

        if (dwc->dr_mode == USB_DR_MODE_HOST)
                return 0;

        if (!dwc->has_hibernation)
                return 0;

        if (!dwc->nr_scratch)
                return 0;

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

        param = lower_32_bits(dwc->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(dwc->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->sysdev, dwc->scratch_addr, dwc->nr_scratch *
                        DWC3_SCRATCHBUF_SIZE, DMA_BIDIRECTIONAL);

        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->sysdev, 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_eps = DWC3_NUM_EPS(parms);
}

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);
}

static int dwc3_config_soc_bus(struct dwc3 *dwc)
{
        int ret;

        /*
         * Check if CCI is enabled for USB. Returns true
         * if the node has property 'dma-coherent'. Otherwise
         * returns false.
         */
        if (of_dma_is_coherent(dwc->dev->of_node)) {
                u32 reg;

                reg = dwc3_readl(dwc->regs, DWC3_GSBUSCFG0);
                reg |= DWC3_GSBUSCFG0_DATRDREQINFO |
                        DWC3_GSBUSCFG0_DESRDREQINFO |
                        DWC3_GSBUSCFG0_DATWRREQINFO |
                        DWC3_GSBUSCFG0_DESWRREQINFO;
                dwc3_writel(dwc->regs, DWC3_GSBUSCFG0, reg);

                ret = dwc3_enable_hw_coherency(dwc->dev);
                if (ret)
                        return ret;
        }

        /* Send struct dwc3 to dwc3-of-simple for configuring VBUS
         * during suspend/resume
         */
        dwc3_set_simple_data(dwc);

        return 0;
}

/**
 * dwc3_phy_setup - Configure USB PHY Interface of DWC3 Core
 * @dwc: Pointer to our controller context structure
 *
 * Returns 0 on success. The USB PHY interfaces are configured but not
 * initialized. The PHY interfaces and the PHYs get initialized together with
 * the core in dwc3_core_init.
 */
static int dwc3_phy_setup(struct dwc3 *dwc)
{
        u32 reg;
        int ret;

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

        /*
         * Make sure UX_EXIT_PX is cleared as that causes issues with some
         * PHYs. Also, this bit is not supposed to be used in normal operation.
         */
        reg &= ~DWC3_GUSB3PIPECTL_UX_EXIT_PX;

        /*
         * 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->dis_rxdet_inp3_quirk)
                reg |= DWC3_GUSB3PIPECTL_DISRXDETINP3;

        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;

        if (dwc->dis_del_phy_power_chg_quirk)
                reg &= ~DWC3_GUSB3PIPECTL_DEPOCHANGE;

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

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

        /* Select the HS PHY interface */
        switch (DWC3_GHWPARAMS3_HSPHY_IFC(dwc->hwparams.hwparams3)) {
        case DWC3_GHWPARAMS3_HSPHY_IFC_UTMI_ULPI:
                if (dwc->hsphy_interface &&
                                !strncmp(dwc->hsphy_interface, "utmi", 4)) {
                        reg &= ~DWC3_GUSB2PHYCFG_ULPI_UTMI;
                        break;
                } else if (dwc->hsphy_interface &&
                                !strncmp(dwc->hsphy_interface, "ulpi", 4)) {
                        reg |= DWC3_GUSB2PHYCFG_ULPI_UTMI;
                        dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
                } else {
                        /* Relying on default value. */
                        if (!(reg & DWC3_GUSB2PHYCFG_ULPI_UTMI))
                                break;
                }
                /* FALLTHROUGH */
        case DWC3_GHWPARAMS3_HSPHY_IFC_ULPI:
                ret = dwc3_ulpi_init(dwc);
                if (ret)
                        return ret;
                /* FALLTHROUGH */
        default:
                break;
        }

        switch (dwc->hsphy_mode) {
        case USBPHY_INTERFACE_MODE_UTMI:
                reg &= ~(DWC3_GUSB2PHYCFG_PHYIF_MASK |
                       DWC3_GUSB2PHYCFG_USBTRDTIM_MASK);
                reg |= DWC3_GUSB2PHYCFG_PHYIF(UTMI_PHYIF_8_BIT) |
                       DWC3_GUSB2PHYCFG_USBTRDTIM(USBTRDTIM_UTMI_8_BIT);
                break;
        case USBPHY_INTERFACE_MODE_UTMIW:
                reg &= ~(DWC3_GUSB2PHYCFG_PHYIF_MASK |
                       DWC3_GUSB2PHYCFG_USBTRDTIM_MASK);
                reg |= DWC3_GUSB2PHYCFG_PHYIF(UTMI_PHYIF_16_BIT) |
                       DWC3_GUSB2PHYCFG_USBTRDTIM(USBTRDTIM_UTMI_16_BIT);
                break;
        default:
                break;
        }

        /*
         * 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;

        if (dwc->dis_enblslpm_quirk)
                reg &= ~DWC3_GUSB2PHYCFG_ENBLSLPM;

        if (dwc->dis_u2_freeclk_exists_quirk)
                reg &= ~DWC3_GUSB2PHYCFG_U2_FREECLK_EXISTS;

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

        return 0;
}

static void dwc3_core_exit(struct dwc3 *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);

        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);
}

static bool dwc3_core_is_valid(struct dwc3 *dwc)
{
        u32 reg;

        reg = dwc3_readl(dwc->regs, DWC3_GSNPSID);

        /* This should read as U3 followed by revision number */
        if ((reg & DWC3_GSNPSID_MASK) == 0x55330000) {
                /* Detected DWC_usb3 IP */
                dwc->revision = reg;
        } else if ((reg & DWC3_GSNPSID_MASK) == 0x33310000) {
                /* Detected DWC_usb31 IP */
                dwc->revision = dwc3_readl(dwc->regs, DWC3_VER_NUMBER);
                dwc->revision |= DWC3_REVISION_IS_DWC31;
        } else {
                return false;
        }

        return true;
}

static void dwc3_core_setup_global_control(struct dwc3 *dwc)
{
        u32 hwparams4 = dwc->hwparams.hwparams4;
        u32 reg;

        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:
                if (!device_property_read_bool(dwc->dev,
                                               "snps,enable-hibernation")) {
                        dev_dbg(dwc->dev, "Hibernation not enabled\n");
                } else {
                        /* enable hibernation here */
                        dwc->nr_scratch =
                                DWC3_GHWPARAMS4_HIBER_SCRATCHBUFS(hwparams4);
                        dwc->has_hibernation = 1;
                }

                /*
                 * REVISIT Enabling this bit so that host-mode hibernation
                 * will work. Device-mode hibernation is not yet implemented.
                 */
                reg |= DWC3_GCTL_GBLHIBERNATIONEN;
                break;
        default:
                /* nothing */
                break;
        }

        /* check if current dwc3 is on simulation board */
        if (dwc->hwparams.hwparams6 & DWC3_GHWPARAMS6_EN_FPGA) {
                dev_info(dwc->dev, "Running with FPGA optmizations\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_writel(dwc->regs, DWC3_GCTL, reg);
}

static int dwc3_core_get_phy(struct dwc3 *dwc);

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

        if (!dwc3_core_is_valid(dwc)) {
                dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n");
                ret = -ENODEV;
                goto err0;
        }

        /*
         * 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;
        }

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

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

        ret = dwc3_config_soc_bus(dwc);
        if (ret)
                goto err0;

        ret = dwc3_phy_setup(dwc);
        if (ret)
                goto err0;

        dwc3_core_setup_global_control(dwc);
        dwc3_core_num_eps(dwc);

        if (dwc->scratchbuf == NULL) {
                ret = dwc3_alloc_scratch_buffers(dwc);
                if (ret) {
                        dev_err(dwc->dev,
                                "Not enough memory for scratch buffers\n");
                        goto err1;
                }
        }

        ret = dwc3_setup_scratch_buffers(dwc);
        if (ret) {
                dev_err(dwc->dev, "Failed to setup scratch buffers: %d\n", ret);
                goto err1;
        }

        /* Adjust Frame Length */
        dwc3_frame_length_adjustment(dwc);

        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;
        }

        switch (dwc->dr_mode) {
        case USB_DR_MODE_PERIPHERAL:
                dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE);
                break;
        case USB_DR_MODE_HOST:
                dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
                break;
        case USB_DR_MODE_OTG:
                dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG);
                break;
        default:
                dev_warn(dwc->dev, "Unsupported mode %d\n", dwc->dr_mode);
                break;
        }

        /*
         * ENDXFER polling is available on version 3.10a and later of
         * the DWC_usb3 controller. It is NOT available in the
         * DWC_usb31 controller.
         */
        if (!dwc3_is_usb31(dwc) && dwc->revision >= DWC3_REVISION_310A) {
                reg = dwc3_readl(dwc->regs, DWC3_GUCTL2);
                reg |= DWC3_GUCTL2_RST_ACTBITLATER;
                dwc3_writel(dwc->regs, DWC3_GUCTL2, reg);
        }

        /* When configured in HOST mode, after issuing U3/L2 exit controller
         * fails to send proper CRC checksum in CRC5 feild. Because of this
         * behaviour Transaction Error is generated, resulting in reset and
         * re-enumeration of usb device attached. Enabling bit 10 of GUCTL1
         * will correct this problem
         */
        if (dwc->enable_guctl1_resume_quirk) {
                reg = dwc3_readl(dwc->regs, DWC3_GUCTL1);
                reg |= DWC3_GUCTL1_RESUME_QUIRK;
                dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
        }

        /* SNPS controller when configureed in HOST mode maintains Inter Packet
         * Delay (IPD) of ~380ns which works with most of the super-speed hubs
         * except VIA-LAB hubs. When IPD is ~380ns HOST controller fails to
         * enumerate FS/LS devices when connected behind VIA-LAB hubs.
         * Enabling bit 9 of GUCTL1 enables the workaround in HW to reduce the
         * ULPI clock latency by 1 cycle, thus reducing the IPD (~360ns) and
         * making controller enumerate FS/LS devices connected behind VIA-LAB.
         */
        if (dwc->enable_guctl1_ipd_quirk) {
                reg = dwc3_readl(dwc->regs, DWC3_GUCTL1);
                reg |= DWC3_GUCTL1_IPD_QUIRK;
                dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
        }

        if (dwc->revision >= DWC3_REVISION_250A) {
                reg = dwc3_readl(dwc->regs, DWC3_GUCTL1);

                /*
                 * Enable hardware control of sending remote wakeup
                 * in HS when the device is in the L1 state.
                 */
                if (dwc->revision >= DWC3_REVISION_290A)
                        reg |= DWC3_GUCTL1_DEV_L1_EXIT_BY_HW;

                if (dwc->dis_tx_ipgap_linecheck_quirk)
                        reg |= DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS;

                dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
        }

        return 0;

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);

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 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_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE);

                if (dwc->usb2_phy)
                        otg_set_vbus(dwc->usb2_phy->otg, false);
                if (dwc->usb2_generic_phy)
                        phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_DEVICE);

                ret = dwc3_gadget_init(dwc);
                if (ret) {
                        if (ret != -EPROBE_DEFER)
                                dev_err(dev, "failed to initialize gadget\n");
                        return ret;
                }
                break;
        case USB_DR_MODE_HOST:
                dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);

                if (dwc->usb2_phy)
                        otg_set_vbus(dwc->usb2_phy->otg, true);
                if (dwc->usb2_generic_phy)
                        phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);

                ret = dwc3_host_init(dwc);
                if (ret) {
                        if (ret != -EPROBE_DEFER)
                                dev_err(dev, "failed to initialize host\n");
                        return ret;
                }
                break;
        case USB_DR_MODE_OTG:
                dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG);

                ret = dwc3_otg_init(dwc);
                if (ret) {
                        if (ret != -EPROBE_DEFER)
                                dev_err(dev, "failed to initialize otg\n");
                        return ret;
                }

                ret = dwc3_gadget_init(dwc);
                if (ret) {
                        if (ret != -EPROBE_DEFER)
                                dev_err(dev, "failed to initialize gadget\n");
                        return ret;
                }

                ret = dwc3_host_init(dwc);
                if (ret) {
                        if (ret != -EPROBE_DEFER)
                                dev_err(dev, "failed to initialize host\n");
                        return ret;
                }

                INIT_WORK(&dwc->drd_work, __dwc3_set_mode);
                ret = dwc3_drd_init(dwc);
                if (ret) {
                        if (ret != -EPROBE_DEFER)
                                dev_err(dev, "failed to initialize dual-role\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_drd_exit(dwc);
                break;
        default:
                /* do nothing */
                break;
        }
}

static void dwc3_get_properties(struct dwc3 *dwc)
{
        struct device           *dev = dwc->dev;
        u8                      lpm_nyet_threshold;
        u8                      tx_de_emphasis;
        u8                      hird_threshold;

        /* 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;

        dwc->maximum_speed = usb_get_maximum_speed(dev);
        dwc->dr_mode = usb_get_dr_mode(dev);
        dwc->hsphy_mode = of_usb_get_phy_mode(dev->of_node);

        dwc->sysdev_is_parent = device_property_read_bool(dev,
                                "linux,sysdev_is_parent");
        if (dwc->sysdev_is_parent)
                dwc->sysdev = dwc->dev->parent;
        else
                dwc->sysdev = dwc->dev;

        dwc->has_lpm_erratum = device_property_read_bool(dev,
                                "snps,has-lpm-erratum");
        device_property_read_u8(dev, "snps,lpm-nyet-threshold",
                                &lpm_nyet_threshold);
        dwc->is_utmi_l1_suspend = device_property_read_bool(dev,
                                "snps,is-utmi-l1-suspend");
        device_property_read_u8(dev, "snps,hird-threshold",
                                &hird_threshold);
        dwc->usb3_lpm_capable = device_property_read_bool(dev,
                                "snps,usb3_lpm_capable");

        dwc->disable_scramble_quirk = device_property_read_bool(dev,
                                "snps,disable_scramble_quirk");
        dwc->u2exit_lfps_quirk = device_property_read_bool(dev,
                                "snps,u2exit_lfps_quirk");
        dwc->u2ss_inp3_quirk = device_property_read_bool(dev,
                                "snps,u2ss_inp3_quirk");
        dwc->req_p1p2p3_quirk = device_property_read_bool(dev,
                                "snps,req_p1p2p3_quirk");
        dwc->del_p1p2p3_quirk = device_property_read_bool(dev,
                                "snps,del_p1p2p3_quirk");
        dwc->del_phy_power_chg_quirk = device_property_read_bool(dev,
                                "snps,del_phy_power_chg_quirk");
        dwc->lfps_filter_quirk = device_property_read_bool(dev,
                                "snps,lfps_filter_quirk");
        dwc->rx_detect_poll_quirk = device_property_read_bool(dev,
                                "snps,rx_detect_poll_quirk");
        dwc->dis_u3_susphy_quirk = device_property_read_bool(dev,
                                "snps,dis_u3_susphy_quirk");
        dwc->dis_u2_susphy_quirk = device_property_read_bool(dev,
                                "snps,dis_u2_susphy_quirk");
        dwc->dis_enblslpm_quirk = device_property_read_bool(dev,
                                "snps,dis_enblslpm_quirk");
        dwc->dis_rxdet_inp3_quirk = device_property_read_bool(dev,
                                "snps,dis_rxdet_inp3_quirk");
        dwc->dis_u2_freeclk_exists_quirk = device_property_read_bool(dev,
                                "snps,dis-u2-freeclk-exists-quirk");
        dwc->dis_del_phy_power_chg_quirk = device_property_read_bool(dev,
                                "snps,dis-del-phy-power-chg-quirk");
        dwc->dis_tx_ipgap_linecheck_quirk = device_property_read_bool(dev,
                                "snps,dis-tx-ipgap-linecheck-quirk");

        dwc->tx_de_emphasis_quirk = device_property_read_bool(dev,
                                "snps,tx_de_emphasis_quirk");
        device_property_read_u8(dev, "snps,tx_de_emphasis",
                                &tx_de_emphasis);
        device_property_read_string(dev, "snps,hsphy_interface",
                                    &dwc->hsphy_interface);
        device_property_read_u32(dev, "snps,quirk-frame-length-adjustment",
                                 &dwc->fladj);

        dwc->refclk_fladj = device_property_read_bool(dev,
                                                      "snps,refclk_fladj");
        dwc->enable_guctl1_resume_quirk = device_property_read_bool(dev,
                                "snps,enable_guctl1_resume_quirk");
        dwc->enable_guctl1_ipd_quirk = device_property_read_bool(dev,
                                "snps,enable_guctl1_ipd_quirk");

        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);

        /* Check if extra quirks to be added */
        dwc3_simple_check_quirks(dwc);

        dwc->imod_interval = 0;
}

/* check whether the core supports IMOD */
bool dwc3_has_imod(struct dwc3 *dwc)
{
        return ((dwc3_is_usb3(dwc) &&
                 dwc->revision >= DWC3_REVISION_300A) ||
                (dwc3_is_usb31(dwc) &&
                 dwc->revision >= DWC3_USB31_REVISION_120A));
}

static void dwc3_check_params(struct dwc3 *dwc)
{
        struct device *dev = dwc->dev;

        /* Check for proper value of imod_interval */
        if (dwc->imod_interval && !dwc3_has_imod(dwc)) {
                dev_warn(dwc->dev, "Interrupt moderation not supported\n");
                dwc->imod_interval = 0;
        }

        /*
         * Workaround for STAR 9000961433 which affects only version
         * 3.00a of the DWC_usb3 core. This prevents the controller
         * interrupt from being masked while handling events. IMOD
         * allows us to work around this issue. Enable it for the
         * affected version.
         */
        if (!dwc->imod_interval &&
            (dwc->revision == DWC3_REVISION_300A))
                dwc->imod_interval = 1;

        /* Check the maximum_speed parameter */
        switch (dwc->maximum_speed) {
        case USB_SPEED_LOW:
        case USB_SPEED_FULL:
        case USB_SPEED_HIGH:
        case USB_SPEED_SUPER:
        case USB_SPEED_SUPER_PLUS:
                break;
        default:
                dev_err(dev, "invalid maximum_speed parameter %d\n",
                        dwc->maximum_speed);
                /* fall through */
        case USB_SPEED_UNKNOWN:
                /* default to superspeed */
                dwc->maximum_speed = USB_SPEED_SUPER;

                /*
                 * default to superspeed plus if we are capable.
                 */
                if (dwc3_is_usb31(dwc) &&
                    (DWC3_GHWPARAMS3_SSPHY_IFC(dwc->hwparams.hwparams3) ==
                     DWC3_GHWPARAMS3_SSPHY_IFC_GEN2))
                        dwc->maximum_speed = USB_SPEED_SUPER_PLUS;

                break;
        }
}

static int dwc3_probe(struct platform_device *pdev)
{
        struct device           *dev = &pdev->dev;
        struct resource         *res;
        struct dwc3             *dwc;
        int                     ret;
        u32                     mdwidth;
        void __iomem            *regs;

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

        dwc->dev = dev;

        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);

        dwc3_get_properties(dwc);

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

        spin_lock_init(&dwc->lock);

        /* Set dma coherent mask to DMA BUS data width */
        mdwidth = DWC3_GHWPARAMS0_MDWIDTH(dwc->hwparams.hwparams0);
        dev_dbg(dev, "Enabling %d-bit DMA addresses.\n", mdwidth);
        dma_set_coherent_mask(dev, DMA_BIT_MASK(mdwidth));

        pm_runtime_set_active(dev);
        pm_runtime_use_autosuspend(dev);
        pm_runtime_set_autosuspend_delay(dev, DWC3_DEFAULT_AUTOSUSPEND_DELAY);
        pm_runtime_enable(dev);
        ret = pm_runtime_get_sync(dev);
        if (ret < 0)
                goto err1;

        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 err2;
        }

        ret = dwc3_get_dr_mode(dwc);
        if (ret)
                goto err3;

        ret = dwc3_core_init(dwc);
        if (ret) {
                dev_err(dev, "failed to initialize core\n");
                goto err4;
        }

        dwc3_check_params(dwc);

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

        dwc3_debugfs_init(dwc);
        pm_runtime_put(dev);

        return 0;

err5:
        dwc3_event_buffers_cleanup(dwc);

err4:
        dwc3_free_scratch_buffers(dwc);

err3:
        dwc3_free_event_buffers(dwc);
        dwc3_ulpi_exit(dwc);

err2:
        pm_runtime_allow(&pdev->dev);

err1:
        pm_runtime_put_sync(&pdev->dev);
        pm_runtime_disable(&pdev->dev);

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);

        pm_runtime_get_sync(&pdev->dev);
        /*
         * 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_core_exit(dwc);
        dwc3_ulpi_exit(dwc);

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

        dwc3_free_event_buffers(dwc);
        dwc3_free_scratch_buffers(dwc);

        return 0;
}

#ifdef CONFIG_PM
static int dwc3_suspend_common(struct dwc3 *dwc)
{
        unsigned long   flags;

        switch (dwc->dr_mode) {
        case USB_DR_MODE_PERIPHERAL:
        case USB_DR_MODE_OTG:
                spin_lock_irqsave(&dwc->lock, flags);
                dwc3_gadget_suspend(dwc);
                spin_unlock_irqrestore(&dwc->lock, flags);
                break;
        case USB_DR_MODE_HOST:
        default:
                /* do nothing */
                break;
        }

        dwc3_event_buffers_cleanup(dwc);

        /* Put the core into D3 state */
        dwc3_set_usb_core_power(dwc, false);

        /*
         * To avoid reinit of phy during resume, prevent calling the
         * dwc3_core_exit() when in D3 state
         */
        if (!dwc->is_d3)
                dwc3_core_exit(dwc);

        return 0;
}

static int dwc3_resume_common(struct dwc3 *dwc)
{
        unsigned long   flags;
        int             ret;

        /* Bring core to D0 state */
        dwc3_set_usb_core_power(dwc, true);

        ret = dwc3_core_init(dwc);
        if (ret)
                return ret;

        switch (dwc->dr_mode) {
        case USB_DR_MODE_PERIPHERAL:
        case USB_DR_MODE_OTG:
                spin_lock_irqsave(&dwc->lock, flags);
                dwc3_gadget_resume(dwc);
                spin_unlock_irqrestore(&dwc->lock, flags);
                /* FALLTHROUGH */
        case USB_DR_MODE_HOST:
        default:
                /* do nothing */
                break;
        }

        return 0;
}

static int dwc3_runtime_checks(struct dwc3 *dwc)
{
        switch (dwc->dr_mode) {
        case USB_DR_MODE_PERIPHERAL:
        case USB_DR_MODE_OTG:
                if (dwc->connected)
                        return -EBUSY;
                break;
        case USB_DR_MODE_HOST:
        default:
                /* do nothing */
                break;
        }

        return 0;
}

static int dwc3_runtime_suspend(struct device *dev)
{
        struct dwc3     *dwc = dev_get_drvdata(dev);
        int             ret;

        if (dwc3_runtime_checks(dwc))
                return -EBUSY;

        ret = dwc3_suspend_common(dwc);
        if (ret)
                return ret;

        device_init_wakeup(dev, true);

        return 0;
}

static int dwc3_runtime_resume(struct device *dev)
{
        struct dwc3     *dwc = dev_get_drvdata(dev);
        int             ret;

        device_init_wakeup(dev, false);

        ret = dwc3_resume_common(dwc);
        if (ret)
                return ret;

        switch (dwc->dr_mode) {
        case USB_DR_MODE_PERIPHERAL:
        case USB_DR_MODE_OTG:
                dwc3_gadget_process_pending_events(dwc);
                break;
        case USB_DR_MODE_HOST:
        default:
                /* do nothing */
                break;
        }

        pm_runtime_mark_last_busy(dev);
        pm_runtime_put(dev);

        return 0;
}

static int dwc3_runtime_idle(struct device *dev)
{
        struct dwc3     *dwc = dev_get_drvdata(dev);

        switch (dwc->dr_mode) {
        case USB_DR_MODE_PERIPHERAL:
        case USB_DR_MODE_OTG:
                if (dwc3_runtime_checks(dwc))
                        return -EBUSY;
                break;
        case USB_DR_MODE_HOST:
        default:
                /* do nothing */
                break;
        }

        pm_runtime_mark_last_busy(dev);
        pm_runtime_autosuspend(dev);

        return 0;
}
#endif /* CONFIG_PM */

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

        ret = dwc3_suspend_common(dwc);
        if (ret)
                return ret;

        pinctrl_pm_select_sleep_state(dev);

        return 0;
}

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

        pinctrl_pm_select_default_state(dev);

        ret = dwc3_resume_common(dwc);
        if (ret)
                return ret;

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

        return 0;
}
#endif /* CONFIG_PM_SLEEP */

static const struct dev_pm_ops dwc3_dev_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(dwc3_suspend, dwc3_resume)
        SET_RUNTIME_PM_OPS(dwc3_runtime_suspend, dwc3_runtime_resume,
                        dwc3_runtime_idle)
};

#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_dev_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");