// SPDX-License-Identifier: GPL-2.0
/*
 * core.c - ChipIdea USB IP core family device controller
 *
 * Copyright (C) 2008 Chipidea - MIPS Technologies, Inc. All rights reserved.
 *
 * Author: David Lopo
 */

/*
 * Description: ChipIdea USB IP core family device controller
 *
 * This driver is composed of several blocks:
 * - HW:     hardware interface
 * - DBG:    debug facilities (optional)
 * - UTIL:   utilities
 * - ISR:    interrupts handling
 * - ENDPT:  endpoint operations (Gadget API)
 * - GADGET: gadget operations (Gadget API)
 * - BUS:    bus glue code, bus abstraction layer
 *
 * Compile Options
 * - STALL_IN:  non-empty bulk-in pipes cannot be halted
 *              if defined mass storage compliance succeeds but with warnings
 *              => case 4: Hi >  Dn
 *              => case 5: Hi >  Di
 *              => case 8: Hi <> Do
 *              if undefined usbtest 13 fails
 * - TRACE:     enable function tracing (depends on DEBUG)
 *
 * Main Features
 * - Chapter 9 & Mass Storage Compliance with Gadget File Storage
 * - Chapter 9 Compliance with Gadget Zero (STALL_IN undefined)
 * - Normal & LPM support
 *
 * USBTEST Report
 * - OK: 0-12, 13 (STALL_IN defined) & 14
 * - Not Supported: 15 & 16 (ISO)
 *
 * TODO List
 * - Suspend & Remote Wakeup
 */
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/extcon.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/otg.h>
#include <linux/usb/chipidea.h>
#include <linux/usb/of.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>
#include <linux/usb/ehci_def.h>

#include "ci.h"
#include "udc.h"
#include "bits.h"
#include "host.h"
#include "otg.h"
#include "otg_fsm.h"

/* Controller register map */
static const u8 ci_regs_nolpm[] = {
        [CAP_CAPLENGTH]         = 0x00U,
        [CAP_HCCPARAMS]         = 0x08U,
        [CAP_DCCPARAMS]         = 0x24U,
        [CAP_TESTMODE]          = 0x38U,
        [OP_USBCMD]             = 0x00U,
        [OP_USBSTS]             = 0x04U,
        [OP_USBINTR]            = 0x08U,
        [OP_DEVICEADDR]         = 0x14U,
        [OP_ENDPTLISTADDR]      = 0x18U,
        [OP_TTCTRL]             = 0x1CU,
        [OP_BURSTSIZE]          = 0x20U,
        [OP_ULPI_VIEWPORT]      = 0x30U,
        [OP_PORTSC]             = 0x44U,
        [OP_DEVLC]              = 0x84U,
        [OP_OTGSC]              = 0x64U,
        [OP_USBMODE]            = 0x68U,
        [OP_ENDPTSETUPSTAT]     = 0x6CU,
        [OP_ENDPTPRIME]         = 0x70U,
        [OP_ENDPTFLUSH]         = 0x74U,
        [OP_ENDPTSTAT]          = 0x78U,
        [OP_ENDPTCOMPLETE]      = 0x7CU,
        [OP_ENDPTCTRL]          = 0x80U,
};

static const u8 ci_regs_lpm[] = {
        [CAP_CAPLENGTH]         = 0x00U,
        [CAP_HCCPARAMS]         = 0x08U,
        [CAP_DCCPARAMS]         = 0x24U,
        [CAP_TESTMODE]          = 0xFCU,
        [OP_USBCMD]             = 0x00U,
        [OP_USBSTS]             = 0x04U,
        [OP_USBINTR]            = 0x08U,
        [OP_DEVICEADDR]         = 0x14U,
        [OP_ENDPTLISTADDR]      = 0x18U,
        [OP_TTCTRL]             = 0x1CU,
        [OP_BURSTSIZE]          = 0x20U,
        [OP_ULPI_VIEWPORT]      = 0x30U,
        [OP_PORTSC]             = 0x44U,
        [OP_DEVLC]              = 0x84U,
        [OP_OTGSC]              = 0xC4U,
        [OP_USBMODE]            = 0xC8U,
        [OP_ENDPTSETUPSTAT]     = 0xD8U,
        [OP_ENDPTPRIME]         = 0xDCU,
        [OP_ENDPTFLUSH]         = 0xE0U,
        [OP_ENDPTSTAT]          = 0xE4U,
        [OP_ENDPTCOMPLETE]      = 0xE8U,
        [OP_ENDPTCTRL]          = 0xECU,
};

static void hw_alloc_regmap(struct ci_hdrc *ci, bool is_lpm)
{
        int i;

        for (i = 0; i < OP_ENDPTCTRL; i++)
                ci->hw_bank.regmap[i] =
                        (i <= CAP_LAST ? ci->hw_bank.cap : ci->hw_bank.op) +
                        (is_lpm ? ci_regs_lpm[i] : ci_regs_nolpm[i]);

        for (; i <= OP_LAST; i++)
                ci->hw_bank.regmap[i] = ci->hw_bank.op +
                        4 * (i - OP_ENDPTCTRL) +
                        (is_lpm
                         ? ci_regs_lpm[OP_ENDPTCTRL]
                         : ci_regs_nolpm[OP_ENDPTCTRL]);

}

static enum ci_revision ci_get_revision(struct ci_hdrc *ci)
{
        int ver = hw_read_id_reg(ci, ID_ID, VERSION) >> __ffs(VERSION);
        enum ci_revision rev = CI_REVISION_UNKNOWN;

        if (ver == 0x2) {
                rev = hw_read_id_reg(ci, ID_ID, REVISION)
                        >> __ffs(REVISION);
                rev += CI_REVISION_20;
        } else if (ver == 0x0) {
                rev = CI_REVISION_1X;
        }

        return rev;
}

/**
 * hw_read_intr_enable: returns interrupt enable register
 *
 * @ci: the controller
 *
 * This function returns register data
 */
u32 hw_read_intr_enable(struct ci_hdrc *ci)
{
        return hw_read(ci, OP_USBINTR, ~0);
}

/**
 * hw_read_intr_status: returns interrupt status register
 *
 * @ci: the controller
 *
 * This function returns register data
 */
u32 hw_read_intr_status(struct ci_hdrc *ci)
{
        return hw_read(ci, OP_USBSTS, ~0);
}

/**
 * hw_port_test_set: writes port test mode (execute without interruption)
 * @mode: new value
 *
 * This function returns an error code
 */
int hw_port_test_set(struct ci_hdrc *ci, u8 mode)
{
        const u8 TEST_MODE_MAX = 7;

        if (mode > TEST_MODE_MAX)
                return -EINVAL;

        hw_write(ci, OP_PORTSC, PORTSC_PTC, mode << __ffs(PORTSC_PTC));
        return 0;
}

/**
 * hw_port_test_get: reads port test mode value
 *
 * @ci: the controller
 *
 * This function returns port test mode value
 */
u8 hw_port_test_get(struct ci_hdrc *ci)
{
        return hw_read(ci, OP_PORTSC, PORTSC_PTC) >> __ffs(PORTSC_PTC);
}

static void hw_wait_phy_stable(void)
{
        /*
         * The phy needs some delay to output the stable status from low
         * power mode. And for OTGSC, the status inputs are debounced
         * using a 1 ms time constant, so, delay 2ms for controller to get
         * the stable status, like vbus and id when the phy leaves low power.
         */
        usleep_range(2000, 2500);
}

/* The PHY enters/leaves low power mode */
static void ci_hdrc_enter_lpm(struct ci_hdrc *ci, bool enable)
{
        enum ci_hw_regs reg = ci->hw_bank.lpm ? OP_DEVLC : OP_PORTSC;
        bool lpm = !!(hw_read(ci, reg, PORTSC_PHCD(ci->hw_bank.lpm)));

        if (enable && !lpm)
                hw_write(ci, reg, PORTSC_PHCD(ci->hw_bank.lpm),
                                PORTSC_PHCD(ci->hw_bank.lpm));
        else if (!enable && lpm)
                hw_write(ci, reg, PORTSC_PHCD(ci->hw_bank.lpm),
                                0);
}

static int hw_device_init(struct ci_hdrc *ci, void __iomem *base)
{
        u32 reg;

        /* bank is a module variable */
        ci->hw_bank.abs = base;

        ci->hw_bank.cap = ci->hw_bank.abs;
        ci->hw_bank.cap += ci->platdata->capoffset;
        ci->hw_bank.op = ci->hw_bank.cap + (ioread32(ci->hw_bank.cap) & 0xff);

        hw_alloc_regmap(ci, false);
        reg = hw_read(ci, CAP_HCCPARAMS, HCCPARAMS_LEN) >>
                __ffs(HCCPARAMS_LEN);
        ci->hw_bank.lpm  = reg;
        if (reg)
                hw_alloc_regmap(ci, !!reg);
        ci->hw_bank.size = ci->hw_bank.op - ci->hw_bank.abs;
        ci->hw_bank.size += OP_LAST;
        ci->hw_bank.size /= sizeof(u32);

        reg = hw_read(ci, CAP_DCCPARAMS, DCCPARAMS_DEN) >>
                __ffs(DCCPARAMS_DEN);
        ci->hw_ep_max = reg * 2;   /* cache hw ENDPT_MAX */

        if (ci->hw_ep_max > ENDPT_MAX)
                return -ENODEV;

        ci_hdrc_enter_lpm(ci, false);

        /* Disable all interrupts bits */
        hw_write(ci, OP_USBINTR, 0xffffffff, 0);

        /* Clear all interrupts status bits*/
        hw_write(ci, OP_USBSTS, 0xffffffff, 0xffffffff);

        ci->rev = ci_get_revision(ci);

        dev_dbg(ci->dev,
                "ChipIdea HDRC found, revision: %d, lpm: %d; cap: %p op: %p\n",
                ci->rev, ci->hw_bank.lpm, ci->hw_bank.cap, ci->hw_bank.op);

        /* setup lock mode ? */

        /* ENDPTSETUPSTAT is '0' by default */

        /* HCSPARAMS.bf.ppc SHOULD BE zero for device */

        return 0;
}

void hw_phymode_configure(struct ci_hdrc *ci)
{
        u32 portsc, lpm, sts = 0;

        switch (ci->platdata->phy_mode) {
        case USBPHY_INTERFACE_MODE_UTMI:
                portsc = PORTSC_PTS(PTS_UTMI);
                lpm = DEVLC_PTS(PTS_UTMI);
                break;
        case USBPHY_INTERFACE_MODE_UTMIW:
                portsc = PORTSC_PTS(PTS_UTMI) | PORTSC_PTW;
                lpm = DEVLC_PTS(PTS_UTMI) | DEVLC_PTW;
                break;
        case USBPHY_INTERFACE_MODE_ULPI:
                portsc = PORTSC_PTS(PTS_ULPI);
                lpm = DEVLC_PTS(PTS_ULPI);
                break;
        case USBPHY_INTERFACE_MODE_SERIAL:
                portsc = PORTSC_PTS(PTS_SERIAL);
                lpm = DEVLC_PTS(PTS_SERIAL);
                sts = 1;
                break;
        case USBPHY_INTERFACE_MODE_HSIC:
                portsc = PORTSC_PTS(PTS_HSIC);
                lpm = DEVLC_PTS(PTS_HSIC);
                break;
        default:
                return;
        }

        if (ci->hw_bank.lpm) {
                hw_write(ci, OP_DEVLC, DEVLC_PTS(7) | DEVLC_PTW, lpm);
                if (sts)
                        hw_write(ci, OP_DEVLC, DEVLC_STS, DEVLC_STS);
        } else {
                hw_write(ci, OP_PORTSC, PORTSC_PTS(7) | PORTSC_PTW, portsc);
                if (sts)
                        hw_write(ci, OP_PORTSC, PORTSC_STS, PORTSC_STS);
        }
}
EXPORT_SYMBOL_GPL(hw_phymode_configure);

/**
 * _ci_usb_phy_init: initialize phy taking in account both phy and usb_phy
 * interfaces
 * @ci: the controller
 *
 * This function returns an error code if the phy failed to init
 */
static int _ci_usb_phy_init(struct ci_hdrc *ci)
{
        int ret;

        if (ci->phy) {
                ret = phy_init(ci->phy);
                if (ret)
                        return ret;

                ret = phy_power_on(ci->phy);
                if (ret) {
                        phy_exit(ci->phy);
                        return ret;
                }
        } else {
                ret = usb_phy_init(ci->usb_phy);
        }

        return ret;
}

/**
 * _ci_usb_phy_exit: deinitialize phy taking in account both phy and usb_phy
 * interfaces
 * @ci: the controller
 */
static void ci_usb_phy_exit(struct ci_hdrc *ci)
{
        if (ci->platdata->flags & CI_HDRC_OVERRIDE_PHY_CONTROL)
                return;

        if (ci->phy) {
                phy_power_off(ci->phy);
                phy_exit(ci->phy);
        } else {
                usb_phy_shutdown(ci->usb_phy);
        }
}

/**
 * ci_usb_phy_init: initialize phy according to different phy type
 * @ci: the controller
 *
 * This function returns an error code if usb_phy_init has failed
 */
static int ci_usb_phy_init(struct ci_hdrc *ci)
{
        int ret;

        if (ci->platdata->flags & CI_HDRC_OVERRIDE_PHY_CONTROL)
                return 0;

        switch (ci->platdata->phy_mode) {
        case USBPHY_INTERFACE_MODE_UTMI:
        case USBPHY_INTERFACE_MODE_UTMIW:
        case USBPHY_INTERFACE_MODE_HSIC:
                ret = _ci_usb_phy_init(ci);
                if (!ret)
                        hw_wait_phy_stable();
                else
                        return ret;
                hw_phymode_configure(ci);
                break;
        case USBPHY_INTERFACE_MODE_ULPI:
        case USBPHY_INTERFACE_MODE_SERIAL:
                hw_phymode_configure(ci);
                ret = _ci_usb_phy_init(ci);
                if (ret)
                        return ret;
                break;
        default:
                ret = _ci_usb_phy_init(ci);
                if (!ret)
                        hw_wait_phy_stable();
        }

        return ret;
}


/**
 * ci_platform_configure: do controller configure
 * @ci: the controller
 *
 */
void ci_platform_configure(struct ci_hdrc *ci)
{
        bool is_device_mode, is_host_mode;

        is_device_mode = hw_read(ci, OP_USBMODE, USBMODE_CM) == USBMODE_CM_DC;
        is_host_mode = hw_read(ci, OP_USBMODE, USBMODE_CM) == USBMODE_CM_HC;

        if (is_device_mode) {
                phy_set_mode(ci->phy, PHY_MODE_USB_DEVICE);

                if (ci->platdata->flags & CI_HDRC_DISABLE_DEVICE_STREAMING)
                        hw_write(ci, OP_USBMODE, USBMODE_CI_SDIS,
                                 USBMODE_CI_SDIS);
        }

        if (is_host_mode) {
                phy_set_mode(ci->phy, PHY_MODE_USB_HOST);

                if (ci->platdata->flags & CI_HDRC_DISABLE_HOST_STREAMING)
                        hw_write(ci, OP_USBMODE, USBMODE_CI_SDIS,
                                 USBMODE_CI_SDIS);
        }

        if (ci->platdata->flags & CI_HDRC_FORCE_FULLSPEED) {
                if (ci->hw_bank.lpm)
                        hw_write(ci, OP_DEVLC, DEVLC_PFSC, DEVLC_PFSC);
                else
                        hw_write(ci, OP_PORTSC, PORTSC_PFSC, PORTSC_PFSC);
        }

        if (ci->platdata->flags & CI_HDRC_SET_NON_ZERO_TTHA)
                hw_write(ci, OP_TTCTRL, TTCTRL_TTHA_MASK, TTCTRL_TTHA);

        hw_write(ci, OP_USBCMD, 0xff0000, ci->platdata->itc_setting << 16);

        if (ci->platdata->flags & CI_HDRC_OVERRIDE_AHB_BURST)
                hw_write_id_reg(ci, ID_SBUSCFG, AHBBRST_MASK,
                        ci->platdata->ahb_burst_config);

        /* override burst size, take effect only when ahb_burst_config is 0 */
        if (!hw_read_id_reg(ci, ID_SBUSCFG, AHBBRST_MASK)) {
                if (ci->platdata->flags & CI_HDRC_OVERRIDE_TX_BURST)
                        hw_write(ci, OP_BURSTSIZE, TX_BURST_MASK,
                        ci->platdata->tx_burst_size << __ffs(TX_BURST_MASK));

                if (ci->platdata->flags & CI_HDRC_OVERRIDE_RX_BURST)
                        hw_write(ci, OP_BURSTSIZE, RX_BURST_MASK,
                                ci->platdata->rx_burst_size);
        }
}

/**
 * hw_controller_reset: do controller reset
 * @ci: the controller
  *
 * This function returns an error code
 */
static int hw_controller_reset(struct ci_hdrc *ci)
{
        int count = 0;

        hw_write(ci, OP_USBCMD, USBCMD_RST, USBCMD_RST);
        while (hw_read(ci, OP_USBCMD, USBCMD_RST)) {
                udelay(10);
                if (count++ > 1000)
                        return -ETIMEDOUT;
        }

        return 0;
}

/**
 * hw_device_reset: resets chip (execute without interruption)
 * @ci: the controller
 *
 * This function returns an error code
 */
int hw_device_reset(struct ci_hdrc *ci)
{
        int ret;

        /* should flush & stop before reset */
        hw_write(ci, OP_ENDPTFLUSH, ~0, ~0);
        hw_write(ci, OP_USBCMD, USBCMD_RS, 0);

        ret = hw_controller_reset(ci);
        if (ret) {
                dev_err(ci->dev, "error resetting controller, ret=%d\n", ret);
                return ret;
        }

        if (ci->platdata->notify_event) {
                ret = ci->platdata->notify_event(ci,
                        CI_HDRC_CONTROLLER_RESET_EVENT);
                if (ret)
                        return ret;
        }

        /* USBMODE should be configured step by step */
        hw_write(ci, OP_USBMODE, USBMODE_CM, USBMODE_CM_IDLE);
        hw_write(ci, OP_USBMODE, USBMODE_CM, USBMODE_CM_DC);
        /* HW >= 2.3 */
        hw_write(ci, OP_USBMODE, USBMODE_SLOM, USBMODE_SLOM);

        if (hw_read(ci, OP_USBMODE, USBMODE_CM) != USBMODE_CM_DC) {
                pr_err("cannot enter in %s device mode", ci_role(ci)->name);
                pr_err("lpm = %i", ci->hw_bank.lpm);
                return -ENODEV;
        }

        ci_platform_configure(ci);

        return 0;
}

static irqreturn_t ci_irq(int irq, void *data)
{
        struct ci_hdrc *ci = data;
        irqreturn_t ret = IRQ_NONE;
        u32 otgsc = 0;

        if (ci->in_lpm) {
                disable_irq_nosync(irq);
                ci->wakeup_int = true;
                pm_runtime_get(ci->dev);
                return IRQ_HANDLED;
        }

        if (ci->is_otg) {
                otgsc = hw_read_otgsc(ci, ~0);
                if (ci_otg_is_fsm_mode(ci)) {
                        ret = ci_otg_fsm_irq(ci);
                        if (ret == IRQ_HANDLED)
                                return ret;
                }
        }

        /*
         * Handle id change interrupt, it indicates device/host function
         * switch.
         */
        if (ci->is_otg && (otgsc & OTGSC_IDIE) && (otgsc & OTGSC_IDIS)) {
                ci->id_event = true;
                /* Clear ID change irq status */
                hw_write_otgsc(ci, OTGSC_IDIS, OTGSC_IDIS);
                ci_otg_queue_work(ci);
                return IRQ_HANDLED;
        }

        /*
         * Handle vbus change interrupt, it indicates device connection
         * and disconnection events.
         */
        if (ci->is_otg && (otgsc & OTGSC_BSVIE) && (otgsc & OTGSC_BSVIS)) {
                ci->b_sess_valid_event = true;
                /* Clear BSV irq */
                hw_write_otgsc(ci, OTGSC_BSVIS, OTGSC_BSVIS);
                ci_otg_queue_work(ci);
                return IRQ_HANDLED;
        }

        /* Handle device/host interrupt */
        if (ci->role != CI_ROLE_END)
                ret = ci_role(ci)->irq(ci);

        return ret;
}

static int ci_cable_notifier(struct notifier_block *nb, unsigned long event,
                             void *ptr)
{
        struct ci_hdrc_cable *cbl = container_of(nb, struct ci_hdrc_cable, nb);
        struct ci_hdrc *ci = cbl->ci;

        cbl->connected = event;
        cbl->changed = true;

        ci_irq(ci->irq, ci);
        return NOTIFY_DONE;
}

static int ci_get_platdata(struct device *dev,
                struct ci_hdrc_platform_data *platdata)
{
        struct extcon_dev *ext_vbus, *ext_id;
        struct ci_hdrc_cable *cable;
        int ret;

        if (!platdata->phy_mode)
                platdata->phy_mode = of_usb_get_phy_mode(dev->of_node);

        if (!platdata->dr_mode)
                platdata->dr_mode = usb_get_dr_mode(dev);

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

        if (platdata->dr_mode != USB_DR_MODE_PERIPHERAL) {
                /* Get the vbus regulator */
                platdata->reg_vbus = devm_regulator_get(dev, "vbus");
                if (PTR_ERR(platdata->reg_vbus) == -EPROBE_DEFER) {
                        return -EPROBE_DEFER;
                } else if (PTR_ERR(platdata->reg_vbus) == -ENODEV) {
                        /* no vbus regulator is needed */
                        platdata->reg_vbus = NULL;
                } else if (IS_ERR(platdata->reg_vbus)) {
                        dev_err(dev, "Getting regulator error: %ld\n",
                                PTR_ERR(platdata->reg_vbus));
                        return PTR_ERR(platdata->reg_vbus);
                }
                /* Get TPL support */
                if (!platdata->tpl_support)
                        platdata->tpl_support =
                                of_usb_host_tpl_support(dev->of_node);
        }

        if (platdata->dr_mode == USB_DR_MODE_OTG) {
                /* We can support HNP and SRP of OTG 2.0 */
                platdata->ci_otg_caps.otg_rev = 0x0200;
                platdata->ci_otg_caps.hnp_support = true;
                platdata->ci_otg_caps.srp_support = true;

                /* Update otg capabilities by DT properties */
                ret = of_usb_update_otg_caps(dev->of_node,
                                        &platdata->ci_otg_caps);
                if (ret)
                        return ret;
        }

        if (usb_get_maximum_speed(dev) == USB_SPEED_FULL)
                platdata->flags |= CI_HDRC_FORCE_FULLSPEED;

        of_property_read_u32(dev->of_node, "phy-clkgate-delay-us",
                                     &platdata->phy_clkgate_delay_us);

        platdata->itc_setting = 1;

        of_property_read_u32(dev->of_node, "itc-setting",
                                        &platdata->itc_setting);

        ret = of_property_read_u32(dev->of_node, "ahb-burst-config",
                                &platdata->ahb_burst_config);
        if (!ret) {
                platdata->flags |= CI_HDRC_OVERRIDE_AHB_BURST;
        } else if (ret != -EINVAL) {
                dev_err(dev, "failed to get ahb-burst-config\n");
                return ret;
        }

        ret = of_property_read_u32(dev->of_node, "tx-burst-size-dword",
                                &platdata->tx_burst_size);
        if (!ret) {
                platdata->flags |= CI_HDRC_OVERRIDE_TX_BURST;
        } else if (ret != -EINVAL) {
                dev_err(dev, "failed to get tx-burst-size-dword\n");
                return ret;
        }

        ret = of_property_read_u32(dev->of_node, "rx-burst-size-dword",
                                &platdata->rx_burst_size);
        if (!ret) {
                platdata->flags |= CI_HDRC_OVERRIDE_RX_BURST;
        } else if (ret != -EINVAL) {
                dev_err(dev, "failed to get rx-burst-size-dword\n");
                return ret;
        }

        if (of_find_property(dev->of_node, "non-zero-ttctrl-ttha", NULL))
                platdata->flags |= CI_HDRC_SET_NON_ZERO_TTHA;

        ext_id = ERR_PTR(-ENODEV);
        ext_vbus = ERR_PTR(-ENODEV);
        if (of_property_read_bool(dev->of_node, "extcon")) {
                /* Each one of them is not mandatory */
                ext_vbus = extcon_get_edev_by_phandle(dev, 0);
                if (IS_ERR(ext_vbus) && PTR_ERR(ext_vbus) != -ENODEV)
                        return PTR_ERR(ext_vbus);

                ext_id = extcon_get_edev_by_phandle(dev, 1);
                if (IS_ERR(ext_id) && PTR_ERR(ext_id) != -ENODEV)
                        return PTR_ERR(ext_id);
        }

        cable = &platdata->vbus_extcon;
        cable->nb.notifier_call = ci_cable_notifier;
        cable->edev = ext_vbus;

        if (!IS_ERR(ext_vbus)) {
                ret = extcon_get_state(cable->edev, EXTCON_USB);
                if (ret)
                        cable->connected = true;
                else
                        cable->connected = false;
        }

        cable = &platdata->id_extcon;
        cable->nb.notifier_call = ci_cable_notifier;
        cable->edev = ext_id;

        if (!IS_ERR(ext_id)) {
                ret = extcon_get_state(cable->edev, EXTCON_USB_HOST);
                if (ret)
                        cable->connected = true;
                else
                        cable->connected = false;
        }
        return 0;
}

static int ci_extcon_register(struct ci_hdrc *ci)
{
        struct ci_hdrc_cable *id, *vbus;
        int ret;

        id = &ci->platdata->id_extcon;
        id->ci = ci;
        if (!IS_ERR_OR_NULL(id->edev)) {
                ret = devm_extcon_register_notifier(ci->dev, id->edev,
                                                EXTCON_USB_HOST, &id->nb);
                if (ret < 0) {
                        dev_err(ci->dev, "register ID failed\n");
                        return ret;
                }
        }

        vbus = &ci->platdata->vbus_extcon;
        vbus->ci = ci;
        if (!IS_ERR_OR_NULL(vbus->edev)) {
                ret = devm_extcon_register_notifier(ci->dev, vbus->edev,
                                                EXTCON_USB, &vbus->nb);
                if (ret < 0) {
                        dev_err(ci->dev, "register VBUS failed\n");
                        return ret;
                }
        }

        return 0;
}

static DEFINE_IDA(ci_ida);

struct platform_device *ci_hdrc_add_device(struct device *dev,
                        struct resource *res, int nres,
                        struct ci_hdrc_platform_data *platdata)
{
        struct platform_device *pdev;
        int id, ret;

        ret = ci_get_platdata(dev, platdata);
        if (ret)
                return ERR_PTR(ret);

        id = ida_simple_get(&ci_ida, 0, 0, GFP_KERNEL);
        if (id < 0)
                return ERR_PTR(id);

        pdev = platform_device_alloc("ci_hdrc", id);
        if (!pdev) {
                ret = -ENOMEM;
                goto put_id;
        }

        pdev->dev.parent = dev;

        ret = platform_device_add_resources(pdev, res, nres);
        if (ret)
                goto err;

        ret = platform_device_add_data(pdev, platdata, sizeof(*platdata));
        if (ret)
                goto err;

        ret = platform_device_add(pdev);
        if (ret)
                goto err;

        return pdev;

err:
        platform_device_put(pdev);
put_id:
        ida_simple_remove(&ci_ida, id);
        return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(ci_hdrc_add_device);

void ci_hdrc_remove_device(struct platform_device *pdev)
{
        int id = pdev->id;
        platform_device_unregister(pdev);
        ida_simple_remove(&ci_ida, id);
}
EXPORT_SYMBOL_GPL(ci_hdrc_remove_device);

static inline void ci_role_destroy(struct ci_hdrc *ci)
{
        ci_hdrc_gadget_destroy(ci);
        ci_hdrc_host_destroy(ci);
        if (ci->is_otg && ci->roles[CI_ROLE_GADGET])
                ci_hdrc_otg_destroy(ci);
}

static void ci_get_otg_capable(struct ci_hdrc *ci)
{
        if (ci->platdata->flags & CI_HDRC_DUAL_ROLE_NOT_OTG)
                ci->is_otg = false;
        else
                ci->is_otg = (hw_read(ci, CAP_DCCPARAMS,
                                DCCPARAMS_DC | DCCPARAMS_HC)
                                        == (DCCPARAMS_DC | DCCPARAMS_HC));
        if (ci->is_otg) {
                dev_dbg(ci->dev, "It is OTG capable controller\n");
                /* Disable and clear all OTG irq */
                hw_write_otgsc(ci, OTGSC_INT_EN_BITS | OTGSC_INT_STATUS_BITS,
                                                        OTGSC_INT_STATUS_BITS);
        }
}

static ssize_t ci_role_show(struct device *dev, struct device_attribute *attr,
                          char *buf)
{
        struct ci_hdrc *ci = dev_get_drvdata(dev);

        if (ci->role != CI_ROLE_END)
                return sprintf(buf, "%s\n", ci_role(ci)->name);

        return 0;
}

static ssize_t ci_role_store(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t n)
{
        struct ci_hdrc *ci = dev_get_drvdata(dev);
        enum ci_role role;
        int ret;

        if (!(ci->roles[CI_ROLE_HOST] && ci->roles[CI_ROLE_GADGET])) {
                dev_warn(dev, "Current configuration is not dual-role, quit\n");
                return -EPERM;
        }

        for (role = CI_ROLE_HOST; role < CI_ROLE_END; role++)
                if (!strncmp(buf, ci->roles[role]->name,
                             strlen(ci->roles[role]->name)))
                        break;

        if (role == CI_ROLE_END || role == ci->role)
                return -EINVAL;

        pm_runtime_get_sync(dev);
        disable_irq(ci->irq);
        ci_role_stop(ci);
        ret = ci_role_start(ci, role);
        if (!ret && ci->role == CI_ROLE_GADGET)
                ci_handle_vbus_change(ci);
        enable_irq(ci->irq);
        pm_runtime_put_sync(dev);

        return (ret == 0) ? n : ret;
}
static DEVICE_ATTR(role, 0644, ci_role_show, ci_role_store);

static struct attribute *ci_attrs[] = {
        &dev_attr_role.attr,
        NULL,
};

static const struct attribute_group ci_attr_group = {
        .attrs = ci_attrs,
};

static int ci_hdrc_probe(struct platform_device *pdev)
{
        struct device   *dev = &pdev->dev;
        struct ci_hdrc  *ci;
        struct resource *res;
        void __iomem    *base;
        int             ret;
        enum usb_dr_mode dr_mode;

        if (!dev_get_platdata(dev)) {
                dev_err(dev, "platform data missing\n");
                return -ENODEV;
        }

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        base = devm_ioremap_resource(dev, res);
        if (IS_ERR(base))
                return PTR_ERR(base);

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

        spin_lock_init(&ci->lock);
        ci->dev = dev;
        ci->platdata = dev_get_platdata(dev);
        ci->imx28_write_fix = !!(ci->platdata->flags &
                CI_HDRC_IMX28_WRITE_FIX);
        ci->supports_runtime_pm = !!(ci->platdata->flags &
                CI_HDRC_SUPPORTS_RUNTIME_PM);
        platform_set_drvdata(pdev, ci);

        ret = hw_device_init(ci, base);
        if (ret < 0) {
                dev_err(dev, "can't initialize hardware\n");
                return -ENODEV;
        }

        ret = ci_ulpi_init(ci);
        if (ret)
                return ret;

        if (ci->platdata->phy) {
                ci->phy = ci->platdata->phy;
        } else if (ci->platdata->usb_phy) {
                ci->usb_phy = ci->platdata->usb_phy;
        } else {
                ci->phy = devm_phy_get(dev->parent, "usb-phy");
                ci->usb_phy = devm_usb_get_phy(dev->parent, USB_PHY_TYPE_USB2);

                /* if both generic PHY and USB PHY layers aren't enabled */
                if (PTR_ERR(ci->phy) == -ENOSYS &&
                                PTR_ERR(ci->usb_phy) == -ENXIO) {
                        ret = -ENXIO;
                        goto ulpi_exit;
                }

                if (IS_ERR(ci->phy) && IS_ERR(ci->usb_phy)) {
                        ret = -EPROBE_DEFER;
                        goto ulpi_exit;
                }

                if (IS_ERR(ci->phy))
                        ci->phy = NULL;
                else if (IS_ERR(ci->usb_phy))
                        ci->usb_phy = NULL;
        }

        ret = ci_usb_phy_init(ci);
        if (ret) {
                dev_err(dev, "unable to init phy: %d\n", ret);
                return ret;
        }

        ci->hw_bank.phys = res->start;

        ci->irq = platform_get_irq(pdev, 0);
        if (ci->irq < 0) {
                dev_err(dev, "missing IRQ\n");
                ret = ci->irq;
                goto deinit_phy;
        }

        ci_get_otg_capable(ci);

        dr_mode = ci->platdata->dr_mode;
        /* initialize role(s) before the interrupt is requested */
        if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_HOST) {
                ret = ci_hdrc_host_init(ci);
                if (ret) {
                        if (ret == -ENXIO)
                                dev_info(dev, "doesn't support host\n");
                        else
                                goto deinit_phy;
                }
        }

        if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_PERIPHERAL) {
                ret = ci_hdrc_gadget_init(ci);
                if (ret) {
                        if (ret == -ENXIO)
                                dev_info(dev, "doesn't support gadget\n");
                        else
                                goto deinit_host;
                }
        }

        if (!ci->roles[CI_ROLE_HOST] && !ci->roles[CI_ROLE_GADGET]) {
                dev_err(dev, "no supported roles\n");
                ret = -ENODEV;

                goto deinit_gadget;
        }

        if (ci->is_otg && ci->roles[CI_ROLE_GADGET]) {
                ret = ci_hdrc_otg_init(ci);
                if (ret) {
                        dev_err(dev, "init otg fails, ret = %d\n", ret);
                        goto deinit_gadget;
                }
        }

        if (ci->roles[CI_ROLE_HOST] && ci->roles[CI_ROLE_GADGET]) {
                if (ci->is_otg) {
                        ci->role = ci_otg_role(ci);
                        /* Enable ID change irq */
                        hw_write_otgsc(ci, OTGSC_IDIE, OTGSC_IDIE);
                } else {
                        /*
                         * If the controller is not OTG capable, but support
                         * role switch, the defalt role is gadget, and the
                         * user can switch it through debugfs.
                         */
                        ci->role = CI_ROLE_GADGET;
                }
        } else {
                ci->role = ci->roles[CI_ROLE_HOST]
                        ? CI_ROLE_HOST
                        : CI_ROLE_GADGET;
        }

        if (!ci_otg_is_fsm_mode(ci)) {
                /* only update vbus status for peripheral */
                if (ci->role == CI_ROLE_GADGET)
                        ci_handle_vbus_change(ci);

                ret = ci_role_start(ci, ci->role);
                if (ret) {
                        dev_err(dev, "can't start %s role\n",
                                                ci_role(ci)->name);
                        goto stop;
                }
        }

        ret = devm_request_irq(dev, ci->irq, ci_irq, IRQF_SHARED,
                        ci->platdata->name, ci);
        if (ret)
                goto stop;

        ret = ci_extcon_register(ci);
        if (ret)
                goto stop;

        if (ci->supports_runtime_pm) {
                pm_runtime_set_active(&pdev->dev);
                pm_runtime_enable(&pdev->dev);
                pm_runtime_set_autosuspend_delay(&pdev->dev, 2000);
                pm_runtime_mark_last_busy(ci->dev);
                pm_runtime_use_autosuspend(&pdev->dev);
        }

        if (ci_otg_is_fsm_mode(ci))
                ci_hdrc_otg_fsm_start(ci);

        device_set_wakeup_capable(&pdev->dev, true);
        ret = dbg_create_files(ci);
        if (ret)
                goto stop;

        ret = sysfs_create_group(&dev->kobj, &ci_attr_group);
        if (ret)
                goto remove_debug;

        return 0;

remove_debug:
        dbg_remove_files(ci);
stop:
        if (ci->is_otg && ci->roles[CI_ROLE_GADGET])
                ci_hdrc_otg_destroy(ci);
deinit_gadget:
        ci_hdrc_gadget_destroy(ci);
deinit_host:
        ci_hdrc_host_destroy(ci);
deinit_phy:
        ci_usb_phy_exit(ci);
ulpi_exit:
        ci_ulpi_exit(ci);

        return ret;
}

static int ci_hdrc_remove(struct platform_device *pdev)
{
        struct ci_hdrc *ci = platform_get_drvdata(pdev);

        if (ci->supports_runtime_pm) {
                pm_runtime_get_sync(&pdev->dev);
                pm_runtime_disable(&pdev->dev);
                pm_runtime_put_noidle(&pdev->dev);
        }

        dbg_remove_files(ci);
        sysfs_remove_group(&ci->dev->kobj, &ci_attr_group);
        ci_role_destroy(ci);
        ci_hdrc_enter_lpm(ci, true);
        ci_usb_phy_exit(ci);
        ci_ulpi_exit(ci);

        return 0;
}

#ifdef CONFIG_PM
/* Prepare wakeup by SRP before suspend */
static void ci_otg_fsm_suspend_for_srp(struct ci_hdrc *ci)
{
        if ((ci->fsm.otg->state == OTG_STATE_A_IDLE) &&
                                !hw_read_otgsc(ci, OTGSC_ID)) {
                hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS | PORTSC_PP,
                                                                PORTSC_PP);
                hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS | PORTSC_WKCN,
                                                                PORTSC_WKCN);
        }
}

/* Handle SRP when wakeup by data pulse */
static void ci_otg_fsm_wakeup_by_srp(struct ci_hdrc *ci)
{
        if ((ci->fsm.otg->state == OTG_STATE_A_IDLE) &&
                (ci->fsm.a_bus_drop == 1) && (ci->fsm.a_bus_req == 0)) {
                if (!hw_read_otgsc(ci, OTGSC_ID)) {
                        ci->fsm.a_srp_det = 1;
                        ci->fsm.a_bus_drop = 0;
                } else {
                        ci->fsm.id = 1;
                }
                ci_otg_queue_work(ci);
        }
}

static void ci_controller_suspend(struct ci_hdrc *ci)
{
        disable_irq(ci->irq);
        ci_hdrc_enter_lpm(ci, true);
        if (ci->platdata->phy_clkgate_delay_us)
                usleep_range(ci->platdata->phy_clkgate_delay_us,
                             ci->platdata->phy_clkgate_delay_us + 50);
        usb_phy_set_suspend(ci->usb_phy, 1);
        ci->in_lpm = true;
        enable_irq(ci->irq);
}

static int ci_controller_resume(struct device *dev)
{
        struct ci_hdrc *ci = dev_get_drvdata(dev);
        int ret;

        dev_dbg(dev, "at %s\n", __func__);

        if (!ci->in_lpm) {
                WARN_ON(1);
                return 0;
        }

        ci_hdrc_enter_lpm(ci, false);

        ret = ci_ulpi_resume(ci);
        if (ret)
                return ret;

        if (ci->usb_phy) {
                usb_phy_set_suspend(ci->usb_phy, 0);
                usb_phy_set_wakeup(ci->usb_phy, false);
                hw_wait_phy_stable();
        }

        ci->in_lpm = false;
        if (ci->wakeup_int) {
                ci->wakeup_int = false;
                pm_runtime_mark_last_busy(ci->dev);
                pm_runtime_put_autosuspend(ci->dev);
                enable_irq(ci->irq);
                if (ci_otg_is_fsm_mode(ci))
                        ci_otg_fsm_wakeup_by_srp(ci);
        }

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int ci_suspend(struct device *dev)
{
        struct ci_hdrc *ci = dev_get_drvdata(dev);

        if (ci->wq)
                flush_workqueue(ci->wq);
        /*
         * Controller needs to be active during suspend, otherwise the core
         * may run resume when the parent is at suspend if other driver's
         * suspend fails, it occurs before parent's suspend has not started,
         * but the core suspend has finished.
         */
        if (ci->in_lpm)
                pm_runtime_resume(dev);

        if (ci->in_lpm) {
                WARN_ON(1);
                return 0;
        }

        if (device_may_wakeup(dev)) {
                if (ci_otg_is_fsm_mode(ci))
                        ci_otg_fsm_suspend_for_srp(ci);

                usb_phy_set_wakeup(ci->usb_phy, true);
                enable_irq_wake(ci->irq);
        }

        ci_controller_suspend(ci);

        return 0;
}

static int ci_resume(struct device *dev)
{
        struct ci_hdrc *ci = dev_get_drvdata(dev);
        int ret;

        if (device_may_wakeup(dev))
                disable_irq_wake(ci->irq);

        ret = ci_controller_resume(dev);
        if (ret)
                return ret;

        if (ci->supports_runtime_pm) {
                pm_runtime_disable(dev);
                pm_runtime_set_active(dev);
                pm_runtime_enable(dev);
        }

        return ret;
}
#endif /* CONFIG_PM_SLEEP */

static int ci_runtime_suspend(struct device *dev)
{
        struct ci_hdrc *ci = dev_get_drvdata(dev);

        dev_dbg(dev, "at %s\n", __func__);

        if (ci->in_lpm) {
                WARN_ON(1);
                return 0;
        }

        if (ci_otg_is_fsm_mode(ci))
                ci_otg_fsm_suspend_for_srp(ci);

        usb_phy_set_wakeup(ci->usb_phy, true);
        ci_controller_suspend(ci);

        return 0;
}

static int ci_runtime_resume(struct device *dev)
{
        return ci_controller_resume(dev);
}

#endif /* CONFIG_PM */
static const struct dev_pm_ops ci_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(ci_suspend, ci_resume)
        SET_RUNTIME_PM_OPS(ci_runtime_suspend, ci_runtime_resume, NULL)
};

static struct platform_driver ci_hdrc_driver = {
        .probe  = ci_hdrc_probe,
        .remove = ci_hdrc_remove,
        .driver = {
                .name   = "ci_hdrc",
                .pm     = &ci_pm_ops,
        },
};

static int __init ci_hdrc_platform_register(void)
{
        ci_hdrc_host_driver_init();
        return platform_driver_register(&ci_hdrc_driver);
}
module_init(ci_hdrc_platform_register);

static void __exit ci_hdrc_platform_unregister(void)
{
        platform_driver_unregister(&ci_hdrc_driver);
}
module_exit(ci_hdrc_platform_unregister);

MODULE_ALIAS("platform:ci_hdrc");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("David Lopo <dlopo@chipidea.mips.com>");
MODULE_DESCRIPTION("ChipIdea HDRC Driver");