// SPDX-License-Identifier: GPL-2.0+
/*
 * drivers/usb/gadget/dwc2_udc_otg.c
 * Designware DWC2 on-chip full/high speed USB OTG 2.0 device controllers
 *
 * Copyright (C) 2008 for Samsung Electronics
 *
 * BSP Support for Samsung's UDC driver
 * available at:
 * git://git.kernel.org/pub/scm/linux/kernel/git/kki_ap/linux-2.6-samsung.git
 *
 * State machine bugfixes:
 * Marek Szyprowski <m.szyprowski@samsung.com>
 *
 * Ported to u-boot:
 * Marek Szyprowski <m.szyprowski@samsung.com>
 * Lukasz Majewski <l.majewski@samsumg.com>
 */
#undef DEBUG
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <generic-phy.h>
#include <log.h>
#include <malloc.h>
#include <reset.h>
#include <dm/device_compat.h>
#include <dm/devres.h>
#include <linux/bug.h>
#include <linux/delay.h>

#include <linux/errno.h>
#include <linux/list.h>

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

#include <phys2bus.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include <asm/io.h>

#include <asm/mach-types.h>

#include <power/regulator.h>

#include "dwc2_udc_otg_regs.h"
#include "dwc2_udc_otg_priv.h"

/***********************************************************/

#define OTG_DMA_MODE            1

#define DEBUG_SETUP 0
#define DEBUG_EP0 0
#define DEBUG_ISR 0
#define DEBUG_OUT_EP 0
#define DEBUG_IN_EP 0

#include <usb/dwc2_udc.h>

#define EP0_CON         0
#define EP_MASK         0xF

static char *state_names[] = {
        "WAIT_FOR_SETUP",
        "DATA_STATE_XMIT",
        "DATA_STATE_NEED_ZLP",
        "WAIT_FOR_OUT_STATUS",
        "DATA_STATE_RECV",
        "WAIT_FOR_COMPLETE",
        "WAIT_FOR_OUT_COMPLETE",
        "WAIT_FOR_IN_COMPLETE",
        "WAIT_FOR_NULL_COMPLETE",
};

#define DRIVER_VERSION "15 March 2009"

struct dwc2_udc *the_controller;

static const char driver_name[] = "dwc2-udc";
static const char ep0name[] = "ep0-control";

/* Max packet size*/
static unsigned int ep0_fifo_size = 64;
static unsigned int ep_fifo_size =  512;
static unsigned int ep_fifo_size2 = 1024;
static int reset_available = 1;

static struct usb_ctrlrequest *usb_ctrl;
static dma_addr_t usb_ctrl_dma_addr;

/*
  Local declarations.
*/
static int dwc2_ep_enable(struct usb_ep *ep,
                         const struct usb_endpoint_descriptor *);
static int dwc2_ep_disable(struct usb_ep *ep);
static struct usb_request *dwc2_alloc_request(struct usb_ep *ep,
                                             gfp_t gfp_flags);
static void dwc2_free_request(struct usb_ep *ep, struct usb_request *);

static int dwc2_queue(struct usb_ep *ep, struct usb_request *, gfp_t gfp_flags);
static int dwc2_dequeue(struct usb_ep *ep, struct usb_request *);
static int dwc2_fifo_status(struct usb_ep *ep);
static void dwc2_fifo_flush(struct usb_ep *ep);
static void dwc2_ep0_read(struct dwc2_udc *dev);
static void dwc2_ep0_kick(struct dwc2_udc *dev, struct dwc2_ep *ep);
static void dwc2_handle_ep0(struct dwc2_udc *dev);
static int dwc2_ep0_write(struct dwc2_udc *dev);
static int write_fifo_ep0(struct dwc2_ep *ep, struct dwc2_request *req);
static void done(struct dwc2_ep *ep, struct dwc2_request *req, int status);
static void stop_activity(struct dwc2_udc *dev,
                          struct usb_gadget_driver *driver);
static int udc_enable(struct dwc2_udc *dev);
static void udc_set_address(struct dwc2_udc *dev, unsigned char address);
static void reconfig_usbd(struct dwc2_udc *dev);
static void set_max_pktsize(struct dwc2_udc *dev, enum usb_device_speed speed);
static void nuke(struct dwc2_ep *ep, int status);
static int dwc2_udc_set_halt(struct usb_ep *_ep, int value);
static void dwc2_udc_set_nak(struct dwc2_ep *ep);

void set_udc_gadget_private_data(void *p)
{
        debug_cond(DEBUG_SETUP != 0,
                   "%s: the_controller: 0x%p, p: 0x%p\n", __func__,
                   the_controller, p);
        the_controller->gadget.dev.device_data = p;
}

void *get_udc_gadget_private_data(struct usb_gadget *gadget)
{
        return gadget->dev.device_data;
}

static struct usb_ep_ops dwc2_ep_ops = {
        .enable = dwc2_ep_enable,
        .disable = dwc2_ep_disable,

        .alloc_request = dwc2_alloc_request,
        .free_request = dwc2_free_request,

        .queue = dwc2_queue,
        .dequeue = dwc2_dequeue,

        .set_halt = dwc2_udc_set_halt,
        .fifo_status = dwc2_fifo_status,
        .fifo_flush = dwc2_fifo_flush,
};

#define create_proc_files() do {} while (0)
#define remove_proc_files() do {} while (0)

/***********************************************************/

struct dwc2_usbotg_reg *reg;

bool dfu_usb_get_reset(void)
{
        return !!(readl(&reg->gintsts) & INT_RESET);
}

__weak void otg_phy_init(struct dwc2_udc *dev) {}
__weak void otg_phy_off(struct dwc2_udc *dev) {}

/***********************************************************/

#include "dwc2_udc_otg_xfer_dma.c"

/*
 *      udc_disable - disable USB device controller
 */
static void udc_disable(struct dwc2_udc *dev)
{
        debug_cond(DEBUG_SETUP != 0, "%s: %p\n", __func__, dev);

        udc_set_address(dev, 0);

        dev->ep0state = WAIT_FOR_SETUP;
        dev->gadget.speed = USB_SPEED_UNKNOWN;
        dev->usb_address = 0;

        otg_phy_off(dev);
}

/*
 *      udc_reinit - initialize software state
 */
static void udc_reinit(struct dwc2_udc *dev)
{
        unsigned int i;

        debug_cond(DEBUG_SETUP != 0, "%s: %p\n", __func__, dev);

        /* device/ep0 records init */
        INIT_LIST_HEAD(&dev->gadget.ep_list);
        INIT_LIST_HEAD(&dev->gadget.ep0->ep_list);
        dev->ep0state = WAIT_FOR_SETUP;

        /* basic endpoint records init */
        for (i = 0; i < DWC2_MAX_ENDPOINTS; i++) {
                struct dwc2_ep *ep = &dev->ep[i];

                if (i != 0)
                        list_add_tail(&ep->ep.ep_list, &dev->gadget.ep_list);

                ep->desc = 0;
                ep->stopped = 0;
                INIT_LIST_HEAD(&ep->queue);
                ep->pio_irqs = 0;
        }

        /* the rest was statically initialized, and is read-only */
}

#define BYTES2MAXP(x)   (x / 8)
#define MAXP2BYTES(x)   (x * 8)

/* until it's enabled, this UDC should be completely invisible
 * to any USB host.
 */
static int udc_enable(struct dwc2_udc *dev)
{
        debug_cond(DEBUG_SETUP != 0, "%s: %p\n", __func__, dev);

        otg_phy_init(dev);
        reconfig_usbd(dev);

        debug_cond(DEBUG_SETUP != 0,
                   "DWC2 USB 2.0 OTG Controller Core Initialized : 0x%x\n",
                    readl(&reg->gintmsk));

        dev->gadget.speed = USB_SPEED_UNKNOWN;

        return 0;
}

#if !CONFIG_IS_ENABLED(DM_USB_GADGET)
/*
  Register entry point for the peripheral controller driver.
*/
int usb_gadget_register_driver(struct usb_gadget_driver *driver)
{
        struct dwc2_udc *dev = the_controller;
        int retval = 0;
        unsigned long flags = 0;

        debug_cond(DEBUG_SETUP != 0, "%s: %s\n", __func__, "no name");

        if (!driver || driver->speed < USB_SPEED_FULL
            || !driver->bind || !driver->disconnect || !driver->setup)
                return -EINVAL;
        if (!dev)
                return -ENODEV;
        if (dev->driver)
                return -EBUSY;

        spin_lock_irqsave(&dev->lock, flags);
        /* first hook up the driver ... */
        dev->driver = driver;
        spin_unlock_irqrestore(&dev->lock, flags);

        if (retval) { /* TODO */
                printf("target device_add failed, error %d\n", retval);
                return retval;
        }

        retval = driver->bind(&dev->gadget);
        if (retval) {
                debug_cond(DEBUG_SETUP != 0,
                           "%s: bind to driver --> error %d\n",
                            dev->gadget.name, retval);
                dev->driver = 0;
                return retval;
        }

        enable_irq(IRQ_OTG);

        debug_cond(DEBUG_SETUP != 0,
                   "Registered gadget driver %s\n", dev->gadget.name);
        udc_enable(dev);

        return 0;
}

/*
 * Unregister entry point for the peripheral controller driver.
 */
int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
{
        struct dwc2_udc *dev = the_controller;
        unsigned long flags = 0;

        if (!dev)
                return -ENODEV;
        if (!driver || driver != dev->driver)
                return -EINVAL;

        spin_lock_irqsave(&dev->lock, flags);
        dev->driver = 0;
        stop_activity(dev, driver);
        spin_unlock_irqrestore(&dev->lock, flags);

        driver->unbind(&dev->gadget);

        disable_irq(IRQ_OTG);

        udc_disable(dev);
        return 0;
}
#else /* !CONFIG_IS_ENABLED(DM_USB_GADGET) */

static int dwc2_gadget_start(struct usb_gadget *g,
                             struct usb_gadget_driver *driver)
{
        struct dwc2_udc *dev = the_controller;

        debug_cond(DEBUG_SETUP != 0, "%s: %s\n", __func__, "no name");

        if (!driver || driver->speed < USB_SPEED_FULL ||
            !driver->bind || !driver->disconnect || !driver->setup)
                return -EINVAL;

        if (!dev)
                return -ENODEV;

        if (dev->driver)
                return -EBUSY;

        /* first hook up the driver ... */
        dev->driver = driver;

        debug_cond(DEBUG_SETUP != 0,
                   "Registered gadget driver %s\n", dev->gadget.name);
        return udc_enable(dev);
}

static int dwc2_gadget_stop(struct usb_gadget *g)
{
        struct dwc2_udc *dev = the_controller;

        if (!dev)
                return -ENODEV;

        if (!dev->driver)
                return -EINVAL;

        dev->driver = 0;
        stop_activity(dev, dev->driver);

        udc_disable(dev);

        return 0;
}

#endif /* !CONFIG_IS_ENABLED(DM_USB_GADGET) */

/*
 *      done - retire a request; caller blocked irqs
 */
static void done(struct dwc2_ep *ep, struct dwc2_request *req, int status)
{
        unsigned int stopped = ep->stopped;

        debug("%s: %s %p, req = %p, stopped = %d\n",
              __func__, ep->ep.name, ep, &req->req, stopped);

        list_del_init(&req->queue);

        if (likely(req->req.status == -EINPROGRESS))
                req->req.status = status;
        else
                status = req->req.status;

        if (status && status != -ESHUTDOWN) {
                debug("complete %s req %p stat %d len %u/%u\n",
                      ep->ep.name, &req->req, status,
                      req->req.actual, req->req.length);
        }

        /* don't modify queue heads during completion callback */
        ep->stopped = 1;

#ifdef DEBUG
        printf("calling complete callback\n");
        {
                int i, len = req->req.length;

                printf("pkt[%d] = ", req->req.length);
                if (len > 64)
                        len = 64;
                for (i = 0; i < len; i++) {
                        printf("%02x", ((u8 *)req->req.buf)[i]);
                        if ((i & 7) == 7)
                                printf(" ");
                }
                printf("\n");
        }
#endif
        spin_unlock(&ep->dev->lock);
        req->req.complete(&ep->ep, &req->req);
        spin_lock(&ep->dev->lock);

        debug("callback completed\n");

        ep->stopped = stopped;
}

/*
 *      nuke - dequeue ALL requests
 */
static void nuke(struct dwc2_ep *ep, int status)
{
        struct dwc2_request *req;

        debug("%s: %s %p\n", __func__, ep->ep.name, ep);

        /* called with irqs blocked */
        while (!list_empty(&ep->queue)) {
                req = list_entry(ep->queue.next, struct dwc2_request, queue);
                done(ep, req, status);
        }
}

static void stop_activity(struct dwc2_udc *dev,
                          struct usb_gadget_driver *driver)
{
        int i;

        /* don't disconnect drivers more than once */
        if (dev->gadget.speed == USB_SPEED_UNKNOWN)
                driver = 0;
        dev->gadget.speed = USB_SPEED_UNKNOWN;

        /* prevent new request submissions, kill any outstanding requests  */
        for (i = 0; i < DWC2_MAX_ENDPOINTS; i++) {
                struct dwc2_ep *ep = &dev->ep[i];
                ep->stopped = 1;
                nuke(ep, -ESHUTDOWN);
        }

        /* report disconnect; the driver is already quiesced */
        if (driver) {
                spin_unlock(&dev->lock);
                driver->disconnect(&dev->gadget);
                spin_lock(&dev->lock);
        }

        /* re-init driver-visible data structures */
        udc_reinit(dev);
}

static void reconfig_usbd(struct dwc2_udc *dev)
{
        /* 2. Soft-reset OTG Core and then unreset again. */
        int i;
        unsigned int uTemp = writel(CORE_SOFT_RESET, &reg->grstctl);
        uint32_t dflt_gusbcfg;
        uint32_t rx_fifo_sz, tx_fifo_sz, np_tx_fifo_sz;
        u32 max_hw_ep;
        int pdata_hw_ep;

        debug("Reseting OTG controller\n");

        dflt_gusbcfg =
                0<<15           /* PHY Low Power Clock sel*/
                |1<<14          /* Non-Periodic TxFIFO Rewind Enable*/
                |0x5<<10        /* Turnaround time*/
                |0<<9 | 0<<8    /* [0:HNP disable,1:HNP enable][ 0:SRP disable*/
                                /* 1:SRP enable] H1= 1,1*/
                |0<<7           /* Ulpi DDR sel*/
                |0<<6           /* 0: high speed utmi+, 1: full speed serial*/
                |0<<4           /* 0: utmi+, 1:ulpi*/
#ifdef CONFIG_USB_GADGET_DWC2_OTG_PHY_BUS_WIDTH_8
                |0<<3           /* phy i/f  0:8bit, 1:16bit*/
#else
                |1<<3           /* phy i/f  0:8bit, 1:16bit*/
#endif
                |0x7<<0;        /* HS/FS Timeout**/

        if (dev->pdata->usb_gusbcfg)
                dflt_gusbcfg = dev->pdata->usb_gusbcfg;

        writel(dflt_gusbcfg, &reg->gusbcfg);

        /* 3. Put the OTG device core in the disconnected state.*/
        uTemp = readl(&reg->dctl);
        uTemp |= SOFT_DISCONNECT;
        writel(uTemp, &reg->dctl);

        udelay(20);

        /* 4. Make the OTG device core exit from the disconnected state.*/
        uTemp = readl(&reg->dctl);
        uTemp = uTemp & ~SOFT_DISCONNECT;
        writel(uTemp, &reg->dctl);

        /* 5. Configure OTG Core to initial settings of device mode.*/
        /* [][1: full speed(30Mhz) 0:high speed]*/
        writel(EP_MISS_CNT(1) | DEV_SPEED_HIGH_SPEED_20, &reg->dcfg);

        mdelay(1);

        /* 6. Unmask the core interrupts*/
        writel(GINTMSK_INIT, &reg->gintmsk);

        /* 7. Set NAK bit of EP0, EP1, EP2*/
        writel(DEPCTL_EPDIS|DEPCTL_SNAK, &reg->out_endp[EP0_CON].doepctl);
        writel(DEPCTL_EPDIS|DEPCTL_SNAK, &reg->in_endp[EP0_CON].diepctl);

        for (i = 1; i < DWC2_MAX_ENDPOINTS; i++) {
                writel(DEPCTL_EPDIS|DEPCTL_SNAK, &reg->out_endp[i].doepctl);
                writel(DEPCTL_EPDIS|DEPCTL_SNAK, &reg->in_endp[i].diepctl);
        }

        /* 8. Unmask EPO interrupts*/
        writel(((1 << EP0_CON) << DAINT_OUT_BIT)
               | (1 << EP0_CON), &reg->daintmsk);

        /* 9. Unmask device OUT EP common interrupts*/
        writel(DOEPMSK_INIT, &reg->doepmsk);

        /* 10. Unmask device IN EP common interrupts*/
        writel(DIEPMSK_INIT, &reg->diepmsk);

        rx_fifo_sz = RX_FIFO_SIZE;
        np_tx_fifo_sz = NPTX_FIFO_SIZE;
        tx_fifo_sz = PTX_FIFO_SIZE;

        if (dev->pdata->rx_fifo_sz)
                rx_fifo_sz = dev->pdata->rx_fifo_sz;
        if (dev->pdata->np_tx_fifo_sz)
                np_tx_fifo_sz = dev->pdata->np_tx_fifo_sz;
        if (dev->pdata->tx_fifo_sz)
                tx_fifo_sz = dev->pdata->tx_fifo_sz;

        /* 11. Set Rx FIFO Size (in 32-bit words) */
        writel(rx_fifo_sz, &reg->grxfsiz);

        /* 12. Set Non Periodic Tx FIFO Size */
        writel((np_tx_fifo_sz << 16) | rx_fifo_sz,
               &reg->gnptxfsiz);

        /* retrieve the number of IN Endpoints (excluding ep0) */
        max_hw_ep = (readl(&reg->ghwcfg4) & GHWCFG4_NUM_IN_EPS_MASK) >>
                    GHWCFG4_NUM_IN_EPS_SHIFT;
        pdata_hw_ep = dev->pdata->tx_fifo_sz_nb;

        /* tx_fifo_sz_nb should equal to number of IN Endpoint */
        if (pdata_hw_ep && max_hw_ep != pdata_hw_ep)
                pr_warn("Got %d hw endpoint but %d tx-fifo-size in array !!\n",
                        max_hw_ep, pdata_hw_ep);

        for (i = 0; i < max_hw_ep; i++) {
                if (pdata_hw_ep)
                        tx_fifo_sz = dev->pdata->tx_fifo_sz_array[i];

                writel((rx_fifo_sz + np_tx_fifo_sz + (tx_fifo_sz * i)) |
                        tx_fifo_sz << 16, &reg->dieptxf[i]);
        }
        /* Flush the RX FIFO */
        writel(RX_FIFO_FLUSH, &reg->grstctl);
        while (readl(&reg->grstctl) & RX_FIFO_FLUSH)
                debug("%s: waiting for DWC2_UDC_OTG_GRSTCTL\n", __func__);

        /* Flush all the Tx FIFO's */
        writel(TX_FIFO_FLUSH_ALL, &reg->grstctl);
        writel(TX_FIFO_FLUSH_ALL | TX_FIFO_FLUSH, &reg->grstctl);
        while (readl(&reg->grstctl) & TX_FIFO_FLUSH)
                debug("%s: waiting for DWC2_UDC_OTG_GRSTCTL\n", __func__);

        /* 13. Clear NAK bit of EP0, EP1, EP2*/
        /* For Slave mode*/
        /* EP0: Control OUT */
        writel(DEPCTL_EPDIS | DEPCTL_CNAK,
               &reg->out_endp[EP0_CON].doepctl);

        /* 14. Initialize OTG Link Core.*/
        writel(GAHBCFG_INIT, &reg->gahbcfg);
}

static void set_max_pktsize(struct dwc2_udc *dev, enum usb_device_speed speed)
{
        unsigned int ep_ctrl;
        int i;

        if (speed == USB_SPEED_HIGH) {
                ep0_fifo_size = 64;
                ep_fifo_size = 512;
                ep_fifo_size2 = 1024;
                dev->gadget.speed = USB_SPEED_HIGH;
        } else {
                ep0_fifo_size = 64;
                ep_fifo_size = 64;
                ep_fifo_size2 = 64;
                dev->gadget.speed = USB_SPEED_FULL;
        }

        dev->ep[0].ep.maxpacket = ep0_fifo_size;
        for (i = 1; i < DWC2_MAX_ENDPOINTS; i++)
                dev->ep[i].ep.maxpacket = ep_fifo_size;

        /* EP0 - Control IN (64 bytes)*/
        ep_ctrl = readl(&reg->in_endp[EP0_CON].diepctl);
        writel(ep_ctrl|(0<<0), &reg->in_endp[EP0_CON].diepctl);

        /* EP0 - Control OUT (64 bytes)*/
        ep_ctrl = readl(&reg->out_endp[EP0_CON].doepctl);
        writel(ep_ctrl|(0<<0), &reg->out_endp[EP0_CON].doepctl);
}

static int dwc2_ep_enable(struct usb_ep *_ep,
                         const struct usb_endpoint_descriptor *desc)
{
        struct dwc2_ep *ep;
        struct dwc2_udc *dev;
        unsigned long flags = 0;

        debug("%s: %p\n", __func__, _ep);

        ep = container_of(_ep, struct dwc2_ep, ep);
        if (!_ep || !desc || ep->desc || _ep->name == ep0name
            || desc->bDescriptorType != USB_DT_ENDPOINT
            || ep->bEndpointAddress != desc->bEndpointAddress
            || ep_maxpacket(ep) <
            le16_to_cpu(get_unaligned(&desc->wMaxPacketSize))) {

                debug("%s: bad ep or descriptor\n", __func__);
                return -EINVAL;
        }

        /* xfer types must match, except that interrupt ~= bulk */
        if (ep->bmAttributes != desc->bmAttributes
            && ep->bmAttributes != USB_ENDPOINT_XFER_BULK
            && desc->bmAttributes != USB_ENDPOINT_XFER_INT) {

                debug("%s: %s type mismatch\n", __func__, _ep->name);
                return -EINVAL;
        }

        /* hardware _could_ do smaller, but driver doesn't */
        if ((desc->bmAttributes == USB_ENDPOINT_XFER_BULK &&
             le16_to_cpu(get_unaligned(&desc->wMaxPacketSize)) >
             ep_maxpacket(ep)) || !get_unaligned(&desc->wMaxPacketSize)) {

                debug("%s: bad %s maxpacket\n", __func__, _ep->name);
                return -ERANGE;
        }

        dev = ep->dev;
        if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN) {

                debug("%s: bogus device state\n", __func__);
                return -ESHUTDOWN;
        }

        _ep->desc = desc;
        ep->stopped = 0;
        ep->desc = desc;
        ep->pio_irqs = 0;
        ep->ep.maxpacket = le16_to_cpu(get_unaligned(&desc->wMaxPacketSize));

        /* Reset halt state */
        dwc2_udc_set_nak(ep);
        dwc2_udc_set_halt(_ep, 0);

        spin_lock_irqsave(&ep->dev->lock, flags);
        dwc2_udc_ep_activate(ep);
        spin_unlock_irqrestore(&ep->dev->lock, flags);

        debug("%s: enabled %s, stopped = %d, maxpacket = %d\n",
              __func__, _ep->name, ep->stopped, ep->ep.maxpacket);
        return 0;
}

/*
 * Disable EP
 */
static int dwc2_ep_disable(struct usb_ep *_ep)
{
        struct dwc2_ep *ep;
        unsigned long flags = 0;

        debug("%s: %p\n", __func__, _ep);

        ep = container_of(_ep, struct dwc2_ep, ep);
        if (!_ep || !ep->desc) {
                debug("%s: %s not enabled\n", __func__,
                      _ep ? ep->ep.name : NULL);
                return -EINVAL;
        }

        spin_lock_irqsave(&ep->dev->lock, flags);

        /* Nuke all pending requests */
        nuke(ep, -ESHUTDOWN);

        _ep->desc = NULL;
        ep->desc = 0;
        ep->stopped = 1;

        spin_unlock_irqrestore(&ep->dev->lock, flags);

        debug("%s: disabled %s\n", __func__, _ep->name);
        return 0;
}

static struct usb_request *dwc2_alloc_request(struct usb_ep *ep,
                                             gfp_t gfp_flags)
{
        struct dwc2_request *req;

        debug("%s: %s %p\n", __func__, ep->name, ep);

        req = memalign(CONFIG_SYS_CACHELINE_SIZE, sizeof(*req));
        if (!req)
                return 0;

        memset(req, 0, sizeof *req);
        INIT_LIST_HEAD(&req->queue);

        return &req->req;
}

static void dwc2_free_request(struct usb_ep *ep, struct usb_request *_req)
{
        struct dwc2_request *req;

        debug("%s: %p\n", __func__, ep);

        req = container_of(_req, struct dwc2_request, req);
        WARN_ON(!list_empty(&req->queue));
        kfree(req);
}

/* dequeue JUST ONE request */
static int dwc2_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
        struct dwc2_ep *ep;
        struct dwc2_request *req;
        unsigned long flags = 0;

        debug("%s: %p\n", __func__, _ep);

        ep = container_of(_ep, struct dwc2_ep, ep);
        if (!_ep || ep->ep.name == ep0name)
                return -EINVAL;

        spin_lock_irqsave(&ep->dev->lock, flags);

        /* make sure it's actually queued on this endpoint */
        list_for_each_entry(req, &ep->queue, queue) {
                if (&req->req == _req)
                        break;
        }
        if (&req->req != _req) {
                spin_unlock_irqrestore(&ep->dev->lock, flags);
                return -EINVAL;
        }

        done(ep, req, -ECONNRESET);

        spin_unlock_irqrestore(&ep->dev->lock, flags);
        return 0;
}

/*
 * Return bytes in EP FIFO
 */
static int dwc2_fifo_status(struct usb_ep *_ep)
{
        int count = 0;
        struct dwc2_ep *ep;

        ep = container_of(_ep, struct dwc2_ep, ep);
        if (!_ep) {
                debug("%s: bad ep\n", __func__);
                return -ENODEV;
        }

        debug("%s: %d\n", __func__, ep_index(ep));

        /* LPD can't report unclaimed bytes from IN fifos */
        if (ep_is_in(ep))
                return -EOPNOTSUPP;

        return count;
}

/*
 * Flush EP FIFO
 */
static void dwc2_fifo_flush(struct usb_ep *_ep)
{
        struct dwc2_ep *ep;

        ep = container_of(_ep, struct dwc2_ep, ep);
        if (unlikely(!_ep || (!ep->desc && ep->ep.name != ep0name))) {
                debug("%s: bad ep\n", __func__);
                return;
        }

        debug("%s: %d\n", __func__, ep_index(ep));
}

static const struct usb_gadget_ops dwc2_udc_ops = {
        /* current versions must always be self-powered */
#if CONFIG_IS_ENABLED(DM_USB_GADGET)
        .udc_start              = dwc2_gadget_start,
        .udc_stop               = dwc2_gadget_stop,
#endif
};

static struct dwc2_udc memory = {
        .usb_address = 0,
        .gadget = {
                .ops = &dwc2_udc_ops,
                .ep0 = &memory.ep[0].ep,
                .name = driver_name,
        },

        /* control endpoint */
        .ep[0] = {
                .ep = {
                        .name = ep0name,
                        .ops = &dwc2_ep_ops,
                        .maxpacket = EP0_FIFO_SIZE,
                },
                .dev = &memory,

                .bEndpointAddress = 0,
                .bmAttributes = 0,

                .ep_type = ep_control,
        },

        /* first group of endpoints */
        .ep[1] = {
                .ep = {
                        .name = "ep1in-bulk",
                        .ops = &dwc2_ep_ops,
                        .maxpacket = EP_FIFO_SIZE,
                },
                .dev = &memory,

                .bEndpointAddress = USB_DIR_IN | 1,
                .bmAttributes = USB_ENDPOINT_XFER_BULK,

                .ep_type = ep_bulk_out,
                .fifo_num = 1,
        },

        .ep[2] = {
                .ep = {
                        .name = "ep2out-bulk",
                        .ops = &dwc2_ep_ops,
                        .maxpacket = EP_FIFO_SIZE,
                },
                .dev = &memory,

                .bEndpointAddress = USB_DIR_OUT | 2,
                .bmAttributes = USB_ENDPOINT_XFER_BULK,

                .ep_type = ep_bulk_in,
                .fifo_num = 2,
        },

        .ep[3] = {
                .ep = {
                        .name = "ep3in-int",
                        .ops = &dwc2_ep_ops,
                        .maxpacket = EP_FIFO_SIZE,
                },
                .dev = &memory,

                .bEndpointAddress = USB_DIR_IN | 3,
                .bmAttributes = USB_ENDPOINT_XFER_INT,

                .ep_type = ep_interrupt,
                .fifo_num = 3,
        },
};

/*
 *      probe - binds to the platform device
 */

int dwc2_udc_probe(struct dwc2_plat_otg_data *pdata)
{
        struct dwc2_udc *dev = &memory;
        int retval = 0;

        debug("%s: %p\n", __func__, pdata);

        dev->pdata = pdata;

        reg = (struct dwc2_usbotg_reg *)pdata->regs_otg;

        dev->gadget.is_dualspeed = 1;   /* Hack only*/
        dev->gadget.is_otg = 0;
        dev->gadget.is_a_peripheral = 0;
        dev->gadget.b_hnp_enable = 0;
        dev->gadget.a_hnp_support = 0;
        dev->gadget.a_alt_hnp_support = 0;

        the_controller = dev;

        usb_ctrl = memalign(CONFIG_SYS_CACHELINE_SIZE,
                            ROUND(sizeof(struct usb_ctrlrequest),
                                  CONFIG_SYS_CACHELINE_SIZE));
        if (!usb_ctrl) {
                pr_err("No memory available for UDC!\n");
                return -ENOMEM;
        }

        usb_ctrl_dma_addr = (dma_addr_t) usb_ctrl;

        udc_reinit(dev);

        return retval;
}

int dwc2_udc_handle_interrupt(void)
{
        u32 intr_status = readl(&reg->gintsts);
        u32 gintmsk = readl(&reg->gintmsk);

        if (intr_status & gintmsk)
                return dwc2_udc_irq(1, (void *)the_controller);

        return 0;
}

#if !CONFIG_IS_ENABLED(DM_USB_GADGET)

int usb_gadget_handle_interrupts(int index)
{
        return dwc2_udc_handle_interrupt();
}

#else /* CONFIG_IS_ENABLED(DM_USB_GADGET) */

struct dwc2_priv_data {
        struct clk_bulk         clks;
        struct reset_ctl_bulk   resets;
        struct phy_bulk phys;
        struct udevice *usb33d_supply;
};

int dm_usb_gadget_handle_interrupts(struct udevice *dev)
{
        return dwc2_udc_handle_interrupt();
}

static int dwc2_phy_setup(struct udevice *dev, struct phy_bulk *phys)
{
        int ret;

        ret = generic_phy_get_bulk(dev, phys);
        if (ret)
                return ret;

        ret = generic_phy_init_bulk(phys);
        if (ret)
                return ret;

        ret = generic_phy_power_on_bulk(phys);
        if (ret)
                generic_phy_exit_bulk(phys);

        return ret;
}

static void dwc2_phy_shutdown(struct udevice *dev, struct phy_bulk *phys)
{
        generic_phy_power_off_bulk(phys);
        generic_phy_exit_bulk(phys);
}

static int dwc2_udc_otg_of_to_plat(struct udevice *dev)
{
        struct dwc2_plat_otg_data *plat = dev_get_plat(dev);
        ulong drvdata;
        void (*set_params)(struct dwc2_plat_otg_data *data);
        int ret;

        if (usb_get_dr_mode(dev_ofnode(dev)) != USB_DR_MODE_PERIPHERAL &&
            usb_get_dr_mode(dev_ofnode(dev)) != USB_DR_MODE_OTG) {
                dev_dbg(dev, "Invalid mode\n");
                return -ENODEV;
        }

        plat->regs_otg = dev_read_addr(dev);

        plat->rx_fifo_sz = dev_read_u32_default(dev, "g-rx-fifo-size", 0);
        plat->np_tx_fifo_sz = dev_read_u32_default(dev, "g-np-tx-fifo-size", 0);

        plat->tx_fifo_sz_nb =
                dev_read_size(dev, "g-tx-fifo-size") / sizeof(u32);

        if (plat->tx_fifo_sz_nb > DWC2_MAX_HW_ENDPOINTS)
                plat->tx_fifo_sz_nb = DWC2_MAX_HW_ENDPOINTS;
        if (plat->tx_fifo_sz_nb) {
                ret = dev_read_u32_array(dev, "g-tx-fifo-size",
                                         plat->tx_fifo_sz_array,
                                         plat->tx_fifo_sz_nb);
                if (ret)
                        return ret;
        }

        plat->force_b_session_valid =
                dev_read_bool(dev, "u-boot,force-b-session-valid");

        plat->force_vbus_detection =
                dev_read_bool(dev, "u-boot,force-vbus-detection");

        /* force plat according compatible */
        drvdata = dev_get_driver_data(dev);
        if (drvdata) {
                set_params = (void *)drvdata;
                set_params(plat);
        }

        return 0;
}

static void dwc2_set_stm32mp1_hsotg_params(struct dwc2_plat_otg_data *p)
{
        p->activate_stm_id_vb_detection = true;
        p->usb_gusbcfg =
                0 << 15         /* PHY Low Power Clock sel*/
                | 0x9 << 10     /* USB Turnaround time (0x9 for HS phy) */
                | 0 << 9        /* [0:HNP disable,1:HNP enable]*/
                | 0 << 8        /* [0:SRP disable 1:SRP enable]*/
                | 0 << 6        /* 0: high speed utmi+, 1: full speed serial*/
                | 0x7 << 0;     /* FS timeout calibration**/

        if (p->force_b_session_valid)
                p->usb_gusbcfg |= 1 << 30; /* FDMOD: Force device mode */
}

static int dwc2_udc_otg_reset_init(struct udevice *dev,
                                   struct reset_ctl_bulk *resets)
{
        int ret;

        ret = reset_get_bulk(dev, resets);
        if (ret == -ENOTSUPP || ret == -ENOENT)
                return 0;

        if (ret)
                return ret;

        ret = reset_assert_bulk(resets);

        if (!ret) {
                udelay(2);
                ret = reset_deassert_bulk(resets);
        }
        if (ret) {
                reset_release_bulk(resets);
                return ret;
        }

        return 0;
}

static int dwc2_udc_otg_clk_init(struct udevice *dev,
                                 struct clk_bulk *clks)
{
        int ret;

        ret = clk_get_bulk(dev, clks);
        if (ret == -ENOSYS)
                return 0;

        if (ret)
                return ret;

        ret = clk_enable_bulk(clks);
        if (ret) {
                clk_release_bulk(clks);
                return ret;
        }

        return 0;
}

static int dwc2_udc_otg_probe(struct udevice *dev)
{
        struct dwc2_plat_otg_data *plat = dev_get_plat(dev);
        struct dwc2_priv_data *priv = dev_get_priv(dev);
        struct dwc2_usbotg_reg *usbotg_reg =
                (struct dwc2_usbotg_reg *)plat->regs_otg;
        int ret;

        ret = dwc2_udc_otg_clk_init(dev, &priv->clks);
        if (ret)
                return ret;

        ret = dwc2_udc_otg_reset_init(dev, &priv->resets);
        if (ret)
                return ret;

        ret = dwc2_phy_setup(dev, &priv->phys);
        if (ret)
                return ret;

        if (plat->activate_stm_id_vb_detection) {
                if (CONFIG_IS_ENABLED(DM_REGULATOR) &&
                    (!plat->force_b_session_valid ||
                     plat->force_vbus_detection)) {
                        ret = device_get_supply_regulator(dev, "usb33d-supply",
                                                          &priv->usb33d_supply);
                        if (ret) {
                                dev_err(dev, "can't get voltage level detector supply\n");
                                return ret;
                        }
                        ret = regulator_set_enable(priv->usb33d_supply, true);
                        if (ret) {
                                dev_err(dev, "can't enable voltage level detector supply\n");
                                return ret;
                        }
                }

                if (plat->force_b_session_valid &&
                    !plat->force_vbus_detection) {
                        /* Override VBUS detection: enable then value*/
                        setbits_le32(&usbotg_reg->gotgctl, VB_VALOEN);
                        setbits_le32(&usbotg_reg->gotgctl, VB_VALOVAL);
                } else {
                        /* Enable VBUS sensing */
                        setbits_le32(&usbotg_reg->ggpio,
                                     GGPIO_STM32_OTG_GCCFG_VBDEN);
                }
                if (plat->force_b_session_valid) {
                        /* Override B session bits: enable then value */
                        setbits_le32(&usbotg_reg->gotgctl, A_VALOEN | B_VALOEN);
                        setbits_le32(&usbotg_reg->gotgctl,
                                     A_VALOVAL | B_VALOVAL);
                } else {
                        /* Enable ID detection */
                        setbits_le32(&usbotg_reg->ggpio,
                                     GGPIO_STM32_OTG_GCCFG_IDEN);
                }
        }

        ret = dwc2_udc_probe(plat);
        if (ret)
                return ret;

        the_controller->driver = 0;

        ret = usb_add_gadget_udc((struct device *)dev, &the_controller->gadget);

        return ret;
}

static int dwc2_udc_otg_remove(struct udevice *dev)
{
        struct dwc2_priv_data *priv = dev_get_priv(dev);

        usb_del_gadget_udc(&the_controller->gadget);

        reset_release_bulk(&priv->resets);

        clk_release_bulk(&priv->clks);

        dwc2_phy_shutdown(dev, &priv->phys);

        return dm_scan_fdt_dev(dev);
}

static const struct udevice_id dwc2_udc_otg_ids[] = {
        { .compatible = "snps,dwc2" },
        { .compatible = "brcm,bcm2835-usb" },
        { .compatible = "st,stm32mp15-hsotg",
          .data = (ulong)dwc2_set_stm32mp1_hsotg_params },
        {},
};

U_BOOT_DRIVER(dwc2_udc_otg) = {
        .name   = "dwc2-udc-otg",
        .id     = UCLASS_USB_GADGET_GENERIC,
        .of_match = dwc2_udc_otg_ids,
        .of_to_plat = dwc2_udc_otg_of_to_plat,
        .probe = dwc2_udc_otg_probe,
        .remove = dwc2_udc_otg_remove,
        .plat_auto      = sizeof(struct dwc2_plat_otg_data),
        .priv_auto      = sizeof(struct dwc2_priv_data),
};

int dwc2_udc_B_session_valid(struct udevice *dev)
{
        struct dwc2_plat_otg_data *plat = dev_get_plat(dev);
        struct dwc2_usbotg_reg *usbotg_reg =
                (struct dwc2_usbotg_reg *)plat->regs_otg;

        return readl(&usbotg_reg->gotgctl) & B_SESSION_VALID;
}
#endif /* CONFIG_IS_ENABLED(DM_USB_GADGET) */