Quelle  cdns3-ep0.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/*
 * Cadence USBSS DRD Driver - gadget side.
 *
 * Copyright (C) 2018 Cadence Design Systems.
 * Copyright (C) 2017-2018 NXP
 *
 * Authors: Pawel Jez <pjez@cadence.com>,
 *          Pawel Laszczak <pawell@cadence.com>
 *          Peter Chen <peter.chen@nxp.com>
 */

#include <linux/usb/composite.h>
#include <linux/iopoll.h>

#include "cdns3-gadget.h"
#include "cdns3-trace.h"

static struct usb_endpoint_descriptor cdns3_gadget_ep0_desc = {
 .bLength = USB_DT_ENDPOINT_SIZE,
 .bDescriptorType = USB_DT_ENDPOINT,
 .bmAttributes = USB_ENDPOINT_XFER_CONTROL,
};

/**
 * cdns3_ep0_run_transfer - Do transfer on default endpoint hardware
 * @priv_dev: extended gadget object
 * @dma_addr: physical address where data is/will be stored
 * @length: data length
 * @erdy: set it to 1 when ERDY packet should be sent -
 *        exit from flow control state
 * @zlp: add zero length packet
 */
static void cdns3_ep0_run_transfer(struct cdns3_device *priv_dev,
       dma_addr_t dma_addr,
       unsigned int length, int erdy, int zlp)
{
 struct cdns3_usb_regs __iomem *regs = priv_dev->regs;
 struct cdns3_endpoint *priv_ep = priv_dev->eps[0];

 priv_ep->trb_pool[0].buffer = cpu_to_le32(TRB_BUFFER(dma_addr));
 priv_ep->trb_pool[0].length = cpu_to_le32(TRB_LEN(length));

 if (zlp) {
  priv_ep->trb_pool[0].control = cpu_to_le32(TRB_CYCLE | TRB_TYPE(TRB_NORMAL));
  priv_ep->trb_pool[1].buffer = cpu_to_le32(TRB_BUFFER(dma_addr));
  priv_ep->trb_pool[1].length = cpu_to_le32(TRB_LEN(0));
  priv_ep->trb_pool[1].control = cpu_to_le32(TRB_CYCLE | TRB_IOC |
      TRB_TYPE(TRB_NORMAL));
 } else {
  priv_ep->trb_pool[0].control = cpu_to_le32(TRB_CYCLE | TRB_IOC |
      TRB_TYPE(TRB_NORMAL));
  priv_ep->trb_pool[1].control = 0;
 }

 trace_cdns3_prepare_trb(priv_ep, priv_ep->trb_pool);

 cdns3_select_ep(priv_dev, priv_dev->ep0_data_dir);

 writel(EP_STS_TRBERR, ®s->ep_sts);
 writel(EP_TRADDR_TRADDR(priv_ep->trb_pool_dma), ®s->ep_traddr);
 trace_cdns3_doorbell_ep0(priv_dev->ep0_data_dir ? "ep0in" : "ep0out",
     readl(®s->ep_traddr));

 /* TRB should be prepared before starting transfer. */
 writel(EP_CMD_DRDY, ®s->ep_cmd);

 /* Resume controller before arming transfer. */
 __cdns3_gadget_wakeup(priv_dev);

 if (erdy)
  writel(EP_CMD_ERDY, &priv_dev->regs->ep_cmd);
}

/**
 * cdns3_ep0_delegate_req - Returns status of handling setup packet
 * Setup is handled by gadget driver
 * @priv_dev: extended gadget object
 * @ctrl_req: pointer to received setup packet
 *
 * Returns zero on success or negative value on failure
 */
static int cdns3_ep0_delegate_req(struct cdns3_device *priv_dev,
      struct usb_ctrlrequest *ctrl_req)
{
 int ret;

 spin_unlock(&priv_dev->lock);
 priv_dev->setup_pending = 1;
 ret = priv_dev->gadget_driver->setup(&priv_dev->gadget, ctrl_req);
 priv_dev->setup_pending = 0;
 spin_lock(&priv_dev->lock);
 return ret;
}

static void cdns3_prepare_setup_packet(struct cdns3_device *priv_dev)
{
 priv_dev->ep0_data_dir = 0;
 priv_dev->ep0_stage = CDNS3_SETUP_STAGE;
 cdns3_ep0_run_transfer(priv_dev, priv_dev->setup_dma,
          sizeof(struct usb_ctrlrequest), 0, 0);
}

static void cdns3_ep0_complete_setup(struct cdns3_device *priv_dev,
         u8 send_stall, u8 send_erdy)
{
 struct cdns3_endpoint *priv_ep = priv_dev->eps[0];
 struct usb_request *request;

 request = cdns3_next_request(&priv_ep->pending_req_list);
 if (request)
  list_del_init(&request->list);

 if (send_stall) {
  trace_cdns3_halt(priv_ep, send_stall, 0);
  /* set_stall on ep0 */
  cdns3_select_ep(priv_dev, 0x00);
  writel(EP_CMD_SSTALL, &priv_dev->regs->ep_cmd);
 } else {
  cdns3_prepare_setup_packet(priv_dev);
 }

 priv_dev->ep0_stage = CDNS3_SETUP_STAGE;
 writel((send_erdy ? EP_CMD_ERDY : 0) | EP_CMD_REQ_CMPL,
        &priv_dev->regs->ep_cmd);
}

/**
 * cdns3_req_ep0_set_configuration - Handling of SET_CONFIG standard USB request
 * @priv_dev: extended gadget object
 * @ctrl_req: pointer to received setup packet
 *
 * Returns 0 if success, USB_GADGET_DELAYED_STATUS on deferred status stage,
 * error code on error
 */
static int cdns3_req_ep0_set_configuration(struct cdns3_device *priv_dev,
        struct usb_ctrlrequest *ctrl_req)
{
 enum usb_device_state device_state = priv_dev->gadget.state;
 u32 config = le16_to_cpu(ctrl_req->wValue);
 int result = 0;

 switch (device_state) {
 case USB_STATE_ADDRESS:
  result = cdns3_ep0_delegate_req(priv_dev, ctrl_req);

  if (result || !config)
   goto reset_config;

  break;
 case USB_STATE_CONFIGURED:
  result = cdns3_ep0_delegate_req(priv_dev, ctrl_req);
  if (!config && !result)
   goto reset_config;

  break;
 default:
  return -EINVAL;
 }

 return 0;

reset_config:
 if (result != USB_GADGET_DELAYED_STATUS)
  cdns3_hw_reset_eps_config(priv_dev);

 usb_gadget_set_state(&priv_dev->gadget,
        USB_STATE_ADDRESS);

 return result;
}

/**
 * cdns3_req_ep0_set_address - Handling of SET_ADDRESS standard USB request
 * @priv_dev: extended gadget object
 * @ctrl_req: pointer to received setup packet
 *
 * Returns 0 if success, error code on error
 */
static int cdns3_req_ep0_set_address(struct cdns3_device *priv_dev,
         struct usb_ctrlrequest *ctrl_req)
{
 enum usb_device_state device_state = priv_dev->gadget.state;
 u32 reg;
 u32 addr;

 addr = le16_to_cpu(ctrl_req->wValue);

 if (addr > USB_DEVICE_MAX_ADDRESS) {
  dev_err(priv_dev->dev,
   "Device address (%d) cannot be greater than %d\n",
   addr, USB_DEVICE_MAX_ADDRESS);
  return -EINVAL;
 }

 if (device_state == USB_STATE_CONFIGURED) {
  dev_err(priv_dev->dev,
   "can't set_address from configured state\n");
  return -EINVAL;
 }

 reg = readl(&priv_dev->regs->usb_cmd);

 writel(reg | USB_CMD_FADDR(addr) | USB_CMD_SET_ADDR,
        &priv_dev->regs->usb_cmd);

 usb_gadget_set_state(&priv_dev->gadget,
        (addr ? USB_STATE_ADDRESS : USB_STATE_DEFAULT));

 return 0;
}

/**
 * cdns3_req_ep0_get_status - Handling of GET_STATUS standard USB request
 * @priv_dev: extended gadget object
 * @ctrl: pointer to received setup packet
 *
 * Returns 0 if success, error code on error
 */
static int cdns3_req_ep0_get_status(struct cdns3_device *priv_dev,
        struct usb_ctrlrequest *ctrl)
{
 struct cdns3_endpoint *priv_ep;
 __le16 *response_pkt;
 u16 usb_status = 0;
 u32 recip;
 u8 index;

 recip = ctrl->bRequestType & USB_RECIP_MASK;

 switch (recip) {
 case USB_RECIP_DEVICE:
  /* self powered */
  if (priv_dev->is_selfpowered)
   usb_status = BIT(USB_DEVICE_SELF_POWERED);

  if (priv_dev->wake_up_flag)
   usb_status |= BIT(USB_DEVICE_REMOTE_WAKEUP);

  if (priv_dev->gadget.speed != USB_SPEED_SUPER)
   break;

  if (priv_dev->u1_allowed)
   usb_status |= BIT(USB_DEV_STAT_U1_ENABLED);

  if (priv_dev->u2_allowed)
   usb_status |= BIT(USB_DEV_STAT_U2_ENABLED);

  break;
 case USB_RECIP_INTERFACE:
  return cdns3_ep0_delegate_req(priv_dev, ctrl);
 case USB_RECIP_ENDPOINT:
  index = cdns3_ep_addr_to_index(le16_to_cpu(ctrl->wIndex));
  priv_ep = priv_dev->eps[index];

  /* check if endpoint is stalled or stall is pending */
  cdns3_select_ep(priv_dev, le16_to_cpu(ctrl->wIndex));
  if (EP_STS_STALL(readl(&priv_dev->regs->ep_sts)) ||
      (priv_ep->flags & EP_STALL_PENDING))
   usb_status =  BIT(USB_ENDPOINT_HALT);
  break;
 default:
  return -EINVAL;
 }

 response_pkt = (__le16 *)priv_dev->setup_buf;
 *response_pkt = cpu_to_le16(usb_status);

 cdns3_ep0_run_transfer(priv_dev, priv_dev->setup_dma,
          sizeof(*response_pkt), 1, 0);
 return 0;
}

static int cdns3_ep0_feature_handle_device(struct cdns3_device *priv_dev,
        struct usb_ctrlrequest *ctrl,
        int set)
{
 enum usb_device_state state;
 enum usb_device_speed speed;
 int ret = 0;
 u32 wValue;
 u16 tmode;

 wValue = le16_to_cpu(ctrl->wValue);
 state = priv_dev->gadget.state;
 speed = priv_dev->gadget.speed;

 switch (wValue) {
 case USB_DEVICE_REMOTE_WAKEUP:
  priv_dev->wake_up_flag = !!set;
  break;
 case USB_DEVICE_U1_ENABLE:
  if (state != USB_STATE_CONFIGURED || speed != USB_SPEED_SUPER)
   return -EINVAL;

  priv_dev->u1_allowed = !!set;
  break;
 case USB_DEVICE_U2_ENABLE:
  if (state != USB_STATE_CONFIGURED || speed != USB_SPEED_SUPER)
   return -EINVAL;

  priv_dev->u2_allowed = !!set;
  break;
 case USB_DEVICE_LTM_ENABLE:
  ret = -EINVAL;
  break;
 case USB_DEVICE_TEST_MODE:
  if (state != USB_STATE_CONFIGURED || speed > USB_SPEED_HIGH)
   return -EINVAL;

  tmode = le16_to_cpu(ctrl->wIndex);

  if (!set || (tmode & 0xff) != 0)
   return -EINVAL;

  tmode >>= 8;
  switch (tmode) {
  case USB_TEST_J:
  case USB_TEST_K:
  case USB_TEST_SE0_NAK:
  case USB_TEST_PACKET:
   cdns3_set_register_bit(&priv_dev->regs->usb_cmd,
            USB_CMD_STMODE |
            USB_STS_TMODE_SEL(tmode - 1));
   break;
  default:
   ret = -EINVAL;
  }
  break;
 default:
  ret = -EINVAL;
 }

 return ret;
}

static int cdns3_ep0_feature_handle_intf(struct cdns3_device *priv_dev,
      struct usb_ctrlrequest *ctrl,
      int set)
{
 u32 wValue;
 int ret = 0;

 wValue = le16_to_cpu(ctrl->wValue);

 switch (wValue) {
 case USB_INTRF_FUNC_SUSPEND:
  break;
 default:
  ret = -EINVAL;
 }

 return ret;
}

static int cdns3_ep0_feature_handle_endpoint(struct cdns3_device *priv_dev,
          struct usb_ctrlrequest *ctrl,
          int set)
{
 struct cdns3_endpoint *priv_ep;
 int ret = 0;
 u8 index;

 if (le16_to_cpu(ctrl->wValue) != USB_ENDPOINT_HALT)
  return -EINVAL;

 if (!(le16_to_cpu(ctrl->wIndex) & ~USB_DIR_IN))
  return 0;

 index = cdns3_ep_addr_to_index(le16_to_cpu(ctrl->wIndex));
 priv_ep = priv_dev->eps[index];

 cdns3_select_ep(priv_dev, le16_to_cpu(ctrl->wIndex));

 if (set)
  __cdns3_gadget_ep_set_halt(priv_ep);
 else if (!(priv_ep->flags & EP_WEDGE))
  ret = __cdns3_gadget_ep_clear_halt(priv_ep);

 cdns3_select_ep(priv_dev, 0x00);

 return ret;
}

/**
 * cdns3_req_ep0_handle_feature -
 * Handling of GET/SET_FEATURE standard USB request
 *
 * @priv_dev: extended gadget object
 * @ctrl: pointer to received setup packet
 * @set: must be set to 1 for SET_FEATURE request
 *
 * Returns 0 if success, error code on error
 */
static int cdns3_req_ep0_handle_feature(struct cdns3_device *priv_dev,
     struct usb_ctrlrequest *ctrl,
     int set)
{
 int ret = 0;
 u32 recip;

 recip = ctrl->bRequestType & USB_RECIP_MASK;

 switch (recip) {
 case USB_RECIP_DEVICE:
  ret = cdns3_ep0_feature_handle_device(priv_dev, ctrl, set);
  break;
 case USB_RECIP_INTERFACE:
  ret = cdns3_ep0_feature_handle_intf(priv_dev, ctrl, set);
  break;
 case USB_RECIP_ENDPOINT:
  ret = cdns3_ep0_feature_handle_endpoint(priv_dev, ctrl, set);
  break;
 default:
  return -EINVAL;
 }

 return ret;
}

/**
 * cdns3_req_ep0_set_sel - Handling of SET_SEL standard USB request
 * @priv_dev: extended gadget object
 * @ctrl_req: pointer to received setup packet
 *
 * Returns 0 if success, error code on error
 */
static int cdns3_req_ep0_set_sel(struct cdns3_device *priv_dev,
     struct usb_ctrlrequest *ctrl_req)
{
 if (priv_dev->gadget.state < USB_STATE_ADDRESS)
  return -EINVAL;

 if (le16_to_cpu(ctrl_req->wLength) != 6) {
  dev_err(priv_dev->dev, "Set SEL should be 6 bytes, got %d\n",
   ctrl_req->wLength);
  return -EINVAL;
 }

 cdns3_ep0_run_transfer(priv_dev, priv_dev->setup_dma, 6, 1, 0);
 return 0;
}

/**
 * cdns3_req_ep0_set_isoch_delay -
 * Handling of GET_ISOCH_DELAY standard USB request
 * @priv_dev: extended gadget object
 * @ctrl_req: pointer to received setup packet
 *
 * Returns 0 if success, error code on error
 */
static int cdns3_req_ep0_set_isoch_delay(struct cdns3_device *priv_dev,
      struct usb_ctrlrequest *ctrl_req)
{
 if (ctrl_req->wIndex || ctrl_req->wLength)
  return -EINVAL;

 priv_dev->isoch_delay = le16_to_cpu(ctrl_req->wValue);

 return 0;
}

/**
 * cdns3_ep0_standard_request - Handling standard USB requests
 * @priv_dev: extended gadget object
 * @ctrl_req: pointer to received setup packet
 *
 * Returns 0 if success, error code on error
 */
static int cdns3_ep0_standard_request(struct cdns3_device *priv_dev,
          struct usb_ctrlrequest *ctrl_req)
{
 int ret;

 switch (ctrl_req->bRequest) {
 case USB_REQ_SET_ADDRESS:
  ret = cdns3_req_ep0_set_address(priv_dev, ctrl_req);
  break;
 case USB_REQ_SET_CONFIGURATION:
  ret = cdns3_req_ep0_set_configuration(priv_dev, ctrl_req);
  break;
 case USB_REQ_GET_STATUS:
  ret = cdns3_req_ep0_get_status(priv_dev, ctrl_req);
  break;
 case USB_REQ_CLEAR_FEATURE:
  ret = cdns3_req_ep0_handle_feature(priv_dev, ctrl_req, 0);
  break;
 case USB_REQ_SET_FEATURE:
  ret = cdns3_req_ep0_handle_feature(priv_dev, ctrl_req, 1);
  break;
 case USB_REQ_SET_SEL:
  ret = cdns3_req_ep0_set_sel(priv_dev, ctrl_req);
  break;
 case USB_REQ_SET_ISOCH_DELAY:
  ret = cdns3_req_ep0_set_isoch_delay(priv_dev, ctrl_req);
  break;
 default:
  ret = cdns3_ep0_delegate_req(priv_dev, ctrl_req);
  break;
 }

 return ret;
}

static void __pending_setup_status_handler(struct cdns3_device *priv_dev)
{
 struct usb_request *request = priv_dev->pending_status_request;

 if (priv_dev->status_completion_no_call && request &&
     request->complete) {
  request->complete(&priv_dev->eps[0]->endpoint, request);
  priv_dev->status_completion_no_call = 0;
 }
}

void cdns3_pending_setup_status_handler(struct work_struct *work)
{
 struct cdns3_device *priv_dev = container_of(work, struct cdns3_device,
   pending_status_wq);
 unsigned long flags;

 spin_lock_irqsave(&priv_dev->lock, flags);
 __pending_setup_status_handler(priv_dev);
 spin_unlock_irqrestore(&priv_dev->lock, flags);
}

/**
 * cdns3_ep0_setup_phase - Handling setup USB requests
 * @priv_dev: extended gadget object
 */
static void cdns3_ep0_setup_phase(struct cdns3_device *priv_dev)
{
 struct usb_ctrlrequest *ctrl = priv_dev->setup_buf;
 struct cdns3_endpoint *priv_ep = priv_dev->eps[0];
 int result;

 priv_dev->ep0_data_dir = ctrl->bRequestType & USB_DIR_IN;

 trace_cdns3_ctrl_req(ctrl);

 if (!list_empty(&priv_ep->pending_req_list)) {
  struct usb_request *request;

  request = cdns3_next_request(&priv_ep->pending_req_list);
  priv_ep->dir = priv_dev->ep0_data_dir;
  cdns3_gadget_giveback(priv_ep, to_cdns3_request(request),
          -ECONNRESET);
 }

 if (le16_to_cpu(ctrl->wLength))
  priv_dev->ep0_stage = CDNS3_DATA_STAGE;
 else
  priv_dev->ep0_stage = CDNS3_STATUS_STAGE;

 if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
  result = cdns3_ep0_standard_request(priv_dev, ctrl);
 else
  result = cdns3_ep0_delegate_req(priv_dev, ctrl);

 if (result == USB_GADGET_DELAYED_STATUS)
  return;

 if (result < 0)
  cdns3_ep0_complete_setup(priv_dev, 1, 1);
 else if (priv_dev->ep0_stage == CDNS3_STATUS_STAGE)
  cdns3_ep0_complete_setup(priv_dev, 0, 1);
}

static void cdns3_transfer_completed(struct cdns3_device *priv_dev)
{
 struct cdns3_endpoint *priv_ep = priv_dev->eps[0];

 if (!list_empty(&priv_ep->pending_req_list)) {
  struct usb_request *request;

  trace_cdns3_complete_trb(priv_ep, priv_ep->trb_pool);
  request = cdns3_next_request(&priv_ep->pending_req_list);

  request->actual =
   TRB_LEN(le32_to_cpu(priv_ep->trb_pool->length));

  priv_ep->dir = priv_dev->ep0_data_dir;
  cdns3_gadget_giveback(priv_ep, to_cdns3_request(request), 0);
 }

 cdns3_ep0_complete_setup(priv_dev, 0, 0);
}

/**
 * cdns3_check_new_setup - Check if controller receive new SETUP packet.
 * @priv_dev: extended gadget object
 *
 * The SETUP packet can be kept in on-chip memory or in system memory.
 */
static bool cdns3_check_new_setup(struct cdns3_device *priv_dev)
{
 u32 ep_sts_reg;

 cdns3_select_ep(priv_dev, USB_DIR_OUT);
 ep_sts_reg = readl(&priv_dev->regs->ep_sts);

 return !!(ep_sts_reg & (EP_STS_SETUP | EP_STS_STPWAIT));
}

/**
 * cdns3_check_ep0_interrupt_proceed - Processes interrupt related to endpoint 0
 * @priv_dev: extended gadget object
 * @dir: USB_DIR_IN for IN direction, USB_DIR_OUT for OUT direction
 */
void cdns3_check_ep0_interrupt_proceed(struct cdns3_device *priv_dev, int dir)
{
 u32 ep_sts_reg;

 cdns3_select_ep(priv_dev, dir);

 ep_sts_reg = readl(&priv_dev->regs->ep_sts);
 writel(ep_sts_reg, &priv_dev->regs->ep_sts);

 trace_cdns3_ep0_irq(priv_dev, ep_sts_reg);

 __pending_setup_status_handler(priv_dev);

 if (ep_sts_reg & EP_STS_SETUP)
  priv_dev->wait_for_setup = 1;

 if (priv_dev->wait_for_setup && ep_sts_reg & EP_STS_IOC) {
  priv_dev->wait_for_setup = 0;
  cdns3_ep0_setup_phase(priv_dev);
 } else if ((ep_sts_reg & EP_STS_IOC) || (ep_sts_reg & EP_STS_ISP)) {
  priv_dev->ep0_data_dir = dir;
  cdns3_transfer_completed(priv_dev);
 }

 if (ep_sts_reg & EP_STS_DESCMIS) {
  if (dir == 0 && !priv_dev->setup_pending)
   cdns3_prepare_setup_packet(priv_dev);
 }
}

/**
 * cdns3_gadget_ep0_enable
 * @ep: pointer to endpoint zero object
 * @desc: pointer to usb endpoint descriptor
 *
 * Function shouldn't be called by gadget driver,
 * endpoint 0 is allways active
 */
static int cdns3_gadget_ep0_enable(struct usb_ep *ep,
       const struct usb_endpoint_descriptor *desc)
{
 return -EINVAL;
}

/**
 * cdns3_gadget_ep0_disable
 * @ep: pointer to endpoint zero object
 *
 * Function shouldn't be called by gadget driver,
 * endpoint 0 is allways active
 */
static int cdns3_gadget_ep0_disable(struct usb_ep *ep)
{
 return -EINVAL;
}

/**
 * cdns3_gadget_ep0_set_halt
 * @ep: pointer to endpoint zero object
 * @value: 1 for set stall, 0 for clear stall
 *
 * Returns 0
 */
static int cdns3_gadget_ep0_set_halt(struct usb_ep *ep, int value)
{
 /* TODO */
 return 0;
}

/**
 * cdns3_gadget_ep0_queue - Transfer data on endpoint zero
 * @ep: pointer to endpoint zero object
 * @request: pointer to request object
 * @gfp_flags: gfp flags
 *
 * Returns 0 on success, error code elsewhere
 */
static int cdns3_gadget_ep0_queue(struct usb_ep *ep,
      struct usb_request *request,
      gfp_t gfp_flags)
{
 struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
 struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
 unsigned long flags;
 int ret = 0;
 u8 zlp = 0;
 int i;

 spin_lock_irqsave(&priv_dev->lock, flags);
 trace_cdns3_ep0_queue(priv_dev, request);

 /* cancel the request if controller receive new SETUP packet. */
 if (cdns3_check_new_setup(priv_dev)) {
  spin_unlock_irqrestore(&priv_dev->lock, flags);
  return -ECONNRESET;
 }

 /* send STATUS stage. Should be called only for SET_CONFIGURATION */
 if (priv_dev->ep0_stage == CDNS3_STATUS_STAGE) {
  u32 val;

  cdns3_select_ep(priv_dev, 0x00);

  /*
 * Configure all non-control EPs which are not enabled by class driver
 */
  for (i = 0; i < CDNS3_ENDPOINTS_MAX_COUNT; i++) {
   priv_ep = priv_dev->eps[i];
   if (priv_ep && priv_ep->flags & EP_CLAIMED &&
       !(priv_ep->flags & EP_ENABLED))
    cdns3_ep_config(priv_ep, 0);
  }

  cdns3_set_hw_configuration(priv_dev);
  cdns3_ep0_complete_setup(priv_dev, 0, 1);
  /* wait until configuration set */
  ret = readl_poll_timeout_atomic(&priv_dev->regs->usb_sts, val,
       val & USB_STS_CFGSTS_MASK, 1, 100);
  if (ret == -ETIMEDOUT)
   dev_warn(priv_dev->dev, "timeout for waiting configuration set\n");

  request->actual = 0;
  priv_dev->status_completion_no_call = true;
  priv_dev->pending_status_request = request;
  usb_gadget_set_state(&priv_dev->gadget, USB_STATE_CONFIGURED);
  spin_unlock_irqrestore(&priv_dev->lock, flags);

  /*
 * Since there is no completion interrupt for status stage,
 * it needs to call ->completion in software after
 * ep0_queue is back.
 */
  queue_work(system_freezable_wq, &priv_dev->pending_status_wq);
  return ret;
 }

 if (!list_empty(&priv_ep->pending_req_list)) {
  dev_err(priv_dev->dev,
   "can't handle multiple requests for ep0\n");
  spin_unlock_irqrestore(&priv_dev->lock, flags);
  return -EBUSY;
 }

 ret = usb_gadget_map_request_by_dev(priv_dev->sysdev, request,
         priv_dev->ep0_data_dir);
 if (ret) {
  spin_unlock_irqrestore(&priv_dev->lock, flags);
  dev_err(priv_dev->dev, "failed to map request\n");
  return -EINVAL;
 }

 request->status = -EINPROGRESS;
 list_add_tail(&request->list, &priv_ep->pending_req_list);

 if (request->zero && request->length &&
     (request->length % ep->maxpacket == 0))
  zlp = 1;

 cdns3_ep0_run_transfer(priv_dev, request->dma, request->length, 1, zlp);

 spin_unlock_irqrestore(&priv_dev->lock, flags);

 return ret;
}

/**
 * cdns3_gadget_ep_set_wedge - Set wedge on selected endpoint
 * @ep: endpoint object
 *
 * Returns 0
 */
int cdns3_gadget_ep_set_wedge(struct usb_ep *ep)
{
 struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
 struct cdns3_device *priv_dev = priv_ep->cdns3_dev;

 dev_dbg(priv_dev->dev, "Wedge for %s\n", ep->name);
 cdns3_gadget_ep_set_halt(ep, 1);
 priv_ep->flags |= EP_WEDGE;

 return 0;
}

static const struct usb_ep_ops cdns3_gadget_ep0_ops = {
 .enable = cdns3_gadget_ep0_enable,
 .disable = cdns3_gadget_ep0_disable,
 .alloc_request = cdns3_gadget_ep_alloc_request,
 .free_request = cdns3_gadget_ep_free_request,
 .queue = cdns3_gadget_ep0_queue,
 .dequeue = cdns3_gadget_ep_dequeue,
 .set_halt = cdns3_gadget_ep0_set_halt,
 .set_wedge = cdns3_gadget_ep_set_wedge,
};

/**
 * cdns3_ep0_config - Configures default endpoint
 * @priv_dev: extended gadget object
 *
 * Functions sets parameters: maximal packet size and enables interrupts
 */
void cdns3_ep0_config(struct cdns3_device *priv_dev)
{
 struct cdns3_usb_regs __iomem *regs;
 struct cdns3_endpoint *priv_ep;
 u32 max_packet_size = 64;
 u32 ep_cfg;

 regs = priv_dev->regs;

 if (priv_dev->gadget.speed == USB_SPEED_SUPER)
  max_packet_size = 512;

 priv_ep = priv_dev->eps[0];

 if (!list_empty(&priv_ep->pending_req_list)) {
  struct usb_request *request;

  request = cdns3_next_request(&priv_ep->pending_req_list);
  list_del_init(&request->list);
 }

 priv_dev->u1_allowed = 0;
 priv_dev->u2_allowed = 0;

 priv_dev->gadget.ep0->maxpacket = max_packet_size;
 cdns3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(max_packet_size);

 /* init ep out */
 cdns3_select_ep(priv_dev, USB_DIR_OUT);

 if (priv_dev->dev_ver >= DEV_VER_V3) {
  cdns3_set_register_bit(&priv_dev->regs->dtrans,
           BIT(0) | BIT(16));
  cdns3_set_register_bit(&priv_dev->regs->tdl_from_trb,
           BIT(0) | BIT(16));
 }

 ep_cfg = EP_CFG_ENABLE | EP_CFG_MAXPKTSIZE(max_packet_size);

 if (!(priv_ep->flags & EP_CONFIGURED))
  writel(ep_cfg, ®s->ep_cfg);

 writel(EP_STS_EN_SETUPEN | EP_STS_EN_DESCMISEN | EP_STS_EN_TRBERREN,
        ®s->ep_sts_en);

 /* init ep in */
 cdns3_select_ep(priv_dev, USB_DIR_IN);

 if (!(priv_ep->flags & EP_CONFIGURED))
  writel(ep_cfg, ®s->ep_cfg);

 priv_ep->flags |= EP_CONFIGURED;

 writel(EP_STS_EN_SETUPEN | EP_STS_EN_TRBERREN, ®s->ep_sts_en);

 cdns3_set_register_bit(®s->usb_conf, USB_CONF_U1DS | USB_CONF_U2DS);
}

/**
 * cdns3_init_ep0 - Initializes software endpoint 0 of gadget
 * @priv_dev: extended gadget object
 * @priv_ep: extended endpoint object
 *
 * Returns 0 on success else error code.
 */
int cdns3_init_ep0(struct cdns3_device *priv_dev,
     struct cdns3_endpoint *priv_ep)
{
 sprintf(priv_ep->name, "ep0");

 /* fill linux fields */
 priv_ep->endpoint.ops = &cdns3_gadget_ep0_ops;
 priv_ep->endpoint.maxburst = 1;
 usb_ep_set_maxpacket_limit(&priv_ep->endpoint,
       CDNS3_EP0_MAX_PACKET_LIMIT);
 priv_ep->endpoint.address = 0;
 priv_ep->endpoint.caps.type_control = 1;
 priv_ep->endpoint.caps.dir_in = 1;
 priv_ep->endpoint.caps.dir_out = 1;
 priv_ep->endpoint.name = priv_ep->name;
 priv_ep->endpoint.desc = &cdns3_gadget_ep0_desc;
 priv_dev->gadget.ep0 = &priv_ep->endpoint;
 priv_ep->type = USB_ENDPOINT_XFER_CONTROL;

 return cdns3_allocate_trb_pool(priv_ep);
}