usb: cdns3: Add Cadence USB3 DRD Driver

This patch introduce new Cadence USBSS DRD driver to Linux kernel.

The Cadence USBSS DRD Controller is a highly configurable IP Core which
can be instantiated as Dual-Role Device (DRD), Peripheral Only and
Host Only (XHCI)configurations.

The current driver has been validated with FPGA platform. We have
support for PCIe bus, which is used on FPGA prototyping.

The host side of USBSS-DRD controller is compliant with XHCI
specification, so it works with standard XHCI Linux driver.

Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

1 files changed, 888 insertions, 0 deletions

diff --git a/drivers/usb/cdns3/ep0.c b/drivers/usb/cdns3/ep0.c
new file mode 100644
index 000000000000..e94f55d4729c
--- /dev/null
+++ b/drivers/usb/cdns3/ep0.c
@@ -0,0 +1,888 @@
+// 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 "gadget.h"
+#include "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
+ */
+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 = TRB_BUFFER(dma_addr);
+	priv_ep->trb_pool[0].length = TRB_LEN(length);
+
+	if (zlp) {
+		priv_ep->trb_pool[0].control = TRB_CYCLE | TRB_TYPE(TRB_NORMAL);
+		priv_ep->trb_pool[1].buffer = TRB_BUFFER(dma_addr);
+		priv_ep->trb_pool[1].length = TRB_LEN(0);
+		priv_ep->trb_pool[1].control = TRB_CYCLE | TRB_IOC |
+		    TRB_TYPE(TRB_NORMAL);
+	} else {
+		priv_ep->trb_pool[0].control = 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, &regs->ep_sts);
+	writel(EP_TRADDR_TRADDR(priv_ep->trb_pool_dma), &regs->ep_traddr);
+	trace_cdns3_doorbell_ep0(priv_dev->ep0_data_dir ? "ep0in" : "ep0out",
+				 readl(&regs->ep_traddr));
+
+	/* TRB should be prepared before starting transfer. */
+	writel(EP_CMD_DRDY, &regs->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_allow_enable_l1(priv_dev, 1);
+}
+
+/**
+ * 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;
+	struct cdns3_endpoint *priv_ep;
+	u32 config = le16_to_cpu(ctrl_req->wValue);
+	int result = 0;
+	int i;
+
+	switch (device_state) {
+	case USB_STATE_ADDRESS:
+		/* Configure non-control EPs */
+		for (i = 0; i < CDNS3_ENDPOINTS_MAX_COUNT; i++) {
+			priv_ep = priv_dev->eps[i];
+			if (!priv_ep)
+				continue;
+
+			if (priv_ep->flags & EP_CLAIMED)
+				cdns3_ep_config(priv_ep);
+		}
+
+		result = cdns3_ep0_delegate_req(priv_dev, ctrl_req);
+
+		if (result)
+			return result;
+
+		if (config) {
+			cdns3_set_hw_configuration(priv_dev);
+		} else {
+			cdns3_hw_reset_eps_config(priv_dev);
+			usb_gadget_set_state(&priv_dev->gadget,
+					     USB_STATE_ADDRESS);
+		}
+		break;
+	case USB_STATE_CONFIGURED:
+		result = cdns3_ep0_delegate_req(priv_dev, ctrl_req);
+
+		if (!config && !result) {
+			cdns3_hw_reset_eps_config(priv_dev);
+			usb_gadget_set_state(&priv_dev->gadget,
+					     USB_STATE_ADDRESS);
+		}
+		break;
+	default:
+		result = -EINVAL;
+	}
+
+	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_req: 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)
+{
+	__le16 *response_pkt;
+	u16 usb_status = 0;
+	u32 recip;
+
+	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:
+		/* check if endpoint is stalled */
+		cdns3_select_ep(priv_dev, ctrl->wIndex);
+		if (EP_STS_STALL(readl(&priv_dev->regs->ep_sts)))
+			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;
+	u32 wIndex;
+	u16 tmode;
+
+	wValue = le16_to_cpu(ctrl->wValue);
+	wIndex = le16_to_cpu(ctrl->wIndex);
+	state = priv_dev->gadget.state;
+	speed = priv_dev->gadget.speed;
+
+	switch (ctrl->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;
+
+		switch (tmode >> 8) {
+		case TEST_J:
+		case TEST_K:
+		case TEST_SE0_NAK:
+		case TEST_PACKET:
+			cdns3_ep0_complete_setup(priv_dev, 0, 1);
+			/**
+			 *  Little delay to give the controller some time
+			 * for sending status stage.
+			 * This time should be less then 3ms.
+			 */
+			usleep_range(1000, 2000);
+			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 (!(ctrl->wIndex & ~USB_DIR_IN))
+		return 0;
+
+	index = cdns3_ep_addr_to_index(ctrl->wIndex);
+	priv_ep = priv_dev->eps[index];
+
+	cdns3_select_ep(priv_dev, 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_req: 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 (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 = 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, 0 | 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_allow_enable_l1(priv_dev, 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
+ * 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
+ * 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 erdy_sent = 0;
+	int ret = 0;
+	u8 zlp = 0;
+
+	trace_cdns3_ep0_queue(priv_dev, request);
+
+	/* cancel the request if controller receive new SETUP packet. */
+	if (cdns3_check_new_setup(priv_dev))
+		return -ECONNRESET;
+
+	/* send STATUS stage. Should be called only for SET_CONFIGURATION */
+	if (priv_dev->ep0_stage == CDNS3_STATUS_STAGE) {
+		spin_lock_irqsave(&priv_dev->lock, flags);
+		cdns3_select_ep(priv_dev, 0x00);
+
+		erdy_sent = !priv_dev->hw_configured_flag;
+		cdns3_set_hw_configuration(priv_dev);
+
+		if (!erdy_sent)
+			cdns3_ep0_complete_setup(priv_dev, 0, 1);
+
+		cdns3_allow_enable_l1(priv_dev, 1);
+
+		request->actual = 0;
+		priv_dev->status_completion_no_call = true;
+		priv_dev->pending_status_request = request;
+		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 0;
+	}
+
+	spin_lock_irqsave(&priv_dev->lock, flags);
+	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;
+}
+
+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;
+
+	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));
+	}
+
+	writel(EP_CFG_ENABLE | EP_CFG_MAXPKTSIZE(max_packet_size),
+	       &regs->ep_cfg);
+
+	writel(EP_STS_EN_SETUPEN | EP_STS_EN_DESCMISEN | EP_STS_EN_TRBERREN,
+	       &regs->ep_sts_en);
+
+	/* init ep in */
+	cdns3_select_ep(priv_dev, USB_DIR_IN);
+
+	writel(EP_CFG_ENABLE | EP_CFG_MAXPKTSIZE(max_packet_size),
+	       &regs->ep_cfg);
+
+	writel(EP_STS_EN_SETUPEN | EP_STS_EN_TRBERREN, &regs->ep_sts_en);
+
+	cdns3_set_register_bit(&regs->usb_conf, USB_CONF_U1DS | USB_CONF_U2DS);
+}
+
+/**
+ * cdns3_init_ep0 Initializes software endpoint 0 of gadget
+ * @priv_dev: extended gadget object
+ * @ep_priv: 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);
+}