Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 895 insertions, 0 deletions

diff --git a/drivers/usb/cdns3/cdns3-ep0.c b/drivers/usb/cdns3/cdns3-ep0.c
new file mode 100644
index 0000000000..e29989d57b
--- /dev/null
+++ b/drivers/usb/cdns3/cdns3-ep0.c
@@ -0,0 +1,895 @@
+// 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, &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_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, &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);
+
+	if (!(priv_ep->flags & EP_CONFIGURED))
+		writel(ep_cfg, &regs->ep_cfg);
+
+	priv_ep->flags |= EP_CONFIGURED;
+
+	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
+ * @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);
+}