ep0.c

/**
 * ep0.c - DesignWare USB3 DRD Controller Endpoint 0 Handling
 *
 * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
 * All rights reserved.
 *
 * Authors: Felipe Balbi <balbi@ti.com>,
 *	    Sebastian Andrzej Siewior <bigeasy@linutronix.de>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The names of the above-listed copyright holders may not be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * ALTERNATIVELY, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2, as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/list.h>
#include <linux/dma-mapping.h>

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

#include "core.h"
#include "gadget.h"
#include "io.h"

static void dwc3_ep0_inspect_setup(struct dwc3 *dwc,
		const struct dwc3_event_depevt *event);

static const char *dwc3_ep0_state_string(enum dwc3_ep0_state state)
{
	switch (state) {
	case EP0_UNCONNECTED:
		return "Unconnected";
	case EP0_IDLE:
		return "Idle";
	case EP0_IN_DATA_PHASE:
		return "IN Data Phase";
	case EP0_OUT_DATA_PHASE:
		return "OUT Data Phase";
	case EP0_IN_WAIT_GADGET:
		return "IN Wait Gadget";
	case EP0_OUT_WAIT_GADGET:
		return "OUT Wait Gadget";
	case EP0_IN_WAIT_NRDY:
		return "IN Wait NRDY";
	case EP0_OUT_WAIT_NRDY:
		return "OUT Wait NRDY";
	case EP0_IN_STATUS_PHASE:
		return "IN Status Phase";
	case EP0_OUT_STATUS_PHASE:
		return "OUT Status Phase";
	case EP0_STALL:
		return "Stall";
	default:
		return "UNKNOWN";
	}
}

static int dwc3_ep0_start_trans(struct dwc3 *dwc, u8 epnum, dma_addr_t buf_dma,
		u32 len)
{
	struct dwc3_gadget_ep_cmd_params params;
	struct dwc3_trb_hw		*trb_hw;
	struct dwc3_trb			trb;
	struct dwc3_ep			*dep;

	int				ret;

	dep = dwc->eps[epnum];

	trb_hw = dwc->ep0_trb;
	memset(&trb, 0, sizeof(trb));

	switch (dwc->ep0state) {
	case EP0_IDLE:
		trb.trbctl = DWC3_TRBCTL_CONTROL_SETUP;
		break;

	case EP0_IN_WAIT_NRDY:
	case EP0_OUT_WAIT_NRDY:
	case EP0_IN_STATUS_PHASE:
	case EP0_OUT_STATUS_PHASE:
		if (dwc->three_stage_setup)
			trb.trbctl = DWC3_TRBCTL_CONTROL_STATUS3;
		else
			trb.trbctl = DWC3_TRBCTL_CONTROL_STATUS2;

		if (dwc->ep0state == EP0_IN_WAIT_NRDY)
			dwc->ep0state = EP0_IN_STATUS_PHASE;
		else if (dwc->ep0state == EP0_OUT_WAIT_NRDY)
			dwc->ep0state = EP0_OUT_STATUS_PHASE;
		break;

	case EP0_IN_WAIT_GADGET:
		dwc->ep0state = EP0_IN_WAIT_NRDY;
		return 0;
		break;

	case EP0_OUT_WAIT_GADGET:
		dwc->ep0state = EP0_OUT_WAIT_NRDY;
		return 0;

		break;

	case EP0_IN_DATA_PHASE:
	case EP0_OUT_DATA_PHASE:
		trb.trbctl = DWC3_TRBCTL_CONTROL_DATA;
		break;

	default:
		dev_err(dwc->dev, "%s() can't in state %d\n", __func__,
				dwc->ep0state);
		return -EINVAL;
	}

	trb.bplh = buf_dma;
	trb.length = len;

	trb.hwo	= 1;
	trb.lst	= 1;
	trb.ioc	= 1;
	trb.isp_imi = 1;

	dwc3_trb_to_hw(&trb, trb_hw);

	memset(&params, 0, sizeof(params));
	params.param0.depstrtxfer.transfer_desc_addr_high =
		upper_32_bits(dwc->ep0_trb_addr);
	params.param1.depstrtxfer.transfer_desc_addr_low =
		lower_32_bits(dwc->ep0_trb_addr);

	ret = dwc3_send_gadget_ep_cmd(dwc, dep->number,
			DWC3_DEPCMD_STARTTRANSFER, &params);
	if (ret < 0) {
		dev_dbg(dwc->dev, "failed to send STARTTRANSFER command\n");
		return ret;
	}

	dep->res_trans_idx = dwc3_gadget_ep_get_transfer_index(dwc,
			dep->number);

	return 0;
}

static int __dwc3_gadget_ep0_queue(struct dwc3_ep *dep,
		struct dwc3_request *req)
{
	struct dwc3		*dwc = dep->dwc;
	int			ret;

	req->request.actual	= 0;
	req->request.status	= -EINPROGRESS;
	req->direction		= dep->direction;
	req->epnum		= dep->number;

	list_add_tail(&req->list, &dep->request_list);
	dwc3_map_buffer_to_dma(req);

	ret = dwc3_ep0_start_trans(dwc, dep->number, req->request.dma,
			req->request.length);
	if (ret < 0) {
		list_del(&req->list);
		dwc3_unmap_buffer_from_dma(req);
	}

	return ret;
}

int dwc3_gadget_ep0_queue(struct usb_ep *ep, struct usb_request *request,
		gfp_t gfp_flags)
{
	struct dwc3_request		*req = to_dwc3_request(request);
	struct dwc3_ep			*dep = to_dwc3_ep(ep);
	struct dwc3			*dwc = dep->dwc;

	unsigned long			flags;

	int				ret;

	switch (dwc->ep0state) {
	case EP0_IN_DATA_PHASE:
	case EP0_IN_WAIT_GADGET:
	case EP0_IN_WAIT_NRDY:
	case EP0_IN_STATUS_PHASE:
		dep = dwc->eps[1];
		break;

	case EP0_OUT_DATA_PHASE:
	case EP0_OUT_WAIT_GADGET:
	case EP0_OUT_WAIT_NRDY:
	case EP0_OUT_STATUS_PHASE:
		dep = dwc->eps[0];
		break;
	default:
		return -EINVAL;
	}

	spin_lock_irqsave(&dwc->lock, flags);
	if (!dep->desc) {
		dev_dbg(dwc->dev, "trying to queue request %p to disabled %s\n",
				request, dep->name);
		ret = -ESHUTDOWN;
		goto out;
	}

	/* we share one TRB for ep0/1 */
	if (!list_empty(&dwc->eps[0]->request_list) ||
			!list_empty(&dwc->eps[1]->request_list) ||
			dwc->ep0_status_pending) {
		ret = -EBUSY;
		goto out;
	}

	dev_vdbg(dwc->dev, "queueing request %p to %s length %d, state '%s'\n",
			request, dep->name, request->length,
			dwc3_ep0_state_string(dwc->ep0state));

	ret = __dwc3_gadget_ep0_queue(dep, req);

out:
	spin_unlock_irqrestore(&dwc->lock, flags);

	return ret;
}

static void dwc3_ep0_stall_and_restart(struct dwc3 *dwc)
{
	/* stall is always issued on EP0 */
	__dwc3_gadget_ep_set_halt(dwc->eps[0], 1);
	dwc->eps[0]->flags &= ~DWC3_EP_STALL;
	dwc->ep0state = EP0_IDLE;
	dwc3_ep0_out_start(dwc);
}

void dwc3_ep0_out_start(struct dwc3 *dwc)
{
	struct dwc3_ep			*dep;
	int				ret;

	dep = dwc->eps[0];

	ret = dwc3_ep0_start_trans(dwc, 0, dwc->ctrl_req_addr, 8);
	WARN_ON(ret < 0);
}

/*
 * Send a zero length packet for the status phase of the control transfer
 */
static void dwc3_ep0_do_setup_status(struct dwc3 *dwc,
		const struct dwc3_event_depevt *event)
{
	struct dwc3_ep			*dep;
	int				ret;
	u32				epnum;

	epnum = event->endpoint_number;
	dep = dwc->eps[epnum];

	if (epnum)
		dwc->ep0state = EP0_IN_STATUS_PHASE;
	else
		dwc->ep0state = EP0_OUT_STATUS_PHASE;

	/*
	 * Not sure Why I need a buffer for a zero transfer. Maybe the
	 * HW reacts strange on a NULL pointer
	 */
	ret = dwc3_ep0_start_trans(dwc, epnum, dwc->ctrl_req_addr, 0);
	if (ret) {
		dev_dbg(dwc->dev, "failed to start transfer, stalling\n");
		dwc3_ep0_stall_and_restart(dwc);
	}
}

static struct dwc3_ep *dwc3_wIndex_to_dep(struct dwc3 *dwc, __le16 wIndex_le)
{
	struct dwc3_ep		*dep;
	u32			windex = le16_to_cpu(wIndex_le);
	u32			epnum;

	epnum = (windex & USB_ENDPOINT_NUMBER_MASK) << 1;
	if ((windex & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN)
		epnum |= 1;

	dep = dwc->eps[epnum];
	if (dep->flags & DWC3_EP_ENABLED)
		return dep;

	return NULL;
}

static void dwc3_ep0_send_status_response(struct dwc3 *dwc)
{
	u32 epnum;

	if (dwc->ep0state == EP0_IN_DATA_PHASE)
		epnum = 1;
	else
		epnum = 0;

	dwc3_ep0_start_trans(dwc, epnum, dwc->ctrl_req_addr,
			dwc->ep0_usb_req.length);
	dwc->ep0_status_pending = 1;
}

/*
 * ch 9.4.5
 */
static int dwc3_ep0_handle_status(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
{
	struct dwc3_ep		*dep;
	u32			recip;
	u16			usb_status = 0;
	__le16			*response_pkt;

	recip = ctrl->bRequestType & USB_RECIP_MASK;
	switch (recip) {
	case USB_RECIP_DEVICE:
		/*
		 * We are self-powered. U1/U2/LTM will be set later
		 * once we handle this states. RemoteWakeup is 0 on SS
		 */
		usb_status |= dwc->is_selfpowered << USB_DEVICE_SELF_POWERED;
		break;

	case USB_RECIP_INTERFACE:
		/*
		 * Function Remote Wake Capable	D0
		 * Function Remote Wakeup	D1
		 */
		break;

	case USB_RECIP_ENDPOINT:
		dep = dwc3_wIndex_to_dep(dwc, ctrl->wIndex);
		if (!dep)
		       return -EINVAL;

		if (dep->flags & DWC3_EP_STALL)
			usb_status = 1 << USB_ENDPOINT_HALT;
		break;
	default:
		return -EINVAL;
	};

	response_pkt = (__le16 *) dwc->setup_buf;
	*response_pkt = cpu_to_le16(usb_status);
	dwc->ep0_usb_req.length = sizeof(*response_pkt);
	dwc3_ep0_send_status_response(dwc);

	return 0;
}

static int dwc3_ep0_handle_feature(struct dwc3 *dwc,
		struct usb_ctrlrequest *ctrl, int set)
{
	struct dwc3_ep		*dep;
	u32			recip;
	u32			wValue;
	u32			wIndex;
	u32			reg;
	int			ret;
	u32			mode;

	wValue = le16_to_cpu(ctrl->wValue);
	wIndex = le16_to_cpu(ctrl->wIndex);
	recip = ctrl->bRequestType & USB_RECIP_MASK;
	switch (recip) {
	case USB_RECIP_DEVICE:

		/*
		 * 9.4.1 says only only for SS, in AddressState only for
		 * default control pipe
		 */
		switch (wValue) {
		case USB_DEVICE_U1_ENABLE:
		case USB_DEVICE_U2_ENABLE:
		case USB_DEVICE_LTM_ENABLE:
			if (dwc->dev_state != DWC3_CONFIGURED_STATE)
				return -EINVAL;
			if (dwc->speed != DWC3_DSTS_SUPERSPEED)
				return -EINVAL;
		}

		/* XXX add U[12] & LTM */
		switch (wValue) {
		case USB_DEVICE_REMOTE_WAKEUP:
			break;
		case USB_DEVICE_U1_ENABLE:
			break;
		case USB_DEVICE_U2_ENABLE:
			break;
		case USB_DEVICE_LTM_ENABLE:
			break;

		case USB_DEVICE_TEST_MODE:
			if ((wIndex & 0xff) != 0)
				return -EINVAL;
			if (!set)
				return -EINVAL;

			mode = wIndex >> 8;
			reg = dwc3_readl(dwc->regs, DWC3_DCTL);
			reg &= ~DWC3_DCTL_TSTCTRL_MASK;

			switch (mode) {
			case TEST_J:
			case TEST_K:
			case TEST_SE0_NAK:
			case TEST_PACKET:
			case TEST_FORCE_EN:
				reg |= mode << 1;
				break;
			default:
				return -EINVAL;
			}
			dwc3_writel(dwc->regs, DWC3_DCTL, reg);
			break;
		default:
			return -EINVAL;
		}
		break;

	case USB_RECIP_INTERFACE:
		switch (wValue) {
		case USB_INTRF_FUNC_SUSPEND:
			if (wIndex & USB_INTRF_FUNC_SUSPEND_LP)
				/* XXX enable Low power suspend */
				;
			if (wIndex & USB_INTRF_FUNC_SUSPEND_RW)
				/* XXX enable remote wakeup */
				;
			break;
		default:
			return -EINVAL;
		}
		break;

	case USB_RECIP_ENDPOINT:
		switch (wValue) {
		case USB_ENDPOINT_HALT:

			dep =  dwc3_wIndex_to_dep(dwc, ctrl->wIndex);
			if (!dep)
				return -EINVAL;
			ret = __dwc3_gadget_ep_set_halt(dep, set);
			if (ret)
				return -EINVAL;
			break;
		default:
			return -EINVAL;
		}
		break;

	default:
		return -EINVAL;
	};

	dwc->ep0state = EP0_IN_WAIT_NRDY;

	return 0;
}

static int dwc3_ep0_set_address(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
{
	int ret = 0;
	u32 addr;
	u32 reg;

	addr = le16_to_cpu(ctrl->wValue);
	if (addr > 127)
		return -EINVAL;

	switch (dwc->dev_state) {
	case DWC3_DEFAULT_STATE:
	case DWC3_ADDRESS_STATE:
		/*
		 * Not sure if we should program DevAddr now or later
		 */
		reg = dwc3_readl(dwc->regs, DWC3_DCFG);
		reg &= ~(DWC3_DCFG_DEVADDR_MASK);
		reg |= DWC3_DCFG_DEVADDR(addr);
		dwc3_writel(dwc->regs, DWC3_DCFG, reg);

		if (addr)
			dwc->dev_state = DWC3_ADDRESS_STATE;
		else
			dwc->dev_state = DWC3_DEFAULT_STATE;
		break;

	case DWC3_CONFIGURED_STATE:
		ret = -EINVAL;
		break;
	}
	dwc->ep0state = EP0_IN_WAIT_NRDY;
	return ret;
}

static int dwc3_ep0_delegate_req(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
{
	int ret;

	spin_unlock(&dwc->lock);
	ret = dwc->gadget_driver->setup(&dwc->gadget, ctrl);
	spin_lock(&dwc->lock);
	return ret;
}

static int dwc3_ep0_set_config(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
{
	u32 cfg;
	int ret;

	cfg = le16_to_cpu(ctrl->wValue);

	switch (dwc->dev_state) {
	case DWC3_DEFAULT_STATE:
		return -EINVAL;
		break;

	case DWC3_ADDRESS_STATE:
		ret = dwc3_ep0_delegate_req(dwc, ctrl);
		/* if the cfg matches and the cfg is non zero */
		if (!ret && cfg)
			dwc->dev_state = DWC3_CONFIGURED_STATE;
		break;

	case DWC3_CONFIGURED_STATE:
		ret = dwc3_ep0_delegate_req(dwc, ctrl);
		if (!cfg)
			dwc->dev_state = DWC3_ADDRESS_STATE;
		break;
	}
	return 0;
}

static int dwc3_ep0_std_request(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
{
	int ret;

	switch (ctrl->bRequest) {
	case USB_REQ_GET_STATUS:
		dev_vdbg(dwc->dev, "USB_REQ_GET_STATUS\n");
		ret = dwc3_ep0_handle_status(dwc, ctrl);
		break;
	case USB_REQ_CLEAR_FEATURE:
		dev_vdbg(dwc->dev, "USB_REQ_CLEAR_FEATURE\n");
		ret = dwc3_ep0_handle_feature(dwc, ctrl, 0);
		break;
	case USB_REQ_SET_FEATURE:
		dev_vdbg(dwc->dev, "USB_REQ_SET_FEATURE\n");
		ret = dwc3_ep0_handle_feature(dwc, ctrl, 1);
		break;
	case USB_REQ_SET_ADDRESS:
		dev_vdbg(dwc->dev, "USB_REQ_SET_ADDRESS\n");
		ret = dwc3_ep0_set_address(dwc, ctrl);
		break;
	case USB_REQ_SET_CONFIGURATION:
		dev_vdbg(dwc->dev, "USB_REQ_SET_CONFIGURATION\n");
		ret = dwc3_ep0_set_config(dwc, ctrl);
		break;
	default:
		dev_vdbg(dwc->dev, "Forwarding to gadget driver\n");
		ret = dwc3_ep0_delegate_req(dwc, ctrl);
		break;
	};

	return ret;
}

static void dwc3_ep0_inspect_setup(struct dwc3 *dwc,
		const struct dwc3_event_depevt *event)
{
	struct usb_ctrlrequest *ctrl = dwc->ctrl_req;
	int ret;
	u32 len;

	if (!dwc->gadget_driver)
		goto err;

	len = le16_to_cpu(ctrl->wLength);
	if (!len) {
		dwc->ep0state = EP0_IN_WAIT_GADGET;
		dwc->three_stage_setup = 0;
	} else {
		dwc->three_stage_setup = 1;
		if (ctrl->bRequestType & USB_DIR_IN)
			dwc->ep0state = EP0_IN_DATA_PHASE;
		else
			dwc->ep0state = EP0_OUT_DATA_PHASE;
	}

	if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
		ret = dwc3_ep0_std_request(dwc, ctrl);
	else
		ret = dwc3_ep0_delegate_req(dwc, ctrl);

	if (ret >= 0)
		return;

err:
	dwc3_ep0_stall_and_restart(dwc);
}

static void dwc3_ep0_complete_data(struct dwc3 *dwc,
		const struct dwc3_event_depevt *event)
{
	struct dwc3_request	*r = NULL;
	struct usb_request	*ur;
	struct dwc3_trb		trb;
	struct dwc3_ep		*dep;
	u32			transfered;
	u8			epnum;

	epnum = event->endpoint_number;
	dep = dwc->eps[epnum];

	if (!dwc->ep0_status_pending) {
		r = next_request(&dep->request_list);
		ur = &r->request;
	} else {
		ur = &dwc->ep0_usb_req;
		dwc->ep0_status_pending = 0;
	}

	dwc3_trb_to_nat(dwc->ep0_trb, &trb);

	transfered = ur->length - trb.length;
	ur->actual += transfered;

	if ((epnum & 1) && ur->actual < ur->length) {
		/* for some reason we did not get everything out */

		dwc3_ep0_stall_and_restart(dwc);
		dwc3_gadget_giveback(dep, r, -ECONNRESET);
	} else {
		/*
		 * handle the case where we have to send a zero packet. This
		 * seems to be case when req.length > maxpacket. Could it be?
		 */
		/* The transfer is complete, wait for HOST */
		if (epnum & 1)
			dwc->ep0state = EP0_IN_WAIT_NRDY;
		else
			dwc->ep0state = EP0_OUT_WAIT_NRDY;

		if (r)
			dwc3_gadget_giveback(dep, r, 0);
	}
}

static void dwc3_ep0_complete_req(struct dwc3 *dwc,
		const struct dwc3_event_depevt *event)
{
	struct dwc3_request	*r;
	struct dwc3_ep		*dep;
	u8			epnum;

	epnum = event->endpoint_number;
	dep = dwc->eps[epnum];

	if (!list_empty(&dep->request_list)) {
		r = next_request(&dep->request_list);

		dwc3_gadget_giveback(dep, r, 0);
	}

	dwc->ep0state = EP0_IDLE;
	dwc3_ep0_out_start(dwc);
}

static void dwc3_ep0_xfer_complete(struct dwc3 *dwc,
			const struct dwc3_event_depevt *event)
{
	switch (dwc->ep0state) {
	case EP0_IDLE:
		dwc3_ep0_inspect_setup(dwc, event);
		break;

	case EP0_IN_DATA_PHASE:
	case EP0_OUT_DATA_PHASE:
		dwc3_ep0_complete_data(dwc, event);
		break;

	case EP0_IN_STATUS_PHASE:
	case EP0_OUT_STATUS_PHASE:
		dwc3_ep0_complete_req(dwc, event);
		break;

	case EP0_IN_WAIT_NRDY:
	case EP0_OUT_WAIT_NRDY:
	case EP0_IN_WAIT_GADGET:
	case EP0_OUT_WAIT_GADGET:
	case EP0_UNCONNECTED:
	case EP0_STALL:
		break;
	}
}

static void dwc3_ep0_xfernotready(struct dwc3 *dwc,
		const struct dwc3_event_depevt *event)
{
	switch (dwc->ep0state) {
	case EP0_IN_WAIT_GADGET:
		dwc->ep0state = EP0_IN_WAIT_NRDY;
		break;
	case EP0_OUT_WAIT_GADGET:
		dwc->ep0state = EP0_OUT_WAIT_NRDY;
		break;

	case EP0_IN_WAIT_NRDY:
	case EP0_OUT_WAIT_NRDY:
		dwc3_ep0_do_setup_status(dwc, event);
		break;

	case EP0_IDLE:
	case EP0_IN_STATUS_PHASE:
	case EP0_OUT_STATUS_PHASE:
	case EP0_IN_DATA_PHASE:
	case EP0_OUT_DATA_PHASE:
	case EP0_UNCONNECTED:
	case EP0_STALL:
		break;
	}
}

void dwc3_ep0_interrupt(struct dwc3 *dwc,
		const const struct dwc3_event_depevt *event)
{
	u8			epnum = event->endpoint_number;

	dev_dbg(dwc->dev, "%s while ep%d%s in state '%s'\n",
			dwc3_ep_event_string(event->endpoint_event),
			epnum, (epnum & 1) ? "in" : "out",
			dwc3_ep0_state_string(dwc->ep0state));

	switch (event->endpoint_event) {
	case DWC3_DEPEVT_XFERCOMPLETE:
		dwc3_ep0_xfer_complete(dwc, event);
		break;

	case DWC3_DEPEVT_XFERNOTREADY:
		dwc3_ep0_xfernotready(dwc, event);
		break;

	case DWC3_DEPEVT_XFERINPROGRESS:
	case DWC3_DEPEVT_RXTXFIFOEVT:
	case DWC3_DEPEVT_STREAMEVT:
	case DWC3_DEPEVT_EPCMDCMPLT:
		break;
	}
}