Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 4748 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
new file mode 100644
index 0000000000..89de363ecf
--- /dev/null
+++ b/drivers/usb/dwc3/gadget.c
@@ -0,0 +1,4748 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * gadget.c - DesignWare USB3 DRD Controller Gadget Framework Link
+ *
+ * Copyright (C) 2010-2011 Texas Instruments Incorporated - https://www.ti.com
+ *
+ * Authors: Felipe Balbi <balbi@ti.com>,
+ *	    Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+ */
+
+#include <linux/kernel.h>
+#include <linux/delay.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 "debug.h"
+#include "core.h"
+#include "gadget.h"
+#include "io.h"
+
+#define DWC3_ALIGN_FRAME(d, n)	(((d)->frame_number + ((d)->interval * (n))) \
+					& ~((d)->interval - 1))
+
+/**
+ * dwc3_gadget_set_test_mode - enables usb2 test modes
+ * @dwc: pointer to our context structure
+ * @mode: the mode to set (J, K SE0 NAK, Force Enable)
+ *
+ * Caller should take care of locking. This function will return 0 on
+ * success or -EINVAL if wrong Test Selector is passed.
+ */
+int dwc3_gadget_set_test_mode(struct dwc3 *dwc, int mode)
+{
+	u32		reg;
+
+	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+	reg &= ~DWC3_DCTL_TSTCTRL_MASK;
+
+	switch (mode) {
+	case USB_TEST_J:
+	case USB_TEST_K:
+	case USB_TEST_SE0_NAK:
+	case USB_TEST_PACKET:
+	case USB_TEST_FORCE_ENABLE:
+		reg |= mode << 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	dwc3_gadget_dctl_write_safe(dwc, reg);
+
+	return 0;
+}
+
+/**
+ * dwc3_gadget_get_link_state - gets current state of usb link
+ * @dwc: pointer to our context structure
+ *
+ * Caller should take care of locking. This function will
+ * return the link state on success (>= 0) or -ETIMEDOUT.
+ */
+int dwc3_gadget_get_link_state(struct dwc3 *dwc)
+{
+	u32		reg;
+
+	reg = dwc3_readl(dwc->regs, DWC3_DSTS);
+
+	return DWC3_DSTS_USBLNKST(reg);
+}
+
+/**
+ * dwc3_gadget_set_link_state - sets usb link to a particular state
+ * @dwc: pointer to our context structure
+ * @state: the state to put link into
+ *
+ * Caller should take care of locking. This function will
+ * return 0 on success or -ETIMEDOUT.
+ */
+int dwc3_gadget_set_link_state(struct dwc3 *dwc, enum dwc3_link_state state)
+{
+	int		retries = 10000;
+	u32		reg;
+
+	/*
+	 * Wait until device controller is ready. Only applies to 1.94a and
+	 * later RTL.
+	 */
+	if (!DWC3_VER_IS_PRIOR(DWC3, 194A)) {
+		while (--retries) {
+			reg = dwc3_readl(dwc->regs, DWC3_DSTS);
+			if (reg & DWC3_DSTS_DCNRD)
+				udelay(5);
+			else
+				break;
+		}
+
+		if (retries <= 0)
+			return -ETIMEDOUT;
+	}
+
+	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+	reg &= ~DWC3_DCTL_ULSTCHNGREQ_MASK;
+
+	/* set no action before sending new link state change */
+	dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+
+	/* set requested state */
+	reg |= DWC3_DCTL_ULSTCHNGREQ(state);
+	dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+
+	/*
+	 * The following code is racy when called from dwc3_gadget_wakeup,
+	 * and is not needed, at least on newer versions
+	 */
+	if (!DWC3_VER_IS_PRIOR(DWC3, 194A))
+		return 0;
+
+	/* wait for a change in DSTS */
+	retries = 10000;
+	while (--retries) {
+		reg = dwc3_readl(dwc->regs, DWC3_DSTS);
+
+		if (DWC3_DSTS_USBLNKST(reg) == state)
+			return 0;
+
+		udelay(5);
+	}
+
+	return -ETIMEDOUT;
+}
+
+static void dwc3_ep0_reset_state(struct dwc3 *dwc)
+{
+	unsigned int	dir;
+
+	if (dwc->ep0state != EP0_SETUP_PHASE) {
+		dir = !!dwc->ep0_expect_in;
+		if (dwc->ep0state == EP0_DATA_PHASE)
+			dwc3_ep0_end_control_data(dwc, dwc->eps[dir]);
+		else
+			dwc3_ep0_end_control_data(dwc, dwc->eps[!dir]);
+
+		dwc->eps[0]->trb_enqueue = 0;
+		dwc->eps[1]->trb_enqueue = 0;
+
+		dwc3_ep0_stall_and_restart(dwc);
+	}
+}
+
+/**
+ * dwc3_ep_inc_trb - increment a trb index.
+ * @index: Pointer to the TRB index to increment.
+ *
+ * The index should never point to the link TRB. After incrementing,
+ * if it is point to the link TRB, wrap around to the beginning. The
+ * link TRB is always at the last TRB entry.
+ */
+static void dwc3_ep_inc_trb(u8 *index)
+{
+	(*index)++;
+	if (*index == (DWC3_TRB_NUM - 1))
+		*index = 0;
+}
+
+/**
+ * dwc3_ep_inc_enq - increment endpoint's enqueue pointer
+ * @dep: The endpoint whose enqueue pointer we're incrementing
+ */
+static void dwc3_ep_inc_enq(struct dwc3_ep *dep)
+{
+	dwc3_ep_inc_trb(&dep->trb_enqueue);
+}
+
+/**
+ * dwc3_ep_inc_deq - increment endpoint's dequeue pointer
+ * @dep: The endpoint whose enqueue pointer we're incrementing
+ */
+static void dwc3_ep_inc_deq(struct dwc3_ep *dep)
+{
+	dwc3_ep_inc_trb(&dep->trb_dequeue);
+}
+
+static void dwc3_gadget_del_and_unmap_request(struct dwc3_ep *dep,
+		struct dwc3_request *req, int status)
+{
+	struct dwc3			*dwc = dep->dwc;
+
+	list_del(&req->list);
+	req->remaining = 0;
+	req->needs_extra_trb = false;
+	req->num_trbs = 0;
+
+	if (req->request.status == -EINPROGRESS)
+		req->request.status = status;
+
+	if (req->trb)
+		usb_gadget_unmap_request_by_dev(dwc->sysdev,
+				&req->request, req->direction);
+
+	req->trb = NULL;
+	trace_dwc3_gadget_giveback(req);
+
+	if (dep->number > 1)
+		pm_runtime_put(dwc->dev);
+}
+
+/**
+ * dwc3_gadget_giveback - call struct usb_request's ->complete callback
+ * @dep: The endpoint to whom the request belongs to
+ * @req: The request we're giving back
+ * @status: completion code for the request
+ *
+ * Must be called with controller's lock held and interrupts disabled. This
+ * function will unmap @req and call its ->complete() callback to notify upper
+ * layers that it has completed.
+ */
+void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
+		int status)
+{
+	struct dwc3			*dwc = dep->dwc;
+
+	dwc3_gadget_del_and_unmap_request(dep, req, status);
+	req->status = DWC3_REQUEST_STATUS_COMPLETED;
+
+	spin_unlock(&dwc->lock);
+	usb_gadget_giveback_request(&dep->endpoint, &req->request);
+	spin_lock(&dwc->lock);
+}
+
+/**
+ * dwc3_send_gadget_generic_command - issue a generic command for the controller
+ * @dwc: pointer to the controller context
+ * @cmd: the command to be issued
+ * @param: command parameter
+ *
+ * Caller should take care of locking. Issue @cmd with a given @param to @dwc
+ * and wait for its completion.
+ */
+int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned int cmd,
+		u32 param)
+{
+	u32		timeout = 500;
+	int		status = 0;
+	int		ret = 0;
+	u32		reg;
+
+	dwc3_writel(dwc->regs, DWC3_DGCMDPAR, param);
+	dwc3_writel(dwc->regs, DWC3_DGCMD, cmd | DWC3_DGCMD_CMDACT);
+
+	do {
+		reg = dwc3_readl(dwc->regs, DWC3_DGCMD);
+		if (!(reg & DWC3_DGCMD_CMDACT)) {
+			status = DWC3_DGCMD_STATUS(reg);
+			if (status)
+				ret = -EINVAL;
+			break;
+		}
+	} while (--timeout);
+
+	if (!timeout) {
+		ret = -ETIMEDOUT;
+		status = -ETIMEDOUT;
+	}
+
+	trace_dwc3_gadget_generic_cmd(cmd, param, status);
+
+	return ret;
+}
+
+static int __dwc3_gadget_wakeup(struct dwc3 *dwc, bool async);
+
+/**
+ * dwc3_send_gadget_ep_cmd - issue an endpoint command
+ * @dep: the endpoint to which the command is going to be issued
+ * @cmd: the command to be issued
+ * @params: parameters to the command
+ *
+ * Caller should handle locking. This function will issue @cmd with given
+ * @params to @dep and wait for its completion.
+ */
+int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned int cmd,
+		struct dwc3_gadget_ep_cmd_params *params)
+{
+	const struct usb_endpoint_descriptor *desc = dep->endpoint.desc;
+	struct dwc3		*dwc = dep->dwc;
+	u32			timeout = 5000;
+	u32			saved_config = 0;
+	u32			reg;
+
+	int			cmd_status = 0;
+	int			ret = -EINVAL;
+
+	/*
+	 * When operating in USB 2.0 speeds (HS/FS), if GUSB2PHYCFG.ENBLSLPM or
+	 * GUSB2PHYCFG.SUSPHY is set, it must be cleared before issuing an
+	 * endpoint command.
+	 *
+	 * Save and clear both GUSB2PHYCFG.ENBLSLPM and GUSB2PHYCFG.SUSPHY
+	 * settings. Restore them after the command is completed.
+	 *
+	 * DWC_usb3 3.30a and DWC_usb31 1.90a programming guide section 3.2.2
+	 */
+	if (dwc->gadget->speed <= USB_SPEED_HIGH ||
+	    DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_ENDTRANSFER) {
+		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
+		if (unlikely(reg & DWC3_GUSB2PHYCFG_SUSPHY)) {
+			saved_config |= DWC3_GUSB2PHYCFG_SUSPHY;
+			reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
+		}
+
+		if (reg & DWC3_GUSB2PHYCFG_ENBLSLPM) {
+			saved_config |= DWC3_GUSB2PHYCFG_ENBLSLPM;
+			reg &= ~DWC3_GUSB2PHYCFG_ENBLSLPM;
+		}
+
+		if (saved_config)
+			dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
+	}
+
+	if (DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_STARTTRANSFER) {
+		int link_state;
+
+		/*
+		 * Initiate remote wakeup if the link state is in U3 when
+		 * operating in SS/SSP or L1/L2 when operating in HS/FS. If the
+		 * link state is in U1/U2, no remote wakeup is needed. The Start
+		 * Transfer command will initiate the link recovery.
+		 */
+		link_state = dwc3_gadget_get_link_state(dwc);
+		switch (link_state) {
+		case DWC3_LINK_STATE_U2:
+			if (dwc->gadget->speed >= USB_SPEED_SUPER)
+				break;
+
+			fallthrough;
+		case DWC3_LINK_STATE_U3:
+			ret = __dwc3_gadget_wakeup(dwc, false);
+			dev_WARN_ONCE(dwc->dev, ret, "wakeup failed --> %d\n",
+					ret);
+			break;
+		}
+	}
+
+	/*
+	 * For some commands such as Update Transfer command, DEPCMDPARn
+	 * registers are reserved. Since the driver often sends Update Transfer
+	 * command, don't write to DEPCMDPARn to avoid register write delays and
+	 * improve performance.
+	 */
+	if (DWC3_DEPCMD_CMD(cmd) != DWC3_DEPCMD_UPDATETRANSFER) {
+		dwc3_writel(dep->regs, DWC3_DEPCMDPAR0, params->param0);
+		dwc3_writel(dep->regs, DWC3_DEPCMDPAR1, params->param1);
+		dwc3_writel(dep->regs, DWC3_DEPCMDPAR2, params->param2);
+	}
+
+	/*
+	 * Synopsys Databook 2.60a states in section 6.3.2.5.6 of that if we're
+	 * not relying on XferNotReady, we can make use of a special "No
+	 * Response Update Transfer" command where we should clear both CmdAct
+	 * and CmdIOC bits.
+	 *
+	 * With this, we don't need to wait for command completion and can
+	 * straight away issue further commands to the endpoint.
+	 *
+	 * NOTICE: We're making an assumption that control endpoints will never
+	 * make use of Update Transfer command. This is a safe assumption
+	 * because we can never have more than one request at a time with
+	 * Control Endpoints. If anybody changes that assumption, this chunk
+	 * needs to be updated accordingly.
+	 */
+	if (DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_UPDATETRANSFER &&
+			!usb_endpoint_xfer_isoc(desc))
+		cmd &= ~(DWC3_DEPCMD_CMDIOC | DWC3_DEPCMD_CMDACT);
+	else
+		cmd |= DWC3_DEPCMD_CMDACT;
+
+	dwc3_writel(dep->regs, DWC3_DEPCMD, cmd);
+
+	if (!(cmd & DWC3_DEPCMD_CMDACT) ||
+		(DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_ENDTRANSFER &&
+		!(cmd & DWC3_DEPCMD_CMDIOC))) {
+		ret = 0;
+		goto skip_status;
+	}
+
+	do {
+		reg = dwc3_readl(dep->regs, DWC3_DEPCMD);
+		if (!(reg & DWC3_DEPCMD_CMDACT)) {
+			cmd_status = DWC3_DEPCMD_STATUS(reg);
+
+			switch (cmd_status) {
+			case 0:
+				ret = 0;
+				break;
+			case DEPEVT_TRANSFER_NO_RESOURCE:
+				dev_WARN(dwc->dev, "No resource for %s\n",
+					 dep->name);
+				ret = -EINVAL;
+				break;
+			case DEPEVT_TRANSFER_BUS_EXPIRY:
+				/*
+				 * SW issues START TRANSFER command to
+				 * isochronous ep with future frame interval. If
+				 * future interval time has already passed when
+				 * core receives the command, it will respond
+				 * with an error status of 'Bus Expiry'.
+				 *
+				 * Instead of always returning -EINVAL, let's
+				 * give a hint to the gadget driver that this is
+				 * the case by returning -EAGAIN.
+				 */
+				ret = -EAGAIN;
+				break;
+			default:
+				dev_WARN(dwc->dev, "UNKNOWN cmd status\n");
+			}
+
+			break;
+		}
+	} while (--timeout);
+
+	if (timeout == 0) {
+		ret = -ETIMEDOUT;
+		cmd_status = -ETIMEDOUT;
+	}
+
+skip_status:
+	trace_dwc3_gadget_ep_cmd(dep, cmd, params, cmd_status);
+
+	if (DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_STARTTRANSFER) {
+		if (ret == 0)
+			dep->flags |= DWC3_EP_TRANSFER_STARTED;
+
+		if (ret != -ETIMEDOUT)
+			dwc3_gadget_ep_get_transfer_index(dep);
+	}
+
+	if (saved_config) {
+		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
+		reg |= saved_config;
+		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
+	}
+
+	return ret;
+}
+
+static int dwc3_send_clear_stall_ep_cmd(struct dwc3_ep *dep)
+{
+	struct dwc3 *dwc = dep->dwc;
+	struct dwc3_gadget_ep_cmd_params params;
+	u32 cmd = DWC3_DEPCMD_CLEARSTALL;
+
+	/*
+	 * As of core revision 2.60a the recommended programming model
+	 * is to set the ClearPendIN bit when issuing a Clear Stall EP
+	 * command for IN endpoints. This is to prevent an issue where
+	 * some (non-compliant) hosts may not send ACK TPs for pending
+	 * IN transfers due to a mishandled error condition. Synopsys
+	 * STAR 9000614252.
+	 */
+	if (dep->direction &&
+	    !DWC3_VER_IS_PRIOR(DWC3, 260A) &&
+	    (dwc->gadget->speed >= USB_SPEED_SUPER))
+		cmd |= DWC3_DEPCMD_CLEARPENDIN;
+
+	memset(&params, 0, sizeof(params));
+
+	return dwc3_send_gadget_ep_cmd(dep, cmd, &params);
+}
+
+static dma_addr_t dwc3_trb_dma_offset(struct dwc3_ep *dep,
+		struct dwc3_trb *trb)
+{
+	u32		offset = (char *) trb - (char *) dep->trb_pool;
+
+	return dep->trb_pool_dma + offset;
+}
+
+static int dwc3_alloc_trb_pool(struct dwc3_ep *dep)
+{
+	struct dwc3		*dwc = dep->dwc;
+
+	if (dep->trb_pool)
+		return 0;
+
+	dep->trb_pool = dma_alloc_coherent(dwc->sysdev,
+			sizeof(struct dwc3_trb) * DWC3_TRB_NUM,
+			&dep->trb_pool_dma, GFP_KERNEL);
+	if (!dep->trb_pool) {
+		dev_err(dep->dwc->dev, "failed to allocate trb pool for %s\n",
+				dep->name);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void dwc3_free_trb_pool(struct dwc3_ep *dep)
+{
+	struct dwc3		*dwc = dep->dwc;
+
+	dma_free_coherent(dwc->sysdev, sizeof(struct dwc3_trb) * DWC3_TRB_NUM,
+			dep->trb_pool, dep->trb_pool_dma);
+
+	dep->trb_pool = NULL;
+	dep->trb_pool_dma = 0;
+}
+
+static int dwc3_gadget_set_xfer_resource(struct dwc3_ep *dep)
+{
+	struct dwc3_gadget_ep_cmd_params params;
+
+	memset(&params, 0x00, sizeof(params));
+
+	params.param0 = DWC3_DEPXFERCFG_NUM_XFER_RES(1);
+
+	return dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETTRANSFRESOURCE,
+			&params);
+}
+
+/**
+ * dwc3_gadget_start_config - configure ep resources
+ * @dep: endpoint that is being enabled
+ *
+ * Issue a %DWC3_DEPCMD_DEPSTARTCFG command to @dep. After the command's
+ * completion, it will set Transfer Resource for all available endpoints.
+ *
+ * The assignment of transfer resources cannot perfectly follow the data book
+ * due to the fact that the controller driver does not have all knowledge of the
+ * configuration in advance. It is given this information piecemeal by the
+ * composite gadget framework after every SET_CONFIGURATION and
+ * SET_INTERFACE. Trying to follow the databook programming model in this
+ * scenario can cause errors. For two reasons:
+ *
+ * 1) The databook says to do %DWC3_DEPCMD_DEPSTARTCFG for every
+ * %USB_REQ_SET_CONFIGURATION and %USB_REQ_SET_INTERFACE (8.1.5). This is
+ * incorrect in the scenario of multiple interfaces.
+ *
+ * 2) The databook does not mention doing more %DWC3_DEPCMD_DEPXFERCFG for new
+ * endpoint on alt setting (8.1.6).
+ *
+ * The following simplified method is used instead:
+ *
+ * All hardware endpoints can be assigned a transfer resource and this setting
+ * will stay persistent until either a core reset or hibernation. So whenever we
+ * do a %DWC3_DEPCMD_DEPSTARTCFG(0) we can go ahead and do
+ * %DWC3_DEPCMD_DEPXFERCFG for every hardware endpoint as well. We are
+ * guaranteed that there are as many transfer resources as endpoints.
+ *
+ * This function is called for each endpoint when it is being enabled but is
+ * triggered only when called for EP0-out, which always happens first, and which
+ * should only happen in one of the above conditions.
+ */
+static int dwc3_gadget_start_config(struct dwc3_ep *dep)
+{
+	struct dwc3_gadget_ep_cmd_params params;
+	struct dwc3		*dwc;
+	u32			cmd;
+	int			i;
+	int			ret;
+
+	if (dep->number)
+		return 0;
+
+	memset(&params, 0x00, sizeof(params));
+	cmd = DWC3_DEPCMD_DEPSTARTCFG;
+	dwc = dep->dwc;
+
+	ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < DWC3_ENDPOINTS_NUM; i++) {
+		struct dwc3_ep *dep = dwc->eps[i];
+
+		if (!dep)
+			continue;
+
+		ret = dwc3_gadget_set_xfer_resource(dep);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int dwc3_gadget_set_ep_config(struct dwc3_ep *dep, unsigned int action)
+{
+	const struct usb_ss_ep_comp_descriptor *comp_desc;
+	const struct usb_endpoint_descriptor *desc;
+	struct dwc3_gadget_ep_cmd_params params;
+	struct dwc3 *dwc = dep->dwc;
+
+	comp_desc = dep->endpoint.comp_desc;
+	desc = dep->endpoint.desc;
+
+	memset(&params, 0x00, sizeof(params));
+
+	params.param0 = DWC3_DEPCFG_EP_TYPE(usb_endpoint_type(desc))
+		| DWC3_DEPCFG_MAX_PACKET_SIZE(usb_endpoint_maxp(desc));
+
+	/* Burst size is only needed in SuperSpeed mode */
+	if (dwc->gadget->speed >= USB_SPEED_SUPER) {
+		u32 burst = dep->endpoint.maxburst;
+
+		params.param0 |= DWC3_DEPCFG_BURST_SIZE(burst - 1);
+	}
+
+	params.param0 |= action;
+	if (action == DWC3_DEPCFG_ACTION_RESTORE)
+		params.param2 |= dep->saved_state;
+
+	if (usb_endpoint_xfer_control(desc))
+		params.param1 = DWC3_DEPCFG_XFER_COMPLETE_EN;
+
+	if (dep->number <= 1 || usb_endpoint_xfer_isoc(desc))
+		params.param1 |= DWC3_DEPCFG_XFER_NOT_READY_EN;
+
+	if (usb_ss_max_streams(comp_desc) && usb_endpoint_xfer_bulk(desc)) {
+		params.param1 |= DWC3_DEPCFG_STREAM_CAPABLE
+			| DWC3_DEPCFG_XFER_COMPLETE_EN
+			| DWC3_DEPCFG_STREAM_EVENT_EN;
+		dep->stream_capable = true;
+	}
+
+	if (!usb_endpoint_xfer_control(desc))
+		params.param1 |= DWC3_DEPCFG_XFER_IN_PROGRESS_EN;
+
+	/*
+	 * We are doing 1:1 mapping for endpoints, meaning
+	 * Physical Endpoints 2 maps to Logical Endpoint 2 and
+	 * so on. We consider the direction bit as part of the physical
+	 * endpoint number. So USB endpoint 0x81 is 0x03.
+	 */
+	params.param1 |= DWC3_DEPCFG_EP_NUMBER(dep->number);
+
+	/*
+	 * We must use the lower 16 TX FIFOs even though
+	 * HW might have more
+	 */
+	if (dep->direction)
+		params.param0 |= DWC3_DEPCFG_FIFO_NUMBER(dep->number >> 1);
+
+	if (desc->bInterval) {
+		u8 bInterval_m1;
+
+		/*
+		 * Valid range for DEPCFG.bInterval_m1 is from 0 to 13.
+		 *
+		 * NOTE: The programming guide incorrectly stated bInterval_m1
+		 * must be set to 0 when operating in fullspeed. Internally the
+		 * controller does not have this limitation. See DWC_usb3x
+		 * programming guide section 3.2.2.1.
+		 */
+		bInterval_m1 = min_t(u8, desc->bInterval - 1, 13);
+
+		if (usb_endpoint_type(desc) == USB_ENDPOINT_XFER_INT &&
+		    dwc->gadget->speed == USB_SPEED_FULL)
+			dep->interval = desc->bInterval;
+		else
+			dep->interval = 1 << (desc->bInterval - 1);
+
+		params.param1 |= DWC3_DEPCFG_BINTERVAL_M1(bInterval_m1);
+	}
+
+	return dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETEPCONFIG, &params);
+}
+
+/**
+ * dwc3_gadget_calc_tx_fifo_size - calculates the txfifo size value
+ * @dwc: pointer to the DWC3 context
+ * @mult: multiplier to be used when calculating the fifo_size
+ *
+ * Calculates the size value based on the equation below:
+ *
+ * DWC3 revision 280A and prior:
+ * fifo_size = mult * (max_packet / mdwidth) + 1;
+ *
+ * DWC3 revision 290A and onwards:
+ * fifo_size = mult * ((max_packet + mdwidth)/mdwidth + 1) + 1
+ *
+ * The max packet size is set to 1024, as the txfifo requirements mainly apply
+ * to super speed USB use cases.  However, it is safe to overestimate the fifo
+ * allocations for other scenarios, i.e. high speed USB.
+ */
+static int dwc3_gadget_calc_tx_fifo_size(struct dwc3 *dwc, int mult)
+{
+	int max_packet = 1024;
+	int fifo_size;
+	int mdwidth;
+
+	mdwidth = dwc3_mdwidth(dwc);
+
+	/* MDWIDTH is represented in bits, we need it in bytes */
+	mdwidth >>= 3;
+
+	if (DWC3_VER_IS_PRIOR(DWC3, 290A))
+		fifo_size = mult * (max_packet / mdwidth) + 1;
+	else
+		fifo_size = mult * ((max_packet + mdwidth) / mdwidth) + 1;
+	return fifo_size;
+}
+
+/**
+ * dwc3_gadget_clear_tx_fifos - Clears txfifo allocation
+ * @dwc: pointer to the DWC3 context
+ *
+ * Iterates through all the endpoint registers and clears the previous txfifo
+ * allocations.
+ */
+void dwc3_gadget_clear_tx_fifos(struct dwc3 *dwc)
+{
+	struct dwc3_ep *dep;
+	int fifo_depth;
+	int size;
+	int num;
+
+	if (!dwc->do_fifo_resize)
+		return;
+
+	/* Read ep0IN related TXFIFO size */
+	dep = dwc->eps[1];
+	size = dwc3_readl(dwc->regs, DWC3_GTXFIFOSIZ(0));
+	if (DWC3_IP_IS(DWC3))
+		fifo_depth = DWC3_GTXFIFOSIZ_TXFDEP(size);
+	else
+		fifo_depth = DWC31_GTXFIFOSIZ_TXFDEP(size);
+
+	dwc->last_fifo_depth = fifo_depth;
+	/* Clear existing TXFIFO for all IN eps except ep0 */
+	for (num = 3; num < min_t(int, dwc->num_eps, DWC3_ENDPOINTS_NUM);
+	     num += 2) {
+		dep = dwc->eps[num];
+		/* Don't change TXFRAMNUM on usb31 version */
+		size = DWC3_IP_IS(DWC3) ? 0 :
+			dwc3_readl(dwc->regs, DWC3_GTXFIFOSIZ(num >> 1)) &
+				   DWC31_GTXFIFOSIZ_TXFRAMNUM;
+
+		dwc3_writel(dwc->regs, DWC3_GTXFIFOSIZ(num >> 1), size);
+		dep->flags &= ~DWC3_EP_TXFIFO_RESIZED;
+	}
+	dwc->num_ep_resized = 0;
+}
+
+/*
+ * dwc3_gadget_resize_tx_fifos - reallocate fifo spaces for current use-case
+ * @dwc: pointer to our context structure
+ *
+ * This function will a best effort FIFO allocation in order
+ * to improve FIFO usage and throughput, while still allowing
+ * us to enable as many endpoints as possible.
+ *
+ * Keep in mind that this operation will be highly dependent
+ * on the configured size for RAM1 - which contains TxFifo -,
+ * the amount of endpoints enabled on coreConsultant tool, and
+ * the width of the Master Bus.
+ *
+ * In general, FIFO depths are represented with the following equation:
+ *
+ * fifo_size = mult * ((max_packet + mdwidth)/mdwidth + 1) + 1
+ *
+ * In conjunction with dwc3_gadget_check_config(), this resizing logic will
+ * ensure that all endpoints will have enough internal memory for one max
+ * packet per endpoint.
+ */
+static int dwc3_gadget_resize_tx_fifos(struct dwc3_ep *dep)
+{
+	struct dwc3 *dwc = dep->dwc;
+	int fifo_0_start;
+	int ram1_depth;
+	int fifo_size;
+	int min_depth;
+	int num_in_ep;
+	int remaining;
+	int num_fifos = 1;
+	int fifo;
+	int tmp;
+
+	if (!dwc->do_fifo_resize)
+		return 0;
+
+	/* resize IN endpoints except ep0 */
+	if (!usb_endpoint_dir_in(dep->endpoint.desc) || dep->number <= 1)
+		return 0;
+
+	/* bail if already resized */
+	if (dep->flags & DWC3_EP_TXFIFO_RESIZED)
+		return 0;
+
+	ram1_depth = DWC3_RAM1_DEPTH(dwc->hwparams.hwparams7);
+
+	if ((dep->endpoint.maxburst > 1 &&
+	     usb_endpoint_xfer_bulk(dep->endpoint.desc)) ||
+	    usb_endpoint_xfer_isoc(dep->endpoint.desc))
+		num_fifos = 3;
+
+	if (dep->endpoint.maxburst > 6 &&
+	    (usb_endpoint_xfer_bulk(dep->endpoint.desc) ||
+	     usb_endpoint_xfer_isoc(dep->endpoint.desc)) && DWC3_IP_IS(DWC31))
+		num_fifos = dwc->tx_fifo_resize_max_num;
+
+	/* FIFO size for a single buffer */
+	fifo = dwc3_gadget_calc_tx_fifo_size(dwc, 1);
+
+	/* Calculate the number of remaining EPs w/o any FIFO */
+	num_in_ep = dwc->max_cfg_eps;
+	num_in_ep -= dwc->num_ep_resized;
+
+	/* Reserve at least one FIFO for the number of IN EPs */
+	min_depth = num_in_ep * (fifo + 1);
+	remaining = ram1_depth - min_depth - dwc->last_fifo_depth;
+	remaining = max_t(int, 0, remaining);
+	/*
+	 * We've already reserved 1 FIFO per EP, so check what we can fit in
+	 * addition to it.  If there is not enough remaining space, allocate
+	 * all the remaining space to the EP.
+	 */
+	fifo_size = (num_fifos - 1) * fifo;
+	if (remaining < fifo_size)
+		fifo_size = remaining;
+
+	fifo_size += fifo;
+	/* Last increment according to the TX FIFO size equation */
+	fifo_size++;
+
+	/* Check if TXFIFOs start at non-zero addr */
+	tmp = dwc3_readl(dwc->regs, DWC3_GTXFIFOSIZ(0));
+	fifo_0_start = DWC3_GTXFIFOSIZ_TXFSTADDR(tmp);
+
+	fifo_size |= (fifo_0_start + (dwc->last_fifo_depth << 16));
+	if (DWC3_IP_IS(DWC3))
+		dwc->last_fifo_depth += DWC3_GTXFIFOSIZ_TXFDEP(fifo_size);
+	else
+		dwc->last_fifo_depth += DWC31_GTXFIFOSIZ_TXFDEP(fifo_size);
+
+	/* Check fifo size allocation doesn't exceed available RAM size. */
+	if (dwc->last_fifo_depth >= ram1_depth) {
+		dev_err(dwc->dev, "Fifosize(%d) > RAM size(%d) %s depth:%d\n",
+			dwc->last_fifo_depth, ram1_depth,
+			dep->endpoint.name, fifo_size);
+		if (DWC3_IP_IS(DWC3))
+			fifo_size = DWC3_GTXFIFOSIZ_TXFDEP(fifo_size);
+		else
+			fifo_size = DWC31_GTXFIFOSIZ_TXFDEP(fifo_size);
+
+		dwc->last_fifo_depth -= fifo_size;
+		return -ENOMEM;
+	}
+
+	dwc3_writel(dwc->regs, DWC3_GTXFIFOSIZ(dep->number >> 1), fifo_size);
+	dep->flags |= DWC3_EP_TXFIFO_RESIZED;
+	dwc->num_ep_resized++;
+
+	return 0;
+}
+
+/**
+ * __dwc3_gadget_ep_enable - initializes a hw endpoint
+ * @dep: endpoint to be initialized
+ * @action: one of INIT, MODIFY or RESTORE
+ *
+ * Caller should take care of locking. Execute all necessary commands to
+ * initialize a HW endpoint so it can be used by a gadget driver.
+ */
+static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep, unsigned int action)
+{
+	const struct usb_endpoint_descriptor *desc = dep->endpoint.desc;
+	struct dwc3		*dwc = dep->dwc;
+
+	u32			reg;
+	int			ret;
+
+	if (!(dep->flags & DWC3_EP_ENABLED)) {
+		ret = dwc3_gadget_resize_tx_fifos(dep);
+		if (ret)
+			return ret;
+
+		ret = dwc3_gadget_start_config(dep);
+		if (ret)
+			return ret;
+	}
+
+	ret = dwc3_gadget_set_ep_config(dep, action);
+	if (ret)
+		return ret;
+
+	if (!(dep->flags & DWC3_EP_ENABLED)) {
+		struct dwc3_trb	*trb_st_hw;
+		struct dwc3_trb	*trb_link;
+
+		dep->type = usb_endpoint_type(desc);
+		dep->flags |= DWC3_EP_ENABLED;
+
+		reg = dwc3_readl(dwc->regs, DWC3_DALEPENA);
+		reg |= DWC3_DALEPENA_EP(dep->number);
+		dwc3_writel(dwc->regs, DWC3_DALEPENA, reg);
+
+		dep->trb_dequeue = 0;
+		dep->trb_enqueue = 0;
+
+		if (usb_endpoint_xfer_control(desc))
+			goto out;
+
+		/* Initialize the TRB ring */
+		memset(dep->trb_pool, 0,
+		       sizeof(struct dwc3_trb) * DWC3_TRB_NUM);
+
+		/* Link TRB. The HWO bit is never reset */
+		trb_st_hw = &dep->trb_pool[0];
+
+		trb_link = &dep->trb_pool[DWC3_TRB_NUM - 1];
+		trb_link->bpl = lower_32_bits(dwc3_trb_dma_offset(dep, trb_st_hw));
+		trb_link->bph = upper_32_bits(dwc3_trb_dma_offset(dep, trb_st_hw));
+		trb_link->ctrl |= DWC3_TRBCTL_LINK_TRB;
+		trb_link->ctrl |= DWC3_TRB_CTRL_HWO;
+	}
+
+	/*
+	 * Issue StartTransfer here with no-op TRB so we can always rely on No
+	 * Response Update Transfer command.
+	 */
+	if (usb_endpoint_xfer_bulk(desc) ||
+			usb_endpoint_xfer_int(desc)) {
+		struct dwc3_gadget_ep_cmd_params params;
+		struct dwc3_trb	*trb;
+		dma_addr_t trb_dma;
+		u32 cmd;
+
+		memset(&params, 0, sizeof(params));
+		trb = &dep->trb_pool[0];
+		trb_dma = dwc3_trb_dma_offset(dep, trb);
+
+		params.param0 = upper_32_bits(trb_dma);
+		params.param1 = lower_32_bits(trb_dma);
+
+		cmd = DWC3_DEPCMD_STARTTRANSFER;
+
+		ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
+		if (ret < 0)
+			return ret;
+
+		if (dep->stream_capable) {
+			/*
+			 * For streams, at start, there maybe a race where the
+			 * host primes the endpoint before the function driver
+			 * queues a request to initiate a stream. In that case,
+			 * the controller will not see the prime to generate the
+			 * ERDY and start stream. To workaround this, issue a
+			 * no-op TRB as normal, but end it immediately. As a
+			 * result, when the function driver queues the request,
+			 * the next START_TRANSFER command will cause the
+			 * controller to generate an ERDY to initiate the
+			 * stream.
+			 */
+			dwc3_stop_active_transfer(dep, true, true);
+
+			/*
+			 * All stream eps will reinitiate stream on NoStream
+			 * rejection until we can determine that the host can
+			 * prime after the first transfer.
+			 *
+			 * However, if the controller is capable of
+			 * TXF_FLUSH_BYPASS, then IN direction endpoints will
+			 * automatically restart the stream without the driver
+			 * initiation.
+			 */
+			if (!dep->direction ||
+			    !(dwc->hwparams.hwparams9 &
+			      DWC3_GHWPARAMS9_DEV_TXF_FLUSH_BYPASS))
+				dep->flags |= DWC3_EP_FORCE_RESTART_STREAM;
+		}
+	}
+
+out:
+	trace_dwc3_gadget_ep_enable(dep);
+
+	return 0;
+}
+
+void dwc3_remove_requests(struct dwc3 *dwc, struct dwc3_ep *dep, int status)
+{
+	struct dwc3_request		*req;
+
+	dwc3_stop_active_transfer(dep, true, false);
+
+	/* If endxfer is delayed, avoid unmapping requests */
+	if (dep->flags & DWC3_EP_DELAY_STOP)
+		return;
+
+	/* - giveback all requests to gadget driver */
+	while (!list_empty(&dep->started_list)) {
+		req = next_request(&dep->started_list);
+
+		dwc3_gadget_giveback(dep, req, status);
+	}
+
+	while (!list_empty(&dep->pending_list)) {
+		req = next_request(&dep->pending_list);
+
+		dwc3_gadget_giveback(dep, req, status);
+	}
+
+	while (!list_empty(&dep->cancelled_list)) {
+		req = next_request(&dep->cancelled_list);
+
+		dwc3_gadget_giveback(dep, req, status);
+	}
+}
+
+/**
+ * __dwc3_gadget_ep_disable - disables a hw endpoint
+ * @dep: the endpoint to disable
+ *
+ * This function undoes what __dwc3_gadget_ep_enable did and also removes
+ * requests which are currently being processed by the hardware and those which
+ * are not yet scheduled.
+ *
+ * Caller should take care of locking.
+ */
+static int __dwc3_gadget_ep_disable(struct dwc3_ep *dep)
+{
+	struct dwc3		*dwc = dep->dwc;
+	u32			reg;
+	u32			mask;
+
+	trace_dwc3_gadget_ep_disable(dep);
+
+	/* make sure HW endpoint isn't stalled */
+	if (dep->flags & DWC3_EP_STALL)
+		__dwc3_gadget_ep_set_halt(dep, 0, false);
+
+	reg = dwc3_readl(dwc->regs, DWC3_DALEPENA);
+	reg &= ~DWC3_DALEPENA_EP(dep->number);
+	dwc3_writel(dwc->regs, DWC3_DALEPENA, reg);
+
+	dwc3_remove_requests(dwc, dep, -ESHUTDOWN);
+
+	dep->stream_capable = false;
+	dep->type = 0;
+	mask = DWC3_EP_TXFIFO_RESIZED;
+	/*
+	 * dwc3_remove_requests() can exit early if DWC3 EP delayed stop is
+	 * set.  Do not clear DEP flags, so that the end transfer command will
+	 * be reattempted during the next SETUP stage.
+	 */
+	if (dep->flags & DWC3_EP_DELAY_STOP)
+		mask |= (DWC3_EP_DELAY_STOP | DWC3_EP_TRANSFER_STARTED);
+	dep->flags &= mask;
+
+	/* Clear out the ep descriptors for non-ep0 */
+	if (dep->number > 1) {
+		dep->endpoint.comp_desc = NULL;
+		dep->endpoint.desc = NULL;
+	}
+
+	return 0;
+}
+
+/* -------------------------------------------------------------------------- */
+
+static int dwc3_gadget_ep0_enable(struct usb_ep *ep,
+		const struct usb_endpoint_descriptor *desc)
+{
+	return -EINVAL;
+}
+
+static int dwc3_gadget_ep0_disable(struct usb_ep *ep)
+{
+	return -EINVAL;
+}
+
+/* -------------------------------------------------------------------------- */
+
+static int dwc3_gadget_ep_enable(struct usb_ep *ep,
+		const struct usb_endpoint_descriptor *desc)
+{
+	struct dwc3_ep			*dep;
+	struct dwc3			*dwc;
+	unsigned long			flags;
+	int				ret;
+
+	if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
+		pr_debug("dwc3: invalid parameters\n");
+		return -EINVAL;
+	}
+
+	if (!desc->wMaxPacketSize) {
+		pr_debug("dwc3: missing wMaxPacketSize\n");
+		return -EINVAL;
+	}
+
+	dep = to_dwc3_ep(ep);
+	dwc = dep->dwc;
+
+	if (dev_WARN_ONCE(dwc->dev, dep->flags & DWC3_EP_ENABLED,
+					"%s is already enabled\n",
+					dep->name))
+		return 0;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_INIT);
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return ret;
+}
+
+static int dwc3_gadget_ep_disable(struct usb_ep *ep)
+{
+	struct dwc3_ep			*dep;
+	struct dwc3			*dwc;
+	unsigned long			flags;
+	int				ret;
+
+	if (!ep) {
+		pr_debug("dwc3: invalid parameters\n");
+		return -EINVAL;
+	}
+
+	dep = to_dwc3_ep(ep);
+	dwc = dep->dwc;
+
+	if (dev_WARN_ONCE(dwc->dev, !(dep->flags & DWC3_EP_ENABLED),
+					"%s is already disabled\n",
+					dep->name))
+		return 0;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	ret = __dwc3_gadget_ep_disable(dep);
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return ret;
+}
+
+static struct usb_request *dwc3_gadget_ep_alloc_request(struct usb_ep *ep,
+		gfp_t gfp_flags)
+{
+	struct dwc3_request		*req;
+	struct dwc3_ep			*dep = to_dwc3_ep(ep);
+
+	req = kzalloc(sizeof(*req), gfp_flags);
+	if (!req)
+		return NULL;
+
+	req->direction	= dep->direction;
+	req->epnum	= dep->number;
+	req->dep	= dep;
+	req->status	= DWC3_REQUEST_STATUS_UNKNOWN;
+
+	trace_dwc3_alloc_request(req);
+
+	return &req->request;
+}
+
+static void dwc3_gadget_ep_free_request(struct usb_ep *ep,
+		struct usb_request *request)
+{
+	struct dwc3_request		*req = to_dwc3_request(request);
+
+	trace_dwc3_free_request(req);
+	kfree(req);
+}
+
+/**
+ * dwc3_ep_prev_trb - returns the previous TRB in the ring
+ * @dep: The endpoint with the TRB ring
+ * @index: The index of the current TRB in the ring
+ *
+ * Returns the TRB prior to the one pointed to by the index. If the
+ * index is 0, we will wrap backwards, skip the link TRB, and return
+ * the one just before that.
+ */
+static struct dwc3_trb *dwc3_ep_prev_trb(struct dwc3_ep *dep, u8 index)
+{
+	u8 tmp = index;
+
+	if (!tmp)
+		tmp = DWC3_TRB_NUM - 1;
+
+	return &dep->trb_pool[tmp - 1];
+}
+
+static u32 dwc3_calc_trbs_left(struct dwc3_ep *dep)
+{
+	u8			trbs_left;
+
+	/*
+	 * If the enqueue & dequeue are equal then the TRB ring is either full
+	 * or empty. It's considered full when there are DWC3_TRB_NUM-1 of TRBs
+	 * pending to be processed by the driver.
+	 */
+	if (dep->trb_enqueue == dep->trb_dequeue) {
+		/*
+		 * If there is any request remained in the started_list at
+		 * this point, that means there is no TRB available.
+		 */
+		if (!list_empty(&dep->started_list))
+			return 0;
+
+		return DWC3_TRB_NUM - 1;
+	}
+
+	trbs_left = dep->trb_dequeue - dep->trb_enqueue;
+	trbs_left &= (DWC3_TRB_NUM - 1);
+
+	if (dep->trb_dequeue < dep->trb_enqueue)
+		trbs_left--;
+
+	return trbs_left;
+}
+
+/**
+ * dwc3_prepare_one_trb - setup one TRB from one request
+ * @dep: endpoint for which this request is prepared
+ * @req: dwc3_request pointer
+ * @trb_length: buffer size of the TRB
+ * @chain: should this TRB be chained to the next?
+ * @node: only for isochronous endpoints. First TRB needs different type.
+ * @use_bounce_buffer: set to use bounce buffer
+ * @must_interrupt: set to interrupt on TRB completion
+ */
+static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
+		struct dwc3_request *req, unsigned int trb_length,
+		unsigned int chain, unsigned int node, bool use_bounce_buffer,
+		bool must_interrupt)
+{
+	struct dwc3_trb		*trb;
+	dma_addr_t		dma;
+	unsigned int		stream_id = req->request.stream_id;
+	unsigned int		short_not_ok = req->request.short_not_ok;
+	unsigned int		no_interrupt = req->request.no_interrupt;
+	unsigned int		is_last = req->request.is_last;
+	struct dwc3		*dwc = dep->dwc;
+	struct usb_gadget	*gadget = dwc->gadget;
+	enum usb_device_speed	speed = gadget->speed;
+
+	if (use_bounce_buffer)
+		dma = dep->dwc->bounce_addr;
+	else if (req->request.num_sgs > 0)
+		dma = sg_dma_address(req->start_sg);
+	else
+		dma = req->request.dma;
+
+	trb = &dep->trb_pool[dep->trb_enqueue];
+
+	if (!req->trb) {
+		dwc3_gadget_move_started_request(req);
+		req->trb = trb;
+		req->trb_dma = dwc3_trb_dma_offset(dep, trb);
+	}
+
+	req->num_trbs++;
+
+	trb->size = DWC3_TRB_SIZE_LENGTH(trb_length);
+	trb->bpl = lower_32_bits(dma);
+	trb->bph = upper_32_bits(dma);
+
+	switch (usb_endpoint_type(dep->endpoint.desc)) {
+	case USB_ENDPOINT_XFER_CONTROL:
+		trb->ctrl = DWC3_TRBCTL_CONTROL_SETUP;
+		break;
+
+	case USB_ENDPOINT_XFER_ISOC:
+		if (!node) {
+			trb->ctrl = DWC3_TRBCTL_ISOCHRONOUS_FIRST;
+
+			/*
+			 * USB Specification 2.0 Section 5.9.2 states that: "If
+			 * there is only a single transaction in the microframe,
+			 * only a DATA0 data packet PID is used.  If there are
+			 * two transactions per microframe, DATA1 is used for
+			 * the first transaction data packet and DATA0 is used
+			 * for the second transaction data packet.  If there are
+			 * three transactions per microframe, DATA2 is used for
+			 * the first transaction data packet, DATA1 is used for
+			 * the second, and DATA0 is used for the third."
+			 *
+			 * IOW, we should satisfy the following cases:
+			 *
+			 * 1) length <= maxpacket
+			 *	- DATA0
+			 *
+			 * 2) maxpacket < length <= (2 * maxpacket)
+			 *	- DATA1, DATA0
+			 *
+			 * 3) (2 * maxpacket) < length <= (3 * maxpacket)
+			 *	- DATA2, DATA1, DATA0
+			 */
+			if (speed == USB_SPEED_HIGH) {
+				struct usb_ep *ep = &dep->endpoint;
+				unsigned int mult = 2;
+				unsigned int maxp = usb_endpoint_maxp(ep->desc);
+
+				if (req->request.length <= (2 * maxp))
+					mult--;
+
+				if (req->request.length <= maxp)
+					mult--;
+
+				trb->size |= DWC3_TRB_SIZE_PCM1(mult);
+			}
+		} else {
+			trb->ctrl = DWC3_TRBCTL_ISOCHRONOUS;
+		}
+
+		if (!no_interrupt && !chain)
+			trb->ctrl |= DWC3_TRB_CTRL_ISP_IMI;
+		break;
+
+	case USB_ENDPOINT_XFER_BULK:
+	case USB_ENDPOINT_XFER_INT:
+		trb->ctrl = DWC3_TRBCTL_NORMAL;
+		break;
+	default:
+		/*
+		 * This is only possible with faulty memory because we
+		 * checked it already :)
+		 */
+		dev_WARN(dwc->dev, "Unknown endpoint type %d\n",
+				usb_endpoint_type(dep->endpoint.desc));
+	}
+
+	/*
+	 * Enable Continue on Short Packet
+	 * when endpoint is not a stream capable
+	 */
+	if (usb_endpoint_dir_out(dep->endpoint.desc)) {
+		if (!dep->stream_capable)
+			trb->ctrl |= DWC3_TRB_CTRL_CSP;
+
+		if (short_not_ok)
+			trb->ctrl |= DWC3_TRB_CTRL_ISP_IMI;
+	}
+
+	/* All TRBs setup for MST must set CSP=1 when LST=0 */
+	if (dep->stream_capable && DWC3_MST_CAPABLE(&dwc->hwparams))
+		trb->ctrl |= DWC3_TRB_CTRL_CSP;
+
+	if ((!no_interrupt && !chain) || must_interrupt)
+		trb->ctrl |= DWC3_TRB_CTRL_IOC;
+
+	if (chain)
+		trb->ctrl |= DWC3_TRB_CTRL_CHN;
+	else if (dep->stream_capable && is_last &&
+		 !DWC3_MST_CAPABLE(&dwc->hwparams))
+		trb->ctrl |= DWC3_TRB_CTRL_LST;
+
+	if (usb_endpoint_xfer_bulk(dep->endpoint.desc) && dep->stream_capable)
+		trb->ctrl |= DWC3_TRB_CTRL_SID_SOFN(stream_id);
+
+	/*
+	 * As per data book 4.2.3.2TRB Control Bit Rules section
+	 *
+	 * The controller autonomously checks the HWO field of a TRB to determine if the
+	 * entire TRB is valid. Therefore, software must ensure that the rest of the TRB
+	 * is valid before setting the HWO field to '1'. In most systems, this means that
+	 * software must update the fourth DWORD of a TRB last.
+	 *
+	 * However there is a possibility of CPU re-ordering here which can cause
+	 * controller to observe the HWO bit set prematurely.
+	 * Add a write memory barrier to prevent CPU re-ordering.
+	 */
+	wmb();
+	trb->ctrl |= DWC3_TRB_CTRL_HWO;
+
+	dwc3_ep_inc_enq(dep);
+
+	trace_dwc3_prepare_trb(dep, trb);
+}
+
+static bool dwc3_needs_extra_trb(struct dwc3_ep *dep, struct dwc3_request *req)
+{
+	unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
+	unsigned int rem = req->request.length % maxp;
+
+	if ((req->request.length && req->request.zero && !rem &&
+			!usb_endpoint_xfer_isoc(dep->endpoint.desc)) ||
+			(!req->direction && rem))
+		return true;
+
+	return false;
+}
+
+/**
+ * dwc3_prepare_last_sg - prepare TRBs for the last SG entry
+ * @dep: The endpoint that the request belongs to
+ * @req: The request to prepare
+ * @entry_length: The last SG entry size
+ * @node: Indicates whether this is not the first entry (for isoc only)
+ *
+ * Return the number of TRBs prepared.
+ */
+static int dwc3_prepare_last_sg(struct dwc3_ep *dep,
+		struct dwc3_request *req, unsigned int entry_length,
+		unsigned int node)
+{
+	unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
+	unsigned int rem = req->request.length % maxp;
+	unsigned int num_trbs = 1;
+
+	if (dwc3_needs_extra_trb(dep, req))
+		num_trbs++;
+
+	if (dwc3_calc_trbs_left(dep) < num_trbs)
+		return 0;
+
+	req->needs_extra_trb = num_trbs > 1;
+
+	/* Prepare a normal TRB */
+	if (req->direction || req->request.length)
+		dwc3_prepare_one_trb(dep, req, entry_length,
+				req->needs_extra_trb, node, false, false);
+
+	/* Prepare extra TRBs for ZLP and MPS OUT transfer alignment */
+	if ((!req->direction && !req->request.length) || req->needs_extra_trb)
+		dwc3_prepare_one_trb(dep, req,
+				req->direction ? 0 : maxp - rem,
+				false, 1, true, false);
+
+	return num_trbs;
+}
+
+static int dwc3_prepare_trbs_sg(struct dwc3_ep *dep,
+		struct dwc3_request *req)
+{
+	struct scatterlist *sg = req->start_sg;
+	struct scatterlist *s;
+	int		i;
+	unsigned int length = req->request.length;
+	unsigned int remaining = req->request.num_mapped_sgs
+		- req->num_queued_sgs;
+	unsigned int num_trbs = req->num_trbs;
+	bool needs_extra_trb = dwc3_needs_extra_trb(dep, req);
+
+	/*
+	 * If we resume preparing the request, then get the remaining length of
+	 * the request and resume where we left off.
+	 */
+	for_each_sg(req->request.sg, s, req->num_queued_sgs, i)
+		length -= sg_dma_len(s);
+
+	for_each_sg(sg, s, remaining, i) {
+		unsigned int num_trbs_left = dwc3_calc_trbs_left(dep);
+		unsigned int trb_length;
+		bool must_interrupt = false;
+		bool last_sg = false;
+
+		trb_length = min_t(unsigned int, length, sg_dma_len(s));
+
+		length -= trb_length;
+
+		/*
+		 * IOMMU driver is coalescing the list of sgs which shares a
+		 * page boundary into one and giving it to USB driver. With
+		 * this the number of sgs mapped is not equal to the number of
+		 * sgs passed. So mark the chain bit to false if it isthe last
+		 * mapped sg.
+		 */
+		if ((i == remaining - 1) || !length)
+			last_sg = true;
+
+		if (!num_trbs_left)
+			break;
+
+		if (last_sg) {
+			if (!dwc3_prepare_last_sg(dep, req, trb_length, i))
+				break;
+		} else {
+			/*
+			 * Look ahead to check if we have enough TRBs for the
+			 * next SG entry. If not, set interrupt on this TRB to
+			 * resume preparing the next SG entry when more TRBs are
+			 * free.
+			 */
+			if (num_trbs_left == 1 || (needs_extra_trb &&
+					num_trbs_left <= 2 &&
+					sg_dma_len(sg_next(s)) >= length)) {
+				struct dwc3_request *r;
+
+				/* Check if previous requests already set IOC */
+				list_for_each_entry(r, &dep->started_list, list) {
+					if (r != req && !r->request.no_interrupt)
+						break;
+
+					if (r == req)
+						must_interrupt = true;
+				}
+			}
+
+			dwc3_prepare_one_trb(dep, req, trb_length, 1, i, false,
+					must_interrupt);
+		}
+
+		/*
+		 * There can be a situation where all sgs in sglist are not
+		 * queued because of insufficient trb number. To handle this
+		 * case, update start_sg to next sg to be queued, so that
+		 * we have free trbs we can continue queuing from where we
+		 * previously stopped
+		 */
+		if (!last_sg)
+			req->start_sg = sg_next(s);
+
+		req->num_queued_sgs++;
+		req->num_pending_sgs--;
+
+		/*
+		 * The number of pending SG entries may not correspond to the
+		 * number of mapped SG entries. If all the data are queued, then
+		 * don't include unused SG entries.
+		 */
+		if (length == 0) {
+			req->num_pending_sgs = 0;
+			break;
+		}
+
+		if (must_interrupt)
+			break;
+	}
+
+	return req->num_trbs - num_trbs;
+}
+
+static int dwc3_prepare_trbs_linear(struct dwc3_ep *dep,
+		struct dwc3_request *req)
+{
+	return dwc3_prepare_last_sg(dep, req, req->request.length, 0);
+}
+
+/*
+ * dwc3_prepare_trbs - setup TRBs from requests
+ * @dep: endpoint for which requests are being prepared
+ *
+ * The function goes through the requests list and sets up TRBs for the
+ * transfers. The function returns once there are no more TRBs available or
+ * it runs out of requests.
+ *
+ * Returns the number of TRBs prepared or negative errno.
+ */
+static int dwc3_prepare_trbs(struct dwc3_ep *dep)
+{
+	struct dwc3_request	*req, *n;
+	int			ret = 0;
+
+	BUILD_BUG_ON_NOT_POWER_OF_2(DWC3_TRB_NUM);
+
+	/*
+	 * We can get in a situation where there's a request in the started list
+	 * but there weren't enough TRBs to fully kick it in the first time
+	 * around, so it has been waiting for more TRBs to be freed up.
+	 *
+	 * In that case, we should check if we have a request with pending_sgs
+	 * in the started list and prepare TRBs for that request first,
+	 * otherwise we will prepare TRBs completely out of order and that will
+	 * break things.
+	 */
+	list_for_each_entry(req, &dep->started_list, list) {
+		if (req->num_pending_sgs > 0) {
+			ret = dwc3_prepare_trbs_sg(dep, req);
+			if (!ret || req->num_pending_sgs)
+				return ret;
+		}
+
+		if (!dwc3_calc_trbs_left(dep))
+			return ret;
+
+		/*
+		 * Don't prepare beyond a transfer. In DWC_usb32, its transfer
+		 * burst capability may try to read and use TRBs beyond the
+		 * active transfer instead of stopping.
+		 */
+		if (dep->stream_capable && req->request.is_last &&
+		    !DWC3_MST_CAPABLE(&dep->dwc->hwparams))
+			return ret;
+	}
+
+	list_for_each_entry_safe(req, n, &dep->pending_list, list) {
+		struct dwc3	*dwc = dep->dwc;
+
+		ret = usb_gadget_map_request_by_dev(dwc->sysdev, &req->request,
+						    dep->direction);
+		if (ret)
+			return ret;
+
+		req->sg			= req->request.sg;
+		req->start_sg		= req->sg;
+		req->num_queued_sgs	= 0;
+		req->num_pending_sgs	= req->request.num_mapped_sgs;
+
+		if (req->num_pending_sgs > 0) {
+			ret = dwc3_prepare_trbs_sg(dep, req);
+			if (req->num_pending_sgs)
+				return ret;
+		} else {
+			ret = dwc3_prepare_trbs_linear(dep, req);
+		}
+
+		if (!ret || !dwc3_calc_trbs_left(dep))
+			return ret;
+
+		/*
+		 * Don't prepare beyond a transfer. In DWC_usb32, its transfer
+		 * burst capability may try to read and use TRBs beyond the
+		 * active transfer instead of stopping.
+		 */
+		if (dep->stream_capable && req->request.is_last &&
+		    !DWC3_MST_CAPABLE(&dwc->hwparams))
+			return ret;
+	}
+
+	return ret;
+}
+
+static void dwc3_gadget_ep_cleanup_cancelled_requests(struct dwc3_ep *dep);
+
+static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep)
+{
+	struct dwc3_gadget_ep_cmd_params params;
+	struct dwc3_request		*req;
+	int				starting;
+	int				ret;
+	u32				cmd;
+
+	/*
+	 * Note that it's normal to have no new TRBs prepared (i.e. ret == 0).
+	 * This happens when we need to stop and restart a transfer such as in
+	 * the case of reinitiating a stream or retrying an isoc transfer.
+	 */
+	ret = dwc3_prepare_trbs(dep);
+	if (ret < 0)
+		return ret;
+
+	starting = !(dep->flags & DWC3_EP_TRANSFER_STARTED);
+
+	/*
+	 * If there's no new TRB prepared and we don't need to restart a
+	 * transfer, there's no need to update the transfer.
+	 */
+	if (!ret && !starting)
+		return ret;
+
+	req = next_request(&dep->started_list);
+	if (!req) {
+		dep->flags |= DWC3_EP_PENDING_REQUEST;
+		return 0;
+	}
+
+	memset(&params, 0, sizeof(params));
+
+	if (starting) {
+		params.param0 = upper_32_bits(req->trb_dma);
+		params.param1 = lower_32_bits(req->trb_dma);
+		cmd = DWC3_DEPCMD_STARTTRANSFER;
+
+		if (dep->stream_capable)
+			cmd |= DWC3_DEPCMD_PARAM(req->request.stream_id);
+
+		if (usb_endpoint_xfer_isoc(dep->endpoint.desc))
+			cmd |= DWC3_DEPCMD_PARAM(dep->frame_number);
+	} else {
+		cmd = DWC3_DEPCMD_UPDATETRANSFER |
+			DWC3_DEPCMD_PARAM(dep->resource_index);
+	}
+
+	ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
+	if (ret < 0) {
+		struct dwc3_request *tmp;
+
+		if (ret == -EAGAIN)
+			return ret;
+
+		dwc3_stop_active_transfer(dep, true, true);
+
+		list_for_each_entry_safe(req, tmp, &dep->started_list, list)
+			dwc3_gadget_move_cancelled_request(req, DWC3_REQUEST_STATUS_DEQUEUED);
+
+		/* If ep isn't started, then there's no end transfer pending */
+		if (!(dep->flags & DWC3_EP_END_TRANSFER_PENDING))
+			dwc3_gadget_ep_cleanup_cancelled_requests(dep);
+
+		return ret;
+	}
+
+	if (dep->stream_capable && req->request.is_last &&
+	    !DWC3_MST_CAPABLE(&dep->dwc->hwparams))
+		dep->flags |= DWC3_EP_WAIT_TRANSFER_COMPLETE;
+
+	return 0;
+}
+
+static int __dwc3_gadget_get_frame(struct dwc3 *dwc)
+{
+	u32			reg;
+
+	reg = dwc3_readl(dwc->regs, DWC3_DSTS);
+	return DWC3_DSTS_SOFFN(reg);
+}
+
+/**
+ * __dwc3_stop_active_transfer - stop the current active transfer
+ * @dep: isoc endpoint
+ * @force: set forcerm bit in the command
+ * @interrupt: command complete interrupt after End Transfer command
+ *
+ * When setting force, the ForceRM bit will be set. In that case
+ * the controller won't update the TRB progress on command
+ * completion. It also won't clear the HWO bit in the TRB.
+ * The command will also not complete immediately in that case.
+ */
+static int __dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force, bool interrupt)
+{
+	struct dwc3 *dwc = dep->dwc;
+	struct dwc3_gadget_ep_cmd_params params;
+	u32 cmd;
+	int ret;
+
+	cmd = DWC3_DEPCMD_ENDTRANSFER;
+	cmd |= force ? DWC3_DEPCMD_HIPRI_FORCERM : 0;
+	cmd |= interrupt ? DWC3_DEPCMD_CMDIOC : 0;
+	cmd |= DWC3_DEPCMD_PARAM(dep->resource_index);
+	memset(&params, 0, sizeof(params));
+	ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
+	/*
+	 * If the End Transfer command was timed out while the device is
+	 * not in SETUP phase, it's possible that an incoming Setup packet
+	 * may prevent the command's completion. Let's retry when the
+	 * ep0state returns to EP0_SETUP_PHASE.
+	 */
+	if (ret == -ETIMEDOUT && dep->dwc->ep0state != EP0_SETUP_PHASE) {
+		dep->flags |= DWC3_EP_DELAY_STOP;
+		return 0;
+	}
+	WARN_ON_ONCE(ret);
+	dep->resource_index = 0;
+
+	if (!interrupt) {
+		if (!DWC3_IP_IS(DWC3) || DWC3_VER_IS_PRIOR(DWC3, 310A))
+			mdelay(1);
+		dep->flags &= ~DWC3_EP_TRANSFER_STARTED;
+	} else if (!ret) {
+		dep->flags |= DWC3_EP_END_TRANSFER_PENDING;
+	}
+
+	dep->flags &= ~DWC3_EP_DELAY_STOP;
+	return ret;
+}
+
+/**
+ * dwc3_gadget_start_isoc_quirk - workaround invalid frame number
+ * @dep: isoc endpoint
+ *
+ * This function tests for the correct combination of BIT[15:14] from the 16-bit
+ * microframe number reported by the XferNotReady event for the future frame
+ * number to start the isoc transfer.
+ *
+ * In DWC_usb31 version 1.70a-ea06 and prior, for highspeed and fullspeed
+ * isochronous IN, BIT[15:14] of the 16-bit microframe number reported by the
+ * XferNotReady event are invalid. The driver uses this number to schedule the
+ * isochronous transfer and passes it to the START TRANSFER command. Because
+ * this number is invalid, the command may fail. If BIT[15:14] matches the
+ * internal 16-bit microframe, the START TRANSFER command will pass and the
+ * transfer will start at the scheduled time, if it is off by 1, the command
+ * will still pass, but the transfer will start 2 seconds in the future. For all
+ * other conditions, the START TRANSFER command will fail with bus-expiry.
+ *
+ * In order to workaround this issue, we can test for the correct combination of
+ * BIT[15:14] by sending START TRANSFER commands with different values of
+ * BIT[15:14]: 'b00, 'b01, 'b10, and 'b11. Each combination is 2^14 uframe apart
+ * (or 2 seconds). 4 seconds into the future will result in a bus-expiry status.
+ * As the result, within the 4 possible combinations for BIT[15:14], there will
+ * be 2 successful and 2 failure START COMMAND status. One of the 2 successful
+ * command status will result in a 2-second delay start. The smaller BIT[15:14]
+ * value is the correct combination.
+ *
+ * Since there are only 4 outcomes and the results are ordered, we can simply
+ * test 2 START TRANSFER commands with BIT[15:14] combinations 'b00 and 'b01 to
+ * deduce the smaller successful combination.
+ *
+ * Let test0 = test status for combination 'b00 and test1 = test status for 'b01
+ * of BIT[15:14]. The correct combination is as follow:
+ *
+ * if test0 fails and test1 passes, BIT[15:14] is 'b01
+ * if test0 fails and test1 fails, BIT[15:14] is 'b10
+ * if test0 passes and test1 fails, BIT[15:14] is 'b11
+ * if test0 passes and test1 passes, BIT[15:14] is 'b00
+ *
+ * Synopsys STAR 9001202023: Wrong microframe number for isochronous IN
+ * endpoints.
+ */
+static int dwc3_gadget_start_isoc_quirk(struct dwc3_ep *dep)
+{
+	int cmd_status = 0;
+	bool test0;
+	bool test1;
+
+	while (dep->combo_num < 2) {
+		struct dwc3_gadget_ep_cmd_params params;
+		u32 test_frame_number;
+		u32 cmd;
+
+		/*
+		 * Check if we can start isoc transfer on the next interval or
+		 * 4 uframes in the future with BIT[15:14] as dep->combo_num
+		 */
+		test_frame_number = dep->frame_number & DWC3_FRNUMBER_MASK;
+		test_frame_number |= dep->combo_num << 14;
+		test_frame_number += max_t(u32, 4, dep->interval);
+
+		params.param0 = upper_32_bits(dep->dwc->bounce_addr);
+		params.param1 = lower_32_bits(dep->dwc->bounce_addr);
+
+		cmd = DWC3_DEPCMD_STARTTRANSFER;
+		cmd |= DWC3_DEPCMD_PARAM(test_frame_number);
+		cmd_status = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
+
+		/* Redo if some other failure beside bus-expiry is received */
+		if (cmd_status && cmd_status != -EAGAIN) {
+			dep->start_cmd_status = 0;
+			dep->combo_num = 0;
+			return 0;
+		}
+
+		/* Store the first test status */
+		if (dep->combo_num == 0)
+			dep->start_cmd_status = cmd_status;
+
+		dep->combo_num++;
+
+		/*
+		 * End the transfer if the START_TRANSFER command is successful
+		 * to wait for the next XferNotReady to test the command again
+		 */
+		if (cmd_status == 0) {
+			dwc3_stop_active_transfer(dep, true, true);
+			return 0;
+		}
+	}
+
+	/* test0 and test1 are both completed at this point */
+	test0 = (dep->start_cmd_status == 0);
+	test1 = (cmd_status == 0);
+
+	if (!test0 && test1)
+		dep->combo_num = 1;
+	else if (!test0 && !test1)
+		dep->combo_num = 2;
+	else if (test0 && !test1)
+		dep->combo_num = 3;
+	else if (test0 && test1)
+		dep->combo_num = 0;
+
+	dep->frame_number &= DWC3_FRNUMBER_MASK;
+	dep->frame_number |= dep->combo_num << 14;
+	dep->frame_number += max_t(u32, 4, dep->interval);
+
+	/* Reinitialize test variables */
+	dep->start_cmd_status = 0;
+	dep->combo_num = 0;
+
+	return __dwc3_gadget_kick_transfer(dep);
+}
+
+static int __dwc3_gadget_start_isoc(struct dwc3_ep *dep)
+{
+	const struct usb_endpoint_descriptor *desc = dep->endpoint.desc;
+	struct dwc3 *dwc = dep->dwc;
+	int ret;
+	int i;
+
+	if (list_empty(&dep->pending_list) &&
+	    list_empty(&dep->started_list)) {
+		dep->flags |= DWC3_EP_PENDING_REQUEST;
+		return -EAGAIN;
+	}
+
+	if (!dwc->dis_start_transfer_quirk &&
+	    (DWC3_VER_IS_PRIOR(DWC31, 170A) ||
+	     DWC3_VER_TYPE_IS_WITHIN(DWC31, 170A, EA01, EA06))) {
+		if (dwc->gadget->speed <= USB_SPEED_HIGH && dep->direction)
+			return dwc3_gadget_start_isoc_quirk(dep);
+	}
+
+	if (desc->bInterval <= 14 &&
+	    dwc->gadget->speed >= USB_SPEED_HIGH) {
+		u32 frame = __dwc3_gadget_get_frame(dwc);
+		bool rollover = frame <
+				(dep->frame_number & DWC3_FRNUMBER_MASK);
+
+		/*
+		 * frame_number is set from XferNotReady and may be already
+		 * out of date. DSTS only provides the lower 14 bit of the
+		 * current frame number. So add the upper two bits of
+		 * frame_number and handle a possible rollover.
+		 * This will provide the correct frame_number unless more than
+		 * rollover has happened since XferNotReady.
+		 */
+
+		dep->frame_number = (dep->frame_number & ~DWC3_FRNUMBER_MASK) |
+				     frame;
+		if (rollover)
+			dep->frame_number += BIT(14);
+	}
+
+	for (i = 0; i < DWC3_ISOC_MAX_RETRIES; i++) {
+		int future_interval = i + 1;
+
+		/* Give the controller at least 500us to schedule transfers */
+		if (desc->bInterval < 3)
+			future_interval += 3 - desc->bInterval;
+
+		dep->frame_number = DWC3_ALIGN_FRAME(dep, future_interval);
+
+		ret = __dwc3_gadget_kick_transfer(dep);
+		if (ret != -EAGAIN)
+			break;
+	}
+
+	/*
+	 * After a number of unsuccessful start attempts due to bus-expiry
+	 * status, issue END_TRANSFER command and retry on the next XferNotReady
+	 * event.
+	 */
+	if (ret == -EAGAIN)
+		ret = __dwc3_stop_active_transfer(dep, false, true);
+
+	return ret;
+}
+
+static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
+{
+	struct dwc3		*dwc = dep->dwc;
+
+	if (!dep->endpoint.desc || !dwc->pullups_connected || !dwc->connected) {
+		dev_dbg(dwc->dev, "%s: can't queue to disabled endpoint\n",
+				dep->name);
+		return -ESHUTDOWN;
+	}
+
+	if (WARN(req->dep != dep, "request %pK belongs to '%s'\n",
+				&req->request, req->dep->name))
+		return -EINVAL;
+
+	if (WARN(req->status < DWC3_REQUEST_STATUS_COMPLETED,
+				"%s: request %pK already in flight\n",
+				dep->name, &req->request))
+		return -EINVAL;
+
+	pm_runtime_get(dwc->dev);
+
+	req->request.actual	= 0;
+	req->request.status	= -EINPROGRESS;
+
+	trace_dwc3_ep_queue(req);
+
+	list_add_tail(&req->list, &dep->pending_list);
+	req->status = DWC3_REQUEST_STATUS_QUEUED;
+
+	if (dep->flags & DWC3_EP_WAIT_TRANSFER_COMPLETE)
+		return 0;
+
+	/*
+	 * Start the transfer only after the END_TRANSFER is completed
+	 * and endpoint STALL is cleared.
+	 */
+	if ((dep->flags & DWC3_EP_END_TRANSFER_PENDING) ||
+	    (dep->flags & DWC3_EP_WEDGE) ||
+	    (dep->flags & DWC3_EP_DELAY_STOP) ||
+	    (dep->flags & DWC3_EP_STALL)) {
+		dep->flags |= DWC3_EP_DELAY_START;
+		return 0;
+	}
+
+	/*
+	 * NOTICE: Isochronous endpoints should NEVER be prestarted. We must
+	 * wait for a XferNotReady event so we will know what's the current
+	 * (micro-)frame number.
+	 *
+	 * Without this trick, we are very, very likely gonna get Bus Expiry
+	 * errors which will force us issue EndTransfer command.
+	 */
+	if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
+		if (!(dep->flags & DWC3_EP_TRANSFER_STARTED)) {
+			if ((dep->flags & DWC3_EP_PENDING_REQUEST))
+				return __dwc3_gadget_start_isoc(dep);
+
+			return 0;
+		}
+	}
+
+	__dwc3_gadget_kick_transfer(dep);
+
+	return 0;
+}
+
+static int dwc3_gadget_ep_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;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	ret = __dwc3_gadget_ep_queue(dep, req);
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return ret;
+}
+
+static void dwc3_gadget_ep_skip_trbs(struct dwc3_ep *dep, struct dwc3_request *req)
+{
+	int i;
+
+	/* If req->trb is not set, then the request has not started */
+	if (!req->trb)
+		return;
+
+	/*
+	 * If request was already started, this means we had to
+	 * stop the transfer. With that we also need to ignore
+	 * all TRBs used by the request, however TRBs can only
+	 * be modified after completion of END_TRANSFER
+	 * command. So what we do here is that we wait for
+	 * END_TRANSFER completion and only after that, we jump
+	 * over TRBs by clearing HWO and incrementing dequeue
+	 * pointer.
+	 */
+	for (i = 0; i < req->num_trbs; i++) {
+		struct dwc3_trb *trb;
+
+		trb = &dep->trb_pool[dep->trb_dequeue];
+		trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
+		dwc3_ep_inc_deq(dep);
+	}
+
+	req->num_trbs = 0;
+}
+
+static void dwc3_gadget_ep_cleanup_cancelled_requests(struct dwc3_ep *dep)
+{
+	struct dwc3_request		*req;
+	struct dwc3			*dwc = dep->dwc;
+
+	while (!list_empty(&dep->cancelled_list)) {
+		req = next_request(&dep->cancelled_list);
+		dwc3_gadget_ep_skip_trbs(dep, req);
+		switch (req->status) {
+		case DWC3_REQUEST_STATUS_DISCONNECTED:
+			dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
+			break;
+		case DWC3_REQUEST_STATUS_DEQUEUED:
+			dwc3_gadget_giveback(dep, req, -ECONNRESET);
+			break;
+		case DWC3_REQUEST_STATUS_STALLED:
+			dwc3_gadget_giveback(dep, req, -EPIPE);
+			break;
+		default:
+			dev_err(dwc->dev, "request cancelled with wrong reason:%d\n", req->status);
+			dwc3_gadget_giveback(dep, req, -ECONNRESET);
+			break;
+		}
+		/*
+		 * The endpoint is disabled, let the dwc3_remove_requests()
+		 * handle the cleanup.
+		 */
+		if (!dep->endpoint.desc)
+			break;
+	}
+}
+
+static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
+		struct usb_request *request)
+{
+	struct dwc3_request		*req = to_dwc3_request(request);
+	struct dwc3_request		*r = NULL;
+
+	struct dwc3_ep			*dep = to_dwc3_ep(ep);
+	struct dwc3			*dwc = dep->dwc;
+
+	unsigned long			flags;
+	int				ret = 0;
+
+	trace_dwc3_ep_dequeue(req);
+
+	spin_lock_irqsave(&dwc->lock, flags);
+
+	list_for_each_entry(r, &dep->cancelled_list, list) {
+		if (r == req)
+			goto out;
+	}
+
+	list_for_each_entry(r, &dep->pending_list, list) {
+		if (r == req) {
+			/*
+			 * Explicitly check for EP0/1 as dequeue for those
+			 * EPs need to be handled differently.  Control EP
+			 * only deals with one USB req, and giveback will
+			 * occur during dwc3_ep0_stall_and_restart().  EP0
+			 * requests are never added to started_list.
+			 */
+			if (dep->number > 1)
+				dwc3_gadget_giveback(dep, req, -ECONNRESET);
+			else
+				dwc3_ep0_reset_state(dwc);
+			goto out;
+		}
+	}
+
+	list_for_each_entry(r, &dep->started_list, list) {
+		if (r == req) {
+			struct dwc3_request *t;
+
+			/* wait until it is processed */
+			dwc3_stop_active_transfer(dep, true, true);
+
+			/*
+			 * Remove any started request if the transfer is
+			 * cancelled.
+			 */
+			list_for_each_entry_safe(r, t, &dep->started_list, list)
+				dwc3_gadget_move_cancelled_request(r,
+						DWC3_REQUEST_STATUS_DEQUEUED);
+
+			dep->flags &= ~DWC3_EP_WAIT_TRANSFER_COMPLETE;
+
+			goto out;
+		}
+	}
+
+	dev_err(dwc->dev, "request %pK was not queued to %s\n",
+		request, ep->name);
+	ret = -EINVAL;
+out:
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return ret;
+}
+
+int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol)
+{
+	struct dwc3_gadget_ep_cmd_params	params;
+	struct dwc3				*dwc = dep->dwc;
+	struct dwc3_request			*req;
+	struct dwc3_request			*tmp;
+	int					ret;
+
+	if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
+		dev_err(dwc->dev, "%s is of Isochronous type\n", dep->name);
+		return -EINVAL;
+	}
+
+	memset(&params, 0x00, sizeof(params));
+
+	if (value) {
+		struct dwc3_trb *trb;
+
+		unsigned int transfer_in_flight;
+		unsigned int started;
+
+		if (dep->number > 1)
+			trb = dwc3_ep_prev_trb(dep, dep->trb_enqueue);
+		else
+			trb = &dwc->ep0_trb[dep->trb_enqueue];
+
+		transfer_in_flight = trb->ctrl & DWC3_TRB_CTRL_HWO;
+		started = !list_empty(&dep->started_list);
+
+		if (!protocol && ((dep->direction && transfer_in_flight) ||
+				(!dep->direction && started))) {
+			return -EAGAIN;
+		}
+
+		ret = dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETSTALL,
+				&params);
+		if (ret)
+			dev_err(dwc->dev, "failed to set STALL on %s\n",
+					dep->name);
+		else
+			dep->flags |= DWC3_EP_STALL;
+	} else {
+		/*
+		 * Don't issue CLEAR_STALL command to control endpoints. The
+		 * controller automatically clears the STALL when it receives
+		 * the SETUP token.
+		 */
+		if (dep->number <= 1) {
+			dep->flags &= ~(DWC3_EP_STALL | DWC3_EP_WEDGE);
+			return 0;
+		}
+
+		dwc3_stop_active_transfer(dep, true, true);
+
+		list_for_each_entry_safe(req, tmp, &dep->started_list, list)
+			dwc3_gadget_move_cancelled_request(req, DWC3_REQUEST_STATUS_STALLED);
+
+		if (dep->flags & DWC3_EP_END_TRANSFER_PENDING ||
+		    (dep->flags & DWC3_EP_DELAY_STOP)) {
+			dep->flags |= DWC3_EP_PENDING_CLEAR_STALL;
+			if (protocol)
+				dwc->clear_stall_protocol = dep->number;
+
+			return 0;
+		}
+
+		dwc3_gadget_ep_cleanup_cancelled_requests(dep);
+
+		ret = dwc3_send_clear_stall_ep_cmd(dep);
+		if (ret) {
+			dev_err(dwc->dev, "failed to clear STALL on %s\n",
+					dep->name);
+			return ret;
+		}
+
+		dep->flags &= ~(DWC3_EP_STALL | DWC3_EP_WEDGE);
+
+		if ((dep->flags & DWC3_EP_DELAY_START) &&
+		    !usb_endpoint_xfer_isoc(dep->endpoint.desc))
+			__dwc3_gadget_kick_transfer(dep);
+
+		dep->flags &= ~DWC3_EP_DELAY_START;
+	}
+
+	return ret;
+}
+
+static int dwc3_gadget_ep_set_halt(struct usb_ep *ep, int value)
+{
+	struct dwc3_ep			*dep = to_dwc3_ep(ep);
+	struct dwc3			*dwc = dep->dwc;
+
+	unsigned long			flags;
+
+	int				ret;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	ret = __dwc3_gadget_ep_set_halt(dep, value, false);
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return ret;
+}
+
+static int dwc3_gadget_ep_set_wedge(struct usb_ep *ep)
+{
+	struct dwc3_ep			*dep = to_dwc3_ep(ep);
+	struct dwc3			*dwc = dep->dwc;
+	unsigned long			flags;
+	int				ret;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	dep->flags |= DWC3_EP_WEDGE;
+
+	if (dep->number == 0 || dep->number == 1)
+		ret = __dwc3_gadget_ep0_set_halt(ep, 1);
+	else
+		ret = __dwc3_gadget_ep_set_halt(dep, 1, false);
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return ret;
+}
+
+/* -------------------------------------------------------------------------- */
+
+static struct usb_endpoint_descriptor dwc3_gadget_ep0_desc = {
+	.bLength	= USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType = USB_DT_ENDPOINT,
+	.bmAttributes	= USB_ENDPOINT_XFER_CONTROL,
+};
+
+static const struct usb_ep_ops dwc3_gadget_ep0_ops = {
+	.enable		= dwc3_gadget_ep0_enable,
+	.disable	= dwc3_gadget_ep0_disable,
+	.alloc_request	= dwc3_gadget_ep_alloc_request,
+	.free_request	= dwc3_gadget_ep_free_request,
+	.queue		= dwc3_gadget_ep0_queue,
+	.dequeue	= dwc3_gadget_ep_dequeue,
+	.set_halt	= dwc3_gadget_ep0_set_halt,
+	.set_wedge	= dwc3_gadget_ep_set_wedge,
+};
+
+static const struct usb_ep_ops dwc3_gadget_ep_ops = {
+	.enable		= dwc3_gadget_ep_enable,
+	.disable	= dwc3_gadget_ep_disable,
+	.alloc_request	= dwc3_gadget_ep_alloc_request,
+	.free_request	= dwc3_gadget_ep_free_request,
+	.queue		= dwc3_gadget_ep_queue,
+	.dequeue	= dwc3_gadget_ep_dequeue,
+	.set_halt	= dwc3_gadget_ep_set_halt,
+	.set_wedge	= dwc3_gadget_ep_set_wedge,
+};
+
+/* -------------------------------------------------------------------------- */
+
+static void dwc3_gadget_enable_linksts_evts(struct dwc3 *dwc, bool set)
+{
+	u32 reg;
+
+	if (DWC3_VER_IS_PRIOR(DWC3, 250A))
+		return;
+
+	reg = dwc3_readl(dwc->regs, DWC3_DEVTEN);
+	if (set)
+		reg |= DWC3_DEVTEN_ULSTCNGEN;
+	else
+		reg &= ~DWC3_DEVTEN_ULSTCNGEN;
+
+	dwc3_writel(dwc->regs, DWC3_DEVTEN, reg);
+}
+
+static int dwc3_gadget_get_frame(struct usb_gadget *g)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+
+	return __dwc3_gadget_get_frame(dwc);
+}
+
+static int __dwc3_gadget_wakeup(struct dwc3 *dwc, bool async)
+{
+	int			retries;
+
+	int			ret;
+	u32			reg;
+
+	u8			link_state;
+
+	/*
+	 * According to the Databook Remote wakeup request should
+	 * be issued only when the device is in early suspend state.
+	 *
+	 * We can check that via USB Link State bits in DSTS register.
+	 */
+	reg = dwc3_readl(dwc->regs, DWC3_DSTS);
+
+	link_state = DWC3_DSTS_USBLNKST(reg);
+
+	switch (link_state) {
+	case DWC3_LINK_STATE_RESET:
+	case DWC3_LINK_STATE_RX_DET:	/* in HS, means Early Suspend */
+	case DWC3_LINK_STATE_U3:	/* in HS, means SUSPEND */
+	case DWC3_LINK_STATE_U2:	/* in HS, means Sleep (L1) */
+	case DWC3_LINK_STATE_U1:
+	case DWC3_LINK_STATE_RESUME:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (async)
+		dwc3_gadget_enable_linksts_evts(dwc, true);
+
+	ret = dwc3_gadget_set_link_state(dwc, DWC3_LINK_STATE_RECOV);
+	if (ret < 0) {
+		dev_err(dwc->dev, "failed to put link in Recovery\n");
+		dwc3_gadget_enable_linksts_evts(dwc, false);
+		return ret;
+	}
+
+	/* Recent versions do this automatically */
+	if (DWC3_VER_IS_PRIOR(DWC3, 194A)) {
+		/* write zeroes to Link Change Request */
+		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+		reg &= ~DWC3_DCTL_ULSTCHNGREQ_MASK;
+		dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+	}
+
+	/*
+	 * Since link status change events are enabled we will receive
+	 * an U0 event when wakeup is successful. So bail out.
+	 */
+	if (async)
+		return 0;
+
+	/* poll until Link State changes to ON */
+	retries = 20000;
+
+	while (retries--) {
+		reg = dwc3_readl(dwc->regs, DWC3_DSTS);
+
+		/* in HS, means ON */
+		if (DWC3_DSTS_USBLNKST(reg) == DWC3_LINK_STATE_U0)
+			break;
+	}
+
+	if (DWC3_DSTS_USBLNKST(reg) != DWC3_LINK_STATE_U0) {
+		dev_err(dwc->dev, "failed to send remote wakeup\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int dwc3_gadget_wakeup(struct usb_gadget *g)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+	unsigned long		flags;
+	int			ret;
+
+	if (!dwc->wakeup_configured) {
+		dev_err(dwc->dev, "remote wakeup not configured\n");
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	if (!dwc->gadget->wakeup_armed) {
+		dev_err(dwc->dev, "not armed for remote wakeup\n");
+		spin_unlock_irqrestore(&dwc->lock, flags);
+		return -EINVAL;
+	}
+	ret = __dwc3_gadget_wakeup(dwc, true);
+
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return ret;
+}
+
+static void dwc3_resume_gadget(struct dwc3 *dwc);
+
+static int dwc3_gadget_func_wakeup(struct usb_gadget *g, int intf_id)
+{
+	struct  dwc3		*dwc = gadget_to_dwc(g);
+	unsigned long		flags;
+	int			ret;
+	int			link_state;
+
+	if (!dwc->wakeup_configured) {
+		dev_err(dwc->dev, "remote wakeup not configured\n");
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	/*
+	 * If the link is in U3, signal for remote wakeup and wait for the
+	 * link to transition to U0 before sending device notification.
+	 */
+	link_state = dwc3_gadget_get_link_state(dwc);
+	if (link_state == DWC3_LINK_STATE_U3) {
+		ret = __dwc3_gadget_wakeup(dwc, false);
+		if (ret) {
+			spin_unlock_irqrestore(&dwc->lock, flags);
+			return -EINVAL;
+		}
+		dwc3_resume_gadget(dwc);
+		dwc->suspended = false;
+		dwc->link_state = DWC3_LINK_STATE_U0;
+	}
+
+	ret = dwc3_send_gadget_generic_command(dwc, DWC3_DGCMD_DEV_NOTIFICATION,
+					       DWC3_DGCMDPAR_DN_FUNC_WAKE |
+					       DWC3_DGCMDPAR_INTF_SEL(intf_id));
+	if (ret)
+		dev_err(dwc->dev, "function remote wakeup failed, ret:%d\n", ret);
+
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return ret;
+}
+
+static int dwc3_gadget_set_remote_wakeup(struct usb_gadget *g, int set)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+	unsigned long		flags;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	dwc->wakeup_configured = !!set;
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return 0;
+}
+
+static int dwc3_gadget_set_selfpowered(struct usb_gadget *g,
+		int is_selfpowered)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+	unsigned long		flags;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	g->is_selfpowered = !!is_selfpowered;
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return 0;
+}
+
+static void dwc3_stop_active_transfers(struct dwc3 *dwc)
+{
+	u32 epnum;
+
+	for (epnum = 2; epnum < dwc->num_eps; epnum++) {
+		struct dwc3_ep *dep;
+
+		dep = dwc->eps[epnum];
+		if (!dep)
+			continue;
+
+		dwc3_remove_requests(dwc, dep, -ESHUTDOWN);
+	}
+}
+
+static void __dwc3_gadget_set_ssp_rate(struct dwc3 *dwc)
+{
+	enum usb_ssp_rate	ssp_rate = dwc->gadget_ssp_rate;
+	u32			reg;
+
+	if (ssp_rate == USB_SSP_GEN_UNKNOWN)
+		ssp_rate = dwc->max_ssp_rate;
+
+	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+	reg &= ~DWC3_DCFG_SPEED_MASK;
+	reg &= ~DWC3_DCFG_NUMLANES(~0);
+
+	if (ssp_rate == USB_SSP_GEN_1x2)
+		reg |= DWC3_DCFG_SUPERSPEED;
+	else if (dwc->max_ssp_rate != USB_SSP_GEN_1x2)
+		reg |= DWC3_DCFG_SUPERSPEED_PLUS;
+
+	if (ssp_rate != USB_SSP_GEN_2x1 &&
+	    dwc->max_ssp_rate != USB_SSP_GEN_2x1)
+		reg |= DWC3_DCFG_NUMLANES(1);
+
+	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+}
+
+static void __dwc3_gadget_set_speed(struct dwc3 *dwc)
+{
+	enum usb_device_speed	speed;
+	u32			reg;
+
+	speed = dwc->gadget_max_speed;
+	if (speed == USB_SPEED_UNKNOWN || speed > dwc->maximum_speed)
+		speed = dwc->maximum_speed;
+
+	if (speed == USB_SPEED_SUPER_PLUS &&
+	    DWC3_IP_IS(DWC32)) {
+		__dwc3_gadget_set_ssp_rate(dwc);
+		return;
+	}
+
+	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+	reg &= ~(DWC3_DCFG_SPEED_MASK);
+
+	/*
+	 * WORKAROUND: DWC3 revision < 2.20a have an issue
+	 * which would cause metastability state on Run/Stop
+	 * bit if we try to force the IP to USB2-only mode.
+	 *
+	 * Because of that, we cannot configure the IP to any
+	 * speed other than the SuperSpeed
+	 *
+	 * Refers to:
+	 *
+	 * STAR#9000525659: Clock Domain Crossing on DCTL in
+	 * USB 2.0 Mode
+	 */
+	if (DWC3_VER_IS_PRIOR(DWC3, 220A) &&
+	    !dwc->dis_metastability_quirk) {
+		reg |= DWC3_DCFG_SUPERSPEED;
+	} else {
+		switch (speed) {
+		case USB_SPEED_FULL:
+			reg |= DWC3_DCFG_FULLSPEED;
+			break;
+		case USB_SPEED_HIGH:
+			reg |= DWC3_DCFG_HIGHSPEED;
+			break;
+		case USB_SPEED_SUPER:
+			reg |= DWC3_DCFG_SUPERSPEED;
+			break;
+		case USB_SPEED_SUPER_PLUS:
+			if (DWC3_IP_IS(DWC3))
+				reg |= DWC3_DCFG_SUPERSPEED;
+			else
+				reg |= DWC3_DCFG_SUPERSPEED_PLUS;
+			break;
+		default:
+			dev_err(dwc->dev, "invalid speed (%d)\n", speed);
+
+			if (DWC3_IP_IS(DWC3))
+				reg |= DWC3_DCFG_SUPERSPEED;
+			else
+				reg |= DWC3_DCFG_SUPERSPEED_PLUS;
+		}
+	}
+
+	if (DWC3_IP_IS(DWC32) &&
+	    speed > USB_SPEED_UNKNOWN &&
+	    speed < USB_SPEED_SUPER_PLUS)
+		reg &= ~DWC3_DCFG_NUMLANES(~0);
+
+	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+}
+
+static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on)
+{
+	u32			reg;
+	u32			timeout = 2000;
+
+	if (pm_runtime_suspended(dwc->dev))
+		return 0;
+
+	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+	if (is_on) {
+		if (DWC3_VER_IS_WITHIN(DWC3, ANY, 187A)) {
+			reg &= ~DWC3_DCTL_TRGTULST_MASK;
+			reg |= DWC3_DCTL_TRGTULST_RX_DET;
+		}
+
+		if (!DWC3_VER_IS_PRIOR(DWC3, 194A))
+			reg &= ~DWC3_DCTL_KEEP_CONNECT;
+		reg |= DWC3_DCTL_RUN_STOP;
+
+		__dwc3_gadget_set_speed(dwc);
+		dwc->pullups_connected = true;
+	} else {
+		reg &= ~DWC3_DCTL_RUN_STOP;
+
+		dwc->pullups_connected = false;
+	}
+
+	dwc3_gadget_dctl_write_safe(dwc, reg);
+
+	do {
+		usleep_range(1000, 2000);
+		reg = dwc3_readl(dwc->regs, DWC3_DSTS);
+		reg &= DWC3_DSTS_DEVCTRLHLT;
+	} while (--timeout && !(!is_on ^ !reg));
+
+	if (!timeout)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static void dwc3_gadget_disable_irq(struct dwc3 *dwc);
+static void __dwc3_gadget_stop(struct dwc3 *dwc);
+static int __dwc3_gadget_start(struct dwc3 *dwc);
+
+static int dwc3_gadget_soft_disconnect(struct dwc3 *dwc)
+{
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	dwc->connected = false;
+
+	/*
+	 * Attempt to end pending SETUP status phase, and not wait for the
+	 * function to do so.
+	 */
+	if (dwc->delayed_status)
+		dwc3_ep0_send_delayed_status(dwc);
+
+	/*
+	 * In the Synopsys DesignWare Cores USB3 Databook Rev. 3.30a
+	 * Section 4.1.8 Table 4-7, it states that for a device-initiated
+	 * disconnect, the SW needs to ensure that it sends "a DEPENDXFER
+	 * command for any active transfers" before clearing the RunStop
+	 * bit.
+	 */
+	dwc3_stop_active_transfers(dwc);
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	/*
+	 * Per databook, when we want to stop the gadget, if a control transfer
+	 * is still in process, complete it and get the core into setup phase.
+	 * In case the host is unresponsive to a SETUP transaction, forcefully
+	 * stall the transfer, and move back to the SETUP phase, so that any
+	 * pending endxfers can be executed.
+	 */
+	if (dwc->ep0state != EP0_SETUP_PHASE) {
+		reinit_completion(&dwc->ep0_in_setup);
+
+		ret = wait_for_completion_timeout(&dwc->ep0_in_setup,
+				msecs_to_jiffies(DWC3_PULL_UP_TIMEOUT));
+		if (ret == 0) {
+			dev_warn(dwc->dev, "wait for SETUP phase timed out\n");
+			spin_lock_irqsave(&dwc->lock, flags);
+			dwc3_ep0_reset_state(dwc);
+			spin_unlock_irqrestore(&dwc->lock, flags);
+		}
+	}
+
+	/*
+	 * Note: if the GEVNTCOUNT indicates events in the event buffer, the
+	 * driver needs to acknowledge them before the controller can halt.
+	 * Simply let the interrupt handler acknowledges and handle the
+	 * remaining event generated by the controller while polling for
+	 * DSTS.DEVCTLHLT.
+	 */
+	ret = dwc3_gadget_run_stop(dwc, false);
+
+	/*
+	 * Stop the gadget after controller is halted, so that if needed, the
+	 * events to update EP0 state can still occur while the run/stop
+	 * routine polls for the halted state.  DEVTEN is cleared as part of
+	 * gadget stop.
+	 */
+	spin_lock_irqsave(&dwc->lock, flags);
+	__dwc3_gadget_stop(dwc);
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return ret;
+}
+
+static int dwc3_gadget_soft_connect(struct dwc3 *dwc)
+{
+	int ret;
+
+	/*
+	 * In the Synopsys DWC_usb31 1.90a programming guide section
+	 * 4.1.9, it specifies that for a reconnect after a
+	 * device-initiated disconnect requires a core soft reset
+	 * (DCTL.CSftRst) before enabling the run/stop bit.
+	 */
+	ret = dwc3_core_soft_reset(dwc);
+	if (ret)
+		return ret;
+
+	dwc3_event_buffers_setup(dwc);
+	__dwc3_gadget_start(dwc);
+	return dwc3_gadget_run_stop(dwc, true);
+}
+
+static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+	int			ret;
+
+	is_on = !!is_on;
+
+	dwc->softconnect = is_on;
+
+	/*
+	 * Avoid issuing a runtime resume if the device is already in the
+	 * suspended state during gadget disconnect.  DWC3 gadget was already
+	 * halted/stopped during runtime suspend.
+	 */
+	if (!is_on) {
+		pm_runtime_barrier(dwc->dev);
+		if (pm_runtime_suspended(dwc->dev))
+			return 0;
+	}
+
+	/*
+	 * Check the return value for successful resume, or error.  For a
+	 * successful resume, the DWC3 runtime PM resume routine will handle
+	 * the run stop sequence, so avoid duplicate operations here.
+	 */
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		if (ret < 0)
+			pm_runtime_set_suspended(dwc->dev);
+		return ret;
+	}
+
+	if (dwc->pullups_connected == is_on) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
+
+	synchronize_irq(dwc->irq_gadget);
+
+	if (!is_on)
+		ret = dwc3_gadget_soft_disconnect(dwc);
+	else
+		ret = dwc3_gadget_soft_connect(dwc);
+
+	pm_runtime_put(dwc->dev);
+
+	return ret;
+}
+
+static void dwc3_gadget_enable_irq(struct dwc3 *dwc)
+{
+	u32			reg;
+
+	/* Enable all but Start and End of Frame IRQs */
+	reg = (DWC3_DEVTEN_EVNTOVERFLOWEN |
+			DWC3_DEVTEN_CMDCMPLTEN |
+			DWC3_DEVTEN_ERRTICERREN |
+			DWC3_DEVTEN_WKUPEVTEN |
+			DWC3_DEVTEN_CONNECTDONEEN |
+			DWC3_DEVTEN_USBRSTEN |
+			DWC3_DEVTEN_DISCONNEVTEN);
+
+	if (DWC3_VER_IS_PRIOR(DWC3, 250A))
+		reg |= DWC3_DEVTEN_ULSTCNGEN;
+
+	/* On 2.30a and above this bit enables U3/L2-L1 Suspend Events */
+	if (!DWC3_VER_IS_PRIOR(DWC3, 230A))
+		reg |= DWC3_DEVTEN_U3L2L1SUSPEN;
+
+	dwc3_writel(dwc->regs, DWC3_DEVTEN, reg);
+}
+
+static void dwc3_gadget_disable_irq(struct dwc3 *dwc)
+{
+	/* mask all interrupts */
+	dwc3_writel(dwc->regs, DWC3_DEVTEN, 0x00);
+}
+
+static irqreturn_t dwc3_interrupt(int irq, void *_dwc);
+static irqreturn_t dwc3_thread_interrupt(int irq, void *_dwc);
+
+/**
+ * dwc3_gadget_setup_nump - calculate and initialize NUMP field of %DWC3_DCFG
+ * @dwc: pointer to our context structure
+ *
+ * The following looks like complex but it's actually very simple. In order to
+ * calculate the number of packets we can burst at once on OUT transfers, we're
+ * gonna use RxFIFO size.
+ *
+ * To calculate RxFIFO size we need two numbers:
+ * MDWIDTH = size, in bits, of the internal memory bus
+ * RAM2_DEPTH = depth, in MDWIDTH, of internal RAM2 (where RxFIFO sits)
+ *
+ * Given these two numbers, the formula is simple:
+ *
+ * RxFIFO Size = (RAM2_DEPTH * MDWIDTH / 8) - 24 - 16;
+ *
+ * 24 bytes is for 3x SETUP packets
+ * 16 bytes is a clock domain crossing tolerance
+ *
+ * Given RxFIFO Size, NUMP = RxFIFOSize / 1024;
+ */
+static void dwc3_gadget_setup_nump(struct dwc3 *dwc)
+{
+	u32 ram2_depth;
+	u32 mdwidth;
+	u32 nump;
+	u32 reg;
+
+	ram2_depth = DWC3_GHWPARAMS7_RAM2_DEPTH(dwc->hwparams.hwparams7);
+	mdwidth = dwc3_mdwidth(dwc);
+
+	nump = ((ram2_depth * mdwidth / 8) - 24 - 16) / 1024;
+	nump = min_t(u32, nump, 16);
+
+	/* update NumP */
+	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+	reg &= ~DWC3_DCFG_NUMP_MASK;
+	reg |= nump << DWC3_DCFG_NUMP_SHIFT;
+	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+}
+
+static int __dwc3_gadget_start(struct dwc3 *dwc)
+{
+	struct dwc3_ep		*dep;
+	int			ret = 0;
+	u32			reg;
+
+	/*
+	 * Use IMOD if enabled via dwc->imod_interval. Otherwise, if
+	 * the core supports IMOD, disable it.
+	 */
+	if (dwc->imod_interval) {
+		dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), dwc->imod_interval);
+		dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), DWC3_GEVNTCOUNT_EHB);
+	} else if (dwc3_has_imod(dwc)) {
+		dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), 0);
+	}
+
+	/*
+	 * We are telling dwc3 that we want to use DCFG.NUMP as ACK TP's NUMP
+	 * field instead of letting dwc3 itself calculate that automatically.
+	 *
+	 * This way, we maximize the chances that we'll be able to get several
+	 * bursts of data without going through any sort of endpoint throttling.
+	 */
+	reg = dwc3_readl(dwc->regs, DWC3_GRXTHRCFG);
+	if (DWC3_IP_IS(DWC3))
+		reg &= ~DWC3_GRXTHRCFG_PKTCNTSEL;
+	else
+		reg &= ~DWC31_GRXTHRCFG_PKTCNTSEL;
+
+	dwc3_writel(dwc->regs, DWC3_GRXTHRCFG, reg);
+
+	dwc3_gadget_setup_nump(dwc);
+
+	/*
+	 * Currently the controller handles single stream only. So, Ignore
+	 * Packet Pending bit for stream selection and don't search for another
+	 * stream if the host sends Data Packet with PP=0 (for OUT direction) or
+	 * ACK with NumP=0 and PP=0 (for IN direction). This slightly improves
+	 * the stream performance.
+	 */
+	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+	reg |= DWC3_DCFG_IGNSTRMPP;
+	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+
+	/* Enable MST by default if the device is capable of MST */
+	if (DWC3_MST_CAPABLE(&dwc->hwparams)) {
+		reg = dwc3_readl(dwc->regs, DWC3_DCFG1);
+		reg &= ~DWC3_DCFG1_DIS_MST_ENH;
+		dwc3_writel(dwc->regs, DWC3_DCFG1, reg);
+	}
+
+	/* Start with SuperSpeed Default */
+	dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
+
+	dep = dwc->eps[0];
+	dep->flags = 0;
+	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_INIT);
+	if (ret) {
+		dev_err(dwc->dev, "failed to enable %s\n", dep->name);
+		goto err0;
+	}
+
+	dep = dwc->eps[1];
+	dep->flags = 0;
+	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_INIT);
+	if (ret) {
+		dev_err(dwc->dev, "failed to enable %s\n", dep->name);
+		goto err1;
+	}
+
+	/* begin to receive SETUP packets */
+	dwc->ep0state = EP0_SETUP_PHASE;
+	dwc->ep0_bounced = false;
+	dwc->link_state = DWC3_LINK_STATE_SS_DIS;
+	dwc->delayed_status = false;
+	dwc3_ep0_out_start(dwc);
+
+	dwc3_gadget_enable_irq(dwc);
+
+	return 0;
+
+err1:
+	__dwc3_gadget_ep_disable(dwc->eps[0]);
+
+err0:
+	return ret;
+}
+
+static int dwc3_gadget_start(struct usb_gadget *g,
+		struct usb_gadget_driver *driver)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+	unsigned long		flags;
+	int			ret;
+	int			irq;
+
+	irq = dwc->irq_gadget;
+	ret = request_threaded_irq(irq, dwc3_interrupt, dwc3_thread_interrupt,
+			IRQF_SHARED, "dwc3", dwc->ev_buf);
+	if (ret) {
+		dev_err(dwc->dev, "failed to request irq #%d --> %d\n",
+				irq, ret);
+		return ret;
+	}
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	dwc->gadget_driver	= driver;
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return 0;
+}
+
+static void __dwc3_gadget_stop(struct dwc3 *dwc)
+{
+	dwc3_gadget_disable_irq(dwc);
+	__dwc3_gadget_ep_disable(dwc->eps[0]);
+	__dwc3_gadget_ep_disable(dwc->eps[1]);
+}
+
+static int dwc3_gadget_stop(struct usb_gadget *g)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+	unsigned long		flags;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	dwc->gadget_driver	= NULL;
+	dwc->max_cfg_eps = 0;
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	free_irq(dwc->irq_gadget, dwc->ev_buf);
+
+	return 0;
+}
+
+static void dwc3_gadget_config_params(struct usb_gadget *g,
+				      struct usb_dcd_config_params *params)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+
+	params->besl_baseline = USB_DEFAULT_BESL_UNSPECIFIED;
+	params->besl_deep = USB_DEFAULT_BESL_UNSPECIFIED;
+
+	/* Recommended BESL */
+	if (!dwc->dis_enblslpm_quirk) {
+		/*
+		 * If the recommended BESL baseline is 0 or if the BESL deep is
+		 * less than 2, Microsoft's Windows 10 host usb stack will issue
+		 * a usb reset immediately after it receives the extended BOS
+		 * descriptor and the enumeration will fail. To maintain
+		 * compatibility with the Windows' usb stack, let's set the
+		 * recommended BESL baseline to 1 and clamp the BESL deep to be
+		 * within 2 to 15.
+		 */
+		params->besl_baseline = 1;
+		if (dwc->is_utmi_l1_suspend)
+			params->besl_deep =
+				clamp_t(u8, dwc->hird_threshold, 2, 15);
+	}
+
+	/* U1 Device exit Latency */
+	if (dwc->dis_u1_entry_quirk)
+		params->bU1devExitLat = 0;
+	else
+		params->bU1devExitLat = DWC3_DEFAULT_U1_DEV_EXIT_LAT;
+
+	/* U2 Device exit Latency */
+	if (dwc->dis_u2_entry_quirk)
+		params->bU2DevExitLat = 0;
+	else
+		params->bU2DevExitLat =
+				cpu_to_le16(DWC3_DEFAULT_U2_DEV_EXIT_LAT);
+}
+
+static void dwc3_gadget_set_speed(struct usb_gadget *g,
+				  enum usb_device_speed speed)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+	unsigned long		flags;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	dwc->gadget_max_speed = speed;
+	spin_unlock_irqrestore(&dwc->lock, flags);
+}
+
+static void dwc3_gadget_set_ssp_rate(struct usb_gadget *g,
+				     enum usb_ssp_rate rate)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+	unsigned long		flags;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	dwc->gadget_max_speed = USB_SPEED_SUPER_PLUS;
+	dwc->gadget_ssp_rate = rate;
+	spin_unlock_irqrestore(&dwc->lock, flags);
+}
+
+static int dwc3_gadget_vbus_draw(struct usb_gadget *g, unsigned int mA)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+	union power_supply_propval	val = {0};
+	int				ret;
+
+	if (dwc->usb2_phy)
+		return usb_phy_set_power(dwc->usb2_phy, mA);
+
+	if (!dwc->usb_psy)
+		return -EOPNOTSUPP;
+
+	val.intval = 1000 * mA;
+	ret = power_supply_set_property(dwc->usb_psy, POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT, &val);
+
+	return ret;
+}
+
+/**
+ * dwc3_gadget_check_config - ensure dwc3 can support the USB configuration
+ * @g: pointer to the USB gadget
+ *
+ * Used to record the maximum number of endpoints being used in a USB composite
+ * device. (across all configurations)  This is to be used in the calculation
+ * of the TXFIFO sizes when resizing internal memory for individual endpoints.
+ * It will help ensured that the resizing logic reserves enough space for at
+ * least one max packet.
+ */
+static int dwc3_gadget_check_config(struct usb_gadget *g)
+{
+	struct dwc3 *dwc = gadget_to_dwc(g);
+	struct usb_ep *ep;
+	int fifo_size = 0;
+	int ram1_depth;
+	int ep_num = 0;
+
+	if (!dwc->do_fifo_resize)
+		return 0;
+
+	list_for_each_entry(ep, &g->ep_list, ep_list) {
+		/* Only interested in the IN endpoints */
+		if (ep->claimed && (ep->address & USB_DIR_IN))
+			ep_num++;
+	}
+
+	if (ep_num <= dwc->max_cfg_eps)
+		return 0;
+
+	/* Update the max number of eps in the composition */
+	dwc->max_cfg_eps = ep_num;
+
+	fifo_size = dwc3_gadget_calc_tx_fifo_size(dwc, dwc->max_cfg_eps);
+	/* Based on the equation, increment by one for every ep */
+	fifo_size += dwc->max_cfg_eps;
+
+	/* Check if we can fit a single fifo per endpoint */
+	ram1_depth = DWC3_RAM1_DEPTH(dwc->hwparams.hwparams7);
+	if (fifo_size > ram1_depth)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void dwc3_gadget_async_callbacks(struct usb_gadget *g, bool enable)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+	unsigned long		flags;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	dwc->async_callbacks = enable;
+	spin_unlock_irqrestore(&dwc->lock, flags);
+}
+
+static const struct usb_gadget_ops dwc3_gadget_ops = {
+	.get_frame		= dwc3_gadget_get_frame,
+	.wakeup			= dwc3_gadget_wakeup,
+	.func_wakeup		= dwc3_gadget_func_wakeup,
+	.set_remote_wakeup	= dwc3_gadget_set_remote_wakeup,
+	.set_selfpowered	= dwc3_gadget_set_selfpowered,
+	.pullup			= dwc3_gadget_pullup,
+	.udc_start		= dwc3_gadget_start,
+	.udc_stop		= dwc3_gadget_stop,
+	.udc_set_speed		= dwc3_gadget_set_speed,
+	.udc_set_ssp_rate	= dwc3_gadget_set_ssp_rate,
+	.get_config_params	= dwc3_gadget_config_params,
+	.vbus_draw		= dwc3_gadget_vbus_draw,
+	.check_config		= dwc3_gadget_check_config,
+	.udc_async_callbacks	= dwc3_gadget_async_callbacks,
+};
+
+/* -------------------------------------------------------------------------- */
+
+static int dwc3_gadget_init_control_endpoint(struct dwc3_ep *dep)
+{
+	struct dwc3 *dwc = dep->dwc;
+
+	usb_ep_set_maxpacket_limit(&dep->endpoint, 512);
+	dep->endpoint.maxburst = 1;
+	dep->endpoint.ops = &dwc3_gadget_ep0_ops;
+	if (!dep->direction)
+		dwc->gadget->ep0 = &dep->endpoint;
+
+	dep->endpoint.caps.type_control = true;
+
+	return 0;
+}
+
+static int dwc3_gadget_init_in_endpoint(struct dwc3_ep *dep)
+{
+	struct dwc3 *dwc = dep->dwc;
+	u32 mdwidth;
+	int size;
+	int maxpacket;
+
+	mdwidth = dwc3_mdwidth(dwc);
+
+	/* MDWIDTH is represented in bits, we need it in bytes */
+	mdwidth /= 8;
+
+	size = dwc3_readl(dwc->regs, DWC3_GTXFIFOSIZ(dep->number >> 1));
+	if (DWC3_IP_IS(DWC3))
+		size = DWC3_GTXFIFOSIZ_TXFDEP(size);
+	else
+		size = DWC31_GTXFIFOSIZ_TXFDEP(size);
+
+	/*
+	 * maxpacket size is determined as part of the following, after assuming
+	 * a mult value of one maxpacket:
+	 * DWC3 revision 280A and prior:
+	 * fifo_size = mult * (max_packet / mdwidth) + 1;
+	 * maxpacket = mdwidth * (fifo_size - 1);
+	 *
+	 * DWC3 revision 290A and onwards:
+	 * fifo_size = mult * ((max_packet + mdwidth)/mdwidth + 1) + 1
+	 * maxpacket = mdwidth * ((fifo_size - 1) - 1) - mdwidth;
+	 */
+	if (DWC3_VER_IS_PRIOR(DWC3, 290A))
+		maxpacket = mdwidth * (size - 1);
+	else
+		maxpacket = mdwidth * ((size - 1) - 1) - mdwidth;
+
+	/* Functionally, space for one max packet is sufficient */
+	size = min_t(int, maxpacket, 1024);
+	usb_ep_set_maxpacket_limit(&dep->endpoint, size);
+
+	dep->endpoint.max_streams = 16;
+	dep->endpoint.ops = &dwc3_gadget_ep_ops;
+	list_add_tail(&dep->endpoint.ep_list,
+			&dwc->gadget->ep_list);
+	dep->endpoint.caps.type_iso = true;
+	dep->endpoint.caps.type_bulk = true;
+	dep->endpoint.caps.type_int = true;
+
+	return dwc3_alloc_trb_pool(dep);
+}
+
+static int dwc3_gadget_init_out_endpoint(struct dwc3_ep *dep)
+{
+	struct dwc3 *dwc = dep->dwc;
+	u32 mdwidth;
+	int size;
+
+	mdwidth = dwc3_mdwidth(dwc);
+
+	/* MDWIDTH is represented in bits, convert to bytes */
+	mdwidth /= 8;
+
+	/* All OUT endpoints share a single RxFIFO space */
+	size = dwc3_readl(dwc->regs, DWC3_GRXFIFOSIZ(0));
+	if (DWC3_IP_IS(DWC3))
+		size = DWC3_GRXFIFOSIZ_RXFDEP(size);
+	else
+		size = DWC31_GRXFIFOSIZ_RXFDEP(size);
+
+	/* FIFO depth is in MDWDITH bytes */
+	size *= mdwidth;
+
+	/*
+	 * To meet performance requirement, a minimum recommended RxFIFO size
+	 * is defined as follow:
+	 * RxFIFO size >= (3 x MaxPacketSize) +
+	 * (3 x 8 bytes setup packets size) + (16 bytes clock crossing margin)
+	 *
+	 * Then calculate the max packet limit as below.
+	 */
+	size -= (3 * 8) + 16;
+	if (size < 0)
+		size = 0;
+	else
+		size /= 3;
+
+	usb_ep_set_maxpacket_limit(&dep->endpoint, size);
+	dep->endpoint.max_streams = 16;
+	dep->endpoint.ops = &dwc3_gadget_ep_ops;
+	list_add_tail(&dep->endpoint.ep_list,
+			&dwc->gadget->ep_list);
+	dep->endpoint.caps.type_iso = true;
+	dep->endpoint.caps.type_bulk = true;
+	dep->endpoint.caps.type_int = true;
+
+	return dwc3_alloc_trb_pool(dep);
+}
+
+static int dwc3_gadget_init_endpoint(struct dwc3 *dwc, u8 epnum)
+{
+	struct dwc3_ep			*dep;
+	bool				direction = epnum & 1;
+	int				ret;
+	u8				num = epnum >> 1;
+
+	dep = kzalloc(sizeof(*dep), GFP_KERNEL);
+	if (!dep)
+		return -ENOMEM;
+
+	dep->dwc = dwc;
+	dep->number = epnum;
+	dep->direction = direction;
+	dep->regs = dwc->regs + DWC3_DEP_BASE(epnum);
+	dwc->eps[epnum] = dep;
+	dep->combo_num = 0;
+	dep->start_cmd_status = 0;
+
+	snprintf(dep->name, sizeof(dep->name), "ep%u%s", num,
+			direction ? "in" : "out");
+
+	dep->endpoint.name = dep->name;
+
+	if (!(dep->number > 1)) {
+		dep->endpoint.desc = &dwc3_gadget_ep0_desc;
+		dep->endpoint.comp_desc = NULL;
+	}
+
+	if (num == 0)
+		ret = dwc3_gadget_init_control_endpoint(dep);
+	else if (direction)
+		ret = dwc3_gadget_init_in_endpoint(dep);
+	else
+		ret = dwc3_gadget_init_out_endpoint(dep);
+
+	if (ret)
+		return ret;
+
+	dep->endpoint.caps.dir_in = direction;
+	dep->endpoint.caps.dir_out = !direction;
+
+	INIT_LIST_HEAD(&dep->pending_list);
+	INIT_LIST_HEAD(&dep->started_list);
+	INIT_LIST_HEAD(&dep->cancelled_list);
+
+	dwc3_debugfs_create_endpoint_dir(dep);
+
+	return 0;
+}
+
+static int dwc3_gadget_init_endpoints(struct dwc3 *dwc, u8 total)
+{
+	u8				epnum;
+
+	INIT_LIST_HEAD(&dwc->gadget->ep_list);
+
+	for (epnum = 0; epnum < total; epnum++) {
+		int			ret;
+
+		ret = dwc3_gadget_init_endpoint(dwc, epnum);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void dwc3_gadget_free_endpoints(struct dwc3 *dwc)
+{
+	struct dwc3_ep			*dep;
+	u8				epnum;
+
+	for (epnum = 0; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
+		dep = dwc->eps[epnum];
+		if (!dep)
+			continue;
+		/*
+		 * Physical endpoints 0 and 1 are special; they form the
+		 * bi-directional USB endpoint 0.
+		 *
+		 * For those two physical endpoints, we don't allocate a TRB
+		 * pool nor do we add them the endpoints list. Due to that, we
+		 * shouldn't do these two operations otherwise we would end up
+		 * with all sorts of bugs when removing dwc3.ko.
+		 */
+		if (epnum != 0 && epnum != 1) {
+			dwc3_free_trb_pool(dep);
+			list_del(&dep->endpoint.ep_list);
+		}
+
+		dwc3_debugfs_remove_endpoint_dir(dep);
+		kfree(dep);
+	}
+}
+
+/* -------------------------------------------------------------------------- */
+
+static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep,
+		struct dwc3_request *req, struct dwc3_trb *trb,
+		const struct dwc3_event_depevt *event, int status, int chain)
+{
+	unsigned int		count;
+
+	dwc3_ep_inc_deq(dep);
+
+	trace_dwc3_complete_trb(dep, trb);
+	req->num_trbs--;
+
+	/*
+	 * If we're in the middle of series of chained TRBs and we
+	 * receive a short transfer along the way, DWC3 will skip
+	 * through all TRBs including the last TRB in the chain (the
+	 * where CHN bit is zero. DWC3 will also avoid clearing HWO
+	 * bit and SW has to do it manually.
+	 *
+	 * We're going to do that here to avoid problems of HW trying
+	 * to use bogus TRBs for transfers.
+	 */
+	if (chain && (trb->ctrl & DWC3_TRB_CTRL_HWO))
+		trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
+
+	/*
+	 * For isochronous transfers, the first TRB in a service interval must
+	 * have the Isoc-First type. Track and report its interval frame number.
+	 */
+	if (usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
+	    (trb->ctrl & DWC3_TRBCTL_ISOCHRONOUS_FIRST)) {
+		unsigned int frame_number;
+
+		frame_number = DWC3_TRB_CTRL_GET_SID_SOFN(trb->ctrl);
+		frame_number &= ~(dep->interval - 1);
+		req->request.frame_number = frame_number;
+	}
+
+	/*
+	 * We use bounce buffer for requests that needs extra TRB or OUT ZLP. If
+	 * this TRB points to the bounce buffer address, it's a MPS alignment
+	 * TRB. Don't add it to req->remaining calculation.
+	 */
+	if (trb->bpl == lower_32_bits(dep->dwc->bounce_addr) &&
+	    trb->bph == upper_32_bits(dep->dwc->bounce_addr)) {
+		trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
+		return 1;
+	}
+
+	count = trb->size & DWC3_TRB_SIZE_MASK;
+	req->remaining += count;
+
+	if ((trb->ctrl & DWC3_TRB_CTRL_HWO) && status != -ESHUTDOWN)
+		return 1;
+
+	if (event->status & DEPEVT_STATUS_SHORT && !chain)
+		return 1;
+
+	if ((trb->ctrl & DWC3_TRB_CTRL_ISP_IMI) &&
+	    DWC3_TRB_SIZE_TRBSTS(trb->size) == DWC3_TRBSTS_MISSED_ISOC)
+		return 1;
+
+	if ((trb->ctrl & DWC3_TRB_CTRL_IOC) ||
+	    (trb->ctrl & DWC3_TRB_CTRL_LST))
+		return 1;
+
+	return 0;
+}
+
+static int dwc3_gadget_ep_reclaim_trb_sg(struct dwc3_ep *dep,
+		struct dwc3_request *req, const struct dwc3_event_depevt *event,
+		int status)
+{
+	struct dwc3_trb *trb = &dep->trb_pool[dep->trb_dequeue];
+	struct scatterlist *sg = req->sg;
+	struct scatterlist *s;
+	unsigned int num_queued = req->num_queued_sgs;
+	unsigned int i;
+	int ret = 0;
+
+	for_each_sg(sg, s, num_queued, i) {
+		trb = &dep->trb_pool[dep->trb_dequeue];
+
+		req->sg = sg_next(s);
+		req->num_queued_sgs--;
+
+		ret = dwc3_gadget_ep_reclaim_completed_trb(dep, req,
+				trb, event, status, true);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
+static int dwc3_gadget_ep_reclaim_trb_linear(struct dwc3_ep *dep,
+		struct dwc3_request *req, const struct dwc3_event_depevt *event,
+		int status)
+{
+	struct dwc3_trb *trb = &dep->trb_pool[dep->trb_dequeue];
+
+	return dwc3_gadget_ep_reclaim_completed_trb(dep, req, trb,
+			event, status, false);
+}
+
+static bool dwc3_gadget_ep_request_completed(struct dwc3_request *req)
+{
+	return req->num_pending_sgs == 0 && req->num_queued_sgs == 0;
+}
+
+static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep,
+		const struct dwc3_event_depevt *event,
+		struct dwc3_request *req, int status)
+{
+	int request_status;
+	int ret;
+
+	if (req->request.num_mapped_sgs)
+		ret = dwc3_gadget_ep_reclaim_trb_sg(dep, req, event,
+				status);
+	else
+		ret = dwc3_gadget_ep_reclaim_trb_linear(dep, req, event,
+				status);
+
+	req->request.actual = req->request.length - req->remaining;
+
+	if (!dwc3_gadget_ep_request_completed(req))
+		goto out;
+
+	if (req->needs_extra_trb) {
+		ret = dwc3_gadget_ep_reclaim_trb_linear(dep, req, event,
+				status);
+		req->needs_extra_trb = false;
+	}
+
+	/*
+	 * The event status only reflects the status of the TRB with IOC set.
+	 * For the requests that don't set interrupt on completion, the driver
+	 * needs to check and return the status of the completed TRBs associated
+	 * with the request. Use the status of the last TRB of the request.
+	 */
+	if (req->request.no_interrupt) {
+		struct dwc3_trb *trb;
+
+		trb = dwc3_ep_prev_trb(dep, dep->trb_dequeue);
+		switch (DWC3_TRB_SIZE_TRBSTS(trb->size)) {
+		case DWC3_TRBSTS_MISSED_ISOC:
+			/* Isoc endpoint only */
+			request_status = -EXDEV;
+			break;
+		case DWC3_TRB_STS_XFER_IN_PROG:
+			/* Applicable when End Transfer with ForceRM=0 */
+		case DWC3_TRBSTS_SETUP_PENDING:
+			/* Control endpoint only */
+		case DWC3_TRBSTS_OK:
+		default:
+			request_status = 0;
+			break;
+		}
+	} else {
+		request_status = status;
+	}
+
+	dwc3_gadget_giveback(dep, req, request_status);
+
+out:
+	return ret;
+}
+
+static void dwc3_gadget_ep_cleanup_completed_requests(struct dwc3_ep *dep,
+		const struct dwc3_event_depevt *event, int status)
+{
+	struct dwc3_request	*req;
+
+	while (!list_empty(&dep->started_list)) {
+		int ret;
+
+		req = next_request(&dep->started_list);
+		ret = dwc3_gadget_ep_cleanup_completed_request(dep, event,
+				req, status);
+		if (ret)
+			break;
+		/*
+		 * The endpoint is disabled, let the dwc3_remove_requests()
+		 * handle the cleanup.
+		 */
+		if (!dep->endpoint.desc)
+			break;
+	}
+}
+
+static bool dwc3_gadget_ep_should_continue(struct dwc3_ep *dep)
+{
+	struct dwc3_request	*req;
+	struct dwc3		*dwc = dep->dwc;
+
+	if (!dep->endpoint.desc || !dwc->pullups_connected ||
+	    !dwc->connected)
+		return false;
+
+	if (!list_empty(&dep->pending_list))
+		return true;
+
+	/*
+	 * We only need to check the first entry of the started list. We can
+	 * assume the completed requests are removed from the started list.
+	 */
+	req = next_request(&dep->started_list);
+	if (!req)
+		return false;
+
+	return !dwc3_gadget_ep_request_completed(req);
+}
+
+static void dwc3_gadget_endpoint_frame_from_event(struct dwc3_ep *dep,
+		const struct dwc3_event_depevt *event)
+{
+	dep->frame_number = event->parameters;
+}
+
+static bool dwc3_gadget_endpoint_trbs_complete(struct dwc3_ep *dep,
+		const struct dwc3_event_depevt *event, int status)
+{
+	struct dwc3		*dwc = dep->dwc;
+	bool			no_started_trb = true;
+
+	dwc3_gadget_ep_cleanup_completed_requests(dep, event, status);
+
+	if (dep->flags & DWC3_EP_END_TRANSFER_PENDING)
+		goto out;
+
+	if (!dep->endpoint.desc)
+		return no_started_trb;
+
+	if (usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
+		list_empty(&dep->started_list) &&
+		(list_empty(&dep->pending_list) || status == -EXDEV))
+		dwc3_stop_active_transfer(dep, true, true);
+	else if (dwc3_gadget_ep_should_continue(dep))
+		if (__dwc3_gadget_kick_transfer(dep) == 0)
+			no_started_trb = false;
+
+out:
+	/*
+	 * WORKAROUND: This is the 2nd half of U1/U2 -> U0 workaround.
+	 * See dwc3_gadget_linksts_change_interrupt() for 1st half.
+	 */
+	if (DWC3_VER_IS_PRIOR(DWC3, 183A)) {
+		u32		reg;
+		int		i;
+
+		for (i = 0; i < DWC3_ENDPOINTS_NUM; i++) {
+			dep = dwc->eps[i];
+
+			if (!(dep->flags & DWC3_EP_ENABLED))
+				continue;
+
+			if (!list_empty(&dep->started_list))
+				return no_started_trb;
+		}
+
+		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+		reg |= dwc->u1u2;
+		dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+
+		dwc->u1u2 = 0;
+	}
+
+	return no_started_trb;
+}
+
+static void dwc3_gadget_endpoint_transfer_in_progress(struct dwc3_ep *dep,
+		const struct dwc3_event_depevt *event)
+{
+	int status = 0;
+
+	if (!dep->endpoint.desc)
+		return;
+
+	if (usb_endpoint_xfer_isoc(dep->endpoint.desc))
+		dwc3_gadget_endpoint_frame_from_event(dep, event);
+
+	if (event->status & DEPEVT_STATUS_BUSERR)
+		status = -ECONNRESET;
+
+	if (event->status & DEPEVT_STATUS_MISSED_ISOC)
+		status = -EXDEV;
+
+	dwc3_gadget_endpoint_trbs_complete(dep, event, status);
+}
+
+static void dwc3_gadget_endpoint_transfer_complete(struct dwc3_ep *dep,
+		const struct dwc3_event_depevt *event)
+{
+	int status = 0;
+
+	dep->flags &= ~DWC3_EP_TRANSFER_STARTED;
+
+	if (event->status & DEPEVT_STATUS_BUSERR)
+		status = -ECONNRESET;
+
+	if (dwc3_gadget_endpoint_trbs_complete(dep, event, status))
+		dep->flags &= ~DWC3_EP_WAIT_TRANSFER_COMPLETE;
+}
+
+static void dwc3_gadget_endpoint_transfer_not_ready(struct dwc3_ep *dep,
+		const struct dwc3_event_depevt *event)
+{
+	dwc3_gadget_endpoint_frame_from_event(dep, event);
+
+	/*
+	 * The XferNotReady event is generated only once before the endpoint
+	 * starts. It will be generated again when END_TRANSFER command is
+	 * issued. For some controller versions, the XferNotReady event may be
+	 * generated while the END_TRANSFER command is still in process. Ignore
+	 * it and wait for the next XferNotReady event after the command is
+	 * completed.
+	 */
+	if (dep->flags & DWC3_EP_END_TRANSFER_PENDING)
+		return;
+
+	(void) __dwc3_gadget_start_isoc(dep);
+}
+
+static void dwc3_gadget_endpoint_command_complete(struct dwc3_ep *dep,
+		const struct dwc3_event_depevt *event)
+{
+	u8 cmd = DEPEVT_PARAMETER_CMD(event->parameters);
+
+	if (cmd != DWC3_DEPCMD_ENDTRANSFER)
+		return;
+
+	/*
+	 * The END_TRANSFER command will cause the controller to generate a
+	 * NoStream Event, and it's not due to the host DP NoStream rejection.
+	 * Ignore the next NoStream event.
+	 */
+	if (dep->stream_capable)
+		dep->flags |= DWC3_EP_IGNORE_NEXT_NOSTREAM;
+
+	dep->flags &= ~DWC3_EP_END_TRANSFER_PENDING;
+	dep->flags &= ~DWC3_EP_TRANSFER_STARTED;
+	dwc3_gadget_ep_cleanup_cancelled_requests(dep);
+
+	if (dep->flags & DWC3_EP_PENDING_CLEAR_STALL) {
+		struct dwc3 *dwc = dep->dwc;
+
+		dep->flags &= ~DWC3_EP_PENDING_CLEAR_STALL;
+		if (dwc3_send_clear_stall_ep_cmd(dep)) {
+			struct usb_ep *ep0 = &dwc->eps[0]->endpoint;
+
+			dev_err(dwc->dev, "failed to clear STALL on %s\n", dep->name);
+			if (dwc->delayed_status)
+				__dwc3_gadget_ep0_set_halt(ep0, 1);
+			return;
+		}
+
+		dep->flags &= ~(DWC3_EP_STALL | DWC3_EP_WEDGE);
+		if (dwc->clear_stall_protocol == dep->number)
+			dwc3_ep0_send_delayed_status(dwc);
+	}
+
+	if ((dep->flags & DWC3_EP_DELAY_START) &&
+	    !usb_endpoint_xfer_isoc(dep->endpoint.desc))
+		__dwc3_gadget_kick_transfer(dep);
+
+	dep->flags &= ~DWC3_EP_DELAY_START;
+}
+
+static void dwc3_gadget_endpoint_stream_event(struct dwc3_ep *dep,
+		const struct dwc3_event_depevt *event)
+{
+	struct dwc3 *dwc = dep->dwc;
+
+	if (event->status == DEPEVT_STREAMEVT_FOUND) {
+		dep->flags |= DWC3_EP_FIRST_STREAM_PRIMED;
+		goto out;
+	}
+
+	/* Note: NoStream rejection event param value is 0 and not 0xFFFF */
+	switch (event->parameters) {
+	case DEPEVT_STREAM_PRIME:
+		/*
+		 * If the host can properly transition the endpoint state from
+		 * idle to prime after a NoStream rejection, there's no need to
+		 * force restarting the endpoint to reinitiate the stream. To
+		 * simplify the check, assume the host follows the USB spec if
+		 * it primed the endpoint more than once.
+		 */
+		if (dep->flags & DWC3_EP_FORCE_RESTART_STREAM) {
+			if (dep->flags & DWC3_EP_FIRST_STREAM_PRIMED)
+				dep->flags &= ~DWC3_EP_FORCE_RESTART_STREAM;
+			else
+				dep->flags |= DWC3_EP_FIRST_STREAM_PRIMED;
+		}
+
+		break;
+	case DEPEVT_STREAM_NOSTREAM:
+		if ((dep->flags & DWC3_EP_IGNORE_NEXT_NOSTREAM) ||
+		    !(dep->flags & DWC3_EP_FORCE_RESTART_STREAM) ||
+		    (!DWC3_MST_CAPABLE(&dwc->hwparams) &&
+		     !(dep->flags & DWC3_EP_WAIT_TRANSFER_COMPLETE)))
+			break;
+
+		/*
+		 * If the host rejects a stream due to no active stream, by the
+		 * USB and xHCI spec, the endpoint will be put back to idle
+		 * state. When the host is ready (buffer added/updated), it will
+		 * prime the endpoint to inform the usb device controller. This
+		 * triggers the device controller to issue ERDY to restart the
+		 * stream. However, some hosts don't follow this and keep the
+		 * endpoint in the idle state. No prime will come despite host
+		 * streams are updated, and the device controller will not be
+		 * triggered to generate ERDY to move the next stream data. To
+		 * workaround this and maintain compatibility with various
+		 * hosts, force to reinitiate the stream until the host is ready
+		 * instead of waiting for the host to prime the endpoint.
+		 */
+		if (DWC3_VER_IS_WITHIN(DWC32, 100A, ANY)) {
+			unsigned int cmd = DWC3_DGCMD_SET_ENDPOINT_PRIME;
+
+			dwc3_send_gadget_generic_command(dwc, cmd, dep->number);
+		} else {
+			dep->flags |= DWC3_EP_DELAY_START;
+			dwc3_stop_active_transfer(dep, true, true);
+			return;
+		}
+		break;
+	}
+
+out:
+	dep->flags &= ~DWC3_EP_IGNORE_NEXT_NOSTREAM;
+}
+
+static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
+		const struct dwc3_event_depevt *event)
+{
+	struct dwc3_ep		*dep;
+	u8			epnum = event->endpoint_number;
+
+	dep = dwc->eps[epnum];
+
+	if (!(dep->flags & DWC3_EP_ENABLED)) {
+		if ((epnum > 1) && !(dep->flags & DWC3_EP_TRANSFER_STARTED))
+			return;
+
+		/* Handle only EPCMDCMPLT when EP disabled */
+		if ((event->endpoint_event != DWC3_DEPEVT_EPCMDCMPLT) &&
+			!(epnum <= 1 && event->endpoint_event == DWC3_DEPEVT_XFERCOMPLETE))
+			return;
+	}
+
+	if (epnum == 0 || epnum == 1) {
+		dwc3_ep0_interrupt(dwc, event);
+		return;
+	}
+
+	switch (event->endpoint_event) {
+	case DWC3_DEPEVT_XFERINPROGRESS:
+		dwc3_gadget_endpoint_transfer_in_progress(dep, event);
+		break;
+	case DWC3_DEPEVT_XFERNOTREADY:
+		dwc3_gadget_endpoint_transfer_not_ready(dep, event);
+		break;
+	case DWC3_DEPEVT_EPCMDCMPLT:
+		dwc3_gadget_endpoint_command_complete(dep, event);
+		break;
+	case DWC3_DEPEVT_XFERCOMPLETE:
+		dwc3_gadget_endpoint_transfer_complete(dep, event);
+		break;
+	case DWC3_DEPEVT_STREAMEVT:
+		dwc3_gadget_endpoint_stream_event(dep, event);
+		break;
+	case DWC3_DEPEVT_RXTXFIFOEVT:
+		break;
+	default:
+		dev_err(dwc->dev, "unknown endpoint event %d\n", event->endpoint_event);
+		break;
+	}
+}
+
+static void dwc3_disconnect_gadget(struct dwc3 *dwc)
+{
+	if (dwc->async_callbacks && dwc->gadget_driver->disconnect) {
+		spin_unlock(&dwc->lock);
+		dwc->gadget_driver->disconnect(dwc->gadget);
+		spin_lock(&dwc->lock);
+	}
+}
+
+static void dwc3_suspend_gadget(struct dwc3 *dwc)
+{
+	if (dwc->async_callbacks && dwc->gadget_driver->suspend) {
+		spin_unlock(&dwc->lock);
+		dwc->gadget_driver->suspend(dwc->gadget);
+		spin_lock(&dwc->lock);
+	}
+}
+
+static void dwc3_resume_gadget(struct dwc3 *dwc)
+{
+	if (dwc->async_callbacks && dwc->gadget_driver->resume) {
+		spin_unlock(&dwc->lock);
+		dwc->gadget_driver->resume(dwc->gadget);
+		spin_lock(&dwc->lock);
+	}
+}
+
+static void dwc3_reset_gadget(struct dwc3 *dwc)
+{
+	if (!dwc->gadget_driver)
+		return;
+
+	if (dwc->async_callbacks && dwc->gadget->speed != USB_SPEED_UNKNOWN) {
+		spin_unlock(&dwc->lock);
+		usb_gadget_udc_reset(dwc->gadget, dwc->gadget_driver);
+		spin_lock(&dwc->lock);
+	}
+}
+
+void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force,
+	bool interrupt)
+{
+	struct dwc3 *dwc = dep->dwc;
+
+	/*
+	 * Only issue End Transfer command to the control endpoint of a started
+	 * Data Phase. Typically we should only do so in error cases such as
+	 * invalid/unexpected direction as described in the control transfer
+	 * flow of the programming guide.
+	 */
+	if (dep->number <= 1 && dwc->ep0state != EP0_DATA_PHASE)
+		return;
+
+	if (interrupt && (dep->flags & DWC3_EP_DELAY_STOP))
+		return;
+
+	if (!(dep->flags & DWC3_EP_TRANSFER_STARTED) ||
+	    (dep->flags & DWC3_EP_END_TRANSFER_PENDING))
+		return;
+
+	/*
+	 * If a Setup packet is received but yet to DMA out, the controller will
+	 * not process the End Transfer command of any endpoint. Polling of its
+	 * DEPCMD.CmdAct may block setting up TRB for Setup packet, causing a
+	 * timeout. Delay issuing the End Transfer command until the Setup TRB is
+	 * prepared.
+	 */
+	if (dwc->ep0state != EP0_SETUP_PHASE && !dwc->delayed_status) {
+		dep->flags |= DWC3_EP_DELAY_STOP;
+		return;
+	}
+
+	/*
+	 * NOTICE: We are violating what the Databook says about the
+	 * EndTransfer command. Ideally we would _always_ wait for the
+	 * EndTransfer Command Completion IRQ, but that's causing too
+	 * much trouble synchronizing between us and gadget driver.
+	 *
+	 * We have discussed this with the IP Provider and it was
+	 * suggested to giveback all requests here.
+	 *
+	 * Note also that a similar handling was tested by Synopsys
+	 * (thanks a lot Paul) and nothing bad has come out of it.
+	 * In short, what we're doing is issuing EndTransfer with
+	 * CMDIOC bit set and delay kicking transfer until the
+	 * EndTransfer command had completed.
+	 *
+	 * As of IP version 3.10a of the DWC_usb3 IP, the controller
+	 * supports a mode to work around the above limitation. The
+	 * software can poll the CMDACT bit in the DEPCMD register
+	 * after issuing a EndTransfer command. This mode is enabled
+	 * by writing GUCTL2[14]. This polling is already done in the
+	 * dwc3_send_gadget_ep_cmd() function so if the mode is
+	 * enabled, the EndTransfer command will have completed upon
+	 * returning from this function.
+	 *
+	 * This mode is NOT available on the DWC_usb31 IP.  In this
+	 * case, if the IOC bit is not set, then delay by 1ms
+	 * after issuing the EndTransfer command.  This allows for the
+	 * controller to handle the command completely before DWC3
+	 * remove requests attempts to unmap USB request buffers.
+	 */
+
+	__dwc3_stop_active_transfer(dep, force, interrupt);
+}
+
+static void dwc3_clear_stall_all_ep(struct dwc3 *dwc)
+{
+	u32 epnum;
+
+	for (epnum = 1; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
+		struct dwc3_ep *dep;
+		int ret;
+
+		dep = dwc->eps[epnum];
+		if (!dep)
+			continue;
+
+		if (!(dep->flags & DWC3_EP_STALL))
+			continue;
+
+		dep->flags &= ~DWC3_EP_STALL;
+
+		ret = dwc3_send_clear_stall_ep_cmd(dep);
+		WARN_ON_ONCE(ret);
+	}
+}
+
+static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
+{
+	int			reg;
+
+	dwc->suspended = false;
+
+	dwc3_gadget_set_link_state(dwc, DWC3_LINK_STATE_RX_DET);
+
+	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+	reg &= ~DWC3_DCTL_INITU1ENA;
+	reg &= ~DWC3_DCTL_INITU2ENA;
+	dwc3_gadget_dctl_write_safe(dwc, reg);
+
+	dwc->connected = false;
+
+	dwc3_disconnect_gadget(dwc);
+
+	dwc->gadget->speed = USB_SPEED_UNKNOWN;
+	dwc->setup_packet_pending = false;
+	dwc->gadget->wakeup_armed = false;
+	dwc3_gadget_enable_linksts_evts(dwc, false);
+	usb_gadget_set_state(dwc->gadget, USB_STATE_NOTATTACHED);
+
+	dwc3_ep0_reset_state(dwc);
+
+	/*
+	 * Request PM idle to address condition where usage count is
+	 * already decremented to zero, but waiting for the disconnect
+	 * interrupt to set dwc->connected to FALSE.
+	 */
+	pm_request_idle(dwc->dev);
+}
+
+static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
+{
+	u32			reg;
+
+	dwc->suspended = false;
+
+	/*
+	 * Ideally, dwc3_reset_gadget() would trigger the function
+	 * drivers to stop any active transfers through ep disable.
+	 * However, for functions which defer ep disable, such as mass
+	 * storage, we will need to rely on the call to stop active
+	 * transfers here, and avoid allowing of request queuing.
+	 */
+	dwc->connected = false;
+
+	/*
+	 * WORKAROUND: DWC3 revisions <1.88a have an issue which
+	 * would cause a missing Disconnect Event if there's a
+	 * pending Setup Packet in the FIFO.
+	 *
+	 * There's no suggested workaround on the official Bug
+	 * report, which states that "unless the driver/application
+	 * is doing any special handling of a disconnect event,
+	 * there is no functional issue".
+	 *
+	 * Unfortunately, it turns out that we _do_ some special
+	 * handling of a disconnect event, namely complete all
+	 * pending transfers, notify gadget driver of the
+	 * disconnection, and so on.
+	 *
+	 * Our suggested workaround is to follow the Disconnect
+	 * Event steps here, instead, based on a setup_packet_pending
+	 * flag. Such flag gets set whenever we have a SETUP_PENDING
+	 * status for EP0 TRBs and gets cleared on XferComplete for the
+	 * same endpoint.
+	 *
+	 * Refers to:
+	 *
+	 * STAR#9000466709: RTL: Device : Disconnect event not
+	 * generated if setup packet pending in FIFO
+	 */
+	if (DWC3_VER_IS_PRIOR(DWC3, 188A)) {
+		if (dwc->setup_packet_pending)
+			dwc3_gadget_disconnect_interrupt(dwc);
+	}
+
+	dwc3_reset_gadget(dwc);
+
+	/*
+	 * From SNPS databook section 8.1.2, the EP0 should be in setup
+	 * phase. So ensure that EP0 is in setup phase by issuing a stall
+	 * and restart if EP0 is not in setup phase.
+	 */
+	dwc3_ep0_reset_state(dwc);
+
+	/*
+	 * In the Synopsis DesignWare Cores USB3 Databook Rev. 3.30a
+	 * Section 4.1.2 Table 4-2, it states that during a USB reset, the SW
+	 * needs to ensure that it sends "a DEPENDXFER command for any active
+	 * transfers."
+	 */
+	dwc3_stop_active_transfers(dwc);
+	dwc->connected = true;
+
+	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+	reg &= ~DWC3_DCTL_TSTCTRL_MASK;
+	dwc3_gadget_dctl_write_safe(dwc, reg);
+	dwc->test_mode = false;
+	dwc->gadget->wakeup_armed = false;
+	dwc3_gadget_enable_linksts_evts(dwc, false);
+	dwc3_clear_stall_all_ep(dwc);
+
+	/* Reset device address to zero */
+	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+	reg &= ~(DWC3_DCFG_DEVADDR_MASK);
+	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+}
+
+static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)
+{
+	struct dwc3_ep		*dep;
+	int			ret;
+	u32			reg;
+	u8			lanes = 1;
+	u8			speed;
+
+	if (!dwc->softconnect)
+		return;
+
+	reg = dwc3_readl(dwc->regs, DWC3_DSTS);
+	speed = reg & DWC3_DSTS_CONNECTSPD;
+	dwc->speed = speed;
+
+	if (DWC3_IP_IS(DWC32))
+		lanes = DWC3_DSTS_CONNLANES(reg) + 1;
+
+	dwc->gadget->ssp_rate = USB_SSP_GEN_UNKNOWN;
+
+	/*
+	 * RAMClkSel is reset to 0 after USB reset, so it must be reprogrammed
+	 * each time on Connect Done.
+	 *
+	 * Currently we always use the reset value. If any platform
+	 * wants to set this to a different value, we need to add a
+	 * setting and update GCTL.RAMCLKSEL here.
+	 */
+
+	switch (speed) {
+	case DWC3_DSTS_SUPERSPEED_PLUS:
+		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
+		dwc->gadget->ep0->maxpacket = 512;
+		dwc->gadget->speed = USB_SPEED_SUPER_PLUS;
+
+		if (lanes > 1)
+			dwc->gadget->ssp_rate = USB_SSP_GEN_2x2;
+		else
+			dwc->gadget->ssp_rate = USB_SSP_GEN_2x1;
+		break;
+	case DWC3_DSTS_SUPERSPEED:
+		/*
+		 * WORKAROUND: DWC3 revisions <1.90a have an issue which
+		 * would cause a missing USB3 Reset event.
+		 *
+		 * In such situations, we should force a USB3 Reset
+		 * event by calling our dwc3_gadget_reset_interrupt()
+		 * routine.
+		 *
+		 * Refers to:
+		 *
+		 * STAR#9000483510: RTL: SS : USB3 reset event may
+		 * not be generated always when the link enters poll
+		 */
+		if (DWC3_VER_IS_PRIOR(DWC3, 190A))
+			dwc3_gadget_reset_interrupt(dwc);
+
+		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
+		dwc->gadget->ep0->maxpacket = 512;
+		dwc->gadget->speed = USB_SPEED_SUPER;
+
+		if (lanes > 1) {
+			dwc->gadget->speed = USB_SPEED_SUPER_PLUS;
+			dwc->gadget->ssp_rate = USB_SSP_GEN_1x2;
+		}
+		break;
+	case DWC3_DSTS_HIGHSPEED:
+		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(64);
+		dwc->gadget->ep0->maxpacket = 64;
+		dwc->gadget->speed = USB_SPEED_HIGH;
+		break;
+	case DWC3_DSTS_FULLSPEED:
+		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(64);
+		dwc->gadget->ep0->maxpacket = 64;
+		dwc->gadget->speed = USB_SPEED_FULL;
+		break;
+	}
+
+	dwc->eps[1]->endpoint.maxpacket = dwc->gadget->ep0->maxpacket;
+
+	/* Enable USB2 LPM Capability */
+
+	if (!DWC3_VER_IS_WITHIN(DWC3, ANY, 194A) &&
+	    !dwc->usb2_gadget_lpm_disable &&
+	    (speed != DWC3_DSTS_SUPERSPEED) &&
+	    (speed != DWC3_DSTS_SUPERSPEED_PLUS)) {
+		reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+		reg |= DWC3_DCFG_LPM_CAP;
+		dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+
+		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+		reg &= ~(DWC3_DCTL_HIRD_THRES_MASK | DWC3_DCTL_L1_HIBER_EN);
+
+		reg |= DWC3_DCTL_HIRD_THRES(dwc->hird_threshold |
+					    (dwc->is_utmi_l1_suspend << 4));
+
+		/*
+		 * When dwc3 revisions >= 2.40a, LPM Erratum is enabled and
+		 * DCFG.LPMCap is set, core responses with an ACK and the
+		 * BESL value in the LPM token is less than or equal to LPM
+		 * NYET threshold.
+		 */
+		WARN_ONCE(DWC3_VER_IS_PRIOR(DWC3, 240A) && dwc->has_lpm_erratum,
+				"LPM Erratum not available on dwc3 revisions < 2.40a\n");
+
+		if (dwc->has_lpm_erratum && !DWC3_VER_IS_PRIOR(DWC3, 240A))
+			reg |= DWC3_DCTL_NYET_THRES(dwc->lpm_nyet_threshold);
+
+		dwc3_gadget_dctl_write_safe(dwc, reg);
+	} else {
+		if (dwc->usb2_gadget_lpm_disable) {
+			reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+			reg &= ~DWC3_DCFG_LPM_CAP;
+			dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+		}
+
+		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+		reg &= ~DWC3_DCTL_HIRD_THRES_MASK;
+		dwc3_gadget_dctl_write_safe(dwc, reg);
+	}
+
+	dep = dwc->eps[0];
+	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_MODIFY);
+	if (ret) {
+		dev_err(dwc->dev, "failed to enable %s\n", dep->name);
+		return;
+	}
+
+	dep = dwc->eps[1];
+	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_MODIFY);
+	if (ret) {
+		dev_err(dwc->dev, "failed to enable %s\n", dep->name);
+		return;
+	}
+
+	/*
+	 * Configure PHY via GUSB3PIPECTLn if required.
+	 *
+	 * Update GTXFIFOSIZn
+	 *
+	 * In both cases reset values should be sufficient.
+	 */
+}
+
+static void dwc3_gadget_wakeup_interrupt(struct dwc3 *dwc, unsigned int evtinfo)
+{
+	dwc->suspended = false;
+
+	/*
+	 * TODO take core out of low power mode when that's
+	 * implemented.
+	 */
+
+	if (dwc->async_callbacks && dwc->gadget_driver->resume) {
+		spin_unlock(&dwc->lock);
+		dwc->gadget_driver->resume(dwc->gadget);
+		spin_lock(&dwc->lock);
+	}
+
+	dwc->link_state = evtinfo & DWC3_LINK_STATE_MASK;
+}
+
+static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc,
+		unsigned int evtinfo)
+{
+	enum dwc3_link_state	next = evtinfo & DWC3_LINK_STATE_MASK;
+	unsigned int		pwropt;
+
+	/*
+	 * WORKAROUND: DWC3 < 2.50a have an issue when configured without
+	 * Hibernation mode enabled which would show up when device detects
+	 * host-initiated U3 exit.
+	 *
+	 * In that case, device will generate a Link State Change Interrupt
+	 * from U3 to RESUME which is only necessary if Hibernation is
+	 * configured in.
+	 *
+	 * There are no functional changes due to such spurious event and we
+	 * just need to ignore it.
+	 *
+	 * Refers to:
+	 *
+	 * STAR#9000570034 RTL: SS Resume event generated in non-Hibernation
+	 * operational mode
+	 */
+	pwropt = DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams1);
+	if (DWC3_VER_IS_PRIOR(DWC3, 250A) &&
+			(pwropt != DWC3_GHWPARAMS1_EN_PWROPT_HIB)) {
+		if ((dwc->link_state == DWC3_LINK_STATE_U3) &&
+				(next == DWC3_LINK_STATE_RESUME)) {
+			return;
+		}
+	}
+
+	/*
+	 * WORKAROUND: DWC3 Revisions <1.83a have an issue which, depending
+	 * on the link partner, the USB session might do multiple entry/exit
+	 * of low power states before a transfer takes place.
+	 *
+	 * Due to this problem, we might experience lower throughput. The
+	 * suggested workaround is to disable DCTL[12:9] bits if we're
+	 * transitioning from U1/U2 to U0 and enable those bits again
+	 * after a transfer completes and there are no pending transfers
+	 * on any of the enabled endpoints.
+	 *
+	 * This is the first half of that workaround.
+	 *
+	 * Refers to:
+	 *
+	 * STAR#9000446952: RTL: Device SS : if U1/U2 ->U0 takes >128us
+	 * core send LGO_Ux entering U0
+	 */
+	if (DWC3_VER_IS_PRIOR(DWC3, 183A)) {
+		if (next == DWC3_LINK_STATE_U0) {
+			u32	u1u2;
+			u32	reg;
+
+			switch (dwc->link_state) {
+			case DWC3_LINK_STATE_U1:
+			case DWC3_LINK_STATE_U2:
+				reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+				u1u2 = reg & (DWC3_DCTL_INITU2ENA
+						| DWC3_DCTL_ACCEPTU2ENA
+						| DWC3_DCTL_INITU1ENA
+						| DWC3_DCTL_ACCEPTU1ENA);
+
+				if (!dwc->u1u2)
+					dwc->u1u2 = reg & u1u2;
+
+				reg &= ~u1u2;
+
+				dwc3_gadget_dctl_write_safe(dwc, reg);
+				break;
+			default:
+				/* do nothing */
+				break;
+			}
+		}
+	}
+
+	switch (next) {
+	case DWC3_LINK_STATE_U0:
+		if (dwc->gadget->wakeup_armed) {
+			dwc3_gadget_enable_linksts_evts(dwc, false);
+			dwc3_resume_gadget(dwc);
+			dwc->suspended = false;
+		}
+		break;
+	case DWC3_LINK_STATE_U1:
+		if (dwc->speed == USB_SPEED_SUPER)
+			dwc3_suspend_gadget(dwc);
+		break;
+	case DWC3_LINK_STATE_U2:
+	case DWC3_LINK_STATE_U3:
+		dwc3_suspend_gadget(dwc);
+		break;
+	case DWC3_LINK_STATE_RESUME:
+		dwc3_resume_gadget(dwc);
+		break;
+	default:
+		/* do nothing */
+		break;
+	}
+
+	dwc->link_state = next;
+}
+
+static void dwc3_gadget_suspend_interrupt(struct dwc3 *dwc,
+					  unsigned int evtinfo)
+{
+	enum dwc3_link_state next = evtinfo & DWC3_LINK_STATE_MASK;
+
+	if (!dwc->suspended && next == DWC3_LINK_STATE_U3) {
+		dwc->suspended = true;
+		dwc3_suspend_gadget(dwc);
+	}
+
+	dwc->link_state = next;
+}
+
+static void dwc3_gadget_interrupt(struct dwc3 *dwc,
+		const struct dwc3_event_devt *event)
+{
+	switch (event->type) {
+	case DWC3_DEVICE_EVENT_DISCONNECT:
+		dwc3_gadget_disconnect_interrupt(dwc);
+		break;
+	case DWC3_DEVICE_EVENT_RESET:
+		dwc3_gadget_reset_interrupt(dwc);
+		break;
+	case DWC3_DEVICE_EVENT_CONNECT_DONE:
+		dwc3_gadget_conndone_interrupt(dwc);
+		break;
+	case DWC3_DEVICE_EVENT_WAKEUP:
+		dwc3_gadget_wakeup_interrupt(dwc, event->event_info);
+		break;
+	case DWC3_DEVICE_EVENT_HIBER_REQ:
+		dev_WARN_ONCE(dwc->dev, true, "unexpected hibernation event\n");
+		break;
+	case DWC3_DEVICE_EVENT_LINK_STATUS_CHANGE:
+		dwc3_gadget_linksts_change_interrupt(dwc, event->event_info);
+		break;
+	case DWC3_DEVICE_EVENT_SUSPEND:
+		/* It changed to be suspend event for version 2.30a and above */
+		if (!DWC3_VER_IS_PRIOR(DWC3, 230A))
+			dwc3_gadget_suspend_interrupt(dwc, event->event_info);
+		break;
+	case DWC3_DEVICE_EVENT_SOF:
+	case DWC3_DEVICE_EVENT_ERRATIC_ERROR:
+	case DWC3_DEVICE_EVENT_CMD_CMPL:
+	case DWC3_DEVICE_EVENT_OVERFLOW:
+		break;
+	default:
+		dev_WARN(dwc->dev, "UNKNOWN IRQ %d\n", event->type);
+	}
+}
+
+static void dwc3_process_event_entry(struct dwc3 *dwc,
+		const union dwc3_event *event)
+{
+	trace_dwc3_event(event->raw, dwc);
+
+	if (!event->type.is_devspec)
+		dwc3_endpoint_interrupt(dwc, &event->depevt);
+	else if (event->type.type == DWC3_EVENT_TYPE_DEV)
+		dwc3_gadget_interrupt(dwc, &event->devt);
+	else
+		dev_err(dwc->dev, "UNKNOWN IRQ type %d\n", event->raw);
+}
+
+static irqreturn_t dwc3_process_event_buf(struct dwc3_event_buffer *evt)
+{
+	struct dwc3 *dwc = evt->dwc;
+	irqreturn_t ret = IRQ_NONE;
+	int left;
+
+	left = evt->count;
+
+	if (!(evt->flags & DWC3_EVENT_PENDING))
+		return IRQ_NONE;
+
+	while (left > 0) {
+		union dwc3_event event;
+
+		event.raw = *(u32 *) (evt->cache + evt->lpos);
+
+		dwc3_process_event_entry(dwc, &event);
+
+		/*
+		 * FIXME we wrap around correctly to the next entry as
+		 * almost all entries are 4 bytes in size. There is one
+		 * entry which has 12 bytes which is a regular entry
+		 * followed by 8 bytes data. ATM I don't know how
+		 * things are organized if we get next to the a
+		 * boundary so I worry about that once we try to handle
+		 * that.
+		 */
+		evt->lpos = (evt->lpos + 4) % evt->length;
+		left -= 4;
+	}
+
+	evt->count = 0;
+	ret = IRQ_HANDLED;
+
+	/* Unmask interrupt */
+	dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0),
+		    DWC3_GEVNTSIZ_SIZE(evt->length));
+
+	if (dwc->imod_interval) {
+		dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), DWC3_GEVNTCOUNT_EHB);
+		dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), dwc->imod_interval);
+	}
+
+	/* Keep the clearing of DWC3_EVENT_PENDING at the end */
+	evt->flags &= ~DWC3_EVENT_PENDING;
+
+	return ret;
+}
+
+static irqreturn_t dwc3_thread_interrupt(int irq, void *_evt)
+{
+	struct dwc3_event_buffer *evt = _evt;
+	struct dwc3 *dwc = evt->dwc;
+	unsigned long flags;
+	irqreturn_t ret = IRQ_NONE;
+
+	local_bh_disable();
+	spin_lock_irqsave(&dwc->lock, flags);
+	ret = dwc3_process_event_buf(evt);
+	spin_unlock_irqrestore(&dwc->lock, flags);
+	local_bh_enable();
+
+	return ret;
+}
+
+static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt)
+{
+	struct dwc3 *dwc = evt->dwc;
+	u32 amount;
+	u32 count;
+
+	if (pm_runtime_suspended(dwc->dev)) {
+		dwc->pending_events = true;
+		/*
+		 * Trigger runtime resume. The get() function will be balanced
+		 * after processing the pending events in dwc3_process_pending
+		 * events().
+		 */
+		pm_runtime_get(dwc->dev);
+		disable_irq_nosync(dwc->irq_gadget);
+		return IRQ_HANDLED;
+	}
+
+	/*
+	 * With PCIe legacy interrupt, test shows that top-half irq handler can
+	 * be called again after HW interrupt deassertion. Check if bottom-half
+	 * irq event handler completes before caching new event to prevent
+	 * losing events.
+	 */
+	if (evt->flags & DWC3_EVENT_PENDING)
+		return IRQ_HANDLED;
+
+	count = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0));
+	count &= DWC3_GEVNTCOUNT_MASK;
+	if (!count)
+		return IRQ_NONE;
+
+	evt->count = count;
+	evt->flags |= DWC3_EVENT_PENDING;
+
+	/* Mask interrupt */
+	dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0),
+		    DWC3_GEVNTSIZ_INTMASK | DWC3_GEVNTSIZ_SIZE(evt->length));
+
+	amount = min(count, evt->length - evt->lpos);
+	memcpy(evt->cache + evt->lpos, evt->buf + evt->lpos, amount);
+
+	if (amount < count)
+		memcpy(evt->cache, evt->buf, count - amount);
+
+	dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), count);
+
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t dwc3_interrupt(int irq, void *_evt)
+{
+	struct dwc3_event_buffer	*evt = _evt;
+
+	return dwc3_check_event_buf(evt);
+}
+
+static int dwc3_gadget_get_irq(struct dwc3 *dwc)
+{
+	struct platform_device *dwc3_pdev = to_platform_device(dwc->dev);
+	int irq;
+
+	irq = platform_get_irq_byname_optional(dwc3_pdev, "peripheral");
+	if (irq > 0)
+		goto out;
+
+	if (irq == -EPROBE_DEFER)
+		goto out;
+
+	irq = platform_get_irq_byname_optional(dwc3_pdev, "dwc_usb3");
+	if (irq > 0)
+		goto out;
+
+	if (irq == -EPROBE_DEFER)
+		goto out;
+
+	irq = platform_get_irq(dwc3_pdev, 0);
+
+out:
+	return irq;
+}
+
+static void dwc_gadget_release(struct device *dev)
+{
+	struct usb_gadget *gadget = container_of(dev, struct usb_gadget, dev);
+
+	kfree(gadget);
+}
+
+/**
+ * dwc3_gadget_init - initializes gadget related registers
+ * @dwc: pointer to our controller context structure
+ *
+ * Returns 0 on success otherwise negative errno.
+ */
+int dwc3_gadget_init(struct dwc3 *dwc)
+{
+	int ret;
+	int irq;
+	struct device *dev;
+
+	irq = dwc3_gadget_get_irq(dwc);
+	if (irq < 0) {
+		ret = irq;
+		goto err0;
+	}
+
+	dwc->irq_gadget = irq;
+
+	dwc->ep0_trb = dma_alloc_coherent(dwc->sysdev,
+					  sizeof(*dwc->ep0_trb) * 2,
+					  &dwc->ep0_trb_addr, GFP_KERNEL);
+	if (!dwc->ep0_trb) {
+		dev_err(dwc->dev, "failed to allocate ep0 trb\n");
+		ret = -ENOMEM;
+		goto err0;
+	}
+
+	dwc->setup_buf = kzalloc(DWC3_EP0_SETUP_SIZE, GFP_KERNEL);
+	if (!dwc->setup_buf) {
+		ret = -ENOMEM;
+		goto err1;
+	}
+
+	dwc->bounce = dma_alloc_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE,
+			&dwc->bounce_addr, GFP_KERNEL);
+	if (!dwc->bounce) {
+		ret = -ENOMEM;
+		goto err2;
+	}
+
+	init_completion(&dwc->ep0_in_setup);
+	dwc->gadget = kzalloc(sizeof(struct usb_gadget), GFP_KERNEL);
+	if (!dwc->gadget) {
+		ret = -ENOMEM;
+		goto err3;
+	}
+
+
+	usb_initialize_gadget(dwc->dev, dwc->gadget, dwc_gadget_release);
+	dev				= &dwc->gadget->dev;
+	dev->platform_data		= dwc;
+	dwc->gadget->ops		= &dwc3_gadget_ops;
+	dwc->gadget->speed		= USB_SPEED_UNKNOWN;
+	dwc->gadget->ssp_rate		= USB_SSP_GEN_UNKNOWN;
+	dwc->gadget->sg_supported	= true;
+	dwc->gadget->name		= "dwc3-gadget";
+	dwc->gadget->lpm_capable	= !dwc->usb2_gadget_lpm_disable;
+	dwc->gadget->wakeup_capable	= true;
+
+	/*
+	 * FIXME We might be setting max_speed to <SUPER, however versions
+	 * <2.20a of dwc3 have an issue with metastability (documented
+	 * elsewhere in this driver) which tells us we can't set max speed to
+	 * anything lower than SUPER.
+	 *
+	 * Because gadget.max_speed is only used by composite.c and function
+	 * drivers (i.e. it won't go into dwc3's registers) we are allowing this
+	 * to happen so we avoid sending SuperSpeed Capability descriptor
+	 * together with our BOS descriptor as that could confuse host into
+	 * thinking we can handle super speed.
+	 *
+	 * Note that, in fact, we won't even support GetBOS requests when speed
+	 * is less than super speed because we don't have means, yet, to tell
+	 * composite.c that we are USB 2.0 + LPM ECN.
+	 */
+	if (DWC3_VER_IS_PRIOR(DWC3, 220A) &&
+	    !dwc->dis_metastability_quirk)
+		dev_info(dwc->dev, "changing max_speed on rev %08x\n",
+				dwc->revision);
+
+	dwc->gadget->max_speed		= dwc->maximum_speed;
+	dwc->gadget->max_ssp_rate	= dwc->max_ssp_rate;
+
+	/*
+	 * REVISIT: Here we should clear all pending IRQs to be
+	 * sure we're starting from a well known location.
+	 */
+
+	ret = dwc3_gadget_init_endpoints(dwc, dwc->num_eps);
+	if (ret)
+		goto err4;
+
+	ret = usb_add_gadget(dwc->gadget);
+	if (ret) {
+		dev_err(dwc->dev, "failed to add gadget\n");
+		goto err5;
+	}
+
+	if (DWC3_IP_IS(DWC32) && dwc->maximum_speed == USB_SPEED_SUPER_PLUS)
+		dwc3_gadget_set_ssp_rate(dwc->gadget, dwc->max_ssp_rate);
+	else
+		dwc3_gadget_set_speed(dwc->gadget, dwc->maximum_speed);
+
+	return 0;
+
+err5:
+	dwc3_gadget_free_endpoints(dwc);
+err4:
+	usb_put_gadget(dwc->gadget);
+	dwc->gadget = NULL;
+err3:
+	dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,
+			dwc->bounce_addr);
+
+err2:
+	kfree(dwc->setup_buf);
+
+err1:
+	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ep0_trb) * 2,
+			dwc->ep0_trb, dwc->ep0_trb_addr);
+
+err0:
+	return ret;
+}
+
+/* -------------------------------------------------------------------------- */
+
+void dwc3_gadget_exit(struct dwc3 *dwc)
+{
+	if (!dwc->gadget)
+		return;
+
+	usb_del_gadget(dwc->gadget);
+	dwc3_gadget_free_endpoints(dwc);
+	usb_put_gadget(dwc->gadget);
+	dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,
+			  dwc->bounce_addr);
+	kfree(dwc->setup_buf);
+	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ep0_trb) * 2,
+			  dwc->ep0_trb, dwc->ep0_trb_addr);
+}
+
+int dwc3_gadget_suspend(struct dwc3 *dwc)
+{
+	unsigned long flags;
+	int ret;
+
+	if (!dwc->gadget_driver)
+		return 0;
+
+	ret = dwc3_gadget_soft_disconnect(dwc);
+	if (ret)
+		goto err;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	dwc3_disconnect_gadget(dwc);
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return 0;
+
+err:
+	/*
+	 * Attempt to reset the controller's state. Likely no
+	 * communication can be established until the host
+	 * performs a port reset.
+	 */
+	if (dwc->softconnect)
+		dwc3_gadget_soft_connect(dwc);
+
+	return ret;
+}
+
+int dwc3_gadget_resume(struct dwc3 *dwc)
+{
+	if (!dwc->gadget_driver || !dwc->softconnect)
+		return 0;
+
+	return dwc3_gadget_soft_connect(dwc);
+}
+
+void dwc3_gadget_process_pending_events(struct dwc3 *dwc)
+{
+	if (dwc->pending_events) {
+		dwc3_interrupt(dwc->irq_gadget, dwc->ev_buf);
+		dwc3_thread_interrupt(dwc->irq_gadget, dwc->ev_buf);
+		pm_runtime_put(dwc->dev);
+		dwc->pending_events = false;
+		enable_irq(dwc->irq_gadget);
+	}
+}