Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 2474 insertions, 0 deletions

diff --git a/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c b/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c
new file mode 100644
index 0000000000..0eed0e0384
--- /dev/null
+++ b/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c
@@ -0,0 +1,2474 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cadence USBHS-DEV Driver - gadget side.
+ *
+ * Copyright (C) 2023 Cadence Design Systems.
+ *
+ * Authors: Pawel Laszczak <pawell@cadence.com>
+ */
+
+/*
+ * Work around 1:
+ * At some situations, the controller may get stale data address in TRB
+ * at below sequences:
+ * 1. Controller read TRB includes data address
+ * 2. Software updates TRBs includes data address and Cycle bit
+ * 3. Controller read TRB which includes Cycle bit
+ * 4. DMA run with stale data address
+ *
+ * To fix this problem, driver needs to make the first TRB in TD as invalid.
+ * After preparing all TRBs driver needs to check the position of DMA and
+ * if the DMA point to the first just added TRB and doorbell is 1,
+ * then driver must defer making this TRB as valid. This TRB will be make
+ * as valid during adding next TRB only if DMA is stopped or at TRBERR
+ * interrupt.
+ *
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/pm_runtime.h>
+#include <linux/interrupt.h>
+#include <linux/property.h>
+#include <linux/dmapool.h>
+#include <linux/iopoll.h>
+
+#include "cdns2-gadget.h"
+#include "cdns2-trace.h"
+
+/**
+ * set_reg_bit_32 - set bit in given 32 bits register.
+ * @ptr: register address.
+ * @mask: bits to set.
+ */
+static void set_reg_bit_32(void __iomem *ptr, u32 mask)
+{
+	mask = readl(ptr) | mask;
+	writel(mask, ptr);
+}
+
+/*
+ * clear_reg_bit_32 - clear bit in given 32 bits register.
+ * @ptr: register address.
+ * @mask: bits to clear.
+ */
+static void clear_reg_bit_32(void __iomem *ptr, u32 mask)
+{
+	mask = readl(ptr) & ~mask;
+	writel(mask, ptr);
+}
+
+/* Clear bit in given 8 bits register. */
+static void clear_reg_bit_8(void __iomem *ptr, u8 mask)
+{
+	mask = readb(ptr) & ~mask;
+	writeb(mask, ptr);
+}
+
+/* Set bit in given 16 bits register. */
+void set_reg_bit_8(void __iomem *ptr, u8 mask)
+{
+	mask = readb(ptr) | mask;
+	writeb(mask, ptr);
+}
+
+static int cdns2_get_dma_pos(struct cdns2_device *pdev,
+			     struct cdns2_endpoint *pep)
+{
+	int dma_index;
+
+	dma_index = readl(&pdev->adma_regs->ep_traddr) - pep->ring.dma;
+
+	return dma_index / TRB_SIZE;
+}
+
+/* Get next private request from list. */
+struct cdns2_request *cdns2_next_preq(struct list_head *list)
+{
+	return list_first_entry_or_null(list, struct cdns2_request, list);
+}
+
+void cdns2_select_ep(struct cdns2_device *pdev, u32 ep)
+{
+	if (pdev->selected_ep == ep)
+		return;
+
+	pdev->selected_ep = ep;
+	writel(ep, &pdev->adma_regs->ep_sel);
+}
+
+dma_addr_t cdns2_trb_virt_to_dma(struct cdns2_endpoint *pep,
+				 struct cdns2_trb *trb)
+{
+	u32 offset = (char *)trb - (char *)pep->ring.trbs;
+
+	return pep->ring.dma + offset;
+}
+
+static void cdns2_free_tr_segment(struct cdns2_endpoint *pep)
+{
+	struct cdns2_device *pdev = pep->pdev;
+	struct cdns2_ring *ring = &pep->ring;
+
+	if (pep->ring.trbs) {
+		dma_pool_free(pdev->eps_dma_pool, ring->trbs, ring->dma);
+		memset(ring, 0, sizeof(*ring));
+	}
+}
+
+/* Allocates Transfer Ring segment. */
+static int cdns2_alloc_tr_segment(struct cdns2_endpoint *pep)
+{
+	struct cdns2_device *pdev = pep->pdev;
+	struct cdns2_trb *link_trb;
+	struct cdns2_ring *ring;
+
+	ring = &pep->ring;
+
+	if (!ring->trbs) {
+		ring->trbs = dma_pool_alloc(pdev->eps_dma_pool,
+					    GFP_DMA32 | GFP_ATOMIC,
+					    &ring->dma);
+		if (!ring->trbs)
+			return -ENOMEM;
+	}
+
+	memset(ring->trbs, 0, TR_SEG_SIZE);
+
+	if (!pep->num)
+		return 0;
+
+	/* Initialize the last TRB as Link TRB */
+	link_trb = (ring->trbs + (TRBS_PER_SEGMENT - 1));
+	link_trb->buffer = cpu_to_le32(TRB_BUFFER(ring->dma));
+	link_trb->control = cpu_to_le32(TRB_CYCLE | TRB_TYPE(TRB_LINK) |
+					TRB_TOGGLE);
+
+	return 0;
+}
+
+/*
+ * Stalls and flushes selected endpoint.
+ * Endpoint must be selected before invoking this function.
+ */
+static void cdns2_ep_stall_flush(struct cdns2_endpoint *pep)
+{
+	struct cdns2_device *pdev = pep->pdev;
+	int val;
+
+	trace_cdns2_ep_halt(pep, 1, 1);
+
+	writel(DMA_EP_CMD_DFLUSH, &pdev->adma_regs->ep_cmd);
+
+	/* Wait for DFLUSH cleared. */
+	readl_poll_timeout_atomic(&pdev->adma_regs->ep_cmd, val,
+				  !(val & DMA_EP_CMD_DFLUSH), 1, 1000);
+	pep->ep_state |= EP_STALLED;
+	pep->ep_state &= ~EP_STALL_PENDING;
+}
+
+/*
+ * Increment a trb index.
+ *
+ * The index should never point to the last link TRB in TR. After incrementing,
+ * if it point to the link TRB, wrap around to the beginning and revert
+ * cycle state bit. The link TRB is always at the last TRB entry.
+ */
+static void cdns2_ep_inc_trb(int *index, u8 *cs, int trb_in_seg)
+{
+	(*index)++;
+	if (*index == (trb_in_seg - 1)) {
+		*index = 0;
+		*cs ^=  1;
+	}
+}
+
+static void cdns2_ep_inc_enq(struct cdns2_ring *ring)
+{
+	ring->free_trbs--;
+	cdns2_ep_inc_trb(&ring->enqueue, &ring->pcs, TRBS_PER_SEGMENT);
+}
+
+static void cdns2_ep_inc_deq(struct cdns2_ring *ring)
+{
+	ring->free_trbs++;
+	cdns2_ep_inc_trb(&ring->dequeue, &ring->ccs, TRBS_PER_SEGMENT);
+}
+
+/*
+ * Enable/disable LPM.
+ *
+ * If bit USBCS_LPMNYET is not set and device receive Extended Token packet,
+ * then controller answer with ACK handshake.
+ * If bit USBCS_LPMNYET is set and device receive Extended Token packet,
+ * then controller answer with NYET handshake.
+ */
+static void cdns2_enable_l1(struct cdns2_device *pdev, int enable)
+{
+	if (enable) {
+		clear_reg_bit_8(&pdev->usb_regs->usbcs, USBCS_LPMNYET);
+		writeb(LPMCLOCK_SLEEP_ENTRY, &pdev->usb_regs->lpmclock);
+	} else {
+		set_reg_bit_8(&pdev->usb_regs->usbcs, USBCS_LPMNYET);
+	}
+}
+
+static enum usb_device_speed cdns2_get_speed(struct cdns2_device *pdev)
+{
+	u8 speed = readb(&pdev->usb_regs->speedctrl);
+
+	if (speed & SPEEDCTRL_HS)
+		return USB_SPEED_HIGH;
+	else if (speed & SPEEDCTRL_FS)
+		return USB_SPEED_FULL;
+
+	return USB_SPEED_UNKNOWN;
+}
+
+static struct cdns2_trb *cdns2_next_trb(struct cdns2_endpoint *pep,
+					struct cdns2_trb *trb)
+{
+	if (trb == (pep->ring.trbs + (TRBS_PER_SEGMENT - 1)))
+		return pep->ring.trbs;
+	else
+		return ++trb;
+}
+
+void cdns2_gadget_giveback(struct cdns2_endpoint *pep,
+			   struct cdns2_request *preq,
+			   int status)
+{
+	struct usb_request *request = &preq->request;
+	struct cdns2_device *pdev = pep->pdev;
+
+	list_del_init(&preq->list);
+
+	if (request->status == -EINPROGRESS)
+		request->status = status;
+
+	usb_gadget_unmap_request_by_dev(pdev->dev, request, pep->dir);
+
+	/* All TRBs have finished, clear the counter. */
+	preq->finished_trb = 0;
+
+	trace_cdns2_request_giveback(preq);
+
+	if (request->complete) {
+		spin_unlock(&pdev->lock);
+		usb_gadget_giveback_request(&pep->endpoint, request);
+		spin_lock(&pdev->lock);
+	}
+
+	if (request->buf == pdev->zlp_buf)
+		cdns2_gadget_ep_free_request(&pep->endpoint, request);
+}
+
+static void cdns2_wa1_restore_cycle_bit(struct cdns2_endpoint *pep)
+{
+	/* Work around for stale data address in TRB. */
+	if (pep->wa1_set) {
+		trace_cdns2_wa1(pep, "restore cycle bit");
+
+		pep->wa1_set = 0;
+		pep->wa1_trb_index = 0xFFFF;
+		if (pep->wa1_cycle_bit)
+			pep->wa1_trb->control |= cpu_to_le32(0x1);
+		else
+			pep->wa1_trb->control &= cpu_to_le32(~0x1);
+	}
+}
+
+static int cdns2_wa1_update_guard(struct cdns2_endpoint *pep,
+				  struct cdns2_trb *trb)
+{
+	struct cdns2_device *pdev = pep->pdev;
+
+	if (!pep->wa1_set) {
+		u32 doorbell;
+
+		doorbell = !!(readl(&pdev->adma_regs->ep_cmd) & DMA_EP_CMD_DRDY);
+
+		if (doorbell) {
+			pep->wa1_cycle_bit = pep->ring.pcs ? TRB_CYCLE : 0;
+			pep->wa1_set = 1;
+			pep->wa1_trb = trb;
+			pep->wa1_trb_index = pep->ring.enqueue;
+			trace_cdns2_wa1(pep, "set guard");
+			return 0;
+		}
+	}
+	return 1;
+}
+
+static void cdns2_wa1_tray_restore_cycle_bit(struct cdns2_device *pdev,
+					     struct cdns2_endpoint *pep)
+{
+	int dma_index;
+	u32 doorbell;
+
+	doorbell = !!(readl(&pdev->adma_regs->ep_cmd) & DMA_EP_CMD_DRDY);
+	dma_index = cdns2_get_dma_pos(pdev, pep);
+
+	if (!doorbell || dma_index != pep->wa1_trb_index)
+		cdns2_wa1_restore_cycle_bit(pep);
+}
+
+static int cdns2_prepare_ring(struct cdns2_device *pdev,
+			      struct cdns2_endpoint *pep,
+			      int num_trbs)
+{
+	struct cdns2_trb *link_trb = NULL;
+	int doorbell, dma_index;
+	struct cdns2_ring *ring;
+	u32 ch_bit = 0;
+
+	ring = &pep->ring;
+
+	if (num_trbs > ring->free_trbs) {
+		pep->ep_state |= EP_RING_FULL;
+		trace_cdns2_no_room_on_ring("Ring full\n");
+		return -ENOBUFS;
+	}
+
+	if ((ring->enqueue + num_trbs)  >= (TRBS_PER_SEGMENT - 1)) {
+		doorbell = !!(readl(&pdev->adma_regs->ep_cmd) & DMA_EP_CMD_DRDY);
+		dma_index = cdns2_get_dma_pos(pdev, pep);
+
+		/* Driver can't update LINK TRB if it is current processed. */
+		if (doorbell && dma_index == TRBS_PER_SEGMENT - 1) {
+			pep->ep_state |= EP_DEFERRED_DRDY;
+			return -ENOBUFS;
+		}
+
+		/* Update C bt in Link TRB before starting DMA. */
+		link_trb = ring->trbs + (TRBS_PER_SEGMENT - 1);
+
+		/*
+		 * For TRs size equal 2 enabling TRB_CHAIN for epXin causes
+		 * that DMA stuck at the LINK TRB.
+		 * On the other hand, removing TRB_CHAIN for longer TRs for
+		 * epXout cause that DMA stuck after handling LINK TRB.
+		 * To eliminate this strange behavioral driver set TRB_CHAIN
+		 * bit only for TR size > 2.
+		 */
+		if (pep->type == USB_ENDPOINT_XFER_ISOC || TRBS_PER_SEGMENT > 2)
+			ch_bit = TRB_CHAIN;
+
+		link_trb->control = cpu_to_le32(((ring->pcs) ? TRB_CYCLE : 0) |
+				    TRB_TYPE(TRB_LINK) | TRB_TOGGLE | ch_bit);
+	}
+
+	return 0;
+}
+
+static void cdns2_dbg_request_trbs(struct cdns2_endpoint *pep,
+				   struct cdns2_request *preq)
+{
+	struct cdns2_trb *link_trb = pep->ring.trbs + (TRBS_PER_SEGMENT - 1);
+	struct cdns2_trb *trb = preq->trb;
+	int num_trbs = preq->num_of_trb;
+	int i = 0;
+
+	while (i < num_trbs) {
+		trace_cdns2_queue_trb(pep, trb + i);
+		if (trb + i == link_trb) {
+			trb = pep->ring.trbs;
+			num_trbs = num_trbs - i;
+			i = 0;
+		} else {
+			i++;
+		}
+	}
+}
+
+static unsigned int cdns2_count_trbs(struct cdns2_endpoint *pep,
+				     u64 addr, u64 len)
+{
+	unsigned int num_trbs = 1;
+
+	if (pep->type == USB_ENDPOINT_XFER_ISOC) {
+		/*
+		 * To speed up DMA performance address should not exceed 4KB.
+		 * for high bandwidth transfer and driver will split
+		 * such buffer into two TRBs.
+		 */
+		num_trbs = DIV_ROUND_UP(len +
+					(addr & (TRB_MAX_ISO_BUFF_SIZE - 1)),
+					TRB_MAX_ISO_BUFF_SIZE);
+
+		if (pep->interval > 1)
+			num_trbs = pep->dir ? num_trbs * pep->interval : 1;
+	} else if (pep->dir) {
+		/*
+		 * One extra link trb for IN direction.
+		 * Sometimes DMA doesn't want advance to next TD and transfer
+		 * hangs. This extra Link TRB force DMA to advance to next TD.
+		 */
+		num_trbs++;
+	}
+
+	return num_trbs;
+}
+
+static unsigned int cdns2_count_sg_trbs(struct cdns2_endpoint *pep,
+					struct usb_request *req)
+{
+	unsigned int i, len, full_len, num_trbs = 0;
+	struct scatterlist *sg;
+	int trb_len = 0;
+
+	full_len = req->length;
+
+	for_each_sg(req->sg, sg, req->num_sgs, i) {
+		len = sg_dma_len(sg);
+		num_trbs += cdns2_count_trbs(pep, sg_dma_address(sg), len);
+		len = min(len, full_len);
+
+		/*
+		 * For HS ISO transfer TRBs should not exceed max packet size.
+		 * When DMA is working, and data exceed max packet size then
+		 * some data will be read in single mode instead burst mode.
+		 * This behavior will drastically reduce the copying speed.
+		 * To avoid this we need one or two extra TRBs.
+		 * This issue occurs for UVC class with sg_supported = 1
+		 * because buffers addresses are not aligned to 1024.
+		 */
+		if (pep->type == USB_ENDPOINT_XFER_ISOC) {
+			u8 temp;
+
+			trb_len += len;
+			temp = trb_len >> 10;
+
+			if (temp) {
+				if (trb_len % 1024)
+					num_trbs = num_trbs + temp;
+				else
+					num_trbs = num_trbs + temp - 1;
+
+				trb_len = trb_len - (temp << 10);
+			}
+		}
+
+		full_len -= len;
+		if (full_len == 0)
+			break;
+	}
+
+	return num_trbs;
+}
+
+/*
+ * Function prepares the array with optimized AXI burst value for different
+ * transfer lengths. Controller handles the final data which are less
+ * then AXI burst size as single byte transactions.
+ * e.g.:
+ * Let's assume that driver prepares trb with trb->length 700 and burst size
+ * will be set to 128. In this case the controller will handle a first 512 as
+ * single AXI transaction but the next 188 bytes will be handled
+ * as 47 separate AXI transaction.
+ * The better solution is to use the burst size equal 16 and then we will
+ * have only 25 AXI transaction (10 * 64 + 15 *4).
+ */
+static void cdsn2_isoc_burst_opt(struct cdns2_device *pdev)
+{
+	int axi_burst_option[]  =  {1, 2, 4, 8, 16, 32, 64, 128};
+	int best_burst;
+	int array_size;
+	int opt_burst;
+	int trb_size;
+	int i, j;
+
+	array_size = ARRAY_SIZE(axi_burst_option);
+
+	for (i = 0; i <= MAX_ISO_SIZE; i++) {
+		trb_size = i / 4;
+		best_burst = trb_size ? trb_size : 1;
+
+		for (j = 0; j < array_size; j++) {
+			opt_burst = trb_size / axi_burst_option[j];
+			opt_burst += trb_size % axi_burst_option[j];
+
+			if (opt_burst < best_burst) {
+				best_burst = opt_burst;
+				pdev->burst_opt[i] = axi_burst_option[j];
+			}
+		}
+	}
+}
+
+static void cdns2_ep_tx_isoc(struct cdns2_endpoint *pep,
+			     struct cdns2_request *preq,
+			     int num_trbs)
+{
+	struct scatterlist *sg = NULL;
+	u32 remaining_packet_size = 0;
+	struct cdns2_trb *trb;
+	bool first_trb = true;
+	dma_addr_t trb_dma;
+	u32 trb_buff_len;
+	u32 block_length;
+	int td_idx = 0;
+	int split_size;
+	u32 full_len;
+	int enqd_len;
+	int sent_len;
+	int sg_iter;
+	u32 control;
+	int num_tds;
+	u32 length;
+
+	/*
+	 * For OUT direction 1 TD per interval is enough
+	 * because TRBs are not dumped by controller.
+	 */
+	num_tds = pep->dir ? pep->interval : 1;
+	split_size = preq->request.num_sgs ? 1024 : 3072;
+
+	for (td_idx = 0; td_idx < num_tds; td_idx++) {
+		if (preq->request.num_sgs) {
+			sg = preq->request.sg;
+			trb_dma = sg_dma_address(sg);
+			block_length = sg_dma_len(sg);
+		} else {
+			trb_dma = preq->request.dma;
+			block_length = preq->request.length;
+		}
+
+		full_len = preq->request.length;
+		sg_iter = preq->request.num_sgs ? preq->request.num_sgs : 1;
+		remaining_packet_size = split_size;
+
+		for (enqd_len = 0;  enqd_len < full_len;
+		     enqd_len += trb_buff_len) {
+			if (remaining_packet_size == 0)
+				remaining_packet_size = split_size;
+
+			/*
+			 * Calculate TRB length.- buffer can't across 4KB
+			 * and max packet size.
+			 */
+			trb_buff_len = TRB_BUFF_LEN_UP_TO_BOUNDARY(trb_dma);
+			trb_buff_len = min(trb_buff_len, remaining_packet_size);
+			trb_buff_len = min(trb_buff_len, block_length);
+
+			if (trb_buff_len > full_len - enqd_len)
+				trb_buff_len = full_len - enqd_len;
+
+			control = TRB_TYPE(TRB_NORMAL);
+
+			/*
+			 * For IN direction driver has to set the IOC for
+			 * last TRB in last TD.
+			 * For OUT direction driver must set IOC and ISP
+			 * only for last TRB in each TDs.
+			 */
+			if (enqd_len + trb_buff_len >= full_len || !pep->dir)
+				control |= TRB_IOC | TRB_ISP;
+
+			/*
+			 * Don't give the first TRB to the hardware (by toggling
+			 * the cycle bit) until we've finished creating all the
+			 * other TRBs.
+			 */
+			if (first_trb) {
+				first_trb = false;
+				if (pep->ring.pcs == 0)
+					control |= TRB_CYCLE;
+			} else {
+				control |= pep->ring.pcs;
+			}
+
+			if (enqd_len + trb_buff_len < full_len)
+				control |= TRB_CHAIN;
+
+			length = TRB_LEN(trb_buff_len) |
+				 TRB_BURST(pep->pdev->burst_opt[trb_buff_len]);
+
+			trb = pep->ring.trbs + pep->ring.enqueue;
+			trb->buffer = cpu_to_le32(TRB_BUFFER(trb_dma));
+			trb->length = cpu_to_le32(length);
+			trb->control = cpu_to_le32(control);
+
+			trb_dma += trb_buff_len;
+			sent_len = trb_buff_len;
+
+			if (sg && sent_len >= block_length) {
+				/* New sg entry */
+				--sg_iter;
+				sent_len -= block_length;
+				if (sg_iter != 0) {
+					sg = sg_next(sg);
+					trb_dma = sg_dma_address(sg);
+					block_length = sg_dma_len(sg);
+				}
+			}
+
+			remaining_packet_size -= trb_buff_len;
+			block_length -= sent_len;
+			preq->end_trb = pep->ring.enqueue;
+
+			cdns2_ep_inc_enq(&pep->ring);
+		}
+	}
+}
+
+static void cdns2_ep_tx_bulk(struct cdns2_endpoint *pep,
+			     struct cdns2_request *preq,
+			     int trbs_per_td)
+{
+	struct scatterlist *sg = NULL;
+	struct cdns2_ring *ring;
+	struct cdns2_trb *trb;
+	dma_addr_t trb_dma;
+	int sg_iter = 0;
+	u32 control;
+	u32 length;
+
+	if (preq->request.num_sgs) {
+		sg = preq->request.sg;
+		trb_dma = sg_dma_address(sg);
+		length = sg_dma_len(sg);
+	} else {
+		trb_dma = preq->request.dma;
+		length = preq->request.length;
+	}
+
+	ring = &pep->ring;
+
+	for (sg_iter = 0; sg_iter < trbs_per_td; sg_iter++) {
+		control = TRB_TYPE(TRB_NORMAL) | ring->pcs | TRB_ISP;
+		trb = pep->ring.trbs + ring->enqueue;
+
+		if (pep->dir && sg_iter == trbs_per_td - 1) {
+			preq->end_trb = ring->enqueue;
+			control = ring->pcs | TRB_TYPE(TRB_LINK) | TRB_CHAIN
+				  | TRB_IOC;
+			cdns2_ep_inc_enq(&pep->ring);
+
+			if (ring->enqueue == 0)
+				control |= TRB_TOGGLE;
+
+			/* Point to next bad TRB. */
+			trb->buffer = cpu_to_le32(pep->ring.dma +
+						  (ring->enqueue * TRB_SIZE));
+			trb->length = 0;
+			trb->control = cpu_to_le32(control);
+			break;
+		}
+
+		/*
+		 * Don't give the first TRB to the hardware (by toggling
+		 * the cycle bit) until we've finished creating all the
+		 * other TRBs.
+		 */
+		if (sg_iter == 0)
+			control = control ^ TRB_CYCLE;
+
+		/* For last TRB in TD. */
+		if (sg_iter == (trbs_per_td - (pep->dir ? 2 : 1)))
+			control |= TRB_IOC;
+		else
+			control |= TRB_CHAIN;
+
+		trb->buffer = cpu_to_le32(trb_dma);
+		trb->length = cpu_to_le32(TRB_BURST(pep->trb_burst_size) |
+					   TRB_LEN(length));
+		trb->control = cpu_to_le32(control);
+
+		if (sg && sg_iter < (trbs_per_td - 1)) {
+			sg = sg_next(sg);
+			trb_dma = sg_dma_address(sg);
+			length = sg_dma_len(sg);
+		}
+
+		preq->end_trb = ring->enqueue;
+		cdns2_ep_inc_enq(&pep->ring);
+	}
+}
+
+static void cdns2_set_drdy(struct cdns2_device *pdev,
+			   struct cdns2_endpoint *pep)
+{
+	trace_cdns2_ring(pep);
+
+	/*
+	 * Memory barrier - Cycle Bit must be set before doorbell.
+	 */
+	dma_wmb();
+
+	/* Clearing TRBERR and DESCMIS before setting DRDY. */
+	writel(DMA_EP_STS_TRBERR | DMA_EP_STS_DESCMIS,
+	       &pdev->adma_regs->ep_sts);
+	writel(DMA_EP_CMD_DRDY, &pdev->adma_regs->ep_cmd);
+
+	if (readl(&pdev->adma_regs->ep_sts) & DMA_EP_STS_TRBERR) {
+		writel(DMA_EP_STS_TRBERR, &pdev->adma_regs->ep_sts);
+		writel(DMA_EP_CMD_DRDY, &pdev->adma_regs->ep_cmd);
+	}
+
+	trace_cdns2_doorbell_epx(pep, readl(&pdev->adma_regs->ep_traddr));
+}
+
+static int cdns2_prepare_first_isoc_transfer(struct cdns2_device *pdev,
+					     struct cdns2_endpoint *pep)
+{
+	struct cdns2_trb *trb;
+	u32 buffer;
+	u8 hw_ccs;
+
+	if ((readl(&pdev->adma_regs->ep_cmd) & DMA_EP_CMD_DRDY))
+		return -EBUSY;
+
+	if (!pep->dir) {
+		set_reg_bit_32(&pdev->adma_regs->ep_cfg, DMA_EP_CFG_ENABLE);
+		writel(pep->ring.dma + pep->ring.dequeue,
+		       &pdev->adma_regs->ep_traddr);
+		return 0;
+	}
+
+	/*
+	 * The first packet after doorbell can be corrupted so,
+	 * driver prepares 0 length packet as first packet.
+	 */
+	buffer = pep->ring.dma + pep->ring.dequeue * TRB_SIZE;
+	hw_ccs = !!DMA_EP_STS_CCS(readl(&pdev->adma_regs->ep_sts));
+
+	trb = &pep->ring.trbs[TRBS_PER_SEGMENT];
+	trb->length = 0;
+	trb->buffer = cpu_to_le32(TRB_BUFFER(buffer));
+	trb->control = cpu_to_le32((hw_ccs ? TRB_CYCLE : 0) | TRB_TYPE(TRB_NORMAL));
+
+	/*
+	 * LINK TRB is used to force updating cycle bit in controller and
+	 * move to correct place in transfer ring.
+	 */
+	trb++;
+	trb->length = 0;
+	trb->buffer = cpu_to_le32(TRB_BUFFER(buffer));
+	trb->control = cpu_to_le32((hw_ccs ? TRB_CYCLE : 0) |
+				    TRB_TYPE(TRB_LINK) | TRB_CHAIN);
+
+	if (hw_ccs !=  pep->ring.ccs)
+		trb->control |= cpu_to_le32(TRB_TOGGLE);
+
+	set_reg_bit_32(&pdev->adma_regs->ep_cfg, DMA_EP_CFG_ENABLE);
+	writel(pep->ring.dma + (TRBS_PER_SEGMENT * TRB_SIZE),
+	       &pdev->adma_regs->ep_traddr);
+
+	return 0;
+}
+
+/* Prepare and start transfer on no-default endpoint. */
+static int cdns2_ep_run_transfer(struct cdns2_endpoint *pep,
+				 struct cdns2_request *preq)
+{
+	struct cdns2_device *pdev = pep->pdev;
+	struct cdns2_ring *ring;
+	u32 togle_pcs = 1;
+	int num_trbs;
+	int ret;
+
+	cdns2_select_ep(pdev, pep->endpoint.address);
+
+	if (preq->request.sg)
+		num_trbs = cdns2_count_sg_trbs(pep, &preq->request);
+	else
+		num_trbs = cdns2_count_trbs(pep, preq->request.dma,
+					    preq->request.length);
+
+	ret = cdns2_prepare_ring(pdev, pep, num_trbs);
+	if (ret)
+		return ret;
+
+	ring = &pep->ring;
+	preq->start_trb = ring->enqueue;
+	preq->trb = ring->trbs + ring->enqueue;
+
+	if (usb_endpoint_xfer_isoc(pep->endpoint.desc)) {
+		cdns2_ep_tx_isoc(pep, preq, num_trbs);
+	} else {
+		togle_pcs = cdns2_wa1_update_guard(pep, ring->trbs + ring->enqueue);
+		cdns2_ep_tx_bulk(pep, preq, num_trbs);
+	}
+
+	preq->num_of_trb = num_trbs;
+
+	/*
+	 * Memory barrier - cycle bit must be set as the last operation.
+	 */
+	dma_wmb();
+
+	/* Give the TD to the consumer. */
+	if (togle_pcs)
+		preq->trb->control = preq->trb->control ^ cpu_to_le32(1);
+
+	cdns2_wa1_tray_restore_cycle_bit(pdev, pep);
+	cdns2_dbg_request_trbs(pep, preq);
+
+	if (!pep->wa1_set && !(pep->ep_state & EP_STALLED) && !pep->skip) {
+		if (pep->type == USB_ENDPOINT_XFER_ISOC) {
+			ret = cdns2_prepare_first_isoc_transfer(pdev, pep);
+			if (ret)
+				return 0;
+		}
+
+		cdns2_set_drdy(pdev, pep);
+	}
+
+	return 0;
+}
+
+/* Prepare and start transfer for all not started requests. */
+static int cdns2_start_all_request(struct cdns2_device *pdev,
+				   struct cdns2_endpoint *pep)
+{
+	struct cdns2_request *preq;
+	int ret;
+
+	while (!list_empty(&pep->deferred_list)) {
+		preq = cdns2_next_preq(&pep->deferred_list);
+
+		ret = cdns2_ep_run_transfer(pep, preq);
+		if (ret)
+			return ret;
+
+		list_move_tail(&preq->list, &pep->pending_list);
+	}
+
+	pep->ep_state &= ~EP_RING_FULL;
+
+	return 0;
+}
+
+/*
+ * Check whether trb has been handled by DMA.
+ *
+ * Endpoint must be selected before invoking this function.
+ *
+ * Returns false if request has not been handled by DMA, else returns true.
+ *
+ * SR - start ring
+ * ER - end ring
+ * DQ = ring->dequeue - dequeue position
+ * EQ = ring->enqueue - enqueue position
+ * ST = preq->start_trb - index of first TRB in transfer ring
+ * ET = preq->end_trb - index of last TRB in transfer ring
+ * CI = current_index - index of processed TRB by DMA.
+ *
+ * As first step, we check if the TRB between the ST and ET.
+ * Then, we check if cycle bit for index pep->dequeue
+ * is correct.
+ *
+ * some rules:
+ * 1. ring->dequeue never equals to current_index.
+ * 2  ring->enqueue never exceed ring->dequeue
+ * 3. exception: ring->enqueue == ring->dequeue
+ *    and ring->free_trbs is zero.
+ *    This case indicate that TR is full.
+ *
+ * At below two cases, the request have been handled.
+ * Case 1 - ring->dequeue < current_index
+ *      SR ... EQ ... DQ ... CI ... ER
+ *      SR ... DQ ... CI ... EQ ... ER
+ *
+ * Case 2 - ring->dequeue > current_index
+ * This situation takes place when CI go through the LINK TRB at the end of
+ * transfer ring.
+ *      SR ... CI ... EQ ... DQ ... ER
+ */
+static bool cdns2_trb_handled(struct cdns2_endpoint *pep,
+			      struct cdns2_request *preq)
+{
+	struct cdns2_device *pdev = pep->pdev;
+	struct cdns2_ring *ring;
+	struct cdns2_trb *trb;
+	int current_index = 0;
+	int handled = 0;
+	int doorbell;
+
+	ring = &pep->ring;
+	current_index = cdns2_get_dma_pos(pdev, pep);
+	doorbell = !!(readl(&pdev->adma_regs->ep_cmd) & DMA_EP_CMD_DRDY);
+
+	/*
+	 * Only ISO transfer can use 2 entries outside the standard
+	 * Transfer Ring. First of them is used as zero length packet and the
+	 * second as LINK TRB.
+	 */
+	if (current_index >= TRBS_PER_SEGMENT)
+		goto finish;
+
+	/* Current trb doesn't belong to this request. */
+	if (preq->start_trb < preq->end_trb) {
+		if (ring->dequeue > preq->end_trb)
+			goto finish;
+
+		if (ring->dequeue < preq->start_trb)
+			goto finish;
+	}
+
+	if (preq->start_trb > preq->end_trb && ring->dequeue > preq->end_trb &&
+	    ring->dequeue < preq->start_trb)
+		goto finish;
+
+	if (preq->start_trb == preq->end_trb && ring->dequeue != preq->end_trb)
+		goto finish;
+
+	trb = &ring->trbs[ring->dequeue];
+
+	if ((le32_to_cpu(trb->control) & TRB_CYCLE) != ring->ccs)
+		goto finish;
+
+	if (doorbell == 1 && current_index == ring->dequeue)
+		goto finish;
+
+	/* The corner case for TRBS_PER_SEGMENT equal 2). */
+	if (TRBS_PER_SEGMENT == 2 && pep->type != USB_ENDPOINT_XFER_ISOC) {
+		handled = 1;
+		goto finish;
+	}
+
+	if (ring->enqueue == ring->dequeue &&
+	    ring->free_trbs == 0) {
+		handled = 1;
+	} else if (ring->dequeue < current_index) {
+		if ((current_index == (TRBS_PER_SEGMENT - 1)) &&
+		    !ring->dequeue)
+			goto finish;
+
+		handled = 1;
+	} else if (ring->dequeue  > current_index) {
+		handled = 1;
+	}
+
+finish:
+	trace_cdns2_request_handled(preq, current_index, handled);
+
+	return handled;
+}
+
+static void cdns2_skip_isoc_td(struct cdns2_device *pdev,
+			       struct cdns2_endpoint *pep,
+			       struct cdns2_request *preq)
+{
+	struct cdns2_trb *trb;
+	int i;
+
+	trb = pep->ring.trbs + pep->ring.dequeue;
+
+	for (i = preq->finished_trb ; i < preq->num_of_trb; i++) {
+		preq->finished_trb++;
+		trace_cdns2_complete_trb(pep, trb);
+		cdns2_ep_inc_deq(&pep->ring);
+		trb = cdns2_next_trb(pep, trb);
+	}
+
+	cdns2_gadget_giveback(pep, preq, 0);
+	cdns2_prepare_first_isoc_transfer(pdev, pep);
+	pep->skip = false;
+	cdns2_set_drdy(pdev, pep);
+}
+
+static void cdns2_transfer_completed(struct cdns2_device *pdev,
+				     struct cdns2_endpoint *pep)
+{
+	struct cdns2_request *preq = NULL;
+	bool request_handled = false;
+	struct cdns2_trb *trb;
+
+	while (!list_empty(&pep->pending_list)) {
+		preq = cdns2_next_preq(&pep->pending_list);
+		trb = pep->ring.trbs + pep->ring.dequeue;
+
+		/*
+		 * The TRB was changed as link TRB, and the request
+		 * was handled at ep_dequeue.
+		 */
+		while (TRB_FIELD_TO_TYPE(le32_to_cpu(trb->control)) == TRB_LINK &&
+		       le32_to_cpu(trb->length)) {
+			trace_cdns2_complete_trb(pep, trb);
+			cdns2_ep_inc_deq(&pep->ring);
+			trb = pep->ring.trbs + pep->ring.dequeue;
+		}
+
+		/*
+		 * Re-select endpoint. It could be changed by other CPU
+		 * during handling usb_gadget_giveback_request.
+		 */
+		cdns2_select_ep(pdev, pep->endpoint.address);
+
+		while (cdns2_trb_handled(pep, preq)) {
+			preq->finished_trb++;
+
+			if (preq->finished_trb >= preq->num_of_trb)
+				request_handled = true;
+
+			trb = pep->ring.trbs + pep->ring.dequeue;
+			trace_cdns2_complete_trb(pep, trb);
+
+			if (pep->dir && pep->type == USB_ENDPOINT_XFER_ISOC)
+				/*
+				 * For ISOC IN controller doens't update the
+				 * trb->length.
+				 */
+				preq->request.actual = preq->request.length;
+			else
+				preq->request.actual +=
+					TRB_LEN(le32_to_cpu(trb->length));
+
+			cdns2_ep_inc_deq(&pep->ring);
+		}
+
+		if (request_handled) {
+			cdns2_gadget_giveback(pep, preq, 0);
+			request_handled = false;
+		} else {
+			goto prepare_next_td;
+		}
+
+		if (pep->type != USB_ENDPOINT_XFER_ISOC &&
+		    TRBS_PER_SEGMENT == 2)
+			break;
+	}
+
+prepare_next_td:
+	if (pep->skip && preq)
+		cdns2_skip_isoc_td(pdev, pep, preq);
+
+	if (!(pep->ep_state & EP_STALLED) &&
+	    !(pep->ep_state & EP_STALL_PENDING))
+		cdns2_start_all_request(pdev, pep);
+}
+
+static void cdns2_wakeup(struct cdns2_device *pdev)
+{
+	if (!pdev->may_wakeup)
+		return;
+
+	/* Start driving resume signaling to indicate remote wakeup. */
+	set_reg_bit_8(&pdev->usb_regs->usbcs, USBCS_SIGRSUME);
+}
+
+static void cdns2_rearm_transfer(struct cdns2_endpoint *pep, u8 rearm)
+{
+	struct cdns2_device *pdev = pep->pdev;
+
+	cdns2_wa1_restore_cycle_bit(pep);
+
+	if (rearm) {
+		trace_cdns2_ring(pep);
+
+		/* Cycle Bit must be updated before arming DMA. */
+		dma_wmb();
+
+		writel(DMA_EP_CMD_DRDY, &pdev->adma_regs->ep_cmd);
+
+		cdns2_wakeup(pdev);
+
+		trace_cdns2_doorbell_epx(pep,
+					 readl(&pdev->adma_regs->ep_traddr));
+	}
+}
+
+static void cdns2_handle_epx_interrupt(struct cdns2_endpoint *pep)
+{
+	struct cdns2_device *pdev = pep->pdev;
+	u8 isoerror = 0;
+	u32 ep_sts_reg;
+	u32 val;
+
+	cdns2_select_ep(pdev, pep->endpoint.address);
+
+	trace_cdns2_epx_irq(pdev, pep);
+
+	ep_sts_reg = readl(&pdev->adma_regs->ep_sts);
+	writel(ep_sts_reg, &pdev->adma_regs->ep_sts);
+
+	if (pep->type == USB_ENDPOINT_XFER_ISOC) {
+		u8 mult;
+		u8 cs;
+
+		mult = USB_EP_MAXP_MULT(pep->endpoint.desc->wMaxPacketSize);
+		cs = pep->dir ? readb(&pdev->epx_regs->ep[pep->num - 1].txcs) :
+				readb(&pdev->epx_regs->ep[pep->num - 1].rxcs);
+		if (mult > 0)
+			isoerror = EPX_CS_ERR(cs);
+	}
+
+	/*
+	 * Sometimes ISO Error for mult=1 or mult=2 is not propagated on time
+	 * from USB module to DMA module. To protect against this driver
+	 * checks also the txcs/rxcs registers.
+	 */
+	if ((ep_sts_reg & DMA_EP_STS_ISOERR) || isoerror) {
+		clear_reg_bit_32(&pdev->adma_regs->ep_cfg, DMA_EP_CFG_ENABLE);
+
+		/* Wait for DBUSY cleared. */
+		readl_poll_timeout_atomic(&pdev->adma_regs->ep_sts, val,
+					  !(val & DMA_EP_STS_DBUSY), 1, 125);
+
+		writel(DMA_EP_CMD_DFLUSH, &pep->pdev->adma_regs->ep_cmd);
+
+		/* Wait for DFLUSH cleared. */
+		readl_poll_timeout_atomic(&pep->pdev->adma_regs->ep_cmd, val,
+					  !(val & DMA_EP_CMD_DFLUSH), 1, 10);
+
+		pep->skip = true;
+	}
+
+	if (ep_sts_reg & DMA_EP_STS_TRBERR || pep->skip) {
+		if (pep->ep_state & EP_STALL_PENDING &&
+		    !(ep_sts_reg & DMA_EP_STS_DESCMIS))
+			cdns2_ep_stall_flush(pep);
+
+		/*
+		 * For isochronous transfer driver completes request on
+		 * IOC or on TRBERR. IOC appears only when device receive
+		 * OUT data packet. If host disable stream or lost some packet
+		 * then the only way to finish all queued transfer is to do it
+		 * on TRBERR event.
+		 */
+		if (pep->type == USB_ENDPOINT_XFER_ISOC && !pep->wa1_set) {
+			if (!pep->dir)
+				clear_reg_bit_32(&pdev->adma_regs->ep_cfg,
+						 DMA_EP_CFG_ENABLE);
+
+			cdns2_transfer_completed(pdev, pep);
+			if (pep->ep_state & EP_DEFERRED_DRDY) {
+				pep->ep_state &= ~EP_DEFERRED_DRDY;
+				cdns2_set_drdy(pdev, pep);
+			}
+
+			return;
+		}
+
+		cdns2_transfer_completed(pdev, pep);
+
+		if (!(pep->ep_state & EP_STALLED) &&
+		    !(pep->ep_state & EP_STALL_PENDING)) {
+			if (pep->ep_state & EP_DEFERRED_DRDY) {
+				pep->ep_state &= ~EP_DEFERRED_DRDY;
+				cdns2_start_all_request(pdev, pep);
+			} else {
+				cdns2_rearm_transfer(pep, pep->wa1_set);
+			}
+		}
+
+		return;
+	}
+
+	if ((ep_sts_reg & DMA_EP_STS_IOC) || (ep_sts_reg & DMA_EP_STS_ISP))
+		cdns2_transfer_completed(pdev, pep);
+}
+
+static void cdns2_disconnect_gadget(struct cdns2_device *pdev)
+{
+	if (pdev->gadget_driver && pdev->gadget_driver->disconnect)
+		pdev->gadget_driver->disconnect(&pdev->gadget);
+}
+
+static irqreturn_t cdns2_usb_irq_handler(int irq, void *data)
+{
+	struct cdns2_device *pdev = data;
+	unsigned long reg_ep_ists;
+	u8 reg_usb_irq_m;
+	u8 reg_ext_irq_m;
+	u8 reg_usb_irq;
+	u8 reg_ext_irq;
+
+	if (pdev->in_lpm)
+		return IRQ_NONE;
+
+	reg_usb_irq_m = readb(&pdev->interrupt_regs->usbien);
+	reg_ext_irq_m = readb(&pdev->interrupt_regs->extien);
+
+	/* Mask all sources of interrupt. */
+	writeb(0, &pdev->interrupt_regs->usbien);
+	writeb(0, &pdev->interrupt_regs->extien);
+	writel(0, &pdev->adma_regs->ep_ien);
+
+	/* Clear interrupt sources. */
+	writel(0, &pdev->adma_regs->ep_sts);
+	writeb(0, &pdev->interrupt_regs->usbirq);
+	writeb(0, &pdev->interrupt_regs->extirq);
+
+	reg_ep_ists = readl(&pdev->adma_regs->ep_ists);
+	reg_usb_irq = readb(&pdev->interrupt_regs->usbirq);
+	reg_ext_irq = readb(&pdev->interrupt_regs->extirq);
+
+	if (reg_ep_ists || (reg_usb_irq & reg_usb_irq_m) ||
+	    (reg_ext_irq & reg_ext_irq_m))
+		return IRQ_WAKE_THREAD;
+
+	writeb(USB_IEN_INIT, &pdev->interrupt_regs->usbien);
+	writeb(EXTIRQ_WAKEUP, &pdev->interrupt_regs->extien);
+	writel(~0, &pdev->adma_regs->ep_ien);
+
+	return IRQ_NONE;
+}
+
+static irqreturn_t cdns2_thread_usb_irq_handler(struct cdns2_device *pdev)
+{
+	u8 usb_irq, ext_irq;
+	int speed;
+	int i;
+
+	ext_irq = readb(&pdev->interrupt_regs->extirq) & EXTIRQ_WAKEUP;
+	writeb(ext_irq, &pdev->interrupt_regs->extirq);
+
+	usb_irq = readb(&pdev->interrupt_regs->usbirq) & USB_IEN_INIT;
+	writeb(usb_irq, &pdev->interrupt_regs->usbirq);
+
+	if (!ext_irq && !usb_irq)
+		return IRQ_NONE;
+
+	trace_cdns2_usb_irq(usb_irq, ext_irq);
+
+	if (ext_irq & EXTIRQ_WAKEUP) {
+		if (pdev->gadget_driver && pdev->gadget_driver->resume) {
+			spin_unlock(&pdev->lock);
+			pdev->gadget_driver->resume(&pdev->gadget);
+			spin_lock(&pdev->lock);
+		}
+	}
+
+	if (usb_irq & USBIRQ_LPM) {
+		u8 reg = readb(&pdev->usb_regs->lpmctrl);
+
+		/* LPM1 enter */
+		if (!(reg & LPMCTRLLH_LPMNYET))
+			writeb(0, &pdev->usb_regs->sleep_clkgate);
+	}
+
+	if (usb_irq & USBIRQ_SUSPEND) {
+		if (pdev->gadget_driver && pdev->gadget_driver->suspend) {
+			spin_unlock(&pdev->lock);
+			pdev->gadget_driver->suspend(&pdev->gadget);
+			spin_lock(&pdev->lock);
+		}
+	}
+
+	if (usb_irq & USBIRQ_URESET) {
+		if (pdev->gadget_driver) {
+			pdev->dev_address = 0;
+
+			spin_unlock(&pdev->lock);
+			usb_gadget_udc_reset(&pdev->gadget,
+					     pdev->gadget_driver);
+			spin_lock(&pdev->lock);
+
+			/*
+			 * The USBIRQ_URESET is reported at the beginning of
+			 * reset signal. 100ms is enough time to finish reset
+			 * process. For high-speed reset procedure is completed
+			 * when controller detect HS mode.
+			 */
+			for (i = 0; i < 100; i++) {
+				mdelay(1);
+				speed = cdns2_get_speed(pdev);
+				if (speed == USB_SPEED_HIGH)
+					break;
+			}
+
+			pdev->gadget.speed = speed;
+			cdns2_enable_l1(pdev, 0);
+			cdns2_ep0_config(pdev);
+			pdev->may_wakeup = 0;
+		}
+	}
+
+	if (usb_irq & USBIRQ_SUDAV) {
+		pdev->ep0_stage = CDNS2_SETUP_STAGE;
+		cdns2_handle_setup_packet(pdev);
+	}
+
+	return IRQ_HANDLED;
+}
+
+/* Deferred USB interrupt handler. */
+static irqreturn_t cdns2_thread_irq_handler(int irq, void *data)
+{
+	struct cdns2_device *pdev = data;
+	unsigned long  dma_ep_ists;
+	unsigned long flags;
+	unsigned int bit;
+
+	local_bh_disable();
+	spin_lock_irqsave(&pdev->lock, flags);
+
+	cdns2_thread_usb_irq_handler(pdev);
+
+	dma_ep_ists = readl(&pdev->adma_regs->ep_ists);
+	if (!dma_ep_ists)
+		goto unlock;
+
+	trace_cdns2_dma_ep_ists(dma_ep_ists);
+
+	/* Handle default endpoint OUT. */
+	if (dma_ep_ists & DMA_EP_ISTS_EP_OUT0)
+		cdns2_handle_ep0_interrupt(pdev, USB_DIR_OUT);
+
+	/* Handle default endpoint IN. */
+	if (dma_ep_ists & DMA_EP_ISTS_EP_IN0)
+		cdns2_handle_ep0_interrupt(pdev, USB_DIR_IN);
+
+	dma_ep_ists &= ~(DMA_EP_ISTS_EP_OUT0 | DMA_EP_ISTS_EP_IN0);
+
+	for_each_set_bit(bit, &dma_ep_ists, sizeof(u32) * BITS_PER_BYTE) {
+		u8 ep_idx = bit > 16 ? (bit - 16) * 2 : (bit * 2) - 1;
+
+		/*
+		 * Endpoints in pdev->eps[] are held in order:
+		 * ep0, ep1out, ep1in, ep2out, ep2in... ep15out, ep15in.
+		 * but in dma_ep_ists in order:
+		 * ep0 ep1out ep2out ... ep15out ep0in ep1in .. ep15in
+		 */
+		cdns2_handle_epx_interrupt(&pdev->eps[ep_idx]);
+	}
+
+unlock:
+	writel(~0, &pdev->adma_regs->ep_ien);
+	writeb(USB_IEN_INIT, &pdev->interrupt_regs->usbien);
+	writeb(EXTIRQ_WAKEUP, &pdev->interrupt_regs->extien);
+
+	spin_unlock_irqrestore(&pdev->lock, flags);
+	local_bh_enable();
+
+	return IRQ_HANDLED;
+}
+
+/* Calculates and assigns onchip memory for endpoints. */
+static void cdns2_eps_onchip_buffer_init(struct cdns2_device *pdev)
+{
+	struct cdns2_endpoint *pep;
+	int min_buf_tx = 0;
+	int min_buf_rx = 0;
+	u16 tx_offset = 0;
+	u16 rx_offset = 0;
+	int free;
+	int i;
+
+	for (i = 0; i < CDNS2_ENDPOINTS_NUM; i++) {
+		pep = &pdev->eps[i];
+
+		if (!(pep->ep_state & EP_CLAIMED))
+			continue;
+
+		if (pep->dir)
+			min_buf_tx += pep->buffering;
+		else
+			min_buf_rx += pep->buffering;
+	}
+
+	for (i = 0; i < CDNS2_ENDPOINTS_NUM; i++) {
+		pep = &pdev->eps[i];
+
+		if (!(pep->ep_state & EP_CLAIMED))
+			continue;
+
+		if (pep->dir) {
+			free = pdev->onchip_tx_buf - min_buf_tx;
+
+			if (free + pep->buffering >= 4)
+				free = 4;
+			else
+				free = free + pep->buffering;
+
+			min_buf_tx = min_buf_tx - pep->buffering + free;
+
+			pep->buffering = free;
+
+			writel(tx_offset,
+			       &pdev->epx_regs->txstaddr[pep->num - 1]);
+			pdev->epx_regs->txstaddr[pep->num - 1] = tx_offset;
+
+			dev_dbg(pdev->dev, "%s onchip address %04x, buffering: %d\n",
+				pep->name, tx_offset, pep->buffering);
+
+			tx_offset += pep->buffering * 1024;
+		} else {
+			free = pdev->onchip_rx_buf - min_buf_rx;
+
+			if (free + pep->buffering >= 4)
+				free = 4;
+			else
+				free = free + pep->buffering;
+
+			min_buf_rx = min_buf_rx - pep->buffering + free;
+
+			pep->buffering = free;
+			writel(rx_offset,
+			       &pdev->epx_regs->rxstaddr[pep->num - 1]);
+
+			dev_dbg(pdev->dev, "%s onchip address %04x, buffering: %d\n",
+				pep->name, rx_offset, pep->buffering);
+
+			rx_offset += pep->buffering * 1024;
+		}
+	}
+}
+
+/* Configure hardware endpoint. */
+static int cdns2_ep_config(struct cdns2_endpoint *pep, bool enable)
+{
+	bool is_iso_ep = (pep->type == USB_ENDPOINT_XFER_ISOC);
+	struct cdns2_device *pdev = pep->pdev;
+	u32 max_packet_size;
+	u8 dir = 0;
+	u8 ep_cfg;
+	u8 mult;
+	u32 val;
+	int ret;
+
+	switch (pep->type) {
+	case USB_ENDPOINT_XFER_INT:
+		ep_cfg = EPX_CON_TYPE_INT;
+		break;
+	case USB_ENDPOINT_XFER_BULK:
+		ep_cfg = EPX_CON_TYPE_BULK;
+		break;
+	default:
+		mult = USB_EP_MAXP_MULT(pep->endpoint.desc->wMaxPacketSize);
+		ep_cfg = mult << EPX_CON_ISOD_SHIFT;
+		ep_cfg |= EPX_CON_TYPE_ISOC;
+
+		if (pep->dir) {
+			set_reg_bit_8(&pdev->epx_regs->isoautoarm, BIT(pep->num));
+			set_reg_bit_8(&pdev->epx_regs->isoautodump, BIT(pep->num));
+			set_reg_bit_8(&pdev->epx_regs->isodctrl, BIT(pep->num));
+		}
+	}
+
+	switch (pdev->gadget.speed) {
+	case USB_SPEED_FULL:
+		max_packet_size = is_iso_ep ? 1023 : 64;
+		break;
+	case USB_SPEED_HIGH:
+		max_packet_size = is_iso_ep ? 1024 : 512;
+		break;
+	default:
+		/* All other speed are not supported. */
+		return -EINVAL;
+	}
+
+	ep_cfg |= (EPX_CON_VAL | (pep->buffering - 1));
+
+	if (pep->dir) {
+		dir = FIFOCTRL_IO_TX;
+		writew(max_packet_size, &pdev->epx_regs->txmaxpack[pep->num - 1]);
+		writeb(ep_cfg, &pdev->epx_regs->ep[pep->num - 1].txcon);
+	} else {
+		writew(max_packet_size, &pdev->epx_regs->rxmaxpack[pep->num - 1]);
+		writeb(ep_cfg, &pdev->epx_regs->ep[pep->num - 1].rxcon);
+	}
+
+	writeb(pep->num | dir | FIFOCTRL_FIFOAUTO,
+	       &pdev->usb_regs->fifoctrl);
+	writeb(pep->num | dir, &pdev->epx_regs->endprst);
+	writeb(pep->num | ENDPRST_FIFORST | ENDPRST_TOGRST | dir,
+	       &pdev->epx_regs->endprst);
+
+	if (max_packet_size == 1024)
+		pep->trb_burst_size = 128;
+	else if (max_packet_size >= 512)
+		pep->trb_burst_size = 64;
+	else
+		pep->trb_burst_size = 16;
+
+	cdns2_select_ep(pdev, pep->num | pep->dir);
+	writel(DMA_EP_CMD_EPRST | DMA_EP_CMD_DFLUSH, &pdev->adma_regs->ep_cmd);
+
+	ret = readl_poll_timeout_atomic(&pdev->adma_regs->ep_cmd, val,
+					!(val & (DMA_EP_CMD_DFLUSH |
+					DMA_EP_CMD_EPRST)),
+					1, 1000);
+
+	if (ret)
+		return ret;
+
+	writel(DMA_EP_STS_TRBERR | DMA_EP_STS_ISOERR, &pdev->adma_regs->ep_sts_en);
+
+	if (enable)
+		writel(DMA_EP_CFG_ENABLE, &pdev->adma_regs->ep_cfg);
+
+	trace_cdns2_epx_hw_cfg(pdev, pep);
+
+	dev_dbg(pdev->dev, "Configure %s: with MPS: %08x, ep con: %02x\n",
+		pep->name, max_packet_size, ep_cfg);
+
+	return 0;
+}
+
+struct usb_request *cdns2_gadget_ep_alloc_request(struct usb_ep *ep,
+						  gfp_t gfp_flags)
+{
+	struct cdns2_endpoint *pep = ep_to_cdns2_ep(ep);
+	struct cdns2_request *preq;
+
+	preq = kzalloc(sizeof(*preq), gfp_flags);
+	if (!preq)
+		return NULL;
+
+	preq->pep = pep;
+
+	trace_cdns2_alloc_request(preq);
+
+	return &preq->request;
+}
+
+void cdns2_gadget_ep_free_request(struct usb_ep *ep,
+				  struct usb_request *request)
+{
+	struct cdns2_request *preq = to_cdns2_request(request);
+
+	trace_cdns2_free_request(preq);
+	kfree(preq);
+}
+
+static int cdns2_gadget_ep_enable(struct usb_ep *ep,
+				  const struct usb_endpoint_descriptor *desc)
+{
+	u32 reg = DMA_EP_STS_EN_TRBERREN;
+	struct cdns2_endpoint *pep;
+	struct cdns2_device *pdev;
+	unsigned long flags;
+	int enable = 1;
+	int ret = 0;
+
+	if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT ||
+	    !desc->wMaxPacketSize) {
+		return -EINVAL;
+	}
+
+	pep = ep_to_cdns2_ep(ep);
+	pdev = pep->pdev;
+
+	if (dev_WARN_ONCE(pdev->dev, pep->ep_state & EP_ENABLED,
+			  "%s is already enabled\n", pep->name))
+		return 0;
+
+	spin_lock_irqsave(&pdev->lock, flags);
+
+	pep->type = usb_endpoint_type(desc);
+	pep->interval = desc->bInterval ? BIT(desc->bInterval - 1) : 0;
+
+	if (pdev->gadget.speed == USB_SPEED_FULL)
+		if (pep->type == USB_ENDPOINT_XFER_INT)
+			pep->interval = desc->bInterval;
+
+	if (pep->interval > ISO_MAX_INTERVAL &&
+	    pep->type == USB_ENDPOINT_XFER_ISOC) {
+		dev_err(pdev->dev, "ISO period is limited to %d (current: %d)\n",
+			ISO_MAX_INTERVAL, pep->interval);
+
+		ret =  -EINVAL;
+		goto exit;
+	}
+
+	/*
+	 * During ISO OUT traffic DMA reads Transfer Ring for the EP which has
+	 * never got doorbell.
+	 * This issue was detected only on simulation, but to avoid this issue
+	 * driver add protection against it. To fix it driver enable ISO OUT
+	 * endpoint before setting DRBL. This special treatment of ISO OUT
+	 * endpoints are recommended by controller specification.
+	 */
+	if (pep->type == USB_ENDPOINT_XFER_ISOC  && !pep->dir)
+		enable = 0;
+
+	ret = cdns2_alloc_tr_segment(pep);
+	if (ret)
+		goto exit;
+
+	ret = cdns2_ep_config(pep, enable);
+	if (ret) {
+		cdns2_free_tr_segment(pep);
+		ret =  -EINVAL;
+		goto exit;
+	}
+
+	trace_cdns2_gadget_ep_enable(pep);
+
+	pep->ep_state &= ~(EP_STALLED | EP_STALL_PENDING);
+	pep->ep_state |= EP_ENABLED;
+	pep->wa1_set = 0;
+	pep->ring.enqueue = 0;
+	pep->ring.dequeue = 0;
+	reg = readl(&pdev->adma_regs->ep_sts);
+	pep->ring.pcs = !!DMA_EP_STS_CCS(reg);
+	pep->ring.ccs = !!DMA_EP_STS_CCS(reg);
+
+	writel(pep->ring.dma, &pdev->adma_regs->ep_traddr);
+
+	/* one TRB is reserved for link TRB used in DMULT mode*/
+	pep->ring.free_trbs = TRBS_PER_SEGMENT - 1;
+
+exit:
+	spin_unlock_irqrestore(&pdev->lock, flags);
+
+	return ret;
+}
+
+static int cdns2_gadget_ep_disable(struct usb_ep *ep)
+{
+	struct cdns2_endpoint *pep;
+	struct cdns2_request *preq;
+	struct cdns2_device *pdev;
+	unsigned long flags;
+	int val;
+
+	if (!ep)
+		return -EINVAL;
+
+	pep = ep_to_cdns2_ep(ep);
+	pdev = pep->pdev;
+
+	if (dev_WARN_ONCE(pdev->dev, !(pep->ep_state & EP_ENABLED),
+			  "%s is already disabled\n", pep->name))
+		return 0;
+
+	spin_lock_irqsave(&pdev->lock, flags);
+
+	trace_cdns2_gadget_ep_disable(pep);
+
+	cdns2_select_ep(pdev, ep->desc->bEndpointAddress);
+
+	clear_reg_bit_32(&pdev->adma_regs->ep_cfg, DMA_EP_CFG_ENABLE);
+
+	/*
+	 * Driver needs some time before resetting endpoint.
+	 * It need waits for clearing DBUSY bit or for timeout expired.
+	 * 10us is enough time for controller to stop transfer.
+	 */
+	readl_poll_timeout_atomic(&pdev->adma_regs->ep_sts, val,
+				  !(val & DMA_EP_STS_DBUSY), 1, 10);
+	writel(DMA_EP_CMD_EPRST, &pdev->adma_regs->ep_cmd);
+
+	readl_poll_timeout_atomic(&pdev->adma_regs->ep_cmd, val,
+				  !(val & (DMA_EP_CMD_DFLUSH | DMA_EP_CMD_EPRST)),
+				  1, 1000);
+
+	while (!list_empty(&pep->pending_list)) {
+		preq = cdns2_next_preq(&pep->pending_list);
+		cdns2_gadget_giveback(pep, preq, -ESHUTDOWN);
+	}
+
+	while (!list_empty(&pep->deferred_list)) {
+		preq = cdns2_next_preq(&pep->deferred_list);
+		cdns2_gadget_giveback(pep, preq, -ESHUTDOWN);
+	}
+
+	ep->desc = NULL;
+	pep->ep_state &= ~EP_ENABLED;
+
+	spin_unlock_irqrestore(&pdev->lock, flags);
+
+	return 0;
+}
+
+static int cdns2_ep_enqueue(struct cdns2_endpoint *pep,
+			    struct cdns2_request *preq,
+			    gfp_t gfp_flags)
+{
+	struct cdns2_device *pdev = pep->pdev;
+	struct usb_request *request;
+	int ret;
+
+	request = &preq->request;
+	request->actual = 0;
+	request->status = -EINPROGRESS;
+
+	ret = usb_gadget_map_request_by_dev(pdev->dev, request, pep->dir);
+	if (ret) {
+		trace_cdns2_request_enqueue_error(preq);
+		return ret;
+	}
+
+	list_add_tail(&preq->list, &pep->deferred_list);
+	trace_cdns2_request_enqueue(preq);
+
+	if (!(pep->ep_state & EP_STALLED) && !(pep->ep_state & EP_STALL_PENDING))
+		cdns2_start_all_request(pdev, pep);
+
+	return 0;
+}
+
+static int cdns2_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
+				 gfp_t gfp_flags)
+{
+	struct usb_request *zlp_request;
+	struct cdns2_request *preq;
+	struct cdns2_endpoint *pep;
+	struct cdns2_device *pdev;
+	unsigned long flags;
+	int ret;
+
+	if (!request || !ep)
+		return -EINVAL;
+
+	pep = ep_to_cdns2_ep(ep);
+	pdev = pep->pdev;
+
+	if (!(pep->ep_state & EP_ENABLED)) {
+		dev_err(pdev->dev, "%s: can't queue to disabled endpoint\n",
+			pep->name);
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&pdev->lock, flags);
+
+	preq =  to_cdns2_request(request);
+	ret = cdns2_ep_enqueue(pep, preq, gfp_flags);
+
+	if (ret == 0 && request->zero && request->length &&
+	    (request->length % ep->maxpacket == 0)) {
+		struct cdns2_request *preq;
+
+		zlp_request = cdns2_gadget_ep_alloc_request(ep, GFP_ATOMIC);
+		zlp_request->buf = pdev->zlp_buf;
+		zlp_request->length = 0;
+
+		preq = to_cdns2_request(zlp_request);
+		ret = cdns2_ep_enqueue(pep, preq, gfp_flags);
+	}
+
+	spin_unlock_irqrestore(&pdev->lock, flags);
+	return ret;
+}
+
+int cdns2_gadget_ep_dequeue(struct usb_ep *ep,
+			    struct usb_request *request)
+{
+	struct cdns2_request *preq, *preq_temp, *cur_preq;
+	struct cdns2_endpoint *pep;
+	struct cdns2_trb *link_trb;
+	u8 req_on_hw_ring = 0;
+	unsigned long flags;
+	u32 buffer;
+	int val, i;
+
+	if (!ep || !request || !ep->desc)
+		return -EINVAL;
+
+	pep = ep_to_cdns2_ep(ep);
+	if (!pep->endpoint.desc) {
+		dev_err(pep->pdev->dev, "%s: can't dequeue to disabled endpoint\n",
+			pep->name);
+		return -ESHUTDOWN;
+	}
+
+	/* Requests has been dequeued during disabling endpoint. */
+	if (!(pep->ep_state & EP_ENABLED))
+		return 0;
+
+	spin_lock_irqsave(&pep->pdev->lock, flags);
+
+	cur_preq = to_cdns2_request(request);
+	trace_cdns2_request_dequeue(cur_preq);
+
+	list_for_each_entry_safe(preq, preq_temp, &pep->pending_list, list) {
+		if (cur_preq == preq) {
+			req_on_hw_ring = 1;
+			goto found;
+		}
+	}
+
+	list_for_each_entry_safe(preq, preq_temp, &pep->deferred_list, list) {
+		if (cur_preq == preq)
+			goto found;
+	}
+
+	goto not_found;
+
+found:
+	link_trb = preq->trb;
+
+	/* Update ring only if removed request is on pending_req_list list. */
+	if (req_on_hw_ring && link_trb) {
+		/* Stop DMA */
+		writel(DMA_EP_CMD_DFLUSH, &pep->pdev->adma_regs->ep_cmd);
+
+		/* Wait for DFLUSH cleared. */
+		readl_poll_timeout_atomic(&pep->pdev->adma_regs->ep_cmd, val,
+					  !(val & DMA_EP_CMD_DFLUSH), 1, 1000);
+
+		buffer = cpu_to_le32(TRB_BUFFER(pep->ring.dma +
+				    ((preq->end_trb + 1) * TRB_SIZE)));
+
+		for (i = 0; i < preq->num_of_trb; i++) {
+			link_trb->buffer = buffer;
+			link_trb->control = cpu_to_le32((le32_to_cpu(link_trb->control)
+					    & TRB_CYCLE) | TRB_CHAIN |
+					    TRB_TYPE(TRB_LINK));
+
+			trace_cdns2_queue_trb(pep, link_trb);
+			link_trb = cdns2_next_trb(pep, link_trb);
+		}
+
+		if (pep->wa1_trb == preq->trb)
+			cdns2_wa1_restore_cycle_bit(pep);
+	}
+
+	cdns2_gadget_giveback(pep, cur_preq, -ECONNRESET);
+
+	preq = cdns2_next_preq(&pep->pending_list);
+	if (preq)
+		cdns2_rearm_transfer(pep, 1);
+
+not_found:
+	spin_unlock_irqrestore(&pep->pdev->lock, flags);
+	return 0;
+}
+
+int cdns2_halt_endpoint(struct cdns2_device *pdev,
+			struct cdns2_endpoint *pep,
+			int value)
+{
+	u8 __iomem *conf;
+	int dir = 0;
+
+	if (!(pep->ep_state & EP_ENABLED))
+		return -EPERM;
+
+	if (pep->dir) {
+		dir = ENDPRST_IO_TX;
+		conf = &pdev->epx_regs->ep[pep->num - 1].txcon;
+	} else {
+		conf = &pdev->epx_regs->ep[pep->num - 1].rxcon;
+	}
+
+	if (!value) {
+		struct cdns2_trb *trb = NULL;
+		struct cdns2_request *preq;
+		struct cdns2_trb trb_tmp;
+
+		preq = cdns2_next_preq(&pep->pending_list);
+		if (preq) {
+			trb = preq->trb;
+			if (trb) {
+				trb_tmp = *trb;
+				trb->control = trb->control ^ cpu_to_le32(TRB_CYCLE);
+			}
+		}
+
+		trace_cdns2_ep_halt(pep, 0, 0);
+
+		/* Resets Sequence Number */
+		writeb(dir | pep->num, &pdev->epx_regs->endprst);
+		writeb(dir | ENDPRST_TOGRST | pep->num,
+		       &pdev->epx_regs->endprst);
+
+		clear_reg_bit_8(conf, EPX_CON_STALL);
+
+		pep->ep_state &= ~(EP_STALLED | EP_STALL_PENDING);
+
+		if (preq) {
+			if (trb)
+				*trb = trb_tmp;
+
+			cdns2_rearm_transfer(pep, 1);
+		}
+
+		cdns2_start_all_request(pdev, pep);
+	} else {
+		trace_cdns2_ep_halt(pep, 1, 0);
+		set_reg_bit_8(conf, EPX_CON_STALL);
+		writeb(dir | pep->num, &pdev->epx_regs->endprst);
+		writeb(dir | ENDPRST_FIFORST | pep->num,
+		       &pdev->epx_regs->endprst);
+		pep->ep_state |= EP_STALLED;
+	}
+
+	return 0;
+}
+
+/* Sets/clears stall on selected endpoint. */
+static int cdns2_gadget_ep_set_halt(struct usb_ep *ep, int value)
+{
+	struct cdns2_endpoint *pep = ep_to_cdns2_ep(ep);
+	struct cdns2_device *pdev = pep->pdev;
+	struct cdns2_request *preq;
+	unsigned long flags = 0;
+	int ret;
+
+	spin_lock_irqsave(&pdev->lock, flags);
+
+	preq = cdns2_next_preq(&pep->pending_list);
+	if (value && preq) {
+		trace_cdns2_ep_busy_try_halt_again(pep);
+		ret = -EAGAIN;
+		goto done;
+	}
+
+	if (!value)
+		pep->ep_state &= ~EP_WEDGE;
+
+	ret = cdns2_halt_endpoint(pdev, pep, value);
+
+done:
+	spin_unlock_irqrestore(&pdev->lock, flags);
+	return ret;
+}
+
+static int cdns2_gadget_ep_set_wedge(struct usb_ep *ep)
+{
+	struct cdns2_endpoint *pep = ep_to_cdns2_ep(ep);
+
+	cdns2_gadget_ep_set_halt(ep, 1);
+	pep->ep_state |= EP_WEDGE;
+
+	return 0;
+}
+
+static struct
+cdns2_endpoint *cdns2_find_available_ep(struct cdns2_device *pdev,
+					struct usb_endpoint_descriptor *desc)
+{
+	struct cdns2_endpoint *pep;
+	struct usb_ep *ep;
+	int ep_correct;
+
+	list_for_each_entry(ep, &pdev->gadget.ep_list, ep_list) {
+		unsigned long num;
+		int ret;
+		/* ep name pattern likes epXin or epXout. */
+		char c[2] = {ep->name[2], '\0'};
+
+		ret = kstrtoul(c, 10, &num);
+		if (ret)
+			return ERR_PTR(ret);
+		pep = ep_to_cdns2_ep(ep);
+
+		if (pep->num != num)
+			continue;
+
+		ep_correct = (pep->endpoint.caps.dir_in &&
+			      usb_endpoint_dir_in(desc)) ||
+			     (pep->endpoint.caps.dir_out &&
+			      usb_endpoint_dir_out(desc));
+
+		if (ep_correct && !(pep->ep_state & EP_CLAIMED))
+			return pep;
+	}
+
+	return ERR_PTR(-ENOENT);
+}
+
+/*
+ * Function used to recognize which endpoints will be used to optimize
+ * on-chip memory usage.
+ */
+static struct
+usb_ep *cdns2_gadget_match_ep(struct usb_gadget *gadget,
+			      struct usb_endpoint_descriptor *desc,
+			      struct usb_ss_ep_comp_descriptor *comp_desc)
+{
+	struct cdns2_device *pdev = gadget_to_cdns2_device(gadget);
+	struct cdns2_endpoint *pep;
+	unsigned long flags;
+
+	pep = cdns2_find_available_ep(pdev, desc);
+	if (IS_ERR(pep)) {
+		dev_err(pdev->dev, "no available ep\n");
+		return NULL;
+	}
+
+	spin_lock_irqsave(&pdev->lock, flags);
+
+	if (usb_endpoint_type(desc) == USB_ENDPOINT_XFER_ISOC)
+		pep->buffering = 4;
+	else
+		pep->buffering = 1;
+
+	pep->ep_state |= EP_CLAIMED;
+	spin_unlock_irqrestore(&pdev->lock, flags);
+
+	return &pep->endpoint;
+}
+
+static const struct usb_ep_ops cdns2_gadget_ep_ops = {
+	.enable = cdns2_gadget_ep_enable,
+	.disable = cdns2_gadget_ep_disable,
+	.alloc_request = cdns2_gadget_ep_alloc_request,
+	.free_request = cdns2_gadget_ep_free_request,
+	.queue = cdns2_gadget_ep_queue,
+	.dequeue = cdns2_gadget_ep_dequeue,
+	.set_halt = cdns2_gadget_ep_set_halt,
+	.set_wedge = cdns2_gadget_ep_set_wedge,
+};
+
+static int cdns2_gadget_get_frame(struct usb_gadget *gadget)
+{
+	struct cdns2_device *pdev = gadget_to_cdns2_device(gadget);
+
+	return readw(&pdev->usb_regs->frmnr);
+}
+
+static int cdns2_gadget_wakeup(struct usb_gadget *gadget)
+{
+	struct cdns2_device *pdev = gadget_to_cdns2_device(gadget);
+	unsigned long flags;
+
+	spin_lock_irqsave(&pdev->lock, flags);
+	cdns2_wakeup(pdev);
+	spin_unlock_irqrestore(&pdev->lock, flags);
+
+	return 0;
+}
+
+static int cdns2_gadget_set_selfpowered(struct usb_gadget *gadget,
+					int is_selfpowered)
+{
+	struct cdns2_device *pdev = gadget_to_cdns2_device(gadget);
+	unsigned long flags;
+
+	spin_lock_irqsave(&pdev->lock, flags);
+	pdev->is_selfpowered = !!is_selfpowered;
+	spin_unlock_irqrestore(&pdev->lock, flags);
+	return 0;
+}
+
+/*  Disable interrupts and begin the controller halting process. */
+static void cdns2_quiesce(struct cdns2_device *pdev)
+{
+	set_reg_bit_8(&pdev->usb_regs->usbcs, USBCS_DISCON);
+
+	/* Disable interrupt. */
+	writeb(0, &pdev->interrupt_regs->extien),
+	writeb(0, &pdev->interrupt_regs->usbien),
+	writew(0, &pdev->adma_regs->ep_ien);
+
+	/* Clear interrupt line. */
+	writeb(0x0, &pdev->interrupt_regs->usbirq);
+}
+
+static void cdns2_gadget_config(struct cdns2_device *pdev)
+{
+	cdns2_ep0_config(pdev);
+
+	/* Enable DMA interrupts for all endpoints. */
+	writel(~0x0, &pdev->adma_regs->ep_ien);
+	cdns2_enable_l1(pdev, 0);
+	writeb(USB_IEN_INIT, &pdev->interrupt_regs->usbien);
+	writeb(EXTIRQ_WAKEUP, &pdev->interrupt_regs->extien);
+	writel(DMA_CONF_DMULT, &pdev->adma_regs->conf);
+}
+
+static int cdns2_gadget_pullup(struct usb_gadget *gadget, int is_on)
+{
+	struct cdns2_device *pdev = gadget_to_cdns2_device(gadget);
+	unsigned long flags;
+
+	trace_cdns2_pullup(is_on);
+
+	/*
+	 * Disable events handling while controller is being
+	 * enabled/disabled.
+	 */
+	disable_irq(pdev->irq);
+	spin_lock_irqsave(&pdev->lock, flags);
+
+	if (is_on) {
+		cdns2_gadget_config(pdev);
+		clear_reg_bit_8(&pdev->usb_regs->usbcs, USBCS_DISCON);
+	} else {
+		cdns2_quiesce(pdev);
+	}
+
+	spin_unlock_irqrestore(&pdev->lock, flags);
+	enable_irq(pdev->irq);
+
+	return 0;
+}
+
+static int cdns2_gadget_udc_start(struct usb_gadget *gadget,
+				  struct usb_gadget_driver *driver)
+{
+	struct cdns2_device *pdev = gadget_to_cdns2_device(gadget);
+	enum usb_device_speed max_speed = driver->max_speed;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pdev->lock, flags);
+	pdev->gadget_driver = driver;
+
+	/* Limit speed if necessary. */
+	max_speed = min(driver->max_speed, gadget->max_speed);
+
+	switch (max_speed) {
+	case USB_SPEED_FULL:
+		writeb(SPEEDCTRL_HSDISABLE, &pdev->usb_regs->speedctrl);
+		break;
+	case USB_SPEED_HIGH:
+		writeb(0, &pdev->usb_regs->speedctrl);
+		break;
+	default:
+		dev_err(pdev->dev, "invalid maximum_speed parameter %d\n",
+			max_speed);
+		fallthrough;
+	case USB_SPEED_UNKNOWN:
+		/* Default to highspeed. */
+		max_speed = USB_SPEED_HIGH;
+		break;
+	}
+
+	/* Reset all USB endpoints. */
+	writeb(ENDPRST_IO_TX, &pdev->usb_regs->endprst);
+	writeb(ENDPRST_FIFORST | ENDPRST_TOGRST | ENDPRST_IO_TX,
+	       &pdev->usb_regs->endprst);
+	writeb(ENDPRST_FIFORST | ENDPRST_TOGRST, &pdev->usb_regs->endprst);
+
+	cdns2_eps_onchip_buffer_init(pdev);
+
+	cdns2_gadget_config(pdev);
+	spin_unlock_irqrestore(&pdev->lock, flags);
+
+	return 0;
+}
+
+static int cdns2_gadget_udc_stop(struct usb_gadget *gadget)
+{
+	struct cdns2_device *pdev = gadget_to_cdns2_device(gadget);
+	struct cdns2_endpoint *pep;
+	u32 bEndpointAddress;
+	struct usb_ep *ep;
+	int val;
+
+	pdev->gadget_driver = NULL;
+	pdev->gadget.speed = USB_SPEED_UNKNOWN;
+
+	list_for_each_entry(ep, &pdev->gadget.ep_list, ep_list) {
+		pep = ep_to_cdns2_ep(ep);
+		bEndpointAddress = pep->num | pep->dir;
+		cdns2_select_ep(pdev, bEndpointAddress);
+		writel(DMA_EP_CMD_EPRST, &pdev->adma_regs->ep_cmd);
+		readl_poll_timeout_atomic(&pdev->adma_regs->ep_cmd, val,
+					  !(val & DMA_EP_CMD_EPRST), 1, 100);
+	}
+
+	cdns2_quiesce(pdev);
+
+	writeb(ENDPRST_IO_TX, &pdev->usb_regs->endprst);
+	writeb(ENDPRST_FIFORST | ENDPRST_TOGRST | ENDPRST_IO_TX,
+	       &pdev->epx_regs->endprst);
+	writeb(ENDPRST_FIFORST | ENDPRST_TOGRST, &pdev->epx_regs->endprst);
+
+	return 0;
+}
+
+static const struct usb_gadget_ops cdns2_gadget_ops = {
+	.get_frame = cdns2_gadget_get_frame,
+	.wakeup = cdns2_gadget_wakeup,
+	.set_selfpowered = cdns2_gadget_set_selfpowered,
+	.pullup = cdns2_gadget_pullup,
+	.udc_start = cdns2_gadget_udc_start,
+	.udc_stop = cdns2_gadget_udc_stop,
+	.match_ep = cdns2_gadget_match_ep,
+};
+
+static void cdns2_free_all_eps(struct cdns2_device *pdev)
+{
+	int i;
+
+	for (i = 0; i < CDNS2_ENDPOINTS_NUM; i++)
+		cdns2_free_tr_segment(&pdev->eps[i]);
+}
+
+/* Initializes software endpoints of gadget. */
+static int cdns2_init_eps(struct cdns2_device *pdev)
+{
+	struct cdns2_endpoint *pep;
+	int i;
+
+	for (i = 0; i < CDNS2_ENDPOINTS_NUM; i++) {
+		bool direction = !(i & 1); /* Start from OUT endpoint. */
+		u8 epnum = ((i + 1) >> 1);
+
+		/*
+		 * Endpoints are being held in pdev->eps[] in form:
+		 * ep0, ep1out, ep1in ... ep15out, ep15in.
+		 */
+		if (!CDNS2_IF_EP_EXIST(pdev, epnum, direction))
+			continue;
+
+		pep = &pdev->eps[i];
+		pep->pdev = pdev;
+		pep->num = epnum;
+		/* 0 for OUT, 1 for IN. */
+		pep->dir = direction ? USB_DIR_IN : USB_DIR_OUT;
+		pep->idx = i;
+
+		/* Ep0in and ep0out are represented by pdev->eps[0]. */
+		if (!epnum) {
+			int ret;
+
+			snprintf(pep->name, sizeof(pep->name), "ep%d%s",
+				 epnum, "BiDir");
+
+			cdns2_init_ep0(pdev, pep);
+
+			ret = cdns2_alloc_tr_segment(pep);
+			if (ret) {
+				dev_err(pdev->dev, "Failed to init ep0\n");
+				return ret;
+			}
+		} else {
+			snprintf(pep->name, sizeof(pep->name), "ep%d%s",
+				 epnum, !!direction ? "in" : "out");
+			pep->endpoint.name = pep->name;
+
+			usb_ep_set_maxpacket_limit(&pep->endpoint, 1024);
+			pep->endpoint.ops = &cdns2_gadget_ep_ops;
+			list_add_tail(&pep->endpoint.ep_list, &pdev->gadget.ep_list);
+
+			pep->endpoint.caps.dir_in = direction;
+			pep->endpoint.caps.dir_out = !direction;
+
+			pep->endpoint.caps.type_iso = 1;
+			pep->endpoint.caps.type_bulk = 1;
+			pep->endpoint.caps.type_int = 1;
+		}
+
+		pep->endpoint.name = pep->name;
+		pep->ep_state = 0;
+
+		dev_dbg(pdev->dev, "Init %s, SupType: CTRL: %s, INT: %s, "
+			"BULK: %s, ISOC %s, SupDir IN: %s, OUT: %s\n",
+			pep->name,
+			(pep->endpoint.caps.type_control) ? "yes" : "no",
+			(pep->endpoint.caps.type_int) ? "yes" : "no",
+			(pep->endpoint.caps.type_bulk) ? "yes" : "no",
+			(pep->endpoint.caps.type_iso) ? "yes" : "no",
+			(pep->endpoint.caps.dir_in) ? "yes" : "no",
+			(pep->endpoint.caps.dir_out) ? "yes" : "no");
+
+		INIT_LIST_HEAD(&pep->pending_list);
+		INIT_LIST_HEAD(&pep->deferred_list);
+	}
+
+	return 0;
+}
+
+static int cdns2_gadget_start(struct cdns2_device *pdev)
+{
+	u32 max_speed;
+	void *buf;
+	int val;
+	int ret;
+
+	pdev->usb_regs = pdev->regs;
+	pdev->ep0_regs = pdev->regs;
+	pdev->epx_regs = pdev->regs;
+	pdev->interrupt_regs = pdev->regs;
+	pdev->adma_regs = pdev->regs + CDNS2_ADMA_REGS_OFFSET;
+
+	/* Reset controller. */
+	set_reg_bit_8(&pdev->usb_regs->cpuctrl, CPUCTRL_SW_RST);
+
+	ret = readl_poll_timeout_atomic(&pdev->usb_regs->cpuctrl, val,
+					!(val & CPUCTRL_SW_RST), 1, 10000);
+	if (ret) {
+		dev_err(pdev->dev, "Error: reset controller timeout\n");
+		return -EINVAL;
+	}
+
+	usb_initialize_gadget(pdev->dev, &pdev->gadget, NULL);
+
+	device_property_read_u16(pdev->dev, "cdns,on-chip-tx-buff-size",
+				 &pdev->onchip_tx_buf);
+	device_property_read_u16(pdev->dev, "cdns,on-chip-rx-buff-size",
+				 &pdev->onchip_rx_buf);
+	device_property_read_u32(pdev->dev, "cdns,avail-endpoints",
+				 &pdev->eps_supported);
+
+	/*
+	 * Driver assumes that each USBHS controller has at least
+	 * one IN and one OUT non control endpoint.
+	 */
+	if (!pdev->onchip_tx_buf && !pdev->onchip_rx_buf) {
+		ret = -EINVAL;
+		dev_err(pdev->dev, "Invalid on-chip memory configuration\n");
+		goto put_gadget;
+	}
+
+	if (!(pdev->eps_supported & ~0x00010001)) {
+		ret = -EINVAL;
+		dev_err(pdev->dev, "No hardware endpoints available\n");
+		goto put_gadget;
+	}
+
+	max_speed = usb_get_maximum_speed(pdev->dev);
+
+	switch (max_speed) {
+	case USB_SPEED_FULL:
+	case USB_SPEED_HIGH:
+		break;
+	default:
+		dev_err(pdev->dev, "invalid maximum_speed parameter %d\n",
+			max_speed);
+		fallthrough;
+	case USB_SPEED_UNKNOWN:
+		max_speed = USB_SPEED_HIGH;
+		break;
+	}
+
+	pdev->gadget.max_speed = max_speed;
+	pdev->gadget.speed = USB_SPEED_UNKNOWN;
+	pdev->gadget.ops = &cdns2_gadget_ops;
+	pdev->gadget.name = "usbhs-gadget";
+	pdev->gadget.quirk_avoids_skb_reserve = 1;
+	pdev->gadget.irq = pdev->irq;
+
+	spin_lock_init(&pdev->lock);
+	INIT_WORK(&pdev->pending_status_wq, cdns2_pending_setup_status_handler);
+
+	/* Initialize endpoint container. */
+	INIT_LIST_HEAD(&pdev->gadget.ep_list);
+	pdev->eps_dma_pool = dma_pool_create("cdns2_eps_dma_pool", pdev->dev,
+					     TR_SEG_SIZE, 8, 0);
+	if (!pdev->eps_dma_pool) {
+		dev_err(pdev->dev, "Failed to create TRB dma pool\n");
+		ret = -ENOMEM;
+		goto put_gadget;
+	}
+
+	ret = cdns2_init_eps(pdev);
+	if (ret) {
+		dev_err(pdev->dev, "Failed to create endpoints\n");
+		goto destroy_dma_pool;
+	}
+
+	pdev->gadget.sg_supported = 1;
+
+	pdev->zlp_buf = kzalloc(CDNS2_EP_ZLP_BUF_SIZE, GFP_KERNEL);
+	if (!pdev->zlp_buf) {
+		ret = -ENOMEM;
+		goto destroy_dma_pool;
+	}
+
+	/* Allocate memory for setup packet buffer. */
+	buf = dma_alloc_coherent(pdev->dev, 8, &pdev->ep0_preq.request.dma,
+				 GFP_DMA);
+	pdev->ep0_preq.request.buf = buf;
+
+	if (!pdev->ep0_preq.request.buf) {
+		ret = -ENOMEM;
+		goto free_zlp_buf;
+	}
+
+	/* Add USB gadget device. */
+	ret = usb_add_gadget(&pdev->gadget);
+	if (ret < 0) {
+		dev_err(pdev->dev, "Failed to add gadget\n");
+		goto free_ep0_buf;
+	}
+
+	return 0;
+
+free_ep0_buf:
+	dma_free_coherent(pdev->dev, 8, pdev->ep0_preq.request.buf,
+			  pdev->ep0_preq.request.dma);
+free_zlp_buf:
+	kfree(pdev->zlp_buf);
+destroy_dma_pool:
+	dma_pool_destroy(pdev->eps_dma_pool);
+put_gadget:
+	usb_put_gadget(&pdev->gadget);
+
+	return ret;
+}
+
+int cdns2_gadget_suspend(struct cdns2_device *pdev)
+{
+	unsigned long flags;
+
+	cdns2_disconnect_gadget(pdev);
+
+	spin_lock_irqsave(&pdev->lock, flags);
+	pdev->gadget.speed = USB_SPEED_UNKNOWN;
+
+	trace_cdns2_device_state("notattached");
+	usb_gadget_set_state(&pdev->gadget, USB_STATE_NOTATTACHED);
+	cdns2_enable_l1(pdev, 0);
+
+	/* Disable interrupt for device. */
+	writeb(0, &pdev->interrupt_regs->usbien);
+	writel(0, &pdev->adma_regs->ep_ien);
+	spin_unlock_irqrestore(&pdev->lock, flags);
+
+	return 0;
+}
+
+int cdns2_gadget_resume(struct cdns2_device *pdev, bool hibernated)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&pdev->lock, flags);
+
+	if (!pdev->gadget_driver) {
+		spin_unlock_irqrestore(&pdev->lock, flags);
+		return 0;
+	}
+
+	cdns2_gadget_config(pdev);
+
+	if (hibernated)
+		clear_reg_bit_8(&pdev->usb_regs->usbcs, USBCS_DISCON);
+
+	spin_unlock_irqrestore(&pdev->lock, flags);
+
+	return 0;
+}
+
+void cdns2_gadget_remove(struct cdns2_device *pdev)
+{
+	pm_runtime_mark_last_busy(pdev->dev);
+	pm_runtime_put_autosuspend(pdev->dev);
+
+	usb_del_gadget(&pdev->gadget);
+	cdns2_free_all_eps(pdev);
+
+	dma_pool_destroy(pdev->eps_dma_pool);
+	kfree(pdev->zlp_buf);
+	usb_put_gadget(&pdev->gadget);
+}
+
+int cdns2_gadget_init(struct cdns2_device *pdev)
+{
+	int ret;
+
+	/* Ensure 32-bit DMA Mask. */
+	ret = dma_set_mask_and_coherent(pdev->dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(pdev->dev, "Failed to set dma mask: %d\n", ret);
+		return ret;
+	}
+
+	pm_runtime_get_sync(pdev->dev);
+
+	cdsn2_isoc_burst_opt(pdev);
+
+	ret = cdns2_gadget_start(pdev);
+	if (ret) {
+		pm_runtime_put_sync(pdev->dev);
+		return ret;
+	}
+
+	/*
+	 * Because interrupt line can be shared with other components in
+	 * driver it can't use IRQF_ONESHOT flag here.
+	 */
+	ret = devm_request_threaded_irq(pdev->dev, pdev->irq,
+					cdns2_usb_irq_handler,
+					cdns2_thread_irq_handler,
+					IRQF_SHARED,
+					dev_name(pdev->dev),
+					pdev);
+	if (ret)
+		goto err0;
+
+	return 0;
+
+err0:
+	cdns2_gadget_remove(pdev);
+
+	return ret;
+}