Adding upstream version 5.10.209.upstream/5.10.209upstream

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

1 files changed, 2184 insertions, 0 deletions

diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
new file mode 100644
index 000000000..67d8da048
--- /dev/null
+++ b/drivers/usb/chipidea/udc.c
@@ -0,0 +1,2184 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * udc.c - ChipIdea UDC driver
+ *
+ * Copyright (C) 2008 Chipidea - MIPS Technologies, Inc. All rights reserved.
+ *
+ * Author: David Lopo
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dmapool.h>
+#include <linux/err.h>
+#include <linux/irqreturn.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/pm_runtime.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb/otg-fsm.h>
+#include <linux/usb/chipidea.h>
+
+#include "ci.h"
+#include "udc.h"
+#include "bits.h"
+#include "otg.h"
+#include "otg_fsm.h"
+
+/* control endpoint description */
+static const struct usb_endpoint_descriptor
+ctrl_endpt_out_desc = {
+	.bLength         = USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType = USB_DT_ENDPOINT,
+
+	.bEndpointAddress = USB_DIR_OUT,
+	.bmAttributes    = USB_ENDPOINT_XFER_CONTROL,
+	.wMaxPacketSize  = cpu_to_le16(CTRL_PAYLOAD_MAX),
+};
+
+static const struct usb_endpoint_descriptor
+ctrl_endpt_in_desc = {
+	.bLength         = USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType = USB_DT_ENDPOINT,
+
+	.bEndpointAddress = USB_DIR_IN,
+	.bmAttributes    = USB_ENDPOINT_XFER_CONTROL,
+	.wMaxPacketSize  = cpu_to_le16(CTRL_PAYLOAD_MAX),
+};
+
+/**
+ * hw_ep_bit: calculates the bit number
+ * @num: endpoint number
+ * @dir: endpoint direction
+ *
+ * This function returns bit number
+ */
+static inline int hw_ep_bit(int num, int dir)
+{
+	return num + ((dir == TX) ? 16 : 0);
+}
+
+static inline int ep_to_bit(struct ci_hdrc *ci, int n)
+{
+	int fill = 16 - ci->hw_ep_max / 2;
+
+	if (n >= ci->hw_ep_max / 2)
+		n += fill;
+
+	return n;
+}
+
+/**
+ * hw_device_state: enables/disables interrupts (execute without interruption)
+ * @ci: the controller
+ * @dma: 0 => disable, !0 => enable and set dma engine
+ *
+ * This function returns an error code
+ */
+static int hw_device_state(struct ci_hdrc *ci, u32 dma)
+{
+	if (dma) {
+		hw_write(ci, OP_ENDPTLISTADDR, ~0, dma);
+		/* interrupt, error, port change, reset, sleep/suspend */
+		hw_write(ci, OP_USBINTR, ~0,
+			     USBi_UI|USBi_UEI|USBi_PCI|USBi_URI|USBi_SLI);
+	} else {
+		hw_write(ci, OP_USBINTR, ~0, 0);
+	}
+	return 0;
+}
+
+/**
+ * hw_ep_flush: flush endpoint fifo (execute without interruption)
+ * @ci: the controller
+ * @num: endpoint number
+ * @dir: endpoint direction
+ *
+ * This function returns an error code
+ */
+static int hw_ep_flush(struct ci_hdrc *ci, int num, int dir)
+{
+	int n = hw_ep_bit(num, dir);
+
+	do {
+		/* flush any pending transfer */
+		hw_write(ci, OP_ENDPTFLUSH, ~0, BIT(n));
+		while (hw_read(ci, OP_ENDPTFLUSH, BIT(n)))
+			cpu_relax();
+	} while (hw_read(ci, OP_ENDPTSTAT, BIT(n)));
+
+	return 0;
+}
+
+/**
+ * hw_ep_disable: disables endpoint (execute without interruption)
+ * @ci: the controller
+ * @num: endpoint number
+ * @dir: endpoint direction
+ *
+ * This function returns an error code
+ */
+static int hw_ep_disable(struct ci_hdrc *ci, int num, int dir)
+{
+	hw_write(ci, OP_ENDPTCTRL + num,
+		 (dir == TX) ? ENDPTCTRL_TXE : ENDPTCTRL_RXE, 0);
+	return 0;
+}
+
+/**
+ * hw_ep_enable: enables endpoint (execute without interruption)
+ * @ci: the controller
+ * @num:  endpoint number
+ * @dir:  endpoint direction
+ * @type: endpoint type
+ *
+ * This function returns an error code
+ */
+static int hw_ep_enable(struct ci_hdrc *ci, int num, int dir, int type)
+{
+	u32 mask, data;
+
+	if (dir == TX) {
+		mask  = ENDPTCTRL_TXT;  /* type    */
+		data  = type << __ffs(mask);
+
+		mask |= ENDPTCTRL_TXS;  /* unstall */
+		mask |= ENDPTCTRL_TXR;  /* reset data toggle */
+		data |= ENDPTCTRL_TXR;
+		mask |= ENDPTCTRL_TXE;  /* enable  */
+		data |= ENDPTCTRL_TXE;
+	} else {
+		mask  = ENDPTCTRL_RXT;  /* type    */
+		data  = type << __ffs(mask);
+
+		mask |= ENDPTCTRL_RXS;  /* unstall */
+		mask |= ENDPTCTRL_RXR;  /* reset data toggle */
+		data |= ENDPTCTRL_RXR;
+		mask |= ENDPTCTRL_RXE;  /* enable  */
+		data |= ENDPTCTRL_RXE;
+	}
+	hw_write(ci, OP_ENDPTCTRL + num, mask, data);
+	return 0;
+}
+
+/**
+ * hw_ep_get_halt: return endpoint halt status
+ * @ci: the controller
+ * @num: endpoint number
+ * @dir: endpoint direction
+ *
+ * This function returns 1 if endpoint halted
+ */
+static int hw_ep_get_halt(struct ci_hdrc *ci, int num, int dir)
+{
+	u32 mask = (dir == TX) ? ENDPTCTRL_TXS : ENDPTCTRL_RXS;
+
+	return hw_read(ci, OP_ENDPTCTRL + num, mask) ? 1 : 0;
+}
+
+/**
+ * hw_ep_prime: primes endpoint (execute without interruption)
+ * @ci: the controller
+ * @num:     endpoint number
+ * @dir:     endpoint direction
+ * @is_ctrl: true if control endpoint
+ *
+ * This function returns an error code
+ */
+static int hw_ep_prime(struct ci_hdrc *ci, int num, int dir, int is_ctrl)
+{
+	int n = hw_ep_bit(num, dir);
+
+	/* Synchronize before ep prime */
+	wmb();
+
+	if (is_ctrl && dir == RX && hw_read(ci, OP_ENDPTSETUPSTAT, BIT(num)))
+		return -EAGAIN;
+
+	hw_write(ci, OP_ENDPTPRIME, ~0, BIT(n));
+
+	while (hw_read(ci, OP_ENDPTPRIME, BIT(n)))
+		cpu_relax();
+	if (is_ctrl && dir == RX && hw_read(ci, OP_ENDPTSETUPSTAT, BIT(num)))
+		return -EAGAIN;
+
+	/* status shoult be tested according with manual but it doesn't work */
+	return 0;
+}
+
+/**
+ * hw_ep_set_halt: configures ep halt & resets data toggle after clear (execute
+ *                 without interruption)
+ * @ci: the controller
+ * @num:   endpoint number
+ * @dir:   endpoint direction
+ * @value: true => stall, false => unstall
+ *
+ * This function returns an error code
+ */
+static int hw_ep_set_halt(struct ci_hdrc *ci, int num, int dir, int value)
+{
+	if (value != 0 && value != 1)
+		return -EINVAL;
+
+	do {
+		enum ci_hw_regs reg = OP_ENDPTCTRL + num;
+		u32 mask_xs = (dir == TX) ? ENDPTCTRL_TXS : ENDPTCTRL_RXS;
+		u32 mask_xr = (dir == TX) ? ENDPTCTRL_TXR : ENDPTCTRL_RXR;
+
+		/* data toggle - reserved for EP0 but it's in ESS */
+		hw_write(ci, reg, mask_xs|mask_xr,
+			  value ? mask_xs : mask_xr);
+	} while (value != hw_ep_get_halt(ci, num, dir));
+
+	return 0;
+}
+
+/**
+ * hw_is_port_high_speed: test if port is high speed
+ * @ci: the controller
+ *
+ * This function returns true if high speed port
+ */
+static int hw_port_is_high_speed(struct ci_hdrc *ci)
+{
+	return ci->hw_bank.lpm ? hw_read(ci, OP_DEVLC, DEVLC_PSPD) :
+		hw_read(ci, OP_PORTSC, PORTSC_HSP);
+}
+
+/**
+ * hw_test_and_clear_complete: test & clear complete status (execute without
+ *                             interruption)
+ * @ci: the controller
+ * @n: endpoint number
+ *
+ * This function returns complete status
+ */
+static int hw_test_and_clear_complete(struct ci_hdrc *ci, int n)
+{
+	n = ep_to_bit(ci, n);
+	return hw_test_and_clear(ci, OP_ENDPTCOMPLETE, BIT(n));
+}
+
+/**
+ * hw_test_and_clear_intr_active: test & clear active interrupts (execute
+ *                                without interruption)
+ * @ci: the controller
+ *
+ * This function returns active interrutps
+ */
+static u32 hw_test_and_clear_intr_active(struct ci_hdrc *ci)
+{
+	u32 reg = hw_read_intr_status(ci) & hw_read_intr_enable(ci);
+
+	hw_write(ci, OP_USBSTS, ~0, reg);
+	return reg;
+}
+
+/**
+ * hw_test_and_clear_setup_guard: test & clear setup guard (execute without
+ *                                interruption)
+ * @ci: the controller
+ *
+ * This function returns guard value
+ */
+static int hw_test_and_clear_setup_guard(struct ci_hdrc *ci)
+{
+	return hw_test_and_write(ci, OP_USBCMD, USBCMD_SUTW, 0);
+}
+
+/**
+ * hw_test_and_set_setup_guard: test & set setup guard (execute without
+ *                              interruption)
+ * @ci: the controller
+ *
+ * This function returns guard value
+ */
+static int hw_test_and_set_setup_guard(struct ci_hdrc *ci)
+{
+	return hw_test_and_write(ci, OP_USBCMD, USBCMD_SUTW, USBCMD_SUTW);
+}
+
+/**
+ * hw_usb_set_address: configures USB address (execute without interruption)
+ * @ci: the controller
+ * @value: new USB address
+ *
+ * This function explicitly sets the address, without the "USBADRA" (advance)
+ * feature, which is not supported by older versions of the controller.
+ */
+static void hw_usb_set_address(struct ci_hdrc *ci, u8 value)
+{
+	hw_write(ci, OP_DEVICEADDR, DEVICEADDR_USBADR,
+		 value << __ffs(DEVICEADDR_USBADR));
+}
+
+/**
+ * hw_usb_reset: restart device after a bus reset (execute without
+ *               interruption)
+ * @ci: the controller
+ *
+ * This function returns an error code
+ */
+static int hw_usb_reset(struct ci_hdrc *ci)
+{
+	hw_usb_set_address(ci, 0);
+
+	/* ESS flushes only at end?!? */
+	hw_write(ci, OP_ENDPTFLUSH,    ~0, ~0);
+
+	/* clear setup token semaphores */
+	hw_write(ci, OP_ENDPTSETUPSTAT, 0,  0);
+
+	/* clear complete status */
+	hw_write(ci, OP_ENDPTCOMPLETE,  0,  0);
+
+	/* wait until all bits cleared */
+	while (hw_read(ci, OP_ENDPTPRIME, ~0))
+		udelay(10);             /* not RTOS friendly */
+
+	/* reset all endpoints ? */
+
+	/* reset internal status and wait for further instructions
+	   no need to verify the port reset status (ESS does it) */
+
+	return 0;
+}
+
+/******************************************************************************
+ * UTIL block
+ *****************************************************************************/
+
+static int add_td_to_list(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq,
+			unsigned int length, struct scatterlist *s)
+{
+	int i;
+	u32 temp;
+	struct td_node *lastnode, *node = kzalloc(sizeof(struct td_node),
+						  GFP_ATOMIC);
+
+	if (node == NULL)
+		return -ENOMEM;
+
+	node->ptr = dma_pool_zalloc(hwep->td_pool, GFP_ATOMIC, &node->dma);
+	if (node->ptr == NULL) {
+		kfree(node);
+		return -ENOMEM;
+	}
+
+	node->ptr->token = cpu_to_le32(length << __ffs(TD_TOTAL_BYTES));
+	node->ptr->token &= cpu_to_le32(TD_TOTAL_BYTES);
+	node->ptr->token |= cpu_to_le32(TD_STATUS_ACTIVE);
+	if (hwep->type == USB_ENDPOINT_XFER_ISOC && hwep->dir == TX) {
+		u32 mul = hwreq->req.length / hwep->ep.maxpacket;
+
+		if (hwreq->req.length == 0
+				|| hwreq->req.length % hwep->ep.maxpacket)
+			mul++;
+		node->ptr->token |= cpu_to_le32(mul << __ffs(TD_MULTO));
+	}
+
+	if (s) {
+		temp = (u32) (sg_dma_address(s) + hwreq->req.actual);
+		node->td_remaining_size = CI_MAX_BUF_SIZE - length;
+	} else {
+		temp = (u32) (hwreq->req.dma + hwreq->req.actual);
+	}
+
+	if (length) {
+		node->ptr->page[0] = cpu_to_le32(temp);
+		for (i = 1; i < TD_PAGE_COUNT; i++) {
+			u32 page = temp + i * CI_HDRC_PAGE_SIZE;
+			page &= ~TD_RESERVED_MASK;
+			node->ptr->page[i] = cpu_to_le32(page);
+		}
+	}
+
+	hwreq->req.actual += length;
+
+	if (!list_empty(&hwreq->tds)) {
+		/* get the last entry */
+		lastnode = list_entry(hwreq->tds.prev,
+				struct td_node, td);
+		lastnode->ptr->next = cpu_to_le32(node->dma);
+	}
+
+	INIT_LIST_HEAD(&node->td);
+	list_add_tail(&node->td, &hwreq->tds);
+
+	return 0;
+}
+
+/**
+ * _usb_addr: calculates endpoint address from direction & number
+ * @ep:  endpoint
+ */
+static inline u8 _usb_addr(struct ci_hw_ep *ep)
+{
+	return ((ep->dir == TX) ? USB_ENDPOINT_DIR_MASK : 0) | ep->num;
+}
+
+static int prepare_td_for_non_sg(struct ci_hw_ep *hwep,
+		struct ci_hw_req *hwreq)
+{
+	unsigned int rest = hwreq->req.length;
+	int pages = TD_PAGE_COUNT;
+	int ret = 0;
+
+	if (rest == 0) {
+		ret = add_td_to_list(hwep, hwreq, 0, NULL);
+		if (ret < 0)
+			return ret;
+	}
+
+	/*
+	 * The first buffer could be not page aligned.
+	 * In that case we have to span into one extra td.
+	 */
+	if (hwreq->req.dma % PAGE_SIZE)
+		pages--;
+
+	while (rest > 0) {
+		unsigned int count = min(hwreq->req.length - hwreq->req.actual,
+			(unsigned int)(pages * CI_HDRC_PAGE_SIZE));
+
+		ret = add_td_to_list(hwep, hwreq, count, NULL);
+		if (ret < 0)
+			return ret;
+
+		rest -= count;
+	}
+
+	if (hwreq->req.zero && hwreq->req.length && hwep->dir == TX
+	    && (hwreq->req.length % hwep->ep.maxpacket == 0)) {
+		ret = add_td_to_list(hwep, hwreq, 0, NULL);
+		if (ret < 0)
+			return ret;
+	}
+
+	return ret;
+}
+
+static int prepare_td_per_sg(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq,
+		struct scatterlist *s)
+{
+	unsigned int rest = sg_dma_len(s);
+	int ret = 0;
+
+	hwreq->req.actual = 0;
+	while (rest > 0) {
+		unsigned int count = min_t(unsigned int, rest,
+				CI_MAX_BUF_SIZE);
+
+		ret = add_td_to_list(hwep, hwreq, count, s);
+		if (ret < 0)
+			return ret;
+
+		rest -= count;
+	}
+
+	return ret;
+}
+
+static void ci_add_buffer_entry(struct td_node *node, struct scatterlist *s)
+{
+	int empty_td_slot_index = (CI_MAX_BUF_SIZE - node->td_remaining_size)
+			/ CI_HDRC_PAGE_SIZE;
+	int i;
+	u32 token;
+
+	token = le32_to_cpu(node->ptr->token) + (sg_dma_len(s) << __ffs(TD_TOTAL_BYTES));
+	node->ptr->token = cpu_to_le32(token);
+
+	for (i = empty_td_slot_index; i < TD_PAGE_COUNT; i++) {
+		u32 page = (u32) sg_dma_address(s) +
+			(i - empty_td_slot_index) * CI_HDRC_PAGE_SIZE;
+
+		page &= ~TD_RESERVED_MASK;
+		node->ptr->page[i] = cpu_to_le32(page);
+	}
+}
+
+static int prepare_td_for_sg(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq)
+{
+	struct usb_request *req = &hwreq->req;
+	struct scatterlist *s = req->sg;
+	int ret = 0, i = 0;
+	struct td_node *node = NULL;
+
+	if (!s || req->zero || req->length == 0) {
+		dev_err(hwep->ci->dev, "not supported operation for sg\n");
+		return -EINVAL;
+	}
+
+	while (i++ < req->num_mapped_sgs) {
+		if (sg_dma_address(s) % PAGE_SIZE) {
+			dev_err(hwep->ci->dev, "not page aligned sg buffer\n");
+			return -EINVAL;
+		}
+
+		if (node && (node->td_remaining_size >= sg_dma_len(s))) {
+			ci_add_buffer_entry(node, s);
+			node->td_remaining_size -= sg_dma_len(s);
+		} else {
+			ret = prepare_td_per_sg(hwep, hwreq, s);
+			if (ret)
+				return ret;
+
+			node = list_entry(hwreq->tds.prev,
+				struct td_node, td);
+		}
+
+		s = sg_next(s);
+	}
+
+	return ret;
+}
+
+/**
+ * _hardware_enqueue: configures a request at hardware level
+ * @hwep:   endpoint
+ * @hwreq:  request
+ *
+ * This function returns an error code
+ */
+static int _hardware_enqueue(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq)
+{
+	struct ci_hdrc *ci = hwep->ci;
+	int ret = 0;
+	struct td_node *firstnode, *lastnode;
+
+	/* don't queue twice */
+	if (hwreq->req.status == -EALREADY)
+		return -EALREADY;
+
+	hwreq->req.status = -EALREADY;
+
+	ret = usb_gadget_map_request_by_dev(ci->dev->parent,
+					    &hwreq->req, hwep->dir);
+	if (ret)
+		return ret;
+
+	if (hwreq->req.num_mapped_sgs)
+		ret = prepare_td_for_sg(hwep, hwreq);
+	else
+		ret = prepare_td_for_non_sg(hwep, hwreq);
+
+	if (ret)
+		return ret;
+
+	firstnode = list_first_entry(&hwreq->tds, struct td_node, td);
+
+	lastnode = list_entry(hwreq->tds.prev,
+		struct td_node, td);
+
+	lastnode->ptr->next = cpu_to_le32(TD_TERMINATE);
+	if (!hwreq->req.no_interrupt)
+		lastnode->ptr->token |= cpu_to_le32(TD_IOC);
+	wmb();
+
+	hwreq->req.actual = 0;
+	if (!list_empty(&hwep->qh.queue)) {
+		struct ci_hw_req *hwreqprev;
+		int n = hw_ep_bit(hwep->num, hwep->dir);
+		int tmp_stat;
+		struct td_node *prevlastnode;
+		u32 next = firstnode->dma & TD_ADDR_MASK;
+
+		hwreqprev = list_entry(hwep->qh.queue.prev,
+				struct ci_hw_req, queue);
+		prevlastnode = list_entry(hwreqprev->tds.prev,
+				struct td_node, td);
+
+		prevlastnode->ptr->next = cpu_to_le32(next);
+		wmb();
+		if (hw_read(ci, OP_ENDPTPRIME, BIT(n)))
+			goto done;
+		do {
+			hw_write(ci, OP_USBCMD, USBCMD_ATDTW, USBCMD_ATDTW);
+			tmp_stat = hw_read(ci, OP_ENDPTSTAT, BIT(n));
+		} while (!hw_read(ci, OP_USBCMD, USBCMD_ATDTW));
+		hw_write(ci, OP_USBCMD, USBCMD_ATDTW, 0);
+		if (tmp_stat)
+			goto done;
+	}
+
+	/*  QH configuration */
+	hwep->qh.ptr->td.next = cpu_to_le32(firstnode->dma);
+	hwep->qh.ptr->td.token &=
+		cpu_to_le32(~(TD_STATUS_HALTED|TD_STATUS_ACTIVE));
+
+	if (hwep->type == USB_ENDPOINT_XFER_ISOC && hwep->dir == RX) {
+		u32 mul = hwreq->req.length / hwep->ep.maxpacket;
+
+		if (hwreq->req.length == 0
+				|| hwreq->req.length % hwep->ep.maxpacket)
+			mul++;
+		hwep->qh.ptr->cap |= cpu_to_le32(mul << __ffs(QH_MULT));
+	}
+
+	ret = hw_ep_prime(ci, hwep->num, hwep->dir,
+			   hwep->type == USB_ENDPOINT_XFER_CONTROL);
+done:
+	return ret;
+}
+
+/**
+ * free_pending_td: remove a pending request for the endpoint
+ * @hwep: endpoint
+ */
+static void free_pending_td(struct ci_hw_ep *hwep)
+{
+	struct td_node *pending = hwep->pending_td;
+
+	dma_pool_free(hwep->td_pool, pending->ptr, pending->dma);
+	hwep->pending_td = NULL;
+	kfree(pending);
+}
+
+static int reprime_dtd(struct ci_hdrc *ci, struct ci_hw_ep *hwep,
+					   struct td_node *node)
+{
+	hwep->qh.ptr->td.next = cpu_to_le32(node->dma);
+	hwep->qh.ptr->td.token &=
+		cpu_to_le32(~(TD_STATUS_HALTED | TD_STATUS_ACTIVE));
+
+	return hw_ep_prime(ci, hwep->num, hwep->dir,
+				hwep->type == USB_ENDPOINT_XFER_CONTROL);
+}
+
+/**
+ * _hardware_dequeue: handles a request at hardware level
+ * @hwep: endpoint
+ * @hwreq:  request
+ *
+ * This function returns an error code
+ */
+static int _hardware_dequeue(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq)
+{
+	u32 tmptoken;
+	struct td_node *node, *tmpnode;
+	unsigned remaining_length;
+	unsigned actual = hwreq->req.length;
+	struct ci_hdrc *ci = hwep->ci;
+
+	if (hwreq->req.status != -EALREADY)
+		return -EINVAL;
+
+	hwreq->req.status = 0;
+
+	list_for_each_entry_safe(node, tmpnode, &hwreq->tds, td) {
+		tmptoken = le32_to_cpu(node->ptr->token);
+		if ((TD_STATUS_ACTIVE & tmptoken) != 0) {
+			int n = hw_ep_bit(hwep->num, hwep->dir);
+
+			if (ci->rev == CI_REVISION_24)
+				if (!hw_read(ci, OP_ENDPTSTAT, BIT(n)))
+					reprime_dtd(ci, hwep, node);
+			hwreq->req.status = -EALREADY;
+			return -EBUSY;
+		}
+
+		remaining_length = (tmptoken & TD_TOTAL_BYTES);
+		remaining_length >>= __ffs(TD_TOTAL_BYTES);
+		actual -= remaining_length;
+
+		hwreq->req.status = tmptoken & TD_STATUS;
+		if ((TD_STATUS_HALTED & hwreq->req.status)) {
+			hwreq->req.status = -EPIPE;
+			break;
+		} else if ((TD_STATUS_DT_ERR & hwreq->req.status)) {
+			hwreq->req.status = -EPROTO;
+			break;
+		} else if ((TD_STATUS_TR_ERR & hwreq->req.status)) {
+			hwreq->req.status = -EILSEQ;
+			break;
+		}
+
+		if (remaining_length) {
+			if (hwep->dir == TX) {
+				hwreq->req.status = -EPROTO;
+				break;
+			}
+		}
+		/*
+		 * As the hardware could still address the freed td
+		 * which will run the udc unusable, the cleanup of the
+		 * td has to be delayed by one.
+		 */
+		if (hwep->pending_td)
+			free_pending_td(hwep);
+
+		hwep->pending_td = node;
+		list_del_init(&node->td);
+	}
+
+	usb_gadget_unmap_request_by_dev(hwep->ci->dev->parent,
+					&hwreq->req, hwep->dir);
+
+	hwreq->req.actual += actual;
+
+	if (hwreq->req.status)
+		return hwreq->req.status;
+
+	return hwreq->req.actual;
+}
+
+/**
+ * _ep_nuke: dequeues all endpoint requests
+ * @hwep: endpoint
+ *
+ * This function returns an error code
+ * Caller must hold lock
+ */
+static int _ep_nuke(struct ci_hw_ep *hwep)
+__releases(hwep->lock)
+__acquires(hwep->lock)
+{
+	struct td_node *node, *tmpnode;
+	if (hwep == NULL)
+		return -EINVAL;
+
+	hw_ep_flush(hwep->ci, hwep->num, hwep->dir);
+
+	while (!list_empty(&hwep->qh.queue)) {
+
+		/* pop oldest request */
+		struct ci_hw_req *hwreq = list_entry(hwep->qh.queue.next,
+						     struct ci_hw_req, queue);
+
+		list_for_each_entry_safe(node, tmpnode, &hwreq->tds, td) {
+			dma_pool_free(hwep->td_pool, node->ptr, node->dma);
+			list_del_init(&node->td);
+			node->ptr = NULL;
+			kfree(node);
+		}
+
+		list_del_init(&hwreq->queue);
+		hwreq->req.status = -ESHUTDOWN;
+
+		if (hwreq->req.complete != NULL) {
+			spin_unlock(hwep->lock);
+			usb_gadget_giveback_request(&hwep->ep, &hwreq->req);
+			spin_lock(hwep->lock);
+		}
+	}
+
+	if (hwep->pending_td)
+		free_pending_td(hwep);
+
+	return 0;
+}
+
+static int _ep_set_halt(struct usb_ep *ep, int value, bool check_transfer)
+{
+	struct ci_hw_ep *hwep = container_of(ep, struct ci_hw_ep, ep);
+	int direction, retval = 0;
+	unsigned long flags;
+
+	if (ep == NULL || hwep->ep.desc == NULL)
+		return -EINVAL;
+
+	if (usb_endpoint_xfer_isoc(hwep->ep.desc))
+		return -EOPNOTSUPP;
+
+	spin_lock_irqsave(hwep->lock, flags);
+
+	if (value && hwep->dir == TX && check_transfer &&
+		!list_empty(&hwep->qh.queue) &&
+			!usb_endpoint_xfer_control(hwep->ep.desc)) {
+		spin_unlock_irqrestore(hwep->lock, flags);
+		return -EAGAIN;
+	}
+
+	direction = hwep->dir;
+	do {
+		retval |= hw_ep_set_halt(hwep->ci, hwep->num, hwep->dir, value);
+
+		if (!value)
+			hwep->wedge = 0;
+
+		if (hwep->type == USB_ENDPOINT_XFER_CONTROL)
+			hwep->dir = (hwep->dir == TX) ? RX : TX;
+
+	} while (hwep->dir != direction);
+
+	spin_unlock_irqrestore(hwep->lock, flags);
+	return retval;
+}
+
+
+/**
+ * _gadget_stop_activity: stops all USB activity, flushes & disables all endpts
+ * @gadget: gadget
+ *
+ * This function returns an error code
+ */
+static int _gadget_stop_activity(struct usb_gadget *gadget)
+{
+	struct usb_ep *ep;
+	struct ci_hdrc    *ci = container_of(gadget, struct ci_hdrc, gadget);
+	unsigned long flags;
+
+	/* flush all endpoints */
+	gadget_for_each_ep(ep, gadget) {
+		usb_ep_fifo_flush(ep);
+	}
+	usb_ep_fifo_flush(&ci->ep0out->ep);
+	usb_ep_fifo_flush(&ci->ep0in->ep);
+
+	/* make sure to disable all endpoints */
+	gadget_for_each_ep(ep, gadget) {
+		usb_ep_disable(ep);
+	}
+
+	if (ci->status != NULL) {
+		usb_ep_free_request(&ci->ep0in->ep, ci->status);
+		ci->status = NULL;
+	}
+
+	spin_lock_irqsave(&ci->lock, flags);
+	ci->gadget.speed = USB_SPEED_UNKNOWN;
+	ci->remote_wakeup = 0;
+	ci->suspended = 0;
+	spin_unlock_irqrestore(&ci->lock, flags);
+
+	return 0;
+}
+
+/******************************************************************************
+ * ISR block
+ *****************************************************************************/
+/**
+ * isr_reset_handler: USB reset interrupt handler
+ * @ci: UDC device
+ *
+ * This function resets USB engine after a bus reset occurred
+ */
+static void isr_reset_handler(struct ci_hdrc *ci)
+__releases(ci->lock)
+__acquires(ci->lock)
+{
+	int retval;
+
+	spin_unlock(&ci->lock);
+	if (ci->gadget.speed != USB_SPEED_UNKNOWN)
+		usb_gadget_udc_reset(&ci->gadget, ci->driver);
+
+	retval = _gadget_stop_activity(&ci->gadget);
+	if (retval)
+		goto done;
+
+	retval = hw_usb_reset(ci);
+	if (retval)
+		goto done;
+
+	ci->status = usb_ep_alloc_request(&ci->ep0in->ep, GFP_ATOMIC);
+	if (ci->status == NULL)
+		retval = -ENOMEM;
+
+done:
+	spin_lock(&ci->lock);
+
+	if (retval)
+		dev_err(ci->dev, "error: %i\n", retval);
+}
+
+/**
+ * isr_get_status_complete: get_status request complete function
+ * @ep:  endpoint
+ * @req: request handled
+ *
+ * Caller must release lock
+ */
+static void isr_get_status_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	if (ep == NULL || req == NULL)
+		return;
+
+	kfree(req->buf);
+	usb_ep_free_request(ep, req);
+}
+
+/**
+ * _ep_queue: queues (submits) an I/O request to an endpoint
+ * @ep:        endpoint
+ * @req:       request
+ * @gfp_flags: GFP flags (not used)
+ *
+ * Caller must hold lock
+ * This function returns an error code
+ */
+static int _ep_queue(struct usb_ep *ep, struct usb_request *req,
+		    gfp_t __maybe_unused gfp_flags)
+{
+	struct ci_hw_ep  *hwep  = container_of(ep,  struct ci_hw_ep, ep);
+	struct ci_hw_req *hwreq = container_of(req, struct ci_hw_req, req);
+	struct ci_hdrc *ci = hwep->ci;
+	int retval = 0;
+
+	if (ep == NULL || req == NULL || hwep->ep.desc == NULL)
+		return -EINVAL;
+
+	if (hwep->type == USB_ENDPOINT_XFER_CONTROL) {
+		if (req->length)
+			hwep = (ci->ep0_dir == RX) ?
+			       ci->ep0out : ci->ep0in;
+		if (!list_empty(&hwep->qh.queue)) {
+			_ep_nuke(hwep);
+			dev_warn(hwep->ci->dev, "endpoint ctrl %X nuked\n",
+				 _usb_addr(hwep));
+		}
+	}
+
+	if (usb_endpoint_xfer_isoc(hwep->ep.desc) &&
+	    hwreq->req.length > hwep->ep.mult * hwep->ep.maxpacket) {
+		dev_err(hwep->ci->dev, "request length too big for isochronous\n");
+		return -EMSGSIZE;
+	}
+
+	/* first nuke then test link, e.g. previous status has not sent */
+	if (!list_empty(&hwreq->queue)) {
+		dev_err(hwep->ci->dev, "request already in queue\n");
+		return -EBUSY;
+	}
+
+	/* push request */
+	hwreq->req.status = -EINPROGRESS;
+	hwreq->req.actual = 0;
+
+	retval = _hardware_enqueue(hwep, hwreq);
+
+	if (retval == -EALREADY)
+		retval = 0;
+	if (!retval)
+		list_add_tail(&hwreq->queue, &hwep->qh.queue);
+
+	return retval;
+}
+
+/**
+ * isr_get_status_response: get_status request response
+ * @ci: ci struct
+ * @setup: setup request packet
+ *
+ * This function returns an error code
+ */
+static int isr_get_status_response(struct ci_hdrc *ci,
+				   struct usb_ctrlrequest *setup)
+__releases(hwep->lock)
+__acquires(hwep->lock)
+{
+	struct ci_hw_ep *hwep = ci->ep0in;
+	struct usb_request *req = NULL;
+	gfp_t gfp_flags = GFP_ATOMIC;
+	int dir, num, retval;
+
+	if (hwep == NULL || setup == NULL)
+		return -EINVAL;
+
+	spin_unlock(hwep->lock);
+	req = usb_ep_alloc_request(&hwep->ep, gfp_flags);
+	spin_lock(hwep->lock);
+	if (req == NULL)
+		return -ENOMEM;
+
+	req->complete = isr_get_status_complete;
+	req->length   = 2;
+	req->buf      = kzalloc(req->length, gfp_flags);
+	if (req->buf == NULL) {
+		retval = -ENOMEM;
+		goto err_free_req;
+	}
+
+	if ((setup->bRequestType & USB_RECIP_MASK) == USB_RECIP_DEVICE) {
+		*(u16 *)req->buf = (ci->remote_wakeup << 1) |
+			ci->gadget.is_selfpowered;
+	} else if ((setup->bRequestType & USB_RECIP_MASK) \
+		   == USB_RECIP_ENDPOINT) {
+		dir = (le16_to_cpu(setup->wIndex) & USB_ENDPOINT_DIR_MASK) ?
+			TX : RX;
+		num =  le16_to_cpu(setup->wIndex) & USB_ENDPOINT_NUMBER_MASK;
+		*(u16 *)req->buf = hw_ep_get_halt(ci, num, dir);
+	}
+	/* else do nothing; reserved for future use */
+
+	retval = _ep_queue(&hwep->ep, req, gfp_flags);
+	if (retval)
+		goto err_free_buf;
+
+	return 0;
+
+ err_free_buf:
+	kfree(req->buf);
+ err_free_req:
+	spin_unlock(hwep->lock);
+	usb_ep_free_request(&hwep->ep, req);
+	spin_lock(hwep->lock);
+	return retval;
+}
+
+/**
+ * isr_setup_status_complete: setup_status request complete function
+ * @ep:  endpoint
+ * @req: request handled
+ *
+ * Caller must release lock. Put the port in test mode if test mode
+ * feature is selected.
+ */
+static void
+isr_setup_status_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct ci_hdrc *ci = req->context;
+	unsigned long flags;
+
+	if (req->status < 0)
+		return;
+
+	if (ci->setaddr) {
+		hw_usb_set_address(ci, ci->address);
+		ci->setaddr = false;
+		if (ci->address)
+			usb_gadget_set_state(&ci->gadget, USB_STATE_ADDRESS);
+	}
+
+	spin_lock_irqsave(&ci->lock, flags);
+	if (ci->test_mode)
+		hw_port_test_set(ci, ci->test_mode);
+	spin_unlock_irqrestore(&ci->lock, flags);
+}
+
+/**
+ * isr_setup_status_phase: queues the status phase of a setup transation
+ * @ci: ci struct
+ *
+ * This function returns an error code
+ */
+static int isr_setup_status_phase(struct ci_hdrc *ci)
+{
+	struct ci_hw_ep *hwep;
+
+	/*
+	 * Unexpected USB controller behavior, caused by bad signal integrity
+	 * or ground reference problems, can lead to isr_setup_status_phase
+	 * being called with ci->status equal to NULL.
+	 * If this situation occurs, you should review your USB hardware design.
+	 */
+	if (WARN_ON_ONCE(!ci->status))
+		return -EPIPE;
+
+	hwep = (ci->ep0_dir == TX) ? ci->ep0out : ci->ep0in;
+	ci->status->context = ci;
+	ci->status->complete = isr_setup_status_complete;
+
+	return _ep_queue(&hwep->ep, ci->status, GFP_ATOMIC);
+}
+
+/**
+ * isr_tr_complete_low: transaction complete low level handler
+ * @hwep: endpoint
+ *
+ * This function returns an error code
+ * Caller must hold lock
+ */
+static int isr_tr_complete_low(struct ci_hw_ep *hwep)
+__releases(hwep->lock)
+__acquires(hwep->lock)
+{
+	struct ci_hw_req *hwreq, *hwreqtemp;
+	struct ci_hw_ep *hweptemp = hwep;
+	int retval = 0;
+
+	list_for_each_entry_safe(hwreq, hwreqtemp, &hwep->qh.queue,
+			queue) {
+		retval = _hardware_dequeue(hwep, hwreq);
+		if (retval < 0)
+			break;
+		list_del_init(&hwreq->queue);
+		if (hwreq->req.complete != NULL) {
+			spin_unlock(hwep->lock);
+			if ((hwep->type == USB_ENDPOINT_XFER_CONTROL) &&
+					hwreq->req.length)
+				hweptemp = hwep->ci->ep0in;
+			usb_gadget_giveback_request(&hweptemp->ep, &hwreq->req);
+			spin_lock(hwep->lock);
+		}
+	}
+
+	if (retval == -EBUSY)
+		retval = 0;
+
+	return retval;
+}
+
+static int otg_a_alt_hnp_support(struct ci_hdrc *ci)
+{
+	dev_warn(&ci->gadget.dev,
+		"connect the device to an alternate port if you want HNP\n");
+	return isr_setup_status_phase(ci);
+}
+
+/**
+ * isr_setup_packet_handler: setup packet handler
+ * @ci: UDC descriptor
+ *
+ * This function handles setup packet 
+ */
+static void isr_setup_packet_handler(struct ci_hdrc *ci)
+__releases(ci->lock)
+__acquires(ci->lock)
+{
+	struct ci_hw_ep *hwep = &ci->ci_hw_ep[0];
+	struct usb_ctrlrequest req;
+	int type, num, dir, err = -EINVAL;
+	u8 tmode = 0;
+
+	/*
+	 * Flush data and handshake transactions of previous
+	 * setup packet.
+	 */
+	_ep_nuke(ci->ep0out);
+	_ep_nuke(ci->ep0in);
+
+	/* read_setup_packet */
+	do {
+		hw_test_and_set_setup_guard(ci);
+		memcpy(&req, &hwep->qh.ptr->setup, sizeof(req));
+	} while (!hw_test_and_clear_setup_guard(ci));
+
+	type = req.bRequestType;
+
+	ci->ep0_dir = (type & USB_DIR_IN) ? TX : RX;
+
+	switch (req.bRequest) {
+	case USB_REQ_CLEAR_FEATURE:
+		if (type == (USB_DIR_OUT|USB_RECIP_ENDPOINT) &&
+				le16_to_cpu(req.wValue) ==
+				USB_ENDPOINT_HALT) {
+			if (req.wLength != 0)
+				break;
+			num  = le16_to_cpu(req.wIndex);
+			dir = (num & USB_ENDPOINT_DIR_MASK) ? TX : RX;
+			num &= USB_ENDPOINT_NUMBER_MASK;
+			if (dir == TX)
+				num += ci->hw_ep_max / 2;
+			if (!ci->ci_hw_ep[num].wedge) {
+				spin_unlock(&ci->lock);
+				err = usb_ep_clear_halt(
+					&ci->ci_hw_ep[num].ep);
+				spin_lock(&ci->lock);
+				if (err)
+					break;
+			}
+			err = isr_setup_status_phase(ci);
+		} else if (type == (USB_DIR_OUT|USB_RECIP_DEVICE) &&
+				le16_to_cpu(req.wValue) ==
+				USB_DEVICE_REMOTE_WAKEUP) {
+			if (req.wLength != 0)
+				break;
+			ci->remote_wakeup = 0;
+			err = isr_setup_status_phase(ci);
+		} else {
+			goto delegate;
+		}
+		break;
+	case USB_REQ_GET_STATUS:
+		if ((type != (USB_DIR_IN|USB_RECIP_DEVICE) ||
+			le16_to_cpu(req.wIndex) == OTG_STS_SELECTOR) &&
+		    type != (USB_DIR_IN|USB_RECIP_ENDPOINT) &&
+		    type != (USB_DIR_IN|USB_RECIP_INTERFACE))
+			goto delegate;
+		if (le16_to_cpu(req.wLength) != 2 ||
+		    le16_to_cpu(req.wValue)  != 0)
+			break;
+		err = isr_get_status_response(ci, &req);
+		break;
+	case USB_REQ_SET_ADDRESS:
+		if (type != (USB_DIR_OUT|USB_RECIP_DEVICE))
+			goto delegate;
+		if (le16_to_cpu(req.wLength) != 0 ||
+		    le16_to_cpu(req.wIndex)  != 0)
+			break;
+		ci->address = (u8)le16_to_cpu(req.wValue);
+		ci->setaddr = true;
+		err = isr_setup_status_phase(ci);
+		break;
+	case USB_REQ_SET_FEATURE:
+		if (type == (USB_DIR_OUT|USB_RECIP_ENDPOINT) &&
+				le16_to_cpu(req.wValue) ==
+				USB_ENDPOINT_HALT) {
+			if (req.wLength != 0)
+				break;
+			num  = le16_to_cpu(req.wIndex);
+			dir = (num & USB_ENDPOINT_DIR_MASK) ? TX : RX;
+			num &= USB_ENDPOINT_NUMBER_MASK;
+			if (dir == TX)
+				num += ci->hw_ep_max / 2;
+
+			spin_unlock(&ci->lock);
+			err = _ep_set_halt(&ci->ci_hw_ep[num].ep, 1, false);
+			spin_lock(&ci->lock);
+			if (!err)
+				isr_setup_status_phase(ci);
+		} else if (type == (USB_DIR_OUT|USB_RECIP_DEVICE)) {
+			if (req.wLength != 0)
+				break;
+			switch (le16_to_cpu(req.wValue)) {
+			case USB_DEVICE_REMOTE_WAKEUP:
+				ci->remote_wakeup = 1;
+				err = isr_setup_status_phase(ci);
+				break;
+			case USB_DEVICE_TEST_MODE:
+				tmode = le16_to_cpu(req.wIndex) >> 8;
+				switch (tmode) {
+				case USB_TEST_J:
+				case USB_TEST_K:
+				case USB_TEST_SE0_NAK:
+				case USB_TEST_PACKET:
+				case USB_TEST_FORCE_ENABLE:
+					ci->test_mode = tmode;
+					err = isr_setup_status_phase(
+							ci);
+					break;
+				default:
+					break;
+				}
+				break;
+			case USB_DEVICE_B_HNP_ENABLE:
+				if (ci_otg_is_fsm_mode(ci)) {
+					ci->gadget.b_hnp_enable = 1;
+					err = isr_setup_status_phase(
+							ci);
+				}
+				break;
+			case USB_DEVICE_A_ALT_HNP_SUPPORT:
+				if (ci_otg_is_fsm_mode(ci))
+					err = otg_a_alt_hnp_support(ci);
+				break;
+			case USB_DEVICE_A_HNP_SUPPORT:
+				if (ci_otg_is_fsm_mode(ci)) {
+					ci->gadget.a_hnp_support = 1;
+					err = isr_setup_status_phase(
+							ci);
+				}
+				break;
+			default:
+				goto delegate;
+			}
+		} else {
+			goto delegate;
+		}
+		break;
+	default:
+delegate:
+		if (req.wLength == 0)   /* no data phase */
+			ci->ep0_dir = TX;
+
+		spin_unlock(&ci->lock);
+		err = ci->driver->setup(&ci->gadget, &req);
+		spin_lock(&ci->lock);
+		break;
+	}
+
+	if (err < 0) {
+		spin_unlock(&ci->lock);
+		if (_ep_set_halt(&hwep->ep, 1, false))
+			dev_err(ci->dev, "error: _ep_set_halt\n");
+		spin_lock(&ci->lock);
+	}
+}
+
+/**
+ * isr_tr_complete_handler: transaction complete interrupt handler
+ * @ci: UDC descriptor
+ *
+ * This function handles traffic events
+ */
+static void isr_tr_complete_handler(struct ci_hdrc *ci)
+__releases(ci->lock)
+__acquires(ci->lock)
+{
+	unsigned i;
+	int err;
+
+	for (i = 0; i < ci->hw_ep_max; i++) {
+		struct ci_hw_ep *hwep  = &ci->ci_hw_ep[i];
+
+		if (hwep->ep.desc == NULL)
+			continue;   /* not configured */
+
+		if (hw_test_and_clear_complete(ci, i)) {
+			err = isr_tr_complete_low(hwep);
+			if (hwep->type == USB_ENDPOINT_XFER_CONTROL) {
+				if (err > 0)   /* needs status phase */
+					err = isr_setup_status_phase(ci);
+				if (err < 0) {
+					spin_unlock(&ci->lock);
+					if (_ep_set_halt(&hwep->ep, 1, false))
+						dev_err(ci->dev,
+						"error: _ep_set_halt\n");
+					spin_lock(&ci->lock);
+				}
+			}
+		}
+
+		/* Only handle setup packet below */
+		if (i == 0 &&
+			hw_test_and_clear(ci, OP_ENDPTSETUPSTAT, BIT(0)))
+			isr_setup_packet_handler(ci);
+	}
+}
+
+/******************************************************************************
+ * ENDPT block
+ *****************************************************************************/
+/*
+ * ep_enable: configure endpoint, making it usable
+ *
+ * Check usb_ep_enable() at "usb_gadget.h" for details
+ */
+static int ep_enable(struct usb_ep *ep,
+		     const struct usb_endpoint_descriptor *desc)
+{
+	struct ci_hw_ep *hwep = container_of(ep, struct ci_hw_ep, ep);
+	int retval = 0;
+	unsigned long flags;
+	u32 cap = 0;
+
+	if (ep == NULL || desc == NULL)
+		return -EINVAL;
+
+	spin_lock_irqsave(hwep->lock, flags);
+
+	/* only internal SW should enable ctrl endpts */
+
+	if (!list_empty(&hwep->qh.queue)) {
+		dev_warn(hwep->ci->dev, "enabling a non-empty endpoint!\n");
+		spin_unlock_irqrestore(hwep->lock, flags);
+		return -EBUSY;
+	}
+
+	hwep->ep.desc = desc;
+
+	hwep->dir  = usb_endpoint_dir_in(desc) ? TX : RX;
+	hwep->num  = usb_endpoint_num(desc);
+	hwep->type = usb_endpoint_type(desc);
+
+	hwep->ep.maxpacket = usb_endpoint_maxp(desc);
+	hwep->ep.mult = usb_endpoint_maxp_mult(desc);
+
+	if (hwep->type == USB_ENDPOINT_XFER_CONTROL)
+		cap |= QH_IOS;
+
+	cap |= QH_ZLT;
+	cap |= (hwep->ep.maxpacket << __ffs(QH_MAX_PKT)) & QH_MAX_PKT;
+	/*
+	 * For ISO-TX, we set mult at QH as the largest value, and use
+	 * MultO at TD as real mult value.
+	 */
+	if (hwep->type == USB_ENDPOINT_XFER_ISOC && hwep->dir == TX)
+		cap |= 3 << __ffs(QH_MULT);
+
+	hwep->qh.ptr->cap = cpu_to_le32(cap);
+
+	hwep->qh.ptr->td.next |= cpu_to_le32(TD_TERMINATE);   /* needed? */
+
+	if (hwep->num != 0 && hwep->type == USB_ENDPOINT_XFER_CONTROL) {
+		dev_err(hwep->ci->dev, "Set control xfer at non-ep0\n");
+		retval = -EINVAL;
+	}
+
+	/*
+	 * Enable endpoints in the HW other than ep0 as ep0
+	 * is always enabled
+	 */
+	if (hwep->num)
+		retval |= hw_ep_enable(hwep->ci, hwep->num, hwep->dir,
+				       hwep->type);
+
+	spin_unlock_irqrestore(hwep->lock, flags);
+	return retval;
+}
+
+/*
+ * ep_disable: endpoint is no longer usable
+ *
+ * Check usb_ep_disable() at "usb_gadget.h" for details
+ */
+static int ep_disable(struct usb_ep *ep)
+{
+	struct ci_hw_ep *hwep = container_of(ep, struct ci_hw_ep, ep);
+	int direction, retval = 0;
+	unsigned long flags;
+
+	if (ep == NULL)
+		return -EINVAL;
+	else if (hwep->ep.desc == NULL)
+		return -EBUSY;
+
+	spin_lock_irqsave(hwep->lock, flags);
+	if (hwep->ci->gadget.speed == USB_SPEED_UNKNOWN) {
+		spin_unlock_irqrestore(hwep->lock, flags);
+		return 0;
+	}
+
+	/* only internal SW should disable ctrl endpts */
+
+	direction = hwep->dir;
+	do {
+		retval |= _ep_nuke(hwep);
+		retval |= hw_ep_disable(hwep->ci, hwep->num, hwep->dir);
+
+		if (hwep->type == USB_ENDPOINT_XFER_CONTROL)
+			hwep->dir = (hwep->dir == TX) ? RX : TX;
+
+	} while (hwep->dir != direction);
+
+	hwep->ep.desc = NULL;
+
+	spin_unlock_irqrestore(hwep->lock, flags);
+	return retval;
+}
+
+/*
+ * ep_alloc_request: allocate a request object to use with this endpoint
+ *
+ * Check usb_ep_alloc_request() at "usb_gadget.h" for details
+ */
+static struct usb_request *ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
+{
+	struct ci_hw_req *hwreq = NULL;
+
+	if (ep == NULL)
+		return NULL;
+
+	hwreq = kzalloc(sizeof(struct ci_hw_req), gfp_flags);
+	if (hwreq != NULL) {
+		INIT_LIST_HEAD(&hwreq->queue);
+		INIT_LIST_HEAD(&hwreq->tds);
+	}
+
+	return (hwreq == NULL) ? NULL : &hwreq->req;
+}
+
+/*
+ * ep_free_request: frees a request object
+ *
+ * Check usb_ep_free_request() at "usb_gadget.h" for details
+ */
+static void ep_free_request(struct usb_ep *ep, struct usb_request *req)
+{
+	struct ci_hw_ep  *hwep  = container_of(ep,  struct ci_hw_ep, ep);
+	struct ci_hw_req *hwreq = container_of(req, struct ci_hw_req, req);
+	struct td_node *node, *tmpnode;
+	unsigned long flags;
+
+	if (ep == NULL || req == NULL) {
+		return;
+	} else if (!list_empty(&hwreq->queue)) {
+		dev_err(hwep->ci->dev, "freeing queued request\n");
+		return;
+	}
+
+	spin_lock_irqsave(hwep->lock, flags);
+
+	list_for_each_entry_safe(node, tmpnode, &hwreq->tds, td) {
+		dma_pool_free(hwep->td_pool, node->ptr, node->dma);
+		list_del_init(&node->td);
+		node->ptr = NULL;
+		kfree(node);
+	}
+
+	kfree(hwreq);
+
+	spin_unlock_irqrestore(hwep->lock, flags);
+}
+
+/*
+ * ep_queue: queues (submits) an I/O request to an endpoint
+ *
+ * Check usb_ep_queue()* at usb_gadget.h" for details
+ */
+static int ep_queue(struct usb_ep *ep, struct usb_request *req,
+		    gfp_t __maybe_unused gfp_flags)
+{
+	struct ci_hw_ep  *hwep  = container_of(ep,  struct ci_hw_ep, ep);
+	int retval = 0;
+	unsigned long flags;
+
+	if (ep == NULL || req == NULL || hwep->ep.desc == NULL)
+		return -EINVAL;
+
+	spin_lock_irqsave(hwep->lock, flags);
+	if (hwep->ci->gadget.speed == USB_SPEED_UNKNOWN) {
+		spin_unlock_irqrestore(hwep->lock, flags);
+		return 0;
+	}
+	retval = _ep_queue(ep, req, gfp_flags);
+	spin_unlock_irqrestore(hwep->lock, flags);
+	return retval;
+}
+
+/*
+ * ep_dequeue: dequeues (cancels, unlinks) an I/O request from an endpoint
+ *
+ * Check usb_ep_dequeue() at "usb_gadget.h" for details
+ */
+static int ep_dequeue(struct usb_ep *ep, struct usb_request *req)
+{
+	struct ci_hw_ep  *hwep  = container_of(ep,  struct ci_hw_ep, ep);
+	struct ci_hw_req *hwreq = container_of(req, struct ci_hw_req, req);
+	unsigned long flags;
+	struct td_node *node, *tmpnode;
+
+	if (ep == NULL || req == NULL || hwreq->req.status != -EALREADY ||
+		hwep->ep.desc == NULL || list_empty(&hwreq->queue) ||
+		list_empty(&hwep->qh.queue))
+		return -EINVAL;
+
+	spin_lock_irqsave(hwep->lock, flags);
+	if (hwep->ci->gadget.speed != USB_SPEED_UNKNOWN)
+		hw_ep_flush(hwep->ci, hwep->num, hwep->dir);
+
+	list_for_each_entry_safe(node, tmpnode, &hwreq->tds, td) {
+		dma_pool_free(hwep->td_pool, node->ptr, node->dma);
+		list_del(&node->td);
+		kfree(node);
+	}
+
+	/* pop request */
+	list_del_init(&hwreq->queue);
+
+	usb_gadget_unmap_request(&hwep->ci->gadget, req, hwep->dir);
+
+	req->status = -ECONNRESET;
+
+	if (hwreq->req.complete != NULL) {
+		spin_unlock(hwep->lock);
+		usb_gadget_giveback_request(&hwep->ep, &hwreq->req);
+		spin_lock(hwep->lock);
+	}
+
+	spin_unlock_irqrestore(hwep->lock, flags);
+	return 0;
+}
+
+/*
+ * ep_set_halt: sets the endpoint halt feature
+ *
+ * Check usb_ep_set_halt() at "usb_gadget.h" for details
+ */
+static int ep_set_halt(struct usb_ep *ep, int value)
+{
+	return _ep_set_halt(ep, value, true);
+}
+
+/*
+ * ep_set_wedge: sets the halt feature and ignores clear requests
+ *
+ * Check usb_ep_set_wedge() at "usb_gadget.h" for details
+ */
+static int ep_set_wedge(struct usb_ep *ep)
+{
+	struct ci_hw_ep *hwep = container_of(ep, struct ci_hw_ep, ep);
+	unsigned long flags;
+
+	if (ep == NULL || hwep->ep.desc == NULL)
+		return -EINVAL;
+
+	spin_lock_irqsave(hwep->lock, flags);
+	hwep->wedge = 1;
+	spin_unlock_irqrestore(hwep->lock, flags);
+
+	return usb_ep_set_halt(ep);
+}
+
+/*
+ * ep_fifo_flush: flushes contents of a fifo
+ *
+ * Check usb_ep_fifo_flush() at "usb_gadget.h" for details
+ */
+static void ep_fifo_flush(struct usb_ep *ep)
+{
+	struct ci_hw_ep *hwep = container_of(ep, struct ci_hw_ep, ep);
+	unsigned long flags;
+
+	if (ep == NULL) {
+		dev_err(hwep->ci->dev, "%02X: -EINVAL\n", _usb_addr(hwep));
+		return;
+	}
+
+	spin_lock_irqsave(hwep->lock, flags);
+	if (hwep->ci->gadget.speed == USB_SPEED_UNKNOWN) {
+		spin_unlock_irqrestore(hwep->lock, flags);
+		return;
+	}
+
+	hw_ep_flush(hwep->ci, hwep->num, hwep->dir);
+
+	spin_unlock_irqrestore(hwep->lock, flags);
+}
+
+/*
+ * Endpoint-specific part of the API to the USB controller hardware
+ * Check "usb_gadget.h" for details
+ */
+static const struct usb_ep_ops usb_ep_ops = {
+	.enable	       = ep_enable,
+	.disable       = ep_disable,
+	.alloc_request = ep_alloc_request,
+	.free_request  = ep_free_request,
+	.queue	       = ep_queue,
+	.dequeue       = ep_dequeue,
+	.set_halt      = ep_set_halt,
+	.set_wedge     = ep_set_wedge,
+	.fifo_flush    = ep_fifo_flush,
+};
+
+/******************************************************************************
+ * GADGET block
+ *****************************************************************************/
+/*
+ * ci_hdrc_gadget_connect: caller makes sure gadget driver is binded
+ */
+static void ci_hdrc_gadget_connect(struct usb_gadget *_gadget, int is_active)
+{
+	struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
+
+	if (is_active) {
+		pm_runtime_get_sync(ci->dev);
+		hw_device_reset(ci);
+		spin_lock_irq(&ci->lock);
+		if (ci->driver) {
+			hw_device_state(ci, ci->ep0out->qh.dma);
+			usb_gadget_set_state(_gadget, USB_STATE_POWERED);
+			spin_unlock_irq(&ci->lock);
+			usb_udc_vbus_handler(_gadget, true);
+		} else {
+			spin_unlock_irq(&ci->lock);
+		}
+	} else {
+		usb_udc_vbus_handler(_gadget, false);
+		if (ci->driver)
+			ci->driver->disconnect(&ci->gadget);
+		hw_device_state(ci, 0);
+		if (ci->platdata->notify_event)
+			ci->platdata->notify_event(ci,
+			CI_HDRC_CONTROLLER_STOPPED_EVENT);
+		_gadget_stop_activity(&ci->gadget);
+		pm_runtime_put_sync(ci->dev);
+		usb_gadget_set_state(_gadget, USB_STATE_NOTATTACHED);
+	}
+}
+
+static int ci_udc_vbus_session(struct usb_gadget *_gadget, int is_active)
+{
+	struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&ci->lock, flags);
+	ci->vbus_active = is_active;
+	spin_unlock_irqrestore(&ci->lock, flags);
+
+	if (ci->usb_phy)
+		usb_phy_set_charger_state(ci->usb_phy, is_active ?
+			USB_CHARGER_PRESENT : USB_CHARGER_ABSENT);
+
+	if (ci->platdata->notify_event)
+		ret = ci->platdata->notify_event(ci,
+				CI_HDRC_CONTROLLER_VBUS_EVENT);
+
+	if (ci->driver)
+		ci_hdrc_gadget_connect(_gadget, is_active);
+
+	return ret;
+}
+
+static int ci_udc_wakeup(struct usb_gadget *_gadget)
+{
+	struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&ci->lock, flags);
+	if (ci->gadget.speed == USB_SPEED_UNKNOWN) {
+		spin_unlock_irqrestore(&ci->lock, flags);
+		return 0;
+	}
+	if (!ci->remote_wakeup) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+	if (!hw_read(ci, OP_PORTSC, PORTSC_SUSP)) {
+		ret = -EINVAL;
+		goto out;
+	}
+	hw_write(ci, OP_PORTSC, PORTSC_FPR, PORTSC_FPR);
+out:
+	spin_unlock_irqrestore(&ci->lock, flags);
+	return ret;
+}
+
+static int ci_udc_vbus_draw(struct usb_gadget *_gadget, unsigned ma)
+{
+	struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
+
+	if (ci->usb_phy)
+		return usb_phy_set_power(ci->usb_phy, ma);
+	return -ENOTSUPP;
+}
+
+static int ci_udc_selfpowered(struct usb_gadget *_gadget, int is_on)
+{
+	struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
+	struct ci_hw_ep *hwep = ci->ep0in;
+	unsigned long flags;
+
+	spin_lock_irqsave(hwep->lock, flags);
+	_gadget->is_selfpowered = (is_on != 0);
+	spin_unlock_irqrestore(hwep->lock, flags);
+
+	return 0;
+}
+
+/* Change Data+ pullup status
+ * this func is used by usb_gadget_connect/disconnect
+ */
+static int ci_udc_pullup(struct usb_gadget *_gadget, int is_on)
+{
+	struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
+
+	/*
+	 * Data+ pullup controlled by OTG state machine in OTG fsm mode;
+	 * and don't touch Data+ in host mode for dual role config.
+	 */
+	if (ci_otg_is_fsm_mode(ci) || ci->role == CI_ROLE_HOST)
+		return 0;
+
+	pm_runtime_get_sync(ci->dev);
+	if (is_on)
+		hw_write(ci, OP_USBCMD, USBCMD_RS, USBCMD_RS);
+	else
+		hw_write(ci, OP_USBCMD, USBCMD_RS, 0);
+	pm_runtime_put_sync(ci->dev);
+
+	return 0;
+}
+
+static int ci_udc_start(struct usb_gadget *gadget,
+			 struct usb_gadget_driver *driver);
+static int ci_udc_stop(struct usb_gadget *gadget);
+
+/* Match ISOC IN from the highest endpoint */
+static struct usb_ep *ci_udc_match_ep(struct usb_gadget *gadget,
+			      struct usb_endpoint_descriptor *desc,
+			      struct usb_ss_ep_comp_descriptor *comp_desc)
+{
+	struct ci_hdrc *ci = container_of(gadget, struct ci_hdrc, gadget);
+	struct usb_ep *ep;
+
+	if (usb_endpoint_xfer_isoc(desc) && usb_endpoint_dir_in(desc)) {
+		list_for_each_entry_reverse(ep, &ci->gadget.ep_list, ep_list) {
+			if (ep->caps.dir_in && !ep->claimed)
+				return ep;
+		}
+	}
+
+	return NULL;
+}
+
+/*
+ * Device operations part of the API to the USB controller hardware,
+ * which don't involve endpoints (or i/o)
+ * Check  "usb_gadget.h" for details
+ */
+static const struct usb_gadget_ops usb_gadget_ops = {
+	.vbus_session	= ci_udc_vbus_session,
+	.wakeup		= ci_udc_wakeup,
+	.set_selfpowered	= ci_udc_selfpowered,
+	.pullup		= ci_udc_pullup,
+	.vbus_draw	= ci_udc_vbus_draw,
+	.udc_start	= ci_udc_start,
+	.udc_stop	= ci_udc_stop,
+	.match_ep 	= ci_udc_match_ep,
+};
+
+static int init_eps(struct ci_hdrc *ci)
+{
+	int retval = 0, i, j;
+
+	for (i = 0; i < ci->hw_ep_max/2; i++)
+		for (j = RX; j <= TX; j++) {
+			int k = i + j * ci->hw_ep_max/2;
+			struct ci_hw_ep *hwep = &ci->ci_hw_ep[k];
+
+			scnprintf(hwep->name, sizeof(hwep->name), "ep%i%s", i,
+					(j == TX)  ? "in" : "out");
+
+			hwep->ci          = ci;
+			hwep->lock         = &ci->lock;
+			hwep->td_pool      = ci->td_pool;
+
+			hwep->ep.name      = hwep->name;
+			hwep->ep.ops       = &usb_ep_ops;
+
+			if (i == 0) {
+				hwep->ep.caps.type_control = true;
+			} else {
+				hwep->ep.caps.type_iso = true;
+				hwep->ep.caps.type_bulk = true;
+				hwep->ep.caps.type_int = true;
+			}
+
+			if (j == TX)
+				hwep->ep.caps.dir_in = true;
+			else
+				hwep->ep.caps.dir_out = true;
+
+			/*
+			 * for ep0: maxP defined in desc, for other
+			 * eps, maxP is set by epautoconfig() called
+			 * by gadget layer
+			 */
+			usb_ep_set_maxpacket_limit(&hwep->ep, (unsigned short)~0);
+
+			INIT_LIST_HEAD(&hwep->qh.queue);
+			hwep->qh.ptr = dma_pool_zalloc(ci->qh_pool, GFP_KERNEL,
+						       &hwep->qh.dma);
+			if (hwep->qh.ptr == NULL)
+				retval = -ENOMEM;
+
+			/*
+			 * set up shorthands for ep0 out and in endpoints,
+			 * don't add to gadget's ep_list
+			 */
+			if (i == 0) {
+				if (j == RX)
+					ci->ep0out = hwep;
+				else
+					ci->ep0in = hwep;
+
+				usb_ep_set_maxpacket_limit(&hwep->ep, CTRL_PAYLOAD_MAX);
+				continue;
+			}
+
+			list_add_tail(&hwep->ep.ep_list, &ci->gadget.ep_list);
+		}
+
+	return retval;
+}
+
+static void destroy_eps(struct ci_hdrc *ci)
+{
+	int i;
+
+	for (i = 0; i < ci->hw_ep_max; i++) {
+		struct ci_hw_ep *hwep = &ci->ci_hw_ep[i];
+
+		if (hwep->pending_td)
+			free_pending_td(hwep);
+		dma_pool_free(ci->qh_pool, hwep->qh.ptr, hwep->qh.dma);
+	}
+}
+
+/**
+ * ci_udc_start: register a gadget driver
+ * @gadget: our gadget
+ * @driver: the driver being registered
+ *
+ * Interrupts are enabled here.
+ */
+static int ci_udc_start(struct usb_gadget *gadget,
+			 struct usb_gadget_driver *driver)
+{
+	struct ci_hdrc *ci = container_of(gadget, struct ci_hdrc, gadget);
+	int retval;
+
+	if (driver->disconnect == NULL)
+		return -EINVAL;
+
+	ci->ep0out->ep.desc = &ctrl_endpt_out_desc;
+	retval = usb_ep_enable(&ci->ep0out->ep);
+	if (retval)
+		return retval;
+
+	ci->ep0in->ep.desc = &ctrl_endpt_in_desc;
+	retval = usb_ep_enable(&ci->ep0in->ep);
+	if (retval)
+		return retval;
+
+	ci->driver = driver;
+
+	/* Start otg fsm for B-device */
+	if (ci_otg_is_fsm_mode(ci) && ci->fsm.id) {
+		ci_hdrc_otg_fsm_start(ci);
+		return retval;
+	}
+
+	if (ci->vbus_active)
+		ci_hdrc_gadget_connect(gadget, 1);
+	else
+		usb_udc_vbus_handler(&ci->gadget, false);
+
+	return retval;
+}
+
+static void ci_udc_stop_for_otg_fsm(struct ci_hdrc *ci)
+{
+	if (!ci_otg_is_fsm_mode(ci))
+		return;
+
+	mutex_lock(&ci->fsm.lock);
+	if (ci->fsm.otg->state == OTG_STATE_A_PERIPHERAL) {
+		ci->fsm.a_bidl_adis_tmout = 1;
+		ci_hdrc_otg_fsm_start(ci);
+	} else if (ci->fsm.otg->state == OTG_STATE_B_PERIPHERAL) {
+		ci->fsm.protocol = PROTO_UNDEF;
+		ci->fsm.otg->state = OTG_STATE_UNDEFINED;
+	}
+	mutex_unlock(&ci->fsm.lock);
+}
+
+/*
+ * ci_udc_stop: unregister a gadget driver
+ */
+static int ci_udc_stop(struct usb_gadget *gadget)
+{
+	struct ci_hdrc *ci = container_of(gadget, struct ci_hdrc, gadget);
+	unsigned long flags;
+
+	spin_lock_irqsave(&ci->lock, flags);
+	ci->driver = NULL;
+
+	if (ci->vbus_active) {
+		hw_device_state(ci, 0);
+		spin_unlock_irqrestore(&ci->lock, flags);
+		if (ci->platdata->notify_event)
+			ci->platdata->notify_event(ci,
+			CI_HDRC_CONTROLLER_STOPPED_EVENT);
+		_gadget_stop_activity(&ci->gadget);
+		spin_lock_irqsave(&ci->lock, flags);
+		pm_runtime_put(ci->dev);
+	}
+
+	spin_unlock_irqrestore(&ci->lock, flags);
+
+	ci_udc_stop_for_otg_fsm(ci);
+	return 0;
+}
+
+/******************************************************************************
+ * BUS block
+ *****************************************************************************/
+/*
+ * udc_irq: ci interrupt handler
+ *
+ * This function returns IRQ_HANDLED if the IRQ has been handled
+ * It locks access to registers
+ */
+static irqreturn_t udc_irq(struct ci_hdrc *ci)
+{
+	irqreturn_t retval;
+	u32 intr;
+
+	if (ci == NULL)
+		return IRQ_HANDLED;
+
+	spin_lock(&ci->lock);
+
+	if (ci->platdata->flags & CI_HDRC_REGS_SHARED) {
+		if (hw_read(ci, OP_USBMODE, USBMODE_CM) !=
+				USBMODE_CM_DC) {
+			spin_unlock(&ci->lock);
+			return IRQ_NONE;
+		}
+	}
+	intr = hw_test_and_clear_intr_active(ci);
+
+	if (intr) {
+		/* order defines priority - do NOT change it */
+		if (USBi_URI & intr)
+			isr_reset_handler(ci);
+
+		if (USBi_PCI & intr) {
+			ci->gadget.speed = hw_port_is_high_speed(ci) ?
+				USB_SPEED_HIGH : USB_SPEED_FULL;
+			if (ci->suspended) {
+				if (ci->driver->resume) {
+					spin_unlock(&ci->lock);
+					ci->driver->resume(&ci->gadget);
+					spin_lock(&ci->lock);
+				}
+				ci->suspended = 0;
+				usb_gadget_set_state(&ci->gadget,
+						ci->resume_state);
+			}
+		}
+
+		if (USBi_UI  & intr)
+			isr_tr_complete_handler(ci);
+
+		if ((USBi_SLI & intr) && !(ci->suspended)) {
+			ci->suspended = 1;
+			ci->resume_state = ci->gadget.state;
+			if (ci->gadget.speed != USB_SPEED_UNKNOWN &&
+			    ci->driver->suspend) {
+				spin_unlock(&ci->lock);
+				ci->driver->suspend(&ci->gadget);
+				spin_lock(&ci->lock);
+			}
+			usb_gadget_set_state(&ci->gadget,
+					USB_STATE_SUSPENDED);
+		}
+		retval = IRQ_HANDLED;
+	} else {
+		retval = IRQ_NONE;
+	}
+	spin_unlock(&ci->lock);
+
+	return retval;
+}
+
+/**
+ * udc_start: initialize gadget role
+ * @ci: chipidea controller
+ */
+static int udc_start(struct ci_hdrc *ci)
+{
+	struct device *dev = ci->dev;
+	struct usb_otg_caps *otg_caps = &ci->platdata->ci_otg_caps;
+	int retval = 0;
+
+	ci->gadget.ops          = &usb_gadget_ops;
+	ci->gadget.speed        = USB_SPEED_UNKNOWN;
+	ci->gadget.max_speed    = USB_SPEED_HIGH;
+	ci->gadget.name         = ci->platdata->name;
+	ci->gadget.otg_caps	= otg_caps;
+	ci->gadget.sg_supported = 1;
+	ci->gadget.irq		= ci->irq;
+
+	if (ci->platdata->flags & CI_HDRC_REQUIRES_ALIGNED_DMA)
+		ci->gadget.quirk_avoids_skb_reserve = 1;
+
+	if (ci->is_otg && (otg_caps->hnp_support || otg_caps->srp_support ||
+						otg_caps->adp_support))
+		ci->gadget.is_otg = 1;
+
+	INIT_LIST_HEAD(&ci->gadget.ep_list);
+
+	/* alloc resources */
+	ci->qh_pool = dma_pool_create("ci_hw_qh", dev->parent,
+				       sizeof(struct ci_hw_qh),
+				       64, CI_HDRC_PAGE_SIZE);
+	if (ci->qh_pool == NULL)
+		return -ENOMEM;
+
+	ci->td_pool = dma_pool_create("ci_hw_td", dev->parent,
+				       sizeof(struct ci_hw_td),
+				       64, CI_HDRC_PAGE_SIZE);
+	if (ci->td_pool == NULL) {
+		retval = -ENOMEM;
+		goto free_qh_pool;
+	}
+
+	retval = init_eps(ci);
+	if (retval)
+		goto free_pools;
+
+	ci->gadget.ep0 = &ci->ep0in->ep;
+
+	retval = usb_add_gadget_udc(dev, &ci->gadget);
+	if (retval)
+		goto destroy_eps;
+
+	return retval;
+
+destroy_eps:
+	destroy_eps(ci);
+free_pools:
+	dma_pool_destroy(ci->td_pool);
+free_qh_pool:
+	dma_pool_destroy(ci->qh_pool);
+	return retval;
+}
+
+/*
+ * ci_hdrc_gadget_destroy: parent remove must call this to remove UDC
+ *
+ * No interrupts active, the IRQ has been released
+ */
+void ci_hdrc_gadget_destroy(struct ci_hdrc *ci)
+{
+	if (!ci->roles[CI_ROLE_GADGET])
+		return;
+
+	usb_del_gadget_udc(&ci->gadget);
+
+	destroy_eps(ci);
+
+	dma_pool_destroy(ci->td_pool);
+	dma_pool_destroy(ci->qh_pool);
+}
+
+static int udc_id_switch_for_device(struct ci_hdrc *ci)
+{
+	if (ci->platdata->pins_device)
+		pinctrl_select_state(ci->platdata->pctl,
+				     ci->platdata->pins_device);
+
+	if (ci->is_otg)
+		/* Clear and enable BSV irq */
+		hw_write_otgsc(ci, OTGSC_BSVIS | OTGSC_BSVIE,
+					OTGSC_BSVIS | OTGSC_BSVIE);
+
+	return 0;
+}
+
+static void udc_id_switch_for_host(struct ci_hdrc *ci)
+{
+	/*
+	 * host doesn't care B_SESSION_VALID event
+	 * so clear and disbale BSV irq
+	 */
+	if (ci->is_otg)
+		hw_write_otgsc(ci, OTGSC_BSVIE | OTGSC_BSVIS, OTGSC_BSVIS);
+
+	ci->vbus_active = 0;
+
+	if (ci->platdata->pins_device && ci->platdata->pins_default)
+		pinctrl_select_state(ci->platdata->pctl,
+				     ci->platdata->pins_default);
+}
+
+/**
+ * ci_hdrc_gadget_init - initialize device related bits
+ * @ci: the controller
+ *
+ * This function initializes the gadget, if the device is "device capable".
+ */
+int ci_hdrc_gadget_init(struct ci_hdrc *ci)
+{
+	struct ci_role_driver *rdrv;
+	int ret;
+
+	if (!hw_read(ci, CAP_DCCPARAMS, DCCPARAMS_DC))
+		return -ENXIO;
+
+	rdrv = devm_kzalloc(ci->dev, sizeof(*rdrv), GFP_KERNEL);
+	if (!rdrv)
+		return -ENOMEM;
+
+	rdrv->start	= udc_id_switch_for_device;
+	rdrv->stop	= udc_id_switch_for_host;
+	rdrv->irq	= udc_irq;
+	rdrv->name	= "gadget";
+
+	ret = udc_start(ci);
+	if (!ret)
+		ci->roles[CI_ROLE_GADGET] = rdrv;
+
+	return ret;
+}