usb: gadget: dwc3: Add support for DBM (MSM specific) endpoints.

In MSM architecture, the DBM, Device Bus Manager, is a HW module within
the USB3.0 core wrapper, implementing BAM interface support for USB3.0 IP.
The DBM HW unit requires for its operation a special transfer to be
started, with special TRBs structure. These usb requests will operate in
BAM2BAM mode.

This change adds to the dwc3-msm.c driver a support for queuing
a special transfers to endpoints which serve the DBM.

A function driver can now call to msm_ep_config(*ep) with some
endpoint which will serve the DBM. After this, the function
driver can queue a request to this endpoint as usual ep->queue(*ep,*req).
The function driver may need to add a few more parameters in req->udc_priv
field according to the bit mask fields defined in msm_hsudb.h file.

Change-Id: Iad530dabc68414c61d44e9eaef4402f868b2b12f
Signed-off-by: Ido Shayevitz <idos@codeaurora.org>
diff --git a/drivers/usb/dwc3/dwc3-msm.c b/drivers/usb/dwc3/dwc3-msm.c
index d1299d4..4e6091e 100644
--- a/drivers/usb/dwc3/dwc3-msm.c
+++ b/drivers/usb/dwc3/dwc3-msm.c
@@ -20,20 +20,736 @@
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/types.h>
-#include <linux/usb/msm_hsusb.h>
 #include <linux/delay.h>
 #include <linux/of.h>
+#include <linux/list.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb/msm_hsusb.h>
+
+#include "core.h"
+#include "gadget.h"
+
+/**
+ *  USB DBM Hardware registers.
+ *
+ */
+#define DBM_EP_CFG(n)		(0x00 + 4 * (n))
+#define DBM_DATA_FIFO(n)	(0x10 + 4 * (n))
+#define DBM_DATA_FIFO_SIZE(n)	(0x20 + 4 * (n))
+#define DBM_DATA_FIFO_EN	(0x30)
+#define DBM_GEVNTADR		(0x34)
+#define DBM_GEVNTSIZ		(0x38)
+#define DBM_DBG_CNFG		(0x3C)
+#define DBM_HW_TRB0_EP(n)	(0x40 + 4 * (n))
+#define DBM_HW_TRB1_EP(n)	(0x50 + 4 * (n))
+#define DBM_HW_TRB2_EP(n)	(0x60 + 4 * (n))
+#define DBM_HW_TRB3_EP(n)	(0x70 + 4 * (n))
+#define DBM_PIPE_CFG		(0x80)
+#define DBM_SOFT_RESET		(0x84)
+
+/**
+ *  USB DBM  Hardware registers bitmask.
+ *
+ */
+/* DBM_EP_CFG */
+#define DBM_EN_EP		0x00000000
+#define DBM_USB3_EP_NUM		0x0000003E
+#define DBM_BAM_PIPE_NUM	0x000000C0
+#define DBM_PRODUCER		0x00000100
+#define DBM_DISABLE_WB		0x00000200
+#define DBM_INT_RAM_ACC		0x00000400
+
+/* DBM_DATA_FIFO_SIZE */
+#define DBM_DATA_FIFO_SIZE_MASK	0x0000ffff
+
+/* DBM_GEVNTSIZ */
+#define DBM_GEVNTSIZ_MASK	0x0000ffff
+
+/* DBM_DBG_CNFG */
+#define DBM_ENABLE_IOC_MASK	0x0000000f
+
+/* DBM_SOFT_RESET */
+#define DBM_SFT_RST_EP0		0x00000001
+#define DBM_SFT_RST_EP1		0x00000002
+#define DBM_SFT_RST_EP2		0x00000004
+#define DBM_SFT_RST_EP3		0x00000008
+#define DBM_SFT_RST_EPS		0x0000000F
+#define DBM_SFT_RST		0x80000000
 
 #define DBM_MAX_EPS		4
 
+struct dwc3_msm_req_complete {
+	struct list_head list_item;
+	struct usb_request *req;
+	void (*orig_complete)(struct usb_ep *ep,
+			      struct usb_request *req);
+};
+
 struct dwc3_msm {
 	struct platform_device *dwc3;
 	struct device *dev;
 	void __iomem *base;
 	u32 resource_size;
 	int dbm_num_eps;
+	u8 ep_num_mapping[DBM_MAX_EPS];
+	const struct usb_ep_ops *original_ep_ops[DWC3_ENDPOINTS_NUM];
+	struct list_head req_complete_list;
 };
 
+static struct dwc3_msm *context;
+
+/**
+ *
+ * Read register with debug info.
+ *
+ * @base - DWC3 base virtual address.
+ * @offset - register offset.
+ *
+ * @return u32
+ */
+static inline u32 dwc3_msm_read_reg(void *base, u32 offset)
+{
+	u32 val = ioread32(base + offset);
+	return val;
+}
+
+/**
+ * Read register masked field with debug info.
+ *
+ * @base - DWC3 base virtual address.
+ * @offset - register offset.
+ * @mask - register bitmask.
+ *
+ * @return u32
+ */
+static inline u32 dwc3_msm_read_reg_field(void *base,
+					  u32 offset,
+					  const u32 mask)
+{
+	u32 shift = find_first_bit((void *)&mask, 32);
+	u32 val = ioread32(base + offset);
+	val &= mask;		/* clear other bits */
+	val >>= shift;
+	return val;
+}
+
+/**
+ *
+ * Write register with debug info.
+ *
+ * @base - DWC3 base virtual address.
+ * @offset - register offset.
+ * @val - value to write.
+ *
+ */
+static inline void dwc3_msm_write_reg(void *base, u32 offset, u32 val)
+{
+	iowrite32(val, base + offset);
+}
+
+/**
+ * Write register masked field with debug info.
+ *
+ * @base - DWC3 base virtual address.
+ * @offset - register offset.
+ * @mask - register bitmask.
+ * @val - value to write.
+ *
+ */
+static inline void dwc3_msm_write_reg_field(void *base, u32 offset,
+					    const u32 mask, u32 val)
+{
+	u32 shift = find_first_bit((void *)&mask, 32);
+	u32 tmp = ioread32(base + offset);
+
+	tmp &= ~mask;		/* clear written bits */
+	val = tmp | (val << shift);
+	iowrite32(val, base + offset);
+}
+
+/**
+ * Return DBM EP number which is not already configured.
+ *
+ */
+static int dwc3_msm_find_avail_dbm_ep(void)
+{
+	int i;
+
+	for (i = 0; i < context->dbm_num_eps; i++)
+		if (!context->ep_num_mapping[i])
+			return i;
+
+	return -ENODEV; /* Not found */
+}
+
+/**
+ * Return DBM EP number according to usb endpoint number.
+ *
+ */
+static int dwc3_msm_find_matching_dbm_ep(u8 usb_ep)
+{
+	int i;
+
+	for (i = 0; i < context->dbm_num_eps; i++)
+		if (context->ep_num_mapping[i] == usb_ep)
+			return i;
+
+	return -ENODEV; /* Not found */
+}
+
+/**
+ * Return number of configured DBM endpoints.
+ *
+ */
+static int dwc3_msm_configured_dbm_ep_num(void)
+{
+	int i;
+	int count = 0;
+
+	for (i = 0; i < context->dbm_num_eps; i++)
+		if (context->ep_num_mapping[i])
+			count++;
+
+	return count;
+}
+
+/**
+ * Configure the DBM with the USB3 core event buffer.
+ * This function is called by the SNPS UDC upon initialization.
+ *
+ * @addr - address of the event buffer.
+ * @size - size of the event buffer.
+ *
+ */
+static int dwc3_msm_event_buffer_config(u32 addr, u16 size)
+{
+	dev_dbg(context->dev, "%s\n", __func__);
+
+	dwc3_msm_write_reg(context->base, DBM_GEVNTADR, addr);
+	dwc3_msm_write_reg_field(context->base, DBM_GEVNTSIZ,
+		DBM_GEVNTSIZ_MASK, size);
+
+	return 0;
+}
+
+/**
+ * Reset the DBM registers upon initialization.
+ *
+ */
+static int dwc3_msm_dbm_soft_reset(void)
+{
+	dev_dbg(context->dev, "%s\n", __func__);
+
+	dwc3_msm_write_reg_field(context->base, DBM_SOFT_RESET,
+		DBM_SFT_RST, 1);
+
+	return 0;
+}
+
+/**
+ * Soft reset specific DBM ep.
+ * This function is called by the function driver upon events
+ * such as transfer aborting, USB re-enumeration and USB
+ * disconnection.
+ *
+ * @dbm_ep - DBM ep number.
+ * @enter_reset - should we enter a reset state or get out of it.
+ *
+ */
+static int dwc3_msm_dbm_ep_soft_reset(u8 dbm_ep, bool enter_reset)
+{
+	dev_dbg(context->dev, "%s\n", __func__);
+
+	if (dbm_ep >= context->dbm_num_eps) {
+		dev_err(context->dev,
+				"%s: Invalid DBM ep index\n", __func__);
+		return -ENODEV;
+	}
+
+	if (enter_reset) {
+		dwc3_msm_write_reg_field(context->base, DBM_SOFT_RESET,
+			DBM_SFT_RST_EPS, 1 << dbm_ep);
+	} else {
+		dwc3_msm_write_reg_field(context->base, DBM_SOFT_RESET,
+			DBM_SFT_RST_EPS, 0);
+	}
+
+	return 0;
+}
+
+/**
+ * Configure a USB DBM ep to work in BAM mode.
+ *
+ *
+ * @usb_ep - USB physical EP number.
+ * @producer - producer/consumer.
+ * @disable_wb - disable write back to system memory.
+ * @internal_mem - use internal USB memory for data fifo.
+ * @ioc - enable interrupt on completion.
+ *
+ * @return int - DBM ep number.
+ */
+static int dwc3_msm_dbm_ep_config(u8 usb_ep, u8 bam_pipe,
+				  bool producer, bool disable_wb,
+				  bool internal_mem, bool ioc)
+{
+	u8 dbm_ep;
+	u8 ioc_mask;
+
+	dev_dbg(context->dev, "%s\n", __func__);
+
+	dbm_ep = dwc3_msm_find_avail_dbm_ep();
+	if (dbm_ep < 0) {
+		dev_err(context->dev, "%s: No more DBM eps\n", __func__);
+		return -ENODEV;
+	}
+
+	context->ep_num_mapping[dbm_ep] = usb_ep;
+
+	/* First, reset the dbm endpoint */
+	dwc3_msm_dbm_ep_soft_reset(dbm_ep, false);
+
+	ioc_mask = dwc3_msm_read_reg_field(context->base, DBM_DBG_CNFG,
+		DBM_ENABLE_IOC_MASK);
+	ioc_mask &= ~(ioc << dbm_ep); /* Clear ioc bit for dbm_ep */
+	/* Set ioc bit for dbm_ep if needed */
+	dwc3_msm_write_reg_field(context->base, DBM_DBG_CNFG,
+		DBM_ENABLE_IOC_MASK, ioc_mask | (ioc << dbm_ep));
+
+	dwc3_msm_write_reg(context->base, DBM_EP_CFG(dbm_ep),
+		producer | disable_wb | internal_mem);
+	dwc3_msm_write_reg_field(context->base, DBM_EP_CFG(dbm_ep),
+		DBM_USB3_EP_NUM, usb_ep);
+	dwc3_msm_write_reg_field(context->base, DBM_EP_CFG(dbm_ep),
+		DBM_BAM_PIPE_NUM, bam_pipe);
+	dwc3_msm_write_reg_field(context->base, DBM_EP_CFG(dbm_ep),
+		DBM_EN_EP, 1);
+
+	return dbm_ep;
+}
+
+/**
+ * Configure a USB DBM ep to work in normal mode.
+ *
+ * @usb_ep - USB ep number.
+ *
+ */
+static int dwc3_msm_dbm_ep_unconfig(u8 usb_ep)
+{
+	u8 dbm_ep;
+
+	dev_dbg(context->dev, "%s\n", __func__);
+
+	dbm_ep = dwc3_msm_find_matching_dbm_ep(usb_ep);
+
+	if (dbm_ep < 0) {
+		dev_err(context->dev,
+				"%s: Invalid usb ep index\n", __func__);
+		return -ENODEV;
+	}
+
+	context->ep_num_mapping[dbm_ep] = 0;
+
+	dwc3_msm_write_reg(context->base, DBM_EP_CFG(dbm_ep), 0);
+
+	/* Reset the dbm endpoint */
+	dwc3_msm_dbm_ep_soft_reset(dbm_ep, true);
+
+	return 0;
+}
+
+/**
+ * Configure the DBM with the BAM's data fifo.
+ * This function is called by the USB BAM Driver
+ * upon initialization.
+ *
+ * @ep - pointer to usb endpoint.
+ * @addr - address of data fifo.
+ * @size - size of data fifo.
+ *
+ */
+int msm_data_fifo_config(struct usb_ep *ep, u32 addr, u32 size)
+{
+	u8 dbm_ep;
+	struct dwc3_ep *dep = to_dwc3_ep(ep);
+
+	dev_dbg(context->dev, "%s\n", __func__);
+
+	dbm_ep = dwc3_msm_find_matching_dbm_ep(dep->number);
+
+	if (dbm_ep >= context->dbm_num_eps) {
+		dev_err(context->dev,
+				"%s: Invalid DBM ep index\n", __func__);
+		return -ENODEV;
+	}
+
+	dwc3_msm_write_reg(context->base, DBM_DATA_FIFO(dbm_ep), addr);
+	dwc3_msm_write_reg_field(context->base, DBM_DATA_FIFO_SIZE(dbm_ep),
+		DBM_DATA_FIFO_SIZE_MASK, size);
+
+	return 0;
+}
+
+/**
+* Cleanups for msm endpoint on request complete.
+*
+* Also call original request complete.
+*
+* @usb_ep - pointer to usb_ep instance.
+* @request - pointer to usb_request instance.
+*
+* @return int - 0 on success, negetive on error.
+*/
+static void dwc3_msm_req_complete_func(struct usb_ep *ep,
+				       struct usb_request *request)
+{
+	struct dwc3_request *req = to_dwc3_request(request);
+	struct dwc3_ep *dep = to_dwc3_ep(ep);
+	struct dwc3_msm_req_complete *req_complete = NULL;
+
+	/* Find original request complete function and remove it from list */
+	list_for_each_entry(req_complete,
+				&context->req_complete_list,
+				list_item) {
+		if (req_complete->req == request)
+			break;
+	}
+	if (!req_complete || req_complete->req != request) {
+		dev_err(dep->dwc->dev, "%s: could not find the request\n",
+					__func__);
+		return;
+	}
+	list_del(&req_complete->list_item);
+
+	/*
+	 * Release another one TRB to the pool since DBM queue took 2 TRBs
+	 * (normal and link), and the dwc3/gadget.c :: dwc3_gadget_giveback
+	 * released only one.
+	 */
+	if (req->queued)
+		dep->busy_slot++;
+
+	/* Unconfigure dbm ep */
+	dwc3_msm_dbm_ep_unconfig(dep->number);
+
+	/*
+	 * If this is the last endpoint we unconfigured, than reset also
+	 * the event buffers.
+	 */
+	if (0 == dwc3_msm_configured_dbm_ep_num())
+		dwc3_msm_event_buffer_config(0, 0);
+
+	/*
+	 * Call original complete function, notice that dwc->lock is already
+	 * taken by the caller of this function (dwc3_gadget_giveback()).
+	 */
+	request->complete = req_complete->orig_complete;
+	request->complete(ep, request);
+
+	kfree(req_complete);
+}
+
+/**
+* Helper function.
+* See the header of the dwc3_msm_ep_queue function.
+*
+* @dwc3_ep - pointer to dwc3_ep instance.
+* @req - pointer to dwc3_request instance.
+*
+* @return int - 0 on success, negetive on error.
+*/
+static int __dwc3_msm_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
+{
+	struct dwc3_trb_hw *trb_hw;
+	struct dwc3_trb_hw *trb_link_hw;
+	struct dwc3_trb trb;
+	struct dwc3_gadget_ep_cmd_params params;
+	u32 cmd;
+	int ret = 0;
+
+	if ((req->request.udc_priv & MSM_IS_FINITE_TRANSFER) &&
+	    (req->request.length > 0)) {
+		/* Map the request to a DMA. */
+		dwc3_map_buffer_to_dma(req);
+	}
+
+	/* We push the request to the dep->req_queued list to indicate that
+	 * this request is issued with start transfer. The request will be out
+	 * from this list in 2 cases. The first is that the transfer will be
+	 * completed (not if the transfer is endless using a circular TRBs with
+	 * with link TRB). The second case is an option to do stop stransfer,
+	 * this can be initiated by the function driver when calling dequeue.
+	 */
+	req->queued = true;
+	list_add_tail(&req->list, &dep->req_queued);
+
+	/* First, prepare a normal TRB, point to the fake buffer */
+	trb_hw = &dep->trb_pool[dep->free_slot & DWC3_TRB_MASK];
+	dep->free_slot++;
+	memset(&trb, 0, sizeof(trb));
+
+	req->trb = trb_hw;
+
+	trb.bplh = req->request.dma;
+	trb.lst = 0;
+	trb.trbctl = DWC3_TRBCTL_NORMAL;
+	trb.length = req->request.length;
+	trb.hwo = true;
+
+	dwc3_trb_to_hw(&trb, trb_hw);
+	req->trb_dma = dep->trb_pool_dma;
+
+	/* Second, prepare a Link TRB that points to the first TRB*/
+	trb_link_hw = &dep->trb_pool[dep->free_slot & DWC3_TRB_MASK];
+	dep->free_slot++;
+	memset(&trb, 0, sizeof(trb));
+
+	trb.bplh = dep->trb_pool_dma;
+	trb.trbctl = DWC3_TRBCTL_LINK_TRB;
+	trb.hwo = true;
+
+	dwc3_trb_to_hw(&trb, trb_link_hw);
+
+	/*
+	 * Now start the transfer
+	 */
+	memset(&params, 0, sizeof(params));
+	params.param0 = upper_32_bits(req->trb_dma);
+	params.param1 = lower_32_bits(req->trb_dma);
+	cmd = DWC3_DEPCMD_STARTTRANSFER;
+	ret = dwc3_send_gadget_ep_cmd(dep->dwc, dep->number, cmd, &params);
+	if (ret < 0) {
+		dev_dbg(dep->dwc->dev,
+			"%s: failed to send STARTTRANSFER command\n",
+			__func__);
+
+		dwc3_unmap_buffer_from_dma(req);
+		list_del(&req->list);
+		return ret;
+	}
+
+	return ret;
+}
+
+/**
+* Queue a usb request to the DBM endpoint.
+* This function should be called after the endpoint
+* was enabled by the ep_enable.
+*
+* This function prepares special structure of TRBs which
+* is familier with the DBM HW, so it will possible to use
+* this endpoint in DBM mode.
+*
+* The TRBs prepared by this function, is one normal TRB
+* which point to a fake buffer, followed by a link TRB
+* that points to the first TRB.
+*
+* The API of this function follow the regular API of
+* usb_ep_queue (see usb_ep_ops in include/linuk/usb/gadget.h).
+*
+* @usb_ep - pointer to usb_ep instance.
+* @request - pointer to usb_request instance.
+* @gfp_flags - possible flags.
+*
+* @return int - 0 on success, negetive on error.
+*/
+static int dwc3_msm_ep_queue(struct usb_ep *ep,
+			     struct usb_request *request, gfp_t gfp_flags)
+{
+	struct dwc3_request *req = to_dwc3_request(request);
+	struct dwc3_ep *dep = to_dwc3_ep(ep);
+	struct dwc3 *dwc = dep->dwc;
+	struct dwc3_msm_req_complete *req_complete;
+	unsigned long flags;
+	int ret = 0;
+	u8 bam_pipe;
+	bool producer;
+	bool disable_wb;
+	bool internal_mem;
+	bool ioc;
+
+	if (!(request->udc_priv & MSM_SPS_MODE)) {
+		/* Not SPS mode, call original queue */
+		dev_vdbg(dwc->dev, "%s: not sps mode, use regular queue\n",
+					__func__);
+
+		return (context->original_ep_ops[dep->number])->queue(ep,
+								request,
+								gfp_flags);
+	}
+
+	if (!dep->endpoint.desc) {
+		dev_err(dwc->dev,
+			"%s: trying to queue request %p to disabled ep %s\n",
+			__func__, request, ep->name);
+		return -EPERM;
+	}
+
+	if (dep->number == 0 || dep->number == 1) {
+		dev_err(dwc->dev,
+			"%s: trying to queue dbm request %p to control ep %s\n",
+			__func__, request, ep->name);
+		return -EPERM;
+	}
+
+	if (dep->free_slot > 0 || dep->busy_slot > 0 ||
+		!list_empty(&dep->request_list) ||
+		!list_empty(&dep->req_queued)) {
+
+		dev_err(dwc->dev,
+			"%s: trying to queue dbm request %p tp ep %s\n",
+			__func__, request, ep->name);
+		return -EPERM;
+	}
+
+	/*
+	 * Override req->complete function, but before doing that,
+	 * store it's original pointer in the req_complete_list.
+	 */
+	req_complete = kzalloc(sizeof(*req_complete), GFP_KERNEL);
+	if (!req_complete) {
+		dev_err(dep->dwc->dev, "%s: not enough memory\n", __func__);
+		return -ENOMEM;
+	}
+	req_complete->req = request;
+	req_complete->orig_complete = request->complete;
+	list_add_tail(&req_complete->list_item, &context->req_complete_list);
+	request->complete = dwc3_msm_req_complete_func;
+
+	/*
+	 * Configure dbm event buffers if this is the first
+	 * dbm endpoint we about to configure.
+	 */
+	if (0 == dwc3_msm_configured_dbm_ep_num())
+		dwc3_msm_event_buffer_config(dwc->ev_buffs[0]->dma,
+					     dwc->ev_buffs[0]->length);
+
+	/*
+	 * Configure the DBM endpoint
+	 */
+	bam_pipe = (request->udc_priv & MSM_PIPE_ID_MASK);
+	producer = ((request->udc_priv & MSM_PRODUCER) ? true : false);
+	disable_wb = ((request->udc_priv & MSM_DISABLE_WB) ? true : false);
+	internal_mem = ((request->udc_priv & MSM_INTERNAL_MEM) ? true : false);
+	ioc = ((request->udc_priv & MSM_ETD_IOC) ? true : false);
+
+	ret = dwc3_msm_dbm_ep_config(dep->number,
+					bam_pipe, producer,
+					disable_wb, internal_mem, ioc);
+	if (ret < 0) {
+		dev_err(context->dev,
+			"error %d after calling dwc3_msm_dbm_ep_config\n",
+			ret);
+		return ret;
+	}
+
+	dev_vdbg(dwc->dev, "%s: queing request %p to ep %s length %d\n",
+			__func__, request, ep->name, request->length);
+
+	/*
+	 * We must obtain the lock of the dwc3 core driver,
+	 * including disabling interrupts, so we will be sure
+	 * that we are the only ones that configure the HW device
+	 * core and ensure that we queuing the request will finish
+	 * as soon as possible so we will release back the lock.
+	 */
+	spin_lock_irqsave(&dwc->lock, flags);
+	ret = __dwc3_msm_ep_queue(dep, req);
+	spin_unlock_irqrestore(&dwc->lock, flags);
+	if (ret < 0) {
+		dev_err(context->dev,
+			"error %d after calling __dwc3_msm_ep_queue\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * Configure MSM endpoint.
+ * This function do specific configurations
+ * to an endpoint which need specific implementaion
+ * in the MSM architecture.
+ *
+ * This function should be called by usb function/class
+ * layer which need a support from the specific MSM HW
+ * which wrap the USB3 core. (like DBM specific endpoints)
+ *
+ * @ep - a pointer to some usb_ep instance
+ *
+ * @return int - 0 on success, negetive on error.
+ */
+int msm_ep_config(struct usb_ep *ep)
+{
+	struct dwc3_ep *dep = to_dwc3_ep(ep);
+	struct usb_ep_ops *new_ep_ops;
+
+	/* Save original ep ops for future restore*/
+	if (context->original_ep_ops[dep->number]) {
+		dev_err(context->dev,
+			"ep [%s,%d] already configured as msm endpoint\n",
+			ep->name, dep->number);
+		return -EPERM;
+	}
+	context->original_ep_ops[dep->number] = ep->ops;
+
+	/* Set new usb ops as we like */
+	new_ep_ops = kzalloc(sizeof(struct usb_ep_ops), GFP_KERNEL);
+	if (!new_ep_ops) {
+		dev_err(context->dev,
+			"%s: unable to allocate mem for new usb ep ops\n",
+			__func__);
+		return -ENOMEM;
+	}
+	(*new_ep_ops) = (*ep->ops);
+	new_ep_ops->queue = dwc3_msm_ep_queue;
+	ep->ops = new_ep_ops;
+
+	/*
+	 * Do HERE more usb endpoint configurations
+	 * which are specific to MSM.
+	 */
+
+	return 0;
+}
+EXPORT_SYMBOL(msm_ep_config);
+
+/**
+ * Un-configure MSM endpoint.
+ * Tear down configurations done in the
+ * dwc3_msm_ep_config function.
+ *
+ * @ep - a pointer to some usb_ep instance
+ *
+ * @return int - 0 on success, negetive on error.
+ */
+int msm_ep_unconfig(struct usb_ep *ep)
+{
+	struct dwc3_ep *dep = to_dwc3_ep(ep);
+	struct usb_ep_ops *old_ep_ops;
+
+	/* Restore original ep ops */
+	if (!context->original_ep_ops[dep->number]) {
+		dev_err(context->dev,
+			"ep [%s,%d] was not configured as msm endpoint\n",
+			ep->name, dep->number);
+		return -EINVAL;
+	}
+	old_ep_ops = (struct usb_ep_ops	*)ep->ops;
+	ep->ops = context->original_ep_ops[dep->number];
+	context->original_ep_ops[dep->number] = NULL;
+	kfree(old_ep_ops);
+
+	/*
+	 * Do HERE more usb endpoint un-configurations
+	 * which are specific to MSM.
+	 */
+
+	return 0;
+}
+EXPORT_SYMBOL(msm_ep_unconfig);
+
 static int __devinit dwc3_msm_probe(struct platform_device *pdev)
 {
 	struct device_node *node = pdev->dev.of_node;
@@ -49,6 +765,9 @@
 	}
 
 	platform_set_drvdata(pdev, msm);
+	context = msm;
+
+	INIT_LIST_HEAD(&msm->req_complete_list);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
@@ -107,6 +826,9 @@
 		goto err1;
 	}
 
+	/* Reset the DBM */
+	dwc3_msm_dbm_soft_reset();
+
 	return 0;
 
 err1: