]> git.karo-electronics.de Git - karo-tx-linux.git/commitdiff
usb: gadget: Add xilinx usb2 device support
authorSubbaraya Sundeep Bhatta <subbaraya.sundeep.bhatta@xilinx.com>
Wed, 10 Sep 2014 13:54:04 +0000 (19:24 +0530)
committerFelipe Balbi <balbi@ti.com>
Fri, 12 Sep 2014 14:12:49 +0000 (09:12 -0500)
Xilinx USB2 device is a soft IP which supports both full
and high speed USB 2.0 data transfers. This patch adds
xilinx usb2 device driver support.

Signed-off-by: Subbaraya Sundeep Bhatta <sbhatta@xilinx.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
drivers/usb/gadget/udc/Kconfig
drivers/usb/gadget/udc/Makefile
drivers/usb/gadget/udc/udc-xilinx.c [new file with mode: 0644]

index 0c172809b53b13f84a72856a8b99d9f4cef473dd..3ea287b0e448a1e50b01ee2be78ba18bdf5d7e23 100644 (file)
@@ -354,6 +354,21 @@ config USB_EG20T
          ML7213/ML7831 is completely compatible for Intel EG20T PCH.
 
          This driver can be used with Intel's Quark X1000 SOC platform
+
+config USB_GADGET_XILINX
+       tristate "Xilinx USB Driver"
+       depends on OF || COMPILE_TEST
+       help
+         USB peripheral controller driver for Xilinx USB2 device.
+         Xilinx USB2 device is a soft IP which supports both full
+         and high speed USB 2.0 data transfers. It has seven configurable
+         endpoints(bulk or interrupt or isochronous), as well as
+         endpoint zero(for control transfers).
+
+         Say "y" to link the driver statically, or "m" to build a
+         dynamically linked module called "udc-xilinx" and force all
+         gadget drivers to also be dynamically linked.
+
 #
 # LAST -- dummy/emulated controller
 #
index 4096122bb283bd73e4aba8a08c97130226a52881..a7f4491593f122a8d3f5813304d8929611e3d456 100644 (file)
@@ -29,3 +29,4 @@ obj-$(CONFIG_USB_FUSB300)     += fusb300_udc.o
 obj-$(CONFIG_USB_FOTG210_UDC)  += fotg210-udc.o
 obj-$(CONFIG_USB_MV_U3D)       += mv_u3d_core.o
 obj-$(CONFIG_USB_GR_UDC)       += gr_udc.o
+obj-$(CONFIG_USB_GADGET_XILINX)        += udc-xilinx.o
diff --git a/drivers/usb/gadget/udc/udc-xilinx.c b/drivers/usb/gadget/udc/udc-xilinx.c
new file mode 100644 (file)
index 0000000..ed27e16
--- /dev/null
@@ -0,0 +1,2180 @@
+/*
+ * Xilinx USB peripheral controller driver
+ *
+ * Copyright (C) 2004 by Thomas Rathbone
+ * Copyright (C) 2005 by HP Labs
+ * Copyright (C) 2005 by David Brownell
+ * Copyright (C) 2010 - 2014 Xilinx, Inc.
+ *
+ * Some parts of this driver code is based on the driver for at91-series
+ * USB peripheral controller (at91_udc.c).
+ *
+ * This program is free software; you can redistribute it
+ * and/or modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation;
+ * either version 2 of the License, or (at your option) any
+ * later version.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_irq.h>
+#include <linux/prefetch.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+
+/* Register offsets for the USB device.*/
+#define XUSB_EP0_CONFIG_OFFSET         0x0000  /* EP0 Config Reg Offset */
+#define XUSB_SETUP_PKT_ADDR_OFFSET     0x0080  /* Setup Packet Address */
+#define XUSB_ADDRESS_OFFSET            0x0100  /* Address Register */
+#define XUSB_CONTROL_OFFSET            0x0104  /* Control Register */
+#define XUSB_STATUS_OFFSET             0x0108  /* Status Register */
+#define XUSB_FRAMENUM_OFFSET           0x010C  /* Frame Number Register */
+#define XUSB_IER_OFFSET                        0x0110  /* Interrupt Enable Register */
+#define XUSB_BUFFREADY_OFFSET          0x0114  /* Buffer Ready Register */
+#define XUSB_TESTMODE_OFFSET           0x0118  /* Test Mode Register */
+#define XUSB_DMA_RESET_OFFSET          0x0200  /* DMA Soft Reset Register */
+#define XUSB_DMA_CONTROL_OFFSET                0x0204  /* DMA Control Register */
+#define XUSB_DMA_DSAR_ADDR_OFFSET      0x0208  /* DMA source Address Reg */
+#define XUSB_DMA_DDAR_ADDR_OFFSET      0x020C  /* DMA destination Addr Reg */
+#define XUSB_DMA_LENGTH_OFFSET         0x0210  /* DMA Length Register */
+#define XUSB_DMA_STATUS_OFFSET         0x0214  /* DMA Status Register */
+
+/* Endpoint Configuration Space offsets */
+#define XUSB_EP_CFGSTATUS_OFFSET       0x00    /* Endpoint Config Status  */
+#define XUSB_EP_BUF0COUNT_OFFSET       0x08    /* Buffer 0 Count */
+#define XUSB_EP_BUF1COUNT_OFFSET       0x0C    /* Buffer 1 Count */
+
+#define XUSB_CONTROL_USB_READY_MASK    0x80000000 /* USB ready Mask */
+#define XUSB_CONTROL_USB_RMTWAKE_MASK  0x40000000 /* Remote wake up mask */
+
+/* Interrupt register related masks.*/
+#define XUSB_STATUS_GLOBAL_INTR_MASK   0x80000000 /* Global Intr Enable */
+#define XUSB_STATUS_DMADONE_MASK       0x04000000 /* DMA done Mask */
+#define XUSB_STATUS_DMAERR_MASK                0x02000000 /* DMA Error Mask */
+#define XUSB_STATUS_DMABUSY_MASK       0x80000000 /* DMA Error Mask */
+#define XUSB_STATUS_RESUME_MASK                0x01000000 /* USB Resume Mask */
+#define XUSB_STATUS_RESET_MASK         0x00800000 /* USB Reset Mask */
+#define XUSB_STATUS_SUSPEND_MASK       0x00400000 /* USB Suspend Mask */
+#define XUSB_STATUS_DISCONNECT_MASK    0x00200000 /* USB Disconnect Mask */
+#define XUSB_STATUS_FIFO_BUFF_RDY_MASK 0x00100000 /* FIFO Buff Ready Mask */
+#define XUSB_STATUS_FIFO_BUFF_FREE_MASK        0x00080000 /* FIFO Buff Free Mask */
+#define XUSB_STATUS_SETUP_PACKET_MASK  0x00040000 /* Setup packet received */
+#define XUSB_STATUS_EP1_BUFF2_COMP_MASK        0x00000200 /* EP 1 Buff 2 Processed */
+#define XUSB_STATUS_EP1_BUFF1_COMP_MASK        0x00000002 /* EP 1 Buff 1 Processed */
+#define XUSB_STATUS_EP0_BUFF2_COMP_MASK        0x00000100 /* EP 0 Buff 2 Processed */
+#define XUSB_STATUS_EP0_BUFF1_COMP_MASK        0x00000001 /* EP 0 Buff 1 Processed */
+#define XUSB_STATUS_HIGH_SPEED_MASK    0x00010000 /* USB Speed Mask */
+/* Suspend,Reset,Suspend and Disconnect Mask */
+#define XUSB_STATUS_INTR_EVENT_MASK    0x01E00000
+/* Buffers  completion Mask */
+#define XUSB_STATUS_INTR_BUFF_COMP_ALL_MASK    0x0000FEFF
+/* Mask for buffer 0 and buffer 1 completion for all Endpoints */
+#define XUSB_STATUS_INTR_BUFF_COMP_SHIFT_MASK  0x00000101
+#define XUSB_STATUS_EP_BUFF2_SHIFT     8          /* EP buffer offset */
+
+/* Endpoint Configuration Status Register */
+#define XUSB_EP_CFG_VALID_MASK         0x80000000 /* Endpoint Valid bit */
+#define XUSB_EP_CFG_STALL_MASK         0x40000000 /* Endpoint Stall bit */
+#define XUSB_EP_CFG_DATA_TOGGLE_MASK   0x08000000 /* Endpoint Data toggle */
+
+/* USB device specific global configuration constants.*/
+#define XUSB_MAX_ENDPOINTS             8       /* Maximum End Points */
+#define XUSB_EP_NUMBER_ZERO            0       /* End point Zero */
+/* DPRAM is the source address for DMA transfer */
+#define XUSB_DMA_READ_FROM_DPRAM       0x80000000
+#define XUSB_DMA_DMASR_BUSY            0x80000000 /* DMA busy */
+#define XUSB_DMA_DMASR_ERROR           0x40000000 /* DMA Error */
+/*
+ * When this bit is set, the DMA buffer ready bit is set by hardware upon
+ * DMA transfer completion.
+ */
+#define XUSB_DMA_BRR_CTRL              0x40000000 /* DMA bufready ctrl bit */
+/* Phase States */
+#define SETUP_PHASE                    0x0000  /* Setup Phase */
+#define DATA_PHASE                     0x0001  /* Data Phase */
+#define STATUS_PHASE                   0x0002  /* Status Phase */
+
+#define EP0_MAX_PACKET         64 /* Endpoint 0 maximum packet length */
+#define STATUSBUFF_SIZE                2  /* Buffer size for GET_STATUS command */
+#define EPNAME_SIZE            4  /* Buffer size for endpoint name */
+
+/* container_of helper macros */
+#define to_udc(g)       container_of((g), struct xusb_udc, gadget)
+#define to_xusb_ep(ep)  container_of((ep), struct xusb_ep, ep_usb)
+#define to_xusb_req(req) container_of((req), struct xusb_req, usb_req)
+
+/**
+ * struct xusb_req - Xilinx USB device request structure
+ * @usb_req: Linux usb request structure
+ * @queue: usb device request queue
+ * @ep: pointer to xusb_endpoint structure
+ */
+struct xusb_req {
+       struct usb_request usb_req;
+       struct list_head queue;
+       struct xusb_ep *ep;
+};
+
+/**
+ * struct xusb_ep - USB end point structure.
+ * @ep_usb: usb endpoint instance
+ * @queue: endpoint message queue
+ * @udc: xilinx usb peripheral driver instance pointer
+ * @desc: pointer to the usb endpoint descriptor
+ * @rambase: the endpoint buffer address
+ * @offset: the endpoint register offset value
+ * @name: name of the endpoint
+ * @epnumber: endpoint number
+ * @maxpacket: maximum packet size the endpoint can store
+ * @buffer0count: the size of the packet recieved in the first buffer
+ * @buffer1count: the size of the packet received in the second buffer
+ * @curbufnum: current buffer of endpoint that will be processed next
+ * @buffer0ready: the busy state of first buffer
+ * @buffer1ready: the busy state of second buffer
+ * @is_in: endpoint direction (IN or OUT)
+ * @is_iso: endpoint type(isochronous or non isochronous)
+ */
+struct xusb_ep {
+       struct usb_ep ep_usb;
+       struct list_head queue;
+       struct xusb_udc *udc;
+       const struct usb_endpoint_descriptor *desc;
+       u32  rambase;
+       u32  offset;
+       char name[4];
+       u16  epnumber;
+       u16  maxpacket;
+       u16  buffer0count;
+       u16  buffer1count;
+       u8   curbufnum;
+       bool buffer0ready;
+       bool buffer1ready;
+       bool is_in;
+       bool is_iso;
+};
+
+/**
+ * struct xusb_udc -  USB peripheral driver structure
+ * @gadget: USB gadget driver instance
+ * @ep: an array of endpoint structures
+ * @driver: pointer to the usb gadget driver instance
+ * @setup: usb_ctrlrequest structure for control requests
+ * @req: pointer to dummy request for get status command
+ * @dev: pointer to device structure in gadget
+ * @usb_state: device in suspended state or not
+ * @remote_wkp: remote wakeup enabled by host
+ * @setupseqtx: tx status
+ * @setupseqrx: rx status
+ * @addr: the usb device base address
+ * @lock: instance of spinlock
+ * @dma_enabled: flag indicating whether the dma is included in the system
+ * @read_fn: function pointer to read device registers
+ * @write_fn: function pointer to write to device registers
+ */
+struct xusb_udc {
+       struct usb_gadget gadget;
+       struct xusb_ep ep[8];
+       struct usb_gadget_driver *driver;
+       struct usb_ctrlrequest setup;
+       struct xusb_req *req;
+       struct device *dev;
+       u32 usb_state;
+       u32 remote_wkp;
+       u32 setupseqtx;
+       u32 setupseqrx;
+       void __iomem *addr;
+       spinlock_t lock;
+       bool dma_enabled;
+
+       unsigned int (*read_fn)(void __iomem *);
+       void (*write_fn)(void __iomem *, u32, u32);
+};
+
+/* Endpoint buffer start addresses in the core */
+static u32 rambase[8] = { 0x22, 0x1000, 0x1100, 0x1200, 0x1300, 0x1400, 0x1500,
+                         0x1600 };
+
+static const char driver_name[] = "xilinx-udc";
+static const char ep0name[] = "ep0";
+
+/* Control endpoint configuration.*/
+static const struct usb_endpoint_descriptor config_bulk_out_desc = {
+       .bLength                = USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType        = USB_DT_ENDPOINT,
+       .bEndpointAddress       = USB_DIR_OUT,
+       .bmAttributes           = USB_ENDPOINT_XFER_BULK,
+       .wMaxPacketSize         = cpu_to_le16(EP0_MAX_PACKET),
+};
+
+/**
+ * xudc_write32 - little endian write to device registers
+ * @addr: base addr of device registers
+ * @offset: register offset
+ * @val: data to be written
+ */
+static void xudc_write32(void __iomem *addr, u32 offset, u32 val)
+{
+       iowrite32(val, addr + offset);
+}
+
+/**
+ * xudc_read32 - little endian read from device registers
+ * @addr: addr of device register
+ * Return: value at addr
+ */
+static unsigned int xudc_read32(void __iomem *addr)
+{
+       return ioread32(addr);
+}
+
+/**
+ * xudc_write32_be - big endian write to device registers
+ * @addr: base addr of device registers
+ * @offset: register offset
+ * @val: data to be written
+ */
+static void xudc_write32_be(void __iomem *addr, u32 offset, u32 val)
+{
+       iowrite32be(val, addr + offset);
+}
+
+/**
+ * xudc_read32_be - big endian read from device registers
+ * @addr: addr of device register
+ * Return: value at addr
+ */
+static unsigned int xudc_read32_be(void __iomem *addr)
+{
+       return ioread32be(addr);
+}
+
+/**
+ * xudc_wrstatus - Sets up the usb device status stages.
+ * @udc: pointer to the usb device controller structure.
+ */
+static void xudc_wrstatus(struct xusb_udc *udc)
+{
+       struct xusb_ep *ep0 = &udc->ep[XUSB_EP_NUMBER_ZERO];
+       u32 epcfgreg;
+
+       epcfgreg = udc->read_fn(udc->addr + ep0->offset)|
+                               XUSB_EP_CFG_DATA_TOGGLE_MASK;
+       udc->write_fn(udc->addr, ep0->offset, epcfgreg);
+       udc->write_fn(udc->addr, ep0->offset + XUSB_EP_BUF0COUNT_OFFSET, 0);
+       udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET, 1);
+}
+
+/**
+ * xudc_epconfig - Configures the given endpoint.
+ * @ep: pointer to the usb device endpoint structure.
+ * @udc: pointer to the usb peripheral controller structure.
+ *
+ * This function configures a specific endpoint with the given configuration
+ * data.
+ */
+static void xudc_epconfig(struct xusb_ep *ep, struct xusb_udc *udc)
+{
+       u32 epcfgreg;
+
+       /*
+        * Configure the end point direction, type, Max Packet Size and the
+        * EP buffer location.
+        */
+       epcfgreg = ((ep->is_in << 29) | (ep->is_iso << 28) |
+                  (ep->ep_usb.maxpacket << 15) | (ep->rambase));
+       udc->write_fn(udc->addr, ep->offset, epcfgreg);
+
+       /* Set the Buffer count and the Buffer ready bits.*/
+       udc->write_fn(udc->addr, ep->offset + XUSB_EP_BUF0COUNT_OFFSET,
+                     ep->buffer0count);
+       udc->write_fn(udc->addr, ep->offset + XUSB_EP_BUF1COUNT_OFFSET,
+                     ep->buffer1count);
+       if (ep->buffer0ready)
+               udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET,
+                             1 << ep->epnumber);
+       if (ep->buffer1ready)
+               udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET,
+                             1 << (ep->epnumber + XUSB_STATUS_EP_BUFF2_SHIFT));
+}
+
+/**
+ * xudc_start_dma - Starts DMA transfer.
+ * @ep: pointer to the usb device endpoint structure.
+ * @src: DMA source address.
+ * @dst: DMA destination address.
+ * @length: number of bytes to transfer.
+ *
+ * Return: 0 on success, error code on failure
+ *
+ * This function starts DMA transfer by writing to DMA source,
+ * destination and lenth registers.
+ */
+static int xudc_start_dma(struct xusb_ep *ep, dma_addr_t src,
+                         dma_addr_t dst, u32 length)
+{
+       struct xusb_udc *udc = ep->udc;
+       int rc = 0;
+       u32 timeout = 500;
+       u32 reg;
+
+       /*
+        * Set the addresses in the DMA source and
+        * destination registers and then set the length
+        * into the DMA length register.
+        */
+       udc->write_fn(udc->addr, XUSB_DMA_DSAR_ADDR_OFFSET, src);
+       udc->write_fn(udc->addr, XUSB_DMA_DDAR_ADDR_OFFSET, dst);
+       udc->write_fn(udc->addr, XUSB_DMA_LENGTH_OFFSET, length);
+
+       /*
+        * Wait till DMA transaction is complete and
+        * check whether the DMA transaction was
+        * successful.
+        */
+       do {
+               reg = udc->read_fn(udc->addr + XUSB_DMA_STATUS_OFFSET);
+               if (!(reg &  XUSB_DMA_DMASR_BUSY))
+                       break;
+
+               /*
+                * We can't sleep here, because it's also called from
+                * interrupt context.
+                */
+               timeout--;
+               if (!timeout) {
+                       dev_err(udc->dev, "DMA timeout\n");
+                       return -ETIMEDOUT;
+               }
+               udelay(1);
+       } while (1);
+
+       if ((udc->read_fn(udc->addr + XUSB_DMA_STATUS_OFFSET) &
+                         XUSB_DMA_DMASR_ERROR) == XUSB_DMA_DMASR_ERROR){
+               dev_err(udc->dev, "DMA Error\n");
+               rc = -EINVAL;
+       }
+
+       return rc;
+}
+
+/**
+ * xudc_dma_send - Sends IN data using DMA.
+ * @ep: pointer to the usb device endpoint structure.
+ * @req: pointer to the usb request structure.
+ * @buffer: pointer to data to be sent.
+ * @length: number of bytes to send.
+ *
+ * Return: 0 on success, -EAGAIN if no buffer is free and error
+ *        code on failure.
+ *
+ * This function sends data using DMA.
+ */
+static int xudc_dma_send(struct xusb_ep *ep, struct xusb_req *req,
+                        u8 *buffer, u32 length)
+{
+       u32 *eprambase;
+       dma_addr_t src;
+       dma_addr_t dst;
+       struct xusb_udc *udc = ep->udc;
+
+       src = req->usb_req.dma + req->usb_req.actual;
+       if (req->usb_req.length)
+               dma_sync_single_for_device(udc->dev, src,
+                                          length, DMA_TO_DEVICE);
+       if (!ep->curbufnum && !ep->buffer0ready) {
+               /* Get the Buffer address and copy the transmit data.*/
+               eprambase = (u32 __force *)(udc->addr + ep->rambase);
+               dst = virt_to_phys(eprambase);
+               udc->write_fn(udc->addr, ep->offset +
+                             XUSB_EP_BUF0COUNT_OFFSET, length);
+               udc->write_fn(udc->addr, XUSB_DMA_CONTROL_OFFSET,
+                             XUSB_DMA_BRR_CTRL | (1 << ep->epnumber));
+               ep->buffer0ready = 1;
+               ep->curbufnum = 1;
+       } else if (ep->curbufnum && !ep->buffer1ready) {
+               /* Get the Buffer address and copy the transmit data.*/
+               eprambase = (u32 __force *)(udc->addr + ep->rambase +
+                            ep->ep_usb.maxpacket);
+               dst = virt_to_phys(eprambase);
+               udc->write_fn(udc->addr, ep->offset +
+                             XUSB_EP_BUF1COUNT_OFFSET, length);
+               udc->write_fn(udc->addr, XUSB_DMA_CONTROL_OFFSET,
+                             XUSB_DMA_BRR_CTRL | (1 << (ep->epnumber +
+                             XUSB_STATUS_EP_BUFF2_SHIFT)));
+               ep->buffer1ready = 1;
+               ep->curbufnum = 0;
+       } else {
+               /* None of ping pong buffers are ready currently .*/
+               return -EAGAIN;
+       }
+
+       return xudc_start_dma(ep, src, dst, length);
+}
+
+/**
+ * xudc_dma_receive - Receives OUT data using DMA.
+ * @ep: pointer to the usb device endpoint structure.
+ * @req: pointer to the usb request structure.
+ * @buffer: pointer to storage buffer of received data.
+ * @length: number of bytes to receive.
+ *
+ * Return: 0 on success, -EAGAIN if no buffer is free and error
+ *        code on failure.
+ *
+ * This function receives data using DMA.
+ */
+static int xudc_dma_receive(struct xusb_ep *ep, struct xusb_req *req,
+                           u8 *buffer, u32 length)
+{
+       u32 *eprambase;
+       dma_addr_t src;
+       dma_addr_t dst;
+       struct xusb_udc *udc = ep->udc;
+
+       dst = req->usb_req.dma + req->usb_req.actual;
+       if (!ep->curbufnum && !ep->buffer0ready) {
+               /* Get the Buffer address and copy the transmit data */
+               eprambase = (u32 __force *)(udc->addr + ep->rambase);
+               src = virt_to_phys(eprambase);
+               udc->write_fn(udc->addr, XUSB_DMA_CONTROL_OFFSET,
+                             XUSB_DMA_BRR_CTRL | XUSB_DMA_READ_FROM_DPRAM |
+                             (1 << ep->epnumber));
+               ep->buffer0ready = 1;
+               ep->curbufnum = 1;
+       } else if (ep->curbufnum && !ep->buffer1ready) {
+               /* Get the Buffer address and copy the transmit data */
+               eprambase = (u32 __force *)(udc->addr +
+                            ep->rambase + ep->ep_usb.maxpacket);
+               src = virt_to_phys(eprambase);
+               udc->write_fn(udc->addr, XUSB_DMA_CONTROL_OFFSET,
+                             XUSB_DMA_BRR_CTRL | XUSB_DMA_READ_FROM_DPRAM |
+                             (1 << (ep->epnumber +
+                             XUSB_STATUS_EP_BUFF2_SHIFT)));
+               ep->buffer1ready = 1;
+               ep->curbufnum = 0;
+       } else {
+               /* None of the ping-pong buffers are ready currently */
+               return -EAGAIN;
+       }
+
+       return xudc_start_dma(ep, src, dst, length);
+}
+
+/**
+ * xudc_eptxrx - Transmits or receives data to or from an endpoint.
+ * @ep: pointer to the usb endpoint configuration structure.
+ * @req: pointer to the usb request structure.
+ * @bufferptr: pointer to buffer containing the data to be sent.
+ * @bufferlen: The number of data bytes to be sent.
+ *
+ * Return: 0 on success, -EAGAIN if no buffer is free.
+ *
+ * This function copies the transmit/receive data to/from the end point buffer
+ * and enables the buffer for transmission/reception.
+ */
+static int xudc_eptxrx(struct xusb_ep *ep, struct xusb_req *req,
+                      u8 *bufferptr, u32 bufferlen)
+{
+       u32 *eprambase;
+       u32 bytestosend;
+       int rc = 0;
+       struct xusb_udc *udc = ep->udc;
+
+       bytestosend = bufferlen;
+       if (udc->dma_enabled) {
+               if (ep->is_in)
+                       rc = xudc_dma_send(ep, req, bufferptr, bufferlen);
+               else
+                       rc = xudc_dma_receive(ep, req, bufferptr, bufferlen);
+               return rc;
+       }
+       /* Put the transmit buffer into the correct ping-pong buffer.*/
+       if (!ep->curbufnum && !ep->buffer0ready) {
+               /* Get the Buffer address and copy the transmit data.*/
+               eprambase = (u32 __force *)(udc->addr + ep->rambase);
+               if (ep->is_in) {
+                       memcpy(eprambase, bufferptr, bytestosend);
+                       udc->write_fn(udc->addr, ep->offset +
+                                     XUSB_EP_BUF0COUNT_OFFSET, bufferlen);
+               } else {
+                       memcpy(bufferptr, eprambase, bytestosend);
+               }
+               /*
+                * Enable the buffer for transmission.
+                */
+               udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET,
+                             1 << ep->epnumber);
+               ep->buffer0ready = 1;
+               ep->curbufnum = 1;
+       } else if (ep->curbufnum && !ep->buffer1ready) {
+               /* Get the Buffer address and copy the transmit data.*/
+               eprambase = (u32 __force *)(udc->addr + ep->rambase +
+                            ep->ep_usb.maxpacket);
+               if (ep->is_in) {
+                       memcpy(eprambase, bufferptr, bytestosend);
+                       udc->write_fn(udc->addr, ep->offset +
+                                     XUSB_EP_BUF1COUNT_OFFSET, bufferlen);
+               } else {
+                       memcpy(bufferptr, eprambase, bytestosend);
+               }
+               /*
+                * Enable the buffer for transmission.
+                */
+               udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET,
+                             1 << (ep->epnumber + XUSB_STATUS_EP_BUFF2_SHIFT));
+               ep->buffer1ready = 1;
+               ep->curbufnum = 0;
+       } else {
+               /* None of the ping-pong buffers are ready currently */
+               return -EAGAIN;
+       }
+       return rc;
+}
+
+/**
+ * xudc_done - Exeutes the endpoint data transfer completion tasks.
+ * @ep: pointer to the usb device endpoint structure.
+ * @req: pointer to the usb request structure.
+ * @status: Status of the data transfer.
+ *
+ * Deletes the message from the queue and updates data transfer completion
+ * status.
+ */
+static void xudc_done(struct xusb_ep *ep, struct xusb_req *req, int status)
+{
+       struct xusb_udc *udc = ep->udc;
+
+       list_del_init(&req->queue);
+
+       if (req->usb_req.status == -EINPROGRESS)
+               req->usb_req.status = status;
+       else
+               status = req->usb_req.status;
+
+       if (status && status != -ESHUTDOWN)
+               dev_dbg(udc->dev, "%s done %p, status %d\n",
+                       ep->ep_usb.name, req, status);
+       /* unmap request if DMA is present*/
+       if (udc->dma_enabled && ep->epnumber && req->usb_req.length)
+               usb_gadget_unmap_request(&udc->gadget, &req->usb_req,
+                                        ep->is_in);
+
+       if (req->usb_req.complete) {
+               spin_unlock(&udc->lock);
+               req->usb_req.complete(&ep->ep_usb, &req->usb_req);
+               spin_lock(&udc->lock);
+       }
+}
+
+/**
+ * xudc_read_fifo - Reads the data from the given endpoint buffer.
+ * @ep: pointer to the usb device endpoint structure.
+ * @req: pointer to the usb request structure.
+ *
+ * Return: 0 if request is completed and -EAGAIN if not completed.
+ *
+ * Pulls OUT packet data from the endpoint buffer.
+ */
+static int xudc_read_fifo(struct xusb_ep *ep, struct xusb_req *req)
+{
+       u8 *buf;
+       u32 is_short, count, bufferspace;
+       u8 bufoffset;
+       u8 two_pkts = 0;
+       int ret;
+       int retval = -EAGAIN;
+       struct xusb_udc *udc = ep->udc;
+
+       if (ep->buffer0ready && ep->buffer1ready) {
+               dev_dbg(udc->dev, "Packet NOT ready!\n");
+               return retval;
+       }
+top:
+       if (ep->curbufnum)
+               bufoffset = XUSB_EP_BUF1COUNT_OFFSET;
+       else
+               bufoffset = XUSB_EP_BUF0COUNT_OFFSET;
+
+       count = udc->read_fn(udc->addr + ep->offset + bufoffset);
+
+       if (!ep->buffer0ready && !ep->buffer1ready)
+               two_pkts = 1;
+
+       buf = req->usb_req.buf + req->usb_req.actual;
+       prefetchw(buf);
+       bufferspace = req->usb_req.length - req->usb_req.actual;
+       is_short = count < ep->ep_usb.maxpacket;
+
+       if (unlikely(!bufferspace)) {
+               /*
+                * This happens when the driver's buffer
+                * is smaller than what the host sent.
+                * discard the extra data.
+                */
+               if (req->usb_req.status != -EOVERFLOW)
+                       dev_dbg(udc->dev, "%s overflow %d\n",
+                               ep->ep_usb.name, count);
+               req->usb_req.status = -EOVERFLOW;
+               xudc_done(ep, req, -EOVERFLOW);
+               return 0;
+       }
+
+       ret = xudc_eptxrx(ep, req, buf, count);
+       switch (ret) {
+       case 0:
+               req->usb_req.actual += min(count, bufferspace);
+               dev_dbg(udc->dev, "read %s, %d bytes%s req %p %d/%d\n",
+                       ep->ep_usb.name, count, is_short ? "/S" : "", req,
+                       req->usb_req.actual, req->usb_req.length);
+               bufferspace -= count;
+               /* Completion */
+               if ((req->usb_req.actual == req->usb_req.length) || is_short) {
+                       if (udc->dma_enabled && req->usb_req.length)
+                               dma_sync_single_for_cpu(udc->dev,
+                                                       req->usb_req.dma,
+                                                       req->usb_req.actual,
+                                                       DMA_FROM_DEVICE);
+                       xudc_done(ep, req, 0);
+                       return 0;
+               }
+               if (two_pkts) {
+                       two_pkts = 0;
+                       goto top;
+               }
+               break;
+       case -EAGAIN:
+               dev_dbg(udc->dev, "receive busy\n");
+               break;
+       case -EINVAL:
+       case -ETIMEDOUT:
+               /* DMA error, dequeue the request */
+               xudc_done(ep, req, -ECONNRESET);
+               retval = 0;
+               break;
+       }
+
+       return retval;
+}
+
+/**
+ * xudc_write_fifo - Writes data into the given endpoint buffer.
+ * @ep: pointer to the usb device endpoint structure.
+ * @req: pointer to the usb request structure.
+ *
+ * Return: 0 if request is completed and -EAGAIN if not completed.
+ *
+ * Loads endpoint buffer for an IN packet.
+ */
+static int xudc_write_fifo(struct xusb_ep *ep, struct xusb_req *req)
+{
+       u32 max;
+       u32 length;
+       int ret;
+       int retval = -EAGAIN;
+       struct xusb_udc *udc = ep->udc;
+       int is_last, is_short = 0;
+       u8 *buf;
+
+       max = le16_to_cpu(ep->desc->wMaxPacketSize);
+       buf = req->usb_req.buf + req->usb_req.actual;
+       prefetch(buf);
+       length = req->usb_req.length - req->usb_req.actual;
+       length = min(length, max);
+
+       ret = xudc_eptxrx(ep, req, buf, length);
+       switch (ret) {
+       case 0:
+               req->usb_req.actual += length;
+               if (unlikely(length != max)) {
+                       is_last = is_short = 1;
+               } else {
+                       if (likely(req->usb_req.length !=
+                                  req->usb_req.actual) || req->usb_req.zero)
+                               is_last = 0;
+                       else
+                               is_last = 1;
+               }
+               dev_dbg(udc->dev, "%s: wrote %s %d bytes%s%s %d left %p\n",
+                       __func__, ep->ep_usb.name, length, is_last ? "/L" : "",
+                       is_short ? "/S" : "",
+                       req->usb_req.length - req->usb_req.actual, req);
+               /* completion */
+               if (is_last) {
+                       xudc_done(ep, req, 0);
+                       retval = 0;
+               }
+               break;
+       case -EAGAIN:
+               dev_dbg(udc->dev, "Send busy\n");
+               break;
+       case -EINVAL:
+       case -ETIMEDOUT:
+               /* DMA error, dequeue the request */
+               xudc_done(ep, req, -ECONNRESET);
+               retval = 0;
+               break;
+       }
+
+       return retval;
+}
+
+/**
+ * xudc_nuke - Cleans up the data transfer message list.
+ * @ep: pointer to the usb device endpoint structure.
+ * @status: Status of the data transfer.
+ */
+static void xudc_nuke(struct xusb_ep *ep, int status)
+{
+       struct xusb_req *req;
+
+       while (!list_empty(&ep->queue)) {
+               req = list_first_entry(&ep->queue, struct xusb_req, queue);
+               xudc_done(ep, req, status);
+       }
+}
+
+/**
+ * xudc_ep_set_halt - Stalls/unstalls the given endpoint.
+ * @_ep: pointer to the usb device endpoint structure.
+ * @value: value to indicate stall/unstall.
+ *
+ * Return: 0 for success and error value on failure
+ */
+static int xudc_ep_set_halt(struct usb_ep *_ep, int value)
+{
+       struct xusb_ep *ep = to_xusb_ep(_ep);
+       struct xusb_udc *udc;
+       unsigned long flags;
+       u32 epcfgreg;
+
+       if (!_ep || (!ep->desc && ep->epnumber)) {
+               pr_debug("%s: bad ep or descriptor\n", __func__);
+               return -EINVAL;
+       }
+       udc = ep->udc;
+
+       if (ep->is_in && (!list_empty(&ep->queue)) && value) {
+               dev_dbg(udc->dev, "requests pending can't halt\n");
+               return -EAGAIN;
+       }
+
+       if (ep->buffer0ready || ep->buffer1ready) {
+               dev_dbg(udc->dev, "HW buffers busy can't halt\n");
+               return -EAGAIN;
+       }
+
+       spin_lock_irqsave(&udc->lock, flags);
+
+       if (value) {
+               /* Stall the device.*/
+               epcfgreg = udc->read_fn(udc->addr + ep->offset);
+               epcfgreg |= XUSB_EP_CFG_STALL_MASK;
+               udc->write_fn(udc->addr, ep->offset, epcfgreg);
+       } else {
+               /* Unstall the device.*/
+               epcfgreg = udc->read_fn(udc->addr + ep->offset);
+               epcfgreg &= ~XUSB_EP_CFG_STALL_MASK;
+               udc->write_fn(udc->addr, ep->offset, epcfgreg);
+               if (ep->epnumber) {
+                       /* Reset the toggle bit.*/
+                       epcfgreg = udc->read_fn(ep->udc->addr + ep->offset);
+                       epcfgreg &= ~XUSB_EP_CFG_DATA_TOGGLE_MASK;
+                       udc->write_fn(udc->addr, ep->offset, epcfgreg);
+               }
+       }
+
+       spin_unlock_irqrestore(&udc->lock, flags);
+       return 0;
+}
+
+/**
+ * xudc_ep_enable - Enables the given endpoint.
+ * @ep: pointer to the xusb endpoint structure.
+ * @desc: pointer to usb endpoint descriptor.
+ *
+ * Return: 0 for success and error value on failure
+ */
+static int __xudc_ep_enable(struct xusb_ep *ep,
+                           const struct usb_endpoint_descriptor *desc)
+{
+       struct xusb_udc *udc = ep->udc;
+       u32 tmp;
+       u32 epcfg;
+       u32 ier;
+       u16 maxpacket;
+
+       ep->is_in = ((desc->bEndpointAddress & USB_DIR_IN) != 0);
+       /* Bit 3...0:endpoint number */
+       ep->epnumber = (desc->bEndpointAddress & 0x0f);
+       ep->desc = desc;
+       ep->ep_usb.desc = desc;
+       tmp = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
+       ep->ep_usb.maxpacket = maxpacket = le16_to_cpu(desc->wMaxPacketSize);
+
+       switch (tmp) {
+       case USB_ENDPOINT_XFER_CONTROL:
+               dev_dbg(udc->dev, "only one control endpoint\n");
+               /* NON- ISO */
+               ep->is_iso = 0;
+               return -EINVAL;
+       case USB_ENDPOINT_XFER_INT:
+               /* NON- ISO */
+               ep->is_iso = 0;
+               if (maxpacket > 64) {
+                       dev_dbg(udc->dev, "bogus maxpacket %d\n", maxpacket);
+                       return -EINVAL;
+               }
+               break;
+       case USB_ENDPOINT_XFER_BULK:
+               /* NON- ISO */
+               ep->is_iso = 0;
+               if (!(is_power_of_2(maxpacket) && maxpacket >= 8 &&
+                               maxpacket <= 512)) {
+                       dev_dbg(udc->dev, "bogus maxpacket %d\n", maxpacket);
+                       return -EINVAL;
+               }
+               break;
+       case USB_ENDPOINT_XFER_ISOC:
+               /* ISO */
+               ep->is_iso = 1;
+               break;
+       }
+
+       ep->buffer0ready = 0;
+       ep->buffer1ready = 0;
+       ep->curbufnum = 0;
+       ep->rambase = rambase[ep->epnumber];
+       xudc_epconfig(ep, udc);
+
+       dev_dbg(udc->dev, "Enable Endpoint %d max pkt is %d\n",
+               ep->epnumber, maxpacket);
+
+       /* Enable the End point.*/
+       epcfg = udc->read_fn(udc->addr + ep->offset);
+       epcfg |= XUSB_EP_CFG_VALID_MASK;
+       udc->write_fn(udc->addr, ep->offset, epcfg);
+       if (ep->epnumber)
+               ep->rambase <<= 2;
+
+       /* Enable buffer completion interrupts for endpoint */
+       ier = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
+       ier |= (XUSB_STATUS_INTR_BUFF_COMP_SHIFT_MASK << ep->epnumber);
+       udc->write_fn(udc->addr, XUSB_IER_OFFSET, ier);
+
+       /* for OUT endpoint set buffers ready to receive */
+       if (ep->epnumber && !ep->is_in) {
+               udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET,
+                             1 << ep->epnumber);
+               ep->buffer0ready = 1;
+               udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET,
+                            (1 << (ep->epnumber +
+                             XUSB_STATUS_EP_BUFF2_SHIFT)));
+               ep->buffer1ready = 1;
+       }
+
+       return 0;
+}
+
+/**
+ * xudc_ep_enable - Enables the given endpoint.
+ * @_ep: pointer to the usb endpoint structure.
+ * @desc: pointer to usb endpoint descriptor.
+ *
+ * Return: 0 for success and error value on failure
+ */
+static int xudc_ep_enable(struct usb_ep *_ep,
+                         const struct usb_endpoint_descriptor *desc)
+{
+       struct xusb_ep *ep;
+       struct xusb_udc *udc;
+       unsigned long flags;
+       int ret;
+
+       if (!_ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
+               pr_debug("%s: bad ep or descriptor\n", __func__);
+               return -EINVAL;
+       }
+
+       ep = to_xusb_ep(_ep);
+       udc = ep->udc;
+
+       if (!udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
+               dev_dbg(udc->dev, "bogus device state\n");
+               return -ESHUTDOWN;
+       }
+
+       spin_lock_irqsave(&udc->lock, flags);
+       ret = __xudc_ep_enable(ep, desc);
+       spin_unlock_irqrestore(&udc->lock, flags);
+
+       return ret;
+}
+
+/**
+ * xudc_ep_disable - Disables the given endpoint.
+ * @_ep: pointer to the usb endpoint structure.
+ *
+ * Return: 0 for success and error value on failure
+ */
+static int xudc_ep_disable(struct usb_ep *_ep)
+{
+       struct xusb_ep *ep;
+       unsigned long flags;
+       u32 epcfg;
+       struct xusb_udc *udc;
+
+       if (!_ep) {
+               pr_debug("%s: invalid ep\n", __func__);
+               return -EINVAL;
+       }
+
+       ep = to_xusb_ep(_ep);
+       udc = ep->udc;
+
+       spin_lock_irqsave(&udc->lock, flags);
+
+       xudc_nuke(ep, -ESHUTDOWN);
+
+       /* Restore the endpoint's pristine config */
+       ep->desc = NULL;
+       ep->ep_usb.desc = NULL;
+
+       dev_dbg(udc->dev, "USB Ep %d disable\n ", ep->epnumber);
+       /* Disable the endpoint.*/
+       epcfg = udc->read_fn(udc->addr + ep->offset);
+       epcfg &= ~XUSB_EP_CFG_VALID_MASK;
+       udc->write_fn(udc->addr, ep->offset, epcfg);
+
+       spin_unlock_irqrestore(&udc->lock, flags);
+       return 0;
+}
+
+/**
+ * xudc_ep_alloc_request - Initializes the request queue.
+ * @_ep: pointer to the usb endpoint structure.
+ * @gfp_flags: Flags related to the request call.
+ *
+ * Return: pointer to request structure on success and a NULL on failure.
+ */
+static struct usb_request *xudc_ep_alloc_request(struct usb_ep *_ep,
+                                                gfp_t gfp_flags)
+{
+       struct xusb_ep *ep = to_xusb_ep(_ep);
+       struct xusb_udc *udc;
+       struct xusb_req *req;
+
+       udc = ep->udc;
+       req = kzalloc(sizeof(*req), gfp_flags);
+       if (!req) {
+               dev_err(udc->dev, "%s:not enough memory", __func__);
+               return NULL;
+       }
+
+       req->ep = ep;
+       INIT_LIST_HEAD(&req->queue);
+       return &req->usb_req;
+}
+
+/**
+ * xudc_free_request - Releases the request from queue.
+ * @_ep: pointer to the usb device endpoint structure.
+ * @_req: pointer to the usb request structure.
+ */
+static void xudc_free_request(struct usb_ep *_ep, struct usb_request *_req)
+{
+       struct xusb_req *req = to_xusb_req(_req);
+
+       kfree(req);
+}
+
+/**
+ * xudc_ep0_queue - Adds the request to endpoint 0 queue.
+ * @ep0: pointer to the xusb endpoint 0 structure.
+ * @req: pointer to the xusb request structure.
+ *
+ * Return: 0 for success and error value on failure
+ */
+static int __xudc_ep0_queue(struct xusb_ep *ep0, struct xusb_req *req)
+{
+       struct xusb_udc *udc = ep0->udc;
+       u32 length;
+       u8 *corebuf;
+
+       if (!udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
+               dev_dbg(udc->dev, "%s, bogus device state\n", __func__);
+               return -EINVAL;
+       }
+       if (!list_empty(&ep0->queue)) {
+               dev_dbg(udc->dev, "%s:ep0 busy\n", __func__);
+               return -EBUSY;
+       }
+
+       req->usb_req.status = -EINPROGRESS;
+       req->usb_req.actual = 0;
+
+       list_add_tail(&req->queue, &ep0->queue);
+
+       if (udc->setup.bRequestType & USB_DIR_IN) {
+               prefetch(req->usb_req.buf);
+               length = req->usb_req.length;
+               corebuf = (void __force *) ((ep0->rambase << 2) +
+                          udc->addr);
+               length = req->usb_req.actual = min_t(u32, length,
+                                                    EP0_MAX_PACKET);
+               memcpy(corebuf, req->usb_req.buf, length);
+               udc->write_fn(udc->addr, XUSB_EP_BUF0COUNT_OFFSET, length);
+               udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET, 1);
+       } else {
+               if (udc->setup.wLength) {
+                       /* Enable EP0 buffer to receive data */
+                       udc->write_fn(udc->addr, XUSB_EP_BUF0COUNT_OFFSET, 0);
+                       udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET, 1);
+               } else {
+                       xudc_wrstatus(udc);
+               }
+       }
+
+       return 0;
+}
+
+/**
+ * xudc_ep0_queue - Adds the request to endpoint 0 queue.
+ * @_ep: pointer to the usb endpoint 0 structure.
+ * @_req: pointer to the usb request structure.
+ * @gfp_flags: Flags related to the request call.
+ *
+ * Return: 0 for success and error value on failure
+ */
+static int xudc_ep0_queue(struct usb_ep *_ep, struct usb_request *_req,
+                         gfp_t gfp_flags)
+{
+       struct xusb_req *req    = to_xusb_req(_req);
+       struct xusb_ep  *ep0    = to_xusb_ep(_ep);
+       struct xusb_udc *udc    = ep0->udc;
+       unsigned long flags;
+       int ret;
+
+       spin_lock_irqsave(&udc->lock, flags);
+       ret = __xudc_ep0_queue(ep0, req);
+       spin_unlock_irqrestore(&udc->lock, flags);
+
+       return ret;
+}
+
+/**
+ * xudc_ep_queue - Adds the request to endpoint queue.
+ * @_ep: pointer to the usb endpoint structure.
+ * @_req: pointer to the usb request structure.
+ * @gfp_flags: Flags related to the request call.
+ *
+ * Return: 0 for success and error value on failure
+ */
+static int xudc_ep_queue(struct usb_ep *_ep, struct usb_request *_req,
+                        gfp_t gfp_flags)
+{
+       struct xusb_req *req = to_xusb_req(_req);
+       struct xusb_ep  *ep  = to_xusb_ep(_ep);
+       struct xusb_udc *udc = ep->udc;
+       int  ret;
+       unsigned long flags;
+
+       if (!ep->desc) {
+               dev_dbg(udc->dev, "%s:queing request to disabled %s\n",
+                       __func__, ep->name);
+               return -ESHUTDOWN;
+       }
+
+       if (!udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
+               dev_dbg(udc->dev, "%s, bogus device state\n", __func__);
+               return -EINVAL;
+       }
+
+       spin_lock_irqsave(&udc->lock, flags);
+
+       _req->status = -EINPROGRESS;
+       _req->actual = 0;
+
+       if (udc->dma_enabled) {
+               ret = usb_gadget_map_request(&udc->gadget, &req->usb_req,
+                                            ep->is_in);
+               if (ret) {
+                       dev_dbg(udc->dev, "gadget_map failed ep%d\n",
+                               ep->epnumber);
+                       spin_unlock_irqrestore(&udc->lock, flags);
+                       return -EAGAIN;
+               }
+       }
+
+       if (list_empty(&ep->queue)) {
+               if (ep->is_in) {
+                       dev_dbg(udc->dev, "xudc_write_fifo from ep_queue\n");
+                       if (!xudc_write_fifo(ep, req))
+                               req = NULL;
+               } else {
+                       dev_dbg(udc->dev, "xudc_read_fifo from ep_queue\n");
+                       if (!xudc_read_fifo(ep, req))
+                               req = NULL;
+               }
+       }
+
+       if (req != NULL)
+               list_add_tail(&req->queue, &ep->queue);
+
+       spin_unlock_irqrestore(&udc->lock, flags);
+       return 0;
+}
+
+/**
+ * xudc_ep_dequeue - Removes the request from the queue.
+ * @_ep: pointer to the usb device endpoint structure.
+ * @_req: pointer to the usb request structure.
+ *
+ * Return: 0 for success and error value on failure
+ */
+static int xudc_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
+{
+       struct xusb_ep *ep      = to_xusb_ep(_ep);
+       struct xusb_req *req    = to_xusb_req(_req);
+       struct xusb_udc *udc    = ep->udc;
+       unsigned long flags;
+
+       spin_lock_irqsave(&udc->lock, flags);
+       /* Make sure it's actually queued on this endpoint */
+       list_for_each_entry(req, &ep->queue, queue) {
+               if (&req->usb_req == _req)
+                       break;
+       }
+       if (&req->usb_req != _req) {
+               spin_unlock_irqrestore(&ep->udc->lock, flags);
+               return -EINVAL;
+       }
+       xudc_done(ep, req, -ECONNRESET);
+       spin_unlock_irqrestore(&udc->lock, flags);
+
+       return 0;
+}
+
+/**
+ * xudc_ep0_enable - Enables the given endpoint.
+ * @ep: pointer to the usb endpoint structure.
+ * @desc: pointer to usb endpoint descriptor.
+ *
+ * Return: error always.
+ *
+ * endpoint 0 enable should not be called by gadget layer.
+ */
+static int xudc_ep0_enable(struct usb_ep *ep,
+                          const struct usb_endpoint_descriptor *desc)
+{
+       return -EINVAL;
+}
+
+/**
+ * xudc_ep0_disable - Disables the given endpoint.
+ * @ep: pointer to the usb endpoint structure.
+ *
+ * Return: error always.
+ *
+ * endpoint 0 disable should not be called by gadget layer.
+ */
+static int xudc_ep0_disable(struct usb_ep *ep)
+{
+       return -EINVAL;
+}
+
+static const struct usb_ep_ops xusb_ep0_ops = {
+       .enable         = xudc_ep0_enable,
+       .disable        = xudc_ep0_disable,
+       .alloc_request  = xudc_ep_alloc_request,
+       .free_request   = xudc_free_request,
+       .queue          = xudc_ep0_queue,
+       .dequeue        = xudc_ep_dequeue,
+       .set_halt       = xudc_ep_set_halt,
+};
+
+static const struct usb_ep_ops xusb_ep_ops = {
+       .enable         = xudc_ep_enable,
+       .disable        = xudc_ep_disable,
+       .alloc_request  = xudc_ep_alloc_request,
+       .free_request   = xudc_free_request,
+       .queue          = xudc_ep_queue,
+       .dequeue        = xudc_ep_dequeue,
+       .set_halt       = xudc_ep_set_halt,
+};
+
+/**
+ * xudc_get_frame - Reads the current usb frame number.
+ * @gadget: pointer to the usb gadget structure.
+ *
+ * Return: current frame number for success and error value on failure.
+ */
+static int xudc_get_frame(struct usb_gadget *gadget)
+{
+       struct xusb_udc *udc;
+       int frame;
+
+       if (!gadget)
+               return -ENODEV;
+
+       udc = to_udc(gadget);
+       frame = udc->read_fn(udc->addr + XUSB_FRAMENUM_OFFSET);
+       return frame;
+}
+
+/**
+ * xudc_wakeup - Send remote wakeup signal to host
+ * @gadget: pointer to the usb gadget structure.
+ *
+ * Return: 0 on success and error on failure
+ */
+static int xudc_wakeup(struct usb_gadget *gadget)
+{
+       struct xusb_udc *udc = to_udc(gadget);
+       u32 crtlreg;
+       int status = -EINVAL;
+       unsigned long flags;
+
+       spin_lock_irqsave(&udc->lock, flags);
+
+       /* Remote wake up not enabled by host */
+       if (!udc->remote_wkp)
+               goto done;
+
+       crtlreg = udc->read_fn(udc->addr + XUSB_CONTROL_OFFSET);
+       crtlreg |= XUSB_CONTROL_USB_RMTWAKE_MASK;
+       /* set remote wake up bit */
+       udc->write_fn(udc->addr, XUSB_CONTROL_OFFSET, crtlreg);
+       /*
+        * wait for a while and reset remote wake up bit since this bit
+        * is not cleared by HW after sending remote wakeup to host.
+        */
+       mdelay(2);
+
+       crtlreg &= ~XUSB_CONTROL_USB_RMTWAKE_MASK;
+       udc->write_fn(udc->addr, XUSB_CONTROL_OFFSET, crtlreg);
+       status = 0;
+done:
+       spin_unlock_irqrestore(&udc->lock, flags);
+       return status;
+}
+
+/**
+ * xudc_pullup - start/stop USB traffic
+ * @gadget: pointer to the usb gadget structure.
+ * @is_on: flag to start or stop
+ *
+ * Return: 0 always
+ *
+ * This function starts/stops SIE engine of IP based on is_on.
+ */
+static int xudc_pullup(struct usb_gadget *gadget, int is_on)
+{
+       struct xusb_udc *udc = to_udc(gadget);
+       unsigned long flags;
+       u32 crtlreg;
+
+       spin_lock_irqsave(&udc->lock, flags);
+
+       crtlreg = udc->read_fn(udc->addr + XUSB_CONTROL_OFFSET);
+       if (is_on)
+               crtlreg |= XUSB_CONTROL_USB_READY_MASK;
+       else
+               crtlreg &= ~XUSB_CONTROL_USB_READY_MASK;
+
+       udc->write_fn(udc->addr, XUSB_CONTROL_OFFSET, crtlreg);
+
+       spin_unlock_irqrestore(&udc->lock, flags);
+
+       return 0;
+}
+
+/**
+ * xudc_eps_init - initialize endpoints.
+ * @udc: pointer to the usb device controller structure.
+ */
+static void xudc_eps_init(struct xusb_udc *udc)
+{
+       u32 ep_number;
+
+       INIT_LIST_HEAD(&udc->gadget.ep_list);
+
+       for (ep_number = 0; ep_number < XUSB_MAX_ENDPOINTS; ep_number++) {
+               struct xusb_ep *ep = &udc->ep[ep_number];
+
+               if (ep_number) {
+                       list_add_tail(&ep->ep_usb.ep_list,
+                                     &udc->gadget.ep_list);
+                       usb_ep_set_maxpacket_limit(&ep->ep_usb,
+                                                 (unsigned short) ~0);
+                       snprintf(ep->name, EPNAME_SIZE, "ep%d", ep_number);
+                       ep->ep_usb.name = ep->name;
+                       ep->ep_usb.ops = &xusb_ep_ops;
+               } else {
+                       ep->ep_usb.name = ep0name;
+                       usb_ep_set_maxpacket_limit(&ep->ep_usb, EP0_MAX_PACKET);
+                       ep->ep_usb.ops = &xusb_ep0_ops;
+               }
+
+               ep->udc = udc;
+               ep->epnumber = ep_number;
+               ep->desc = NULL;
+               /*
+                * The configuration register address offset between
+                * each endpoint is 0x10.
+                */
+               ep->offset = XUSB_EP0_CONFIG_OFFSET + (ep_number * 0x10);
+               ep->is_in = 0;
+               ep->is_iso = 0;
+               ep->maxpacket = 0;
+               xudc_epconfig(ep, udc);
+
+               /* Initialize one queue per endpoint */
+               INIT_LIST_HEAD(&ep->queue);
+       }
+}
+
+/**
+ * xudc_stop_activity - Stops any further activity on the device.
+ * @udc: pointer to the usb device controller structure.
+ */
+static void xudc_stop_activity(struct xusb_udc *udc)
+{
+       int i;
+       struct xusb_ep *ep;
+
+       for (i = 0; i < XUSB_MAX_ENDPOINTS; i++) {
+               ep = &udc->ep[i];
+               xudc_nuke(ep, -ESHUTDOWN);
+       }
+}
+
+/**
+ * xudc_start - Starts the device.
+ * @gadget: pointer to the usb gadget structure
+ * @driver: pointer to gadget driver structure
+ *
+ * Return: zero on success and error on failure
+ */
+static int xudc_start(struct usb_gadget *gadget,
+                     struct usb_gadget_driver *driver)
+{
+       struct xusb_udc *udc    = to_udc(gadget);
+       struct xusb_ep *ep0     = &udc->ep[XUSB_EP_NUMBER_ZERO];
+       const struct usb_endpoint_descriptor *desc = &config_bulk_out_desc;
+       unsigned long flags;
+       int ret = 0;
+
+       spin_lock_irqsave(&udc->lock, flags);
+
+       if (udc->driver) {
+               dev_err(udc->dev, "%s is already bound to %s\n",
+                       udc->gadget.name, udc->driver->driver.name);
+               ret = -EBUSY;
+               goto err;
+       }
+
+       /* hook up the driver */
+       udc->driver = driver;
+       udc->gadget.speed = driver->max_speed;
+
+       /* Enable the control endpoint. */
+       ret = __xudc_ep_enable(ep0, desc);
+
+       /* Set device address and remote wakeup to 0 */
+       udc->write_fn(udc->addr, XUSB_ADDRESS_OFFSET, 0);
+       udc->remote_wkp = 0;
+err:
+       spin_unlock_irqrestore(&udc->lock, flags);
+       return ret;
+}
+
+/**
+ * xudc_stop - stops the device.
+ * @gadget: pointer to the usb gadget structure
+ * @driver: pointer to usb gadget driver structure
+ *
+ * Return: zero always
+ */
+static int xudc_stop(struct usb_gadget *gadget,
+                    struct usb_gadget_driver *driver)
+{
+       struct xusb_udc *udc = to_udc(gadget);
+       unsigned long flags;
+
+       spin_lock_irqsave(&udc->lock, flags);
+
+       udc->gadget.speed = USB_SPEED_UNKNOWN;
+       udc->driver = NULL;
+
+       /* Set device address and remote wakeup to 0 */
+       udc->write_fn(udc->addr, XUSB_ADDRESS_OFFSET, 0);
+       udc->remote_wkp = 0;
+
+       xudc_stop_activity(udc);
+
+       spin_unlock_irqrestore(&udc->lock, flags);
+
+       return 0;
+}
+
+static const struct usb_gadget_ops xusb_udc_ops = {
+       .get_frame      = xudc_get_frame,
+       .wakeup         = xudc_wakeup,
+       .pullup         = xudc_pullup,
+       .udc_start      = xudc_start,
+       .udc_stop       = xudc_stop,
+};
+
+/**
+ * xudc_clear_stall_all_ep - clears stall of every endpoint.
+ * @udc: pointer to the udc structure.
+ */
+static void xudc_clear_stall_all_ep(struct xusb_udc *udc)
+{
+       struct xusb_ep *ep;
+       u32 epcfgreg;
+       int i;
+
+       for (i = 0; i < XUSB_MAX_ENDPOINTS; i++) {
+               ep = &udc->ep[i];
+               epcfgreg = udc->read_fn(udc->addr + ep->offset);
+               epcfgreg &= ~XUSB_EP_CFG_STALL_MASK;
+               udc->write_fn(udc->addr, ep->offset, epcfgreg);
+               if (ep->epnumber) {
+                       /* Reset the toggle bit.*/
+                       epcfgreg = udc->read_fn(udc->addr + ep->offset);
+                       epcfgreg &= ~XUSB_EP_CFG_DATA_TOGGLE_MASK;
+                       udc->write_fn(udc->addr, ep->offset, epcfgreg);
+               }
+       }
+}
+
+/**
+ * xudc_startup_handler - The usb device controller interrupt handler.
+ * @udc: pointer to the udc structure.
+ * @intrstatus: The mask value containing the interrupt sources.
+ *
+ * This function handles the RESET,SUSPEND,RESUME and DISCONNECT interrupts.
+ */
+static void xudc_startup_handler(struct xusb_udc *udc, u32 intrstatus)
+{
+       u32 intrreg;
+
+       if (intrstatus & XUSB_STATUS_RESET_MASK) {
+
+               dev_dbg(udc->dev, "Reset\n");
+
+               if (intrstatus & XUSB_STATUS_HIGH_SPEED_MASK)
+                       udc->gadget.speed = USB_SPEED_HIGH;
+               else
+                       udc->gadget.speed = USB_SPEED_FULL;
+
+               xudc_stop_activity(udc);
+               xudc_clear_stall_all_ep(udc);
+               udc->write_fn(udc->addr, XUSB_TESTMODE_OFFSET, 0);
+
+               /* Set device address and remote wakeup to 0 */
+               udc->write_fn(udc->addr, XUSB_ADDRESS_OFFSET, 0);
+               udc->remote_wkp = 0;
+
+               /* Enable the suspend, resume and disconnect */
+               intrreg = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
+               intrreg |= XUSB_STATUS_SUSPEND_MASK | XUSB_STATUS_RESUME_MASK |
+                          XUSB_STATUS_DISCONNECT_MASK;
+               udc->write_fn(udc->addr, XUSB_IER_OFFSET, intrreg);
+       }
+       if (intrstatus & XUSB_STATUS_SUSPEND_MASK) {
+
+               dev_dbg(udc->dev, "Suspend\n");
+
+               /* Enable the reset, resume and disconnect */
+               intrreg = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
+               intrreg |= XUSB_STATUS_RESET_MASK | XUSB_STATUS_RESUME_MASK |
+                          XUSB_STATUS_DISCONNECT_MASK;
+               udc->write_fn(udc->addr, XUSB_IER_OFFSET, intrreg);
+
+               udc->usb_state = USB_STATE_SUSPENDED;
+
+               if (udc->driver->suspend) {
+                       spin_unlock(&udc->lock);
+                       udc->driver->suspend(&udc->gadget);
+                       spin_lock(&udc->lock);
+               }
+       }
+       if (intrstatus & XUSB_STATUS_RESUME_MASK) {
+               bool condition = (udc->usb_state != USB_STATE_SUSPENDED);
+
+               dev_WARN_ONCE(udc->dev, condition,
+                               "Resume IRQ while not suspended\n");
+
+               dev_dbg(udc->dev, "Resume\n");
+
+               /* Enable the reset, suspend and disconnect */
+               intrreg = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
+               intrreg |= XUSB_STATUS_RESET_MASK | XUSB_STATUS_SUSPEND_MASK |
+                          XUSB_STATUS_DISCONNECT_MASK;
+               udc->write_fn(udc->addr, XUSB_IER_OFFSET, intrreg);
+
+               udc->usb_state = 0;
+
+               if (udc->driver->resume) {
+                       spin_unlock(&udc->lock);
+                       udc->driver->resume(&udc->gadget);
+                       spin_lock(&udc->lock);
+               }
+       }
+       if (intrstatus & XUSB_STATUS_DISCONNECT_MASK) {
+
+               dev_dbg(udc->dev, "Disconnect\n");
+
+               /* Enable the reset, resume and suspend */
+               intrreg = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
+               intrreg |= XUSB_STATUS_RESET_MASK | XUSB_STATUS_RESUME_MASK |
+                          XUSB_STATUS_SUSPEND_MASK;
+               udc->write_fn(udc->addr, XUSB_IER_OFFSET, intrreg);
+
+               if (udc->driver && udc->driver->disconnect) {
+                       spin_unlock(&udc->lock);
+                       udc->driver->disconnect(&udc->gadget);
+                       spin_lock(&udc->lock);
+               }
+       }
+}
+
+/**
+ * xudc_ep0_stall - Stall endpoint zero.
+ * @udc: pointer to the udc structure.
+ *
+ * This function stalls endpoint zero.
+ */
+static void xudc_ep0_stall(struct xusb_udc *udc)
+{
+       u32 epcfgreg;
+       struct xusb_ep *ep0 = &udc->ep[XUSB_EP_NUMBER_ZERO];
+
+       epcfgreg = udc->read_fn(udc->addr + ep0->offset);
+       epcfgreg |= XUSB_EP_CFG_STALL_MASK;
+       udc->write_fn(udc->addr, ep0->offset, epcfgreg);
+}
+
+/**
+ * xudc_setaddress - executes SET_ADDRESS command
+ * @udc: pointer to the udc structure.
+ *
+ * This function executes USB SET_ADDRESS command
+ */
+static void xudc_setaddress(struct xusb_udc *udc)
+{
+       struct xusb_ep *ep0     = &udc->ep[0];
+       struct xusb_req *req    = udc->req;
+       int ret;
+
+       req->usb_req.length = 0;
+       ret = __xudc_ep0_queue(ep0, req);
+       if (ret == 0)
+               return;
+
+       dev_err(udc->dev, "Can't respond to SET ADDRESS request\n");
+       xudc_ep0_stall(udc);
+}
+
+/**
+ * xudc_getstatus - executes GET_STATUS command
+ * @udc: pointer to the udc structure.
+ *
+ * This function executes USB GET_STATUS command
+ */
+static void xudc_getstatus(struct xusb_udc *udc)
+{
+       struct xusb_ep *ep0     = &udc->ep[0];
+       struct xusb_req *req    = udc->req;
+       struct xusb_ep *target_ep;
+       u16 status = 0;
+       u32 epcfgreg;
+       int epnum;
+       u32 halt;
+       int ret;
+
+       switch (udc->setup.bRequestType & USB_RECIP_MASK) {
+       case USB_RECIP_DEVICE:
+               /* Get device status */
+               status = 1 << USB_DEVICE_SELF_POWERED;
+               if (udc->remote_wkp)
+                       status |= (1 << USB_DEVICE_REMOTE_WAKEUP);
+               break;
+       case USB_RECIP_INTERFACE:
+               break;
+       case USB_RECIP_ENDPOINT:
+               epnum = udc->setup.wIndex & USB_ENDPOINT_NUMBER_MASK;
+               target_ep = &udc->ep[epnum];
+               epcfgreg = udc->read_fn(udc->addr + target_ep->offset);
+               halt = epcfgreg & XUSB_EP_CFG_STALL_MASK;
+               if (udc->setup.wIndex & USB_DIR_IN) {
+                       if (!target_ep->is_in)
+                               goto stall;
+               } else {
+                       if (target_ep->is_in)
+                               goto stall;
+               }
+               if (halt)
+                       status = 1 << USB_ENDPOINT_HALT;
+               break;
+       default:
+               goto stall;
+       }
+
+       req->usb_req.length = 2;
+       *(u16 *)req->usb_req.buf = cpu_to_le16(status);
+       ret = __xudc_ep0_queue(ep0, req);
+       if (ret == 0)
+               return;
+stall:
+       dev_err(udc->dev, "Can't respond to getstatus request\n");
+       xudc_ep0_stall(udc);
+}
+
+/**
+ * xudc_set_clear_feature - Executes the set feature and clear feature commands.
+ * @udc: pointer to the usb device controller structure.
+ *
+ * Processes the SET_FEATURE and CLEAR_FEATURE commands.
+ */
+static void xudc_set_clear_feature(struct xusb_udc *udc)
+{
+       struct xusb_ep *ep0     = &udc->ep[0];
+       struct xusb_req *req    = udc->req;
+       struct xusb_ep *target_ep;
+       u8 endpoint;
+       u8 outinbit;
+       u32 epcfgreg;
+       int flag = (udc->setup.bRequest == USB_REQ_SET_FEATURE ? 1 : 0);
+       int ret;
+
+       switch (udc->setup.bRequestType) {
+       case USB_RECIP_DEVICE:
+               switch (udc->setup.wValue) {
+               case USB_DEVICE_TEST_MODE:
+                       /*
+                        * The Test Mode will be executed
+                        * after the status phase.
+                        */
+                       break;
+               case USB_DEVICE_REMOTE_WAKEUP:
+                       if (flag)
+                               udc->remote_wkp = 1;
+                       else
+                               udc->remote_wkp = 0;
+                       break;
+               default:
+                       xudc_ep0_stall(udc);
+                       break;
+               }
+               break;
+       case USB_RECIP_ENDPOINT:
+               if (!udc->setup.wValue) {
+                       endpoint = udc->setup.wIndex & USB_ENDPOINT_NUMBER_MASK;
+                       target_ep = &udc->ep[endpoint];
+                       outinbit = udc->setup.wIndex & USB_ENDPOINT_DIR_MASK;
+                       outinbit = outinbit >> 7;
+
+                       /* Make sure direction matches.*/
+                       if (outinbit != target_ep->is_in) {
+                               xudc_ep0_stall(udc);
+                               return;
+                       }
+                       epcfgreg = udc->read_fn(udc->addr + target_ep->offset);
+                       if (!endpoint) {
+                               /* Clear the stall.*/
+                               epcfgreg &= ~XUSB_EP_CFG_STALL_MASK;
+                               udc->write_fn(udc->addr,
+                                             target_ep->offset, epcfgreg);
+                       } else {
+                               if (flag) {
+                                       epcfgreg |= XUSB_EP_CFG_STALL_MASK;
+                                       udc->write_fn(udc->addr,
+                                                     target_ep->offset,
+                                                     epcfgreg);
+                               } else {
+                                       /* Unstall the endpoint.*/
+                                       epcfgreg &= ~(XUSB_EP_CFG_STALL_MASK |
+                                               XUSB_EP_CFG_DATA_TOGGLE_MASK);
+                                       udc->write_fn(udc->addr,
+                                                     target_ep->offset,
+                                                     epcfgreg);
+                               }
+                       }
+               }
+               break;
+       default:
+               xudc_ep0_stall(udc);
+               return;
+       }
+
+       req->usb_req.length = 0;
+       ret = __xudc_ep0_queue(ep0, req);
+       if (ret == 0)
+               return;
+
+       dev_err(udc->dev, "Can't respond to SET/CLEAR FEATURE\n");
+       xudc_ep0_stall(udc);
+}
+
+/**
+ * xudc_handle_setup - Processes the setup packet.
+ * @udc: pointer to the usb device controller structure.
+ *
+ * Process setup packet and delegate to gadget layer.
+ */
+static void xudc_handle_setup(struct xusb_udc *udc)
+{
+       struct xusb_ep *ep0 = &udc->ep[0];
+       struct usb_ctrlrequest setup;
+       u32 *ep0rambase;
+
+       /* Load up the chapter 9 command buffer.*/
+       ep0rambase = (u32 __force *) (udc->addr + XUSB_SETUP_PKT_ADDR_OFFSET);
+       memcpy(&setup, ep0rambase, 8);
+
+       udc->setup = setup;
+       udc->setup.wValue = cpu_to_le16(setup.wValue);
+       udc->setup.wIndex = cpu_to_le16(setup.wIndex);
+       udc->setup.wLength = cpu_to_le16(setup.wLength);
+
+       /* Clear previous requests */
+       xudc_nuke(ep0, -ECONNRESET);
+
+       if (udc->setup.bRequestType & USB_DIR_IN) {
+               /* Execute the get command.*/
+               udc->setupseqrx = STATUS_PHASE;
+               udc->setupseqtx = DATA_PHASE;
+       } else {
+               /* Execute the put command.*/
+               udc->setupseqrx = DATA_PHASE;
+               udc->setupseqtx = STATUS_PHASE;
+       }
+
+       switch (udc->setup.bRequest) {
+       case USB_REQ_GET_STATUS:
+               /* Data+Status phase form udc */
+               if ((udc->setup.bRequestType &
+                               (USB_DIR_IN | USB_TYPE_MASK)) !=
+                               (USB_DIR_IN | USB_TYPE_STANDARD))
+                       break;
+               xudc_getstatus(udc);
+               return;
+       case USB_REQ_SET_ADDRESS:
+               /* Status phase from udc */
+               if (udc->setup.bRequestType != (USB_DIR_OUT |
+                               USB_TYPE_STANDARD | USB_RECIP_DEVICE))
+                       break;
+               xudc_setaddress(udc);
+               return;
+       case USB_REQ_CLEAR_FEATURE:
+       case USB_REQ_SET_FEATURE:
+               /* Requests with no data phase, status phase from udc */
+               if ((udc->setup.bRequestType & USB_TYPE_MASK)
+                               != USB_TYPE_STANDARD)
+                       break;
+               xudc_set_clear_feature(udc);
+               return;
+       default:
+               break;
+       }
+
+       spin_unlock(&udc->lock);
+       if (udc->driver->setup(&udc->gadget, &setup) < 0)
+               xudc_ep0_stall(udc);
+       spin_lock(&udc->lock);
+}
+
+/**
+ * xudc_ep0_out - Processes the endpoint 0 OUT token.
+ * @udc: pointer to the usb device controller structure.
+ */
+static void xudc_ep0_out(struct xusb_udc *udc)
+{
+       struct xusb_ep *ep0 = &udc->ep[0];
+       struct xusb_req *req;
+       u8 *ep0rambase;
+       unsigned int bytes_to_rx;
+       void *buffer;
+
+       req = list_first_entry(&ep0->queue, struct xusb_req, queue);
+
+       switch (udc->setupseqrx) {
+       case STATUS_PHASE:
+               /*
+                * This resets both state machines for the next
+                * Setup packet.
+                */
+               udc->setupseqrx = SETUP_PHASE;
+               udc->setupseqtx = SETUP_PHASE;
+               req->usb_req.actual = req->usb_req.length;
+               xudc_done(ep0, req, 0);
+               break;
+       case DATA_PHASE:
+               bytes_to_rx = udc->read_fn(udc->addr +
+                                          XUSB_EP_BUF0COUNT_OFFSET);
+               /* Copy the data to be received from the DPRAM. */
+               ep0rambase = (u8 __force *) (udc->addr +
+                            (ep0->rambase << 2));
+               buffer = req->usb_req.buf + req->usb_req.actual;
+               req->usb_req.actual = req->usb_req.actual + bytes_to_rx;
+               memcpy(buffer, ep0rambase, bytes_to_rx);
+
+               if (req->usb_req.length == req->usb_req.actual) {
+                       /* Data transfer completed get ready for Status stage */
+                       xudc_wrstatus(udc);
+               } else {
+                       /* Enable EP0 buffer to receive data */
+                       udc->write_fn(udc->addr, XUSB_EP_BUF0COUNT_OFFSET, 0);
+                       udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET, 1);
+               }
+               break;
+       default:
+               break;
+       }
+}
+
+/**
+ * xudc_ep0_in - Processes the endpoint 0 IN token.
+ * @udc: pointer to the usb device controller structure.
+ */
+static void xudc_ep0_in(struct xusb_udc *udc)
+{
+       struct xusb_ep *ep0 = &udc->ep[0];
+       struct xusb_req *req;
+       unsigned int bytes_to_tx;
+       void *buffer;
+       u32 epcfgreg;
+       u16 count = 0;
+       u16 length;
+       u8 *ep0rambase;
+       u8 test_mode = udc->setup.wIndex >> 8;
+
+       req = list_first_entry(&ep0->queue, struct xusb_req, queue);
+       bytes_to_tx = req->usb_req.length - req->usb_req.actual;
+
+       switch (udc->setupseqtx) {
+       case STATUS_PHASE:
+               switch (udc->setup.bRequest) {
+               case USB_REQ_SET_ADDRESS:
+                       /* Set the address of the device.*/
+                       udc->write_fn(udc->addr, XUSB_ADDRESS_OFFSET,
+                                     udc->setup.wValue);
+                       break;
+               case USB_REQ_SET_FEATURE:
+                       if (udc->setup.bRequestType ==
+                                       USB_RECIP_DEVICE) {
+                               if (udc->setup.wValue ==
+                                               USB_DEVICE_TEST_MODE)
+                                       udc->write_fn(udc->addr,
+                                                     XUSB_TESTMODE_OFFSET,
+                                                     test_mode);
+                       }
+                       break;
+               }
+               req->usb_req.actual = req->usb_req.length;
+               xudc_done(ep0, req, 0);
+               break;
+       case DATA_PHASE:
+               if (!bytes_to_tx) {
+                       /*
+                        * We're done with data transfer, next
+                        * will be zero length OUT with data toggle of
+                        * 1. Setup data_toggle.
+                        */
+                       epcfgreg = udc->read_fn(udc->addr + ep0->offset);
+                       epcfgreg |= XUSB_EP_CFG_DATA_TOGGLE_MASK;
+                       udc->write_fn(udc->addr, ep0->offset, epcfgreg);
+                       udc->setupseqtx = STATUS_PHASE;
+               } else {
+                       length = count = min_t(u32, bytes_to_tx,
+                                              EP0_MAX_PACKET);
+                       /* Copy the data to be transmitted into the DPRAM. */
+                       ep0rambase = (u8 __force *) (udc->addr +
+                                    (ep0->rambase << 2));
+                       buffer = req->usb_req.buf + req->usb_req.actual;
+                       req->usb_req.actual = req->usb_req.actual + length;
+                       memcpy(ep0rambase, buffer, length);
+               }
+               udc->write_fn(udc->addr, XUSB_EP_BUF0COUNT_OFFSET, count);
+               udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET, 1);
+               break;
+       default:
+               break;
+       }
+}
+
+/**
+ * xudc_ctrl_ep_handler - Endpoint 0 interrupt handler.
+ * @udc: pointer to the udc structure.
+ * @intrstatus:        It's the mask value for the interrupt sources on endpoint 0.
+ *
+ * Processes the commands received during enumeration phase.
+ */
+static void xudc_ctrl_ep_handler(struct xusb_udc *udc, u32 intrstatus)
+{
+
+       if (intrstatus & XUSB_STATUS_SETUP_PACKET_MASK) {
+               xudc_handle_setup(udc);
+       } else {
+               if (intrstatus & XUSB_STATUS_FIFO_BUFF_RDY_MASK)
+                       xudc_ep0_out(udc);
+               else if (intrstatus & XUSB_STATUS_FIFO_BUFF_FREE_MASK)
+                       xudc_ep0_in(udc);
+       }
+}
+
+/**
+ * xudc_nonctrl_ep_handler - Non control endpoint interrupt handler.
+ * @udc: pointer to the udc structure.
+ * @epnum: End point number for which the interrupt is to be processed
+ * @intrstatus:        mask value for interrupt sources of endpoints other
+ *             than endpoint 0.
+ *
+ * Processes the buffer completion interrupts.
+ */
+static void xudc_nonctrl_ep_handler(struct xusb_udc *udc, u8 epnum,
+                                   u32 intrstatus)
+{
+
+       struct xusb_req *req;
+       struct xusb_ep *ep;
+
+       ep = &udc->ep[epnum];
+       /* Process the End point interrupts.*/
+       if (intrstatus & (XUSB_STATUS_EP0_BUFF1_COMP_MASK << epnum))
+               ep->buffer0ready = 0;
+       if (intrstatus & (XUSB_STATUS_EP0_BUFF2_COMP_MASK << epnum))
+               ep->buffer1ready = 0;
+
+       if (list_empty(&ep->queue))
+               return;
+
+       req = list_first_entry(&ep->queue, struct xusb_req, queue);
+
+       if (ep->is_in)
+               xudc_write_fifo(ep, req);
+       else
+               xudc_read_fifo(ep, req);
+}
+
+/**
+ * xudc_irq - The main interrupt handler.
+ * @irq: The interrupt number.
+ * @_udc: pointer to the usb device controller structure.
+ *
+ * Return: IRQ_HANDLED after the interrupt is handled.
+ */
+static irqreturn_t xudc_irq(int irq, void *_udc)
+{
+       struct xusb_udc *udc = _udc;
+       u32 intrstatus;
+       u32 ier;
+       u8 index;
+       u32 bufintr;
+       unsigned long flags;
+
+       spin_lock_irqsave(&udc->lock, flags);
+
+       /*
+        * Event interrupts are level sensitive hence first disable
+        * IER, read ISR and figure out active interrupts.
+        */
+       ier = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
+       ier &= ~XUSB_STATUS_INTR_EVENT_MASK;
+       udc->write_fn(udc->addr, XUSB_IER_OFFSET, ier);
+
+       /* Read the Interrupt Status Register.*/
+       intrstatus = udc->read_fn(udc->addr + XUSB_STATUS_OFFSET);
+
+       /* Call the handler for the event interrupt.*/
+       if (intrstatus & XUSB_STATUS_INTR_EVENT_MASK) {
+               /*
+                * Check if there is any action to be done for :
+                * - USB Reset received {XUSB_STATUS_RESET_MASK}
+                * - USB Suspend received {XUSB_STATUS_SUSPEND_MASK}
+                * - USB Resume received {XUSB_STATUS_RESUME_MASK}
+                * - USB Disconnect received {XUSB_STATUS_DISCONNECT_MASK}
+                */
+               xudc_startup_handler(udc, intrstatus);
+       }
+
+       /* Check the buffer completion interrupts */
+       if (intrstatus & XUSB_STATUS_INTR_BUFF_COMP_ALL_MASK) {
+               /* Enable Reset, Suspend, Resume and Disconnect  */
+               ier = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
+               ier |= XUSB_STATUS_INTR_EVENT_MASK;
+               udc->write_fn(udc->addr, XUSB_IER_OFFSET, ier);
+
+               if (intrstatus & XUSB_STATUS_EP0_BUFF1_COMP_MASK)
+                       xudc_ctrl_ep_handler(udc, intrstatus);
+
+               for (index = 1; index < 8; index++) {
+                       bufintr = ((intrstatus &
+                                 (XUSB_STATUS_EP1_BUFF1_COMP_MASK <<
+                                 (index - 1))) || (intrstatus &
+                                 (XUSB_STATUS_EP1_BUFF2_COMP_MASK <<
+                                 (index - 1))));
+                       if (bufintr) {
+                               xudc_nonctrl_ep_handler(udc, index,
+                                                       intrstatus);
+                       }
+               }
+       }
+
+       spin_unlock_irqrestore(&udc->lock, flags);
+       return IRQ_HANDLED;
+}
+
+/**
+ * xudc_probe - The device probe function for driver initialization.
+ * @pdev: pointer to the platform device structure.
+ *
+ * Return: 0 for success and error value on failure
+ */
+static int xudc_probe(struct platform_device *pdev)
+{
+       struct device_node *np = pdev->dev.of_node;
+       struct resource *res;
+       struct xusb_udc *udc;
+       struct xusb_ep *ep0;
+       int irq;
+       int ret;
+       u32 ier;
+       u8 *buff;
+
+       udc = devm_kzalloc(&pdev->dev, sizeof(*udc), GFP_KERNEL);
+       if (!udc)
+               return -ENOMEM;
+
+       /* Create a dummy request for GET_STATUS, SET_ADDRESS */
+       udc->req = devm_kzalloc(&pdev->dev, sizeof(struct xusb_req),
+                               GFP_KERNEL);
+       if (!udc->req)
+               return -ENOMEM;
+
+       buff = devm_kzalloc(&pdev->dev, STATUSBUFF_SIZE, GFP_KERNEL);
+       if (!buff)
+               return -ENOMEM;
+
+       udc->req->usb_req.buf = buff;
+
+       /* Map the registers */
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       udc->addr = devm_ioremap_resource(&pdev->dev, res);
+       if (!udc->addr)
+               return -ENOMEM;
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0) {
+               dev_err(&pdev->dev, "unable to get irq\n");
+               return irq;
+       }
+       ret = devm_request_irq(&pdev->dev, irq, xudc_irq, 0,
+                              dev_name(&pdev->dev), udc);
+       if (ret < 0) {
+               dev_dbg(&pdev->dev, "unable to request irq %d", irq);
+               goto fail;
+       }
+
+       udc->dma_enabled = of_property_read_bool(np, "xlnx,has-builtin-dma");
+
+       /* Setup gadget structure */
+       udc->gadget.ops = &xusb_udc_ops;
+       udc->gadget.max_speed = USB_SPEED_HIGH;
+       udc->gadget.speed = USB_SPEED_UNKNOWN;
+       udc->gadget.ep0 = &udc->ep[XUSB_EP_NUMBER_ZERO].ep_usb;
+       udc->gadget.name = driver_name;
+
+       spin_lock_init(&udc->lock);
+
+       /* Check for IP endianness */
+       udc->write_fn = xudc_write32_be;
+       udc->read_fn = xudc_read32_be;
+       udc->write_fn(udc->addr, XUSB_TESTMODE_OFFSET, TEST_J);
+       if ((udc->read_fn(udc->addr + XUSB_TESTMODE_OFFSET))
+                       != TEST_J) {
+               udc->write_fn = xudc_write32;
+               udc->read_fn = xudc_read32;
+       }
+       udc->write_fn(udc->addr, XUSB_TESTMODE_OFFSET, 0);
+
+       xudc_eps_init(udc);
+
+       ep0 = &udc->ep[0];
+
+       /* Set device address to 0.*/
+       udc->write_fn(udc->addr, XUSB_ADDRESS_OFFSET, 0);
+
+       ret = usb_add_gadget_udc(&pdev->dev, &udc->gadget);
+       if (ret)
+               goto fail;
+
+       udc->dev = &udc->gadget.dev;
+
+       /* Enable the interrupts.*/
+       ier = XUSB_STATUS_GLOBAL_INTR_MASK | XUSB_STATUS_INTR_EVENT_MASK |
+             XUSB_STATUS_FIFO_BUFF_RDY_MASK | XUSB_STATUS_FIFO_BUFF_FREE_MASK |
+             XUSB_STATUS_SETUP_PACKET_MASK |
+             XUSB_STATUS_INTR_BUFF_COMP_ALL_MASK;
+
+       udc->write_fn(udc->addr, XUSB_IER_OFFSET, ier);
+
+       platform_set_drvdata(pdev, udc);
+
+       dev_vdbg(&pdev->dev, "%s at 0x%08X mapped to 0x%08X %s\n",
+                driver_name, (u32)res->start, (u32 __force)udc->addr,
+                udc->dma_enabled ? "with DMA" : "without DMA");
+
+       return 0;
+fail:
+       dev_err(&pdev->dev, "probe failed, %d\n", ret);
+       return ret;
+}
+
+/**
+ * xudc_remove - Releases the resources allocated during the initialization.
+ * @pdev: pointer to the platform device structure.
+ *
+ * Return: 0 always
+ */
+static int xudc_remove(struct platform_device *pdev)
+{
+       struct xusb_udc *udc = platform_get_drvdata(pdev);
+
+       usb_del_gadget_udc(&udc->gadget);
+
+       return 0;
+}
+
+/* Match table for of_platform binding */
+static const struct of_device_id usb_of_match[] = {
+       { .compatible = "xlnx,usb2-device-4.00.a", },
+       { /* end of list */ },
+};
+MODULE_DEVICE_TABLE(of, usb_of_match);
+
+static struct platform_driver xudc_driver = {
+       .driver = {
+               .name = driver_name,
+               .of_match_table = usb_of_match,
+       },
+       .probe = xudc_probe,
+       .remove = xudc_remove,
+};
+
+module_platform_driver(xudc_driver);
+
+MODULE_DESCRIPTION("Xilinx udc driver");
+MODULE_AUTHOR("Xilinx, Inc");
+MODULE_LICENSE("GPL");