Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / usb / gadget / udc / goku_udc.c
diff --git a/kernel/drivers/usb/gadget/udc/goku_udc.c b/kernel/drivers/usb/gadget/udc/goku_udc.c
new file mode 100644 (file)
index 0000000..9e8d842
--- /dev/null
@@ -0,0 +1,1832 @@
+/*
+ * Toshiba TC86C001 ("Goku-S") USB Device Controller driver
+ *
+ * Copyright (C) 2000-2002 Lineo
+ *      by Stuart Lynne, Tom Rushworth, and Bruce Balden
+ * Copyright (C) 2002 Toshiba Corporation
+ * Copyright (C) 2003 MontaVista Software (source@mvista.com)
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+/*
+ * This device has ep0 and three semi-configurable bulk/interrupt endpoints.
+ *
+ *  - Endpoint numbering is fixed: ep{1,2,3}-bulk
+ *  - Gadget drivers can choose ep maxpacket (8/16/32/64)
+ *  - Gadget drivers can choose direction (IN, OUT)
+ *  - DMA works with ep1 (OUT transfers) and ep2 (IN transfers).
+ */
+
+// #define     VERBOSE         /* extra debug messages (success too) */
+// #define     USB_TRACE       /* packet-level success messages */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/device.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/prefetch.h>
+
+#include <asm/byteorder.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/unaligned.h>
+
+
+#include "goku_udc.h"
+
+#define        DRIVER_DESC             "TC86C001 USB Device Controller"
+#define        DRIVER_VERSION          "30-Oct 2003"
+
+static const char driver_name [] = "goku_udc";
+static const char driver_desc [] = DRIVER_DESC;
+
+MODULE_AUTHOR("source@mvista.com");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+
+/*
+ * IN dma behaves ok under testing, though the IN-dma abort paths don't
+ * seem to behave quite as expected.  Used by default.
+ *
+ * OUT dma documents design problems handling the common "short packet"
+ * transfer termination policy; it couldn't be enabled by default, even
+ * if the OUT-dma abort problems had a resolution.
+ */
+static unsigned use_dma = 1;
+
+#if 0
+//#include <linux/moduleparam.h>
+/* "modprobe goku_udc use_dma=1" etc
+ *     0 to disable dma
+ *     1 to use IN dma only (normal operation)
+ *     2 to use IN and OUT dma
+ */
+module_param(use_dma, uint, S_IRUGO);
+#endif
+
+/*-------------------------------------------------------------------------*/
+
+static void nuke(struct goku_ep *, int status);
+
+static inline void
+command(struct goku_udc_regs __iomem *regs, int command, unsigned epnum)
+{
+       writel(COMMAND_EP(epnum) | command, &regs->Command);
+       udelay(300);
+}
+
+static int
+goku_ep_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
+{
+       struct goku_udc *dev;
+       struct goku_ep  *ep;
+       u32             mode;
+       u16             max;
+       unsigned long   flags;
+
+       ep = container_of(_ep, struct goku_ep, ep);
+       if (!_ep || !desc
+                       || desc->bDescriptorType != USB_DT_ENDPOINT)
+               return -EINVAL;
+       dev = ep->dev;
+       if (ep == &dev->ep[0])
+               return -EINVAL;
+       if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
+               return -ESHUTDOWN;
+       if (ep->num != usb_endpoint_num(desc))
+               return -EINVAL;
+
+       switch (usb_endpoint_type(desc)) {
+       case USB_ENDPOINT_XFER_BULK:
+       case USB_ENDPOINT_XFER_INT:
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       if ((readl(ep->reg_status) & EPxSTATUS_EP_MASK)
+                       != EPxSTATUS_EP_INVALID)
+               return -EBUSY;
+
+       /* enabling the no-toggle interrupt mode would need an api hook */
+       mode = 0;
+       max = get_unaligned_le16(&desc->wMaxPacketSize);
+       switch (max) {
+       case 64:        mode++;
+       case 32:        mode++;
+       case 16:        mode++;
+       case 8:         mode <<= 3;
+                       break;
+       default:
+               return -EINVAL;
+       }
+       mode |= 2 << 1;         /* bulk, or intr-with-toggle */
+
+       /* ep1/ep2 dma direction is chosen early; it works in the other
+        * direction, with pio.  be cautious with out-dma.
+        */
+       ep->is_in = usb_endpoint_dir_in(desc);
+       if (ep->is_in) {
+               mode |= 1;
+               ep->dma = (use_dma != 0) && (ep->num == UDC_MSTRD_ENDPOINT);
+       } else {
+               ep->dma = (use_dma == 2) && (ep->num == UDC_MSTWR_ENDPOINT);
+               if (ep->dma)
+                       DBG(dev, "%s out-dma hides short packets\n",
+                               ep->ep.name);
+       }
+
+       spin_lock_irqsave(&ep->dev->lock, flags);
+
+       /* ep1 and ep2 can do double buffering and/or dma */
+       if (ep->num < 3) {
+               struct goku_udc_regs __iomem    *regs = ep->dev->regs;
+               u32                             tmp;
+
+               /* double buffer except (for now) with pio in */
+               tmp = ((ep->dma || !ep->is_in)
+                               ? 0x10  /* double buffered */
+                               : 0x11  /* single buffer */
+                       ) << ep->num;
+               tmp |= readl(&regs->EPxSingle);
+               writel(tmp, &regs->EPxSingle);
+
+               tmp = (ep->dma ? 0x10/*dma*/ : 0x11/*pio*/) << ep->num;
+               tmp |= readl(&regs->EPxBCS);
+               writel(tmp, &regs->EPxBCS);
+       }
+       writel(mode, ep->reg_mode);
+       command(ep->dev->regs, COMMAND_RESET, ep->num);
+       ep->ep.maxpacket = max;
+       ep->stopped = 0;
+       ep->ep.desc = desc;
+       spin_unlock_irqrestore(&ep->dev->lock, flags);
+
+       DBG(dev, "enable %s %s %s maxpacket %u\n", ep->ep.name,
+               ep->is_in ? "IN" : "OUT",
+               ep->dma ? "dma" : "pio",
+               max);
+
+       return 0;
+}
+
+static void ep_reset(struct goku_udc_regs __iomem *regs, struct goku_ep *ep)
+{
+       struct goku_udc         *dev = ep->dev;
+
+       if (regs) {
+               command(regs, COMMAND_INVALID, ep->num);
+               if (ep->num) {
+                       if (ep->num == UDC_MSTWR_ENDPOINT)
+                               dev->int_enable &= ~(INT_MSTWREND
+                                                       |INT_MSTWRTMOUT);
+                       else if (ep->num == UDC_MSTRD_ENDPOINT)
+                               dev->int_enable &= ~INT_MSTRDEND;
+                       dev->int_enable &= ~INT_EPxDATASET (ep->num);
+               } else
+                       dev->int_enable &= ~INT_EP0;
+               writel(dev->int_enable, &regs->int_enable);
+               readl(&regs->int_enable);
+               if (ep->num < 3) {
+                       struct goku_udc_regs __iomem    *r = ep->dev->regs;
+                       u32                             tmp;
+
+                       tmp = readl(&r->EPxSingle);
+                       tmp &= ~(0x11 << ep->num);
+                       writel(tmp, &r->EPxSingle);
+
+                       tmp = readl(&r->EPxBCS);
+                       tmp &= ~(0x11 << ep->num);
+                       writel(tmp, &r->EPxBCS);
+               }
+               /* reset dma in case we're still using it */
+               if (ep->dma) {
+                       u32     master;
+
+                       master = readl(&regs->dma_master) & MST_RW_BITS;
+                       if (ep->num == UDC_MSTWR_ENDPOINT) {
+                               master &= ~MST_W_BITS;
+                               master |= MST_WR_RESET;
+                       } else {
+                               master &= ~MST_R_BITS;
+                               master |= MST_RD_RESET;
+                       }
+                       writel(master, &regs->dma_master);
+               }
+       }
+
+       usb_ep_set_maxpacket_limit(&ep->ep, MAX_FIFO_SIZE);
+       ep->ep.desc = NULL;
+       ep->stopped = 1;
+       ep->irqs = 0;
+       ep->dma = 0;
+}
+
+static int goku_ep_disable(struct usb_ep *_ep)
+{
+       struct goku_ep  *ep;
+       struct goku_udc *dev;
+       unsigned long   flags;
+
+       ep = container_of(_ep, struct goku_ep, ep);
+       if (!_ep || !ep->ep.desc)
+               return -ENODEV;
+       dev = ep->dev;
+       if (dev->ep0state == EP0_SUSPEND)
+               return -EBUSY;
+
+       VDBG(dev, "disable %s\n", _ep->name);
+
+       spin_lock_irqsave(&dev->lock, flags);
+       nuke(ep, -ESHUTDOWN);
+       ep_reset(dev->regs, ep);
+       spin_unlock_irqrestore(&dev->lock, flags);
+
+       return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static struct usb_request *
+goku_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
+{
+       struct goku_request     *req;
+
+       if (!_ep)
+               return NULL;
+       req = kzalloc(sizeof *req, gfp_flags);
+       if (!req)
+               return NULL;
+
+       INIT_LIST_HEAD(&req->queue);
+       return &req->req;
+}
+
+static void
+goku_free_request(struct usb_ep *_ep, struct usb_request *_req)
+{
+       struct goku_request     *req;
+
+       if (!_ep || !_req)
+               return;
+
+       req = container_of(_req, struct goku_request, req);
+       WARN_ON(!list_empty(&req->queue));
+       kfree(req);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void
+done(struct goku_ep *ep, struct goku_request *req, int status)
+{
+       struct goku_udc         *dev;
+       unsigned                stopped = ep->stopped;
+
+       list_del_init(&req->queue);
+
+       if (likely(req->req.status == -EINPROGRESS))
+               req->req.status = status;
+       else
+               status = req->req.status;
+
+       dev = ep->dev;
+
+       if (ep->dma)
+               usb_gadget_unmap_request(&dev->gadget, &req->req, ep->is_in);
+
+#ifndef USB_TRACE
+       if (status && status != -ESHUTDOWN)
+#endif
+               VDBG(dev, "complete %s req %p stat %d len %u/%u\n",
+                       ep->ep.name, &req->req, status,
+                       req->req.actual, req->req.length);
+
+       /* don't modify queue heads during completion callback */
+       ep->stopped = 1;
+       spin_unlock(&dev->lock);
+       usb_gadget_giveback_request(&ep->ep, &req->req);
+       spin_lock(&dev->lock);
+       ep->stopped = stopped;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static inline int
+write_packet(u32 __iomem *fifo, u8 *buf, struct goku_request *req, unsigned max)
+{
+       unsigned        length, count;
+
+       length = min(req->req.length - req->req.actual, max);
+       req->req.actual += length;
+
+       count = length;
+       while (likely(count--))
+               writel(*buf++, fifo);
+       return length;
+}
+
+// return:  0 = still running, 1 = completed, negative = errno
+static int write_fifo(struct goku_ep *ep, struct goku_request *req)
+{
+       struct goku_udc *dev = ep->dev;
+       u32             tmp;
+       u8              *buf;
+       unsigned        count;
+       int             is_last;
+
+       tmp = readl(&dev->regs->DataSet);
+       buf = req->req.buf + req->req.actual;
+       prefetch(buf);
+
+       dev = ep->dev;
+       if (unlikely(ep->num == 0 && dev->ep0state != EP0_IN))
+               return -EL2HLT;
+
+       /* NOTE:  just single-buffered PIO-IN for now.  */
+       if (unlikely((tmp & DATASET_A(ep->num)) != 0))
+               return 0;
+
+       /* clear our "packet available" irq */
+       if (ep->num != 0)
+               writel(~INT_EPxDATASET(ep->num), &dev->regs->int_status);
+
+       count = write_packet(ep->reg_fifo, buf, req, ep->ep.maxpacket);
+
+       /* last packet often short (sometimes a zlp, especially on ep0) */
+       if (unlikely(count != ep->ep.maxpacket)) {
+               writel(~(1<<ep->num), &dev->regs->EOP);
+               if (ep->num == 0) {
+                       dev->ep[0].stopped = 1;
+                       dev->ep0state = EP0_STATUS;
+               }
+               is_last = 1;
+       } else {
+               if (likely(req->req.length != req->req.actual)
+                               || req->req.zero)
+                       is_last = 0;
+               else
+                       is_last = 1;
+       }
+#if 0          /* printk seemed to trash is_last...*/
+//#ifdef USB_TRACE
+       VDBG(dev, "wrote %s %u bytes%s IN %u left %p\n",
+               ep->ep.name, count, is_last ? "/last" : "",
+               req->req.length - req->req.actual, req);
+#endif
+
+       /* requests complete when all IN data is in the FIFO,
+        * or sometimes later, if a zlp was needed.
+        */
+       if (is_last) {
+               done(ep, req, 0);
+               return 1;
+       }
+
+       return 0;
+}
+
+static int read_fifo(struct goku_ep *ep, struct goku_request *req)
+{
+       struct goku_udc_regs __iomem    *regs;
+       u32                             size, set;
+       u8                              *buf;
+       unsigned                        bufferspace, is_short, dbuff;
+
+       regs = ep->dev->regs;
+top:
+       buf = req->req.buf + req->req.actual;
+       prefetchw(buf);
+
+       if (unlikely(ep->num == 0 && ep->dev->ep0state != EP0_OUT))
+               return -EL2HLT;
+
+       dbuff = (ep->num == 1 || ep->num == 2);
+       do {
+               /* ack dataset irq matching the status we'll handle */
+               if (ep->num != 0)
+                       writel(~INT_EPxDATASET(ep->num), &regs->int_status);
+
+               set = readl(&regs->DataSet) & DATASET_AB(ep->num);
+               size = readl(&regs->EPxSizeLA[ep->num]);
+               bufferspace = req->req.length - req->req.actual;
+
+               /* usually do nothing without an OUT packet */
+               if (likely(ep->num != 0 || bufferspace != 0)) {
+                       if (unlikely(set == 0))
+                               break;
+                       /* use ep1/ep2 double-buffering for OUT */
+                       if (!(size & PACKET_ACTIVE))
+                               size = readl(&regs->EPxSizeLB[ep->num]);
+                       if (!(size & PACKET_ACTIVE))    /* "can't happen" */
+                               break;
+                       size &= DATASIZE;       /* EPxSizeH == 0 */
+
+               /* ep0out no-out-data case for set_config, etc */
+               } else
+                       size = 0;
+
+               /* read all bytes from this packet */
+               req->req.actual += size;
+               is_short = (size < ep->ep.maxpacket);
+#ifdef USB_TRACE
+               VDBG(ep->dev, "read %s %u bytes%s OUT req %p %u/%u\n",
+                       ep->ep.name, size, is_short ? "/S" : "",
+                       req, req->req.actual, req->req.length);
+#endif
+               while (likely(size-- != 0)) {
+                       u8      byte = (u8) readl(ep->reg_fifo);
+
+                       if (unlikely(bufferspace == 0)) {
+                               /* this happens when the driver's buffer
+                                * is smaller than what the host sent.
+                                * discard the extra data in this packet.
+                                */
+                               if (req->req.status != -EOVERFLOW)
+                                       DBG(ep->dev, "%s overflow %u\n",
+                                               ep->ep.name, size);
+                               req->req.status = -EOVERFLOW;
+                       } else {
+                               *buf++ = byte;
+                               bufferspace--;
+                       }
+               }
+
+               /* completion */
+               if (unlikely(is_short || req->req.actual == req->req.length)) {
+                       if (unlikely(ep->num == 0)) {
+                               /* non-control endpoints now usable? */
+                               if (ep->dev->req_config)
+                                       writel(ep->dev->configured
+                                                       ? USBSTATE_CONFIGURED
+                                                       : 0,
+                                               &regs->UsbState);
+                               /* ep0out status stage */
+                               writel(~(1<<0), &regs->EOP);
+                               ep->stopped = 1;
+                               ep->dev->ep0state = EP0_STATUS;
+                       }
+                       done(ep, req, 0);
+
+                       /* empty the second buffer asap */
+                       if (dbuff && !list_empty(&ep->queue)) {
+                               req = list_entry(ep->queue.next,
+                                               struct goku_request, queue);
+                               goto top;
+                       }
+                       return 1;
+               }
+       } while (dbuff);
+       return 0;
+}
+
+static inline void
+pio_irq_enable(struct goku_udc *dev,
+               struct goku_udc_regs __iomem *regs, int epnum)
+{
+       dev->int_enable |= INT_EPxDATASET (epnum);
+       writel(dev->int_enable, &regs->int_enable);
+       /* write may still be posted */
+}
+
+static inline void
+pio_irq_disable(struct goku_udc *dev,
+               struct goku_udc_regs __iomem *regs, int epnum)
+{
+       dev->int_enable &= ~INT_EPxDATASET (epnum);
+       writel(dev->int_enable, &regs->int_enable);
+       /* write may still be posted */
+}
+
+static inline void
+pio_advance(struct goku_ep *ep)
+{
+       struct goku_request     *req;
+
+       if (unlikely(list_empty (&ep->queue)))
+               return;
+       req = list_entry(ep->queue.next, struct goku_request, queue);
+       (ep->is_in ? write_fifo : read_fifo)(ep, req);
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+// return:  0 = q running, 1 = q stopped, negative = errno
+static int start_dma(struct goku_ep *ep, struct goku_request *req)
+{
+       struct goku_udc_regs __iomem    *regs = ep->dev->regs;
+       u32                             master;
+       u32                             start = req->req.dma;
+       u32                             end = start + req->req.length - 1;
+
+       master = readl(&regs->dma_master) & MST_RW_BITS;
+
+       /* re-init the bits affecting IN dma; careful with zlps */
+       if (likely(ep->is_in)) {
+               if (unlikely(master & MST_RD_ENA)) {
+                       DBG (ep->dev, "start, IN active dma %03x!!\n",
+                               master);
+//                     return -EL2HLT;
+               }
+               writel(end, &regs->in_dma_end);
+               writel(start, &regs->in_dma_start);
+
+               master &= ~MST_R_BITS;
+               if (unlikely(req->req.length == 0))
+                       master = MST_RD_ENA | MST_RD_EOPB;
+               else if ((req->req.length % ep->ep.maxpacket) != 0
+                                       || req->req.zero)
+                       master = MST_RD_ENA | MST_EOPB_ENA;
+               else
+                       master = MST_RD_ENA | MST_EOPB_DIS;
+
+               ep->dev->int_enable |= INT_MSTRDEND;
+
+       /* Goku DMA-OUT merges short packets, which plays poorly with
+        * protocols where short packets mark the transfer boundaries.
+        * The chip supports a nonstandard policy with INT_MSTWRTMOUT,
+        * ending transfers after 3 SOFs; we don't turn it on.
+        */
+       } else {
+               if (unlikely(master & MST_WR_ENA)) {
+                       DBG (ep->dev, "start, OUT active dma %03x!!\n",
+                               master);
+//                     return -EL2HLT;
+               }
+               writel(end, &regs->out_dma_end);
+               writel(start, &regs->out_dma_start);
+
+               master &= ~MST_W_BITS;
+               master |= MST_WR_ENA | MST_TIMEOUT_DIS;
+
+               ep->dev->int_enable |= INT_MSTWREND|INT_MSTWRTMOUT;
+       }
+
+       writel(master, &regs->dma_master);
+       writel(ep->dev->int_enable, &regs->int_enable);
+       return 0;
+}
+
+static void dma_advance(struct goku_udc *dev, struct goku_ep *ep)
+{
+       struct goku_request             *req;
+       struct goku_udc_regs __iomem    *regs = ep->dev->regs;
+       u32                             master;
+
+       master = readl(&regs->dma_master);
+
+       if (unlikely(list_empty(&ep->queue))) {
+stop:
+               if (ep->is_in)
+                       dev->int_enable &= ~INT_MSTRDEND;
+               else
+                       dev->int_enable &= ~(INT_MSTWREND|INT_MSTWRTMOUT);
+               writel(dev->int_enable, &regs->int_enable);
+               return;
+       }
+       req = list_entry(ep->queue.next, struct goku_request, queue);
+
+       /* normal hw dma completion (not abort) */
+       if (likely(ep->is_in)) {
+               if (unlikely(master & MST_RD_ENA))
+                       return;
+               req->req.actual = readl(&regs->in_dma_current);
+       } else {
+               if (unlikely(master & MST_WR_ENA))
+                       return;
+
+               /* hardware merges short packets, and also hides packet
+                * overruns.  a partial packet MAY be in the fifo here.
+                */
+               req->req.actual = readl(&regs->out_dma_current);
+       }
+       req->req.actual -= req->req.dma;
+       req->req.actual++;
+
+#ifdef USB_TRACE
+       VDBG(dev, "done %s %s dma, %u/%u bytes, req %p\n",
+               ep->ep.name, ep->is_in ? "IN" : "OUT",
+               req->req.actual, req->req.length, req);
+#endif
+       done(ep, req, 0);
+       if (list_empty(&ep->queue))
+               goto stop;
+       req = list_entry(ep->queue.next, struct goku_request, queue);
+       (void) start_dma(ep, req);
+}
+
+static void abort_dma(struct goku_ep *ep, int status)
+{
+       struct goku_udc_regs __iomem    *regs = ep->dev->regs;
+       struct goku_request             *req;
+       u32                             curr, master;
+
+       /* NAK future host requests, hoping the implicit delay lets the
+        * dma engine finish reading (or writing) its latest packet and
+        * empty the dma buffer (up to 16 bytes).
+        *
+        * This avoids needing to clean up a partial packet in the fifo;
+        * we can't do that for IN without side effects to HALT and TOGGLE.
+        */
+       command(regs, COMMAND_FIFO_DISABLE, ep->num);
+       req = list_entry(ep->queue.next, struct goku_request, queue);
+       master = readl(&regs->dma_master) & MST_RW_BITS;
+
+       /* FIXME using these resets isn't usably documented. this may
+        * not work unless it's followed by disabling the endpoint.
+        *
+        * FIXME the OUT reset path doesn't even behave consistently.
+        */
+       if (ep->is_in) {
+               if (unlikely((readl(&regs->dma_master) & MST_RD_ENA) == 0))
+                       goto finished;
+               curr = readl(&regs->in_dma_current);
+
+               writel(curr, &regs->in_dma_end);
+               writel(curr, &regs->in_dma_start);
+
+               master &= ~MST_R_BITS;
+               master |= MST_RD_RESET;
+               writel(master, &regs->dma_master);
+
+               if (readl(&regs->dma_master) & MST_RD_ENA)
+                       DBG(ep->dev, "IN dma active after reset!\n");
+
+       } else {
+               if (unlikely((readl(&regs->dma_master) & MST_WR_ENA) == 0))
+                       goto finished;
+               curr = readl(&regs->out_dma_current);
+
+               writel(curr, &regs->out_dma_end);
+               writel(curr, &regs->out_dma_start);
+
+               master &= ~MST_W_BITS;
+               master |= MST_WR_RESET;
+               writel(master, &regs->dma_master);
+
+               if (readl(&regs->dma_master) & MST_WR_ENA)
+                       DBG(ep->dev, "OUT dma active after reset!\n");
+       }
+       req->req.actual = (curr - req->req.dma) + 1;
+       req->req.status = status;
+
+       VDBG(ep->dev, "%s %s %s %d/%d\n", __func__, ep->ep.name,
+               ep->is_in ? "IN" : "OUT",
+               req->req.actual, req->req.length);
+
+       command(regs, COMMAND_FIFO_ENABLE, ep->num);
+
+       return;
+
+finished:
+       /* dma already completed; no abort needed */
+       command(regs, COMMAND_FIFO_ENABLE, ep->num);
+       req->req.actual = req->req.length;
+       req->req.status = 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int
+goku_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
+{
+       struct goku_request     *req;
+       struct goku_ep          *ep;
+       struct goku_udc         *dev;
+       unsigned long           flags;
+       int                     status;
+
+       /* always require a cpu-view buffer so pio works */
+       req = container_of(_req, struct goku_request, req);
+       if (unlikely(!_req || !_req->complete
+                       || !_req->buf || !list_empty(&req->queue)))
+               return -EINVAL;
+       ep = container_of(_ep, struct goku_ep, ep);
+       if (unlikely(!_ep || (!ep->ep.desc && ep->num != 0)))
+               return -EINVAL;
+       dev = ep->dev;
+       if (unlikely(!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN))
+               return -ESHUTDOWN;
+
+       /* can't touch registers when suspended */
+       if (dev->ep0state == EP0_SUSPEND)
+               return -EBUSY;
+
+       /* set up dma mapping in case the caller didn't */
+       if (ep->dma) {
+               status = usb_gadget_map_request(&dev->gadget, &req->req,
+                               ep->is_in);
+               if (status)
+                       return status;
+       }
+
+#ifdef USB_TRACE
+       VDBG(dev, "%s queue req %p, len %u buf %p\n",
+                       _ep->name, _req, _req->length, _req->buf);
+#endif
+
+       spin_lock_irqsave(&dev->lock, flags);
+
+       _req->status = -EINPROGRESS;
+       _req->actual = 0;
+
+       /* for ep0 IN without premature status, zlp is required and
+        * writing EOP starts the status stage (OUT).
+        */
+       if (unlikely(ep->num == 0 && ep->is_in))
+               _req->zero = 1;
+
+       /* kickstart this i/o queue? */
+       status = 0;
+       if (list_empty(&ep->queue) && likely(!ep->stopped)) {
+               /* dma:  done after dma completion IRQ (or error)
+                * pio:  done after last fifo operation
+                */
+               if (ep->dma)
+                       status = start_dma(ep, req);
+               else
+                       status = (ep->is_in ? write_fifo : read_fifo)(ep, req);
+
+               if (unlikely(status != 0)) {
+                       if (status > 0)
+                               status = 0;
+                       req = NULL;
+               }
+
+       } /* else pio or dma irq handler advances the queue. */
+
+       if (likely(req != NULL))
+               list_add_tail(&req->queue, &ep->queue);
+
+       if (likely(!list_empty(&ep->queue))
+                       && likely(ep->num != 0)
+                       && !ep->dma
+                       && !(dev->int_enable & INT_EPxDATASET (ep->num)))
+               pio_irq_enable(dev, dev->regs, ep->num);
+
+       spin_unlock_irqrestore(&dev->lock, flags);
+
+       /* pci writes may still be posted */
+       return status;
+}
+
+/* dequeue ALL requests */
+static void nuke(struct goku_ep *ep, int status)
+{
+       struct goku_request     *req;
+
+       ep->stopped = 1;
+       if (list_empty(&ep->queue))
+               return;
+       if (ep->dma)
+               abort_dma(ep, status);
+       while (!list_empty(&ep->queue)) {
+               req = list_entry(ep->queue.next, struct goku_request, queue);
+               done(ep, req, status);
+       }
+}
+
+/* dequeue JUST ONE request */
+static int goku_dequeue(struct usb_ep *_ep, struct usb_request *_req)
+{
+       struct goku_request     *req;
+       struct goku_ep          *ep;
+       struct goku_udc         *dev;
+       unsigned long           flags;
+
+       ep = container_of(_ep, struct goku_ep, ep);
+       if (!_ep || !_req || (!ep->ep.desc && ep->num != 0))
+               return -EINVAL;
+       dev = ep->dev;
+       if (!dev->driver)
+               return -ESHUTDOWN;
+
+       /* we can't touch (dma) registers when suspended */
+       if (dev->ep0state == EP0_SUSPEND)
+               return -EBUSY;
+
+       VDBG(dev, "%s %s %s %s %p\n", __func__, _ep->name,
+               ep->is_in ? "IN" : "OUT",
+               ep->dma ? "dma" : "pio",
+               _req);
+
+       spin_lock_irqsave(&dev->lock, flags);
+
+       /* make sure it's actually queued on this endpoint */
+       list_for_each_entry (req, &ep->queue, queue) {
+               if (&req->req == _req)
+                       break;
+       }
+       if (&req->req != _req) {
+               spin_unlock_irqrestore (&dev->lock, flags);
+               return -EINVAL;
+       }
+
+       if (ep->dma && ep->queue.next == &req->queue && !ep->stopped) {
+               abort_dma(ep, -ECONNRESET);
+               done(ep, req, -ECONNRESET);
+               dma_advance(dev, ep);
+       } else if (!list_empty(&req->queue))
+               done(ep, req, -ECONNRESET);
+       else
+               req = NULL;
+       spin_unlock_irqrestore(&dev->lock, flags);
+
+       return req ? 0 : -EOPNOTSUPP;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void goku_clear_halt(struct goku_ep *ep)
+{
+       // assert (ep->num !=0)
+       VDBG(ep->dev, "%s clear halt\n", ep->ep.name);
+       command(ep->dev->regs, COMMAND_SETDATA0, ep->num);
+       command(ep->dev->regs, COMMAND_STALL_CLEAR, ep->num);
+       if (ep->stopped) {
+               ep->stopped = 0;
+               if (ep->dma) {
+                       struct goku_request     *req;
+
+                       if (list_empty(&ep->queue))
+                               return;
+                       req = list_entry(ep->queue.next, struct goku_request,
+                                               queue);
+                       (void) start_dma(ep, req);
+               } else
+                       pio_advance(ep);
+       }
+}
+
+static int goku_set_halt(struct usb_ep *_ep, int value)
+{
+       struct goku_ep  *ep;
+       unsigned long   flags;
+       int             retval = 0;
+
+       if (!_ep)
+               return -ENODEV;
+       ep = container_of (_ep, struct goku_ep, ep);
+
+       if (ep->num == 0) {
+               if (value) {
+                       ep->dev->ep0state = EP0_STALL;
+                       ep->dev->ep[0].stopped = 1;
+               } else
+                       return -EINVAL;
+
+       /* don't change EPxSTATUS_EP_INVALID to READY */
+       } else if (!ep->ep.desc) {
+               DBG(ep->dev, "%s %s inactive?\n", __func__, ep->ep.name);
+               return -EINVAL;
+       }
+
+       spin_lock_irqsave(&ep->dev->lock, flags);
+       if (!list_empty(&ep->queue))
+               retval = -EAGAIN;
+       else if (ep->is_in && value
+                       /* data in (either) packet buffer? */
+                       && (readl(&ep->dev->regs->DataSet)
+                                       & DATASET_AB(ep->num)))
+               retval = -EAGAIN;
+       else if (!value)
+               goku_clear_halt(ep);
+       else {
+               ep->stopped = 1;
+               VDBG(ep->dev, "%s set halt\n", ep->ep.name);
+               command(ep->dev->regs, COMMAND_STALL, ep->num);
+               readl(ep->reg_status);
+       }
+       spin_unlock_irqrestore(&ep->dev->lock, flags);
+       return retval;
+}
+
+static int goku_fifo_status(struct usb_ep *_ep)
+{
+       struct goku_ep                  *ep;
+       struct goku_udc_regs __iomem    *regs;
+       u32                             size;
+
+       if (!_ep)
+               return -ENODEV;
+       ep = container_of(_ep, struct goku_ep, ep);
+
+       /* size is only reported sanely for OUT */
+       if (ep->is_in)
+               return -EOPNOTSUPP;
+
+       /* ignores 16-byte dma buffer; SizeH == 0 */
+       regs = ep->dev->regs;
+       size = readl(&regs->EPxSizeLA[ep->num]) & DATASIZE;
+       size += readl(&regs->EPxSizeLB[ep->num]) & DATASIZE;
+       VDBG(ep->dev, "%s %s %u\n", __func__, ep->ep.name, size);
+       return size;
+}
+
+static void goku_fifo_flush(struct usb_ep *_ep)
+{
+       struct goku_ep                  *ep;
+       struct goku_udc_regs __iomem    *regs;
+       u32                             size;
+
+       if (!_ep)
+               return;
+       ep = container_of(_ep, struct goku_ep, ep);
+       VDBG(ep->dev, "%s %s\n", __func__, ep->ep.name);
+
+       /* don't change EPxSTATUS_EP_INVALID to READY */
+       if (!ep->ep.desc && ep->num != 0) {
+               DBG(ep->dev, "%s %s inactive?\n", __func__, ep->ep.name);
+               return;
+       }
+
+       regs = ep->dev->regs;
+       size = readl(&regs->EPxSizeLA[ep->num]);
+       size &= DATASIZE;
+
+       /* Non-desirable behavior:  FIFO_CLEAR also clears the
+        * endpoint halt feature.  For OUT, we _could_ just read
+        * the bytes out (PIO, if !ep->dma); for in, no choice.
+        */
+       if (size)
+               command(regs, COMMAND_FIFO_CLEAR, ep->num);
+}
+
+static struct usb_ep_ops goku_ep_ops = {
+       .enable         = goku_ep_enable,
+       .disable        = goku_ep_disable,
+
+       .alloc_request  = goku_alloc_request,
+       .free_request   = goku_free_request,
+
+       .queue          = goku_queue,
+       .dequeue        = goku_dequeue,
+
+       .set_halt       = goku_set_halt,
+       .fifo_status    = goku_fifo_status,
+       .fifo_flush     = goku_fifo_flush,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int goku_get_frame(struct usb_gadget *_gadget)
+{
+       return -EOPNOTSUPP;
+}
+
+static int goku_udc_start(struct usb_gadget *g,
+               struct usb_gadget_driver *driver);
+static int goku_udc_stop(struct usb_gadget *g);
+
+static const struct usb_gadget_ops goku_ops = {
+       .get_frame      = goku_get_frame,
+       .udc_start      = goku_udc_start,
+       .udc_stop       = goku_udc_stop,
+       // no remote wakeup
+       // not selfpowered
+};
+
+/*-------------------------------------------------------------------------*/
+
+static inline const char *dmastr(void)
+{
+       if (use_dma == 0)
+               return "(dma disabled)";
+       else if (use_dma == 2)
+               return "(dma IN and OUT)";
+       else
+               return "(dma IN)";
+}
+
+#ifdef CONFIG_USB_GADGET_DEBUG_FILES
+
+static const char proc_node_name [] = "driver/udc";
+
+#define FOURBITS "%s%s%s%s"
+#define EIGHTBITS FOURBITS FOURBITS
+
+static void dump_intmask(struct seq_file *m, const char *label, u32 mask)
+{
+       /* int_status is the same format ... */
+       seq_printf(m, "%s %05X =" FOURBITS EIGHTBITS EIGHTBITS "\n",
+                  label, mask,
+                  (mask & INT_PWRDETECT) ? " power" : "",
+                  (mask & INT_SYSERROR) ? " sys" : "",
+                  (mask & INT_MSTRDEND) ? " in-dma" : "",
+                  (mask & INT_MSTWRTMOUT) ? " wrtmo" : "",
+
+                  (mask & INT_MSTWREND) ? " out-dma" : "",
+                  (mask & INT_MSTWRSET) ? " wrset" : "",
+                  (mask & INT_ERR) ? " err" : "",
+                  (mask & INT_SOF) ? " sof" : "",
+
+                  (mask & INT_EP3NAK) ? " ep3nak" : "",
+                  (mask & INT_EP2NAK) ? " ep2nak" : "",
+                  (mask & INT_EP1NAK) ? " ep1nak" : "",
+                  (mask & INT_EP3DATASET) ? " ep3" : "",
+
+                  (mask & INT_EP2DATASET) ? " ep2" : "",
+                  (mask & INT_EP1DATASET) ? " ep1" : "",
+                  (mask & INT_STATUSNAK) ? " ep0snak" : "",
+                  (mask & INT_STATUS) ? " ep0status" : "",
+
+                  (mask & INT_SETUP) ? " setup" : "",
+                  (mask & INT_ENDPOINT0) ? " ep0" : "",
+                  (mask & INT_USBRESET) ? " reset" : "",
+                  (mask & INT_SUSPEND) ? " suspend" : "");
+}
+
+static const char *udc_ep_state(enum ep0state state)
+{
+       switch (state) {
+       case EP0_DISCONNECT:
+               return "ep0_disconnect";
+       case EP0_IDLE:
+               return "ep0_idle";
+       case EP0_IN:
+               return "ep0_in";
+       case EP0_OUT:
+               return "ep0_out";
+       case EP0_STATUS:
+               return "ep0_status";
+       case EP0_STALL:
+               return "ep0_stall";
+       case EP0_SUSPEND:
+               return "ep0_suspend";
+       }
+
+       return "ep0_?";
+}
+
+static const char *udc_ep_status(u32 status)
+{
+       switch (status & EPxSTATUS_EP_MASK) {
+       case EPxSTATUS_EP_READY:
+               return "ready";
+       case EPxSTATUS_EP_DATAIN:
+               return "packet";
+       case EPxSTATUS_EP_FULL:
+               return "full";
+       case EPxSTATUS_EP_TX_ERR:       /* host will retry */
+               return "tx_err";
+       case EPxSTATUS_EP_RX_ERR:
+               return "rx_err";
+       case EPxSTATUS_EP_BUSY:         /* ep0 only */
+               return "busy";
+       case EPxSTATUS_EP_STALL:
+               return "stall";
+       case EPxSTATUS_EP_INVALID:      /* these "can't happen" */
+               return "invalid";
+       }
+
+       return "?";
+}
+
+static int udc_proc_read(struct seq_file *m, void *v)
+{
+       struct goku_udc                 *dev = m->private;
+       struct goku_udc_regs __iomem    *regs = dev->regs;
+       unsigned long                   flags;
+       int                             i, is_usb_connected;
+       u32                             tmp;
+
+       local_irq_save(flags);
+
+       /* basic device status */
+       tmp = readl(&regs->power_detect);
+       is_usb_connected = tmp & PW_DETECT;
+       seq_printf(m,
+                  "%s - %s\n"
+                  "%s version: %s %s\n"
+                  "Gadget driver: %s\n"
+                  "Host %s, %s\n"
+                  "\n",
+                  pci_name(dev->pdev), driver_desc,
+                  driver_name, DRIVER_VERSION, dmastr(),
+                  dev->driver ? dev->driver->driver.name : "(none)",
+                  is_usb_connected
+                          ? ((tmp & PW_PULLUP) ? "full speed" : "powered")
+                          : "disconnected",
+                  udc_ep_state(dev->ep0state));
+
+       dump_intmask(m, "int_status", readl(&regs->int_status));
+       dump_intmask(m, "int_enable", readl(&regs->int_enable));
+
+       if (!is_usb_connected || !dev->driver || (tmp & PW_PULLUP) == 0)
+               goto done;
+
+       /* registers for (active) device and ep0 */
+       seq_printf(m, "\nirqs %lu\ndataset %02x single.bcs %02x.%02x state %x addr %u\n",
+                  dev->irqs, readl(&regs->DataSet),
+                  readl(&regs->EPxSingle), readl(&regs->EPxBCS),
+                  readl(&regs->UsbState),
+                  readl(&regs->address));
+       if (seq_has_overflowed(m))
+               goto done;
+
+       tmp = readl(&regs->dma_master);
+       seq_printf(m, "dma %03X =" EIGHTBITS "%s %s\n",
+                  tmp,
+                  (tmp & MST_EOPB_DIS) ? " eopb-" : "",
+                  (tmp & MST_EOPB_ENA) ? " eopb+" : "",
+                  (tmp & MST_TIMEOUT_DIS) ? " tmo-" : "",
+                  (tmp & MST_TIMEOUT_ENA) ? " tmo+" : "",
+
+                  (tmp & MST_RD_EOPB) ? " eopb" : "",
+                  (tmp & MST_RD_RESET) ? " in_reset" : "",
+                  (tmp & MST_WR_RESET) ? " out_reset" : "",
+                  (tmp & MST_RD_ENA) ? " IN" : "",
+
+                  (tmp & MST_WR_ENA) ? " OUT" : "",
+                  (tmp & MST_CONNECTION) ? "ep1in/ep2out" : "ep1out/ep2in");
+       if (seq_has_overflowed(m))
+               goto done;
+
+       /* dump endpoint queues */
+       for (i = 0; i < 4; i++) {
+               struct goku_ep          *ep = &dev->ep [i];
+               struct goku_request     *req;
+
+               if (i && !ep->ep.desc)
+                       continue;
+
+               tmp = readl(ep->reg_status);
+               seq_printf(m, "%s %s max %u %s, irqs %lu, status %02x (%s) " FOURBITS "\n",
+                          ep->ep.name,
+                          ep->is_in ? "in" : "out",
+                          ep->ep.maxpacket,
+                          ep->dma ? "dma" : "pio",
+                          ep->irqs,
+                          tmp, udc_ep_status(tmp),
+                          (tmp & EPxSTATUS_TOGGLE) ? "data1" : "data0",
+                          (tmp & EPxSTATUS_SUSPEND) ? " suspend" : "",
+                          (tmp & EPxSTATUS_FIFO_DISABLE) ? " disable" : "",
+                          (tmp & EPxSTATUS_STAGE_ERROR) ? " ep0stat" : "");
+               if (seq_has_overflowed(m))
+                       goto done;
+
+               if (list_empty(&ep->queue)) {
+                       seq_puts(m, "\t(nothing queued)\n");
+                       if (seq_has_overflowed(m))
+                               goto done;
+                       continue;
+               }
+               list_for_each_entry(req, &ep->queue, queue) {
+                       if (ep->dma && req->queue.prev == &ep->queue) {
+                               if (i == UDC_MSTRD_ENDPOINT)
+                                       tmp = readl(&regs->in_dma_current);
+                               else
+                                       tmp = readl(&regs->out_dma_current);
+                               tmp -= req->req.dma;
+                               tmp++;
+                       } else
+                               tmp = req->req.actual;
+
+                       seq_printf(m, "\treq %p len %u/%u buf %p\n",
+                                  &req->req, tmp, req->req.length,
+                                  req->req.buf);
+                       if (seq_has_overflowed(m))
+                               goto done;
+               }
+       }
+
+done:
+       local_irq_restore(flags);
+       return 0;
+}
+
+/*
+ * seq_file wrappers for procfile show routines.
+ */
+static int udc_proc_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, udc_proc_read, PDE_DATA(file_inode(file)));
+}
+
+static const struct file_operations udc_proc_fops = {
+       .open           = udc_proc_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+
+#endif /* CONFIG_USB_GADGET_DEBUG_FILES */
+
+/*-------------------------------------------------------------------------*/
+
+static void udc_reinit (struct goku_udc *dev)
+{
+       static char *names [] = { "ep0", "ep1-bulk", "ep2-bulk", "ep3-bulk" };
+
+       unsigned i;
+
+       INIT_LIST_HEAD (&dev->gadget.ep_list);
+       dev->gadget.ep0 = &dev->ep [0].ep;
+       dev->gadget.speed = USB_SPEED_UNKNOWN;
+       dev->ep0state = EP0_DISCONNECT;
+       dev->irqs = 0;
+
+       for (i = 0; i < 4; i++) {
+               struct goku_ep  *ep = &dev->ep[i];
+
+               ep->num = i;
+               ep->ep.name = names[i];
+               ep->reg_fifo = &dev->regs->ep_fifo [i];
+               ep->reg_status = &dev->regs->ep_status [i];
+               ep->reg_mode = &dev->regs->ep_mode[i];
+
+               ep->ep.ops = &goku_ep_ops;
+               list_add_tail (&ep->ep.ep_list, &dev->gadget.ep_list);
+               ep->dev = dev;
+               INIT_LIST_HEAD (&ep->queue);
+
+               ep_reset(NULL, ep);
+       }
+
+       dev->ep[0].reg_mode = NULL;
+       usb_ep_set_maxpacket_limit(&dev->ep[0].ep, MAX_EP0_SIZE);
+       list_del_init (&dev->ep[0].ep.ep_list);
+}
+
+static void udc_reset(struct goku_udc *dev)
+{
+       struct goku_udc_regs __iomem    *regs = dev->regs;
+
+       writel(0, &regs->power_detect);
+       writel(0, &regs->int_enable);
+       readl(&regs->int_enable);
+       dev->int_enable = 0;
+
+       /* deassert reset, leave USB D+ at hi-Z (no pullup)
+        * don't let INT_PWRDETECT sequence begin
+        */
+       udelay(250);
+       writel(PW_RESETB, &regs->power_detect);
+       readl(&regs->int_enable);
+}
+
+static void ep0_start(struct goku_udc *dev)
+{
+       struct goku_udc_regs __iomem    *regs = dev->regs;
+       unsigned                        i;
+
+       VDBG(dev, "%s\n", __func__);
+
+       udc_reset(dev);
+       udc_reinit (dev);
+       //writel(MST_EOPB_ENA | MST_TIMEOUT_ENA, &regs->dma_master);
+
+       /* hw handles set_address, set_feature, get_status; maybe more */
+       writel(   G_REQMODE_SET_INTF | G_REQMODE_GET_INTF
+               | G_REQMODE_SET_CONF | G_REQMODE_GET_CONF
+               | G_REQMODE_GET_DESC
+               | G_REQMODE_CLEAR_FEAT
+               , &regs->reqmode);
+
+       for (i = 0; i < 4; i++)
+               dev->ep[i].irqs = 0;
+
+       /* can't modify descriptors after writing UsbReady */
+       for (i = 0; i < DESC_LEN; i++)
+               writel(0, &regs->descriptors[i]);
+       writel(0, &regs->UsbReady);
+
+       /* expect ep0 requests when the host drops reset */
+       writel(PW_RESETB | PW_PULLUP, &regs->power_detect);
+       dev->int_enable = INT_DEVWIDE | INT_EP0;
+       writel(dev->int_enable, &dev->regs->int_enable);
+       readl(&regs->int_enable);
+       dev->gadget.speed = USB_SPEED_FULL;
+       dev->ep0state = EP0_IDLE;
+}
+
+static void udc_enable(struct goku_udc *dev)
+{
+       /* start enumeration now, or after power detect irq */
+       if (readl(&dev->regs->power_detect) & PW_DETECT)
+               ep0_start(dev);
+       else {
+               DBG(dev, "%s\n", __func__);
+               dev->int_enable = INT_PWRDETECT;
+               writel(dev->int_enable, &dev->regs->int_enable);
+       }
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* keeping it simple:
+ * - one bus driver, initted first;
+ * - one function driver, initted second
+ */
+
+/* when a driver is successfully registered, it will receive
+ * control requests including set_configuration(), which enables
+ * non-control requests.  then usb traffic follows until a
+ * disconnect is reported.  then a host may connect again, or
+ * the driver might get unbound.
+ */
+static int goku_udc_start(struct usb_gadget *g,
+               struct usb_gadget_driver *driver)
+{
+       struct goku_udc *dev = to_goku_udc(g);
+
+       /* hook up the driver */
+       driver->driver.bus = NULL;
+       dev->driver = driver;
+
+       /*
+        * then enable host detection and ep0; and we're ready
+        * for set_configuration as well as eventual disconnect.
+        */
+       udc_enable(dev);
+
+       return 0;
+}
+
+static void stop_activity(struct goku_udc *dev)
+{
+       unsigned        i;
+
+       DBG (dev, "%s\n", __func__);
+
+       /* disconnect gadget driver after quiesceing hw and the driver */
+       udc_reset (dev);
+       for (i = 0; i < 4; i++)
+               nuke(&dev->ep [i], -ESHUTDOWN);
+
+       if (dev->driver)
+               udc_enable(dev);
+}
+
+static int goku_udc_stop(struct usb_gadget *g)
+{
+       struct goku_udc *dev = to_goku_udc(g);
+       unsigned long   flags;
+
+       spin_lock_irqsave(&dev->lock, flags);
+       dev->driver = NULL;
+       stop_activity(dev);
+       spin_unlock_irqrestore(&dev->lock, flags);
+
+       return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void ep0_setup(struct goku_udc *dev)
+{
+       struct goku_udc_regs __iomem    *regs = dev->regs;
+       struct usb_ctrlrequest          ctrl;
+       int                             tmp;
+
+       /* read SETUP packet and enter DATA stage */
+       ctrl.bRequestType = readl(&regs->bRequestType);
+       ctrl.bRequest = readl(&regs->bRequest);
+       ctrl.wValue  = cpu_to_le16((readl(&regs->wValueH)  << 8)
+                                       | readl(&regs->wValueL));
+       ctrl.wIndex  = cpu_to_le16((readl(&regs->wIndexH)  << 8)
+                                       | readl(&regs->wIndexL));
+       ctrl.wLength = cpu_to_le16((readl(&regs->wLengthH) << 8)
+                                       | readl(&regs->wLengthL));
+       writel(0, &regs->SetupRecv);
+
+       nuke(&dev->ep[0], 0);
+       dev->ep[0].stopped = 0;
+       if (likely(ctrl.bRequestType & USB_DIR_IN)) {
+               dev->ep[0].is_in = 1;
+               dev->ep0state = EP0_IN;
+               /* detect early status stages */
+               writel(ICONTROL_STATUSNAK, &dev->regs->IntControl);
+       } else {
+               dev->ep[0].is_in = 0;
+               dev->ep0state = EP0_OUT;
+
+               /* NOTE:  CLEAR_FEATURE is done in software so that we can
+                * synchronize transfer restarts after bulk IN stalls.  data
+                * won't even enter the fifo until the halt is cleared.
+                */
+               switch (ctrl.bRequest) {
+               case USB_REQ_CLEAR_FEATURE:
+                       switch (ctrl.bRequestType) {
+                       case USB_RECIP_ENDPOINT:
+                               tmp = le16_to_cpu(ctrl.wIndex) & 0x0f;
+                               /* active endpoint */
+                               if (tmp > 3 ||
+                                   (!dev->ep[tmp].ep.desc && tmp != 0))
+                                       goto stall;
+                               if (ctrl.wIndex & cpu_to_le16(
+                                               USB_DIR_IN)) {
+                                       if (!dev->ep[tmp].is_in)
+                                               goto stall;
+                               } else {
+                                       if (dev->ep[tmp].is_in)
+                                               goto stall;
+                               }
+                               if (ctrl.wValue != cpu_to_le16(
+                                               USB_ENDPOINT_HALT))
+                                       goto stall;
+                               if (tmp)
+                                       goku_clear_halt(&dev->ep[tmp]);
+succeed:
+                               /* start ep0out status stage */
+                               writel(~(1<<0), &regs->EOP);
+                               dev->ep[0].stopped = 1;
+                               dev->ep0state = EP0_STATUS;
+                               return;
+                       case USB_RECIP_DEVICE:
+                               /* device remote wakeup: always clear */
+                               if (ctrl.wValue != cpu_to_le16(1))
+                                       goto stall;
+                               VDBG(dev, "clear dev remote wakeup\n");
+                               goto succeed;
+                       case USB_RECIP_INTERFACE:
+                               goto stall;
+                       default:                /* pass to gadget driver */
+                               break;
+                       }
+                       break;
+               default:
+                       break;
+               }
+       }
+
+#ifdef USB_TRACE
+       VDBG(dev, "SETUP %02x.%02x v%04x i%04x l%04x\n",
+               ctrl.bRequestType, ctrl.bRequest,
+               le16_to_cpu(ctrl.wValue), le16_to_cpu(ctrl.wIndex),
+               le16_to_cpu(ctrl.wLength));
+#endif
+
+       /* hw wants to know when we're configured (or not) */
+       dev->req_config = (ctrl.bRequest == USB_REQ_SET_CONFIGURATION
+                               && ctrl.bRequestType == USB_RECIP_DEVICE);
+       if (unlikely(dev->req_config))
+               dev->configured = (ctrl.wValue != cpu_to_le16(0));
+
+       /* delegate everything to the gadget driver.
+        * it may respond after this irq handler returns.
+        */
+       spin_unlock (&dev->lock);
+       tmp = dev->driver->setup(&dev->gadget, &ctrl);
+       spin_lock (&dev->lock);
+       if (unlikely(tmp < 0)) {
+stall:
+#ifdef USB_TRACE
+               VDBG(dev, "req %02x.%02x protocol STALL; err %d\n",
+                               ctrl.bRequestType, ctrl.bRequest, tmp);
+#endif
+               command(regs, COMMAND_STALL, 0);
+               dev->ep[0].stopped = 1;
+               dev->ep0state = EP0_STALL;
+       }
+
+       /* expect at least one data or status stage irq */
+}
+
+#define ACK(irqbit) { \
+               stat &= ~irqbit; \
+               writel(~irqbit, &regs->int_status); \
+               handled = 1; \
+               }
+
+static irqreturn_t goku_irq(int irq, void *_dev)
+{
+       struct goku_udc                 *dev = _dev;
+       struct goku_udc_regs __iomem    *regs = dev->regs;
+       struct goku_ep                  *ep;
+       u32                             stat, handled = 0;
+       unsigned                        i, rescans = 5;
+
+       spin_lock(&dev->lock);
+
+rescan:
+       stat = readl(&regs->int_status) & dev->int_enable;
+        if (!stat)
+               goto done;
+       dev->irqs++;
+
+       /* device-wide irqs */
+       if (unlikely(stat & INT_DEVWIDE)) {
+               if (stat & INT_SYSERROR) {
+                       ERROR(dev, "system error\n");
+                       stop_activity(dev);
+                       stat = 0;
+                       handled = 1;
+                       // FIXME have a neater way to prevent re-enumeration
+                       dev->driver = NULL;
+                       goto done;
+               }
+               if (stat & INT_PWRDETECT) {
+                       writel(~stat, &regs->int_status);
+                       if (readl(&dev->regs->power_detect) & PW_DETECT) {
+                               VDBG(dev, "connect\n");
+                               ep0_start(dev);
+                       } else {
+                               DBG(dev, "disconnect\n");
+                               if (dev->gadget.speed == USB_SPEED_FULL)
+                                       stop_activity(dev);
+                               dev->ep0state = EP0_DISCONNECT;
+                               dev->int_enable = INT_DEVWIDE;
+                               writel(dev->int_enable, &dev->regs->int_enable);
+                       }
+                       stat = 0;
+                       handled = 1;
+                       goto done;
+               }
+               if (stat & INT_SUSPEND) {
+                       ACK(INT_SUSPEND);
+                       if (readl(&regs->ep_status[0]) & EPxSTATUS_SUSPEND) {
+                               switch (dev->ep0state) {
+                               case EP0_DISCONNECT:
+                               case EP0_SUSPEND:
+                                       goto pm_next;
+                               default:
+                                       break;
+                               }
+                               DBG(dev, "USB suspend\n");
+                               dev->ep0state = EP0_SUSPEND;
+                               if (dev->gadget.speed != USB_SPEED_UNKNOWN
+                                               && dev->driver
+                                               && dev->driver->suspend) {
+                                       spin_unlock(&dev->lock);
+                                       dev->driver->suspend(&dev->gadget);
+                                       spin_lock(&dev->lock);
+                               }
+                       } else {
+                               if (dev->ep0state != EP0_SUSPEND) {
+                                       DBG(dev, "bogus USB resume %d\n",
+                                               dev->ep0state);
+                                       goto pm_next;
+                               }
+                               DBG(dev, "USB resume\n");
+                               dev->ep0state = EP0_IDLE;
+                               if (dev->gadget.speed != USB_SPEED_UNKNOWN
+                                               && dev->driver
+                                               && dev->driver->resume) {
+                                       spin_unlock(&dev->lock);
+                                       dev->driver->resume(&dev->gadget);
+                                       spin_lock(&dev->lock);
+                               }
+                       }
+               }
+pm_next:
+               if (stat & INT_USBRESET) {              /* hub reset done */
+                       ACK(INT_USBRESET);
+                       INFO(dev, "USB reset done, gadget %s\n",
+                               dev->driver->driver.name);
+               }
+               // and INT_ERR on some endpoint's crc/bitstuff/... problem
+       }
+
+       /* progress ep0 setup, data, or status stages.
+        * no transition {EP0_STATUS, EP0_STALL} --> EP0_IDLE; saves irqs
+        */
+       if (stat & INT_SETUP) {
+               ACK(INT_SETUP);
+               dev->ep[0].irqs++;
+               ep0_setup(dev);
+       }
+        if (stat & INT_STATUSNAK) {
+               ACK(INT_STATUSNAK|INT_ENDPOINT0);
+               if (dev->ep0state == EP0_IN) {
+                       ep = &dev->ep[0];
+                       ep->irqs++;
+                       nuke(ep, 0);
+                       writel(~(1<<0), &regs->EOP);
+                       dev->ep0state = EP0_STATUS;
+               }
+       }
+        if (stat & INT_ENDPOINT0) {
+               ACK(INT_ENDPOINT0);
+               ep = &dev->ep[0];
+               ep->irqs++;
+               pio_advance(ep);
+        }
+
+       /* dma completion */
+        if (stat & INT_MSTRDEND) {     /* IN */
+               ACK(INT_MSTRDEND);
+               ep = &dev->ep[UDC_MSTRD_ENDPOINT];
+               ep->irqs++;
+               dma_advance(dev, ep);
+        }
+        if (stat & INT_MSTWREND) {     /* OUT */
+               ACK(INT_MSTWREND);
+               ep = &dev->ep[UDC_MSTWR_ENDPOINT];
+               ep->irqs++;
+               dma_advance(dev, ep);
+        }
+        if (stat & INT_MSTWRTMOUT) {   /* OUT */
+               ACK(INT_MSTWRTMOUT);
+               ep = &dev->ep[UDC_MSTWR_ENDPOINT];
+               ep->irqs++;
+               ERROR(dev, "%s write timeout ?\n", ep->ep.name);
+               // reset dma? then dma_advance()
+        }
+
+       /* pio */
+       for (i = 1; i < 4; i++) {
+               u32             tmp = INT_EPxDATASET(i);
+
+               if (!(stat & tmp))
+                       continue;
+               ep = &dev->ep[i];
+               pio_advance(ep);
+               if (list_empty (&ep->queue))
+                       pio_irq_disable(dev, regs, i);
+               stat &= ~tmp;
+               handled = 1;
+               ep->irqs++;
+       }
+
+       if (rescans--)
+               goto rescan;
+
+done:
+       (void)readl(&regs->int_enable);
+       spin_unlock(&dev->lock);
+       if (stat)
+               DBG(dev, "unhandled irq status: %05x (%05x, %05x)\n", stat,
+                               readl(&regs->int_status), dev->int_enable);
+       return IRQ_RETVAL(handled);
+}
+
+#undef ACK
+
+/*-------------------------------------------------------------------------*/
+
+static void gadget_release(struct device *_dev)
+{
+       struct goku_udc *dev = dev_get_drvdata(_dev);
+
+       kfree(dev);
+}
+
+/* tear down the binding between this driver and the pci device */
+
+static void goku_remove(struct pci_dev *pdev)
+{
+       struct goku_udc         *dev = pci_get_drvdata(pdev);
+
+       DBG(dev, "%s\n", __func__);
+
+       usb_del_gadget_udc(&dev->gadget);
+
+       BUG_ON(dev->driver);
+
+#ifdef CONFIG_USB_GADGET_DEBUG_FILES
+       remove_proc_entry(proc_node_name, NULL);
+#endif
+       if (dev->regs)
+               udc_reset(dev);
+       if (dev->got_irq)
+               free_irq(pdev->irq, dev);
+       if (dev->regs)
+               iounmap(dev->regs);
+       if (dev->got_region)
+               release_mem_region(pci_resource_start (pdev, 0),
+                               pci_resource_len (pdev, 0));
+       if (dev->enabled)
+               pci_disable_device(pdev);
+
+       dev->regs = NULL;
+
+       INFO(dev, "unbind\n");
+}
+
+/* wrap this driver around the specified pci device, but
+ * don't respond over USB until a gadget driver binds to us.
+ */
+
+static int goku_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+       struct goku_udc         *dev = NULL;
+       unsigned long           resource, len;
+       void __iomem            *base = NULL;
+       int                     retval;
+
+       if (!pdev->irq) {
+               printk(KERN_ERR "Check PCI %s IRQ setup!\n", pci_name(pdev));
+               retval = -ENODEV;
+               goto err;
+       }
+
+       /* alloc, and start init */
+       dev = kzalloc (sizeof *dev, GFP_KERNEL);
+       if (dev == NULL){
+               pr_debug("enomem %s\n", pci_name(pdev));
+               retval = -ENOMEM;
+               goto err;
+       }
+
+       spin_lock_init(&dev->lock);
+       dev->pdev = pdev;
+       dev->gadget.ops = &goku_ops;
+       dev->gadget.max_speed = USB_SPEED_FULL;
+
+       /* the "gadget" abstracts/virtualizes the controller */
+       dev->gadget.name = driver_name;
+
+       /* now all the pci goodies ... */
+       retval = pci_enable_device(pdev);
+       if (retval < 0) {
+               DBG(dev, "can't enable, %d\n", retval);
+               goto err;
+       }
+       dev->enabled = 1;
+
+       resource = pci_resource_start(pdev, 0);
+       len = pci_resource_len(pdev, 0);
+       if (!request_mem_region(resource, len, driver_name)) {
+               DBG(dev, "controller already in use\n");
+               retval = -EBUSY;
+               goto err;
+       }
+       dev->got_region = 1;
+
+       base = ioremap_nocache(resource, len);
+       if (base == NULL) {
+               DBG(dev, "can't map memory\n");
+               retval = -EFAULT;
+               goto err;
+       }
+       dev->regs = (struct goku_udc_regs __iomem *) base;
+
+       pci_set_drvdata(pdev, dev);
+       INFO(dev, "%s\n", driver_desc);
+       INFO(dev, "version: " DRIVER_VERSION " %s\n", dmastr());
+       INFO(dev, "irq %d, pci mem %p\n", pdev->irq, base);
+
+       /* init to known state, then setup irqs */
+       udc_reset(dev);
+       udc_reinit (dev);
+       if (request_irq(pdev->irq, goku_irq, IRQF_SHARED,
+                       driver_name, dev) != 0) {
+               DBG(dev, "request interrupt %d failed\n", pdev->irq);
+               retval = -EBUSY;
+               goto err;
+       }
+       dev->got_irq = 1;
+       if (use_dma)
+               pci_set_master(pdev);
+
+
+#ifdef CONFIG_USB_GADGET_DEBUG_FILES
+       proc_create_data(proc_node_name, 0, NULL, &udc_proc_fops, dev);
+#endif
+
+       retval = usb_add_gadget_udc_release(&pdev->dev, &dev->gadget,
+                       gadget_release);
+       if (retval)
+               goto err;
+
+       return 0;
+
+err:
+       if (dev)
+               goku_remove (pdev);
+       return retval;
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+static const struct pci_device_id pci_ids[] = { {
+       .class =        ((PCI_CLASS_SERIAL_USB << 8) | 0xfe),
+       .class_mask =   ~0,
+       .vendor =       0x102f,         /* Toshiba */
+       .device =       0x0107,         /* this UDC */
+       .subvendor =    PCI_ANY_ID,
+       .subdevice =    PCI_ANY_ID,
+
+}, { /* end: all zeroes */ }
+};
+MODULE_DEVICE_TABLE (pci, pci_ids);
+
+static struct pci_driver goku_pci_driver = {
+       .name =         (char *) driver_name,
+       .id_table =     pci_ids,
+
+       .probe =        goku_probe,
+       .remove =       goku_remove,
+
+       /* FIXME add power management support */
+};
+
+module_pci_driver(goku_pci_driver);