Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / usb / host / imx21-hcd.c
diff --git a/kernel/drivers/usb/host/imx21-hcd.c b/kernel/drivers/usb/host/imx21-hcd.c
new file mode 100644 (file)
index 0000000..f542045
--- /dev/null
@@ -0,0 +1,1946 @@
+/*
+ * USB Host Controller Driver for IMX21
+ *
+ * Copyright (C) 2006 Loping Dog Embedded Systems
+ * Copyright (C) 2009 Martin Fuzzey
+ * Originally written by Jay Monkman <jtm@lopingdog.com>
+ * Ported to 2.6.30, debugged and enhanced by Martin Fuzzey
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+ /*
+  * The i.MX21 USB hardware contains
+  *    * 32 transfer descriptors (called ETDs)
+  *    * 4Kb of Data memory
+  *
+  * The data memory is shared between the host and function controllers
+  * (but this driver only supports the host controller)
+  *
+  * So setting up a transfer involves:
+  *    * Allocating a ETD
+  *    * Fill in ETD with appropriate information
+  *    * Allocating data memory (and putting the offset in the ETD)
+  *    * Activate the ETD
+  *    * Get interrupt when done.
+  *
+  * An ETD is assigned to each active endpoint.
+  *
+  * Low resource (ETD and Data memory) situations are handled differently for
+  * isochronous and non insosynchronous transactions :
+  *
+  * Non ISOC transfers are queued if either ETDs or Data memory are unavailable
+  *
+  * ISOC transfers use 2 ETDs per endpoint to achieve double buffering.
+  * They allocate both ETDs and Data memory during URB submission
+  * (and fail if unavailable).
+  */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+
+#include "imx21-hcd.h"
+
+#ifdef CONFIG_DYNAMIC_DEBUG
+#define DEBUG
+#endif
+
+#ifdef DEBUG
+#define DEBUG_LOG_FRAME(imx21, etd, event) \
+       (etd)->event##_frame = readl((imx21)->regs + USBH_FRMNUB)
+#else
+#define DEBUG_LOG_FRAME(imx21, etd, event) do { } while (0)
+#endif
+
+static const char hcd_name[] = "imx21-hcd";
+
+static inline struct imx21 *hcd_to_imx21(struct usb_hcd *hcd)
+{
+       return (struct imx21 *)hcd->hcd_priv;
+}
+
+
+/* =========================================== */
+/* Hardware access helpers                     */
+/* =========================================== */
+
+static inline void set_register_bits(struct imx21 *imx21, u32 offset, u32 mask)
+{
+       void __iomem *reg = imx21->regs + offset;
+       writel(readl(reg) | mask, reg);
+}
+
+static inline void clear_register_bits(struct imx21 *imx21,
+       u32 offset, u32 mask)
+{
+       void __iomem *reg = imx21->regs + offset;
+       writel(readl(reg) & ~mask, reg);
+}
+
+static inline void clear_toggle_bit(struct imx21 *imx21, u32 offset, u32 mask)
+{
+       void __iomem *reg = imx21->regs + offset;
+
+       if (readl(reg) & mask)
+               writel(mask, reg);
+}
+
+static inline void set_toggle_bit(struct imx21 *imx21, u32 offset, u32 mask)
+{
+       void __iomem *reg = imx21->regs + offset;
+
+       if (!(readl(reg) & mask))
+               writel(mask, reg);
+}
+
+static void etd_writel(struct imx21 *imx21, int etd_num, int dword, u32 value)
+{
+       writel(value, imx21->regs + USB_ETD_DWORD(etd_num, dword));
+}
+
+static u32 etd_readl(struct imx21 *imx21, int etd_num, int dword)
+{
+       return readl(imx21->regs + USB_ETD_DWORD(etd_num, dword));
+}
+
+static inline int wrap_frame(int counter)
+{
+       return counter & 0xFFFF;
+}
+
+static inline int frame_after(int frame, int after)
+{
+       /* handle wrapping like jiffies time_afer */
+       return (s16)((s16)after - (s16)frame) < 0;
+}
+
+static int imx21_hc_get_frame(struct usb_hcd *hcd)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+
+       return wrap_frame(readl(imx21->regs + USBH_FRMNUB));
+}
+
+static inline bool unsuitable_for_dma(dma_addr_t addr)
+{
+       return (addr & 3) != 0;
+}
+
+#include "imx21-dbg.c"
+
+static void nonisoc_urb_completed_for_etd(
+       struct imx21 *imx21, struct etd_priv *etd, int status);
+static void schedule_nonisoc_etd(struct imx21 *imx21, struct urb *urb);
+static void free_dmem(struct imx21 *imx21, struct etd_priv *etd);
+
+/* =========================================== */
+/* ETD management                              */
+/* =========================================== */
+
+static int alloc_etd(struct imx21 *imx21)
+{
+       int i;
+       struct etd_priv *etd = imx21->etd;
+
+       for (i = 0; i < USB_NUM_ETD; i++, etd++) {
+               if (etd->alloc == 0) {
+                       memset(etd, 0, sizeof(imx21->etd[0]));
+                       etd->alloc = 1;
+                       debug_etd_allocated(imx21);
+                       return i;
+               }
+       }
+       return -1;
+}
+
+static void disactivate_etd(struct imx21 *imx21, int num)
+{
+       int etd_mask = (1 << num);
+       struct etd_priv *etd = &imx21->etd[num];
+
+       writel(etd_mask, imx21->regs + USBH_ETDENCLR);
+       clear_register_bits(imx21, USBH_ETDDONEEN, etd_mask);
+       writel(etd_mask, imx21->regs + USB_ETDDMACHANLCLR);
+       clear_toggle_bit(imx21, USBH_ETDDONESTAT, etd_mask);
+
+       etd->active_count = 0;
+
+       DEBUG_LOG_FRAME(imx21, etd, disactivated);
+}
+
+static void reset_etd(struct imx21 *imx21, int num)
+{
+       struct etd_priv *etd = imx21->etd + num;
+       int i;
+
+       disactivate_etd(imx21, num);
+
+       for (i = 0; i < 4; i++)
+               etd_writel(imx21, num, i, 0);
+       etd->urb = NULL;
+       etd->ep = NULL;
+       etd->td = NULL;
+       etd->bounce_buffer = NULL;
+}
+
+static void free_etd(struct imx21 *imx21, int num)
+{
+       if (num < 0)
+               return;
+
+       if (num >= USB_NUM_ETD) {
+               dev_err(imx21->dev, "BAD etd=%d!\n", num);
+               return;
+       }
+       if (imx21->etd[num].alloc == 0) {
+               dev_err(imx21->dev, "ETD %d already free!\n", num);
+               return;
+       }
+
+       debug_etd_freed(imx21);
+       reset_etd(imx21, num);
+       memset(&imx21->etd[num], 0, sizeof(imx21->etd[0]));
+}
+
+
+static void setup_etd_dword0(struct imx21 *imx21,
+       int etd_num, struct urb *urb,  u8 dir, u16 maxpacket)
+{
+       etd_writel(imx21, etd_num, 0,
+               ((u32) usb_pipedevice(urb->pipe)) <<  DW0_ADDRESS |
+               ((u32) usb_pipeendpoint(urb->pipe) << DW0_ENDPNT) |
+               ((u32) dir << DW0_DIRECT) |
+               ((u32) ((urb->dev->speed == USB_SPEED_LOW) ?
+                       1 : 0) << DW0_SPEED) |
+               ((u32) fmt_urb_to_etd[usb_pipetype(urb->pipe)] << DW0_FORMAT) |
+               ((u32) maxpacket << DW0_MAXPKTSIZ));
+}
+
+/**
+ * Copy buffer to data controller data memory.
+ * We cannot use memcpy_toio() because the hardware requires 32bit writes
+ */
+static void copy_to_dmem(
+       struct imx21 *imx21, int dmem_offset, void *src, int count)
+{
+       void __iomem *dmem = imx21->regs + USBOTG_DMEM + dmem_offset;
+       u32 word = 0;
+       u8 *p = src;
+       int byte = 0;
+       int i;
+
+       for (i = 0; i < count; i++) {
+               byte = i % 4;
+               word += (*p++ << (byte * 8));
+               if (byte == 3) {
+                       writel(word, dmem);
+                       dmem += 4;
+                       word = 0;
+               }
+       }
+
+       if (count && byte != 3)
+               writel(word, dmem);
+}
+
+static void activate_etd(struct imx21 *imx21, int etd_num, u8 dir)
+{
+       u32 etd_mask = 1 << etd_num;
+       struct etd_priv *etd = &imx21->etd[etd_num];
+
+       if (etd->dma_handle && unsuitable_for_dma(etd->dma_handle)) {
+               /* For non aligned isoc the condition below is always true */
+               if (etd->len <= etd->dmem_size) {
+                       /* Fits into data memory, use PIO */
+                       if (dir != TD_DIR_IN) {
+                               copy_to_dmem(imx21,
+                                               etd->dmem_offset,
+                                               etd->cpu_buffer, etd->len);
+                       }
+                       etd->dma_handle = 0;
+
+               } else {
+                       /* Too big for data memory, use bounce buffer */
+                       enum dma_data_direction dmadir;
+
+                       if (dir == TD_DIR_IN) {
+                               dmadir = DMA_FROM_DEVICE;
+                               etd->bounce_buffer = kmalloc(etd->len,
+                                                               GFP_ATOMIC);
+                       } else {
+                               dmadir = DMA_TO_DEVICE;
+                               etd->bounce_buffer = kmemdup(etd->cpu_buffer,
+                                                               etd->len,
+                                                               GFP_ATOMIC);
+                       }
+                       if (!etd->bounce_buffer) {
+                               dev_err(imx21->dev, "failed bounce alloc\n");
+                               goto err_bounce_alloc;
+                       }
+
+                       etd->dma_handle =
+                               dma_map_single(imx21->dev,
+                                               etd->bounce_buffer,
+                                               etd->len,
+                                               dmadir);
+                       if (dma_mapping_error(imx21->dev, etd->dma_handle)) {
+                               dev_err(imx21->dev, "failed bounce map\n");
+                               goto err_bounce_map;
+                       }
+               }
+       }
+
+       clear_toggle_bit(imx21, USBH_ETDDONESTAT, etd_mask);
+       set_register_bits(imx21, USBH_ETDDONEEN, etd_mask);
+       clear_toggle_bit(imx21, USBH_XFILLSTAT, etd_mask);
+       clear_toggle_bit(imx21, USBH_YFILLSTAT, etd_mask);
+
+       if (etd->dma_handle) {
+               set_register_bits(imx21, USB_ETDDMACHANLCLR, etd_mask);
+               clear_toggle_bit(imx21, USBH_XBUFSTAT, etd_mask);
+               clear_toggle_bit(imx21, USBH_YBUFSTAT, etd_mask);
+               writel(etd->dma_handle, imx21->regs + USB_ETDSMSA(etd_num));
+               set_register_bits(imx21, USB_ETDDMAEN, etd_mask);
+       } else {
+               if (dir != TD_DIR_IN) {
+                       /* need to set for ZLP and PIO */
+                       set_toggle_bit(imx21, USBH_XFILLSTAT, etd_mask);
+                       set_toggle_bit(imx21, USBH_YFILLSTAT, etd_mask);
+               }
+       }
+
+       DEBUG_LOG_FRAME(imx21, etd, activated);
+
+#ifdef DEBUG
+       if (!etd->active_count) {
+               int i;
+               etd->activated_frame = readl(imx21->regs + USBH_FRMNUB);
+               etd->disactivated_frame = -1;
+               etd->last_int_frame = -1;
+               etd->last_req_frame = -1;
+
+               for (i = 0; i < 4; i++)
+                       etd->submitted_dwords[i] = etd_readl(imx21, etd_num, i);
+       }
+#endif
+
+       etd->active_count = 1;
+       writel(etd_mask, imx21->regs + USBH_ETDENSET);
+       return;
+
+err_bounce_map:
+       kfree(etd->bounce_buffer);
+
+err_bounce_alloc:
+       free_dmem(imx21, etd);
+       nonisoc_urb_completed_for_etd(imx21, etd, -ENOMEM);
+}
+
+/* =========================================== */
+/* Data memory management                      */
+/* =========================================== */
+
+static int alloc_dmem(struct imx21 *imx21, unsigned int size,
+                     struct usb_host_endpoint *ep)
+{
+       unsigned int offset = 0;
+       struct imx21_dmem_area *area;
+       struct imx21_dmem_area *tmp;
+
+       size += (~size + 1) & 0x3; /* Round to 4 byte multiple */
+
+       if (size > DMEM_SIZE) {
+               dev_err(imx21->dev, "size=%d > DMEM_SIZE(%d)\n",
+                       size, DMEM_SIZE);
+               return -EINVAL;
+       }
+
+       list_for_each_entry(tmp, &imx21->dmem_list, list) {
+               if ((size + offset) < offset)
+                       goto fail;
+               if ((size + offset) <= tmp->offset)
+                       break;
+               offset = tmp->size + tmp->offset;
+               if ((offset + size) > DMEM_SIZE)
+                       goto fail;
+       }
+
+       area = kmalloc(sizeof(struct imx21_dmem_area), GFP_ATOMIC);
+       if (area == NULL)
+               return -ENOMEM;
+
+       area->ep = ep;
+       area->offset = offset;
+       area->size = size;
+       list_add_tail(&area->list, &tmp->list);
+       debug_dmem_allocated(imx21, size);
+       return offset;
+
+fail:
+       return -ENOMEM;
+}
+
+/* Memory now available for a queued ETD - activate it */
+static void activate_queued_etd(struct imx21 *imx21,
+       struct etd_priv *etd, u32 dmem_offset)
+{
+       struct urb_priv *urb_priv = etd->urb->hcpriv;
+       int etd_num = etd - &imx21->etd[0];
+       u32 maxpacket = etd_readl(imx21, etd_num, 1) >> DW1_YBUFSRTAD;
+       u8 dir = (etd_readl(imx21, etd_num, 2) >> DW2_DIRPID) & 0x03;
+
+       dev_dbg(imx21->dev, "activating queued ETD %d now DMEM available\n",
+               etd_num);
+       etd_writel(imx21, etd_num, 1,
+           ((dmem_offset + maxpacket) << DW1_YBUFSRTAD) | dmem_offset);
+
+       etd->dmem_offset = dmem_offset;
+       urb_priv->active = 1;
+       activate_etd(imx21, etd_num, dir);
+}
+
+static void free_dmem(struct imx21 *imx21, struct etd_priv *etd)
+{
+       struct imx21_dmem_area *area;
+       struct etd_priv *tmp;
+       int found = 0;
+       int offset;
+
+       if (!etd->dmem_size)
+               return;
+       etd->dmem_size = 0;
+
+       offset = etd->dmem_offset;
+       list_for_each_entry(area, &imx21->dmem_list, list) {
+               if (area->offset == offset) {
+                       debug_dmem_freed(imx21, area->size);
+                       list_del(&area->list);
+                       kfree(area);
+                       found = 1;
+                       break;
+               }
+       }
+
+       if (!found)  {
+               dev_err(imx21->dev,
+                       "Trying to free unallocated DMEM %d\n", offset);
+               return;
+       }
+
+       /* Try again to allocate memory for anything we've queued */
+       list_for_each_entry_safe(etd, tmp, &imx21->queue_for_dmem, queue) {
+               offset = alloc_dmem(imx21, etd->dmem_size, etd->ep);
+               if (offset >= 0) {
+                       list_del(&etd->queue);
+                       activate_queued_etd(imx21, etd, (u32)offset);
+               }
+       }
+}
+
+static void free_epdmem(struct imx21 *imx21, struct usb_host_endpoint *ep)
+{
+       struct imx21_dmem_area *area, *tmp;
+
+       list_for_each_entry_safe(area, tmp, &imx21->dmem_list, list) {
+               if (area->ep == ep) {
+                       dev_err(imx21->dev,
+                               "Active DMEM %d for disabled ep=%p\n",
+                               area->offset, ep);
+                       list_del(&area->list);
+                       kfree(area);
+               }
+       }
+}
+
+
+/* =========================================== */
+/* End handling                                */
+/* =========================================== */
+
+/* Endpoint now idle - release its ETD(s) or assign to queued request */
+static void ep_idle(struct imx21 *imx21, struct ep_priv *ep_priv)
+{
+       int i;
+
+       for (i = 0; i < NUM_ISO_ETDS; i++) {
+               int etd_num = ep_priv->etd[i];
+               struct etd_priv *etd;
+               if (etd_num < 0)
+                       continue;
+
+               etd = &imx21->etd[etd_num];
+               ep_priv->etd[i] = -1;
+
+               free_dmem(imx21, etd); /* for isoc */
+
+               if (list_empty(&imx21->queue_for_etd)) {
+                       free_etd(imx21, etd_num);
+                       continue;
+               }
+
+               dev_dbg(imx21->dev,
+                       "assigning idle etd %d for queued request\n", etd_num);
+               ep_priv = list_first_entry(&imx21->queue_for_etd,
+                       struct ep_priv, queue);
+               list_del(&ep_priv->queue);
+               reset_etd(imx21, etd_num);
+               ep_priv->waiting_etd = 0;
+               ep_priv->etd[i] = etd_num;
+
+               if (list_empty(&ep_priv->ep->urb_list)) {
+                       dev_err(imx21->dev, "No urb for queued ep!\n");
+                       continue;
+               }
+               schedule_nonisoc_etd(imx21, list_first_entry(
+                       &ep_priv->ep->urb_list, struct urb, urb_list));
+       }
+}
+
+static void urb_done(struct usb_hcd *hcd, struct urb *urb, int status)
+__releases(imx21->lock)
+__acquires(imx21->lock)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       struct ep_priv *ep_priv = urb->ep->hcpriv;
+       struct urb_priv *urb_priv = urb->hcpriv;
+
+       debug_urb_completed(imx21, urb, status);
+       dev_vdbg(imx21->dev, "urb %p done %d\n", urb, status);
+
+       kfree(urb_priv->isoc_td);
+       kfree(urb->hcpriv);
+       urb->hcpriv = NULL;
+       usb_hcd_unlink_urb_from_ep(hcd, urb);
+       spin_unlock(&imx21->lock);
+       usb_hcd_giveback_urb(hcd, urb, status);
+       spin_lock(&imx21->lock);
+       if (list_empty(&ep_priv->ep->urb_list))
+               ep_idle(imx21, ep_priv);
+}
+
+static void nonisoc_urb_completed_for_etd(
+       struct imx21 *imx21, struct etd_priv *etd, int status)
+{
+       struct usb_host_endpoint *ep = etd->ep;
+
+       urb_done(imx21->hcd, etd->urb, status);
+       etd->urb = NULL;
+
+       if (!list_empty(&ep->urb_list)) {
+               struct urb *urb = list_first_entry(
+                                       &ep->urb_list, struct urb, urb_list);
+
+               dev_vdbg(imx21->dev, "next URB %p\n", urb);
+               schedule_nonisoc_etd(imx21, urb);
+       }
+}
+
+
+/* =========================================== */
+/* ISOC Handling ...                           */
+/* =========================================== */
+
+static void schedule_isoc_etds(struct usb_hcd *hcd,
+       struct usb_host_endpoint *ep)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       struct ep_priv *ep_priv = ep->hcpriv;
+       struct etd_priv *etd;
+       struct urb_priv *urb_priv;
+       struct td *td;
+       int etd_num;
+       int i;
+       int cur_frame;
+       u8 dir;
+
+       for (i = 0; i < NUM_ISO_ETDS; i++) {
+too_late:
+               if (list_empty(&ep_priv->td_list))
+                       break;
+
+               etd_num = ep_priv->etd[i];
+               if (etd_num < 0)
+                       break;
+
+               etd = &imx21->etd[etd_num];
+               if (etd->urb)
+                       continue;
+
+               td = list_entry(ep_priv->td_list.next, struct td, list);
+               list_del(&td->list);
+               urb_priv = td->urb->hcpriv;
+
+               cur_frame = imx21_hc_get_frame(hcd);
+               if (frame_after(cur_frame, td->frame)) {
+                       dev_dbg(imx21->dev, "isoc too late frame %d > %d\n",
+                               cur_frame, td->frame);
+                       urb_priv->isoc_status = -EXDEV;
+                       td->urb->iso_frame_desc[
+                               td->isoc_index].actual_length = 0;
+                       td->urb->iso_frame_desc[td->isoc_index].status = -EXDEV;
+                       if (--urb_priv->isoc_remaining == 0)
+                               urb_done(hcd, td->urb, urb_priv->isoc_status);
+                       goto too_late;
+               }
+
+               urb_priv->active = 1;
+               etd->td = td;
+               etd->ep = td->ep;
+               etd->urb = td->urb;
+               etd->len = td->len;
+               etd->dma_handle = td->dma_handle;
+               etd->cpu_buffer = td->cpu_buffer;
+
+               debug_isoc_submitted(imx21, cur_frame, td);
+
+               dir = usb_pipeout(td->urb->pipe) ? TD_DIR_OUT : TD_DIR_IN;
+               setup_etd_dword0(imx21, etd_num, td->urb, dir, etd->dmem_size);
+               etd_writel(imx21, etd_num, 1, etd->dmem_offset);
+               etd_writel(imx21, etd_num, 2,
+                       (TD_NOTACCESSED << DW2_COMPCODE) |
+                       ((td->frame & 0xFFFF) << DW2_STARTFRM));
+               etd_writel(imx21, etd_num, 3,
+                       (TD_NOTACCESSED << DW3_COMPCODE0) |
+                       (td->len << DW3_PKTLEN0));
+
+               activate_etd(imx21, etd_num, dir);
+       }
+}
+
+static void isoc_etd_done(struct usb_hcd *hcd, int etd_num)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       int etd_mask = 1 << etd_num;
+       struct etd_priv *etd = imx21->etd + etd_num;
+       struct urb *urb = etd->urb;
+       struct urb_priv *urb_priv = urb->hcpriv;
+       struct td *td = etd->td;
+       struct usb_host_endpoint *ep = etd->ep;
+       int isoc_index = td->isoc_index;
+       unsigned int pipe = urb->pipe;
+       int dir_in = usb_pipein(pipe);
+       int cc;
+       int bytes_xfrd;
+
+       disactivate_etd(imx21, etd_num);
+
+       cc = (etd_readl(imx21, etd_num, 3) >> DW3_COMPCODE0) & 0xf;
+       bytes_xfrd = etd_readl(imx21, etd_num, 3) & 0x3ff;
+
+       /* Input doesn't always fill the buffer, don't generate an error
+        * when this happens.
+        */
+       if (dir_in && (cc == TD_DATAUNDERRUN))
+               cc = TD_CC_NOERROR;
+
+       if (cc == TD_NOTACCESSED)
+               bytes_xfrd = 0;
+
+       debug_isoc_completed(imx21,
+               imx21_hc_get_frame(hcd), td, cc, bytes_xfrd);
+       if (cc) {
+               urb_priv->isoc_status = -EXDEV;
+               dev_dbg(imx21->dev,
+                       "bad iso cc=0x%X frame=%d sched frame=%d "
+                       "cnt=%d len=%d urb=%p etd=%d index=%d\n",
+                       cc,  imx21_hc_get_frame(hcd), td->frame,
+                       bytes_xfrd, td->len, urb, etd_num, isoc_index);
+       }
+
+       if (dir_in) {
+               clear_toggle_bit(imx21, USBH_XFILLSTAT, etd_mask);
+               if (!etd->dma_handle)
+                       memcpy_fromio(etd->cpu_buffer,
+                               imx21->regs + USBOTG_DMEM + etd->dmem_offset,
+                               bytes_xfrd);
+       }
+
+       urb->actual_length += bytes_xfrd;
+       urb->iso_frame_desc[isoc_index].actual_length = bytes_xfrd;
+       urb->iso_frame_desc[isoc_index].status = cc_to_error[cc];
+
+       etd->td = NULL;
+       etd->urb = NULL;
+       etd->ep = NULL;
+
+       if (--urb_priv->isoc_remaining == 0)
+               urb_done(hcd, urb, urb_priv->isoc_status);
+
+       schedule_isoc_etds(hcd, ep);
+}
+
+static struct ep_priv *alloc_isoc_ep(
+       struct imx21 *imx21, struct usb_host_endpoint *ep)
+{
+       struct ep_priv *ep_priv;
+       int i;
+
+       ep_priv = kzalloc(sizeof(struct ep_priv), GFP_ATOMIC);
+       if (!ep_priv)
+               return NULL;
+
+       for (i = 0; i < NUM_ISO_ETDS; i++)
+               ep_priv->etd[i] = -1;
+
+       INIT_LIST_HEAD(&ep_priv->td_list);
+       ep_priv->ep = ep;
+       ep->hcpriv = ep_priv;
+       return ep_priv;
+}
+
+static int alloc_isoc_etds(struct imx21 *imx21, struct ep_priv *ep_priv)
+{
+       int i, j;
+       int etd_num;
+
+       /* Allocate the ETDs if required */
+       for (i = 0; i < NUM_ISO_ETDS; i++) {
+               if (ep_priv->etd[i] < 0) {
+                       etd_num = alloc_etd(imx21);
+                       if (etd_num < 0)
+                               goto alloc_etd_failed;
+
+                       ep_priv->etd[i] = etd_num;
+                       imx21->etd[etd_num].ep = ep_priv->ep;
+               }
+       }
+       return 0;
+
+alloc_etd_failed:
+       dev_err(imx21->dev, "isoc: Couldn't allocate etd\n");
+       for (j = 0; j < i; j++) {
+               free_etd(imx21, ep_priv->etd[j]);
+               ep_priv->etd[j] = -1;
+       }
+       return -ENOMEM;
+}
+
+static int imx21_hc_urb_enqueue_isoc(struct usb_hcd *hcd,
+                                    struct usb_host_endpoint *ep,
+                                    struct urb *urb, gfp_t mem_flags)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       struct urb_priv *urb_priv;
+       unsigned long flags;
+       struct ep_priv *ep_priv;
+       struct td *td = NULL;
+       int i;
+       int ret;
+       int cur_frame;
+       u16 maxpacket;
+
+       urb_priv = kzalloc(sizeof(struct urb_priv), mem_flags);
+       if (urb_priv == NULL)
+               return -ENOMEM;
+
+       urb_priv->isoc_td = kzalloc(
+               sizeof(struct td) * urb->number_of_packets, mem_flags);
+       if (urb_priv->isoc_td == NULL) {
+               ret = -ENOMEM;
+               goto alloc_td_failed;
+       }
+
+       spin_lock_irqsave(&imx21->lock, flags);
+
+       if (ep->hcpriv == NULL) {
+               ep_priv = alloc_isoc_ep(imx21, ep);
+               if (ep_priv == NULL) {
+                       ret = -ENOMEM;
+                       goto alloc_ep_failed;
+               }
+       } else {
+               ep_priv = ep->hcpriv;
+       }
+
+       ret = alloc_isoc_etds(imx21, ep_priv);
+       if (ret)
+               goto alloc_etd_failed;
+
+       ret = usb_hcd_link_urb_to_ep(hcd, urb);
+       if (ret)
+               goto link_failed;
+
+       urb->status = -EINPROGRESS;
+       urb->actual_length = 0;
+       urb->error_count = 0;
+       urb->hcpriv = urb_priv;
+       urb_priv->ep = ep;
+
+       /* allocate data memory for largest packets if not already done */
+       maxpacket = usb_maxpacket(urb->dev, urb->pipe, usb_pipeout(urb->pipe));
+       for (i = 0; i < NUM_ISO_ETDS; i++) {
+               struct etd_priv *etd = &imx21->etd[ep_priv->etd[i]];
+
+               if (etd->dmem_size > 0 && etd->dmem_size < maxpacket) {
+                       /* not sure if this can really occur.... */
+                       dev_err(imx21->dev, "increasing isoc buffer %d->%d\n",
+                               etd->dmem_size, maxpacket);
+                       ret = -EMSGSIZE;
+                       goto alloc_dmem_failed;
+               }
+
+               if (etd->dmem_size == 0) {
+                       etd->dmem_offset = alloc_dmem(imx21, maxpacket, ep);
+                       if (etd->dmem_offset < 0) {
+                               dev_dbg(imx21->dev, "failed alloc isoc dmem\n");
+                               ret = -EAGAIN;
+                               goto alloc_dmem_failed;
+                       }
+                       etd->dmem_size = maxpacket;
+               }
+       }
+
+       /* calculate frame */
+       cur_frame = imx21_hc_get_frame(hcd);
+       i = 0;
+       if (list_empty(&ep_priv->td_list)) {
+               urb->start_frame = wrap_frame(cur_frame + 5);
+       } else {
+               urb->start_frame = wrap_frame(list_entry(ep_priv->td_list.prev,
+                               struct td, list)->frame + urb->interval);
+
+               if (frame_after(cur_frame, urb->start_frame)) {
+                       dev_dbg(imx21->dev,
+                               "enqueue: adjusting iso start %d (cur=%d) asap=%d\n",
+                               urb->start_frame, cur_frame,
+                               (urb->transfer_flags & URB_ISO_ASAP) != 0);
+                       i = DIV_ROUND_UP(wrap_frame(
+                                       cur_frame - urb->start_frame),
+                                       urb->interval);
+
+                       /* Treat underruns as if URB_ISO_ASAP was set */
+                       if ((urb->transfer_flags & URB_ISO_ASAP) ||
+                                       i >= urb->number_of_packets) {
+                               urb->start_frame = wrap_frame(urb->start_frame
+                                               + i * urb->interval);
+                               i = 0;
+                       }
+               }
+       }
+
+       /* set up transfers */
+       urb_priv->isoc_remaining = urb->number_of_packets - i;
+       td = urb_priv->isoc_td;
+       for (; i < urb->number_of_packets; i++, td++) {
+               unsigned int offset = urb->iso_frame_desc[i].offset;
+               td->ep = ep;
+               td->urb = urb;
+               td->len = urb->iso_frame_desc[i].length;
+               td->isoc_index = i;
+               td->frame = wrap_frame(urb->start_frame + urb->interval * i);
+               td->dma_handle = urb->transfer_dma + offset;
+               td->cpu_buffer = urb->transfer_buffer + offset;
+               list_add_tail(&td->list, &ep_priv->td_list);
+       }
+
+       dev_vdbg(imx21->dev, "setup %d packets for iso frame %d->%d\n",
+               urb->number_of_packets, urb->start_frame, td->frame);
+
+       debug_urb_submitted(imx21, urb);
+       schedule_isoc_etds(hcd, ep);
+
+       spin_unlock_irqrestore(&imx21->lock, flags);
+       return 0;
+
+alloc_dmem_failed:
+       usb_hcd_unlink_urb_from_ep(hcd, urb);
+
+link_failed:
+alloc_etd_failed:
+alloc_ep_failed:
+       spin_unlock_irqrestore(&imx21->lock, flags);
+       kfree(urb_priv->isoc_td);
+
+alloc_td_failed:
+       kfree(urb_priv);
+       return ret;
+}
+
+static void dequeue_isoc_urb(struct imx21 *imx21,
+       struct urb *urb, struct ep_priv *ep_priv)
+{
+       struct urb_priv *urb_priv = urb->hcpriv;
+       struct td *td, *tmp;
+       int i;
+
+       if (urb_priv->active) {
+               for (i = 0; i < NUM_ISO_ETDS; i++) {
+                       int etd_num = ep_priv->etd[i];
+                       if (etd_num != -1 && imx21->etd[etd_num].urb == urb) {
+                               struct etd_priv *etd = imx21->etd + etd_num;
+
+                               reset_etd(imx21, etd_num);
+                               free_dmem(imx21, etd);
+                       }
+               }
+       }
+
+       list_for_each_entry_safe(td, tmp, &ep_priv->td_list, list) {
+               if (td->urb == urb) {
+                       dev_vdbg(imx21->dev, "removing td %p\n", td);
+                       list_del(&td->list);
+               }
+       }
+}
+
+/* =========================================== */
+/* NON ISOC Handling ...                       */
+/* =========================================== */
+
+static void schedule_nonisoc_etd(struct imx21 *imx21, struct urb *urb)
+{
+       unsigned int pipe = urb->pipe;
+       struct urb_priv *urb_priv = urb->hcpriv;
+       struct ep_priv *ep_priv = urb_priv->ep->hcpriv;
+       int state = urb_priv->state;
+       int etd_num = ep_priv->etd[0];
+       struct etd_priv *etd;
+       u32 count;
+       u16 etd_buf_size;
+       u16 maxpacket;
+       u8 dir;
+       u8 bufround;
+       u8 datatoggle;
+       u8 interval = 0;
+       u8 relpolpos = 0;
+
+       if (etd_num < 0) {
+               dev_err(imx21->dev, "No valid ETD\n");
+               return;
+       }
+       if (readl(imx21->regs + USBH_ETDENSET) & (1 << etd_num))
+               dev_err(imx21->dev, "submitting to active ETD %d\n", etd_num);
+
+       etd = &imx21->etd[etd_num];
+       maxpacket = usb_maxpacket(urb->dev, pipe, usb_pipeout(pipe));
+       if (!maxpacket)
+               maxpacket = 8;
+
+       if (usb_pipecontrol(pipe) && (state != US_CTRL_DATA)) {
+               if (state == US_CTRL_SETUP) {
+                       dir = TD_DIR_SETUP;
+                       if (unsuitable_for_dma(urb->setup_dma))
+                               usb_hcd_unmap_urb_setup_for_dma(imx21->hcd,
+                                       urb);
+                       etd->dma_handle = urb->setup_dma;
+                       etd->cpu_buffer = urb->setup_packet;
+                       bufround = 0;
+                       count = 8;
+                       datatoggle = TD_TOGGLE_DATA0;
+               } else {        /* US_CTRL_ACK */
+                       dir = usb_pipeout(pipe) ? TD_DIR_IN : TD_DIR_OUT;
+                       bufround = 0;
+                       count = 0;
+                       datatoggle = TD_TOGGLE_DATA1;
+               }
+       } else {
+               dir = usb_pipeout(pipe) ? TD_DIR_OUT : TD_DIR_IN;
+               bufround = (dir == TD_DIR_IN) ? 1 : 0;
+               if (unsuitable_for_dma(urb->transfer_dma))
+                       usb_hcd_unmap_urb_for_dma(imx21->hcd, urb);
+
+               etd->dma_handle = urb->transfer_dma;
+               etd->cpu_buffer = urb->transfer_buffer;
+               if (usb_pipebulk(pipe) && (state == US_BULK0))
+                       count = 0;
+               else
+                       count = urb->transfer_buffer_length;
+
+               if (usb_pipecontrol(pipe)) {
+                       datatoggle = TD_TOGGLE_DATA1;
+               } else {
+                       if (usb_gettoggle(
+                                       urb->dev,
+                                       usb_pipeendpoint(urb->pipe),
+                                       usb_pipeout(urb->pipe)))
+                               datatoggle = TD_TOGGLE_DATA1;
+                       else
+                               datatoggle = TD_TOGGLE_DATA0;
+               }
+       }
+
+       etd->urb = urb;
+       etd->ep = urb_priv->ep;
+       etd->len = count;
+
+       if (usb_pipeint(pipe)) {
+               interval = urb->interval;
+               relpolpos = (readl(imx21->regs + USBH_FRMNUB) + 1) & 0xff;
+       }
+
+       /* Write ETD to device memory */
+       setup_etd_dword0(imx21, etd_num, urb, dir, maxpacket);
+
+       etd_writel(imx21, etd_num, 2,
+               (u32) interval << DW2_POLINTERV |
+               ((u32) relpolpos << DW2_RELPOLPOS) |
+               ((u32) dir << DW2_DIRPID) |
+               ((u32) bufround << DW2_BUFROUND) |
+               ((u32) datatoggle << DW2_DATATOG) |
+               ((u32) TD_NOTACCESSED << DW2_COMPCODE));
+
+       /* DMA will always transfer buffer size even if TOBYCNT in DWORD3
+          is smaller. Make sure we don't overrun the buffer!
+        */
+       if (count && count < maxpacket)
+               etd_buf_size = count;
+       else
+               etd_buf_size = maxpacket;
+
+       etd_writel(imx21, etd_num, 3,
+               ((u32) (etd_buf_size - 1) << DW3_BUFSIZE) | (u32) count);
+
+       if (!count)
+               etd->dma_handle = 0;
+
+       /* allocate x and y buffer space at once */
+       etd->dmem_size = (count > maxpacket) ? maxpacket * 2 : maxpacket;
+       etd->dmem_offset = alloc_dmem(imx21, etd->dmem_size, urb_priv->ep);
+       if (etd->dmem_offset < 0) {
+               /* Setup everything we can in HW and update when we get DMEM */
+               etd_writel(imx21, etd_num, 1, (u32)maxpacket << 16);
+
+               dev_dbg(imx21->dev, "Queuing etd %d for DMEM\n", etd_num);
+               debug_urb_queued_for_dmem(imx21, urb);
+               list_add_tail(&etd->queue, &imx21->queue_for_dmem);
+               return;
+       }
+
+       etd_writel(imx21, etd_num, 1,
+               (((u32) etd->dmem_offset + (u32) maxpacket) << DW1_YBUFSRTAD) |
+               (u32) etd->dmem_offset);
+
+       urb_priv->active = 1;
+
+       /* enable the ETD to kick off transfer */
+       dev_vdbg(imx21->dev, "Activating etd %d for %d bytes %s\n",
+               etd_num, count, dir != TD_DIR_IN ? "out" : "in");
+       activate_etd(imx21, etd_num, dir);
+
+}
+
+static void nonisoc_etd_done(struct usb_hcd *hcd, int etd_num)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       struct etd_priv *etd = &imx21->etd[etd_num];
+       struct urb *urb = etd->urb;
+       u32 etd_mask = 1 << etd_num;
+       struct urb_priv *urb_priv = urb->hcpriv;
+       int dir;
+       int cc;
+       u32 bytes_xfrd;
+       int etd_done;
+
+       disactivate_etd(imx21, etd_num);
+
+       dir = (etd_readl(imx21, etd_num, 0) >> DW0_DIRECT) & 0x3;
+       cc = (etd_readl(imx21, etd_num, 2) >> DW2_COMPCODE) & 0xf;
+       bytes_xfrd = etd->len - (etd_readl(imx21, etd_num, 3) & 0x1fffff);
+
+       /* save toggle carry */
+       usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
+                     usb_pipeout(urb->pipe),
+                     (etd_readl(imx21, etd_num, 0) >> DW0_TOGCRY) & 0x1);
+
+       if (dir == TD_DIR_IN) {
+               clear_toggle_bit(imx21, USBH_XFILLSTAT, etd_mask);
+               clear_toggle_bit(imx21, USBH_YFILLSTAT, etd_mask);
+
+               if (etd->bounce_buffer) {
+                       memcpy(etd->cpu_buffer, etd->bounce_buffer, bytes_xfrd);
+                       dma_unmap_single(imx21->dev,
+                               etd->dma_handle, etd->len, DMA_FROM_DEVICE);
+               } else if (!etd->dma_handle && bytes_xfrd) {/* PIO */
+                       memcpy_fromio(etd->cpu_buffer,
+                               imx21->regs + USBOTG_DMEM + etd->dmem_offset,
+                               bytes_xfrd);
+               }
+       }
+
+       kfree(etd->bounce_buffer);
+       etd->bounce_buffer = NULL;
+       free_dmem(imx21, etd);
+
+       urb->error_count = 0;
+       if (!(urb->transfer_flags & URB_SHORT_NOT_OK)
+                       && (cc == TD_DATAUNDERRUN))
+               cc = TD_CC_NOERROR;
+
+       if (cc != 0)
+               dev_vdbg(imx21->dev, "cc is 0x%x\n", cc);
+
+       etd_done = (cc_to_error[cc] != 0);      /* stop if error */
+
+       switch (usb_pipetype(urb->pipe)) {
+       case PIPE_CONTROL:
+               switch (urb_priv->state) {
+               case US_CTRL_SETUP:
+                       if (urb->transfer_buffer_length > 0)
+                               urb_priv->state = US_CTRL_DATA;
+                       else
+                               urb_priv->state = US_CTRL_ACK;
+                       break;
+               case US_CTRL_DATA:
+                       urb->actual_length += bytes_xfrd;
+                       urb_priv->state = US_CTRL_ACK;
+                       break;
+               case US_CTRL_ACK:
+                       etd_done = 1;
+                       break;
+               default:
+                       dev_err(imx21->dev,
+                               "Invalid pipe state %d\n", urb_priv->state);
+                       etd_done = 1;
+                       break;
+               }
+               break;
+
+       case PIPE_BULK:
+               urb->actual_length += bytes_xfrd;
+               if ((urb_priv->state == US_BULK)
+                   && (urb->transfer_flags & URB_ZERO_PACKET)
+                   && urb->transfer_buffer_length > 0
+                   && ((urb->transfer_buffer_length %
+                        usb_maxpacket(urb->dev, urb->pipe,
+                                      usb_pipeout(urb->pipe))) == 0)) {
+                       /* need a 0-packet */
+                       urb_priv->state = US_BULK0;
+               } else {
+                       etd_done = 1;
+               }
+               break;
+
+       case PIPE_INTERRUPT:
+               urb->actual_length += bytes_xfrd;
+               etd_done = 1;
+               break;
+       }
+
+       if (etd_done)
+               nonisoc_urb_completed_for_etd(imx21, etd, cc_to_error[cc]);
+       else {
+               dev_vdbg(imx21->dev, "next state=%d\n", urb_priv->state);
+               schedule_nonisoc_etd(imx21, urb);
+       }
+}
+
+
+static struct ep_priv *alloc_ep(void)
+{
+       int i;
+       struct ep_priv *ep_priv;
+
+       ep_priv = kzalloc(sizeof(struct ep_priv), GFP_ATOMIC);
+       if (!ep_priv)
+               return NULL;
+
+       for (i = 0; i < NUM_ISO_ETDS; ++i)
+               ep_priv->etd[i] = -1;
+
+       return ep_priv;
+}
+
+static int imx21_hc_urb_enqueue(struct usb_hcd *hcd,
+                               struct urb *urb, gfp_t mem_flags)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       struct usb_host_endpoint *ep = urb->ep;
+       struct urb_priv *urb_priv;
+       struct ep_priv *ep_priv;
+       struct etd_priv *etd;
+       int ret;
+       unsigned long flags;
+
+       dev_vdbg(imx21->dev,
+               "enqueue urb=%p ep=%p len=%d "
+               "buffer=%p dma=%pad setupBuf=%p setupDma=%pad\n",
+               urb, ep,
+               urb->transfer_buffer_length,
+               urb->transfer_buffer, &urb->transfer_dma,
+               urb->setup_packet, &urb->setup_dma);
+
+       if (usb_pipeisoc(urb->pipe))
+               return imx21_hc_urb_enqueue_isoc(hcd, ep, urb, mem_flags);
+
+       urb_priv = kzalloc(sizeof(struct urb_priv), mem_flags);
+       if (!urb_priv)
+               return -ENOMEM;
+
+       spin_lock_irqsave(&imx21->lock, flags);
+
+       ep_priv = ep->hcpriv;
+       if (ep_priv == NULL) {
+               ep_priv = alloc_ep();
+               if (!ep_priv) {
+                       ret = -ENOMEM;
+                       goto failed_alloc_ep;
+               }
+               ep->hcpriv = ep_priv;
+               ep_priv->ep = ep;
+       }
+
+       ret = usb_hcd_link_urb_to_ep(hcd, urb);
+       if (ret)
+               goto failed_link;
+
+       urb->status = -EINPROGRESS;
+       urb->actual_length = 0;
+       urb->error_count = 0;
+       urb->hcpriv = urb_priv;
+       urb_priv->ep = ep;
+
+       switch (usb_pipetype(urb->pipe)) {
+       case PIPE_CONTROL:
+               urb_priv->state = US_CTRL_SETUP;
+               break;
+       case PIPE_BULK:
+               urb_priv->state = US_BULK;
+               break;
+       }
+
+       debug_urb_submitted(imx21, urb);
+       if (ep_priv->etd[0] < 0) {
+               if (ep_priv->waiting_etd) {
+                       dev_dbg(imx21->dev,
+                               "no ETD available already queued %p\n",
+                               ep_priv);
+                       debug_urb_queued_for_etd(imx21, urb);
+                       goto out;
+               }
+               ep_priv->etd[0] = alloc_etd(imx21);
+               if (ep_priv->etd[0] < 0) {
+                       dev_dbg(imx21->dev,
+                               "no ETD available queueing %p\n", ep_priv);
+                       debug_urb_queued_for_etd(imx21, urb);
+                       list_add_tail(&ep_priv->queue, &imx21->queue_for_etd);
+                       ep_priv->waiting_etd = 1;
+                       goto out;
+               }
+       }
+
+       /* Schedule if no URB already active for this endpoint */
+       etd = &imx21->etd[ep_priv->etd[0]];
+       if (etd->urb == NULL) {
+               DEBUG_LOG_FRAME(imx21, etd, last_req);
+               schedule_nonisoc_etd(imx21, urb);
+       }
+
+out:
+       spin_unlock_irqrestore(&imx21->lock, flags);
+       return 0;
+
+failed_link:
+failed_alloc_ep:
+       spin_unlock_irqrestore(&imx21->lock, flags);
+       kfree(urb_priv);
+       return ret;
+}
+
+static int imx21_hc_urb_dequeue(struct usb_hcd *hcd, struct urb *urb,
+                               int status)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       unsigned long flags;
+       struct usb_host_endpoint *ep;
+       struct ep_priv *ep_priv;
+       struct urb_priv *urb_priv = urb->hcpriv;
+       int ret = -EINVAL;
+
+       dev_vdbg(imx21->dev, "dequeue urb=%p iso=%d status=%d\n",
+               urb, usb_pipeisoc(urb->pipe), status);
+
+       spin_lock_irqsave(&imx21->lock, flags);
+
+       ret = usb_hcd_check_unlink_urb(hcd, urb, status);
+       if (ret)
+               goto fail;
+       ep = urb_priv->ep;
+       ep_priv = ep->hcpriv;
+
+       debug_urb_unlinked(imx21, urb);
+
+       if (usb_pipeisoc(urb->pipe)) {
+               dequeue_isoc_urb(imx21, urb, ep_priv);
+               schedule_isoc_etds(hcd, ep);
+       } else if (urb_priv->active) {
+               int etd_num = ep_priv->etd[0];
+               if (etd_num != -1) {
+                       struct etd_priv *etd = &imx21->etd[etd_num];
+
+                       disactivate_etd(imx21, etd_num);
+                       free_dmem(imx21, etd);
+                       etd->urb = NULL;
+                       kfree(etd->bounce_buffer);
+                       etd->bounce_buffer = NULL;
+               }
+       }
+
+       urb_done(hcd, urb, status);
+
+       spin_unlock_irqrestore(&imx21->lock, flags);
+       return 0;
+
+fail:
+       spin_unlock_irqrestore(&imx21->lock, flags);
+       return ret;
+}
+
+/* =========================================== */
+/* Interrupt dispatch                          */
+/* =========================================== */
+
+static void process_etds(struct usb_hcd *hcd, struct imx21 *imx21, int sof)
+{
+       int etd_num;
+       int enable_sof_int = 0;
+       unsigned long flags;
+
+       spin_lock_irqsave(&imx21->lock, flags);
+
+       for (etd_num = 0; etd_num < USB_NUM_ETD; etd_num++) {
+               u32 etd_mask = 1 << etd_num;
+               u32 enabled = readl(imx21->regs + USBH_ETDENSET) & etd_mask;
+               u32 done = readl(imx21->regs + USBH_ETDDONESTAT) & etd_mask;
+               struct etd_priv *etd = &imx21->etd[etd_num];
+
+
+               if (done) {
+                       DEBUG_LOG_FRAME(imx21, etd, last_int);
+               } else {
+/*
+ * Kludge warning!
+ *
+ * When multiple transfers are using the bus we sometimes get into a state
+ * where the transfer has completed (the CC field of the ETD is != 0x0F),
+ * the ETD has self disabled but the ETDDONESTAT flag is not set
+ * (and hence no interrupt occurs).
+ * This causes the transfer in question to hang.
+ * The kludge below checks for this condition at each SOF and processes any
+ * blocked ETDs (after an arbitrary 10 frame wait)
+ *
+ * With a single active transfer the usbtest test suite will run for days
+ * without the kludge.
+ * With other bus activity (eg mass storage) even just test1 will hang without
+ * the kludge.
+ */
+                       u32 dword0;
+                       int cc;
+
+                       if (etd->active_count && !enabled) /* suspicious... */
+                               enable_sof_int = 1;
+
+                       if (!sof || enabled || !etd->active_count)
+                               continue;
+
+                       cc = etd_readl(imx21, etd_num, 2) >> DW2_COMPCODE;
+                       if (cc == TD_NOTACCESSED)
+                               continue;
+
+                       if (++etd->active_count < 10)
+                               continue;
+
+                       dword0 = etd_readl(imx21, etd_num, 0);
+                       dev_dbg(imx21->dev,
+                               "unblock ETD %d dev=0x%X ep=0x%X cc=0x%02X!\n",
+                               etd_num, dword0 & 0x7F,
+                               (dword0 >> DW0_ENDPNT) & 0x0F,
+                               cc);
+
+#ifdef DEBUG
+                       dev_dbg(imx21->dev,
+                               "frame: act=%d disact=%d"
+                               " int=%d req=%d cur=%d\n",
+                               etd->activated_frame,
+                               etd->disactivated_frame,
+                               etd->last_int_frame,
+                               etd->last_req_frame,
+                               readl(imx21->regs + USBH_FRMNUB));
+                       imx21->debug_unblocks++;
+#endif
+                       etd->active_count = 0;
+/* End of kludge */
+               }
+
+               if (etd->ep == NULL || etd->urb == NULL) {
+                       dev_dbg(imx21->dev,
+                               "Interrupt for unexpected etd %d"
+                               " ep=%p urb=%p\n",
+                               etd_num, etd->ep, etd->urb);
+                       disactivate_etd(imx21, etd_num);
+                       continue;
+               }
+
+               if (usb_pipeisoc(etd->urb->pipe))
+                       isoc_etd_done(hcd, etd_num);
+               else
+                       nonisoc_etd_done(hcd, etd_num);
+       }
+
+       /* only enable SOF interrupt if it may be needed for the kludge */
+       if (enable_sof_int)
+               set_register_bits(imx21, USBH_SYSIEN, USBH_SYSIEN_SOFINT);
+       else
+               clear_register_bits(imx21, USBH_SYSIEN, USBH_SYSIEN_SOFINT);
+
+
+       spin_unlock_irqrestore(&imx21->lock, flags);
+}
+
+static irqreturn_t imx21_irq(struct usb_hcd *hcd)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       u32 ints = readl(imx21->regs + USBH_SYSISR);
+
+       if (ints & USBH_SYSIEN_HERRINT)
+               dev_dbg(imx21->dev, "Scheduling error\n");
+
+       if (ints & USBH_SYSIEN_SORINT)
+               dev_dbg(imx21->dev, "Scheduling overrun\n");
+
+       if (ints & (USBH_SYSISR_DONEINT | USBH_SYSISR_SOFINT))
+               process_etds(hcd, imx21, ints & USBH_SYSISR_SOFINT);
+
+       writel(ints, imx21->regs + USBH_SYSISR);
+       return IRQ_HANDLED;
+}
+
+static void imx21_hc_endpoint_disable(struct usb_hcd *hcd,
+                                     struct usb_host_endpoint *ep)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       unsigned long flags;
+       struct ep_priv *ep_priv;
+       int i;
+
+       if (ep == NULL)
+               return;
+
+       spin_lock_irqsave(&imx21->lock, flags);
+       ep_priv = ep->hcpriv;
+       dev_vdbg(imx21->dev, "disable ep=%p, ep->hcpriv=%p\n", ep, ep_priv);
+
+       if (!list_empty(&ep->urb_list))
+               dev_dbg(imx21->dev, "ep's URB list is not empty\n");
+
+       if (ep_priv != NULL) {
+               for (i = 0; i < NUM_ISO_ETDS; i++) {
+                       if (ep_priv->etd[i] > -1)
+                               dev_dbg(imx21->dev, "free etd %d for disable\n",
+                                       ep_priv->etd[i]);
+
+                       free_etd(imx21, ep_priv->etd[i]);
+               }
+               kfree(ep_priv);
+               ep->hcpriv = NULL;
+       }
+
+       for (i = 0; i < USB_NUM_ETD; i++) {
+               if (imx21->etd[i].alloc && imx21->etd[i].ep == ep) {
+                       dev_err(imx21->dev,
+                               "Active etd %d for disabled ep=%p!\n", i, ep);
+                       free_etd(imx21, i);
+               }
+       }
+       free_epdmem(imx21, ep);
+       spin_unlock_irqrestore(&imx21->lock, flags);
+}
+
+/* =========================================== */
+/* Hub handling                                        */
+/* =========================================== */
+
+static int get_hub_descriptor(struct usb_hcd *hcd,
+                             struct usb_hub_descriptor *desc)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       desc->bDescriptorType = USB_DT_HUB; /* HUB descriptor */
+       desc->bHubContrCurrent = 0;
+
+       desc->bNbrPorts = readl(imx21->regs + USBH_ROOTHUBA)
+               & USBH_ROOTHUBA_NDNSTMPRT_MASK;
+       desc->bDescLength = 9;
+       desc->bPwrOn2PwrGood = 0;
+       desc->wHubCharacteristics = (__force __u16) cpu_to_le16(
+               HUB_CHAR_NO_LPSM |      /* No power switching */
+               HUB_CHAR_NO_OCPM);      /* No over current protection */
+
+       desc->u.hs.DeviceRemovable[0] = 1 << 1;
+       desc->u.hs.DeviceRemovable[1] = ~0;
+       return 0;
+}
+
+static int imx21_hc_hub_status_data(struct usb_hcd *hcd, char *buf)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       int ports;
+       int changed = 0;
+       int i;
+       unsigned long flags;
+
+       spin_lock_irqsave(&imx21->lock, flags);
+       ports = readl(imx21->regs + USBH_ROOTHUBA)
+               & USBH_ROOTHUBA_NDNSTMPRT_MASK;
+       if (ports > 7) {
+               ports = 7;
+               dev_err(imx21->dev, "ports %d > 7\n", ports);
+       }
+       for (i = 0; i < ports; i++) {
+               if (readl(imx21->regs + USBH_PORTSTAT(i)) &
+                       (USBH_PORTSTAT_CONNECTSC |
+                       USBH_PORTSTAT_PRTENBLSC |
+                       USBH_PORTSTAT_PRTSTATSC |
+                       USBH_PORTSTAT_OVRCURIC |
+                       USBH_PORTSTAT_PRTRSTSC)) {
+
+                       changed = 1;
+                       buf[0] |= 1 << (i + 1);
+               }
+       }
+       spin_unlock_irqrestore(&imx21->lock, flags);
+
+       if (changed)
+               dev_info(imx21->dev, "Hub status changed\n");
+       return changed;
+}
+
+static int imx21_hc_hub_control(struct usb_hcd *hcd,
+                               u16 typeReq,
+                               u16 wValue, u16 wIndex, char *buf, u16 wLength)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       int rc = 0;
+       u32 status_write = 0;
+
+       switch (typeReq) {
+       case ClearHubFeature:
+               dev_dbg(imx21->dev, "ClearHubFeature\n");
+               switch (wValue) {
+               case C_HUB_OVER_CURRENT:
+                       dev_dbg(imx21->dev, "    OVER_CURRENT\n");
+                       break;
+               case C_HUB_LOCAL_POWER:
+                       dev_dbg(imx21->dev, "    LOCAL_POWER\n");
+                       break;
+               default:
+                       dev_dbg(imx21->dev, "    unknown\n");
+                       rc = -EINVAL;
+                       break;
+               }
+               break;
+
+       case ClearPortFeature:
+               dev_dbg(imx21->dev, "ClearPortFeature\n");
+               switch (wValue) {
+               case USB_PORT_FEAT_ENABLE:
+                       dev_dbg(imx21->dev, "    ENABLE\n");
+                       status_write = USBH_PORTSTAT_CURCONST;
+                       break;
+               case USB_PORT_FEAT_SUSPEND:
+                       dev_dbg(imx21->dev, "    SUSPEND\n");
+                       status_write = USBH_PORTSTAT_PRTOVRCURI;
+                       break;
+               case USB_PORT_FEAT_POWER:
+                       dev_dbg(imx21->dev, "    POWER\n");
+                       status_write = USBH_PORTSTAT_LSDEVCON;
+                       break;
+               case USB_PORT_FEAT_C_ENABLE:
+                       dev_dbg(imx21->dev, "    C_ENABLE\n");
+                       status_write = USBH_PORTSTAT_PRTENBLSC;
+                       break;
+               case USB_PORT_FEAT_C_SUSPEND:
+                       dev_dbg(imx21->dev, "    C_SUSPEND\n");
+                       status_write = USBH_PORTSTAT_PRTSTATSC;
+                       break;
+               case USB_PORT_FEAT_C_CONNECTION:
+                       dev_dbg(imx21->dev, "    C_CONNECTION\n");
+                       status_write = USBH_PORTSTAT_CONNECTSC;
+                       break;
+               case USB_PORT_FEAT_C_OVER_CURRENT:
+                       dev_dbg(imx21->dev, "    C_OVER_CURRENT\n");
+                       status_write = USBH_PORTSTAT_OVRCURIC;
+                       break;
+               case USB_PORT_FEAT_C_RESET:
+                       dev_dbg(imx21->dev, "    C_RESET\n");
+                       status_write = USBH_PORTSTAT_PRTRSTSC;
+                       break;
+               default:
+                       dev_dbg(imx21->dev, "    unknown\n");
+                       rc = -EINVAL;
+                       break;
+               }
+
+               break;
+
+       case GetHubDescriptor:
+               dev_dbg(imx21->dev, "GetHubDescriptor\n");
+               rc = get_hub_descriptor(hcd, (void *)buf);
+               break;
+
+       case GetHubStatus:
+               dev_dbg(imx21->dev, "  GetHubStatus\n");
+               *(__le32 *) buf = 0;
+               break;
+
+       case GetPortStatus:
+               dev_dbg(imx21->dev, "GetPortStatus: port: %d, 0x%x\n",
+                   wIndex, USBH_PORTSTAT(wIndex - 1));
+               *(__le32 *) buf = readl(imx21->regs +
+                       USBH_PORTSTAT(wIndex - 1));
+               break;
+
+       case SetHubFeature:
+               dev_dbg(imx21->dev, "SetHubFeature\n");
+               switch (wValue) {
+               case C_HUB_OVER_CURRENT:
+                       dev_dbg(imx21->dev, "    OVER_CURRENT\n");
+                       break;
+
+               case C_HUB_LOCAL_POWER:
+                       dev_dbg(imx21->dev, "    LOCAL_POWER\n");
+                       break;
+               default:
+                       dev_dbg(imx21->dev, "    unknown\n");
+                       rc = -EINVAL;
+                       break;
+               }
+
+               break;
+
+       case SetPortFeature:
+               dev_dbg(imx21->dev, "SetPortFeature\n");
+               switch (wValue) {
+               case USB_PORT_FEAT_SUSPEND:
+                       dev_dbg(imx21->dev, "    SUSPEND\n");
+                       status_write = USBH_PORTSTAT_PRTSUSPST;
+                       break;
+               case USB_PORT_FEAT_POWER:
+                       dev_dbg(imx21->dev, "    POWER\n");
+                       status_write = USBH_PORTSTAT_PRTPWRST;
+                       break;
+               case USB_PORT_FEAT_RESET:
+                       dev_dbg(imx21->dev, "    RESET\n");
+                       status_write = USBH_PORTSTAT_PRTRSTST;
+                       break;
+               default:
+                       dev_dbg(imx21->dev, "    unknown\n");
+                       rc = -EINVAL;
+                       break;
+               }
+               break;
+
+       default:
+               dev_dbg(imx21->dev, "  unknown\n");
+               rc = -EINVAL;
+               break;
+       }
+
+       if (status_write)
+               writel(status_write, imx21->regs + USBH_PORTSTAT(wIndex - 1));
+       return rc;
+}
+
+/* =========================================== */
+/* Host controller management                  */
+/* =========================================== */
+
+static int imx21_hc_reset(struct usb_hcd *hcd)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       unsigned long timeout;
+       unsigned long flags;
+
+       spin_lock_irqsave(&imx21->lock, flags);
+
+       /* Reset the Host controller modules */
+       writel(USBOTG_RST_RSTCTRL | USBOTG_RST_RSTRH |
+               USBOTG_RST_RSTHSIE | USBOTG_RST_RSTHC,
+               imx21->regs + USBOTG_RST_CTRL);
+
+       /* Wait for reset to finish */
+       timeout = jiffies + HZ;
+       while (readl(imx21->regs + USBOTG_RST_CTRL) != 0) {
+               if (time_after(jiffies, timeout)) {
+                       spin_unlock_irqrestore(&imx21->lock, flags);
+                       dev_err(imx21->dev, "timeout waiting for reset\n");
+                       return -ETIMEDOUT;
+               }
+               spin_unlock_irq(&imx21->lock);
+               schedule_timeout_uninterruptible(1);
+               spin_lock_irq(&imx21->lock);
+       }
+       spin_unlock_irqrestore(&imx21->lock, flags);
+       return 0;
+}
+
+static int imx21_hc_start(struct usb_hcd *hcd)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       unsigned long flags;
+       int i, j;
+       u32 hw_mode = USBOTG_HWMODE_CRECFG_HOST;
+       u32 usb_control = 0;
+
+       hw_mode |= ((imx21->pdata->host_xcvr << USBOTG_HWMODE_HOSTXCVR_SHIFT) &
+                       USBOTG_HWMODE_HOSTXCVR_MASK);
+       hw_mode |= ((imx21->pdata->otg_xcvr << USBOTG_HWMODE_OTGXCVR_SHIFT) &
+                       USBOTG_HWMODE_OTGXCVR_MASK);
+
+       if (imx21->pdata->host1_txenoe)
+               usb_control |= USBCTRL_HOST1_TXEN_OE;
+
+       if (!imx21->pdata->host1_xcverless)
+               usb_control |= USBCTRL_HOST1_BYP_TLL;
+
+       if (imx21->pdata->otg_ext_xcvr)
+               usb_control |= USBCTRL_OTC_RCV_RXDP;
+
+
+       spin_lock_irqsave(&imx21->lock, flags);
+
+       writel((USBOTG_CLK_CTRL_HST | USBOTG_CLK_CTRL_MAIN),
+               imx21->regs + USBOTG_CLK_CTRL);
+       writel(hw_mode, imx21->regs + USBOTG_HWMODE);
+       writel(usb_control, imx21->regs + USBCTRL);
+       writel(USB_MISCCONTROL_SKPRTRY  | USB_MISCCONTROL_ARBMODE,
+               imx21->regs + USB_MISCCONTROL);
+
+       /* Clear the ETDs */
+       for (i = 0; i < USB_NUM_ETD; i++)
+               for (j = 0; j < 4; j++)
+                       etd_writel(imx21, i, j, 0);
+
+       /* Take the HC out of reset */
+       writel(USBH_HOST_CTRL_HCUSBSTE_OPERATIONAL | USBH_HOST_CTRL_CTLBLKSR_1,
+               imx21->regs + USBH_HOST_CTRL);
+
+       /* Enable ports */
+       if (imx21->pdata->enable_otg_host)
+               writel(USBH_PORTSTAT_PRTPWRST | USBH_PORTSTAT_PRTENABST,
+                       imx21->regs + USBH_PORTSTAT(0));
+
+       if (imx21->pdata->enable_host1)
+               writel(USBH_PORTSTAT_PRTPWRST | USBH_PORTSTAT_PRTENABST,
+                       imx21->regs + USBH_PORTSTAT(1));
+
+       if (imx21->pdata->enable_host2)
+               writel(USBH_PORTSTAT_PRTPWRST | USBH_PORTSTAT_PRTENABST,
+                       imx21->regs + USBH_PORTSTAT(2));
+
+
+       hcd->state = HC_STATE_RUNNING;
+
+       /* Enable host controller interrupts */
+       set_register_bits(imx21, USBH_SYSIEN,
+               USBH_SYSIEN_HERRINT |
+               USBH_SYSIEN_DONEINT | USBH_SYSIEN_SORINT);
+       set_register_bits(imx21, USBOTG_CINT_STEN, USBOTG_HCINT);
+
+       spin_unlock_irqrestore(&imx21->lock, flags);
+
+       return 0;
+}
+
+static void imx21_hc_stop(struct usb_hcd *hcd)
+{
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       unsigned long flags;
+
+       spin_lock_irqsave(&imx21->lock, flags);
+
+       writel(0, imx21->regs + USBH_SYSIEN);
+       clear_register_bits(imx21, USBOTG_CINT_STEN, USBOTG_HCINT);
+       clear_register_bits(imx21, USBOTG_CLK_CTRL_HST | USBOTG_CLK_CTRL_MAIN,
+                                       USBOTG_CLK_CTRL);
+       spin_unlock_irqrestore(&imx21->lock, flags);
+}
+
+/* =========================================== */
+/* Driver glue                                 */
+/* =========================================== */
+
+static struct hc_driver imx21_hc_driver = {
+       .description = hcd_name,
+       .product_desc = "IMX21 USB Host Controller",
+       .hcd_priv_size = sizeof(struct imx21),
+
+       .flags = HCD_USB11,
+       .irq = imx21_irq,
+
+       .reset = imx21_hc_reset,
+       .start = imx21_hc_start,
+       .stop = imx21_hc_stop,
+
+       /* I/O requests */
+       .urb_enqueue = imx21_hc_urb_enqueue,
+       .urb_dequeue = imx21_hc_urb_dequeue,
+       .endpoint_disable = imx21_hc_endpoint_disable,
+
+       /* scheduling support */
+       .get_frame_number = imx21_hc_get_frame,
+
+       /* Root hub support */
+       .hub_status_data = imx21_hc_hub_status_data,
+       .hub_control = imx21_hc_hub_control,
+
+};
+
+static struct mx21_usbh_platform_data default_pdata = {
+       .host_xcvr = MX21_USBXCVR_TXDIF_RXDIF,
+       .otg_xcvr = MX21_USBXCVR_TXDIF_RXDIF,
+       .enable_host1 = 1,
+       .enable_host2 = 1,
+       .enable_otg_host = 1,
+
+};
+
+static int imx21_remove(struct platform_device *pdev)
+{
+       struct usb_hcd *hcd = platform_get_drvdata(pdev);
+       struct imx21 *imx21 = hcd_to_imx21(hcd);
+       struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+       remove_debug_files(imx21);
+       usb_remove_hcd(hcd);
+
+       if (res != NULL) {
+               clk_disable_unprepare(imx21->clk);
+               clk_put(imx21->clk);
+               iounmap(imx21->regs);
+               release_mem_region(res->start, resource_size(res));
+       }
+
+       kfree(hcd);
+       return 0;
+}
+
+
+static int imx21_probe(struct platform_device *pdev)
+{
+       struct usb_hcd *hcd;
+       struct imx21 *imx21;
+       struct resource *res;
+       int ret;
+       int irq;
+
+       printk(KERN_INFO "%s\n", imx21_hc_driver.product_desc);
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res)
+               return -ENODEV;
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0)
+               return -ENXIO;
+
+       hcd = usb_create_hcd(&imx21_hc_driver,
+               &pdev->dev, dev_name(&pdev->dev));
+       if (hcd == NULL) {
+               dev_err(&pdev->dev, "Cannot create hcd (%s)\n",
+                   dev_name(&pdev->dev));
+               return -ENOMEM;
+       }
+
+       imx21 = hcd_to_imx21(hcd);
+       imx21->hcd = hcd;
+       imx21->dev = &pdev->dev;
+       imx21->pdata = dev_get_platdata(&pdev->dev);
+       if (!imx21->pdata)
+               imx21->pdata = &default_pdata;
+
+       spin_lock_init(&imx21->lock);
+       INIT_LIST_HEAD(&imx21->dmem_list);
+       INIT_LIST_HEAD(&imx21->queue_for_etd);
+       INIT_LIST_HEAD(&imx21->queue_for_dmem);
+       create_debug_files(imx21);
+
+       res = request_mem_region(res->start, resource_size(res), hcd_name);
+       if (!res) {
+               ret = -EBUSY;
+               goto failed_request_mem;
+       }
+
+       imx21->regs = ioremap(res->start, resource_size(res));
+       if (imx21->regs == NULL) {
+               dev_err(imx21->dev, "Cannot map registers\n");
+               ret = -ENOMEM;
+               goto failed_ioremap;
+       }
+
+       /* Enable clocks source */
+       imx21->clk = clk_get(imx21->dev, NULL);
+       if (IS_ERR(imx21->clk)) {
+               dev_err(imx21->dev, "no clock found\n");
+               ret = PTR_ERR(imx21->clk);
+               goto failed_clock_get;
+       }
+
+       ret = clk_set_rate(imx21->clk, clk_round_rate(imx21->clk, 48000000));
+       if (ret)
+               goto failed_clock_set;
+       ret = clk_prepare_enable(imx21->clk);
+       if (ret)
+               goto failed_clock_enable;
+
+       dev_info(imx21->dev, "Hardware HC revision: 0x%02X\n",
+               (readl(imx21->regs + USBOTG_HWMODE) >> 16) & 0xFF);
+
+       ret = usb_add_hcd(hcd, irq, 0);
+       if (ret != 0) {
+               dev_err(imx21->dev, "usb_add_hcd() returned %d\n", ret);
+               goto failed_add_hcd;
+       }
+       device_wakeup_enable(hcd->self.controller);
+
+       return 0;
+
+failed_add_hcd:
+       clk_disable_unprepare(imx21->clk);
+failed_clock_enable:
+failed_clock_set:
+       clk_put(imx21->clk);
+failed_clock_get:
+       iounmap(imx21->regs);
+failed_ioremap:
+       release_mem_region(res->start, resource_size(res));
+failed_request_mem:
+       remove_debug_files(imx21);
+       usb_put_hcd(hcd);
+       return ret;
+}
+
+static struct platform_driver imx21_hcd_driver = {
+       .driver = {
+                  .name = hcd_name,
+                  },
+       .probe = imx21_probe,
+       .remove = imx21_remove,
+       .suspend = NULL,
+       .resume = NULL,
+};
+
+module_platform_driver(imx21_hcd_driver);
+
+MODULE_DESCRIPTION("i.MX21 USB Host controller");
+MODULE_AUTHOR("Martin Fuzzey");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:imx21-hcd");