This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / drivers / net / wireless / zd1211rw / zd_usb.c
diff --git a/drivers/net/wireless/zd1211rw/zd_usb.c b/drivers/net/wireless/zd1211rw/zd_usb.c
new file mode 100644 (file)
index 0000000..6320984
--- /dev/null
@@ -0,0 +1,1309 @@
+/* zd_usb.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <asm/unaligned.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/firmware.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/skbuff.h>
+#include <linux/usb.h>
+#include <net/ieee80211.h>
+
+#include "zd_def.h"
+#include "zd_netdev.h"
+#include "zd_mac.h"
+#include "zd_usb.h"
+#include "zd_util.h"
+
+static struct usb_device_id usb_ids[] = {
+       /* ZD1211 */
+       { USB_DEVICE(0x0ace, 0x1211), .driver_info = DEVICE_ZD1211 },
+       { USB_DEVICE(0x07b8, 0x6001), .driver_info = DEVICE_ZD1211 },
+       { USB_DEVICE(0x126f, 0xa006), .driver_info = DEVICE_ZD1211 },
+       { USB_DEVICE(0x6891, 0xa727), .driver_info = DEVICE_ZD1211 },
+       { USB_DEVICE(0x0df6, 0x9071), .driver_info = DEVICE_ZD1211 },
+       { USB_DEVICE(0x157e, 0x300b), .driver_info = DEVICE_ZD1211 },
+       /* ZD1211B */
+       { USB_DEVICE(0x0ace, 0x1215), .driver_info = DEVICE_ZD1211B },
+       { USB_DEVICE(0x157e, 0x300d), .driver_info = DEVICE_ZD1211B },
+       {}
+};
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("USB driver for devices with the ZD1211 chip.");
+MODULE_AUTHOR("Ulrich Kunitz");
+MODULE_AUTHOR("Daniel Drake");
+MODULE_VERSION("1.0");
+MODULE_DEVICE_TABLE(usb, usb_ids);
+
+#define FW_ZD1211_PREFIX       "zd1211/zd1211_"
+#define FW_ZD1211B_PREFIX      "zd1211/zd1211b_"
+
+/* register address handling */
+
+#ifdef DEBUG
+static int check_addr(struct zd_usb *usb, zd_addr_t addr)
+{
+       u32 base = ZD_ADDR_BASE(addr);
+       u32 offset = ZD_OFFSET(addr);
+
+       if ((u32)addr & ADDR_ZERO_MASK)
+               goto invalid_address;
+       switch (base) {
+       case USB_BASE:
+               break;
+       case CR_BASE:
+               if (offset > CR_MAX_OFFSET) {
+                       dev_dbg(zd_usb_dev(usb),
+                               "CR offset %#010x larger than"
+                               " CR_MAX_OFFSET %#10x\n",
+                               offset, CR_MAX_OFFSET);
+                       goto invalid_address;
+               }
+               if (offset & 1) {
+                       dev_dbg(zd_usb_dev(usb),
+                               "CR offset %#010x is not a multiple of 2\n",
+                               offset);
+                       goto invalid_address;
+               }
+               break;
+       case E2P_BASE:
+               if (offset > E2P_MAX_OFFSET) {
+                       dev_dbg(zd_usb_dev(usb),
+                               "E2P offset %#010x larger than"
+                               " E2P_MAX_OFFSET %#010x\n",
+                               offset, E2P_MAX_OFFSET);
+                       goto invalid_address;
+               }
+               break;
+       case FW_BASE:
+               if (!usb->fw_base_offset) {
+                       dev_dbg(zd_usb_dev(usb),
+                              "ERROR: fw base offset has not been set\n");
+                       return -EAGAIN;
+               }
+               if (offset > FW_MAX_OFFSET) {
+                       dev_dbg(zd_usb_dev(usb),
+                               "FW offset %#10x is larger than"
+                               " FW_MAX_OFFSET %#010x\n",
+                               offset, FW_MAX_OFFSET);
+                       goto invalid_address;
+               }
+               break;
+       default:
+               dev_dbg(zd_usb_dev(usb),
+                       "address has unsupported base %#010x\n", addr);
+               goto invalid_address;
+       }
+
+       return 0;
+invalid_address:
+       dev_dbg(zd_usb_dev(usb),
+               "ERROR: invalid address: %#010x\n", addr);
+       return -EINVAL;
+}
+#endif /* DEBUG */
+
+static u16 usb_addr(struct zd_usb *usb, zd_addr_t addr)
+{
+       u32 base;
+       u16 offset;
+
+       base = ZD_ADDR_BASE(addr);
+       offset = ZD_OFFSET(addr);
+
+       ZD_ASSERT(check_addr(usb, addr) == 0);
+
+       switch (base) {
+       case CR_BASE:
+               offset += CR_BASE_OFFSET;
+               break;
+       case E2P_BASE:
+               offset += E2P_BASE_OFFSET;
+               break;
+       case FW_BASE:
+               offset += usb->fw_base_offset;
+               break;
+       }
+
+       return offset;
+}
+
+/* USB device initialization */
+
+static int request_fw_file(
+       const struct firmware **fw, const char *name, struct device *device)
+{
+       int r;
+
+       dev_dbg_f(device, "fw name %s\n", name);
+
+       r = request_firmware(fw, name, device);
+       if (r)
+               dev_err(device,
+                      "Could not load firmware file %s. Error number %d\n",
+                      name, r);
+       return r;
+}
+
+static inline u16 get_bcdDevice(const struct usb_device *udev)
+{
+       return le16_to_cpu(udev->descriptor.bcdDevice);
+}
+
+enum upload_code_flags {
+       REBOOT = 1,
+};
+
+/* Ensures that MAX_TRANSFER_SIZE is even. */
+#define MAX_TRANSFER_SIZE (USB_MAX_TRANSFER_SIZE & ~1)
+
+static int upload_code(struct usb_device *udev,
+       const u8 *data, size_t size, u16 code_offset, int flags)
+{
+       u8 *p;
+       int r;
+
+       /* USB request blocks need "kmalloced" buffers.
+        */
+       p = kmalloc(MAX_TRANSFER_SIZE, GFP_KERNEL);
+       if (!p) {
+               dev_err(&udev->dev, "out of memory\n");
+               r = -ENOMEM;
+               goto error;
+       }
+
+       size &= ~1;
+       while (size > 0) {
+               size_t transfer_size = size <= MAX_TRANSFER_SIZE ?
+                       size : MAX_TRANSFER_SIZE;
+
+               dev_dbg_f(&udev->dev, "transfer size %zu\n", transfer_size);
+
+               memcpy(p, data, transfer_size);
+               r = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+                       USB_REQ_FIRMWARE_DOWNLOAD,
+                       USB_DIR_OUT | USB_TYPE_VENDOR,
+                       code_offset, 0, p, transfer_size, 1000 /* ms */);
+               if (r < 0) {
+                       dev_err(&udev->dev,
+                              "USB control request for firmware upload"
+                              " failed. Error number %d\n", r);
+                       goto error;
+               }
+               transfer_size = r & ~1;
+
+               size -= transfer_size;
+               data += transfer_size;
+               code_offset += transfer_size/sizeof(u16);
+       }
+
+       if (flags & REBOOT) {
+               u8 ret;
+
+               r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
+                       USB_REQ_FIRMWARE_CONFIRM,
+                       USB_DIR_IN | USB_TYPE_VENDOR,
+                       0, 0, &ret, sizeof(ret), 5000 /* ms */);
+               if (r != sizeof(ret)) {
+                       dev_err(&udev->dev,
+                               "control request firmeware confirmation failed."
+                               " Return value %d\n", r);
+                       if (r >= 0)
+                               r = -ENODEV;
+                       goto error;
+               }
+               if (ret & 0x80) {
+                       dev_err(&udev->dev,
+                               "Internal error while downloading."
+                               " Firmware confirm return value %#04x\n",
+                               (unsigned int)ret);
+                       r = -ENODEV;
+                       goto error;
+               }
+               dev_dbg_f(&udev->dev, "firmware confirm return value %#04x\n",
+                       (unsigned int)ret);
+       }
+
+       r = 0;
+error:
+       kfree(p);
+       return r;
+}
+
+static u16 get_word(const void *data, u16 offset)
+{
+       const __le16 *p = data;
+       return le16_to_cpu(p[offset]);
+}
+
+static char *get_fw_name(char *buffer, size_t size, u8 device_type,
+                      const char* postfix)
+{
+       scnprintf(buffer, size, "%s%s",
+               device_type == DEVICE_ZD1211B ?
+                       FW_ZD1211B_PREFIX : FW_ZD1211_PREFIX,
+               postfix);
+       return buffer;
+}
+
+static int upload_firmware(struct usb_device *udev, u8 device_type)
+{
+       int r;
+       u16 fw_bcdDevice;
+       u16 bcdDevice;
+       const struct firmware *ub_fw = NULL;
+       const struct firmware *uph_fw = NULL;
+       char fw_name[128];
+
+       bcdDevice = get_bcdDevice(udev);
+
+       r = request_fw_file(&ub_fw,
+               get_fw_name(fw_name, sizeof(fw_name), device_type,  "ub"),
+               &udev->dev);
+       if (r)
+               goto error;
+
+       fw_bcdDevice = get_word(ub_fw->data, EEPROM_REGS_OFFSET);
+
+       /* FIXME: do we have any reason to perform the kludge that the vendor
+        * driver does when there is a version mismatch? (their driver uploads
+        * different firmwares and stuff)
+        */
+       if (fw_bcdDevice != bcdDevice) {
+               dev_info(&udev->dev,
+                       "firmware device id %#06x and actual device id "
+                       "%#06x differ, continuing anyway\n",
+                       fw_bcdDevice, bcdDevice);
+       } else {
+               dev_dbg_f(&udev->dev,
+                       "firmware device id %#06x is equal to the "
+                       "actual device id\n", fw_bcdDevice);
+       }
+
+
+       r = request_fw_file(&uph_fw,
+               get_fw_name(fw_name, sizeof(fw_name), device_type, "uphr"),
+               &udev->dev);
+       if (r)
+               goto error;
+
+       r = upload_code(udev, uph_fw->data, uph_fw->size, FW_START_OFFSET,
+                       REBOOT);
+       if (r) {
+               dev_err(&udev->dev,
+                       "Could not upload firmware code uph. Error number %d\n",
+                       r);
+       }
+
+       /* FALL-THROUGH */
+error:
+       release_firmware(ub_fw);
+       release_firmware(uph_fw);
+       return r;
+}
+
+static void disable_read_regs_int(struct zd_usb *usb)
+{
+       struct zd_usb_interrupt *intr = &usb->intr;
+
+       spin_lock(&intr->lock);
+       intr->read_regs_enabled = 0;
+       spin_unlock(&intr->lock);
+}
+
+#define urb_dev(urb) (&(urb)->dev->dev)
+
+static inline void handle_regs_int(struct urb *urb)
+{
+       struct zd_usb *usb = urb->context;
+       struct zd_usb_interrupt *intr = &usb->intr;
+       int len;
+
+       ZD_ASSERT(in_interrupt());
+       spin_lock(&intr->lock);
+
+       if (intr->read_regs_enabled) {
+               intr->read_regs.length = len = urb->actual_length;
+
+               if (len > sizeof(intr->read_regs.buffer))
+                       len = sizeof(intr->read_regs.buffer);
+               memcpy(intr->read_regs.buffer, urb->transfer_buffer, len);
+               intr->read_regs_enabled = 0;
+               complete(&intr->read_regs.completion);
+               goto out;
+       }
+
+       dev_dbg_f(urb_dev(urb), "regs interrupt ignored\n");
+out:
+       spin_unlock(&intr->lock);
+}
+
+static inline void handle_retry_failed_int(struct urb *urb)
+{
+       dev_dbg_f(urb_dev(urb), "retry failed interrupt\n");
+}
+
+
+static void int_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
+{
+       int r;
+       struct usb_int_header *hdr;
+
+       switch (urb->status) {
+       case 0:
+               break;
+       case -ESHUTDOWN:
+       case -EINVAL:
+       case -ENODEV:
+       case -ENOENT:
+       case -ECONNRESET:
+       case -EPIPE:
+               goto kfree;
+       default:
+               goto resubmit;
+       }
+
+       if (urb->actual_length < sizeof(hdr)) {
+               dev_dbg_f(urb_dev(urb), "error: urb %p to small\n", urb);
+               goto resubmit;
+       }
+
+       hdr = urb->transfer_buffer;
+       if (hdr->type != USB_INT_TYPE) {
+               dev_dbg_f(urb_dev(urb), "error: urb %p wrong type\n", urb);
+               goto resubmit;
+       }
+
+       switch (hdr->id) {
+       case USB_INT_ID_REGS:
+               handle_regs_int(urb);
+               break;
+       case USB_INT_ID_RETRY_FAILED:
+               handle_retry_failed_int(urb);
+               break;
+       default:
+               dev_dbg_f(urb_dev(urb), "error: urb %p unknown id %x\n", urb,
+                       (unsigned int)hdr->id);
+               goto resubmit;
+       }
+
+resubmit:
+       r = usb_submit_urb(urb, GFP_ATOMIC);
+       if (r) {
+               dev_dbg_f(urb_dev(urb), "resubmit urb %p\n", urb);
+               goto kfree;
+       }
+       return;
+kfree:
+       kfree(urb->transfer_buffer);
+}
+
+static inline int int_urb_interval(struct usb_device *udev)
+{
+       switch (udev->speed) {
+       case USB_SPEED_HIGH:
+               return 4;
+       case USB_SPEED_LOW:
+               return 10;
+       case USB_SPEED_FULL:
+       default:
+               return 1;
+       }
+}
+
+static inline int usb_int_enabled(struct zd_usb *usb)
+{
+       unsigned long flags;
+       struct zd_usb_interrupt *intr = &usb->intr;
+       struct urb *urb;
+
+       spin_lock_irqsave(&intr->lock, flags);
+       urb = intr->urb;
+       spin_unlock_irqrestore(&intr->lock, flags);
+       return urb != NULL;
+}
+
+int zd_usb_enable_int(struct zd_usb *usb)
+{
+       int r;
+       struct usb_device *udev;
+       struct zd_usb_interrupt *intr = &usb->intr;
+       void *transfer_buffer = NULL;
+       struct urb *urb;
+
+       dev_dbg_f(zd_usb_dev(usb), "\n");
+
+       urb = usb_alloc_urb(0, GFP_NOFS);
+       if (!urb) {
+               r = -ENOMEM;
+               goto out;
+       }
+
+       ZD_ASSERT(!irqs_disabled());
+       spin_lock_irq(&intr->lock);
+       if (intr->urb) {
+               spin_unlock_irq(&intr->lock);
+               r = 0;
+               goto error_free_urb;
+       }
+       intr->urb = urb;
+       spin_unlock_irq(&intr->lock);
+
+       /* TODO: make it a DMA buffer */
+       r = -ENOMEM;
+       transfer_buffer = kmalloc(USB_MAX_EP_INT_BUFFER, GFP_NOFS);
+       if (!transfer_buffer) {
+               dev_dbg_f(zd_usb_dev(usb),
+                       "couldn't allocate transfer_buffer\n");
+               goto error_set_urb_null;
+       }
+
+       udev = zd_usb_to_usbdev(usb);
+       usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, EP_INT_IN),
+                        transfer_buffer, USB_MAX_EP_INT_BUFFER,
+                        int_urb_complete, usb,
+                        intr->interval);
+
+       dev_dbg_f(zd_usb_dev(usb), "submit urb %p\n", intr->urb);
+       r = usb_submit_urb(urb, GFP_NOFS);
+       if (r) {
+               dev_dbg_f(zd_usb_dev(usb),
+                        "Couldn't submit urb. Error number %d\n", r);
+               goto error;
+       }
+
+       return 0;
+error:
+       kfree(transfer_buffer);
+error_set_urb_null:
+       spin_lock_irq(&intr->lock);
+       intr->urb = NULL;
+       spin_unlock_irq(&intr->lock);
+error_free_urb:
+       usb_free_urb(urb);
+out:
+       return r;
+}
+
+void zd_usb_disable_int(struct zd_usb *usb)
+{
+       unsigned long flags;
+       struct zd_usb_interrupt *intr = &usb->intr;
+       struct urb *urb;
+
+       spin_lock_irqsave(&intr->lock, flags);
+       urb = intr->urb;
+       if (!urb) {
+               spin_unlock_irqrestore(&intr->lock, flags);
+               return;
+       }
+       intr->urb = NULL;
+       spin_unlock_irqrestore(&intr->lock, flags);
+
+       usb_kill_urb(urb);
+       dev_dbg_f(zd_usb_dev(usb), "urb %p killed\n", urb);
+       usb_free_urb(urb);
+}
+
+static void handle_rx_packet(struct zd_usb *usb, const u8 *buffer,
+                            unsigned int length)
+{
+       int i;
+       struct zd_mac *mac = zd_usb_to_mac(usb);
+       const struct rx_length_info *length_info;
+
+       if (length < sizeof(struct rx_length_info)) {
+               /* It's not a complete packet anyhow. */
+               return;
+       }
+       length_info = (struct rx_length_info *)
+               (buffer + length - sizeof(struct rx_length_info));
+
+       /* It might be that three frames are merged into a single URB
+        * transaction. We have to check for the length info tag.
+        *
+        * While testing we discovered that length_info might be unaligned,
+        * because if USB transactions are merged, the last packet will not
+        * be padded. Unaligned access might also happen if the length_info
+        * structure is not present.
+        */
+       if (get_unaligned(&length_info->tag) == cpu_to_le16(RX_LENGTH_INFO_TAG))
+       {
+               unsigned int l, k, n;
+               for (i = 0, l = 0;; i++) {
+                       k = le16_to_cpu(get_unaligned(&length_info->length[i]));
+                       n = l+k;
+                       if (n > length)
+                               return;
+                       zd_mac_rx(mac, buffer+l, k);
+                       if (i >= 2)
+                               return;
+                       l = (n+3) & ~3;
+               }
+       } else {
+               zd_mac_rx(mac, buffer, length);
+       }
+}
+
+static void rx_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
+{
+       struct zd_usb *usb;
+       struct zd_usb_rx *rx;
+       const u8 *buffer;
+       unsigned int length;
+
+       switch (urb->status) {
+       case 0:
+               break;
+       case -ESHUTDOWN:
+       case -EINVAL:
+       case -ENODEV:
+       case -ENOENT:
+       case -ECONNRESET:
+       case -EPIPE:
+               return;
+       default:
+               dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
+               goto resubmit;
+       }
+
+       buffer = urb->transfer_buffer;
+       length = urb->actual_length;
+       usb = urb->context;
+       rx = &usb->rx;
+
+       if (length%rx->usb_packet_size > rx->usb_packet_size-4) {
+               /* If there is an old first fragment, we don't care. */
+               dev_dbg_f(urb_dev(urb), "*** first fragment ***\n");
+               ZD_ASSERT(length <= ARRAY_SIZE(rx->fragment));
+               spin_lock(&rx->lock);
+               memcpy(rx->fragment, buffer, length);
+               rx->fragment_length = length;
+               spin_unlock(&rx->lock);
+               goto resubmit;
+       }
+
+       spin_lock(&rx->lock);
+       if (rx->fragment_length > 0) {
+               /* We are on a second fragment, we believe */
+               ZD_ASSERT(length + rx->fragment_length <=
+                         ARRAY_SIZE(rx->fragment));
+               dev_dbg_f(urb_dev(urb), "*** second fragment ***\n");
+               memcpy(rx->fragment+rx->fragment_length, buffer, length);
+               handle_rx_packet(usb, rx->fragment,
+                                rx->fragment_length + length);
+               rx->fragment_length = 0;
+               spin_unlock(&rx->lock);
+       } else {
+               spin_unlock(&rx->lock);
+               handle_rx_packet(usb, buffer, length);
+       }
+
+resubmit:
+       usb_submit_urb(urb, GFP_ATOMIC);
+}
+
+struct urb *alloc_urb(struct zd_usb *usb)
+{
+       struct usb_device *udev = zd_usb_to_usbdev(usb);
+       struct urb *urb;
+       void *buffer;
+
+       urb = usb_alloc_urb(0, GFP_NOFS);
+       if (!urb)
+               return NULL;
+       buffer = usb_buffer_alloc(udev, USB_MAX_RX_SIZE, GFP_NOFS,
+                                 &urb->transfer_dma);
+       if (!buffer) {
+               usb_free_urb(urb);
+               return NULL;
+       }
+
+       usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_DATA_IN),
+                         buffer, USB_MAX_RX_SIZE,
+                         rx_urb_complete, usb);
+       urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+       return urb;
+}
+
+void free_urb(struct urb *urb)
+{
+       if (!urb)
+               return;
+       usb_buffer_free(urb->dev, urb->transfer_buffer_length,
+                       urb->transfer_buffer, urb->transfer_dma);
+       usb_free_urb(urb);
+}
+
+int zd_usb_enable_rx(struct zd_usb *usb)
+{
+       int i, r;
+       struct zd_usb_rx *rx = &usb->rx;
+       struct urb **urbs;
+
+       dev_dbg_f(zd_usb_dev(usb), "\n");
+
+       r = -ENOMEM;
+       urbs = kcalloc(URBS_COUNT, sizeof(struct urb *), GFP_NOFS);
+       if (!urbs)
+               goto error;
+       for (i = 0; i < URBS_COUNT; i++) {
+               urbs[i] = alloc_urb(usb);
+               if (!urbs[i])
+                       goto error;
+       }
+
+       ZD_ASSERT(!irqs_disabled());
+       spin_lock_irq(&rx->lock);
+       if (rx->urbs) {
+               spin_unlock_irq(&rx->lock);
+               r = 0;
+               goto error;
+       }
+       rx->urbs = urbs;
+       rx->urbs_count = URBS_COUNT;
+       spin_unlock_irq(&rx->lock);
+
+       for (i = 0; i < URBS_COUNT; i++) {
+               r = usb_submit_urb(urbs[i], GFP_NOFS);
+               if (r)
+                       goto error_submit;
+       }
+
+       return 0;
+error_submit:
+       for (i = 0; i < URBS_COUNT; i++) {
+               usb_kill_urb(urbs[i]);
+       }
+       spin_lock_irq(&rx->lock);
+       rx->urbs = NULL;
+       rx->urbs_count = 0;
+       spin_unlock_irq(&rx->lock);
+error:
+       if (urbs) {
+               for (i = 0; i < URBS_COUNT; i++)
+                       free_urb(urbs[i]);
+       }
+       return r;
+}
+
+void zd_usb_disable_rx(struct zd_usb *usb)
+{
+       int i;
+       unsigned long flags;
+       struct urb **urbs;
+       unsigned int count;
+       struct zd_usb_rx *rx = &usb->rx;
+
+       spin_lock_irqsave(&rx->lock, flags);
+       urbs = rx->urbs;
+       count = rx->urbs_count;
+       spin_unlock_irqrestore(&rx->lock, flags);
+       if (!urbs)
+               return;
+
+       for (i = 0; i < count; i++) {
+               usb_kill_urb(urbs[i]);
+               free_urb(urbs[i]);
+       }
+       kfree(urbs);
+
+       spin_lock_irqsave(&rx->lock, flags);
+       rx->urbs = NULL;
+       rx->urbs_count = 0;
+       spin_unlock_irqrestore(&rx->lock, flags);
+}
+
+static void tx_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
+{
+       int r;
+
+       switch (urb->status) {
+       case 0:
+               break;
+       case -ESHUTDOWN:
+       case -EINVAL:
+       case -ENODEV:
+       case -ENOENT:
+       case -ECONNRESET:
+       case -EPIPE:
+               dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
+               break;
+       default:
+               dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
+               goto resubmit;
+       }
+free_urb:
+       usb_buffer_free(urb->dev, urb->transfer_buffer_length,
+                       urb->transfer_buffer, urb->transfer_dma);
+       usb_free_urb(urb);
+       return;
+resubmit:
+       r = usb_submit_urb(urb, GFP_ATOMIC);
+       if (r) {
+               dev_dbg_f(urb_dev(urb), "error resubmit urb %p %d\n", urb, r);
+               goto free_urb;
+       }
+}
+
+/* Puts the frame on the USB endpoint. It doesn't wait for
+ * completion. The frame must contain the control set.
+ */
+int zd_usb_tx(struct zd_usb *usb, const u8 *frame, unsigned int length)
+{
+       int r;
+       struct usb_device *udev = zd_usb_to_usbdev(usb);
+       struct urb *urb;
+       void *buffer;
+
+       urb = usb_alloc_urb(0, GFP_ATOMIC);
+       if (!urb) {
+               r = -ENOMEM;
+               goto out;
+       }
+
+       buffer = usb_buffer_alloc(zd_usb_to_usbdev(usb), length, GFP_ATOMIC,
+                                 &urb->transfer_dma);
+       if (!buffer) {
+               r = -ENOMEM;
+               goto error_free_urb;
+       }
+       memcpy(buffer, frame, length);
+
+       usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, EP_DATA_OUT),
+                         buffer, length, tx_urb_complete, NULL);
+       urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+       r = usb_submit_urb(urb, GFP_ATOMIC);
+       if (r)
+               goto error;
+       return 0;
+error:
+       usb_buffer_free(zd_usb_to_usbdev(usb), length, buffer,
+                       urb->transfer_dma);
+error_free_urb:
+       usb_free_urb(urb);
+out:
+       return r;
+}
+
+static inline void init_usb_interrupt(struct zd_usb *usb)
+{
+       struct zd_usb_interrupt *intr = &usb->intr;
+
+       spin_lock_init(&intr->lock);
+       intr->interval = int_urb_interval(zd_usb_to_usbdev(usb));
+       init_completion(&intr->read_regs.completion);
+       intr->read_regs.cr_int_addr = cpu_to_le16(usb_addr(usb, CR_INTERRUPT));
+}
+
+static inline void init_usb_rx(struct zd_usb *usb)
+{
+       struct zd_usb_rx *rx = &usb->rx;
+       spin_lock_init(&rx->lock);
+       if (interface_to_usbdev(usb->intf)->speed == USB_SPEED_HIGH) {
+               rx->usb_packet_size = 512;
+       } else {
+               rx->usb_packet_size = 64;
+       }
+       ZD_ASSERT(rx->fragment_length == 0);
+}
+
+static inline void init_usb_tx(struct zd_usb *usb)
+{
+       /* FIXME: at this point we will allocate a fixed number of urb's for
+        * use in a cyclic scheme */
+}
+
+void zd_usb_init(struct zd_usb *usb, struct net_device *netdev,
+                struct usb_interface *intf)
+{
+       memset(usb, 0, sizeof(*usb));
+       usb->intf = usb_get_intf(intf);
+       usb_set_intfdata(usb->intf, netdev);
+       init_usb_interrupt(usb);
+       init_usb_tx(usb);
+       init_usb_rx(usb);
+}
+
+int zd_usb_init_hw(struct zd_usb *usb)
+{
+       int r;
+       struct zd_chip *chip = zd_usb_to_chip(usb);
+
+       ZD_ASSERT(mutex_is_locked(&chip->mutex));
+       r = zd_ioread16_locked(chip, &usb->fw_base_offset,
+                       USB_REG((u16)FW_BASE_ADDR_OFFSET));
+       if (r)
+               return r;
+       dev_dbg_f(zd_usb_dev(usb), "fw_base_offset: %#06hx\n",
+                usb->fw_base_offset);
+
+       return 0;
+}
+
+void zd_usb_clear(struct zd_usb *usb)
+{
+       usb_set_intfdata(usb->intf, NULL);
+       usb_put_intf(usb->intf);
+       memset(usb, 0, sizeof(*usb));
+       /* FIXME: usb_interrupt, usb_tx, usb_rx? */
+}
+
+static const char *speed(enum usb_device_speed speed)
+{
+       switch (speed) {
+       case USB_SPEED_LOW:
+               return "low";
+       case USB_SPEED_FULL:
+               return "full";
+       case USB_SPEED_HIGH:
+               return "high";
+       default:
+               return "unknown speed";
+       }
+}
+
+static int scnprint_id(struct usb_device *udev, char *buffer, size_t size)
+{
+       return scnprintf(buffer, size, "%04hx:%04hx v%04hx %s",
+               le16_to_cpu(udev->descriptor.idVendor),
+               le16_to_cpu(udev->descriptor.idProduct),
+               get_bcdDevice(udev),
+               speed(udev->speed));
+}
+
+int zd_usb_scnprint_id(struct zd_usb *usb, char *buffer, size_t size)
+{
+       struct usb_device *udev = interface_to_usbdev(usb->intf);
+       return scnprint_id(udev, buffer, size);
+}
+
+#ifdef DEBUG
+static void print_id(struct usb_device *udev)
+{
+       char buffer[40];
+
+       scnprint_id(udev, buffer, sizeof(buffer));
+       buffer[sizeof(buffer)-1] = 0;
+       dev_dbg_f(&udev->dev, "%s\n", buffer);
+}
+#else
+#define print_id(udev) do { } while (0)
+#endif
+
+static int probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+       int r;
+       struct usb_device *udev = interface_to_usbdev(intf);
+       struct net_device *netdev = NULL;
+
+       print_id(udev);
+
+       switch (udev->speed) {
+       case USB_SPEED_LOW:
+       case USB_SPEED_FULL:
+       case USB_SPEED_HIGH:
+               break;
+       default:
+               dev_dbg_f(&intf->dev, "Unknown USB speed\n");
+               r = -ENODEV;
+               goto error;
+       }
+
+       netdev = zd_netdev_alloc(intf);
+       if (netdev == NULL) {
+               r = -ENOMEM;
+               goto error;
+       }
+
+       r = upload_firmware(udev, id->driver_info);
+       if (r) {
+               dev_err(&intf->dev,
+                      "couldn't load firmware. Error number %d\n", r);
+               goto error;
+       }
+
+       r = usb_reset_configuration(udev);
+       if (r) {
+               dev_dbg_f(&intf->dev,
+                       "couldn't reset configuration. Error number %d\n", r);
+               goto error;
+       }
+
+       /* At this point the interrupt endpoint is not generally enabled. We
+        * save the USB bandwidth until the network device is opened. But
+        * notify that the initialization of the MAC will require the
+        * interrupts to be temporary enabled.
+        */
+       r = zd_mac_init_hw(zd_netdev_mac(netdev), id->driver_info);
+       if (r) {
+               dev_dbg_f(&intf->dev,
+                        "couldn't initialize mac. Error number %d\n", r);
+               goto error;
+       }
+
+       r = register_netdev(netdev);
+       if (r) {
+               dev_dbg_f(&intf->dev,
+                        "couldn't register netdev. Error number %d\n", r);
+               goto error;
+       }
+
+       dev_dbg_f(&intf->dev, "successful\n");
+       dev_info(&intf->dev,"%s\n", netdev->name);
+       return 0;
+error:
+       usb_reset_device(interface_to_usbdev(intf));
+       zd_netdev_free(netdev);
+       return r;
+}
+
+static void disconnect(struct usb_interface *intf)
+{
+       struct net_device *netdev = zd_intf_to_netdev(intf);
+       struct zd_mac *mac = zd_netdev_mac(netdev);
+       struct zd_usb *usb = &mac->chip.usb;
+
+       dev_dbg_f(zd_usb_dev(usb), "\n");
+
+       zd_netdev_disconnect(netdev);
+
+       /* Just in case something has gone wrong! */
+       zd_usb_disable_rx(usb);
+       zd_usb_disable_int(usb);
+
+       /* If the disconnect has been caused by a removal of the
+        * driver module, the reset allows reloading of the driver. If the
+        * reset will not be executed here, the upload of the firmware in the
+        * probe function caused by the reloading of the driver will fail.
+        */
+       usb_reset_device(interface_to_usbdev(intf));
+
+       /* If somebody still waits on this lock now, this is an error. */
+       zd_netdev_free(netdev);
+       dev_dbg(&intf->dev, "disconnected\n");
+}
+
+static struct usb_driver driver = {
+       .name           = "zd1211rw",
+       .id_table       = usb_ids,
+       .probe          = probe,
+       .disconnect     = disconnect,
+};
+
+static int __init usb_init(void)
+{
+       int r;
+
+       pr_debug("usb_init()\n");
+
+       r = usb_register(&driver);
+       if (r) {
+               printk(KERN_ERR "usb_register() failed. Error number %d\n", r);
+               return r;
+       }
+
+       pr_debug("zd1211rw initialized\n");
+       return 0;
+}
+
+static void __exit usb_exit(void)
+{
+       pr_debug("usb_exit()\n");
+       usb_deregister(&driver);
+}
+
+module_init(usb_init);
+module_exit(usb_exit);
+
+static int usb_int_regs_length(unsigned int count)
+{
+       return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data);
+}
+
+static void prepare_read_regs_int(struct zd_usb *usb)
+{
+       struct zd_usb_interrupt *intr = &usb->intr;
+
+       spin_lock(&intr->lock);
+       intr->read_regs_enabled = 1;
+       INIT_COMPLETION(intr->read_regs.completion);
+       spin_unlock(&intr->lock);
+}
+
+static int get_results(struct zd_usb *usb, u16 *values,
+                      struct usb_req_read_regs *req, unsigned int count)
+{
+       int r;
+       int i;
+       struct zd_usb_interrupt *intr = &usb->intr;
+       struct read_regs_int *rr = &intr->read_regs;
+       struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
+
+       spin_lock(&intr->lock);
+
+       r = -EIO;
+       /* The created block size seems to be larger than expected.
+        * However results appear to be correct.
+        */
+       if (rr->length < usb_int_regs_length(count)) {
+               dev_dbg_f(zd_usb_dev(usb),
+                        "error: actual length %d less than expected %d\n",
+                        rr->length, usb_int_regs_length(count));
+               goto error_unlock;
+       }
+       if (rr->length > sizeof(rr->buffer)) {
+               dev_dbg_f(zd_usb_dev(usb),
+                        "error: actual length %d exceeds buffer size %zu\n",
+                        rr->length, sizeof(rr->buffer));
+               goto error_unlock;
+       }
+
+       for (i = 0; i < count; i++) {
+               struct reg_data *rd = &regs->regs[i];
+               if (rd->addr != req->addr[i]) {
+                       dev_dbg_f(zd_usb_dev(usb),
+                                "rd[%d] addr %#06hx expected %#06hx\n", i,
+                                le16_to_cpu(rd->addr),
+                                le16_to_cpu(req->addr[i]));
+                       goto error_unlock;
+               }
+               values[i] = le16_to_cpu(rd->value);
+       }
+
+       r = 0;
+error_unlock:
+       spin_unlock(&intr->lock);
+       return r;
+}
+
+int zd_usb_ioread16v(struct zd_usb *usb, u16 *values,
+                    const zd_addr_t *addresses, unsigned int count)
+{
+       int r;
+       int i, req_len, actual_req_len;
+       struct usb_device *udev;
+       struct usb_req_read_regs *req = NULL;
+       unsigned long timeout;
+
+       if (count < 1) {
+               dev_dbg_f(zd_usb_dev(usb), "error: count is zero\n");
+               return -EINVAL;
+       }
+       if (count > USB_MAX_IOREAD16_COUNT) {
+               dev_dbg_f(zd_usb_dev(usb),
+                        "error: count %u exceeds possible max %u\n",
+                        count, USB_MAX_IOREAD16_COUNT);
+               return -EINVAL;
+       }
+       if (in_atomic()) {
+               dev_dbg_f(zd_usb_dev(usb),
+                        "error: io in atomic context not supported\n");
+               return -EWOULDBLOCK;
+       }
+       if (!usb_int_enabled(usb)) {
+                dev_dbg_f(zd_usb_dev(usb),
+                         "error: usb interrupt not enabled\n");
+               return -EWOULDBLOCK;
+       }
+
+       req_len = sizeof(struct usb_req_read_regs) + count * sizeof(__le16);
+       req = kmalloc(req_len, GFP_NOFS);
+       if (!req)
+               return -ENOMEM;
+       req->id = cpu_to_le16(USB_REQ_READ_REGS);
+       for (i = 0; i < count; i++)
+               req->addr[i] = cpu_to_le16(usb_addr(usb, addresses[i]));
+
+       udev = zd_usb_to_usbdev(usb);
+       prepare_read_regs_int(usb);
+       r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
+                        req, req_len, &actual_req_len, 1000 /* ms */);
+       if (r) {
+               dev_dbg_f(zd_usb_dev(usb),
+                       "error in usb_bulk_msg(). Error number %d\n", r);
+               goto error;
+       }
+       if (req_len != actual_req_len) {
+               dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()\n"
+                       " req_len %d != actual_req_len %d\n",
+                       req_len, actual_req_len);
+               r = -EIO;
+               goto error;
+       }
+
+       timeout = wait_for_completion_timeout(&usb->intr.read_regs.completion,
+                                             msecs_to_jiffies(1000));
+       if (!timeout) {
+               disable_read_regs_int(usb);
+               dev_dbg_f(zd_usb_dev(usb), "read timed out\n");
+               r = -ETIMEDOUT;
+               goto error;
+       }
+
+       r = get_results(usb, values, req, count);
+error:
+       kfree(req);
+       return r;
+}
+
+int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
+                     unsigned int count)
+{
+       int r;
+       struct usb_device *udev;
+       struct usb_req_write_regs *req = NULL;
+       int i, req_len, actual_req_len;
+
+       if (count == 0)
+               return 0;
+       if (count > USB_MAX_IOWRITE16_COUNT) {
+               dev_dbg_f(zd_usb_dev(usb),
+                       "error: count %u exceeds possible max %u\n",
+                       count, USB_MAX_IOWRITE16_COUNT);
+               return -EINVAL;
+       }
+       if (in_atomic()) {
+               dev_dbg_f(zd_usb_dev(usb),
+                       "error: io in atomic context not supported\n");
+               return -EWOULDBLOCK;
+       }
+
+       req_len = sizeof(struct usb_req_write_regs) +
+                 count * sizeof(struct reg_data);
+       req = kmalloc(req_len, GFP_NOFS);
+       if (!req)
+               return -ENOMEM;
+
+       req->id = cpu_to_le16(USB_REQ_WRITE_REGS);
+       for (i = 0; i < count; i++) {
+               struct reg_data *rw  = &req->reg_writes[i];
+               rw->addr = cpu_to_le16(usb_addr(usb, ioreqs[i].addr));
+               rw->value = cpu_to_le16(ioreqs[i].value);
+       }
+
+       udev = zd_usb_to_usbdev(usb);
+       r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
+                        req, req_len, &actual_req_len, 1000 /* ms */);
+       if (r) {
+               dev_dbg_f(zd_usb_dev(usb),
+                       "error in usb_bulk_msg(). Error number %d\n", r);
+               goto error;
+       }
+       if (req_len != actual_req_len) {
+               dev_dbg_f(zd_usb_dev(usb),
+                       "error in usb_bulk_msg()"
+                       " req_len %d != actual_req_len %d\n",
+                       req_len, actual_req_len);
+               r = -EIO;
+               goto error;
+       }
+
+       /* FALL-THROUGH with r == 0 */
+error:
+       kfree(req);
+       return r;
+}
+
+int zd_usb_rfwrite(struct zd_usb *usb, u32 value, u8 bits)
+{
+       int r;
+       struct usb_device *udev;
+       struct usb_req_rfwrite *req = NULL;
+       int i, req_len, actual_req_len;
+       u16 bit_value_template;
+
+       if (in_atomic()) {
+               dev_dbg_f(zd_usb_dev(usb),
+                       "error: io in atomic context not supported\n");
+               return -EWOULDBLOCK;
+       }
+       if (bits < USB_MIN_RFWRITE_BIT_COUNT) {
+               dev_dbg_f(zd_usb_dev(usb),
+                       "error: bits %d are smaller than"
+                       " USB_MIN_RFWRITE_BIT_COUNT %d\n",
+                       bits, USB_MIN_RFWRITE_BIT_COUNT);
+               return -EINVAL;
+       }
+       if (bits > USB_MAX_RFWRITE_BIT_COUNT) {
+               dev_dbg_f(zd_usb_dev(usb),
+                       "error: bits %d exceed USB_MAX_RFWRITE_BIT_COUNT %d\n",
+                       bits, USB_MAX_RFWRITE_BIT_COUNT);
+               return -EINVAL;
+       }
+#ifdef DEBUG
+       if (value & (~0UL << bits)) {
+               dev_dbg_f(zd_usb_dev(usb),
+                       "error: value %#09x has bits >= %d set\n",
+                       value, bits);
+               return -EINVAL;
+       }
+#endif /* DEBUG */
+
+       dev_dbg_f(zd_usb_dev(usb), "value %#09x bits %d\n", value, bits);
+
+       r = zd_usb_ioread16(usb, &bit_value_template, CR203);
+       if (r) {
+               dev_dbg_f(zd_usb_dev(usb),
+                       "error %d: Couldn't read CR203\n", r);
+               goto out;
+       }
+       bit_value_template &= ~(RF_IF_LE|RF_CLK|RF_DATA);
+
+       req_len = sizeof(struct usb_req_rfwrite) + bits * sizeof(__le16);
+       req = kmalloc(req_len, GFP_NOFS);
+       if (!req)
+               return -ENOMEM;
+
+       req->id = cpu_to_le16(USB_REQ_WRITE_RF);
+       /* 1: 3683a, but not used in ZYDAS driver */
+       req->value = cpu_to_le16(2);
+       req->bits = cpu_to_le16(bits);
+
+       for (i = 0; i < bits; i++) {
+               u16 bv = bit_value_template;
+               if (value & (1 << (bits-1-i)))
+                       bv |= RF_DATA;
+               req->bit_values[i] = cpu_to_le16(bv);
+       }
+
+       udev = zd_usb_to_usbdev(usb);
+       r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
+                        req, req_len, &actual_req_len, 1000 /* ms */);
+       if (r) {
+               dev_dbg_f(zd_usb_dev(usb),
+                       "error in usb_bulk_msg(). Error number %d\n", r);
+               goto out;
+       }
+       if (req_len != actual_req_len) {
+               dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()"
+                       " req_len %d != actual_req_len %d\n",
+                       req_len, actual_req_len);
+               r = -EIO;
+               goto out;
+       }
+
+       /* FALL-THROUGH with r == 0 */
+out:
+       kfree(req);
+       return r;
+}