drivers/net/wireless/zd1211rw/zd_usb.c

   1 /* zd_usb.c
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write to the Free Software
  15  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  16  */
  17
  18 #include <asm/unaligned.h>
  19 #include <linux/kernel.h>
  20 #include <linux/init.h>
  21 #include <linux/module.h>
  22 #include <linux/firmware.h>
  23 #include <linux/device.h>
  24 #include <linux/errno.h>
  25 #include <linux/skbuff.h>
  26 #include <linux/usb.h>
  27 #include <linux/workqueue.h>
  28 #include <net/ieee80211.h>
  29
  30 #include "zd_def.h"
  31 #include "zd_netdev.h"
  32 #include "zd_mac.h"
  33 #include "zd_usb.h"
  34 #include "zd_util.h"
  35
  36 static struct usb_device_id usb_ids[] = {
  37         /* ZD1211 */
  38         { USB_DEVICE(0x0ace, 0x1211), .driver_info = DEVICE_ZD1211 },
  39         { USB_DEVICE(0x07b8, 0x6001), .driver_info = DEVICE_ZD1211 },
  40         { USB_DEVICE(0x126f, 0xa006), .driver_info = DEVICE_ZD1211 },
  41         { USB_DEVICE(0x6891, 0xa727), .driver_info = DEVICE_ZD1211 },
  42         { USB_DEVICE(0x0df6, 0x9071), .driver_info = DEVICE_ZD1211 },
  43         { USB_DEVICE(0x157e, 0x300b), .driver_info = DEVICE_ZD1211 },
  44         { USB_DEVICE(0x079b, 0x004a), .driver_info = DEVICE_ZD1211 },
  45         { USB_DEVICE(0x1740, 0x2000), .driver_info = DEVICE_ZD1211 },
  46         { USB_DEVICE(0x157e, 0x3204), .driver_info = DEVICE_ZD1211 },
  47         { USB_DEVICE(0x0586, 0x3402), .driver_info = DEVICE_ZD1211 },
  48         { USB_DEVICE(0x0b3b, 0x5630), .driver_info = DEVICE_ZD1211 },
  49         { USB_DEVICE(0x0b05, 0x170c), .driver_info = DEVICE_ZD1211 },
  50         { USB_DEVICE(0x1435, 0x0711), .driver_info = DEVICE_ZD1211 },
  51         { USB_DEVICE(0x0586, 0x3409), .driver_info = DEVICE_ZD1211 },
  52         { USB_DEVICE(0x0b3b, 0x1630), .driver_info = DEVICE_ZD1211 },
  53         { USB_DEVICE(0x0586, 0x3401), .driver_info = DEVICE_ZD1211 },
  54         { USB_DEVICE(0x14ea, 0xab13), .driver_info = DEVICE_ZD1211 },
  55         /* ZD1211B */
  56         { USB_DEVICE(0x0ace, 0x1215), .driver_info = DEVICE_ZD1211B },
  57         { USB_DEVICE(0x157e, 0x300d), .driver_info = DEVICE_ZD1211B },
  58         { USB_DEVICE(0x079b, 0x0062), .driver_info = DEVICE_ZD1211B },
  59         { USB_DEVICE(0x1582, 0x6003), .driver_info = DEVICE_ZD1211B },
  60         { USB_DEVICE(0x050d, 0x705c), .driver_info = DEVICE_ZD1211B },
  61         { USB_DEVICE(0x083a, 0x4505), .driver_info = DEVICE_ZD1211B },
  62         { USB_DEVICE(0x0471, 0x1236), .driver_info = DEVICE_ZD1211B },
  63         { USB_DEVICE(0x13b1, 0x0024), .driver_info = DEVICE_ZD1211B },
  64         { USB_DEVICE(0x0586, 0x340f), .driver_info = DEVICE_ZD1211B },
  65         /* "Driverless" devices that need ejecting */
  66         { USB_DEVICE(0x0ace, 0x2011), .driver_info = DEVICE_INSTALLER },
  67         {}
  68 };
  69
  70 MODULE_LICENSE("GPL");
  71 MODULE_DESCRIPTION("USB driver for devices with the ZD1211 chip.");
  72 MODULE_AUTHOR("Ulrich Kunitz");
  73 MODULE_AUTHOR("Daniel Drake");
  74 MODULE_VERSION("1.0");
  75 MODULE_DEVICE_TABLE(usb, usb_ids);
  76
  77 #define FW_ZD1211_PREFIX        "zd1211/zd1211_"
  78 #define FW_ZD1211B_PREFIX       "zd1211/zd1211b_"
  79
  80 /* USB device initialization */
  81
  82 static int request_fw_file(
  83         const struct firmware **fw, const char *name, struct device *device)
  84 {
  85         int r;
  86
  87         dev_dbg_f(device, "fw name %s\n", name);
  88
  89         r = request_firmware(fw, name, device);
  90         if (r)
  91                 dev_err(device,
  92                        "Could not load firmware file %s. Error number %d\n",
  93                        name, r);
  94         return r;
  95 }
  96
  97 static inline u16 get_bcdDevice(const struct usb_device *udev)
  98 {
  99         return le16_to_cpu(udev->descriptor.bcdDevice);
 100 }
 101
 102 enum upload_code_flags {
 103         REBOOT = 1,
 104 };
 105
 106 /* Ensures that MAX_TRANSFER_SIZE is even. */
 107 #define MAX_TRANSFER_SIZE (USB_MAX_TRANSFER_SIZE & ~1)
 108
 109 static int upload_code(struct usb_device *udev,
 110         const u8 *data, size_t size, u16 code_offset, int flags)
 111 {
 112         u8 *p;
 113         int r;
 114
 115         /* USB request blocks need "kmalloced" buffers.
 116          */
 117         p = kmalloc(MAX_TRANSFER_SIZE, GFP_KERNEL);
 118         if (!p) {
 119                 dev_err(&udev->dev, "out of memory\n");
 120                 r = -ENOMEM;
 121                 goto error;
 122         }
 123
 124         size &= ~1;
 125         while (size > 0) {
 126                 size_t transfer_size = size <= MAX_TRANSFER_SIZE ?
 127                         size : MAX_TRANSFER_SIZE;
 128
 129                 dev_dbg_f(&udev->dev, "transfer size %zu\n", transfer_size);
 130
 131                 memcpy(p, data, transfer_size);
 132                 r = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 133                         USB_REQ_FIRMWARE_DOWNLOAD,
 134                         USB_DIR_OUT | USB_TYPE_VENDOR,
 135                         code_offset, 0, p, transfer_size, 1000 /* ms */);
 136                 if (r < 0) {
 137                         dev_err(&udev->dev,
 138                                "USB control request for firmware upload"
 139                                " failed. Error number %d\n", r);
 140                         goto error;
 141                 }
 142                 transfer_size = r & ~1;
 143
 144                 size -= transfer_size;
 145                 data += transfer_size;
 146                 code_offset += transfer_size/sizeof(u16);
 147         }
 148
 149         if (flags & REBOOT) {
 150                 u8 ret;
 151
 152                 r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
 153                         USB_REQ_FIRMWARE_CONFIRM,
 154                         USB_DIR_IN | USB_TYPE_VENDOR,
 155                         0, 0, &ret, sizeof(ret), 5000 /* ms */);
 156                 if (r != sizeof(ret)) {
 157                         dev_err(&udev->dev,
 158                                 "control request firmeware confirmation failed."
 159                                 " Return value %d\n", r);
 160                         if (r >= 0)
 161                                 r = -ENODEV;
 162                         goto error;
 163                 }
 164                 if (ret & 0x80) {
 165                         dev_err(&udev->dev,
 166                                 "Internal error while downloading."
 167                                 " Firmware confirm return value %#04x\n",
 168                                 (unsigned int)ret);
 169                         r = -ENODEV;
 170                         goto error;
 171                 }
 172                 dev_dbg_f(&udev->dev, "firmware confirm return value %#04x\n",
 173                         (unsigned int)ret);
 174         }
 175
 176         r = 0;
 177 error:
 178         kfree(p);
 179         return r;
 180 }
 181
 182 static u16 get_word(const void *data, u16 offset)
 183 {
 184         const __le16 *p = data;
 185         return le16_to_cpu(p[offset]);
 186 }
 187
 188 static char *get_fw_name(char *buffer, size_t size, u8 device_type,
 189                        const char* postfix)
 190 {
 191         scnprintf(buffer, size, "%s%s",
 192                 device_type == DEVICE_ZD1211B ?
 193                         FW_ZD1211B_PREFIX : FW_ZD1211_PREFIX,
 194                 postfix);
 195         return buffer;
 196 }
 197
 198 static int handle_version_mismatch(struct usb_device *udev, u8 device_type,
 199         const struct firmware *ub_fw)
 200 {
 201         const struct firmware *ur_fw = NULL;
 202         int offset;
 203         int r = 0;
 204         char fw_name[128];
 205
 206         r = request_fw_file(&ur_fw,
 207                 get_fw_name(fw_name, sizeof(fw_name), device_type, "ur"),
 208                 &udev->dev);
 209         if (r)
 210                 goto error;
 211
 212         r = upload_code(udev, ur_fw->data, ur_fw->size, FW_START, REBOOT);
 213         if (r)
 214                 goto error;
 215
 216         offset = (E2P_BOOT_CODE_OFFSET * sizeof(u16));
 217         r = upload_code(udev, ub_fw->data + offset, ub_fw->size - offset,
 218                 E2P_START + E2P_BOOT_CODE_OFFSET, REBOOT);
 219
 220         /* At this point, the vendor driver downloads the whole firmware
 221          * image, hacks around with version IDs, and uploads it again,
 222          * completely overwriting the boot code. We do not do this here as
 223          * it is not required on any tested devices, and it is suspected to
 224          * cause problems. */
 225 error:
 226         release_firmware(ur_fw);
 227         return r;
 228 }
 229
 230 static int upload_firmware(struct usb_device *udev, u8 device_type)
 231 {
 232         int r;
 233         u16 fw_bcdDevice;
 234         u16 bcdDevice;
 235         const struct firmware *ub_fw = NULL;
 236         const struct firmware *uph_fw = NULL;
 237         char fw_name[128];
 238
 239         bcdDevice = get_bcdDevice(udev);
 240
 241         r = request_fw_file(&ub_fw,
 242                 get_fw_name(fw_name, sizeof(fw_name), device_type,  "ub"),
 243                 &udev->dev);
 244         if (r)
 245                 goto error;
 246
 247         fw_bcdDevice = get_word(ub_fw->data, E2P_DATA_OFFSET);
 248
 249         if (fw_bcdDevice != bcdDevice) {
 250                 dev_info(&udev->dev,
 251                         "firmware version %#06x and device bootcode version "
 252                         "%#06x differ\n", fw_bcdDevice, bcdDevice);
 253                 if (bcdDevice <= 0x4313)
 254                         dev_warn(&udev->dev, "device has old bootcode, please "
 255                                 "report success or failure\n");
 256
 257                 r = handle_version_mismatch(udev, device_type, ub_fw);
 258                 if (r)
 259                         goto error;
 260         } else {
 261                 dev_dbg_f(&udev->dev,
 262                         "firmware device id %#06x is equal to the "
 263                         "actual device id\n", fw_bcdDevice);
 264         }
 265
 266
 267         r = request_fw_file(&uph_fw,
 268                 get_fw_name(fw_name, sizeof(fw_name), device_type, "uphr"),
 269                 &udev->dev);
 270         if (r)
 271                 goto error;
 272
 273         r = upload_code(udev, uph_fw->data, uph_fw->size, FW_START, REBOOT);
 274         if (r) {
 275                 dev_err(&udev->dev,
 276                         "Could not upload firmware code uph. Error number %d\n",
 277                         r);
 278         }
 279
 280         /* FALL-THROUGH */
 281 error:
 282         release_firmware(ub_fw);
 283         release_firmware(uph_fw);
 284         return r;
 285 }
 286
 287 #define urb_dev(urb) (&(urb)->dev->dev)
 288
 289 static inline void handle_regs_int(struct urb *urb)
 290 {
 291         struct zd_usb *usb = urb->context;
 292         struct zd_usb_interrupt *intr = &usb->intr;
 293         int len;
 294
 295         ZD_ASSERT(in_interrupt());
 296         spin_lock(&intr->lock);
 297
 298         if (intr->read_regs_enabled) {
 299                 intr->read_regs.length = len = urb->actual_length;
 300
 301                 if (len > sizeof(intr->read_regs.buffer))
 302                         len = sizeof(intr->read_regs.buffer);
 303                 memcpy(intr->read_regs.buffer, urb->transfer_buffer, len);
 304                 intr->read_regs_enabled = 0;
 305                 complete(&intr->read_regs.completion);
 306                 goto out;
 307         }
 308
 309         dev_dbg_f(urb_dev(urb), "regs interrupt ignored\n");
 310 out:
 311         spin_unlock(&intr->lock);
 312 }
 313
 314 static inline void handle_retry_failed_int(struct urb *urb)
 315 {
 316         struct zd_usb *usb = urb->context;
 317         struct zd_mac *mac = zd_usb_to_mac(usb);
 318         struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);
 319
 320         ieee->stats.tx_errors++;
 321         ieee->ieee_stats.tx_retry_limit_exceeded++;
 322         dev_dbg_f(urb_dev(urb), "retry failed interrupt\n");
 323 }
 324
 325
 326 static void int_urb_complete(struct urb *urb)
 327 {
 328         int r;
 329         struct usb_int_header *hdr;
 330
 331         switch (urb->status) {
 332         case 0:
 333                 break;
 334         case -ESHUTDOWN:
 335         case -EINVAL:
 336         case -ENODEV:
 337         case -ENOENT:
 338         case -ECONNRESET:
 339         case -EPIPE:
 340                 goto kfree;
 341         default:
 342                 goto resubmit;
 343         }
 344
 345         if (urb->actual_length < sizeof(hdr)) {
 346                 dev_dbg_f(urb_dev(urb), "error: urb %p to small\n", urb);
 347                 goto resubmit;
 348         }
 349
 350         hdr = urb->transfer_buffer;
 351         if (hdr->type != USB_INT_TYPE) {
 352                 dev_dbg_f(urb_dev(urb), "error: urb %p wrong type\n", urb);
 353                 goto resubmit;
 354         }
 355
 356         switch (hdr->id) {
 357         case USB_INT_ID_REGS:
 358                 handle_regs_int(urb);
 359                 break;
 360         case USB_INT_ID_RETRY_FAILED:
 361                 handle_retry_failed_int(urb);
 362                 break;
 363         default:
 364                 dev_dbg_f(urb_dev(urb), "error: urb %p unknown id %x\n", urb,
 365                         (unsigned int)hdr->id);
 366                 goto resubmit;
 367         }
 368
 369 resubmit:
 370         r = usb_submit_urb(urb, GFP_ATOMIC);
 371         if (r) {
 372                 dev_dbg_f(urb_dev(urb), "resubmit urb %p\n", urb);
 373                 goto kfree;
 374         }
 375         return;
 376 kfree:
 377         kfree(urb->transfer_buffer);
 378 }
 379
 380 static inline int int_urb_interval(struct usb_device *udev)
 381 {
 382         switch (udev->speed) {
 383         case USB_SPEED_HIGH:
 384                 return 4;
 385         case USB_SPEED_LOW:
 386                 return 10;
 387         case USB_SPEED_FULL:
 388         default:
 389                 return 1;
 390         }
 391 }
 392
 393 static inline int usb_int_enabled(struct zd_usb *usb)
 394 {
 395         unsigned long flags;
 396         struct zd_usb_interrupt *intr = &usb->intr;
 397         struct urb *urb;
 398
 399         spin_lock_irqsave(&intr->lock, flags);
 400         urb = intr->urb;
 401         spin_unlock_irqrestore(&intr->lock, flags);
 402         return urb != NULL;
 403 }
 404
 405 int zd_usb_enable_int(struct zd_usb *usb)
 406 {
 407         int r;
 408         struct usb_device *udev;
 409         struct zd_usb_interrupt *intr = &usb->intr;
 410         void *transfer_buffer = NULL;
 411         struct urb *urb;
 412
 413         dev_dbg_f(zd_usb_dev(usb), "\n");
 414
 415         urb = usb_alloc_urb(0, GFP_NOFS);
 416         if (!urb) {
 417                 r = -ENOMEM;
 418                 goto out;
 419         }
 420
 421         ZD_ASSERT(!irqs_disabled());
 422         spin_lock_irq(&intr->lock);
 423         if (intr->urb) {
 424                 spin_unlock_irq(&intr->lock);
 425                 r = 0;
 426                 goto error_free_urb;
 427         }
 428         intr->urb = urb;
 429         spin_unlock_irq(&intr->lock);
 430
 431         /* TODO: make it a DMA buffer */
 432         r = -ENOMEM;
 433         transfer_buffer = kmalloc(USB_MAX_EP_INT_BUFFER, GFP_NOFS);
 434         if (!transfer_buffer) {
 435                 dev_dbg_f(zd_usb_dev(usb),
 436                         "couldn't allocate transfer_buffer\n");
 437                 goto error_set_urb_null;
 438         }
 439
 440         udev = zd_usb_to_usbdev(usb);
 441         usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, EP_INT_IN),
 442                          transfer_buffer, USB_MAX_EP_INT_BUFFER,
 443                          int_urb_complete, usb,
 444                          intr->interval);
 445
 446         dev_dbg_f(zd_usb_dev(usb), "submit urb %p\n", intr->urb);
 447         r = usb_submit_urb(urb, GFP_NOFS);
 448         if (r) {
 449                 dev_dbg_f(zd_usb_dev(usb),
 450                          "Couldn't submit urb. Error number %d\n", r);
 451                 goto error;
 452         }
 453
 454         return 0;
 455 error:
 456         kfree(transfer_buffer);
 457 error_set_urb_null:
 458         spin_lock_irq(&intr->lock);
 459         intr->urb = NULL;
 460         spin_unlock_irq(&intr->lock);
 461 error_free_urb:
 462         usb_free_urb(urb);
 463 out:
 464         return r;
 465 }
 466
 467 void zd_usb_disable_int(struct zd_usb *usb)
 468 {
 469         unsigned long flags;
 470         struct zd_usb_interrupt *intr = &usb->intr;
 471         struct urb *urb;
 472
 473         spin_lock_irqsave(&intr->lock, flags);
 474         urb = intr->urb;
 475         if (!urb) {
 476                 spin_unlock_irqrestore(&intr->lock, flags);
 477                 return;
 478         }
 479         intr->urb = NULL;
 480         spin_unlock_irqrestore(&intr->lock, flags);
 481
 482         usb_kill_urb(urb);
 483         dev_dbg_f(zd_usb_dev(usb), "urb %p killed\n", urb);
 484         usb_free_urb(urb);
 485 }
 486
 487 static void handle_rx_packet(struct zd_usb *usb, const u8 *buffer,
 488                              unsigned int length)
 489 {
 490         int i;
 491         struct zd_mac *mac = zd_usb_to_mac(usb);
 492         const struct rx_length_info *length_info;
 493
 494         if (length < sizeof(struct rx_length_info)) {
 495                 /* It's not a complete packet anyhow. */
 496                 struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);
 497                 ieee->stats.rx_errors++;
 498                 ieee->stats.rx_length_errors++;
 499                 return;
 500         }
 501         length_info = (struct rx_length_info *)
 502                 (buffer + length - sizeof(struct rx_length_info));
 503
 504         /* It might be that three frames are merged into a single URB
 505          * transaction. We have to check for the length info tag.
 506          *
 507          * While testing we discovered that length_info might be unaligned,
 508          * because if USB transactions are merged, the last packet will not
 509          * be padded. Unaligned access might also happen if the length_info
 510          * structure is not present.
 511          */
 512         if (get_unaligned(&length_info->tag) == cpu_to_le16(RX_LENGTH_INFO_TAG))
 513         {
 514                 unsigned int l, k, n;
 515                 for (i = 0, l = 0;; i++) {
 516                         k = le16_to_cpu(get_unaligned(&length_info->length[i]));
 517                         if (k == 0)
 518                                 return;
 519                         n = l+k;
 520                         if (n > length)
 521                                 return;
 522                         zd_mac_rx_irq(mac, buffer+l, k);
 523                         if (i >= 2)
 524                                 return;
 525                         l = (n+3) & ~3;
 526                 }
 527         } else {
 528                 zd_mac_rx_irq(mac, buffer, length);
 529         }
 530 }
 531
 532 static void rx_urb_complete(struct urb *urb)
 533 {
 534         struct zd_usb *usb;
 535         struct zd_usb_rx *rx;
 536         const u8 *buffer;
 537         unsigned int length;
 538
 539         switch (urb->status) {
 540         case 0:
 541                 break;
 542         case -ESHUTDOWN:
 543         case -EINVAL:
 544         case -ENODEV:
 545         case -ENOENT:
 546         case -ECONNRESET:
 547         case -EPIPE:
 548                 return;
 549         default:
 550                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 551                 goto resubmit;
 552         }
 553
 554         buffer = urb->transfer_buffer;
 555         length = urb->actual_length;
 556         usb = urb->context;
 557         rx = &usb->rx;
 558
 559         if (length%rx->usb_packet_size > rx->usb_packet_size-4) {
 560                 /* If there is an old first fragment, we don't care. */
 561                 dev_dbg_f(urb_dev(urb), "*** first fragment ***\n");
 562                 ZD_ASSERT(length <= ARRAY_SIZE(rx->fragment));
 563                 spin_lock(&rx->lock);
 564                 memcpy(rx->fragment, buffer, length);
 565                 rx->fragment_length = length;
 566                 spin_unlock(&rx->lock);
 567                 goto resubmit;
 568         }
 569
 570         spin_lock(&rx->lock);
 571         if (rx->fragment_length > 0) {
 572                 /* We are on a second fragment, we believe */
 573                 ZD_ASSERT(length + rx->fragment_length <=
 574                           ARRAY_SIZE(rx->fragment));
 575                 dev_dbg_f(urb_dev(urb), "*** second fragment ***\n");
 576                 memcpy(rx->fragment+rx->fragment_length, buffer, length);
 577                 handle_rx_packet(usb, rx->fragment,
 578                                  rx->fragment_length + length);
 579                 rx->fragment_length = 0;
 580                 spin_unlock(&rx->lock);
 581         } else {
 582                 spin_unlock(&rx->lock);
 583                 handle_rx_packet(usb, buffer, length);
 584         }
 585
 586 resubmit:
 587         usb_submit_urb(urb, GFP_ATOMIC);
 588 }
 589
 590 static struct urb *alloc_urb(struct zd_usb *usb)
 591 {
 592         struct usb_device *udev = zd_usb_to_usbdev(usb);
 593         struct urb *urb;
 594         void *buffer;
 595
 596         urb = usb_alloc_urb(0, GFP_NOFS);
 597         if (!urb)
 598                 return NULL;
 599         buffer = usb_buffer_alloc(udev, USB_MAX_RX_SIZE, GFP_NOFS,
 600                                   &urb->transfer_dma);
 601         if (!buffer) {
 602                 usb_free_urb(urb);
 603                 return NULL;
 604         }
 605
 606         usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_DATA_IN),
 607                           buffer, USB_MAX_RX_SIZE,
 608                           rx_urb_complete, usb);
 609         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 610
 611         return urb;
 612 }
 613
 614 static void free_urb(struct urb *urb)
 615 {
 616         if (!urb)
 617                 return;
 618         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 619                         urb->transfer_buffer, urb->transfer_dma);
 620         usb_free_urb(urb);
 621 }
 622
 623 int zd_usb_enable_rx(struct zd_usb *usb)
 624 {
 625         int i, r;
 626         struct zd_usb_rx *rx = &usb->rx;
 627         struct urb **urbs;
 628
 629         dev_dbg_f(zd_usb_dev(usb), "\n");
 630
 631         r = -ENOMEM;
 632         urbs = kcalloc(URBS_COUNT, sizeof(struct urb *), GFP_NOFS);
 633         if (!urbs)
 634                 goto error;
 635         for (i = 0; i < URBS_COUNT; i++) {
 636                 urbs[i] = alloc_urb(usb);
 637                 if (!urbs[i])
 638                         goto error;
 639         }
 640
 641         ZD_ASSERT(!irqs_disabled());
 642         spin_lock_irq(&rx->lock);
 643         if (rx->urbs) {
 644                 spin_unlock_irq(&rx->lock);
 645                 r = 0;
 646                 goto error;
 647         }
 648         rx->urbs = urbs;
 649         rx->urbs_count = URBS_COUNT;
 650         spin_unlock_irq(&rx->lock);
 651
 652         for (i = 0; i < URBS_COUNT; i++) {
 653                 r = usb_submit_urb(urbs[i], GFP_NOFS);
 654                 if (r)
 655                         goto error_submit;
 656         }
 657
 658         return 0;
 659 error_submit:
 660         for (i = 0; i < URBS_COUNT; i++) {
 661                 usb_kill_urb(urbs[i]);
 662         }
 663         spin_lock_irq(&rx->lock);
 664         rx->urbs = NULL;
 665         rx->urbs_count = 0;
 666         spin_unlock_irq(&rx->lock);
 667 error:
 668         if (urbs) {
 669                 for (i = 0; i < URBS_COUNT; i++)
 670                         free_urb(urbs[i]);
 671         }
 672         return r;
 673 }
 674
 675 void zd_usb_disable_rx(struct zd_usb *usb)
 676 {
 677         int i;
 678         unsigned long flags;
 679         struct urb **urbs;
 680         unsigned int count;
 681         struct zd_usb_rx *rx = &usb->rx;
 682
 683         spin_lock_irqsave(&rx->lock, flags);
 684         urbs = rx->urbs;
 685         count = rx->urbs_count;
 686         spin_unlock_irqrestore(&rx->lock, flags);
 687         if (!urbs)
 688                 return;
 689
 690         for (i = 0; i < count; i++) {
 691                 usb_kill_urb(urbs[i]);
 692                 free_urb(urbs[i]);
 693         }
 694         kfree(urbs);
 695
 696         spin_lock_irqsave(&rx->lock, flags);
 697         rx->urbs = NULL;
 698         rx->urbs_count = 0;
 699         spin_unlock_irqrestore(&rx->lock, flags);
 700 }
 701
 702 static void tx_urb_complete(struct urb *urb)
 703 {
 704         int r;
 705
 706         switch (urb->status) {
 707         case 0:
 708                 break;
 709         case -ESHUTDOWN:
 710         case -EINVAL:
 711         case -ENODEV:
 712         case -ENOENT:
 713         case -ECONNRESET:
 714         case -EPIPE:
 715                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 716                 break;
 717         default:
 718                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 719                 goto resubmit;
 720         }
 721 free_urb:
 722         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 723                         urb->transfer_buffer, urb->transfer_dma);
 724         usb_free_urb(urb);
 725         return;
 726 resubmit:
 727         r = usb_submit_urb(urb, GFP_ATOMIC);
 728         if (r) {
 729                 dev_dbg_f(urb_dev(urb), "error resubmit urb %p %d\n", urb, r);
 730                 goto free_urb;
 731         }
 732 }
 733
 734 /* Puts the frame on the USB endpoint. It doesn't wait for
 735  * completion. The frame must contain the control set.
 736  */
 737 int zd_usb_tx(struct zd_usb *usb, const u8 *frame, unsigned int length)
 738 {
 739         int r;
 740         struct usb_device *udev = zd_usb_to_usbdev(usb);
 741         struct urb *urb;
 742         void *buffer;
 743
 744         urb = usb_alloc_urb(0, GFP_ATOMIC);
 745         if (!urb) {
 746                 r = -ENOMEM;
 747                 goto out;
 748         }
 749
 750         buffer = usb_buffer_alloc(zd_usb_to_usbdev(usb), length, GFP_ATOMIC,
 751                                   &urb->transfer_dma);
 752         if (!buffer) {
 753                 r = -ENOMEM;
 754                 goto error_free_urb;
 755         }
 756         memcpy(buffer, frame, length);
 757
 758         usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, EP_DATA_OUT),
 759                           buffer, length, tx_urb_complete, NULL);
 760         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 761
 762         r = usb_submit_urb(urb, GFP_ATOMIC);
 763         if (r)
 764                 goto error;
 765         return 0;
 766 error:
 767         usb_buffer_free(zd_usb_to_usbdev(usb), length, buffer,
 768                         urb->transfer_dma);
 769 error_free_urb:
 770         usb_free_urb(urb);
 771 out:
 772         return r;
 773 }
 774
 775 static inline void init_usb_interrupt(struct zd_usb *usb)
 776 {
 777         struct zd_usb_interrupt *intr = &usb->intr;
 778
 779         spin_lock_init(&intr->lock);
 780         intr->interval = int_urb_interval(zd_usb_to_usbdev(usb));
 781         init_completion(&intr->read_regs.completion);
 782         intr->read_regs.cr_int_addr = cpu_to_le16((u16)CR_INTERRUPT);
 783 }
 784
 785 static inline void init_usb_rx(struct zd_usb *usb)
 786 {
 787         struct zd_usb_rx *rx = &usb->rx;
 788         spin_lock_init(&rx->lock);
 789         if (interface_to_usbdev(usb->intf)->speed == USB_SPEED_HIGH) {
 790                 rx->usb_packet_size = 512;
 791         } else {
 792                 rx->usb_packet_size = 64;
 793         }
 794         ZD_ASSERT(rx->fragment_length == 0);
 795 }
 796
 797 static inline void init_usb_tx(struct zd_usb *usb)
 798 {
 799         /* FIXME: at this point we will allocate a fixed number of urb's for
 800          * use in a cyclic scheme */
 801 }
 802
 803 void zd_usb_init(struct zd_usb *usb, struct net_device *netdev,
 804                  struct usb_interface *intf)
 805 {
 806         memset(usb, 0, sizeof(*usb));
 807         usb->intf = usb_get_intf(intf);
 808         usb_set_intfdata(usb->intf, netdev);
 809         init_usb_interrupt(usb);
 810         init_usb_tx(usb);
 811         init_usb_rx(usb);
 812 }
 813
 814 void zd_usb_clear(struct zd_usb *usb)
 815 {
 816         usb_set_intfdata(usb->intf, NULL);
 817         usb_put_intf(usb->intf);
 818         ZD_MEMCLEAR(usb, sizeof(*usb));
 819         /* FIXME: usb_interrupt, usb_tx, usb_rx? */
 820 }
 821
 822 static const char *speed(enum usb_device_speed speed)
 823 {
 824         switch (speed) {
 825         case USB_SPEED_LOW:
 826                 return "low";
 827         case USB_SPEED_FULL:
 828                 return "full";
 829         case USB_SPEED_HIGH:
 830                 return "high";
 831         default:
 832                 return "unknown speed";
 833         }
 834 }
 835
 836 static int scnprint_id(struct usb_device *udev, char *buffer, size_t size)
 837 {
 838         return scnprintf(buffer, size, "%04hx:%04hx v%04hx %s",
 839                 le16_to_cpu(udev->descriptor.idVendor),
 840                 le16_to_cpu(udev->descriptor.idProduct),
 841                 get_bcdDevice(udev),
 842                 speed(udev->speed));
 843 }
 844
 845 int zd_usb_scnprint_id(struct zd_usb *usb, char *buffer, size_t size)
 846 {
 847         struct usb_device *udev = interface_to_usbdev(usb->intf);
 848         return scnprint_id(udev, buffer, size);
 849 }
 850
 851 #ifdef DEBUG
 852 static void print_id(struct usb_device *udev)
 853 {
 854         char buffer[40];
 855
 856         scnprint_id(udev, buffer, sizeof(buffer));
 857         buffer[sizeof(buffer)-1] = 0;
 858         dev_dbg_f(&udev->dev, "%s\n", buffer);
 859 }
 860 #else
 861 #define print_id(udev) do { } while (0)
 862 #endif
 863
 864 static int eject_installer(struct usb_interface *intf)
 865 {
 866         struct usb_device *udev = interface_to_usbdev(intf);
 867         struct usb_host_interface *iface_desc = &intf->altsetting[0];
 868         struct usb_endpoint_descriptor *endpoint;
 869         unsigned char *cmd;
 870         u8 bulk_out_ep;
 871         int r;
 872
 873         /* Find bulk out endpoint */
 874         endpoint = &iface_desc->endpoint[1].desc;
 875         if ((endpoint->bEndpointAddress & USB_TYPE_MASK) == USB_DIR_OUT &&
 876             (endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
 877             USB_ENDPOINT_XFER_BULK) {
 878                 bulk_out_ep = endpoint->bEndpointAddress;
 879         } else {
 880                 dev_err(&udev->dev,
 881                         "zd1211rw: Could not find bulk out endpoint\n");
 882                 return -ENODEV;
 883         }
 884
 885         cmd = kzalloc(31, GFP_KERNEL);
 886         if (cmd == NULL)
 887                 return -ENODEV;
 888
 889         /* USB bulk command block */
 890         cmd[0] = 0x55;  /* bulk command signature */
 891         cmd[1] = 0x53;  /* bulk command signature */
 892         cmd[2] = 0x42;  /* bulk command signature */
 893         cmd[3] = 0x43;  /* bulk command signature */
 894         cmd[14] = 6;    /* command length */
 895
 896         cmd[15] = 0x1b; /* SCSI command: START STOP UNIT */
 897         cmd[19] = 0x2;  /* eject disc */
 898
 899         dev_info(&udev->dev, "Ejecting virtual installer media...\n");
 900         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, bulk_out_ep),
 901                 cmd, 31, NULL, 2000);
 902         kfree(cmd);
 903         if (r)
 904                 return r;
 905
 906         /* At this point, the device disconnects and reconnects with the real
 907          * ID numbers. */
 908
 909         usb_set_intfdata(intf, NULL);
 910         return 0;
 911 }
 912
 913 static int probe(struct usb_interface *intf, const struct usb_device_id *id)
 914 {
 915         int r;
 916         struct usb_device *udev = interface_to_usbdev(intf);
 917         struct net_device *netdev = NULL;
 918
 919         print_id(udev);
 920
 921         if (id->driver_info & DEVICE_INSTALLER)
 922                 return eject_installer(intf);
 923
 924         switch (udev->speed) {
 925         case USB_SPEED_LOW:
 926         case USB_SPEED_FULL:
 927         case USB_SPEED_HIGH:
 928                 break;
 929         default:
 930                 dev_dbg_f(&intf->dev, "Unknown USB speed\n");
 931                 r = -ENODEV;
 932                 goto error;
 933         }
 934
 935         usb_reset_device(interface_to_usbdev(intf));
 936
 937         netdev = zd_netdev_alloc(intf);
 938         if (netdev == NULL) {
 939                 r = -ENOMEM;
 940                 goto error;
 941         }
 942
 943         r = upload_firmware(udev, id->driver_info);
 944         if (r) {
 945                 dev_err(&intf->dev,
 946                        "couldn't load firmware. Error number %d\n", r);
 947                 goto error;
 948         }
 949
 950         r = usb_reset_configuration(udev);
 951         if (r) {
 952                 dev_dbg_f(&intf->dev,
 953                         "couldn't reset configuration. Error number %d\n", r);
 954                 goto error;
 955         }
 956
 957         /* At this point the interrupt endpoint is not generally enabled. We
 958          * save the USB bandwidth until the network device is opened. But
 959          * notify that the initialization of the MAC will require the
 960          * interrupts to be temporary enabled.
 961          */
 962         r = zd_mac_init_hw(zd_netdev_mac(netdev), id->driver_info);
 963         if (r) {
 964                 dev_dbg_f(&intf->dev,
 965                          "couldn't initialize mac. Error number %d\n", r);
 966                 goto error;
 967         }
 968
 969         r = register_netdev(netdev);
 970         if (r) {
 971                 dev_dbg_f(&intf->dev,
 972                          "couldn't register netdev. Error number %d\n", r);
 973                 goto error;
 974         }
 975
 976         dev_dbg_f(&intf->dev, "successful\n");
 977         dev_info(&intf->dev,"%s\n", netdev->name);
 978         return 0;
 979 error:
 980         usb_reset_device(interface_to_usbdev(intf));
 981         zd_netdev_free(netdev);
 982         return r;
 983 }
 984
 985 static void disconnect(struct usb_interface *intf)
 986 {
 987         struct net_device *netdev = zd_intf_to_netdev(intf);
 988         struct zd_mac *mac = zd_netdev_mac(netdev);
 989         struct zd_usb *usb = &mac->chip.usb;
 990
 991         /* Either something really bad happened, or we're just dealing with
 992          * a DEVICE_INSTALLER. */
 993         if (netdev == NULL)
 994                 return;
 995
 996         dev_dbg_f(zd_usb_dev(usb), "\n");
 997
 998         zd_netdev_disconnect(netdev);
 999
1000         /* Just in case something has gone wrong! */
1001         zd_usb_disable_rx(usb);
1002         zd_usb_disable_int(usb);
1003
1004         /* If the disconnect has been caused by a removal of the
1005          * driver module, the reset allows reloading of the driver. If the
1006          * reset will not be executed here, the upload of the firmware in the
1007          * probe function caused by the reloading of the driver will fail.
1008          */
1009         usb_reset_device(interface_to_usbdev(intf));
1010
1011         zd_netdev_free(netdev);
1012         dev_dbg(&intf->dev, "disconnected\n");
1013 }
1014
1015 static struct usb_driver driver = {
1016         .name           = "zd1211rw",
1017         .id_table       = usb_ids,
1018         .probe          = probe,
1019         .disconnect     = disconnect,
1020 };
1021
1022 struct workqueue_struct *zd_workqueue;
1023
1024 static int __init usb_init(void)
1025 {
1026         int r;
1027
1028         pr_debug("%s usb_init()\n", driver.name);
1029
1030         zd_workqueue = create_singlethread_workqueue(driver.name);
1031         if (zd_workqueue == NULL) {
1032                 printk(KERN_ERR "%s couldn't create workqueue\n", driver.name);
1033                 return -ENOMEM;
1034         }
1035
1036         r = usb_register(&driver);
1037         if (r) {
1038                 destroy_workqueue(zd_workqueue);
1039                 printk(KERN_ERR "%s usb_register() failed. Error number %d\n",
1040                        driver.name, r);
1041                 return r;
1042         }
1043
1044         pr_debug("%s initialized\n", driver.name);
1045         return 0;
1046 }
1047
1048 static void __exit usb_exit(void)
1049 {
1050         pr_debug("%s usb_exit()\n", driver.name);
1051         usb_deregister(&driver);
1052         destroy_workqueue(zd_workqueue);
1053 }
1054
1055 module_init(usb_init);
1056 module_exit(usb_exit);
1057
1058 static int usb_int_regs_length(unsigned int count)
1059 {
1060         return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data);
1061 }
1062
1063 static void prepare_read_regs_int(struct zd_usb *usb)
1064 {
1065         struct zd_usb_interrupt *intr = &usb->intr;
1066
1067         spin_lock_irq(&intr->lock);
1068         intr->read_regs_enabled = 1;
1069         INIT_COMPLETION(intr->read_regs.completion);
1070         spin_unlock_irq(&intr->lock);
1071 }
1072
1073 static void disable_read_regs_int(struct zd_usb *usb)
1074 {
1075         struct zd_usb_interrupt *intr = &usb->intr;
1076
1077         spin_lock_irq(&intr->lock);
1078         intr->read_regs_enabled = 0;
1079         spin_unlock_irq(&intr->lock);
1080 }
1081
1082 static int get_results(struct zd_usb *usb, u16 *values,
1083                        struct usb_req_read_regs *req, unsigned int count)
1084 {
1085         int r;
1086         int i;
1087         struct zd_usb_interrupt *intr = &usb->intr;
1088         struct read_regs_int *rr = &intr->read_regs;
1089         struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
1090
1091         spin_lock_irq(&intr->lock);
1092
1093         r = -EIO;
1094         /* The created block size seems to be larger than expected.
1095          * However results appear to be correct.
1096          */
1097         if (rr->length < usb_int_regs_length(count)) {
1098                 dev_dbg_f(zd_usb_dev(usb),
1099                          "error: actual length %d less than expected %d\n",
1100                          rr->length, usb_int_regs_length(count));
1101                 goto error_unlock;
1102         }
1103         if (rr->length > sizeof(rr->buffer)) {
1104                 dev_dbg_f(zd_usb_dev(usb),
1105                          "error: actual length %d exceeds buffer size %zu\n",
1106                          rr->length, sizeof(rr->buffer));
1107                 goto error_unlock;
1108         }
1109
1110         for (i = 0; i < count; i++) {
1111                 struct reg_data *rd = &regs->regs[i];
1112                 if (rd->addr != req->addr[i]) {
1113                         dev_dbg_f(zd_usb_dev(usb),
1114                                  "rd[%d] addr %#06hx expected %#06hx\n", i,
1115                                  le16_to_cpu(rd->addr),
1116                                  le16_to_cpu(req->addr[i]));
1117                         goto error_unlock;
1118                 }
1119                 values[i] = le16_to_cpu(rd->value);
1120         }
1121
1122         r = 0;
1123 error_unlock:
1124         spin_unlock_irq(&intr->lock);
1125         return r;
1126 }
1127
1128 int zd_usb_ioread16v(struct zd_usb *usb, u16 *values,
1129                      const zd_addr_t *addresses, unsigned int count)
1130 {
1131         int r;
1132         int i, req_len, actual_req_len;
1133         struct usb_device *udev;
1134         struct usb_req_read_regs *req = NULL;
1135         unsigned long timeout;
1136
1137         if (count < 1) {
1138                 dev_dbg_f(zd_usb_dev(usb), "error: count is zero\n");
1139                 return -EINVAL;
1140         }
1141         if (count > USB_MAX_IOREAD16_COUNT) {
1142                 dev_dbg_f(zd_usb_dev(usb),
1143                          "error: count %u exceeds possible max %u\n",
1144                          count, USB_MAX_IOREAD16_COUNT);
1145                 return -EINVAL;
1146         }
1147         if (in_atomic()) {
1148                 dev_dbg_f(zd_usb_dev(usb),
1149                          "error: io in atomic context not supported\n");
1150                 return -EWOULDBLOCK;
1151         }
1152         if (!usb_int_enabled(usb)) {
1153                  dev_dbg_f(zd_usb_dev(usb),
1154                           "error: usb interrupt not enabled\n");
1155                 return -EWOULDBLOCK;
1156         }
1157
1158         req_len = sizeof(struct usb_req_read_regs) + count * sizeof(__le16);
1159         req = kmalloc(req_len, GFP_NOFS);
1160         if (!req)
1161                 return -ENOMEM;
1162         req->id = cpu_to_le16(USB_REQ_READ_REGS);
1163         for (i = 0; i < count; i++)
1164                 req->addr[i] = cpu_to_le16((u16)addresses[i]);
1165
1166         udev = zd_usb_to_usbdev(usb);
1167         prepare_read_regs_int(usb);
1168         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1169                          req, req_len, &actual_req_len, 1000 /* ms */);
1170         if (r) {
1171                 dev_dbg_f(zd_usb_dev(usb),
1172                         "error in usb_bulk_msg(). Error number %d\n", r);
1173                 goto error;
1174         }
1175         if (req_len != actual_req_len) {
1176                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()\n"
1177                         " req_len %d != actual_req_len %d\n",
1178                         req_len, actual_req_len);
1179                 r = -EIO;
1180                 goto error;
1181         }
1182
1183         timeout = wait_for_completion_timeout(&usb->intr.read_regs.completion,
1184                                               msecs_to_jiffies(1000));
1185         if (!timeout) {
1186                 disable_read_regs_int(usb);
1187                 dev_dbg_f(zd_usb_dev(usb), "read timed out\n");
1188                 r = -ETIMEDOUT;
1189                 goto error;
1190         }
1191
1192         r = get_results(usb, values, req, count);
1193 error:
1194         kfree(req);
1195         return r;
1196 }
1197
1198 int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
1199                       unsigned int count)
1200 {
1201         int r;
1202         struct usb_device *udev;
1203         struct usb_req_write_regs *req = NULL;
1204         int i, req_len, actual_req_len;
1205
1206         if (count == 0)
1207                 return 0;
1208         if (count > USB_MAX_IOWRITE16_COUNT) {
1209                 dev_dbg_f(zd_usb_dev(usb),
1210                         "error: count %u exceeds possible max %u\n",
1211                         count, USB_MAX_IOWRITE16_COUNT);
1212                 return -EINVAL;
1213         }
1214         if (in_atomic()) {
1215                 dev_dbg_f(zd_usb_dev(usb),
1216                         "error: io in atomic context not supported\n");
1217                 return -EWOULDBLOCK;
1218         }
1219
1220         req_len = sizeof(struct usb_req_write_regs) +
1221                   count * sizeof(struct reg_data);
1222         req = kmalloc(req_len, GFP_NOFS);
1223         if (!req)
1224                 return -ENOMEM;
1225
1226         req->id = cpu_to_le16(USB_REQ_WRITE_REGS);
1227         for (i = 0; i < count; i++) {
1228                 struct reg_data *rw  = &req->reg_writes[i];
1229                 rw->addr = cpu_to_le16((u16)ioreqs[i].addr);
1230                 rw->value = cpu_to_le16(ioreqs[i].value);
1231         }
1232
1233         udev = zd_usb_to_usbdev(usb);
1234         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1235                          req, req_len, &actual_req_len, 1000 /* ms */);
1236         if (r) {
1237                 dev_dbg_f(zd_usb_dev(usb),
1238                         "error in usb_bulk_msg(). Error number %d\n", r);
1239                 goto error;
1240         }
1241         if (req_len != actual_req_len) {
1242                 dev_dbg_f(zd_usb_dev(usb),
1243                         "error in usb_bulk_msg()"
1244                         " req_len %d != actual_req_len %d\n",
1245                         req_len, actual_req_len);
1246                 r = -EIO;
1247                 goto error;
1248         }
1249
1250         /* FALL-THROUGH with r == 0 */
1251 error:
1252         kfree(req);
1253         return r;
1254 }
1255
1256 int zd_usb_rfwrite(struct zd_usb *usb, u32 value, u8 bits)
1257 {
1258         int r;
1259         struct usb_device *udev;
1260         struct usb_req_rfwrite *req = NULL;
1261         int i, req_len, actual_req_len;
1262         u16 bit_value_template;
1263
1264         if (in_atomic()) {
1265                 dev_dbg_f(zd_usb_dev(usb),
1266                         "error: io in atomic context not supported\n");
1267                 return -EWOULDBLOCK;
1268         }
1269         if (bits < USB_MIN_RFWRITE_BIT_COUNT) {
1270                 dev_dbg_f(zd_usb_dev(usb),
1271                         "error: bits %d are smaller than"
1272                         " USB_MIN_RFWRITE_BIT_COUNT %d\n",
1273                         bits, USB_MIN_RFWRITE_BIT_COUNT);
1274                 return -EINVAL;
1275         }
1276         if (bits > USB_MAX_RFWRITE_BIT_COUNT) {
1277                 dev_dbg_f(zd_usb_dev(usb),
1278                         "error: bits %d exceed USB_MAX_RFWRITE_BIT_COUNT %d\n",
1279                         bits, USB_MAX_RFWRITE_BIT_COUNT);
1280                 return -EINVAL;
1281         }
1282 #ifdef DEBUG
1283         if (value & (~0UL << bits)) {
1284                 dev_dbg_f(zd_usb_dev(usb),
1285                         "error: value %#09x has bits >= %d set\n",
1286                         value, bits);
1287                 return -EINVAL;
1288         }
1289 #endif /* DEBUG */
1290
1291         dev_dbg_f(zd_usb_dev(usb), "value %#09x bits %d\n", value, bits);
1292
1293         r = zd_usb_ioread16(usb, &bit_value_template, CR203);
1294         if (r) {
1295                 dev_dbg_f(zd_usb_dev(usb),
1296                         "error %d: Couldn't read CR203\n", r);
1297                 goto out;
1298         }
1299         bit_value_template &= ~(RF_IF_LE|RF_CLK|RF_DATA);
1300
1301         req_len = sizeof(struct usb_req_rfwrite) + bits * sizeof(__le16);
1302         req = kmalloc(req_len, GFP_NOFS);
1303         if (!req)
1304                 return -ENOMEM;
1305
1306         req->id = cpu_to_le16(USB_REQ_WRITE_RF);
1307         /* 1: 3683a, but not used in ZYDAS driver */
1308         req->value = cpu_to_le16(2);
1309         req->bits = cpu_to_le16(bits);
1310
1311         for (i = 0; i < bits; i++) {
1312                 u16 bv = bit_value_template;
1313                 if (value & (1 << (bits-1-i)))
1314                         bv |= RF_DATA;
1315                 req->bit_values[i] = cpu_to_le16(bv);
1316         }
1317
1318         udev = zd_usb_to_usbdev(usb);
1319         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1320                          req, req_len, &actual_req_len, 1000 /* ms */);
1321         if (r) {
1322                 dev_dbg_f(zd_usb_dev(usb),
1323                         "error in usb_bulk_msg(). Error number %d\n", r);
1324                 goto out;
1325         }
1326         if (req_len != actual_req_len) {
1327                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()"
1328                         " req_len %d != actual_req_len %d\n",
1329                         req_len, actual_req_len);
1330                 r = -EIO;
1331                 goto out;
1332         }
1333
1334         /* FALL-THROUGH with r == 0 */
1335 out:
1336         kfree(req);
1337         return r;
1338 }