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         { USB_DEVICE(0x0b05, 0x171b), .driver_info = DEVICE_ZD1211B },
  66         { USB_DEVICE(0x0586, 0x3410), .driver_info = DEVICE_ZD1211B },
  67         { USB_DEVICE(0x0baf, 0x0121), .driver_info = DEVICE_ZD1211B },
  68         /* "Driverless" devices that need ejecting */
  69         { USB_DEVICE(0x0ace, 0x2011), .driver_info = DEVICE_INSTALLER },
  70         {}
  71 };
  72
  73 MODULE_LICENSE("GPL");
  74 MODULE_DESCRIPTION("USB driver for devices with the ZD1211 chip.");
  75 MODULE_AUTHOR("Ulrich Kunitz");
  76 MODULE_AUTHOR("Daniel Drake");
  77 MODULE_VERSION("1.0");
  78 MODULE_DEVICE_TABLE(usb, usb_ids);
  79
  80 #define FW_ZD1211_PREFIX        "zd1211/zd1211_"
  81 #define FW_ZD1211B_PREFIX       "zd1211/zd1211b_"
  82
  83 /* USB device initialization */
  84
  85 static int request_fw_file(
  86         const struct firmware **fw, const char *name, struct device *device)
  87 {
  88         int r;
  89
  90         dev_dbg_f(device, "fw name %s\n", name);
  91
  92         r = request_firmware(fw, name, device);
  93         if (r)
  94                 dev_err(device,
  95                        "Could not load firmware file %s. Error number %d\n",
  96                        name, r);
  97         return r;
  98 }
  99
 100 static inline u16 get_bcdDevice(const struct usb_device *udev)
 101 {
 102         return le16_to_cpu(udev->descriptor.bcdDevice);
 103 }
 104
 105 enum upload_code_flags {
 106         REBOOT = 1,
 107 };
 108
 109 /* Ensures that MAX_TRANSFER_SIZE is even. */
 110 #define MAX_TRANSFER_SIZE (USB_MAX_TRANSFER_SIZE & ~1)
 111
 112 static int upload_code(struct usb_device *udev,
 113         const u8 *data, size_t size, u16 code_offset, int flags)
 114 {
 115         u8 *p;
 116         int r;
 117
 118         /* USB request blocks need "kmalloced" buffers.
 119          */
 120         p = kmalloc(MAX_TRANSFER_SIZE, GFP_KERNEL);
 121         if (!p) {
 122                 dev_err(&udev->dev, "out of memory\n");
 123                 r = -ENOMEM;
 124                 goto error;
 125         }
 126
 127         size &= ~1;
 128         while (size > 0) {
 129                 size_t transfer_size = size <= MAX_TRANSFER_SIZE ?
 130                         size : MAX_TRANSFER_SIZE;
 131
 132                 dev_dbg_f(&udev->dev, "transfer size %zu\n", transfer_size);
 133
 134                 memcpy(p, data, transfer_size);
 135                 r = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 136                         USB_REQ_FIRMWARE_DOWNLOAD,
 137                         USB_DIR_OUT | USB_TYPE_VENDOR,
 138                         code_offset, 0, p, transfer_size, 1000 /* ms */);
 139                 if (r < 0) {
 140                         dev_err(&udev->dev,
 141                                "USB control request for firmware upload"
 142                                " failed. Error number %d\n", r);
 143                         goto error;
 144                 }
 145                 transfer_size = r & ~1;
 146
 147                 size -= transfer_size;
 148                 data += transfer_size;
 149                 code_offset += transfer_size/sizeof(u16);
 150         }
 151
 152         if (flags & REBOOT) {
 153                 u8 ret;
 154
 155                 r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
 156                         USB_REQ_FIRMWARE_CONFIRM,
 157                         USB_DIR_IN | USB_TYPE_VENDOR,
 158                         0, 0, &ret, sizeof(ret), 5000 /* ms */);
 159                 if (r != sizeof(ret)) {
 160                         dev_err(&udev->dev,
 161                                 "control request firmeware confirmation failed."
 162                                 " Return value %d\n", r);
 163                         if (r >= 0)
 164                                 r = -ENODEV;
 165                         goto error;
 166                 }
 167                 if (ret & 0x80) {
 168                         dev_err(&udev->dev,
 169                                 "Internal error while downloading."
 170                                 " Firmware confirm return value %#04x\n",
 171                                 (unsigned int)ret);
 172                         r = -ENODEV;
 173                         goto error;
 174                 }
 175                 dev_dbg_f(&udev->dev, "firmware confirm return value %#04x\n",
 176                         (unsigned int)ret);
 177         }
 178
 179         r = 0;
 180 error:
 181         kfree(p);
 182         return r;
 183 }
 184
 185 static u16 get_word(const void *data, u16 offset)
 186 {
 187         const __le16 *p = data;
 188         return le16_to_cpu(p[offset]);
 189 }
 190
 191 static char *get_fw_name(char *buffer, size_t size, u8 device_type,
 192                        const char* postfix)
 193 {
 194         scnprintf(buffer, size, "%s%s",
 195                 device_type == DEVICE_ZD1211B ?
 196                         FW_ZD1211B_PREFIX : FW_ZD1211_PREFIX,
 197                 postfix);
 198         return buffer;
 199 }
 200
 201 static int handle_version_mismatch(struct usb_device *udev, u8 device_type,
 202         const struct firmware *ub_fw)
 203 {
 204         const struct firmware *ur_fw = NULL;
 205         int offset;
 206         int r = 0;
 207         char fw_name[128];
 208
 209         r = request_fw_file(&ur_fw,
 210                 get_fw_name(fw_name, sizeof(fw_name), device_type, "ur"),
 211                 &udev->dev);
 212         if (r)
 213                 goto error;
 214
 215         r = upload_code(udev, ur_fw->data, ur_fw->size, FW_START, REBOOT);
 216         if (r)
 217                 goto error;
 218
 219         offset = (E2P_BOOT_CODE_OFFSET * sizeof(u16));
 220         r = upload_code(udev, ub_fw->data + offset, ub_fw->size - offset,
 221                 E2P_START + E2P_BOOT_CODE_OFFSET, REBOOT);
 222
 223         /* At this point, the vendor driver downloads the whole firmware
 224          * image, hacks around with version IDs, and uploads it again,
 225          * completely overwriting the boot code. We do not do this here as
 226          * it is not required on any tested devices, and it is suspected to
 227          * cause problems. */
 228 error:
 229         release_firmware(ur_fw);
 230         return r;
 231 }
 232
 233 static int upload_firmware(struct usb_device *udev, u8 device_type)
 234 {
 235         int r;
 236         u16 fw_bcdDevice;
 237         u16 bcdDevice;
 238         const struct firmware *ub_fw = NULL;
 239         const struct firmware *uph_fw = NULL;
 240         char fw_name[128];
 241
 242         bcdDevice = get_bcdDevice(udev);
 243
 244         r = request_fw_file(&ub_fw,
 245                 get_fw_name(fw_name, sizeof(fw_name), device_type,  "ub"),
 246                 &udev->dev);
 247         if (r)
 248                 goto error;
 249
 250         fw_bcdDevice = get_word(ub_fw->data, E2P_DATA_OFFSET);
 251
 252         if (fw_bcdDevice != bcdDevice) {
 253                 dev_info(&udev->dev,
 254                         "firmware version %#06x and device bootcode version "
 255                         "%#06x differ\n", fw_bcdDevice, bcdDevice);
 256                 if (bcdDevice <= 0x4313)
 257                         dev_warn(&udev->dev, "device has old bootcode, please "
 258                                 "report success or failure\n");
 259
 260                 r = handle_version_mismatch(udev, device_type, ub_fw);
 261                 if (r)
 262                         goto error;
 263         } else {
 264                 dev_dbg_f(&udev->dev,
 265                         "firmware device id %#06x is equal to the "
 266                         "actual device id\n", fw_bcdDevice);
 267         }
 268
 269
 270         r = request_fw_file(&uph_fw,
 271                 get_fw_name(fw_name, sizeof(fw_name), device_type, "uphr"),
 272                 &udev->dev);
 273         if (r)
 274                 goto error;
 275
 276         r = upload_code(udev, uph_fw->data, uph_fw->size, FW_START, REBOOT);
 277         if (r) {
 278                 dev_err(&udev->dev,
 279                         "Could not upload firmware code uph. Error number %d\n",
 280                         r);
 281         }
 282
 283         /* FALL-THROUGH */
 284 error:
 285         release_firmware(ub_fw);
 286         release_firmware(uph_fw);
 287         return r;
 288 }
 289
 290 #define urb_dev(urb) (&(urb)->dev->dev)
 291
 292 static inline void handle_regs_int(struct urb *urb)
 293 {
 294         struct zd_usb *usb = urb->context;
 295         struct zd_usb_interrupt *intr = &usb->intr;
 296         int len;
 297
 298         ZD_ASSERT(in_interrupt());
 299         spin_lock(&intr->lock);
 300
 301         if (intr->read_regs_enabled) {
 302                 intr->read_regs.length = len = urb->actual_length;
 303
 304                 if (len > sizeof(intr->read_regs.buffer))
 305                         len = sizeof(intr->read_regs.buffer);
 306                 memcpy(intr->read_regs.buffer, urb->transfer_buffer, len);
 307                 intr->read_regs_enabled = 0;
 308                 complete(&intr->read_regs.completion);
 309                 goto out;
 310         }
 311
 312         dev_dbg_f(urb_dev(urb), "regs interrupt ignored\n");
 313 out:
 314         spin_unlock(&intr->lock);
 315 }
 316
 317 static inline void handle_retry_failed_int(struct urb *urb)
 318 {
 319         struct zd_usb *usb = urb->context;
 320         struct zd_mac *mac = zd_usb_to_mac(usb);
 321         struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);
 322
 323         ieee->stats.tx_errors++;
 324         ieee->ieee_stats.tx_retry_limit_exceeded++;
 325         dev_dbg_f(urb_dev(urb), "retry failed interrupt\n");
 326 }
 327
 328
 329 static void int_urb_complete(struct urb *urb)
 330 {
 331         int r;
 332         struct usb_int_header *hdr;
 333
 334         switch (urb->status) {
 335         case 0:
 336                 break;
 337         case -ESHUTDOWN:
 338         case -EINVAL:
 339         case -ENODEV:
 340         case -ENOENT:
 341         case -ECONNRESET:
 342         case -EPIPE:
 343                 goto kfree;
 344         default:
 345                 goto resubmit;
 346         }
 347
 348         if (urb->actual_length < sizeof(hdr)) {
 349                 dev_dbg_f(urb_dev(urb), "error: urb %p to small\n", urb);
 350                 goto resubmit;
 351         }
 352
 353         hdr = urb->transfer_buffer;
 354         if (hdr->type != USB_INT_TYPE) {
 355                 dev_dbg_f(urb_dev(urb), "error: urb %p wrong type\n", urb);
 356                 goto resubmit;
 357         }
 358
 359         switch (hdr->id) {
 360         case USB_INT_ID_REGS:
 361                 handle_regs_int(urb);
 362                 break;
 363         case USB_INT_ID_RETRY_FAILED:
 364                 handle_retry_failed_int(urb);
 365                 break;
 366         default:
 367                 dev_dbg_f(urb_dev(urb), "error: urb %p unknown id %x\n", urb,
 368                         (unsigned int)hdr->id);
 369                 goto resubmit;
 370         }
 371
 372 resubmit:
 373         r = usb_submit_urb(urb, GFP_ATOMIC);
 374         if (r) {
 375                 dev_dbg_f(urb_dev(urb), "resubmit urb %p\n", urb);
 376                 goto kfree;
 377         }
 378         return;
 379 kfree:
 380         kfree(urb->transfer_buffer);
 381 }
 382
 383 static inline int int_urb_interval(struct usb_device *udev)
 384 {
 385         switch (udev->speed) {
 386         case USB_SPEED_HIGH:
 387                 return 4;
 388         case USB_SPEED_LOW:
 389                 return 10;
 390         case USB_SPEED_FULL:
 391         default:
 392                 return 1;
 393         }
 394 }
 395
 396 static inline int usb_int_enabled(struct zd_usb *usb)
 397 {
 398         unsigned long flags;
 399         struct zd_usb_interrupt *intr = &usb->intr;
 400         struct urb *urb;
 401
 402         spin_lock_irqsave(&intr->lock, flags);
 403         urb = intr->urb;
 404         spin_unlock_irqrestore(&intr->lock, flags);
 405         return urb != NULL;
 406 }
 407
 408 int zd_usb_enable_int(struct zd_usb *usb)
 409 {
 410         int r;
 411         struct usb_device *udev;
 412         struct zd_usb_interrupt *intr = &usb->intr;
 413         void *transfer_buffer = NULL;
 414         struct urb *urb;
 415
 416         dev_dbg_f(zd_usb_dev(usb), "\n");
 417
 418         urb = usb_alloc_urb(0, GFP_KERNEL);
 419         if (!urb) {
 420                 r = -ENOMEM;
 421                 goto out;
 422         }
 423
 424         ZD_ASSERT(!irqs_disabled());
 425         spin_lock_irq(&intr->lock);
 426         if (intr->urb) {
 427                 spin_unlock_irq(&intr->lock);
 428                 r = 0;
 429                 goto error_free_urb;
 430         }
 431         intr->urb = urb;
 432         spin_unlock_irq(&intr->lock);
 433
 434         /* TODO: make it a DMA buffer */
 435         r = -ENOMEM;
 436         transfer_buffer = kmalloc(USB_MAX_EP_INT_BUFFER, GFP_KERNEL);
 437         if (!transfer_buffer) {
 438                 dev_dbg_f(zd_usb_dev(usb),
 439                         "couldn't allocate transfer_buffer\n");
 440                 goto error_set_urb_null;
 441         }
 442
 443         udev = zd_usb_to_usbdev(usb);
 444         usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, EP_INT_IN),
 445                          transfer_buffer, USB_MAX_EP_INT_BUFFER,
 446                          int_urb_complete, usb,
 447                          intr->interval);
 448
 449         dev_dbg_f(zd_usb_dev(usb), "submit urb %p\n", intr->urb);
 450         r = usb_submit_urb(urb, GFP_KERNEL);
 451         if (r) {
 452                 dev_dbg_f(zd_usb_dev(usb),
 453                          "Couldn't submit urb. Error number %d\n", r);
 454                 goto error;
 455         }
 456
 457         return 0;
 458 error:
 459         kfree(transfer_buffer);
 460 error_set_urb_null:
 461         spin_lock_irq(&intr->lock);
 462         intr->urb = NULL;
 463         spin_unlock_irq(&intr->lock);
 464 error_free_urb:
 465         usb_free_urb(urb);
 466 out:
 467         return r;
 468 }
 469
 470 void zd_usb_disable_int(struct zd_usb *usb)
 471 {
 472         unsigned long flags;
 473         struct zd_usb_interrupt *intr = &usb->intr;
 474         struct urb *urb;
 475
 476         spin_lock_irqsave(&intr->lock, flags);
 477         urb = intr->urb;
 478         if (!urb) {
 479                 spin_unlock_irqrestore(&intr->lock, flags);
 480                 return;
 481         }
 482         intr->urb = NULL;
 483         spin_unlock_irqrestore(&intr->lock, flags);
 484
 485         usb_kill_urb(urb);
 486         dev_dbg_f(zd_usb_dev(usb), "urb %p killed\n", urb);
 487         usb_free_urb(urb);
 488 }
 489
 490 static void handle_rx_packet(struct zd_usb *usb, const u8 *buffer,
 491                              unsigned int length)
 492 {
 493         int i;
 494         struct zd_mac *mac = zd_usb_to_mac(usb);
 495         const struct rx_length_info *length_info;
 496
 497         if (length < sizeof(struct rx_length_info)) {
 498                 /* It's not a complete packet anyhow. */
 499                 struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);
 500                 ieee->stats.rx_errors++;
 501                 ieee->stats.rx_length_errors++;
 502                 return;
 503         }
 504         length_info = (struct rx_length_info *)
 505                 (buffer + length - sizeof(struct rx_length_info));
 506
 507         /* It might be that three frames are merged into a single URB
 508          * transaction. We have to check for the length info tag.
 509          *
 510          * While testing we discovered that length_info might be unaligned,
 511          * because if USB transactions are merged, the last packet will not
 512          * be padded. Unaligned access might also happen if the length_info
 513          * structure is not present.
 514          */
 515         if (get_unaligned(&length_info->tag) == cpu_to_le16(RX_LENGTH_INFO_TAG))
 516         {
 517                 unsigned int l, k, n;
 518                 for (i = 0, l = 0;; i++) {
 519                         k = le16_to_cpu(get_unaligned(&length_info->length[i]));
 520                         if (k == 0)
 521                                 return;
 522                         n = l+k;
 523                         if (n > length)
 524                                 return;
 525                         zd_mac_rx_irq(mac, buffer+l, k);
 526                         if (i >= 2)
 527                                 return;
 528                         l = (n+3) & ~3;
 529                 }
 530         } else {
 531                 zd_mac_rx_irq(mac, buffer, length);
 532         }
 533 }
 534
 535 static void rx_urb_complete(struct urb *urb)
 536 {
 537         struct zd_usb *usb;
 538         struct zd_usb_rx *rx;
 539         const u8 *buffer;
 540         unsigned int length;
 541
 542         switch (urb->status) {
 543         case 0:
 544                 break;
 545         case -ESHUTDOWN:
 546         case -EINVAL:
 547         case -ENODEV:
 548         case -ENOENT:
 549         case -ECONNRESET:
 550         case -EPIPE:
 551                 return;
 552         default:
 553                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 554                 goto resubmit;
 555         }
 556
 557         buffer = urb->transfer_buffer;
 558         length = urb->actual_length;
 559         usb = urb->context;
 560         rx = &usb->rx;
 561
 562         if (length%rx->usb_packet_size > rx->usb_packet_size-4) {
 563                 /* If there is an old first fragment, we don't care. */
 564                 dev_dbg_f(urb_dev(urb), "*** first fragment ***\n");
 565                 ZD_ASSERT(length <= ARRAY_SIZE(rx->fragment));
 566                 spin_lock(&rx->lock);
 567                 memcpy(rx->fragment, buffer, length);
 568                 rx->fragment_length = length;
 569                 spin_unlock(&rx->lock);
 570                 goto resubmit;
 571         }
 572
 573         spin_lock(&rx->lock);
 574         if (rx->fragment_length > 0) {
 575                 /* We are on a second fragment, we believe */
 576                 ZD_ASSERT(length + rx->fragment_length <=
 577                           ARRAY_SIZE(rx->fragment));
 578                 dev_dbg_f(urb_dev(urb), "*** second fragment ***\n");
 579                 memcpy(rx->fragment+rx->fragment_length, buffer, length);
 580                 handle_rx_packet(usb, rx->fragment,
 581                                  rx->fragment_length + length);
 582                 rx->fragment_length = 0;
 583                 spin_unlock(&rx->lock);
 584         } else {
 585                 spin_unlock(&rx->lock);
 586                 handle_rx_packet(usb, buffer, length);
 587         }
 588
 589 resubmit:
 590         usb_submit_urb(urb, GFP_ATOMIC);
 591 }
 592
 593 static struct urb *alloc_urb(struct zd_usb *usb)
 594 {
 595         struct usb_device *udev = zd_usb_to_usbdev(usb);
 596         struct urb *urb;
 597         void *buffer;
 598
 599         urb = usb_alloc_urb(0, GFP_KERNEL);
 600         if (!urb)
 601                 return NULL;
 602         buffer = usb_buffer_alloc(udev, USB_MAX_RX_SIZE, GFP_KERNEL,
 603                                   &urb->transfer_dma);
 604         if (!buffer) {
 605                 usb_free_urb(urb);
 606                 return NULL;
 607         }
 608
 609         usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_DATA_IN),
 610                           buffer, USB_MAX_RX_SIZE,
 611                           rx_urb_complete, usb);
 612         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 613
 614         return urb;
 615 }
 616
 617 static void free_urb(struct urb *urb)
 618 {
 619         if (!urb)
 620                 return;
 621         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 622                         urb->transfer_buffer, urb->transfer_dma);
 623         usb_free_urb(urb);
 624 }
 625
 626 int zd_usb_enable_rx(struct zd_usb *usb)
 627 {
 628         int i, r;
 629         struct zd_usb_rx *rx = &usb->rx;
 630         struct urb **urbs;
 631
 632         dev_dbg_f(zd_usb_dev(usb), "\n");
 633
 634         r = -ENOMEM;
 635         urbs = kcalloc(URBS_COUNT, sizeof(struct urb *), GFP_KERNEL);
 636         if (!urbs)
 637                 goto error;
 638         for (i = 0; i < URBS_COUNT; i++) {
 639                 urbs[i] = alloc_urb(usb);
 640                 if (!urbs[i])
 641                         goto error;
 642         }
 643
 644         ZD_ASSERT(!irqs_disabled());
 645         spin_lock_irq(&rx->lock);
 646         if (rx->urbs) {
 647                 spin_unlock_irq(&rx->lock);
 648                 r = 0;
 649                 goto error;
 650         }
 651         rx->urbs = urbs;
 652         rx->urbs_count = URBS_COUNT;
 653         spin_unlock_irq(&rx->lock);
 654
 655         for (i = 0; i < URBS_COUNT; i++) {
 656                 r = usb_submit_urb(urbs[i], GFP_KERNEL);
 657                 if (r)
 658                         goto error_submit;
 659         }
 660
 661         return 0;
 662 error_submit:
 663         for (i = 0; i < URBS_COUNT; i++) {
 664                 usb_kill_urb(urbs[i]);
 665         }
 666         spin_lock_irq(&rx->lock);
 667         rx->urbs = NULL;
 668         rx->urbs_count = 0;
 669         spin_unlock_irq(&rx->lock);
 670 error:
 671         if (urbs) {
 672                 for (i = 0; i < URBS_COUNT; i++)
 673                         free_urb(urbs[i]);
 674         }
 675         return r;
 676 }
 677
 678 void zd_usb_disable_rx(struct zd_usb *usb)
 679 {
 680         int i;
 681         unsigned long flags;
 682         struct urb **urbs;
 683         unsigned int count;
 684         struct zd_usb_rx *rx = &usb->rx;
 685
 686         spin_lock_irqsave(&rx->lock, flags);
 687         urbs = rx->urbs;
 688         count = rx->urbs_count;
 689         spin_unlock_irqrestore(&rx->lock, flags);
 690         if (!urbs)
 691                 return;
 692
 693         for (i = 0; i < count; i++) {
 694                 usb_kill_urb(urbs[i]);
 695                 free_urb(urbs[i]);
 696         }
 697         kfree(urbs);
 698
 699         spin_lock_irqsave(&rx->lock, flags);
 700         rx->urbs = NULL;
 701         rx->urbs_count = 0;
 702         spin_unlock_irqrestore(&rx->lock, flags);
 703 }
 704
 705 static void tx_urb_complete(struct urb *urb)
 706 {
 707         int r;
 708
 709         switch (urb->status) {
 710         case 0:
 711                 break;
 712         case -ESHUTDOWN:
 713         case -EINVAL:
 714         case -ENODEV:
 715         case -ENOENT:
 716         case -ECONNRESET:
 717         case -EPIPE:
 718                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 719                 break;
 720         default:
 721                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 722                 goto resubmit;
 723         }
 724 free_urb:
 725         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 726                         urb->transfer_buffer, urb->transfer_dma);
 727         usb_free_urb(urb);
 728         return;
 729 resubmit:
 730         r = usb_submit_urb(urb, GFP_ATOMIC);
 731         if (r) {
 732                 dev_dbg_f(urb_dev(urb), "error resubmit urb %p %d\n", urb, r);
 733                 goto free_urb;
 734         }
 735 }
 736
 737 /* Puts the frame on the USB endpoint. It doesn't wait for
 738  * completion. The frame must contain the control set.
 739  */
 740 int zd_usb_tx(struct zd_usb *usb, const u8 *frame, unsigned int length)
 741 {
 742         int r;
 743         struct usb_device *udev = zd_usb_to_usbdev(usb);
 744         struct urb *urb;
 745         void *buffer;
 746
 747         urb = usb_alloc_urb(0, GFP_ATOMIC);
 748         if (!urb) {
 749                 r = -ENOMEM;
 750                 goto out;
 751         }
 752
 753         buffer = usb_buffer_alloc(zd_usb_to_usbdev(usb), length, GFP_ATOMIC,
 754                                   &urb->transfer_dma);
 755         if (!buffer) {
 756                 r = -ENOMEM;
 757                 goto error_free_urb;
 758         }
 759         memcpy(buffer, frame, length);
 760
 761         usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, EP_DATA_OUT),
 762                           buffer, length, tx_urb_complete, NULL);
 763         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 764
 765         r = usb_submit_urb(urb, GFP_ATOMIC);
 766         if (r)
 767                 goto error;
 768         return 0;
 769 error:
 770         usb_buffer_free(zd_usb_to_usbdev(usb), length, buffer,
 771                         urb->transfer_dma);
 772 error_free_urb:
 773         usb_free_urb(urb);
 774 out:
 775         return r;
 776 }
 777
 778 static inline void init_usb_interrupt(struct zd_usb *usb)
 779 {
 780         struct zd_usb_interrupt *intr = &usb->intr;
 781
 782         spin_lock_init(&intr->lock);
 783         intr->interval = int_urb_interval(zd_usb_to_usbdev(usb));
 784         init_completion(&intr->read_regs.completion);
 785         intr->read_regs.cr_int_addr = cpu_to_le16((u16)CR_INTERRUPT);
 786 }
 787
 788 static inline void init_usb_rx(struct zd_usb *usb)
 789 {
 790         struct zd_usb_rx *rx = &usb->rx;
 791         spin_lock_init(&rx->lock);
 792         if (interface_to_usbdev(usb->intf)->speed == USB_SPEED_HIGH) {
 793                 rx->usb_packet_size = 512;
 794         } else {
 795                 rx->usb_packet_size = 64;
 796         }
 797         ZD_ASSERT(rx->fragment_length == 0);
 798 }
 799
 800 static inline void init_usb_tx(struct zd_usb *usb)
 801 {
 802         /* FIXME: at this point we will allocate a fixed number of urb's for
 803          * use in a cyclic scheme */
 804 }
 805
 806 void zd_usb_init(struct zd_usb *usb, struct net_device *netdev,
 807                  struct usb_interface *intf)
 808 {
 809         memset(usb, 0, sizeof(*usb));
 810         usb->intf = usb_get_intf(intf);
 811         usb_set_intfdata(usb->intf, netdev);
 812         init_usb_interrupt(usb);
 813         init_usb_tx(usb);
 814         init_usb_rx(usb);
 815 }
 816
 817 void zd_usb_clear(struct zd_usb *usb)
 818 {
 819         usb_set_intfdata(usb->intf, NULL);
 820         usb_put_intf(usb->intf);
 821         ZD_MEMCLEAR(usb, sizeof(*usb));
 822         /* FIXME: usb_interrupt, usb_tx, usb_rx? */
 823 }
 824
 825 static const char *speed(enum usb_device_speed speed)
 826 {
 827         switch (speed) {
 828         case USB_SPEED_LOW:
 829                 return "low";
 830         case USB_SPEED_FULL:
 831                 return "full";
 832         case USB_SPEED_HIGH:
 833                 return "high";
 834         default:
 835                 return "unknown speed";
 836         }
 837 }
 838
 839 static int scnprint_id(struct usb_device *udev, char *buffer, size_t size)
 840 {
 841         return scnprintf(buffer, size, "%04hx:%04hx v%04hx %s",
 842                 le16_to_cpu(udev->descriptor.idVendor),
 843                 le16_to_cpu(udev->descriptor.idProduct),
 844                 get_bcdDevice(udev),
 845                 speed(udev->speed));
 846 }
 847
 848 int zd_usb_scnprint_id(struct zd_usb *usb, char *buffer, size_t size)
 849 {
 850         struct usb_device *udev = interface_to_usbdev(usb->intf);
 851         return scnprint_id(udev, buffer, size);
 852 }
 853
 854 #ifdef DEBUG
 855 static void print_id(struct usb_device *udev)
 856 {
 857         char buffer[40];
 858
 859         scnprint_id(udev, buffer, sizeof(buffer));
 860         buffer[sizeof(buffer)-1] = 0;
 861         dev_dbg_f(&udev->dev, "%s\n", buffer);
 862 }
 863 #else
 864 #define print_id(udev) do { } while (0)
 865 #endif
 866
 867 static int eject_installer(struct usb_interface *intf)
 868 {
 869         struct usb_device *udev = interface_to_usbdev(intf);
 870         struct usb_host_interface *iface_desc = &intf->altsetting[0];
 871         struct usb_endpoint_descriptor *endpoint;
 872         unsigned char *cmd;
 873         u8 bulk_out_ep;
 874         int r;
 875
 876         /* Find bulk out endpoint */
 877         endpoint = &iface_desc->endpoint[1].desc;
 878         if ((endpoint->bEndpointAddress & USB_TYPE_MASK) == USB_DIR_OUT &&
 879             (endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
 880             USB_ENDPOINT_XFER_BULK) {
 881                 bulk_out_ep = endpoint->bEndpointAddress;
 882         } else {
 883                 dev_err(&udev->dev,
 884                         "zd1211rw: Could not find bulk out endpoint\n");
 885                 return -ENODEV;
 886         }
 887
 888         cmd = kzalloc(31, GFP_KERNEL);
 889         if (cmd == NULL)
 890                 return -ENODEV;
 891
 892         /* USB bulk command block */
 893         cmd[0] = 0x55;  /* bulk command signature */
 894         cmd[1] = 0x53;  /* bulk command signature */
 895         cmd[2] = 0x42;  /* bulk command signature */
 896         cmd[3] = 0x43;  /* bulk command signature */
 897         cmd[14] = 6;    /* command length */
 898
 899         cmd[15] = 0x1b; /* SCSI command: START STOP UNIT */
 900         cmd[19] = 0x2;  /* eject disc */
 901
 902         dev_info(&udev->dev, "Ejecting virtual installer media...\n");
 903         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, bulk_out_ep),
 904                 cmd, 31, NULL, 2000);
 905         kfree(cmd);
 906         if (r)
 907                 return r;
 908
 909         /* At this point, the device disconnects and reconnects with the real
 910          * ID numbers. */
 911
 912         usb_set_intfdata(intf, NULL);
 913         return 0;
 914 }
 915
 916 static int probe(struct usb_interface *intf, const struct usb_device_id *id)
 917 {
 918         int r;
 919         struct usb_device *udev = interface_to_usbdev(intf);
 920         struct net_device *netdev = NULL;
 921
 922         print_id(udev);
 923
 924         if (id->driver_info & DEVICE_INSTALLER)
 925                 return eject_installer(intf);
 926
 927         switch (udev->speed) {
 928         case USB_SPEED_LOW:
 929         case USB_SPEED_FULL:
 930         case USB_SPEED_HIGH:
 931                 break;
 932         default:
 933                 dev_dbg_f(&intf->dev, "Unknown USB speed\n");
 934                 r = -ENODEV;
 935                 goto error;
 936         }
 937
 938         usb_reset_device(interface_to_usbdev(intf));
 939
 940         netdev = zd_netdev_alloc(intf);
 941         if (netdev == NULL) {
 942                 r = -ENOMEM;
 943                 goto error;
 944         }
 945
 946         r = upload_firmware(udev, id->driver_info);
 947         if (r) {
 948                 dev_err(&intf->dev,
 949                        "couldn't load firmware. Error number %d\n", r);
 950                 goto error;
 951         }
 952
 953         r = usb_reset_configuration(udev);
 954         if (r) {
 955                 dev_dbg_f(&intf->dev,
 956                         "couldn't reset configuration. Error number %d\n", r);
 957                 goto error;
 958         }
 959
 960         /* At this point the interrupt endpoint is not generally enabled. We
 961          * save the USB bandwidth until the network device is opened. But
 962          * notify that the initialization of the MAC will require the
 963          * interrupts to be temporary enabled.
 964          */
 965         r = zd_mac_init_hw(zd_netdev_mac(netdev), id->driver_info);
 966         if (r) {
 967                 dev_dbg_f(&intf->dev,
 968                          "couldn't initialize mac. Error number %d\n", r);
 969                 goto error;
 970         }
 971
 972         r = register_netdev(netdev);
 973         if (r) {
 974                 dev_dbg_f(&intf->dev,
 975                          "couldn't register netdev. Error number %d\n", r);
 976                 goto error;
 977         }
 978
 979         dev_dbg_f(&intf->dev, "successful\n");
 980         dev_info(&intf->dev,"%s\n", netdev->name);
 981         return 0;
 982 error:
 983         usb_reset_device(interface_to_usbdev(intf));
 984         zd_netdev_free(netdev);
 985         return r;
 986 }
 987
 988 static void disconnect(struct usb_interface *intf)
 989 {
 990         struct net_device *netdev = zd_intf_to_netdev(intf);
 991         struct zd_mac *mac = zd_netdev_mac(netdev);
 992         struct zd_usb *usb = &mac->chip.usb;
 993
 994         /* Either something really bad happened, or we're just dealing with
 995          * a DEVICE_INSTALLER. */
 996         if (netdev == NULL)
 997                 return;
 998
 999         dev_dbg_f(zd_usb_dev(usb), "\n");
1000
1001         zd_netdev_disconnect(netdev);
1002
1003         /* Just in case something has gone wrong! */
1004         zd_usb_disable_rx(usb);
1005         zd_usb_disable_int(usb);
1006
1007         /* If the disconnect has been caused by a removal of the
1008          * driver module, the reset allows reloading of the driver. If the
1009          * reset will not be executed here, the upload of the firmware in the
1010          * probe function caused by the reloading of the driver will fail.
1011          */
1012         usb_reset_device(interface_to_usbdev(intf));
1013
1014         zd_netdev_free(netdev);
1015         dev_dbg(&intf->dev, "disconnected\n");
1016 }
1017
1018 static struct usb_driver driver = {
1019         .name           = "zd1211rw",
1020         .id_table       = usb_ids,
1021         .probe          = probe,
1022         .disconnect     = disconnect,
1023 };
1024
1025 struct workqueue_struct *zd_workqueue;
1026
1027 static int __init usb_init(void)
1028 {
1029         int r;
1030
1031         pr_debug("%s usb_init()\n", driver.name);
1032
1033         zd_workqueue = create_singlethread_workqueue(driver.name);
1034         if (zd_workqueue == NULL) {
1035                 printk(KERN_ERR "%s couldn't create workqueue\n", driver.name);
1036                 return -ENOMEM;
1037         }
1038
1039         r = usb_register(&driver);
1040         if (r) {
1041                 destroy_workqueue(zd_workqueue);
1042                 printk(KERN_ERR "%s usb_register() failed. Error number %d\n",
1043                        driver.name, r);
1044                 return r;
1045         }
1046
1047         pr_debug("%s initialized\n", driver.name);
1048         return 0;
1049 }
1050
1051 static void __exit usb_exit(void)
1052 {
1053         pr_debug("%s usb_exit()\n", driver.name);
1054         usb_deregister(&driver);
1055         destroy_workqueue(zd_workqueue);
1056 }
1057
1058 module_init(usb_init);
1059 module_exit(usb_exit);
1060
1061 static int usb_int_regs_length(unsigned int count)
1062 {
1063         return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data);
1064 }
1065
1066 static void prepare_read_regs_int(struct zd_usb *usb)
1067 {
1068         struct zd_usb_interrupt *intr = &usb->intr;
1069
1070         spin_lock_irq(&intr->lock);
1071         intr->read_regs_enabled = 1;
1072         INIT_COMPLETION(intr->read_regs.completion);
1073         spin_unlock_irq(&intr->lock);
1074 }
1075
1076 static void disable_read_regs_int(struct zd_usb *usb)
1077 {
1078         struct zd_usb_interrupt *intr = &usb->intr;
1079
1080         spin_lock_irq(&intr->lock);
1081         intr->read_regs_enabled = 0;
1082         spin_unlock_irq(&intr->lock);
1083 }
1084
1085 static int get_results(struct zd_usb *usb, u16 *values,
1086                        struct usb_req_read_regs *req, unsigned int count)
1087 {
1088         int r;
1089         int i;
1090         struct zd_usb_interrupt *intr = &usb->intr;
1091         struct read_regs_int *rr = &intr->read_regs;
1092         struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
1093
1094         spin_lock_irq(&intr->lock);
1095
1096         r = -EIO;
1097         /* The created block size seems to be larger than expected.
1098          * However results appear to be correct.
1099          */
1100         if (rr->length < usb_int_regs_length(count)) {
1101                 dev_dbg_f(zd_usb_dev(usb),
1102                          "error: actual length %d less than expected %d\n",
1103                          rr->length, usb_int_regs_length(count));
1104                 goto error_unlock;
1105         }
1106         if (rr->length > sizeof(rr->buffer)) {
1107                 dev_dbg_f(zd_usb_dev(usb),
1108                          "error: actual length %d exceeds buffer size %zu\n",
1109                          rr->length, sizeof(rr->buffer));
1110                 goto error_unlock;
1111         }
1112
1113         for (i = 0; i < count; i++) {
1114                 struct reg_data *rd = &regs->regs[i];
1115                 if (rd->addr != req->addr[i]) {
1116                         dev_dbg_f(zd_usb_dev(usb),
1117                                  "rd[%d] addr %#06hx expected %#06hx\n", i,
1118                                  le16_to_cpu(rd->addr),
1119                                  le16_to_cpu(req->addr[i]));
1120                         goto error_unlock;
1121                 }
1122                 values[i] = le16_to_cpu(rd->value);
1123         }
1124
1125         r = 0;
1126 error_unlock:
1127         spin_unlock_irq(&intr->lock);
1128         return r;
1129 }
1130
1131 int zd_usb_ioread16v(struct zd_usb *usb, u16 *values,
1132                      const zd_addr_t *addresses, unsigned int count)
1133 {
1134         int r;
1135         int i, req_len, actual_req_len;
1136         struct usb_device *udev;
1137         struct usb_req_read_regs *req = NULL;
1138         unsigned long timeout;
1139
1140         if (count < 1) {
1141                 dev_dbg_f(zd_usb_dev(usb), "error: count is zero\n");
1142                 return -EINVAL;
1143         }
1144         if (count > USB_MAX_IOREAD16_COUNT) {
1145                 dev_dbg_f(zd_usb_dev(usb),
1146                          "error: count %u exceeds possible max %u\n",
1147                          count, USB_MAX_IOREAD16_COUNT);
1148                 return -EINVAL;
1149         }
1150         if (in_atomic()) {
1151                 dev_dbg_f(zd_usb_dev(usb),
1152                          "error: io in atomic context not supported\n");
1153                 return -EWOULDBLOCK;
1154         }
1155         if (!usb_int_enabled(usb)) {
1156                  dev_dbg_f(zd_usb_dev(usb),
1157                           "error: usb interrupt not enabled\n");
1158                 return -EWOULDBLOCK;
1159         }
1160
1161         req_len = sizeof(struct usb_req_read_regs) + count * sizeof(__le16);
1162         req = kmalloc(req_len, GFP_KERNEL);
1163         if (!req)
1164                 return -ENOMEM;
1165         req->id = cpu_to_le16(USB_REQ_READ_REGS);
1166         for (i = 0; i < count; i++)
1167                 req->addr[i] = cpu_to_le16((u16)addresses[i]);
1168
1169         udev = zd_usb_to_usbdev(usb);
1170         prepare_read_regs_int(usb);
1171         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1172                          req, req_len, &actual_req_len, 1000 /* ms */);
1173         if (r) {
1174                 dev_dbg_f(zd_usb_dev(usb),
1175                         "error in usb_bulk_msg(). Error number %d\n", r);
1176                 goto error;
1177         }
1178         if (req_len != actual_req_len) {
1179                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()\n"
1180                         " req_len %d != actual_req_len %d\n",
1181                         req_len, actual_req_len);
1182                 r = -EIO;
1183                 goto error;
1184         }
1185
1186         timeout = wait_for_completion_timeout(&usb->intr.read_regs.completion,
1187                                               msecs_to_jiffies(1000));
1188         if (!timeout) {
1189                 disable_read_regs_int(usb);
1190                 dev_dbg_f(zd_usb_dev(usb), "read timed out\n");
1191                 r = -ETIMEDOUT;
1192                 goto error;
1193         }
1194
1195         r = get_results(usb, values, req, count);
1196 error:
1197         kfree(req);
1198         return r;
1199 }
1200
1201 int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
1202                       unsigned int count)
1203 {
1204         int r;
1205         struct usb_device *udev;
1206         struct usb_req_write_regs *req = NULL;
1207         int i, req_len, actual_req_len;
1208
1209         if (count == 0)
1210                 return 0;
1211         if (count > USB_MAX_IOWRITE16_COUNT) {
1212                 dev_dbg_f(zd_usb_dev(usb),
1213                         "error: count %u exceeds possible max %u\n",
1214                         count, USB_MAX_IOWRITE16_COUNT);
1215                 return -EINVAL;
1216         }
1217         if (in_atomic()) {
1218                 dev_dbg_f(zd_usb_dev(usb),
1219                         "error: io in atomic context not supported\n");
1220                 return -EWOULDBLOCK;
1221         }
1222
1223         req_len = sizeof(struct usb_req_write_regs) +
1224                   count * sizeof(struct reg_data);
1225         req = kmalloc(req_len, GFP_KERNEL);
1226         if (!req)
1227                 return -ENOMEM;
1228
1229         req->id = cpu_to_le16(USB_REQ_WRITE_REGS);
1230         for (i = 0; i < count; i++) {
1231                 struct reg_data *rw  = &req->reg_writes[i];
1232                 rw->addr = cpu_to_le16((u16)ioreqs[i].addr);
1233                 rw->value = cpu_to_le16(ioreqs[i].value);
1234         }
1235
1236         udev = zd_usb_to_usbdev(usb);
1237         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1238                          req, req_len, &actual_req_len, 1000 /* ms */);
1239         if (r) {
1240                 dev_dbg_f(zd_usb_dev(usb),
1241                         "error in usb_bulk_msg(). Error number %d\n", r);
1242                 goto error;
1243         }
1244         if (req_len != actual_req_len) {
1245                 dev_dbg_f(zd_usb_dev(usb),
1246                         "error in usb_bulk_msg()"
1247                         " req_len %d != actual_req_len %d\n",
1248                         req_len, actual_req_len);
1249                 r = -EIO;
1250                 goto error;
1251         }
1252
1253         /* FALL-THROUGH with r == 0 */
1254 error:
1255         kfree(req);
1256         return r;
1257 }
1258
1259 int zd_usb_rfwrite(struct zd_usb *usb, u32 value, u8 bits)
1260 {
1261         int r;
1262         struct usb_device *udev;
1263         struct usb_req_rfwrite *req = NULL;
1264         int i, req_len, actual_req_len;
1265         u16 bit_value_template;
1266
1267         if (in_atomic()) {
1268                 dev_dbg_f(zd_usb_dev(usb),
1269                         "error: io in atomic context not supported\n");
1270                 return -EWOULDBLOCK;
1271         }
1272         if (bits < USB_MIN_RFWRITE_BIT_COUNT) {
1273                 dev_dbg_f(zd_usb_dev(usb),
1274                         "error: bits %d are smaller than"
1275                         " USB_MIN_RFWRITE_BIT_COUNT %d\n",
1276                         bits, USB_MIN_RFWRITE_BIT_COUNT);
1277                 return -EINVAL;
1278         }
1279         if (bits > USB_MAX_RFWRITE_BIT_COUNT) {
1280                 dev_dbg_f(zd_usb_dev(usb),
1281                         "error: bits %d exceed USB_MAX_RFWRITE_BIT_COUNT %d\n",
1282                         bits, USB_MAX_RFWRITE_BIT_COUNT);
1283                 return -EINVAL;
1284         }
1285 #ifdef DEBUG
1286         if (value & (~0UL << bits)) {
1287                 dev_dbg_f(zd_usb_dev(usb),
1288                         "error: value %#09x has bits >= %d set\n",
1289                         value, bits);
1290                 return -EINVAL;
1291         }
1292 #endif /* DEBUG */
1293
1294         dev_dbg_f(zd_usb_dev(usb), "value %#09x bits %d\n", value, bits);
1295
1296         r = zd_usb_ioread16(usb, &bit_value_template, CR203);
1297         if (r) {
1298                 dev_dbg_f(zd_usb_dev(usb),
1299                         "error %d: Couldn't read CR203\n", r);
1300                 goto out;
1301         }
1302         bit_value_template &= ~(RF_IF_LE|RF_CLK|RF_DATA);
1303
1304         req_len = sizeof(struct usb_req_rfwrite) + bits * sizeof(__le16);
1305         req = kmalloc(req_len, GFP_KERNEL);
1306         if (!req)
1307                 return -ENOMEM;
1308
1309         req->id = cpu_to_le16(USB_REQ_WRITE_RF);
1310         /* 1: 3683a, but not used in ZYDAS driver */
1311         req->value = cpu_to_le16(2);
1312         req->bits = cpu_to_le16(bits);
1313
1314         for (i = 0; i < bits; i++) {
1315                 u16 bv = bit_value_template;
1316                 if (value & (1 << (bits-1-i)))
1317                         bv |= RF_DATA;
1318                 req->bit_values[i] = cpu_to_le16(bv);
1319         }
1320
1321         udev = zd_usb_to_usbdev(usb);
1322         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1323                          req, req_len, &actual_req_len, 1000 /* ms */);
1324         if (r) {
1325                 dev_dbg_f(zd_usb_dev(usb),
1326                         "error in usb_bulk_msg(). Error number %d\n", r);
1327                 goto out;
1328         }
1329         if (req_len != actual_req_len) {
1330                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()"
1331                         " req_len %d != actual_req_len %d\n",
1332                         req_len, actual_req_len);
1333                 r = -EIO;
1334                 goto out;
1335         }
1336
1337         /* FALL-THROUGH with r == 0 */
1338 out:
1339         kfree(req);
1340         return r;
1341 }