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(0x0df6, 0x9075), .driver_info = DEVICE_ZD1211 },
  44         { USB_DEVICE(0x157e, 0x300b), .driver_info = DEVICE_ZD1211 },
  45         { USB_DEVICE(0x079b, 0x004a), .driver_info = DEVICE_ZD1211 },
  46         { USB_DEVICE(0x1740, 0x2000), .driver_info = DEVICE_ZD1211 },
  47         { USB_DEVICE(0x157e, 0x3204), .driver_info = DEVICE_ZD1211 },
  48         { USB_DEVICE(0x0586, 0x3402), .driver_info = DEVICE_ZD1211 },
  49         { USB_DEVICE(0x0b3b, 0x5630), .driver_info = DEVICE_ZD1211 },
  50         { USB_DEVICE(0x0b05, 0x170c), .driver_info = DEVICE_ZD1211 },
  51         { USB_DEVICE(0x1435, 0x0711), .driver_info = DEVICE_ZD1211 },
  52         { USB_DEVICE(0x0586, 0x3409), .driver_info = DEVICE_ZD1211 },
  53         { USB_DEVICE(0x0b3b, 0x1630), .driver_info = DEVICE_ZD1211 },
  54         { USB_DEVICE(0x0586, 0x3401), .driver_info = DEVICE_ZD1211 },
  55         { USB_DEVICE(0x14ea, 0xab13), .driver_info = DEVICE_ZD1211 },
  56         { USB_DEVICE(0x13b1, 0x001e), .driver_info = DEVICE_ZD1211 },
  57         { USB_DEVICE(0x0586, 0x3407), .driver_info = DEVICE_ZD1211 },
  58         /* ZD1211B */
  59         { USB_DEVICE(0x0ace, 0x1215), .driver_info = DEVICE_ZD1211B },
  60         { USB_DEVICE(0x157e, 0x300d), .driver_info = DEVICE_ZD1211B },
  61         { USB_DEVICE(0x079b, 0x0062), .driver_info = DEVICE_ZD1211B },
  62         { USB_DEVICE(0x1582, 0x6003), .driver_info = DEVICE_ZD1211B },
  63         { USB_DEVICE(0x050d, 0x705c), .driver_info = DEVICE_ZD1211B },
  64         { USB_DEVICE(0x083a, 0x4505), .driver_info = DEVICE_ZD1211B },
  65         { USB_DEVICE(0x0471, 0x1236), .driver_info = DEVICE_ZD1211B },
  66         { USB_DEVICE(0x13b1, 0x0024), .driver_info = DEVICE_ZD1211B },
  67         { USB_DEVICE(0x0586, 0x340f), .driver_info = DEVICE_ZD1211B },
  68         { USB_DEVICE(0x0b05, 0x171b), .driver_info = DEVICE_ZD1211B },
  69         { USB_DEVICE(0x0586, 0x3410), .driver_info = DEVICE_ZD1211B },
  70         { USB_DEVICE(0x0baf, 0x0121), .driver_info = DEVICE_ZD1211B },
  71         { USB_DEVICE(0x0586, 0x3412), .driver_info = DEVICE_ZD1211B },
  72         { USB_DEVICE(0x0586, 0x3413), .driver_info = DEVICE_ZD1211B },
  73         { USB_DEVICE(0x0053, 0x5301), .driver_info = DEVICE_ZD1211B },
  74         { USB_DEVICE(0x0411, 0x00da), .driver_info = DEVICE_ZD1211B },
  75         /* "Driverless" devices that need ejecting */
  76         { USB_DEVICE(0x0ace, 0x2011), .driver_info = DEVICE_INSTALLER },
  77         { USB_DEVICE(0x0ace, 0x20ff), .driver_info = DEVICE_INSTALLER },
  78         {}
  79 };
  80
  81 MODULE_LICENSE("GPL");
  82 MODULE_DESCRIPTION("USB driver for devices with the ZD1211 chip.");
  83 MODULE_AUTHOR("Ulrich Kunitz");
  84 MODULE_AUTHOR("Daniel Drake");
  85 MODULE_VERSION("1.0");
  86 MODULE_DEVICE_TABLE(usb, usb_ids);
  87
  88 #define FW_ZD1211_PREFIX        "zd1211/zd1211_"
  89 #define FW_ZD1211B_PREFIX       "zd1211/zd1211b_"
  90
  91 /* USB device initialization */
  92
  93 static int request_fw_file(
  94         const struct firmware **fw, const char *name, struct device *device)
  95 {
  96         int r;
  97
  98         dev_dbg_f(device, "fw name %s\n", name);
  99
 100         r = request_firmware(fw, name, device);
 101         if (r)
 102                 dev_err(device,
 103                        "Could not load firmware file %s. Error number %d\n",
 104                        name, r);
 105         return r;
 106 }
 107
 108 static inline u16 get_bcdDevice(const struct usb_device *udev)
 109 {
 110         return le16_to_cpu(udev->descriptor.bcdDevice);
 111 }
 112
 113 enum upload_code_flags {
 114         REBOOT = 1,
 115 };
 116
 117 /* Ensures that MAX_TRANSFER_SIZE is even. */
 118 #define MAX_TRANSFER_SIZE (USB_MAX_TRANSFER_SIZE & ~1)
 119
 120 static int upload_code(struct usb_device *udev,
 121         const u8 *data, size_t size, u16 code_offset, int flags)
 122 {
 123         u8 *p;
 124         int r;
 125
 126         /* USB request blocks need "kmalloced" buffers.
 127          */
 128         p = kmalloc(MAX_TRANSFER_SIZE, GFP_KERNEL);
 129         if (!p) {
 130                 dev_err(&udev->dev, "out of memory\n");
 131                 r = -ENOMEM;
 132                 goto error;
 133         }
 134
 135         size &= ~1;
 136         while (size > 0) {
 137                 size_t transfer_size = size <= MAX_TRANSFER_SIZE ?
 138                         size : MAX_TRANSFER_SIZE;
 139
 140                 dev_dbg_f(&udev->dev, "transfer size %zu\n", transfer_size);
 141
 142                 memcpy(p, data, transfer_size);
 143                 r = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 144                         USB_REQ_FIRMWARE_DOWNLOAD,
 145                         USB_DIR_OUT | USB_TYPE_VENDOR,
 146                         code_offset, 0, p, transfer_size, 1000 /* ms */);
 147                 if (r < 0) {
 148                         dev_err(&udev->dev,
 149                                "USB control request for firmware upload"
 150                                " failed. Error number %d\n", r);
 151                         goto error;
 152                 }
 153                 transfer_size = r & ~1;
 154
 155                 size -= transfer_size;
 156                 data += transfer_size;
 157                 code_offset += transfer_size/sizeof(u16);
 158         }
 159
 160         if (flags & REBOOT) {
 161                 u8 ret;
 162
 163                 r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
 164                         USB_REQ_FIRMWARE_CONFIRM,
 165                         USB_DIR_IN | USB_TYPE_VENDOR,
 166                         0, 0, &ret, sizeof(ret), 5000 /* ms */);
 167                 if (r != sizeof(ret)) {
 168                         dev_err(&udev->dev,
 169                                 "control request firmeware confirmation failed."
 170                                 " Return value %d\n", r);
 171                         if (r >= 0)
 172                                 r = -ENODEV;
 173                         goto error;
 174                 }
 175                 if (ret & 0x80) {
 176                         dev_err(&udev->dev,
 177                                 "Internal error while downloading."
 178                                 " Firmware confirm return value %#04x\n",
 179                                 (unsigned int)ret);
 180                         r = -ENODEV;
 181                         goto error;
 182                 }
 183                 dev_dbg_f(&udev->dev, "firmware confirm return value %#04x\n",
 184                         (unsigned int)ret);
 185         }
 186
 187         r = 0;
 188 error:
 189         kfree(p);
 190         return r;
 191 }
 192
 193 static u16 get_word(const void *data, u16 offset)
 194 {
 195         const __le16 *p = data;
 196         return le16_to_cpu(p[offset]);
 197 }
 198
 199 static char *get_fw_name(char *buffer, size_t size, u8 device_type,
 200                        const char* postfix)
 201 {
 202         scnprintf(buffer, size, "%s%s",
 203                 device_type == DEVICE_ZD1211B ?
 204                         FW_ZD1211B_PREFIX : FW_ZD1211_PREFIX,
 205                 postfix);
 206         return buffer;
 207 }
 208
 209 static int handle_version_mismatch(struct usb_device *udev, u8 device_type,
 210         const struct firmware *ub_fw)
 211 {
 212         const struct firmware *ur_fw = NULL;
 213         int offset;
 214         int r = 0;
 215         char fw_name[128];
 216
 217         r = request_fw_file(&ur_fw,
 218                 get_fw_name(fw_name, sizeof(fw_name), device_type, "ur"),
 219                 &udev->dev);
 220         if (r)
 221                 goto error;
 222
 223         r = upload_code(udev, ur_fw->data, ur_fw->size, FW_START, REBOOT);
 224         if (r)
 225                 goto error;
 226
 227         offset = (E2P_BOOT_CODE_OFFSET * sizeof(u16));
 228         r = upload_code(udev, ub_fw->data + offset, ub_fw->size - offset,
 229                 E2P_START + E2P_BOOT_CODE_OFFSET, REBOOT);
 230
 231         /* At this point, the vendor driver downloads the whole firmware
 232          * image, hacks around with version IDs, and uploads it again,
 233          * completely overwriting the boot code. We do not do this here as
 234          * it is not required on any tested devices, and it is suspected to
 235          * cause problems. */
 236 error:
 237         release_firmware(ur_fw);
 238         return r;
 239 }
 240
 241 static int upload_firmware(struct usb_device *udev, u8 device_type)
 242 {
 243         int r;
 244         u16 fw_bcdDevice;
 245         u16 bcdDevice;
 246         const struct firmware *ub_fw = NULL;
 247         const struct firmware *uph_fw = NULL;
 248         char fw_name[128];
 249
 250         bcdDevice = get_bcdDevice(udev);
 251
 252         r = request_fw_file(&ub_fw,
 253                 get_fw_name(fw_name, sizeof(fw_name), device_type,  "ub"),
 254                 &udev->dev);
 255         if (r)
 256                 goto error;
 257
 258         fw_bcdDevice = get_word(ub_fw->data, E2P_DATA_OFFSET);
 259
 260         if (fw_bcdDevice != bcdDevice) {
 261                 dev_info(&udev->dev,
 262                         "firmware version %#06x and device bootcode version "
 263                         "%#06x differ\n", fw_bcdDevice, bcdDevice);
 264                 if (bcdDevice <= 0x4313)
 265                         dev_warn(&udev->dev, "device has old bootcode, please "
 266                                 "report success or failure\n");
 267
 268                 r = handle_version_mismatch(udev, device_type, ub_fw);
 269                 if (r)
 270                         goto error;
 271         } else {
 272                 dev_dbg_f(&udev->dev,
 273                         "firmware device id %#06x is equal to the "
 274                         "actual device id\n", fw_bcdDevice);
 275         }
 276
 277
 278         r = request_fw_file(&uph_fw,
 279                 get_fw_name(fw_name, sizeof(fw_name), device_type, "uphr"),
 280                 &udev->dev);
 281         if (r)
 282                 goto error;
 283
 284         r = upload_code(udev, uph_fw->data, uph_fw->size, FW_START, REBOOT);
 285         if (r) {
 286                 dev_err(&udev->dev,
 287                         "Could not upload firmware code uph. Error number %d\n",
 288                         r);
 289         }
 290
 291         /* FALL-THROUGH */
 292 error:
 293         release_firmware(ub_fw);
 294         release_firmware(uph_fw);
 295         return r;
 296 }
 297
 298 #define urb_dev(urb) (&(urb)->dev->dev)
 299
 300 static inline void handle_regs_int(struct urb *urb)
 301 {
 302         struct zd_usb *usb = urb->context;
 303         struct zd_usb_interrupt *intr = &usb->intr;
 304         int len;
 305
 306         ZD_ASSERT(in_interrupt());
 307         spin_lock(&intr->lock);
 308
 309         if (intr->read_regs_enabled) {
 310                 intr->read_regs.length = len = urb->actual_length;
 311
 312                 if (len > sizeof(intr->read_regs.buffer))
 313                         len = sizeof(intr->read_regs.buffer);
 314                 memcpy(intr->read_regs.buffer, urb->transfer_buffer, len);
 315                 intr->read_regs_enabled = 0;
 316                 complete(&intr->read_regs.completion);
 317                 goto out;
 318         }
 319
 320         dev_dbg_f(urb_dev(urb), "regs interrupt ignored\n");
 321 out:
 322         spin_unlock(&intr->lock);
 323 }
 324
 325 static inline void handle_retry_failed_int(struct urb *urb)
 326 {
 327         struct zd_usb *usb = urb->context;
 328         struct zd_mac *mac = zd_usb_to_mac(usb);
 329         struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);
 330
 331         ieee->stats.tx_errors++;
 332         ieee->ieee_stats.tx_retry_limit_exceeded++;
 333         dev_dbg_f(urb_dev(urb), "retry failed interrupt\n");
 334 }
 335
 336
 337 static void int_urb_complete(struct urb *urb)
 338 {
 339         int r;
 340         struct usb_int_header *hdr;
 341
 342         switch (urb->status) {
 343         case 0:
 344                 break;
 345         case -ESHUTDOWN:
 346         case -EINVAL:
 347         case -ENODEV:
 348         case -ENOENT:
 349         case -ECONNRESET:
 350         case -EPIPE:
 351                 goto kfree;
 352         default:
 353                 goto resubmit;
 354         }
 355
 356         if (urb->actual_length < sizeof(hdr)) {
 357                 dev_dbg_f(urb_dev(urb), "error: urb %p to small\n", urb);
 358                 goto resubmit;
 359         }
 360
 361         hdr = urb->transfer_buffer;
 362         if (hdr->type != USB_INT_TYPE) {
 363                 dev_dbg_f(urb_dev(urb), "error: urb %p wrong type\n", urb);
 364                 goto resubmit;
 365         }
 366
 367         switch (hdr->id) {
 368         case USB_INT_ID_REGS:
 369                 handle_regs_int(urb);
 370                 break;
 371         case USB_INT_ID_RETRY_FAILED:
 372                 handle_retry_failed_int(urb);
 373                 break;
 374         default:
 375                 dev_dbg_f(urb_dev(urb), "error: urb %p unknown id %x\n", urb,
 376                         (unsigned int)hdr->id);
 377                 goto resubmit;
 378         }
 379
 380 resubmit:
 381         r = usb_submit_urb(urb, GFP_ATOMIC);
 382         if (r) {
 383                 dev_dbg_f(urb_dev(urb), "resubmit urb %p\n", urb);
 384                 goto kfree;
 385         }
 386         return;
 387 kfree:
 388         kfree(urb->transfer_buffer);
 389 }
 390
 391 static inline int int_urb_interval(struct usb_device *udev)
 392 {
 393         switch (udev->speed) {
 394         case USB_SPEED_HIGH:
 395                 return 4;
 396         case USB_SPEED_LOW:
 397                 return 10;
 398         case USB_SPEED_FULL:
 399         default:
 400                 return 1;
 401         }
 402 }
 403
 404 static inline int usb_int_enabled(struct zd_usb *usb)
 405 {
 406         unsigned long flags;
 407         struct zd_usb_interrupt *intr = &usb->intr;
 408         struct urb *urb;
 409
 410         spin_lock_irqsave(&intr->lock, flags);
 411         urb = intr->urb;
 412         spin_unlock_irqrestore(&intr->lock, flags);
 413         return urb != NULL;
 414 }
 415
 416 int zd_usb_enable_int(struct zd_usb *usb)
 417 {
 418         int r;
 419         struct usb_device *udev;
 420         struct zd_usb_interrupt *intr = &usb->intr;
 421         void *transfer_buffer = NULL;
 422         struct urb *urb;
 423
 424         dev_dbg_f(zd_usb_dev(usb), "\n");
 425
 426         urb = usb_alloc_urb(0, GFP_KERNEL);
 427         if (!urb) {
 428                 r = -ENOMEM;
 429                 goto out;
 430         }
 431
 432         ZD_ASSERT(!irqs_disabled());
 433         spin_lock_irq(&intr->lock);
 434         if (intr->urb) {
 435                 spin_unlock_irq(&intr->lock);
 436                 r = 0;
 437                 goto error_free_urb;
 438         }
 439         intr->urb = urb;
 440         spin_unlock_irq(&intr->lock);
 441
 442         /* TODO: make it a DMA buffer */
 443         r = -ENOMEM;
 444         transfer_buffer = kmalloc(USB_MAX_EP_INT_BUFFER, GFP_KERNEL);
 445         if (!transfer_buffer) {
 446                 dev_dbg_f(zd_usb_dev(usb),
 447                         "couldn't allocate transfer_buffer\n");
 448                 goto error_set_urb_null;
 449         }
 450
 451         udev = zd_usb_to_usbdev(usb);
 452         usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, EP_INT_IN),
 453                          transfer_buffer, USB_MAX_EP_INT_BUFFER,
 454                          int_urb_complete, usb,
 455                          intr->interval);
 456
 457         dev_dbg_f(zd_usb_dev(usb), "submit urb %p\n", intr->urb);
 458         r = usb_submit_urb(urb, GFP_KERNEL);
 459         if (r) {
 460                 dev_dbg_f(zd_usb_dev(usb),
 461                          "Couldn't submit urb. Error number %d\n", r);
 462                 goto error;
 463         }
 464
 465         return 0;
 466 error:
 467         kfree(transfer_buffer);
 468 error_set_urb_null:
 469         spin_lock_irq(&intr->lock);
 470         intr->urb = NULL;
 471         spin_unlock_irq(&intr->lock);
 472 error_free_urb:
 473         usb_free_urb(urb);
 474 out:
 475         return r;
 476 }
 477
 478 void zd_usb_disable_int(struct zd_usb *usb)
 479 {
 480         unsigned long flags;
 481         struct zd_usb_interrupt *intr = &usb->intr;
 482         struct urb *urb;
 483
 484         spin_lock_irqsave(&intr->lock, flags);
 485         urb = intr->urb;
 486         if (!urb) {
 487                 spin_unlock_irqrestore(&intr->lock, flags);
 488                 return;
 489         }
 490         intr->urb = NULL;
 491         spin_unlock_irqrestore(&intr->lock, flags);
 492
 493         usb_kill_urb(urb);
 494         dev_dbg_f(zd_usb_dev(usb), "urb %p killed\n", urb);
 495         usb_free_urb(urb);
 496 }
 497
 498 static void handle_rx_packet(struct zd_usb *usb, const u8 *buffer,
 499                              unsigned int length)
 500 {
 501         int i;
 502         struct zd_mac *mac = zd_usb_to_mac(usb);
 503         const struct rx_length_info *length_info;
 504
 505         if (length < sizeof(struct rx_length_info)) {
 506                 /* It's not a complete packet anyhow. */
 507                 struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);
 508                 ieee->stats.rx_errors++;
 509                 ieee->stats.rx_length_errors++;
 510                 return;
 511         }
 512         length_info = (struct rx_length_info *)
 513                 (buffer + length - sizeof(struct rx_length_info));
 514
 515         /* It might be that three frames are merged into a single URB
 516          * transaction. We have to check for the length info tag.
 517          *
 518          * While testing we discovered that length_info might be unaligned,
 519          * because if USB transactions are merged, the last packet will not
 520          * be padded. Unaligned access might also happen if the length_info
 521          * structure is not present.
 522          */
 523         if (get_unaligned(&length_info->tag) == cpu_to_le16(RX_LENGTH_INFO_TAG))
 524         {
 525                 unsigned int l, k, n;
 526                 for (i = 0, l = 0;; i++) {
 527                         k = le16_to_cpu(get_unaligned(&length_info->length[i]));
 528                         if (k == 0)
 529                                 return;
 530                         n = l+k;
 531                         if (n > length)
 532                                 return;
 533                         zd_mac_rx_irq(mac, buffer+l, k);
 534                         if (i >= 2)
 535                                 return;
 536                         l = (n+3) & ~3;
 537                 }
 538         } else {
 539                 zd_mac_rx_irq(mac, buffer, length);
 540         }
 541 }
 542
 543 static void rx_urb_complete(struct urb *urb)
 544 {
 545         struct zd_usb *usb;
 546         struct zd_usb_rx *rx;
 547         const u8 *buffer;
 548         unsigned int length;
 549
 550         switch (urb->status) {
 551         case 0:
 552                 break;
 553         case -ESHUTDOWN:
 554         case -EINVAL:
 555         case -ENODEV:
 556         case -ENOENT:
 557         case -ECONNRESET:
 558         case -EPIPE:
 559                 return;
 560         default:
 561                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 562                 goto resubmit;
 563         }
 564
 565         buffer = urb->transfer_buffer;
 566         length = urb->actual_length;
 567         usb = urb->context;
 568         rx = &usb->rx;
 569
 570         if (length%rx->usb_packet_size > rx->usb_packet_size-4) {
 571                 /* If there is an old first fragment, we don't care. */
 572                 dev_dbg_f(urb_dev(urb), "*** first fragment ***\n");
 573                 ZD_ASSERT(length <= ARRAY_SIZE(rx->fragment));
 574                 spin_lock(&rx->lock);
 575                 memcpy(rx->fragment, buffer, length);
 576                 rx->fragment_length = length;
 577                 spin_unlock(&rx->lock);
 578                 goto resubmit;
 579         }
 580
 581         spin_lock(&rx->lock);
 582         if (rx->fragment_length > 0) {
 583                 /* We are on a second fragment, we believe */
 584                 ZD_ASSERT(length + rx->fragment_length <=
 585                           ARRAY_SIZE(rx->fragment));
 586                 dev_dbg_f(urb_dev(urb), "*** second fragment ***\n");
 587                 memcpy(rx->fragment+rx->fragment_length, buffer, length);
 588                 handle_rx_packet(usb, rx->fragment,
 589                                  rx->fragment_length + length);
 590                 rx->fragment_length = 0;
 591                 spin_unlock(&rx->lock);
 592         } else {
 593                 spin_unlock(&rx->lock);
 594                 handle_rx_packet(usb, buffer, length);
 595         }
 596
 597 resubmit:
 598         usb_submit_urb(urb, GFP_ATOMIC);
 599 }
 600
 601 static struct urb *alloc_urb(struct zd_usb *usb)
 602 {
 603         struct usb_device *udev = zd_usb_to_usbdev(usb);
 604         struct urb *urb;
 605         void *buffer;
 606
 607         urb = usb_alloc_urb(0, GFP_KERNEL);
 608         if (!urb)
 609                 return NULL;
 610         buffer = usb_buffer_alloc(udev, USB_MAX_RX_SIZE, GFP_KERNEL,
 611                                   &urb->transfer_dma);
 612         if (!buffer) {
 613                 usb_free_urb(urb);
 614                 return NULL;
 615         }
 616
 617         usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_DATA_IN),
 618                           buffer, USB_MAX_RX_SIZE,
 619                           rx_urb_complete, usb);
 620         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 621
 622         return urb;
 623 }
 624
 625 static void free_urb(struct urb *urb)
 626 {
 627         if (!urb)
 628                 return;
 629         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 630                         urb->transfer_buffer, urb->transfer_dma);
 631         usb_free_urb(urb);
 632 }
 633
 634 int zd_usb_enable_rx(struct zd_usb *usb)
 635 {
 636         int i, r;
 637         struct zd_usb_rx *rx = &usb->rx;
 638         struct urb **urbs;
 639
 640         dev_dbg_f(zd_usb_dev(usb), "\n");
 641
 642         r = -ENOMEM;
 643         urbs = kcalloc(URBS_COUNT, sizeof(struct urb *), GFP_KERNEL);
 644         if (!urbs)
 645                 goto error;
 646         for (i = 0; i < URBS_COUNT; i++) {
 647                 urbs[i] = alloc_urb(usb);
 648                 if (!urbs[i])
 649                         goto error;
 650         }
 651
 652         ZD_ASSERT(!irqs_disabled());
 653         spin_lock_irq(&rx->lock);
 654         if (rx->urbs) {
 655                 spin_unlock_irq(&rx->lock);
 656                 r = 0;
 657                 goto error;
 658         }
 659         rx->urbs = urbs;
 660         rx->urbs_count = URBS_COUNT;
 661         spin_unlock_irq(&rx->lock);
 662
 663         for (i = 0; i < URBS_COUNT; i++) {
 664                 r = usb_submit_urb(urbs[i], GFP_KERNEL);
 665                 if (r)
 666                         goto error_submit;
 667         }
 668
 669         return 0;
 670 error_submit:
 671         for (i = 0; i < URBS_COUNT; i++) {
 672                 usb_kill_urb(urbs[i]);
 673         }
 674         spin_lock_irq(&rx->lock);
 675         rx->urbs = NULL;
 676         rx->urbs_count = 0;
 677         spin_unlock_irq(&rx->lock);
 678 error:
 679         if (urbs) {
 680                 for (i = 0; i < URBS_COUNT; i++)
 681                         free_urb(urbs[i]);
 682         }
 683         return r;
 684 }
 685
 686 void zd_usb_disable_rx(struct zd_usb *usb)
 687 {
 688         int i;
 689         unsigned long flags;
 690         struct urb **urbs;
 691         unsigned int count;
 692         struct zd_usb_rx *rx = &usb->rx;
 693
 694         spin_lock_irqsave(&rx->lock, flags);
 695         urbs = rx->urbs;
 696         count = rx->urbs_count;
 697         spin_unlock_irqrestore(&rx->lock, flags);
 698         if (!urbs)
 699                 return;
 700
 701         for (i = 0; i < count; i++) {
 702                 usb_kill_urb(urbs[i]);
 703                 free_urb(urbs[i]);
 704         }
 705         kfree(urbs);
 706
 707         spin_lock_irqsave(&rx->lock, flags);
 708         rx->urbs = NULL;
 709         rx->urbs_count = 0;
 710         spin_unlock_irqrestore(&rx->lock, flags);
 711 }
 712
 713 static void tx_urb_complete(struct urb *urb)
 714 {
 715         int r;
 716
 717         switch (urb->status) {
 718         case 0:
 719                 break;
 720         case -ESHUTDOWN:
 721         case -EINVAL:
 722         case -ENODEV:
 723         case -ENOENT:
 724         case -ECONNRESET:
 725         case -EPIPE:
 726                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 727                 break;
 728         default:
 729                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 730                 goto resubmit;
 731         }
 732 free_urb:
 733         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 734                         urb->transfer_buffer, urb->transfer_dma);
 735         usb_free_urb(urb);
 736         return;
 737 resubmit:
 738         r = usb_submit_urb(urb, GFP_ATOMIC);
 739         if (r) {
 740                 dev_dbg_f(urb_dev(urb), "error resubmit urb %p %d\n", urb, r);
 741                 goto free_urb;
 742         }
 743 }
 744
 745 /* Puts the frame on the USB endpoint. It doesn't wait for
 746  * completion. The frame must contain the control set.
 747  */
 748 int zd_usb_tx(struct zd_usb *usb, const u8 *frame, unsigned int length)
 749 {
 750         int r;
 751         struct usb_device *udev = zd_usb_to_usbdev(usb);
 752         struct urb *urb;
 753         void *buffer;
 754
 755         urb = usb_alloc_urb(0, GFP_ATOMIC);
 756         if (!urb) {
 757                 r = -ENOMEM;
 758                 goto out;
 759         }
 760
 761         buffer = usb_buffer_alloc(zd_usb_to_usbdev(usb), length, GFP_ATOMIC,
 762                                   &urb->transfer_dma);
 763         if (!buffer) {
 764                 r = -ENOMEM;
 765                 goto error_free_urb;
 766         }
 767         memcpy(buffer, frame, length);
 768
 769         usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, EP_DATA_OUT),
 770                           buffer, length, tx_urb_complete, NULL);
 771         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 772
 773         r = usb_submit_urb(urb, GFP_ATOMIC);
 774         if (r)
 775                 goto error;
 776         return 0;
 777 error:
 778         usb_buffer_free(zd_usb_to_usbdev(usb), length, buffer,
 779                         urb->transfer_dma);
 780 error_free_urb:
 781         usb_free_urb(urb);
 782 out:
 783         return r;
 784 }
 785
 786 static inline void init_usb_interrupt(struct zd_usb *usb)
 787 {
 788         struct zd_usb_interrupt *intr = &usb->intr;
 789
 790         spin_lock_init(&intr->lock);
 791         intr->interval = int_urb_interval(zd_usb_to_usbdev(usb));
 792         init_completion(&intr->read_regs.completion);
 793         intr->read_regs.cr_int_addr = cpu_to_le16((u16)CR_INTERRUPT);
 794 }
 795
 796 static inline void init_usb_rx(struct zd_usb *usb)
 797 {
 798         struct zd_usb_rx *rx = &usb->rx;
 799         spin_lock_init(&rx->lock);
 800         if (interface_to_usbdev(usb->intf)->speed == USB_SPEED_HIGH) {
 801                 rx->usb_packet_size = 512;
 802         } else {
 803                 rx->usb_packet_size = 64;
 804         }
 805         ZD_ASSERT(rx->fragment_length == 0);
 806 }
 807
 808 static inline void init_usb_tx(struct zd_usb *usb)
 809 {
 810         /* FIXME: at this point we will allocate a fixed number of urb's for
 811          * use in a cyclic scheme */
 812 }
 813
 814 void zd_usb_init(struct zd_usb *usb, struct net_device *netdev,
 815                  struct usb_interface *intf)
 816 {
 817         memset(usb, 0, sizeof(*usb));
 818         usb->intf = usb_get_intf(intf);
 819         usb_set_intfdata(usb->intf, netdev);
 820         init_usb_interrupt(usb);
 821         init_usb_tx(usb);
 822         init_usb_rx(usb);
 823 }
 824
 825 void zd_usb_clear(struct zd_usb *usb)
 826 {
 827         usb_set_intfdata(usb->intf, NULL);
 828         usb_put_intf(usb->intf);
 829         ZD_MEMCLEAR(usb, sizeof(*usb));
 830         /* FIXME: usb_interrupt, usb_tx, usb_rx? */
 831 }
 832
 833 static const char *speed(enum usb_device_speed speed)
 834 {
 835         switch (speed) {
 836         case USB_SPEED_LOW:
 837                 return "low";
 838         case USB_SPEED_FULL:
 839                 return "full";
 840         case USB_SPEED_HIGH:
 841                 return "high";
 842         default:
 843                 return "unknown speed";
 844         }
 845 }
 846
 847 static int scnprint_id(struct usb_device *udev, char *buffer, size_t size)
 848 {
 849         return scnprintf(buffer, size, "%04hx:%04hx v%04hx %s",
 850                 le16_to_cpu(udev->descriptor.idVendor),
 851                 le16_to_cpu(udev->descriptor.idProduct),
 852                 get_bcdDevice(udev),
 853                 speed(udev->speed));
 854 }
 855
 856 int zd_usb_scnprint_id(struct zd_usb *usb, char *buffer, size_t size)
 857 {
 858         struct usb_device *udev = interface_to_usbdev(usb->intf);
 859         return scnprint_id(udev, buffer, size);
 860 }
 861
 862 #ifdef DEBUG
 863 static void print_id(struct usb_device *udev)
 864 {
 865         char buffer[40];
 866
 867         scnprint_id(udev, buffer, sizeof(buffer));
 868         buffer[sizeof(buffer)-1] = 0;
 869         dev_dbg_f(&udev->dev, "%s\n", buffer);
 870 }
 871 #else
 872 #define print_id(udev) do { } while (0)
 873 #endif
 874
 875 static int eject_installer(struct usb_interface *intf)
 876 {
 877         struct usb_device *udev = interface_to_usbdev(intf);
 878         struct usb_host_interface *iface_desc = &intf->altsetting[0];
 879         struct usb_endpoint_descriptor *endpoint;
 880         unsigned char *cmd;
 881         u8 bulk_out_ep;
 882         int r;
 883
 884         /* Find bulk out endpoint */
 885         endpoint = &iface_desc->endpoint[1].desc;
 886         if ((endpoint->bEndpointAddress & USB_TYPE_MASK) == USB_DIR_OUT &&
 887             (endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
 888             USB_ENDPOINT_XFER_BULK) {
 889                 bulk_out_ep = endpoint->bEndpointAddress;
 890         } else {
 891                 dev_err(&udev->dev,
 892                         "zd1211rw: Could not find bulk out endpoint\n");
 893                 return -ENODEV;
 894         }
 895
 896         cmd = kzalloc(31, GFP_KERNEL);
 897         if (cmd == NULL)
 898                 return -ENODEV;
 899
 900         /* USB bulk command block */
 901         cmd[0] = 0x55;  /* bulk command signature */
 902         cmd[1] = 0x53;  /* bulk command signature */
 903         cmd[2] = 0x42;  /* bulk command signature */
 904         cmd[3] = 0x43;  /* bulk command signature */
 905         cmd[14] = 6;    /* command length */
 906
 907         cmd[15] = 0x1b; /* SCSI command: START STOP UNIT */
 908         cmd[19] = 0x2;  /* eject disc */
 909
 910         dev_info(&udev->dev, "Ejecting virtual installer media...\n");
 911         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, bulk_out_ep),
 912                 cmd, 31, NULL, 2000);
 913         kfree(cmd);
 914         if (r)
 915                 return r;
 916
 917         /* At this point, the device disconnects and reconnects with the real
 918          * ID numbers. */
 919
 920         usb_set_intfdata(intf, NULL);
 921         return 0;
 922 }
 923
 924 static int probe(struct usb_interface *intf, const struct usb_device_id *id)
 925 {
 926         int r;
 927         struct usb_device *udev = interface_to_usbdev(intf);
 928         struct net_device *netdev = NULL;
 929
 930         print_id(udev);
 931
 932         if (id->driver_info & DEVICE_INSTALLER)
 933                 return eject_installer(intf);
 934
 935         switch (udev->speed) {
 936         case USB_SPEED_LOW:
 937         case USB_SPEED_FULL:
 938         case USB_SPEED_HIGH:
 939                 break;
 940         default:
 941                 dev_dbg_f(&intf->dev, "Unknown USB speed\n");
 942                 r = -ENODEV;
 943                 goto error;
 944         }
 945
 946         usb_reset_device(interface_to_usbdev(intf));
 947
 948         netdev = zd_netdev_alloc(intf);
 949         if (netdev == NULL) {
 950                 r = -ENOMEM;
 951                 goto error;
 952         }
 953
 954         r = upload_firmware(udev, id->driver_info);
 955         if (r) {
 956                 dev_err(&intf->dev,
 957                        "couldn't load firmware. Error number %d\n", r);
 958                 goto error;
 959         }
 960
 961         r = usb_reset_configuration(udev);
 962         if (r) {
 963                 dev_dbg_f(&intf->dev,
 964                         "couldn't reset configuration. Error number %d\n", r);
 965                 goto error;
 966         }
 967
 968         /* At this point the interrupt endpoint is not generally enabled. We
 969          * save the USB bandwidth until the network device is opened. But
 970          * notify that the initialization of the MAC will require the
 971          * interrupts to be temporary enabled.
 972          */
 973         r = zd_mac_init_hw(zd_netdev_mac(netdev), id->driver_info);
 974         if (r) {
 975                 dev_dbg_f(&intf->dev,
 976                          "couldn't initialize mac. Error number %d\n", r);
 977                 goto error;
 978         }
 979
 980         r = register_netdev(netdev);
 981         if (r) {
 982                 dev_dbg_f(&intf->dev,
 983                          "couldn't register netdev. Error number %d\n", r);
 984                 goto error;
 985         }
 986
 987         dev_dbg_f(&intf->dev, "successful\n");
 988         dev_info(&intf->dev,"%s\n", netdev->name);
 989         return 0;
 990 error:
 991         usb_reset_device(interface_to_usbdev(intf));
 992         zd_netdev_free(netdev);
 993         return r;
 994 }
 995
 996 static void disconnect(struct usb_interface *intf)
 997 {
 998         struct net_device *netdev = zd_intf_to_netdev(intf);
 999         struct zd_mac *mac = zd_netdev_mac(netdev);
1000         struct zd_usb *usb = &mac->chip.usb;
1001
1002         /* Either something really bad happened, or we're just dealing with
1003          * a DEVICE_INSTALLER. */
1004         if (netdev == NULL)
1005                 return;
1006
1007         dev_dbg_f(zd_usb_dev(usb), "\n");
1008
1009         zd_netdev_disconnect(netdev);
1010
1011         /* Just in case something has gone wrong! */
1012         zd_usb_disable_rx(usb);
1013         zd_usb_disable_int(usb);
1014
1015         /* If the disconnect has been caused by a removal of the
1016          * driver module, the reset allows reloading of the driver. If the
1017          * reset will not be executed here, the upload of the firmware in the
1018          * probe function caused by the reloading of the driver will fail.
1019          */
1020         usb_reset_device(interface_to_usbdev(intf));
1021
1022         zd_netdev_free(netdev);
1023         dev_dbg(&intf->dev, "disconnected\n");
1024 }
1025
1026 static struct usb_driver driver = {
1027         .name           = "zd1211rw",
1028         .id_table       = usb_ids,
1029         .probe          = probe,
1030         .disconnect     = disconnect,
1031 };
1032
1033 struct workqueue_struct *zd_workqueue;
1034
1035 static int __init usb_init(void)
1036 {
1037         int r;
1038
1039         pr_debug("%s usb_init()\n", driver.name);
1040
1041         zd_workqueue = create_singlethread_workqueue(driver.name);
1042         if (zd_workqueue == NULL) {
1043                 printk(KERN_ERR "%s couldn't create workqueue\n", driver.name);
1044                 return -ENOMEM;
1045         }
1046
1047         r = usb_register(&driver);
1048         if (r) {
1049                 destroy_workqueue(zd_workqueue);
1050                 printk(KERN_ERR "%s usb_register() failed. Error number %d\n",
1051                        driver.name, r);
1052                 return r;
1053         }
1054
1055         pr_debug("%s initialized\n", driver.name);
1056         return 0;
1057 }
1058
1059 static void __exit usb_exit(void)
1060 {
1061         pr_debug("%s usb_exit()\n", driver.name);
1062         usb_deregister(&driver);
1063         destroy_workqueue(zd_workqueue);
1064 }
1065
1066 module_init(usb_init);
1067 module_exit(usb_exit);
1068
1069 static int usb_int_regs_length(unsigned int count)
1070 {
1071         return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data);
1072 }
1073
1074 static void prepare_read_regs_int(struct zd_usb *usb)
1075 {
1076         struct zd_usb_interrupt *intr = &usb->intr;
1077
1078         spin_lock_irq(&intr->lock);
1079         intr->read_regs_enabled = 1;
1080         INIT_COMPLETION(intr->read_regs.completion);
1081         spin_unlock_irq(&intr->lock);
1082 }
1083
1084 static void disable_read_regs_int(struct zd_usb *usb)
1085 {
1086         struct zd_usb_interrupt *intr = &usb->intr;
1087
1088         spin_lock_irq(&intr->lock);
1089         intr->read_regs_enabled = 0;
1090         spin_unlock_irq(&intr->lock);
1091 }
1092
1093 static int get_results(struct zd_usb *usb, u16 *values,
1094                        struct usb_req_read_regs *req, unsigned int count)
1095 {
1096         int r;
1097         int i;
1098         struct zd_usb_interrupt *intr = &usb->intr;
1099         struct read_regs_int *rr = &intr->read_regs;
1100         struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
1101
1102         spin_lock_irq(&intr->lock);
1103
1104         r = -EIO;
1105         /* The created block size seems to be larger than expected.
1106          * However results appear to be correct.
1107          */
1108         if (rr->length < usb_int_regs_length(count)) {
1109                 dev_dbg_f(zd_usb_dev(usb),
1110                          "error: actual length %d less than expected %d\n",
1111                          rr->length, usb_int_regs_length(count));
1112                 goto error_unlock;
1113         }
1114         if (rr->length > sizeof(rr->buffer)) {
1115                 dev_dbg_f(zd_usb_dev(usb),
1116                          "error: actual length %d exceeds buffer size %zu\n",
1117                          rr->length, sizeof(rr->buffer));
1118                 goto error_unlock;
1119         }
1120
1121         for (i = 0; i < count; i++) {
1122                 struct reg_data *rd = &regs->regs[i];
1123                 if (rd->addr != req->addr[i]) {
1124                         dev_dbg_f(zd_usb_dev(usb),
1125                                  "rd[%d] addr %#06hx expected %#06hx\n", i,
1126                                  le16_to_cpu(rd->addr),
1127                                  le16_to_cpu(req->addr[i]));
1128                         goto error_unlock;
1129                 }
1130                 values[i] = le16_to_cpu(rd->value);
1131         }
1132
1133         r = 0;
1134 error_unlock:
1135         spin_unlock_irq(&intr->lock);
1136         return r;
1137 }
1138
1139 int zd_usb_ioread16v(struct zd_usb *usb, u16 *values,
1140                      const zd_addr_t *addresses, unsigned int count)
1141 {
1142         int r;
1143         int i, req_len, actual_req_len;
1144         struct usb_device *udev;
1145         struct usb_req_read_regs *req = NULL;
1146         unsigned long timeout;
1147
1148         if (count < 1) {
1149                 dev_dbg_f(zd_usb_dev(usb), "error: count is zero\n");
1150                 return -EINVAL;
1151         }
1152         if (count > USB_MAX_IOREAD16_COUNT) {
1153                 dev_dbg_f(zd_usb_dev(usb),
1154                          "error: count %u exceeds possible max %u\n",
1155                          count, USB_MAX_IOREAD16_COUNT);
1156                 return -EINVAL;
1157         }
1158         if (in_atomic()) {
1159                 dev_dbg_f(zd_usb_dev(usb),
1160                          "error: io in atomic context not supported\n");
1161                 return -EWOULDBLOCK;
1162         }
1163         if (!usb_int_enabled(usb)) {
1164                  dev_dbg_f(zd_usb_dev(usb),
1165                           "error: usb interrupt not enabled\n");
1166                 return -EWOULDBLOCK;
1167         }
1168
1169         req_len = sizeof(struct usb_req_read_regs) + count * sizeof(__le16);
1170         req = kmalloc(req_len, GFP_KERNEL);
1171         if (!req)
1172                 return -ENOMEM;
1173         req->id = cpu_to_le16(USB_REQ_READ_REGS);
1174         for (i = 0; i < count; i++)
1175                 req->addr[i] = cpu_to_le16((u16)addresses[i]);
1176
1177         udev = zd_usb_to_usbdev(usb);
1178         prepare_read_regs_int(usb);
1179         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1180                          req, req_len, &actual_req_len, 1000 /* ms */);
1181         if (r) {
1182                 dev_dbg_f(zd_usb_dev(usb),
1183                         "error in usb_bulk_msg(). Error number %d\n", r);
1184                 goto error;
1185         }
1186         if (req_len != actual_req_len) {
1187                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()\n"
1188                         " req_len %d != actual_req_len %d\n",
1189                         req_len, actual_req_len);
1190                 r = -EIO;
1191                 goto error;
1192         }
1193
1194         timeout = wait_for_completion_timeout(&usb->intr.read_regs.completion,
1195                                               msecs_to_jiffies(1000));
1196         if (!timeout) {
1197                 disable_read_regs_int(usb);
1198                 dev_dbg_f(zd_usb_dev(usb), "read timed out\n");
1199                 r = -ETIMEDOUT;
1200                 goto error;
1201         }
1202
1203         r = get_results(usb, values, req, count);
1204 error:
1205         kfree(req);
1206         return r;
1207 }
1208
1209 int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
1210                       unsigned int count)
1211 {
1212         int r;
1213         struct usb_device *udev;
1214         struct usb_req_write_regs *req = NULL;
1215         int i, req_len, actual_req_len;
1216
1217         if (count == 0)
1218                 return 0;
1219         if (count > USB_MAX_IOWRITE16_COUNT) {
1220                 dev_dbg_f(zd_usb_dev(usb),
1221                         "error: count %u exceeds possible max %u\n",
1222                         count, USB_MAX_IOWRITE16_COUNT);
1223                 return -EINVAL;
1224         }
1225         if (in_atomic()) {
1226                 dev_dbg_f(zd_usb_dev(usb),
1227                         "error: io in atomic context not supported\n");
1228                 return -EWOULDBLOCK;
1229         }
1230
1231         req_len = sizeof(struct usb_req_write_regs) +
1232                   count * sizeof(struct reg_data);
1233         req = kmalloc(req_len, GFP_KERNEL);
1234         if (!req)
1235                 return -ENOMEM;
1236
1237         req->id = cpu_to_le16(USB_REQ_WRITE_REGS);
1238         for (i = 0; i < count; i++) {
1239                 struct reg_data *rw  = &req->reg_writes[i];
1240                 rw->addr = cpu_to_le16((u16)ioreqs[i].addr);
1241                 rw->value = cpu_to_le16(ioreqs[i].value);
1242         }
1243
1244         udev = zd_usb_to_usbdev(usb);
1245         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1246                          req, req_len, &actual_req_len, 1000 /* ms */);
1247         if (r) {
1248                 dev_dbg_f(zd_usb_dev(usb),
1249                         "error in usb_bulk_msg(). Error number %d\n", r);
1250                 goto error;
1251         }
1252         if (req_len != actual_req_len) {
1253                 dev_dbg_f(zd_usb_dev(usb),
1254                         "error in usb_bulk_msg()"
1255                         " req_len %d != actual_req_len %d\n",
1256                         req_len, actual_req_len);
1257                 r = -EIO;
1258                 goto error;
1259         }
1260
1261         /* FALL-THROUGH with r == 0 */
1262 error:
1263         kfree(req);
1264         return r;
1265 }
1266
1267 int zd_usb_rfwrite(struct zd_usb *usb, u32 value, u8 bits)
1268 {
1269         int r;
1270         struct usb_device *udev;
1271         struct usb_req_rfwrite *req = NULL;
1272         int i, req_len, actual_req_len;
1273         u16 bit_value_template;
1274
1275         if (in_atomic()) {
1276                 dev_dbg_f(zd_usb_dev(usb),
1277                         "error: io in atomic context not supported\n");
1278                 return -EWOULDBLOCK;
1279         }
1280         if (bits < USB_MIN_RFWRITE_BIT_COUNT) {
1281                 dev_dbg_f(zd_usb_dev(usb),
1282                         "error: bits %d are smaller than"
1283                         " USB_MIN_RFWRITE_BIT_COUNT %d\n",
1284                         bits, USB_MIN_RFWRITE_BIT_COUNT);
1285                 return -EINVAL;
1286         }
1287         if (bits > USB_MAX_RFWRITE_BIT_COUNT) {
1288                 dev_dbg_f(zd_usb_dev(usb),
1289                         "error: bits %d exceed USB_MAX_RFWRITE_BIT_COUNT %d\n",
1290                         bits, USB_MAX_RFWRITE_BIT_COUNT);
1291                 return -EINVAL;
1292         }
1293 #ifdef DEBUG
1294         if (value & (~0UL << bits)) {
1295                 dev_dbg_f(zd_usb_dev(usb),
1296                         "error: value %#09x has bits >= %d set\n",
1297                         value, bits);
1298                 return -EINVAL;
1299         }
1300 #endif /* DEBUG */
1301
1302         dev_dbg_f(zd_usb_dev(usb), "value %#09x bits %d\n", value, bits);
1303
1304         r = zd_usb_ioread16(usb, &bit_value_template, CR203);
1305         if (r) {
1306                 dev_dbg_f(zd_usb_dev(usb),
1307                         "error %d: Couldn't read CR203\n", r);
1308                 goto out;
1309         }
1310         bit_value_template &= ~(RF_IF_LE|RF_CLK|RF_DATA);
1311
1312         req_len = sizeof(struct usb_req_rfwrite) + bits * sizeof(__le16);
1313         req = kmalloc(req_len, GFP_KERNEL);
1314         if (!req)
1315                 return -ENOMEM;
1316
1317         req->id = cpu_to_le16(USB_REQ_WRITE_RF);
1318         /* 1: 3683a, but not used in ZYDAS driver */
1319         req->value = cpu_to_le16(2);
1320         req->bits = cpu_to_le16(bits);
1321
1322         for (i = 0; i < bits; i++) {
1323                 u16 bv = bit_value_template;
1324                 if (value & (1 << (bits-1-i)))
1325                         bv |= RF_DATA;
1326                 req->bit_values[i] = cpu_to_le16(bv);
1327         }
1328
1329         udev = zd_usb_to_usbdev(usb);
1330         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1331                          req, req_len, &actual_req_len, 1000 /* ms */);
1332         if (r) {
1333                 dev_dbg_f(zd_usb_dev(usb),
1334                         "error in usb_bulk_msg(). Error number %d\n", r);
1335                 goto out;
1336         }
1337         if (req_len != actual_req_len) {
1338                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()"
1339                         " req_len %d != actual_req_len %d\n",
1340                         req_len, actual_req_len);
1341                 r = -EIO;
1342                 goto out;
1343         }
1344
1345         /* FALL-THROUGH with r == 0 */
1346 out:
1347         kfree(req);
1348         return r;
1349 }