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