git.oblomov.eu Git - linux-2.6/blob - 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(0x0586, 0x3413), .driver_info = DEVICE_ZD1211B },
  72         { USB_DEVICE(0x0053, 0x5301), .driver_info = DEVICE_ZD1211B },
  73         /* "Driverless" devices that need ejecting */
  74         { USB_DEVICE(0x0ace, 0x2011), .driver_info = DEVICE_INSTALLER },
  75         { USB_DEVICE(0x0ace, 0x20ff), .driver_info = DEVICE_INSTALLER },
  76         {}
  77 };
  78
  79 MODULE_LICENSE("GPL");
  80 MODULE_DESCRIPTION("USB driver for devices with the ZD1211 chip.");
  81 MODULE_AUTHOR("Ulrich Kunitz");
  82 MODULE_AUTHOR("Daniel Drake");
  83 MODULE_VERSION("1.0");
  84 MODULE_DEVICE_TABLE(usb, usb_ids);
  85
  86 #define FW_ZD1211_PREFIX        "zd1211/zd1211_"
  87 #define FW_ZD1211B_PREFIX       "zd1211/zd1211b_"
  88
  89 /* USB device initialization */
  90
  91 static int request_fw_file(
  92         const struct firmware **fw, const char *name, struct device *device)
  93 {
  94         int r;
  95
  96         dev_dbg_f(device, "fw name %s\n", name);
  97
  98         r = request_firmware(fw, name, device);
  99         if (r)
 100                 dev_err(device,
 101                        "Could not load firmware file %s. Error number %d\n",
 102                        name, r);
 103         return r;
 104 }
 105
 106 static inline u16 get_bcdDevice(const struct usb_device *udev)
 107 {
 108         return le16_to_cpu(udev->descriptor.bcdDevice);
 109 }
 110
 111 enum upload_code_flags {
 112         REBOOT = 1,
 113 };
 114
 115 /* Ensures that MAX_TRANSFER_SIZE is even. */
 116 #define MAX_TRANSFER_SIZE (USB_MAX_TRANSFER_SIZE & ~1)
 117
 118 static int upload_code(struct usb_device *udev,
 119         const u8 *data, size_t size, u16 code_offset, int flags)
 120 {
 121         u8 *p;
 122         int r;
 123
 124         /* USB request blocks need "kmalloced" buffers.
 125          */
 126         p = kmalloc(MAX_TRANSFER_SIZE, GFP_KERNEL);
 127         if (!p) {
 128                 dev_err(&udev->dev, "out of memory\n");
 129                 r = -ENOMEM;
 130                 goto error;
 131         }
 132
 133         size &= ~1;
 134         while (size > 0) {
 135                 size_t transfer_size = size <= MAX_TRANSFER_SIZE ?
 136                         size : MAX_TRANSFER_SIZE;
 137
 138                 dev_dbg_f(&udev->dev, "transfer size %zu\n", transfer_size);
 139
 140                 memcpy(p, data, transfer_size);
 141                 r = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 142                         USB_REQ_FIRMWARE_DOWNLOAD,
 143                         USB_DIR_OUT | USB_TYPE_VENDOR,
 144                         code_offset, 0, p, transfer_size, 1000 /* ms */);
 145                 if (r < 0) {
 146                         dev_err(&udev->dev,
 147                                "USB control request for firmware upload"
 148                                " failed. Error number %d\n", r);
 149                         goto error;
 150                 }
 151                 transfer_size = r & ~1;
 152
 153                 size -= transfer_size;
 154                 data += transfer_size;
 155                 code_offset += transfer_size/sizeof(u16);
 156         }
 157
 158         if (flags & REBOOT) {
 159                 u8 ret;
 160
 161                 r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
 162                         USB_REQ_FIRMWARE_CONFIRM,
 163                         USB_DIR_IN | USB_TYPE_VENDOR,
 164                         0, 0, &ret, sizeof(ret), 5000 /* ms */);
 165                 if (r != sizeof(ret)) {
 166                         dev_err(&udev->dev,
 167                                 "control request firmeware confirmation failed."
 168                                 " Return value %d\n", r);
 169                         if (r >= 0)
 170                                 r = -ENODEV;
 171                         goto error;
 172                 }
 173                 if (ret & 0x80) {
 174                         dev_err(&udev->dev,
 175                                 "Internal error while downloading."
 176                                 " Firmware confirm return value %#04x\n",
 177                                 (unsigned int)ret);
 178                         r = -ENODEV;
 179                         goto error;
 180                 }
 181                 dev_dbg_f(&udev->dev, "firmware confirm return value %#04x\n",
 182                         (unsigned int)ret);
 183         }
 184
 185         r = 0;
 186 error:
 187         kfree(p);
 188         return r;
 189 }
 190
 191 static u16 get_word(const void *data, u16 offset)
 192 {
 193         const __le16 *p = data;
 194         return le16_to_cpu(p[offset]);
 195 }
 196
 197 static char *get_fw_name(char *buffer, size_t size, u8 device_type,
 198                        const char* postfix)
 199 {
 200         scnprintf(buffer, size, "%s%s",
 201                 device_type == DEVICE_ZD1211B ?
 202                         FW_ZD1211B_PREFIX : FW_ZD1211_PREFIX,
 203                 postfix);
 204         return buffer;
 205 }
 206
 207 static int handle_version_mismatch(struct usb_device *udev, u8 device_type,
 208         const struct firmware *ub_fw)
 209 {
 210         const struct firmware *ur_fw = NULL;
 211         int offset;
 212         int r = 0;
 213         char fw_name[128];
 214
 215         r = request_fw_file(&ur_fw,
 216                 get_fw_name(fw_name, sizeof(fw_name), device_type, "ur"),
 217                 &udev->dev);
 218         if (r)
 219                 goto error;
 220
 221         r = upload_code(udev, ur_fw->data, ur_fw->size, FW_START, REBOOT);
 222         if (r)
 223                 goto error;
 224
 225         offset = (E2P_BOOT_CODE_OFFSET * sizeof(u16));
 226         r = upload_code(udev, ub_fw->data + offset, ub_fw->size - offset,
 227                 E2P_START + E2P_BOOT_CODE_OFFSET, REBOOT);
 228
 229         /* At this point, the vendor driver downloads the whole firmware
 230          * image, hacks around with version IDs, and uploads it again,
 231          * completely overwriting the boot code. We do not do this here as
 232          * it is not required on any tested devices, and it is suspected to
 233          * cause problems. */
 234 error:
 235         release_firmware(ur_fw);
 236         return r;
 237 }
 238
 239 static int upload_firmware(struct usb_device *udev, u8 device_type)
 240 {
 241         int r;
 242         u16 fw_bcdDevice;
 243         u16 bcdDevice;
 244         const struct firmware *ub_fw = NULL;
 245         const struct firmware *uph_fw = NULL;
 246         char fw_name[128];
 247
 248         bcdDevice = get_bcdDevice(udev);
 249
 250         r = request_fw_file(&ub_fw,
 251                 get_fw_name(fw_name, sizeof(fw_name), device_type,  "ub"),
 252                 &udev->dev);
 253         if (r)
 254                 goto error;
 255
 256         fw_bcdDevice = get_word(ub_fw->data, E2P_DATA_OFFSET);
 257
 258         if (fw_bcdDevice != bcdDevice) {
 259                 dev_info(&udev->dev,
 260                         "firmware version %#06x and device bootcode version "
 261                         "%#06x differ\n", fw_bcdDevice, bcdDevice);
 262                 if (bcdDevice <= 0x4313)
 263                         dev_warn(&udev->dev, "device has old bootcode, please "
 264                                 "report success or failure\n");
 265
 266                 r = handle_version_mismatch(udev, device_type, ub_fw);
 267                 if (r)
 268                         goto error;
 269         } else {
 270                 dev_dbg_f(&udev->dev,
 271                         "firmware device id %#06x is equal to the "
 272                         "actual device id\n", fw_bcdDevice);
 273         }
 274
 275
 276         r = request_fw_file(&uph_fw,
 277                 get_fw_name(fw_name, sizeof(fw_name), device_type, "uphr"),
 278                 &udev->dev);
 279         if (r)
 280                 goto error;
 281
 282         r = upload_code(udev, uph_fw->data, uph_fw->size, FW_START, REBOOT);
 283         if (r) {
 284                 dev_err(&udev->dev,
 285                         "Could not upload firmware code uph. Error number %d\n",
 286                         r);
 287         }
 288
 289         /* FALL-THROUGH */
 290 error:
 291         release_firmware(ub_fw);
 292         release_firmware(uph_fw);
 293         return r;
 294 }
 295
 296 #define urb_dev(urb) (&(urb)->dev->dev)
 297
 298 static inline void handle_regs_int(struct urb *urb)
 299 {
 300         struct zd_usb *usb = urb->context;
 301         struct zd_usb_interrupt *intr = &usb->intr;
 302         int len;
 303
 304         ZD_ASSERT(in_interrupt());
 305         spin_lock(&intr->lock);
 306
 307         if (intr->read_regs_enabled) {
 308                 intr->read_regs.length = len = urb->actual_length;
 309
 310                 if (len > sizeof(intr->read_regs.buffer))
 311                         len = sizeof(intr->read_regs.buffer);
 312                 memcpy(intr->read_regs.buffer, urb->transfer_buffer, len);
 313                 intr->read_regs_enabled = 0;
 314                 complete(&intr->read_regs.completion);
 315                 goto out;
 316         }
 317
 318         dev_dbg_f(urb_dev(urb), "regs interrupt ignored\n");
 319 out:
 320         spin_unlock(&intr->lock);
 321 }
 322
 323 static inline void handle_retry_failed_int(struct urb *urb)
 324 {
 325         struct zd_usb *usb = urb->context;
 326         struct zd_mac *mac = zd_usb_to_mac(usb);
 327         struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);
 328
 329         ieee->stats.tx_errors++;
 330         ieee->ieee_stats.tx_retry_limit_exceeded++;
 331         dev_dbg_f(urb_dev(urb), "retry failed interrupt\n");
 332 }
 333
 334
 335 static void int_urb_complete(struct urb *urb)
 336 {
 337         int r;
 338         struct usb_int_header *hdr;
 339
 340         switch (urb->status) {
 341         case 0:
 342                 break;
 343         case -ESHUTDOWN:
 344         case -EINVAL:
 345         case -ENODEV:
 346         case -ENOENT:
 347         case -ECONNRESET:
 348         case -EPIPE:
 349                 goto kfree;
 350         default:
 351                 goto resubmit;
 352         }
 353
 354         if (urb->actual_length < sizeof(hdr)) {
 355                 dev_dbg_f(urb_dev(urb), "error: urb %p to small\n", urb);
 356                 goto resubmit;
 357         }
 358
 359         hdr = urb->transfer_buffer;
 360         if (hdr->type != USB_INT_TYPE) {
 361                 dev_dbg_f(urb_dev(urb), "error: urb %p wrong type\n", urb);
 362                 goto resubmit;
 363         }
 364
 365         switch (hdr->id) {
 366         case USB_INT_ID_REGS:
 367                 handle_regs_int(urb);
 368                 break;
 369         case USB_INT_ID_RETRY_FAILED:
 370                 handle_retry_failed_int(urb);
 371                 break;
 372         default:
 373                 dev_dbg_f(urb_dev(urb), "error: urb %p unknown id %x\n", urb,
 374                         (unsigned int)hdr->id);
 375                 goto resubmit;
 376         }
 377
 378 resubmit:
 379         r = usb_submit_urb(urb, GFP_ATOMIC);
 380         if (r) {
 381                 dev_dbg_f(urb_dev(urb), "resubmit urb %p\n", urb);
 382                 goto kfree;
 383         }
 384         return;
 385 kfree:
 386         kfree(urb->transfer_buffer);
 387 }
 388
 389 static inline int int_urb_interval(struct usb_device *udev)
 390 {
 391         switch (udev->speed) {
 392         case USB_SPEED_HIGH:
 393                 return 4;
 394         case USB_SPEED_LOW:
 395                 return 10;
 396         case USB_SPEED_FULL:
 397         default:
 398                 return 1;
 399         }
 400 }
 401
 402 static inline int usb_int_enabled(struct zd_usb *usb)
 403 {
 404         unsigned long flags;
 405         struct zd_usb_interrupt *intr = &usb->intr;
 406         struct urb *urb;
 407
 408         spin_lock_irqsave(&intr->lock, flags);
 409         urb = intr->urb;
 410         spin_unlock_irqrestore(&intr->lock, flags);
 411         return urb != NULL;
 412 }
 413
 414 int zd_usb_enable_int(struct zd_usb *usb)
 415 {
 416         int r;
 417         struct usb_device *udev;
 418         struct zd_usb_interrupt *intr = &usb->intr;
 419         void *transfer_buffer = NULL;
 420         struct urb *urb;
 421
 422         dev_dbg_f(zd_usb_dev(usb), "\n");
 423
 424         urb = usb_alloc_urb(0, GFP_KERNEL);
 425         if (!urb) {
 426                 r = -ENOMEM;
 427                 goto out;
 428         }
 429
 430         ZD_ASSERT(!irqs_disabled());
 431         spin_lock_irq(&intr->lock);
 432         if (intr->urb) {
 433                 spin_unlock_irq(&intr->lock);
 434                 r = 0;
 435                 goto error_free_urb;
 436         }
 437         intr->urb = urb;
 438         spin_unlock_irq(&intr->lock);
 439
 440         /* TODO: make it a DMA buffer */
 441         r = -ENOMEM;
 442         transfer_buffer = kmalloc(USB_MAX_EP_INT_BUFFER, GFP_KERNEL);
 443         if (!transfer_buffer) {
 444                 dev_dbg_f(zd_usb_dev(usb),
 445                         "couldn't allocate transfer_buffer\n");
 446                 goto error_set_urb_null;
 447         }
 448
 449         udev = zd_usb_to_usbdev(usb);
 450         usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, EP_INT_IN),
 451                          transfer_buffer, USB_MAX_EP_INT_BUFFER,
 452                          int_urb_complete, usb,
 453                          intr->interval);
 454
 455         dev_dbg_f(zd_usb_dev(usb), "submit urb %p\n", intr->urb);
 456         r = usb_submit_urb(urb, GFP_KERNEL);
 457         if (r) {
 458                 dev_dbg_f(zd_usb_dev(usb),
 459                          "Couldn't submit urb. Error number %d\n", r);
 460                 goto error;
 461         }
 462
 463         return 0;
 464 error:
 465         kfree(transfer_buffer);
 466 error_set_urb_null:
 467         spin_lock_irq(&intr->lock);
 468         intr->urb = NULL;
 469         spin_unlock_irq(&intr->lock);
 470 error_free_urb:
 471         usb_free_urb(urb);
 472 out:
 473         return r;
 474 }
 475
 476 void zd_usb_disable_int(struct zd_usb *usb)
 477 {
 478         unsigned long flags;
 479         struct zd_usb_interrupt *intr = &usb->intr;
 480         struct urb *urb;
 481
 482         spin_lock_irqsave(&intr->lock, flags);
 483         urb = intr->urb;
 484         if (!urb) {
 485                 spin_unlock_irqrestore(&intr->lock, flags);
 486                 return;
 487         }
 488         intr->urb = NULL;
 489         spin_unlock_irqrestore(&intr->lock, flags);
 490
 491         usb_kill_urb(urb);
 492         dev_dbg_f(zd_usb_dev(usb), "urb %p killed\n", urb);
 493         usb_free_urb(urb);
 494 }
 495
 496 static void handle_rx_packet(struct zd_usb *usb, const u8 *buffer,
 497                              unsigned int length)
 498 {
 499         int i;
 500         struct zd_mac *mac = zd_usb_to_mac(usb);
 501         const struct rx_length_info *length_info;
 502
 503         if (length < sizeof(struct rx_length_info)) {
 504                 /* It's not a complete packet anyhow. */
 505                 struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);
 506                 ieee->stats.rx_errors++;
 507                 ieee->stats.rx_length_errors++;
 508                 return;
 509         }
 510         length_info = (struct rx_length_info *)
 511                 (buffer + length - sizeof(struct rx_length_info));
 512
 513         /* It might be that three frames are merged into a single URB
 514          * transaction. We have to check for the length info tag.
 515          *
 516          * While testing we discovered that length_info might be unaligned,
 517          * because if USB transactions are merged, the last packet will not
 518          * be padded. Unaligned access might also happen if the length_info
 519          * structure is not present.
 520          */
 521         if (get_unaligned(&length_info->tag) == cpu_to_le16(RX_LENGTH_INFO_TAG))
 522         {
 523                 unsigned int l, k, n;
 524                 for (i = 0, l = 0;; i++) {
 525                         k = le16_to_cpu(get_unaligned(&length_info->length[i]));
 526                         if (k == 0)
 527                                 return;
 528                         n = l+k;
 529                         if (n > length)
 530                                 return;
 531                         zd_mac_rx_irq(mac, buffer+l, k);
 532                         if (i >= 2)
 533                                 return;
 534                         l = (n+3) & ~3;
 535                 }
 536         } else {
 537                 zd_mac_rx_irq(mac, buffer, length);
 538         }
 539 }
 540
 541 static void rx_urb_complete(struct urb *urb)
 542 {
 543         struct zd_usb *usb;
 544         struct zd_usb_rx *rx;
 545         const u8 *buffer;
 546         unsigned int length;
 547
 548         switch (urb->status) {
 549         case 0:
 550                 break;
 551         case -ESHUTDOWN:
 552         case -EINVAL:
 553         case -ENODEV:
 554         case -ENOENT:
 555         case -ECONNRESET:
 556         case -EPIPE:
 557                 return;
 558         default:
 559                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 560                 goto resubmit;
 561         }
 562
 563         buffer = urb->transfer_buffer;
 564         length = urb->actual_length;
 565         usb = urb->context;
 566         rx = &usb->rx;
 567
 568         if (length%rx->usb_packet_size > rx->usb_packet_size-4) {
 569                 /* If there is an old first fragment, we don't care. */
 570                 dev_dbg_f(urb_dev(urb), "*** first fragment ***\n");
 571                 ZD_ASSERT(length <= ARRAY_SIZE(rx->fragment));
 572                 spin_lock(&rx->lock);
 573                 memcpy(rx->fragment, buffer, length);
 574                 rx->fragment_length = length;
 575                 spin_unlock(&rx->lock);
 576                 goto resubmit;
 577         }
 578
 579         spin_lock(&rx->lock);
 580         if (rx->fragment_length > 0) {
 581                 /* We are on a second fragment, we believe */
 582                 ZD_ASSERT(length + rx->fragment_length <=
 583                           ARRAY_SIZE(rx->fragment));
 584                 dev_dbg_f(urb_dev(urb), "*** second fragment ***\n");
 585                 memcpy(rx->fragment+rx->fragment_length, buffer, length);
 586                 handle_rx_packet(usb, rx->fragment,
 587                                  rx->fragment_length + length);
 588                 rx->fragment_length = 0;
 589                 spin_unlock(&rx->lock);
 590         } else {
 591                 spin_unlock(&rx->lock);
 592                 handle_rx_packet(usb, buffer, length);
 593         }
 594
 595 resubmit:
 596         usb_submit_urb(urb, GFP_ATOMIC);
 597 }
 598
 599 static struct urb *alloc_urb(struct zd_usb *usb)
 600 {
 601         struct usb_device *udev = zd_usb_to_usbdev(usb);
 602         struct urb *urb;
 603         void *buffer;
 604
 605         urb = usb_alloc_urb(0, GFP_KERNEL);
 606         if (!urb)
 607                 return NULL;
 608         buffer = usb_buffer_alloc(udev, USB_MAX_RX_SIZE, GFP_KERNEL,
 609                                   &urb->transfer_dma);
 610         if (!buffer) {
 611                 usb_free_urb(urb);
 612                 return NULL;
 613         }
 614
 615         usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_DATA_IN),
 616                           buffer, USB_MAX_RX_SIZE,
 617                           rx_urb_complete, usb);
 618         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 619
 620         return urb;
 621 }
 622
 623 static void free_urb(struct urb *urb)
 624 {
 625         if (!urb)
 626                 return;
 627         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 628                         urb->transfer_buffer, urb->transfer_dma);
 629         usb_free_urb(urb);
 630 }
 631
 632 int zd_usb_enable_rx(struct zd_usb *usb)
 633 {
 634         int i, r;
 635         struct zd_usb_rx *rx = &usb->rx;
 636         struct urb **urbs;
 637
 638         dev_dbg_f(zd_usb_dev(usb), "\n");
 639
 640         r = -ENOMEM;
 641         urbs = kcalloc(URBS_COUNT, sizeof(struct urb *), GFP_KERNEL);
 642         if (!urbs)
 643                 goto error;
 644         for (i = 0; i < URBS_COUNT; i++) {
 645                 urbs[i] = alloc_urb(usb);
 646                 if (!urbs[i])
 647                         goto error;
 648         }
 649
 650         ZD_ASSERT(!irqs_disabled());
 651         spin_lock_irq(&rx->lock);
 652         if (rx->urbs) {
 653                 spin_unlock_irq(&rx->lock);
 654                 r = 0;
 655                 goto error;
 656         }
 657         rx->urbs = urbs;
 658         rx->urbs_count = URBS_COUNT;
 659         spin_unlock_irq(&rx->lock);
 660
 661         for (i = 0; i < URBS_COUNT; i++) {
 662                 r = usb_submit_urb(urbs[i], GFP_KERNEL);
 663                 if (r)
 664                         goto error_submit;
 665         }
 666
 667         return 0;
 668 error_submit:
 669         for (i = 0; i < URBS_COUNT; i++) {
 670                 usb_kill_urb(urbs[i]);
 671         }
 672         spin_lock_irq(&rx->lock);
 673         rx->urbs = NULL;
 674         rx->urbs_count = 0;
 675         spin_unlock_irq(&rx->lock);
 676 error:
 677         if (urbs) {
 678                 for (i = 0; i < URBS_COUNT; i++)
 679                         free_urb(urbs[i]);
 680         }
 681         return r;
 682 }
 683
 684 void zd_usb_disable_rx(struct zd_usb *usb)
 685 {
 686         int i;
 687         unsigned long flags;
 688         struct urb **urbs;
 689         unsigned int count;
 690         struct zd_usb_rx *rx = &usb->rx;
 691
 692         spin_lock_irqsave(&rx->lock, flags);
 693         urbs = rx->urbs;
 694         count = rx->urbs_count;
 695         spin_unlock_irqrestore(&rx->lock, flags);
 696         if (!urbs)
 697                 return;
 698
 699         for (i = 0; i < count; i++) {
 700                 usb_kill_urb(urbs[i]);
 701                 free_urb(urbs[i]);
 702         }
 703         kfree(urbs);
 704
 705         spin_lock_irqsave(&rx->lock, flags);
 706         rx->urbs = NULL;
 707         rx->urbs_count = 0;
 708         spin_unlock_irqrestore(&rx->lock, flags);
 709 }
 710
 711 static void tx_urb_complete(struct urb *urb)
 712 {
 713         int r;
 714
 715         switch (urb->status) {
 716         case 0:
 717                 break;
 718         case -ESHUTDOWN:
 719         case -EINVAL:
 720         case -ENODEV:
 721         case -ENOENT:
 722         case -ECONNRESET:
 723         case -EPIPE:
 724                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 725                 break;
 726         default:
 727                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 728                 goto resubmit;
 729         }
 730 free_urb:
 731         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 732                         urb->transfer_buffer, urb->transfer_dma);
 733         usb_free_urb(urb);
 734         return;
 735 resubmit:
 736         r = usb_submit_urb(urb, GFP_ATOMIC);
 737         if (r) {
 738                 dev_dbg_f(urb_dev(urb), "error resubmit urb %p %d\n", urb, r);
 739                 goto free_urb;
 740         }
 741 }
 742
 743 /* Puts the frame on the USB endpoint. It doesn't wait for
 744  * completion. The frame must contain the control set.
 745  */
 746 int zd_usb_tx(struct zd_usb *usb, const u8 *frame, unsigned int length)
 747 {
 748         int r;
 749         struct usb_device *udev = zd_usb_to_usbdev(usb);
 750         struct urb *urb;
 751         void *buffer;
 752
 753         urb = usb_alloc_urb(0, GFP_ATOMIC);
 754         if (!urb) {
 755                 r = -ENOMEM;
 756                 goto out;
 757         }
 758
 759         buffer = usb_buffer_alloc(zd_usb_to_usbdev(usb), length, GFP_ATOMIC,
 760                                   &urb->transfer_dma);
 761         if (!buffer) {
 762                 r = -ENOMEM;
 763                 goto error_free_urb;
 764         }
 765         memcpy(buffer, frame, length);
 766
 767         usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, EP_DATA_OUT),
 768                           buffer, length, tx_urb_complete, NULL);
 769         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 770
 771         r = usb_submit_urb(urb, GFP_ATOMIC);
 772         if (r)
 773                 goto error;
 774         return 0;
 775 error:
 776         usb_buffer_free(zd_usb_to_usbdev(usb), length, buffer,
 777                         urb->transfer_dma);
 778 error_free_urb:
 779         usb_free_urb(urb);
 780 out:
 781         return r;
 782 }
 783
 784 static inline void init_usb_interrupt(struct zd_usb *usb)
 785 {
 786         struct zd_usb_interrupt *intr = &usb->intr;
 787
 788         spin_lock_init(&intr->lock);
 789         intr->interval = int_urb_interval(zd_usb_to_usbdev(usb));
 790         init_completion(&intr->read_regs.completion);
 791         intr->read_regs.cr_int_addr = cpu_to_le16((u16)CR_INTERRUPT);
 792 }
 793
 794 static inline void init_usb_rx(struct zd_usb *usb)
 795 {
 796         struct zd_usb_rx *rx = &usb->rx;
 797         spin_lock_init(&rx->lock);
 798         if (interface_to_usbdev(usb->intf)->speed == USB_SPEED_HIGH) {
 799                 rx->usb_packet_size = 512;
 800         } else {
 801                 rx->usb_packet_size = 64;
 802         }
 803         ZD_ASSERT(rx->fragment_length == 0);
 804 }
 805
 806 static inline void init_usb_tx(struct zd_usb *usb)
 807 {
 808         /* FIXME: at this point we will allocate a fixed number of urb's for
 809          * use in a cyclic scheme */
 810 }
 811
 812 void zd_usb_init(struct zd_usb *usb, struct net_device *netdev,
 813                  struct usb_interface *intf)
 814 {
 815         memset(usb, 0, sizeof(*usb));
 816         usb->intf = usb_get_intf(intf);
 817         usb_set_intfdata(usb->intf, netdev);
 818         init_usb_interrupt(usb);
 819         init_usb_tx(usb);
 820         init_usb_rx(usb);
 821 }
 822
 823 void zd_usb_clear(struct zd_usb *usb)
 824 {
 825         usb_set_intfdata(usb->intf, NULL);
 826         usb_put_intf(usb->intf);
 827         ZD_MEMCLEAR(usb, sizeof(*usb));
 828         /* FIXME: usb_interrupt, usb_tx, usb_rx? */
 829 }
 830
 831 static const char *speed(enum usb_device_speed speed)
 832 {
 833         switch (speed) {
 834         case USB_SPEED_LOW:
 835                 return "low";
 836         case USB_SPEED_FULL:
 837                 return "full";
 838         case USB_SPEED_HIGH:
 839                 return "high";
 840         default:
 841                 return "unknown speed";
 842         }
 843 }
 844
 845 static int scnprint_id(struct usb_device *udev, char *buffer, size_t size)
 846 {
 847         return scnprintf(buffer, size, "%04hx:%04hx v%04hx %s",
 848                 le16_to_cpu(udev->descriptor.idVendor),
 849                 le16_to_cpu(udev->descriptor.idProduct),
 850                 get_bcdDevice(udev),
 851                 speed(udev->speed));
 852 }
 853
 854 int zd_usb_scnprint_id(struct zd_usb *usb, char *buffer, size_t size)
 855 {
 856         struct usb_device *udev = interface_to_usbdev(usb->intf);
 857         return scnprint_id(udev, buffer, size);
 858 }
 859
 860 #ifdef DEBUG
 861 static void print_id(struct usb_device *udev)
 862 {
 863         char buffer[40];
 864
 865         scnprint_id(udev, buffer, sizeof(buffer));
 866         buffer[sizeof(buffer)-1] = 0;
 867         dev_dbg_f(&udev->dev, "%s\n", buffer);
 868 }
 869 #else
 870 #define print_id(udev) do { } while (0)
 871 #endif
 872
 873 static int eject_installer(struct usb_interface *intf)
 874 {
 875         struct usb_device *udev = interface_to_usbdev(intf);
 876         struct usb_host_interface *iface_desc = &intf->altsetting[0];
 877         struct usb_endpoint_descriptor *endpoint;
 878         unsigned char *cmd;
 879         u8 bulk_out_ep;
 880         int r;
 881
 882         /* Find bulk out endpoint */
 883         endpoint = &iface_desc->endpoint[1].desc;
 884         if ((endpoint->bEndpointAddress & USB_TYPE_MASK) == USB_DIR_OUT &&
 885             (endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
 886             USB_ENDPOINT_XFER_BULK) {
 887                 bulk_out_ep = endpoint->bEndpointAddress;
 888         } else {
 889                 dev_err(&udev->dev,
 890                         "zd1211rw: Could not find bulk out endpoint\n");
 891                 return -ENODEV;
 892         }
 893
 894         cmd = kzalloc(31, GFP_KERNEL);
 895         if (cmd == NULL)
 896                 return -ENODEV;
 897
 898         /* USB bulk command block */
 899         cmd[0] = 0x55;  /* bulk command signature */
 900         cmd[1] = 0x53;  /* bulk command signature */
 901         cmd[2] = 0x42;  /* bulk command signature */
 902         cmd[3] = 0x43;  /* bulk command signature */
 903         cmd[14] = 6;    /* command length */
 904
 905         cmd[15] = 0x1b; /* SCSI command: START STOP UNIT */
 906         cmd[19] = 0x2;  /* eject disc */
 907
 908         dev_info(&udev->dev, "Ejecting virtual installer media...\n");
 909         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, bulk_out_ep),
 910                 cmd, 31, NULL, 2000);
 911         kfree(cmd);
 912         if (r)
 913                 return r;
 914
 915         /* At this point, the device disconnects and reconnects with the real
 916          * ID numbers. */
 917
 918         usb_set_intfdata(intf, NULL);
 919         return 0;
 920 }
 921
 922 static int probe(struct usb_interface *intf, const struct usb_device_id *id)
 923 {
 924         int r;
 925         struct usb_device *udev = interface_to_usbdev(intf);
 926         struct net_device *netdev = NULL;
 927
 928         print_id(udev);
 929
 930         if (id->driver_info & DEVICE_INSTALLER)
 931                 return eject_installer(intf);
 932
 933         switch (udev->speed) {
 934         case USB_SPEED_LOW:
 935         case USB_SPEED_FULL:
 936         case USB_SPEED_HIGH:
 937                 break;
 938         default:
 939                 dev_dbg_f(&intf->dev, "Unknown USB speed\n");
 940                 r = -ENODEV;
 941                 goto error;
 942         }
 943
 944         usb_reset_device(interface_to_usbdev(intf));
 945
 946         netdev = zd_netdev_alloc(intf);
 947         if (netdev == NULL) {
 948                 r = -ENOMEM;
 949                 goto error;
 950         }
 951
 952         r = upload_firmware(udev, id->driver_info);
 953         if (r) {
 954                 dev_err(&intf->dev,
 955                        "couldn't load firmware. Error number %d\n", r);
 956                 goto error;
 957         }
 958
 959         r = usb_reset_configuration(udev);
 960         if (r) {
 961                 dev_dbg_f(&intf->dev,
 962                         "couldn't reset configuration. Error number %d\n", r);
 963                 goto error;
 964         }
 965
 966         /* At this point the interrupt endpoint is not generally enabled. We
 967          * save the USB bandwidth until the network device is opened. But
 968          * notify that the initialization of the MAC will require the
 969          * interrupts to be temporary enabled.
 970          */
 971         r = zd_mac_init_hw(zd_netdev_mac(netdev), id->driver_info);
 972         if (r) {
 973                 dev_dbg_f(&intf->dev,
 974                          "couldn't initialize mac. Error number %d\n", r);
 975                 goto error;
 976         }
 977
 978         r = register_netdev(netdev);
 979         if (r) {
 980                 dev_dbg_f(&intf->dev,
 981                          "couldn't register netdev. Error number %d\n", r);
 982                 goto error;
 983         }
 984
 985         dev_dbg_f(&intf->dev, "successful\n");
 986         dev_info(&intf->dev,"%s\n", netdev->name);
 987         return 0;
 988 error:
 989         usb_reset_device(interface_to_usbdev(intf));
 990         zd_netdev_free(netdev);
 991         return r;
 992 }
 993
 994 static void disconnect(struct usb_interface *intf)
 995 {
 996         struct net_device *netdev = zd_intf_to_netdev(intf);
 997         struct zd_mac *mac = zd_netdev_mac(netdev);
 998         struct zd_usb *usb = &mac->chip.usb;
 999
1000         /* Either something really bad happened, or we're just dealing with
1001          * a DEVICE_INSTALLER. */
1002         if (netdev == NULL)
1003                 return;
1004
1005         dev_dbg_f(zd_usb_dev(usb), "\n");
1006
1007         zd_netdev_disconnect(netdev);
1008
1009         /* Just in case something has gone wrong! */
1010         zd_usb_disable_rx(usb);
1011         zd_usb_disable_int(usb);
1012
1013         /* If the disconnect has been caused by a removal of the
1014          * driver module, the reset allows reloading of the driver. If the
1015          * reset will not be executed here, the upload of the firmware in the
1016          * probe function caused by the reloading of the driver will fail.
1017          */
1018         usb_reset_device(interface_to_usbdev(intf));
1019
1020         zd_netdev_free(netdev);
1021         dev_dbg(&intf->dev, "disconnected\n");
1022 }
1023
1024 static struct usb_driver driver = {
1025         .name           = "zd1211rw",
1026         .id_table       = usb_ids,
1027         .probe          = probe,
1028         .disconnect     = disconnect,
1029 };
1030
1031 struct workqueue_struct *zd_workqueue;
1032
1033 static int __init usb_init(void)
1034 {
1035         int r;
1036
1037         pr_debug("%s usb_init()\n", driver.name);
1038
1039         zd_workqueue = create_singlethread_workqueue(driver.name);
1040         if (zd_workqueue == NULL) {
1041                 printk(KERN_ERR "%s couldn't create workqueue\n", driver.name);
1042                 return -ENOMEM;
1043         }
1044
1045         r = usb_register(&driver);
1046         if (r) {
1047                 destroy_workqueue(zd_workqueue);
1048                 printk(KERN_ERR "%s usb_register() failed. Error number %d\n",
1049                        driver.name, r);
1050                 return r;
1051         }
1052
1053         pr_debug("%s initialized\n", driver.name);
1054         return 0;
1055 }
1056
1057 static void __exit usb_exit(void)
1058 {
1059         pr_debug("%s usb_exit()\n", driver.name);
1060         usb_deregister(&driver);
1061         destroy_workqueue(zd_workqueue);
1062 }
1063
1064 module_init(usb_init);
1065 module_exit(usb_exit);
1066
1067 static int usb_int_regs_length(unsigned int count)
1068 {
1069         return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data);
1070 }
1071
1072 static void prepare_read_regs_int(struct zd_usb *usb)
1073 {
1074         struct zd_usb_interrupt *intr = &usb->intr;
1075
1076         spin_lock_irq(&intr->lock);
1077         intr->read_regs_enabled = 1;
1078         INIT_COMPLETION(intr->read_regs.completion);
1079         spin_unlock_irq(&intr->lock);
1080 }
1081
1082 static void disable_read_regs_int(struct zd_usb *usb)
1083 {
1084         struct zd_usb_interrupt *intr = &usb->intr;
1085
1086         spin_lock_irq(&intr->lock);
1087         intr->read_regs_enabled = 0;
1088         spin_unlock_irq(&intr->lock);
1089 }
1090
1091 static int get_results(struct zd_usb *usb, u16 *values,
1092                        struct usb_req_read_regs *req, unsigned int count)
1093 {
1094         int r;
1095         int i;
1096         struct zd_usb_interrupt *intr = &usb->intr;
1097         struct read_regs_int *rr = &intr->read_regs;
1098         struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
1099
1100         spin_lock_irq(&intr->lock);
1101
1102         r = -EIO;
1103         /* The created block size seems to be larger than expected.
1104          * However results appear to be correct.
1105          */
1106         if (rr->length < usb_int_regs_length(count)) {
1107                 dev_dbg_f(zd_usb_dev(usb),
1108                          "error: actual length %d less than expected %d\n",
1109                          rr->length, usb_int_regs_length(count));
1110                 goto error_unlock;
1111         }
1112         if (rr->length > sizeof(rr->buffer)) {
1113                 dev_dbg_f(zd_usb_dev(usb),
1114                          "error: actual length %d exceeds buffer size %zu\n",
1115                          rr->length, sizeof(rr->buffer));
1116                 goto error_unlock;
1117         }
1118
1119         for (i = 0; i < count; i++) {
1120                 struct reg_data *rd = &regs->regs[i];
1121                 if (rd->addr != req->addr[i]) {
1122                         dev_dbg_f(zd_usb_dev(usb),
1123                                  "rd[%d] addr %#06hx expected %#06hx\n", i,
1124                                  le16_to_cpu(rd->addr),
1125                                  le16_to_cpu(req->addr[i]));
1126                         goto error_unlock;
1127                 }
1128                 values[i] = le16_to_cpu(rd->value);
1129         }
1130
1131         r = 0;
1132 error_unlock:
1133         spin_unlock_irq(&intr->lock);
1134         return r;
1135 }
1136
1137 int zd_usb_ioread16v(struct zd_usb *usb, u16 *values,
1138                      const zd_addr_t *addresses, unsigned int count)
1139 {
1140         int r;
1141         int i, req_len, actual_req_len;
1142         struct usb_device *udev;
1143         struct usb_req_read_regs *req = NULL;
1144         unsigned long timeout;
1145
1146         if (count < 1) {
1147                 dev_dbg_f(zd_usb_dev(usb), "error: count is zero\n");
1148                 return -EINVAL;
1149         }
1150         if (count > USB_MAX_IOREAD16_COUNT) {
1151                 dev_dbg_f(zd_usb_dev(usb),
1152                          "error: count %u exceeds possible max %u\n",
1153                          count, USB_MAX_IOREAD16_COUNT);
1154                 return -EINVAL;
1155         }
1156         if (in_atomic()) {
1157                 dev_dbg_f(zd_usb_dev(usb),
1158                          "error: io in atomic context not supported\n");
1159                 return -EWOULDBLOCK;
1160         }
1161         if (!usb_int_enabled(usb)) {
1162                  dev_dbg_f(zd_usb_dev(usb),
1163                           "error: usb interrupt not enabled\n");
1164                 return -EWOULDBLOCK;
1165         }
1166
1167         req_len = sizeof(struct usb_req_read_regs) + count * sizeof(__le16);
1168         req = kmalloc(req_len, GFP_KERNEL);
1169         if (!req)
1170                 return -ENOMEM;
1171         req->id = cpu_to_le16(USB_REQ_READ_REGS);
1172         for (i = 0; i < count; i++)
1173                 req->addr[i] = cpu_to_le16((u16)addresses[i]);
1174
1175         udev = zd_usb_to_usbdev(usb);
1176         prepare_read_regs_int(usb);
1177         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1178                          req, req_len, &actual_req_len, 1000 /* ms */);
1179         if (r) {
1180                 dev_dbg_f(zd_usb_dev(usb),
1181                         "error in usb_bulk_msg(). Error number %d\n", r);
1182                 goto error;
1183         }
1184         if (req_len != actual_req_len) {
1185                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()\n"
1186                         " req_len %d != actual_req_len %d\n",
1187                         req_len, actual_req_len);
1188                 r = -EIO;
1189                 goto error;
1190         }
1191
1192         timeout = wait_for_completion_timeout(&usb->intr.read_regs.completion,
1193                                               msecs_to_jiffies(1000));
1194         if (!timeout) {
1195                 disable_read_regs_int(usb);
1196                 dev_dbg_f(zd_usb_dev(usb), "read timed out\n");
1197                 r = -ETIMEDOUT;
1198                 goto error;
1199         }
1200
1201         r = get_results(usb, values, req, count);
1202 error:
1203         kfree(req);
1204         return r;
1205 }
1206
1207 int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
1208                       unsigned int count)
1209 {
1210         int r;
1211         struct usb_device *udev;
1212         struct usb_req_write_regs *req = NULL;
1213         int i, req_len, actual_req_len;
1214
1215         if (count == 0)
1216                 return 0;
1217         if (count > USB_MAX_IOWRITE16_COUNT) {
1218                 dev_dbg_f(zd_usb_dev(usb),
1219                         "error: count %u exceeds possible max %u\n",
1220                         count, USB_MAX_IOWRITE16_COUNT);
1221                 return -EINVAL;
1222         }
1223         if (in_atomic()) {
1224                 dev_dbg_f(zd_usb_dev(usb),
1225                         "error: io in atomic context not supported\n");
1226                 return -EWOULDBLOCK;
1227         }
1228
1229         req_len = sizeof(struct usb_req_write_regs) +
1230                   count * sizeof(struct reg_data);
1231         req = kmalloc(req_len, GFP_KERNEL);
1232         if (!req)
1233                 return -ENOMEM;
1234
1235         req->id = cpu_to_le16(USB_REQ_WRITE_REGS);
1236         for (i = 0; i < count; i++) {
1237                 struct reg_data *rw  = &req->reg_writes[i];
1238                 rw->addr = cpu_to_le16((u16)ioreqs[i].addr);
1239                 rw->value = cpu_to_le16(ioreqs[i].value);
1240         }
1241
1242         udev = zd_usb_to_usbdev(usb);
1243         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1244                          req, req_len, &actual_req_len, 1000 /* ms */);
1245         if (r) {
1246                 dev_dbg_f(zd_usb_dev(usb),
1247                         "error in usb_bulk_msg(). Error number %d\n", r);
1248                 goto error;
1249         }
1250         if (req_len != actual_req_len) {
1251                 dev_dbg_f(zd_usb_dev(usb),
1252                         "error in usb_bulk_msg()"
1253                         " req_len %d != actual_req_len %d\n",
1254                         req_len, actual_req_len);
1255                 r = -EIO;
1256                 goto error;
1257         }
1258
1259         /* FALL-THROUGH with r == 0 */
1260 error:
1261         kfree(req);
1262         return r;
1263 }
1264
1265 int zd_usb_rfwrite(struct zd_usb *usb, u32 value, u8 bits)
1266 {
1267         int r;
1268         struct usb_device *udev;
1269         struct usb_req_rfwrite *req = NULL;
1270         int i, req_len, actual_req_len;
1271         u16 bit_value_template;
1272
1273         if (in_atomic()) {
1274                 dev_dbg_f(zd_usb_dev(usb),
1275                         "error: io in atomic context not supported\n");
1276                 return -EWOULDBLOCK;
1277         }
1278         if (bits < USB_MIN_RFWRITE_BIT_COUNT) {
1279                 dev_dbg_f(zd_usb_dev(usb),
1280                         "error: bits %d are smaller than"
1281                         " USB_MIN_RFWRITE_BIT_COUNT %d\n",
1282                         bits, USB_MIN_RFWRITE_BIT_COUNT);
1283                 return -EINVAL;
1284         }
1285         if (bits > USB_MAX_RFWRITE_BIT_COUNT) {
1286                 dev_dbg_f(zd_usb_dev(usb),
1287                         "error: bits %d exceed USB_MAX_RFWRITE_BIT_COUNT %d\n",
1288                         bits, USB_MAX_RFWRITE_BIT_COUNT);
1289                 return -EINVAL;
1290         }
1291 #ifdef DEBUG
1292         if (value & (~0UL << bits)) {
1293                 dev_dbg_f(zd_usb_dev(usb),
1294                         "error: value %#09x has bits >= %d set\n",
1295                         value, bits);
1296                 return -EINVAL;
1297         }
1298 #endif /* DEBUG */
1299
1300         dev_dbg_f(zd_usb_dev(usb), "value %#09x bits %d\n", value, bits);
1301
1302         r = zd_usb_ioread16(usb, &bit_value_template, CR203);
1303         if (r) {
1304                 dev_dbg_f(zd_usb_dev(usb),
1305                         "error %d: Couldn't read CR203\n", r);
1306                 goto out;
1307         }
1308         bit_value_template &= ~(RF_IF_LE|RF_CLK|RF_DATA);
1309
1310         req_len = sizeof(struct usb_req_rfwrite) + bits * sizeof(__le16);
1311         req = kmalloc(req_len, GFP_KERNEL);
1312         if (!req)
1313                 return -ENOMEM;
1314
1315         req->id = cpu_to_le16(USB_REQ_WRITE_RF);
1316         /* 1: 3683a, but not used in ZYDAS driver */
1317         req->value = cpu_to_le16(2);
1318         req->bits = cpu_to_le16(bits);
1319
1320         for (i = 0; i < bits; i++) {
1321                 u16 bv = bit_value_template;
1322                 if (value & (1 << (bits-1-i)))
1323                         bv |= RF_DATA;
1324                 req->bit_values[i] = cpu_to_le16(bv);
1325         }
1326
1327         udev = zd_usb_to_usbdev(usb);
1328         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1329                          req, req_len, &actual_req_len, 1000 /* ms */);
1330         if (r) {
1331                 dev_dbg_f(zd_usb_dev(usb),
1332                         "error in usb_bulk_msg(). Error number %d\n", r);
1333                 goto out;
1334         }
1335         if (req_len != actual_req_len) {
1336                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()"
1337                         " req_len %d != actual_req_len %d\n",
1338                         req_len, actual_req_len);
1339                 r = -EIO;
1340                 goto out;
1341         }
1342
1343         /* FALL-THROUGH with r == 0 */
1344 out:
1345         kfree(req);
1346         return r;
1347 }