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 <net/ieee80211.h>
  28
  29 #include "zd_def.h"
  30 #include "zd_netdev.h"
  31 #include "zd_mac.h"
  32 #include "zd_usb.h"
  33 #include "zd_util.h"
  34
  35 static struct usb_device_id usb_ids[] = {
  36         /* ZD1211 */
  37         { USB_DEVICE(0x0ace, 0x1211), .driver_info = DEVICE_ZD1211 },
  38         { USB_DEVICE(0x07b8, 0x6001), .driver_info = DEVICE_ZD1211 },
  39         { USB_DEVICE(0x126f, 0xa006), .driver_info = DEVICE_ZD1211 },
  40         { USB_DEVICE(0x6891, 0xa727), .driver_info = DEVICE_ZD1211 },
  41         { USB_DEVICE(0x0df6, 0x9071), .driver_info = DEVICE_ZD1211 },
  42         { USB_DEVICE(0x157e, 0x300b), .driver_info = DEVICE_ZD1211 },
  43         { USB_DEVICE(0x079b, 0x004a), .driver_info = DEVICE_ZD1211 },
  44         { USB_DEVICE(0x1740, 0x2000), .driver_info = DEVICE_ZD1211 },
  45         { USB_DEVICE(0x157e, 0x3204), .driver_info = DEVICE_ZD1211 },
  46         { USB_DEVICE(0x0586, 0x3402), .driver_info = DEVICE_ZD1211 },
  47         /* ZD1211B */
  48         { USB_DEVICE(0x0ace, 0x1215), .driver_info = DEVICE_ZD1211B },
  49         { USB_DEVICE(0x157e, 0x300d), .driver_info = DEVICE_ZD1211B },
  50         { USB_DEVICE(0x079b, 0x0062), .driver_info = DEVICE_ZD1211B },
  51         /* "Driverless" devices that need ejecting */
  52         { USB_DEVICE(0x0ace, 0x2011), .driver_info = DEVICE_INSTALLER },
  53         {}
  54 };
  55
  56 MODULE_LICENSE("GPL");
  57 MODULE_DESCRIPTION("USB driver for devices with the ZD1211 chip.");
  58 MODULE_AUTHOR("Ulrich Kunitz");
  59 MODULE_AUTHOR("Daniel Drake");
  60 MODULE_VERSION("1.0");
  61 MODULE_DEVICE_TABLE(usb, usb_ids);
  62
  63 #define FW_ZD1211_PREFIX        "zd1211/zd1211_"
  64 #define FW_ZD1211B_PREFIX       "zd1211/zd1211b_"
  65
  66 /* register address handling */
  67
  68 #ifdef DEBUG
  69 static int check_addr(struct zd_usb *usb, zd_addr_t addr)
  70 {
  71         u32 base = ZD_ADDR_BASE(addr);
  72         u32 offset = ZD_OFFSET(addr);
  73
  74         if ((u32)addr & ADDR_ZERO_MASK)
  75                 goto invalid_address;
  76         switch (base) {
  77         case USB_BASE:
  78                 break;
  79         case CR_BASE:
  80                 if (offset > CR_MAX_OFFSET) {
  81                         dev_dbg(zd_usb_dev(usb),
  82                                 "CR offset %#010x larger than"
  83                                 " CR_MAX_OFFSET %#10x\n",
  84                                 offset, CR_MAX_OFFSET);
  85                         goto invalid_address;
  86                 }
  87                 if (offset & 1) {
  88                         dev_dbg(zd_usb_dev(usb),
  89                                 "CR offset %#010x is not a multiple of 2\n",
  90                                 offset);
  91                         goto invalid_address;
  92                 }
  93                 break;
  94         case E2P_BASE:
  95                 if (offset > E2P_MAX_OFFSET) {
  96                         dev_dbg(zd_usb_dev(usb),
  97                                 "E2P offset %#010x larger than"
  98                                 " E2P_MAX_OFFSET %#010x\n",
  99                                 offset, E2P_MAX_OFFSET);
 100                         goto invalid_address;
 101                 }
 102                 break;
 103         case FW_BASE:
 104                 if (!usb->fw_base_offset) {
 105                         dev_dbg(zd_usb_dev(usb),
 106                                "ERROR: fw base offset has not been set\n");
 107                         return -EAGAIN;
 108                 }
 109                 if (offset > FW_MAX_OFFSET) {
 110                         dev_dbg(zd_usb_dev(usb),
 111                                 "FW offset %#10x is larger than"
 112                                 " FW_MAX_OFFSET %#010x\n",
 113                                 offset, FW_MAX_OFFSET);
 114                         goto invalid_address;
 115                 }
 116                 break;
 117         default:
 118                 dev_dbg(zd_usb_dev(usb),
 119                         "address has unsupported base %#010x\n", addr);
 120                 goto invalid_address;
 121         }
 122
 123         return 0;
 124 invalid_address:
 125         dev_dbg(zd_usb_dev(usb),
 126                 "ERROR: invalid address: %#010x\n", addr);
 127         return -EINVAL;
 128 }
 129 #endif /* DEBUG */
 130
 131 static u16 usb_addr(struct zd_usb *usb, zd_addr_t addr)
 132 {
 133         u32 base;
 134         u16 offset;
 135
 136         base = ZD_ADDR_BASE(addr);
 137         offset = ZD_OFFSET(addr);
 138
 139         ZD_ASSERT(check_addr(usb, addr) == 0);
 140
 141         switch (base) {
 142         case CR_BASE:
 143                 offset += CR_BASE_OFFSET;
 144                 break;
 145         case E2P_BASE:
 146                 offset += E2P_BASE_OFFSET;
 147                 break;
 148         case FW_BASE:
 149                 offset += usb->fw_base_offset;
 150                 break;
 151         }
 152
 153         return offset;
 154 }
 155
 156 /* USB device initialization */
 157
 158 static int request_fw_file(
 159         const struct firmware **fw, const char *name, struct device *device)
 160 {
 161         int r;
 162
 163         dev_dbg_f(device, "fw name %s\n", name);
 164
 165         r = request_firmware(fw, name, device);
 166         if (r)
 167                 dev_err(device,
 168                        "Could not load firmware file %s. Error number %d\n",
 169                        name, r);
 170         return r;
 171 }
 172
 173 static inline u16 get_bcdDevice(const struct usb_device *udev)
 174 {
 175         return le16_to_cpu(udev->descriptor.bcdDevice);
 176 }
 177
 178 enum upload_code_flags {
 179         REBOOT = 1,
 180 };
 181
 182 /* Ensures that MAX_TRANSFER_SIZE is even. */
 183 #define MAX_TRANSFER_SIZE (USB_MAX_TRANSFER_SIZE & ~1)
 184
 185 static int upload_code(struct usb_device *udev,
 186         const u8 *data, size_t size, u16 code_offset, int flags)
 187 {
 188         u8 *p;
 189         int r;
 190
 191         /* USB request blocks need "kmalloced" buffers.
 192          */
 193         p = kmalloc(MAX_TRANSFER_SIZE, GFP_KERNEL);
 194         if (!p) {
 195                 dev_err(&udev->dev, "out of memory\n");
 196                 r = -ENOMEM;
 197                 goto error;
 198         }
 199
 200         size &= ~1;
 201         while (size > 0) {
 202                 size_t transfer_size = size <= MAX_TRANSFER_SIZE ?
 203                         size : MAX_TRANSFER_SIZE;
 204
 205                 dev_dbg_f(&udev->dev, "transfer size %zu\n", transfer_size);
 206
 207                 memcpy(p, data, transfer_size);
 208                 r = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 209                         USB_REQ_FIRMWARE_DOWNLOAD,
 210                         USB_DIR_OUT | USB_TYPE_VENDOR,
 211                         code_offset, 0, p, transfer_size, 1000 /* ms */);
 212                 if (r < 0) {
 213                         dev_err(&udev->dev,
 214                                "USB control request for firmware upload"
 215                                " failed. Error number %d\n", r);
 216                         goto error;
 217                 }
 218                 transfer_size = r & ~1;
 219
 220                 size -= transfer_size;
 221                 data += transfer_size;
 222                 code_offset += transfer_size/sizeof(u16);
 223         }
 224
 225         if (flags & REBOOT) {
 226                 u8 ret;
 227
 228                 r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
 229                         USB_REQ_FIRMWARE_CONFIRM,
 230                         USB_DIR_IN | USB_TYPE_VENDOR,
 231                         0, 0, &ret, sizeof(ret), 5000 /* ms */);
 232                 if (r != sizeof(ret)) {
 233                         dev_err(&udev->dev,
 234                                 "control request firmeware confirmation failed."
 235                                 " Return value %d\n", r);
 236                         if (r >= 0)
 237                                 r = -ENODEV;
 238                         goto error;
 239                 }
 240                 if (ret & 0x80) {
 241                         dev_err(&udev->dev,
 242                                 "Internal error while downloading."
 243                                 " Firmware confirm return value %#04x\n",
 244                                 (unsigned int)ret);
 245                         r = -ENODEV;
 246                         goto error;
 247                 }
 248                 dev_dbg_f(&udev->dev, "firmware confirm return value %#04x\n",
 249                         (unsigned int)ret);
 250         }
 251
 252         r = 0;
 253 error:
 254         kfree(p);
 255         return r;
 256 }
 257
 258 static u16 get_word(const void *data, u16 offset)
 259 {
 260         const __le16 *p = data;
 261         return le16_to_cpu(p[offset]);
 262 }
 263
 264 static char *get_fw_name(char *buffer, size_t size, u8 device_type,
 265                        const char* postfix)
 266 {
 267         scnprintf(buffer, size, "%s%s",
 268                 device_type == DEVICE_ZD1211B ?
 269                         FW_ZD1211B_PREFIX : FW_ZD1211_PREFIX,
 270                 postfix);
 271         return buffer;
 272 }
 273
 274 static int handle_version_mismatch(struct usb_device *udev, u8 device_type,
 275         const struct firmware *ub_fw)
 276 {
 277         const struct firmware *ur_fw = NULL;
 278         int offset;
 279         int r = 0;
 280         char fw_name[128];
 281
 282         r = request_fw_file(&ur_fw,
 283                 get_fw_name(fw_name, sizeof(fw_name), device_type, "ur"),
 284                 &udev->dev);
 285         if (r)
 286                 goto error;
 287
 288         r = upload_code(udev, ur_fw->data, ur_fw->size, FW_START_OFFSET,
 289                 REBOOT);
 290         if (r)
 291                 goto error;
 292
 293         offset = ((EEPROM_REGS_OFFSET + EEPROM_REGS_SIZE) * sizeof(u16));
 294         r = upload_code(udev, ub_fw->data + offset, ub_fw->size - offset,
 295                 E2P_BASE_OFFSET + EEPROM_REGS_SIZE, REBOOT);
 296
 297         /* At this point, the vendor driver downloads the whole firmware
 298          * image, hacks around with version IDs, and uploads it again,
 299          * completely overwriting the boot code. We do not do this here as
 300          * it is not required on any tested devices, and it is suspected to
 301          * cause problems. */
 302 error:
 303         release_firmware(ur_fw);
 304         return r;
 305 }
 306
 307 static int upload_firmware(struct usb_device *udev, u8 device_type)
 308 {
 309         int r;
 310         u16 fw_bcdDevice;
 311         u16 bcdDevice;
 312         const struct firmware *ub_fw = NULL;
 313         const struct firmware *uph_fw = NULL;
 314         char fw_name[128];
 315
 316         bcdDevice = get_bcdDevice(udev);
 317
 318         r = request_fw_file(&ub_fw,
 319                 get_fw_name(fw_name, sizeof(fw_name), device_type,  "ub"),
 320                 &udev->dev);
 321         if (r)
 322                 goto error;
 323
 324         fw_bcdDevice = get_word(ub_fw->data, EEPROM_REGS_OFFSET);
 325
 326         if (fw_bcdDevice != bcdDevice) {
 327                 dev_info(&udev->dev,
 328                         "firmware version %#06x and device bootcode version "
 329                         "%#06x differ\n", fw_bcdDevice, bcdDevice);
 330                 if (bcdDevice <= 0x4313)
 331                         dev_warn(&udev->dev, "device has old bootcode, please "
 332                                 "report success or failure\n");
 333
 334                 r = handle_version_mismatch(udev, device_type, ub_fw);
 335                 if (r)
 336                         goto error;
 337         } else {
 338                 dev_dbg_f(&udev->dev,
 339                         "firmware device id %#06x is equal to the "
 340                         "actual device id\n", fw_bcdDevice);
 341         }
 342
 343
 344         r = request_fw_file(&uph_fw,
 345                 get_fw_name(fw_name, sizeof(fw_name), device_type, "uphr"),
 346                 &udev->dev);
 347         if (r)
 348                 goto error;
 349
 350         r = upload_code(udev, uph_fw->data, uph_fw->size, FW_START_OFFSET,
 351                         REBOOT);
 352         if (r) {
 353                 dev_err(&udev->dev,
 354                         "Could not upload firmware code uph. Error number %d\n",
 355                         r);
 356         }
 357
 358         /* FALL-THROUGH */
 359 error:
 360         release_firmware(ub_fw);
 361         release_firmware(uph_fw);
 362         return r;
 363 }
 364
 365 static void disable_read_regs_int(struct zd_usb *usb)
 366 {
 367         struct zd_usb_interrupt *intr = &usb->intr;
 368
 369         spin_lock(&intr->lock);
 370         intr->read_regs_enabled = 0;
 371         spin_unlock(&intr->lock);
 372 }
 373
 374 #define urb_dev(urb) (&(urb)->dev->dev)
 375
 376 static inline void handle_regs_int(struct urb *urb)
 377 {
 378         struct zd_usb *usb = urb->context;
 379         struct zd_usb_interrupt *intr = &usb->intr;
 380         int len;
 381
 382         ZD_ASSERT(in_interrupt());
 383         spin_lock(&intr->lock);
 384
 385         if (intr->read_regs_enabled) {
 386                 intr->read_regs.length = len = urb->actual_length;
 387
 388                 if (len > sizeof(intr->read_regs.buffer))
 389                         len = sizeof(intr->read_regs.buffer);
 390                 memcpy(intr->read_regs.buffer, urb->transfer_buffer, len);
 391                 intr->read_regs_enabled = 0;
 392                 complete(&intr->read_regs.completion);
 393                 goto out;
 394         }
 395
 396         dev_dbg_f(urb_dev(urb), "regs interrupt ignored\n");
 397 out:
 398         spin_unlock(&intr->lock);
 399 }
 400
 401 static inline void handle_retry_failed_int(struct urb *urb)
 402 {
 403         dev_dbg_f(urb_dev(urb), "retry failed interrupt\n");
 404 }
 405
 406
 407 static void int_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
 408 {
 409         int r;
 410         struct usb_int_header *hdr;
 411
 412         switch (urb->status) {
 413         case 0:
 414                 break;
 415         case -ESHUTDOWN:
 416         case -EINVAL:
 417         case -ENODEV:
 418         case -ENOENT:
 419         case -ECONNRESET:
 420         case -EPIPE:
 421                 goto kfree;
 422         default:
 423                 goto resubmit;
 424         }
 425
 426         if (urb->actual_length < sizeof(hdr)) {
 427                 dev_dbg_f(urb_dev(urb), "error: urb %p to small\n", urb);
 428                 goto resubmit;
 429         }
 430
 431         hdr = urb->transfer_buffer;
 432         if (hdr->type != USB_INT_TYPE) {
 433                 dev_dbg_f(urb_dev(urb), "error: urb %p wrong type\n", urb);
 434                 goto resubmit;
 435         }
 436
 437         switch (hdr->id) {
 438         case USB_INT_ID_REGS:
 439                 handle_regs_int(urb);
 440                 break;
 441         case USB_INT_ID_RETRY_FAILED:
 442                 handle_retry_failed_int(urb);
 443                 break;
 444         default:
 445                 dev_dbg_f(urb_dev(urb), "error: urb %p unknown id %x\n", urb,
 446                         (unsigned int)hdr->id);
 447                 goto resubmit;
 448         }
 449
 450 resubmit:
 451         r = usb_submit_urb(urb, GFP_ATOMIC);
 452         if (r) {
 453                 dev_dbg_f(urb_dev(urb), "resubmit urb %p\n", urb);
 454                 goto kfree;
 455         }
 456         return;
 457 kfree:
 458         kfree(urb->transfer_buffer);
 459 }
 460
 461 static inline int int_urb_interval(struct usb_device *udev)
 462 {
 463         switch (udev->speed) {
 464         case USB_SPEED_HIGH:
 465                 return 4;
 466         case USB_SPEED_LOW:
 467                 return 10;
 468         case USB_SPEED_FULL:
 469         default:
 470                 return 1;
 471         }
 472 }
 473
 474 static inline int usb_int_enabled(struct zd_usb *usb)
 475 {
 476         unsigned long flags;
 477         struct zd_usb_interrupt *intr = &usb->intr;
 478         struct urb *urb;
 479
 480         spin_lock_irqsave(&intr->lock, flags);
 481         urb = intr->urb;
 482         spin_unlock_irqrestore(&intr->lock, flags);
 483         return urb != NULL;
 484 }
 485
 486 int zd_usb_enable_int(struct zd_usb *usb)
 487 {
 488         int r;
 489         struct usb_device *udev;
 490         struct zd_usb_interrupt *intr = &usb->intr;
 491         void *transfer_buffer = NULL;
 492         struct urb *urb;
 493
 494         dev_dbg_f(zd_usb_dev(usb), "\n");
 495
 496         urb = usb_alloc_urb(0, GFP_NOFS);
 497         if (!urb) {
 498                 r = -ENOMEM;
 499                 goto out;
 500         }
 501
 502         ZD_ASSERT(!irqs_disabled());
 503         spin_lock_irq(&intr->lock);
 504         if (intr->urb) {
 505                 spin_unlock_irq(&intr->lock);
 506                 r = 0;
 507                 goto error_free_urb;
 508         }
 509         intr->urb = urb;
 510         spin_unlock_irq(&intr->lock);
 511
 512         /* TODO: make it a DMA buffer */
 513         r = -ENOMEM;
 514         transfer_buffer = kmalloc(USB_MAX_EP_INT_BUFFER, GFP_NOFS);
 515         if (!transfer_buffer) {
 516                 dev_dbg_f(zd_usb_dev(usb),
 517                         "couldn't allocate transfer_buffer\n");
 518                 goto error_set_urb_null;
 519         }
 520
 521         udev = zd_usb_to_usbdev(usb);
 522         usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, EP_INT_IN),
 523                          transfer_buffer, USB_MAX_EP_INT_BUFFER,
 524                          int_urb_complete, usb,
 525                          intr->interval);
 526
 527         dev_dbg_f(zd_usb_dev(usb), "submit urb %p\n", intr->urb);
 528         r = usb_submit_urb(urb, GFP_NOFS);
 529         if (r) {
 530                 dev_dbg_f(zd_usb_dev(usb),
 531                          "Couldn't submit urb. Error number %d\n", r);
 532                 goto error;
 533         }
 534
 535         return 0;
 536 error:
 537         kfree(transfer_buffer);
 538 error_set_urb_null:
 539         spin_lock_irq(&intr->lock);
 540         intr->urb = NULL;
 541         spin_unlock_irq(&intr->lock);
 542 error_free_urb:
 543         usb_free_urb(urb);
 544 out:
 545         return r;
 546 }
 547
 548 void zd_usb_disable_int(struct zd_usb *usb)
 549 {
 550         unsigned long flags;
 551         struct zd_usb_interrupt *intr = &usb->intr;
 552         struct urb *urb;
 553
 554         spin_lock_irqsave(&intr->lock, flags);
 555         urb = intr->urb;
 556         if (!urb) {
 557                 spin_unlock_irqrestore(&intr->lock, flags);
 558                 return;
 559         }
 560         intr->urb = NULL;
 561         spin_unlock_irqrestore(&intr->lock, flags);
 562
 563         usb_kill_urb(urb);
 564         dev_dbg_f(zd_usb_dev(usb), "urb %p killed\n", urb);
 565         usb_free_urb(urb);
 566 }
 567
 568 static void handle_rx_packet(struct zd_usb *usb, const u8 *buffer,
 569                              unsigned int length)
 570 {
 571         int i;
 572         struct zd_mac *mac = zd_usb_to_mac(usb);
 573         const struct rx_length_info *length_info;
 574
 575         if (length < sizeof(struct rx_length_info)) {
 576                 /* It's not a complete packet anyhow. */
 577                 return;
 578         }
 579         length_info = (struct rx_length_info *)
 580                 (buffer + length - sizeof(struct rx_length_info));
 581
 582         /* It might be that three frames are merged into a single URB
 583          * transaction. We have to check for the length info tag.
 584          *
 585          * While testing we discovered that length_info might be unaligned,
 586          * because if USB transactions are merged, the last packet will not
 587          * be padded. Unaligned access might also happen if the length_info
 588          * structure is not present.
 589          */
 590         if (get_unaligned(&length_info->tag) == cpu_to_le16(RX_LENGTH_INFO_TAG))
 591         {
 592                 unsigned int l, k, n;
 593                 for (i = 0, l = 0;; i++) {
 594                         k = le16_to_cpu(get_unaligned(&length_info->length[i]));
 595                         n = l+k;
 596                         if (n > length)
 597                                 return;
 598                         zd_mac_rx(mac, buffer+l, k);
 599                         if (i >= 2)
 600                                 return;
 601                         l = (n+3) & ~3;
 602                 }
 603         } else {
 604                 zd_mac_rx(mac, buffer, length);
 605         }
 606 }
 607
 608 static void rx_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
 609 {
 610         struct zd_usb *usb;
 611         struct zd_usb_rx *rx;
 612         const u8 *buffer;
 613         unsigned int length;
 614
 615         switch (urb->status) {
 616         case 0:
 617                 break;
 618         case -ESHUTDOWN:
 619         case -EINVAL:
 620         case -ENODEV:
 621         case -ENOENT:
 622         case -ECONNRESET:
 623         case -EPIPE:
 624                 return;
 625         default:
 626                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 627                 goto resubmit;
 628         }
 629
 630         buffer = urb->transfer_buffer;
 631         length = urb->actual_length;
 632         usb = urb->context;
 633         rx = &usb->rx;
 634
 635         if (length%rx->usb_packet_size > rx->usb_packet_size-4) {
 636                 /* If there is an old first fragment, we don't care. */
 637                 dev_dbg_f(urb_dev(urb), "*** first fragment ***\n");
 638                 ZD_ASSERT(length <= ARRAY_SIZE(rx->fragment));
 639                 spin_lock(&rx->lock);
 640                 memcpy(rx->fragment, buffer, length);
 641                 rx->fragment_length = length;
 642                 spin_unlock(&rx->lock);
 643                 goto resubmit;
 644         }
 645
 646         spin_lock(&rx->lock);
 647         if (rx->fragment_length > 0) {
 648                 /* We are on a second fragment, we believe */
 649                 ZD_ASSERT(length + rx->fragment_length <=
 650                           ARRAY_SIZE(rx->fragment));
 651                 dev_dbg_f(urb_dev(urb), "*** second fragment ***\n");
 652                 memcpy(rx->fragment+rx->fragment_length, buffer, length);
 653                 handle_rx_packet(usb, rx->fragment,
 654                                  rx->fragment_length + length);
 655                 rx->fragment_length = 0;
 656                 spin_unlock(&rx->lock);
 657         } else {
 658                 spin_unlock(&rx->lock);
 659                 handle_rx_packet(usb, buffer, length);
 660         }
 661
 662 resubmit:
 663         usb_submit_urb(urb, GFP_ATOMIC);
 664 }
 665
 666 struct urb *alloc_urb(struct zd_usb *usb)
 667 {
 668         struct usb_device *udev = zd_usb_to_usbdev(usb);
 669         struct urb *urb;
 670         void *buffer;
 671
 672         urb = usb_alloc_urb(0, GFP_NOFS);
 673         if (!urb)
 674                 return NULL;
 675         buffer = usb_buffer_alloc(udev, USB_MAX_RX_SIZE, GFP_NOFS,
 676                                   &urb->transfer_dma);
 677         if (!buffer) {
 678                 usb_free_urb(urb);
 679                 return NULL;
 680         }
 681
 682         usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_DATA_IN),
 683                           buffer, USB_MAX_RX_SIZE,
 684                           rx_urb_complete, usb);
 685         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 686
 687         return urb;
 688 }
 689
 690 void free_urb(struct urb *urb)
 691 {
 692         if (!urb)
 693                 return;
 694         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 695                         urb->transfer_buffer, urb->transfer_dma);
 696         usb_free_urb(urb);
 697 }
 698
 699 int zd_usb_enable_rx(struct zd_usb *usb)
 700 {
 701         int i, r;
 702         struct zd_usb_rx *rx = &usb->rx;
 703         struct urb **urbs;
 704
 705         dev_dbg_f(zd_usb_dev(usb), "\n");
 706
 707         r = -ENOMEM;
 708         urbs = kcalloc(URBS_COUNT, sizeof(struct urb *), GFP_NOFS);
 709         if (!urbs)
 710                 goto error;
 711         for (i = 0; i < URBS_COUNT; i++) {
 712                 urbs[i] = alloc_urb(usb);
 713                 if (!urbs[i])
 714                         goto error;
 715         }
 716
 717         ZD_ASSERT(!irqs_disabled());
 718         spin_lock_irq(&rx->lock);
 719         if (rx->urbs) {
 720                 spin_unlock_irq(&rx->lock);
 721                 r = 0;
 722                 goto error;
 723         }
 724         rx->urbs = urbs;
 725         rx->urbs_count = URBS_COUNT;
 726         spin_unlock_irq(&rx->lock);
 727
 728         for (i = 0; i < URBS_COUNT; i++) {
 729                 r = usb_submit_urb(urbs[i], GFP_NOFS);
 730                 if (r)
 731                         goto error_submit;
 732         }
 733
 734         return 0;
 735 error_submit:
 736         for (i = 0; i < URBS_COUNT; i++) {
 737                 usb_kill_urb(urbs[i]);
 738         }
 739         spin_lock_irq(&rx->lock);
 740         rx->urbs = NULL;
 741         rx->urbs_count = 0;
 742         spin_unlock_irq(&rx->lock);
 743 error:
 744         if (urbs) {
 745                 for (i = 0; i < URBS_COUNT; i++)
 746                         free_urb(urbs[i]);
 747         }
 748         return r;
 749 }
 750
 751 void zd_usb_disable_rx(struct zd_usb *usb)
 752 {
 753         int i;
 754         unsigned long flags;
 755         struct urb **urbs;
 756         unsigned int count;
 757         struct zd_usb_rx *rx = &usb->rx;
 758
 759         spin_lock_irqsave(&rx->lock, flags);
 760         urbs = rx->urbs;
 761         count = rx->urbs_count;
 762         spin_unlock_irqrestore(&rx->lock, flags);
 763         if (!urbs)
 764                 return;
 765
 766         for (i = 0; i < count; i++) {
 767                 usb_kill_urb(urbs[i]);
 768                 free_urb(urbs[i]);
 769         }
 770         kfree(urbs);
 771
 772         spin_lock_irqsave(&rx->lock, flags);
 773         rx->urbs = NULL;
 774         rx->urbs_count = 0;
 775         spin_unlock_irqrestore(&rx->lock, flags);
 776 }
 777
 778 static void tx_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
 779 {
 780         int r;
 781
 782         switch (urb->status) {
 783         case 0:
 784                 break;
 785         case -ESHUTDOWN:
 786         case -EINVAL:
 787         case -ENODEV:
 788         case -ENOENT:
 789         case -ECONNRESET:
 790         case -EPIPE:
 791                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 792                 break;
 793         default:
 794                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 795                 goto resubmit;
 796         }
 797 free_urb:
 798         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 799                         urb->transfer_buffer, urb->transfer_dma);
 800         usb_free_urb(urb);
 801         return;
 802 resubmit:
 803         r = usb_submit_urb(urb, GFP_ATOMIC);
 804         if (r) {
 805                 dev_dbg_f(urb_dev(urb), "error resubmit urb %p %d\n", urb, r);
 806                 goto free_urb;
 807         }
 808 }
 809
 810 /* Puts the frame on the USB endpoint. It doesn't wait for
 811  * completion. The frame must contain the control set.
 812  */
 813 int zd_usb_tx(struct zd_usb *usb, const u8 *frame, unsigned int length)
 814 {
 815         int r;
 816         struct usb_device *udev = zd_usb_to_usbdev(usb);
 817         struct urb *urb;
 818         void *buffer;
 819
 820         urb = usb_alloc_urb(0, GFP_ATOMIC);
 821         if (!urb) {
 822                 r = -ENOMEM;
 823                 goto out;
 824         }
 825
 826         buffer = usb_buffer_alloc(zd_usb_to_usbdev(usb), length, GFP_ATOMIC,
 827                                   &urb->transfer_dma);
 828         if (!buffer) {
 829                 r = -ENOMEM;
 830                 goto error_free_urb;
 831         }
 832         memcpy(buffer, frame, length);
 833
 834         usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, EP_DATA_OUT),
 835                           buffer, length, tx_urb_complete, NULL);
 836         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 837
 838         r = usb_submit_urb(urb, GFP_ATOMIC);
 839         if (r)
 840                 goto error;
 841         return 0;
 842 error:
 843         usb_buffer_free(zd_usb_to_usbdev(usb), length, buffer,
 844                         urb->transfer_dma);
 845 error_free_urb:
 846         usb_free_urb(urb);
 847 out:
 848         return r;
 849 }
 850
 851 static inline void init_usb_interrupt(struct zd_usb *usb)
 852 {
 853         struct zd_usb_interrupt *intr = &usb->intr;
 854
 855         spin_lock_init(&intr->lock);
 856         intr->interval = int_urb_interval(zd_usb_to_usbdev(usb));
 857         init_completion(&intr->read_regs.completion);
 858         intr->read_regs.cr_int_addr = cpu_to_le16(usb_addr(usb, CR_INTERRUPT));
 859 }
 860
 861 static inline void init_usb_rx(struct zd_usb *usb)
 862 {
 863         struct zd_usb_rx *rx = &usb->rx;
 864         spin_lock_init(&rx->lock);
 865         if (interface_to_usbdev(usb->intf)->speed == USB_SPEED_HIGH) {
 866                 rx->usb_packet_size = 512;
 867         } else {
 868                 rx->usb_packet_size = 64;
 869         }
 870         ZD_ASSERT(rx->fragment_length == 0);
 871 }
 872
 873 static inline void init_usb_tx(struct zd_usb *usb)
 874 {
 875         /* FIXME: at this point we will allocate a fixed number of urb's for
 876          * use in a cyclic scheme */
 877 }
 878
 879 void zd_usb_init(struct zd_usb *usb, struct net_device *netdev,
 880                  struct usb_interface *intf)
 881 {
 882         memset(usb, 0, sizeof(*usb));
 883         usb->intf = usb_get_intf(intf);
 884         usb_set_intfdata(usb->intf, netdev);
 885         init_usb_interrupt(usb);
 886         init_usb_tx(usb);
 887         init_usb_rx(usb);
 888 }
 889
 890 int zd_usb_init_hw(struct zd_usb *usb)
 891 {
 892         int r;
 893         struct zd_chip *chip = zd_usb_to_chip(usb);
 894
 895         ZD_ASSERT(mutex_is_locked(&chip->mutex));
 896         r = zd_ioread16_locked(chip, &usb->fw_base_offset,
 897                         USB_REG((u16)FW_BASE_ADDR_OFFSET));
 898         if (r)
 899                 return r;
 900         dev_dbg_f(zd_usb_dev(usb), "fw_base_offset: %#06hx\n",
 901                  usb->fw_base_offset);
 902
 903         return 0;
 904 }
 905
 906 void zd_usb_clear(struct zd_usb *usb)
 907 {
 908         usb_set_intfdata(usb->intf, NULL);
 909         usb_put_intf(usb->intf);
 910         memset(usb, 0, sizeof(*usb));
 911         /* FIXME: usb_interrupt, usb_tx, usb_rx? */
 912 }
 913
 914 static const char *speed(enum usb_device_speed speed)
 915 {
 916         switch (speed) {
 917         case USB_SPEED_LOW:
 918                 return "low";
 919         case USB_SPEED_FULL:
 920                 return "full";
 921         case USB_SPEED_HIGH:
 922                 return "high";
 923         default:
 924                 return "unknown speed";
 925         }
 926 }
 927
 928 static int scnprint_id(struct usb_device *udev, char *buffer, size_t size)
 929 {
 930         return scnprintf(buffer, size, "%04hx:%04hx v%04hx %s",
 931                 le16_to_cpu(udev->descriptor.idVendor),
 932                 le16_to_cpu(udev->descriptor.idProduct),
 933                 get_bcdDevice(udev),
 934                 speed(udev->speed));
 935 }
 936
 937 int zd_usb_scnprint_id(struct zd_usb *usb, char *buffer, size_t size)
 938 {
 939         struct usb_device *udev = interface_to_usbdev(usb->intf);
 940         return scnprint_id(udev, buffer, size);
 941 }
 942
 943 #ifdef DEBUG
 944 static void print_id(struct usb_device *udev)
 945 {
 946         char buffer[40];
 947
 948         scnprint_id(udev, buffer, sizeof(buffer));
 949         buffer[sizeof(buffer)-1] = 0;
 950         dev_dbg_f(&udev->dev, "%s\n", buffer);
 951 }
 952 #else
 953 #define print_id(udev) do { } while (0)
 954 #endif
 955
 956 static int eject_installer(struct usb_interface *intf)
 957 {
 958         struct usb_device *udev = interface_to_usbdev(intf);
 959         struct usb_host_interface *iface_desc = &intf->altsetting[0];
 960         struct usb_endpoint_descriptor *endpoint;
 961         unsigned char *cmd;
 962         u8 bulk_out_ep;
 963         int r;
 964
 965         /* Find bulk out endpoint */
 966         endpoint = &iface_desc->endpoint[1].desc;
 967         if ((endpoint->bEndpointAddress & USB_TYPE_MASK) == USB_DIR_OUT &&
 968             (endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
 969             USB_ENDPOINT_XFER_BULK) {
 970                 bulk_out_ep = endpoint->bEndpointAddress;
 971         } else {
 972                 dev_err(&udev->dev,
 973                         "zd1211rw: Could not find bulk out endpoint\n");
 974                 return -ENODEV;
 975         }
 976
 977         cmd = kzalloc(31, GFP_KERNEL);
 978         if (cmd == NULL)
 979                 return -ENODEV;
 980
 981         /* USB bulk command block */
 982         cmd[0] = 0x55;  /* bulk command signature */
 983         cmd[1] = 0x53;  /* bulk command signature */
 984         cmd[2] = 0x42;  /* bulk command signature */
 985         cmd[3] = 0x43;  /* bulk command signature */
 986         cmd[14] = 6;    /* command length */
 987
 988         cmd[15] = 0x1b; /* SCSI command: START STOP UNIT */
 989         cmd[19] = 0x2;  /* eject disc */
 990
 991         dev_info(&udev->dev, "Ejecting virtual installer media...\n");
 992         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, bulk_out_ep),
 993                 cmd, 31, NULL, 2000);
 994         kfree(cmd);
 995         if (r)
 996                 return r;
 997
 998         /* At this point, the device disconnects and reconnects with the real
 999          * ID numbers. */
1000
1001         usb_set_intfdata(intf, NULL);
1002         return 0;
1003 }
1004
1005 static int probe(struct usb_interface *intf, const struct usb_device_id *id)
1006 {
1007         int r;
1008         struct usb_device *udev = interface_to_usbdev(intf);
1009         struct net_device *netdev = NULL;
1010
1011         print_id(udev);
1012
1013         if (id->driver_info & DEVICE_INSTALLER)
1014                 return eject_installer(intf);
1015
1016         switch (udev->speed) {
1017         case USB_SPEED_LOW:
1018         case USB_SPEED_FULL:
1019         case USB_SPEED_HIGH:
1020                 break;
1021         default:
1022                 dev_dbg_f(&intf->dev, "Unknown USB speed\n");
1023                 r = -ENODEV;
1024                 goto error;
1025         }
1026
1027         netdev = zd_netdev_alloc(intf);
1028         if (netdev == NULL) {
1029                 r = -ENOMEM;
1030                 goto error;
1031         }
1032
1033         r = upload_firmware(udev, id->driver_info);
1034         if (r) {
1035                 dev_err(&intf->dev,
1036                        "couldn't load firmware. Error number %d\n", r);
1037                 goto error;
1038         }
1039
1040         r = usb_reset_configuration(udev);
1041         if (r) {
1042                 dev_dbg_f(&intf->dev,
1043                         "couldn't reset configuration. Error number %d\n", r);
1044                 goto error;
1045         }
1046
1047         /* At this point the interrupt endpoint is not generally enabled. We
1048          * save the USB bandwidth until the network device is opened. But
1049          * notify that the initialization of the MAC will require the
1050          * interrupts to be temporary enabled.
1051          */
1052         r = zd_mac_init_hw(zd_netdev_mac(netdev), id->driver_info);
1053         if (r) {
1054                 dev_dbg_f(&intf->dev,
1055                          "couldn't initialize mac. Error number %d\n", r);
1056                 goto error;
1057         }
1058
1059         r = register_netdev(netdev);
1060         if (r) {
1061                 dev_dbg_f(&intf->dev,
1062                          "couldn't register netdev. Error number %d\n", r);
1063                 goto error;
1064         }
1065
1066         dev_dbg_f(&intf->dev, "successful\n");
1067         dev_info(&intf->dev,"%s\n", netdev->name);
1068         return 0;
1069 error:
1070         usb_reset_device(interface_to_usbdev(intf));
1071         zd_netdev_free(netdev);
1072         return r;
1073 }
1074
1075 static void disconnect(struct usb_interface *intf)
1076 {
1077         struct net_device *netdev = zd_intf_to_netdev(intf);
1078         struct zd_mac *mac = zd_netdev_mac(netdev);
1079         struct zd_usb *usb = &mac->chip.usb;
1080
1081         /* Either something really bad happened, or we're just dealing with
1082          * a DEVICE_INSTALLER. */
1083         if (netdev == NULL)
1084                 return;
1085
1086         dev_dbg_f(zd_usb_dev(usb), "\n");
1087
1088         zd_netdev_disconnect(netdev);
1089
1090         /* Just in case something has gone wrong! */
1091         zd_usb_disable_rx(usb);
1092         zd_usb_disable_int(usb);
1093
1094         /* If the disconnect has been caused by a removal of the
1095          * driver module, the reset allows reloading of the driver. If the
1096          * reset will not be executed here, the upload of the firmware in the
1097          * probe function caused by the reloading of the driver will fail.
1098          */
1099         usb_reset_device(interface_to_usbdev(intf));
1100
1101         /* If somebody still waits on this lock now, this is an error. */
1102         zd_netdev_free(netdev);
1103         dev_dbg(&intf->dev, "disconnected\n");
1104 }
1105
1106 static struct usb_driver driver = {
1107         .name           = "zd1211rw",
1108         .id_table       = usb_ids,
1109         .probe          = probe,
1110         .disconnect     = disconnect,
1111 };
1112
1113 static int __init usb_init(void)
1114 {
1115         int r;
1116
1117         pr_debug("usb_init()\n");
1118
1119         r = usb_register(&driver);
1120         if (r) {
1121                 printk(KERN_ERR "usb_register() failed. Error number %d\n", r);
1122                 return r;
1123         }
1124
1125         pr_debug("zd1211rw initialized\n");
1126         return 0;
1127 }
1128
1129 static void __exit usb_exit(void)
1130 {
1131         pr_debug("usb_exit()\n");
1132         usb_deregister(&driver);
1133 }
1134
1135 module_init(usb_init);
1136 module_exit(usb_exit);
1137
1138 static int usb_int_regs_length(unsigned int count)
1139 {
1140         return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data);
1141 }
1142
1143 static void prepare_read_regs_int(struct zd_usb *usb)
1144 {
1145         struct zd_usb_interrupt *intr = &usb->intr;
1146
1147         spin_lock(&intr->lock);
1148         intr->read_regs_enabled = 1;
1149         INIT_COMPLETION(intr->read_regs.completion);
1150         spin_unlock(&intr->lock);
1151 }
1152
1153 static int get_results(struct zd_usb *usb, u16 *values,
1154                        struct usb_req_read_regs *req, unsigned int count)
1155 {
1156         int r;
1157         int i;
1158         struct zd_usb_interrupt *intr = &usb->intr;
1159         struct read_regs_int *rr = &intr->read_regs;
1160         struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
1161
1162         spin_lock(&intr->lock);
1163
1164         r = -EIO;
1165         /* The created block size seems to be larger than expected.
1166          * However results appear to be correct.
1167          */
1168         if (rr->length < usb_int_regs_length(count)) {
1169                 dev_dbg_f(zd_usb_dev(usb),
1170                          "error: actual length %d less than expected %d\n",
1171                          rr->length, usb_int_regs_length(count));
1172                 goto error_unlock;
1173         }
1174         if (rr->length > sizeof(rr->buffer)) {
1175                 dev_dbg_f(zd_usb_dev(usb),
1176                          "error: actual length %d exceeds buffer size %zu\n",
1177                          rr->length, sizeof(rr->buffer));
1178                 goto error_unlock;
1179         }
1180
1181         for (i = 0; i < count; i++) {
1182                 struct reg_data *rd = &regs->regs[i];
1183                 if (rd->addr != req->addr[i]) {
1184                         dev_dbg_f(zd_usb_dev(usb),
1185                                  "rd[%d] addr %#06hx expected %#06hx\n", i,
1186                                  le16_to_cpu(rd->addr),
1187                                  le16_to_cpu(req->addr[i]));
1188                         goto error_unlock;
1189                 }
1190                 values[i] = le16_to_cpu(rd->value);
1191         }
1192
1193         r = 0;
1194 error_unlock:
1195         spin_unlock(&intr->lock);
1196         return r;
1197 }
1198
1199 int zd_usb_ioread16v(struct zd_usb *usb, u16 *values,
1200                      const zd_addr_t *addresses, unsigned int count)
1201 {
1202         int r;
1203         int i, req_len, actual_req_len;
1204         struct usb_device *udev;
1205         struct usb_req_read_regs *req = NULL;
1206         unsigned long timeout;
1207
1208         if (count < 1) {
1209                 dev_dbg_f(zd_usb_dev(usb), "error: count is zero\n");
1210                 return -EINVAL;
1211         }
1212         if (count > USB_MAX_IOREAD16_COUNT) {
1213                 dev_dbg_f(zd_usb_dev(usb),
1214                          "error: count %u exceeds possible max %u\n",
1215                          count, USB_MAX_IOREAD16_COUNT);
1216                 return -EINVAL;
1217         }
1218         if (in_atomic()) {
1219                 dev_dbg_f(zd_usb_dev(usb),
1220                          "error: io in atomic context not supported\n");
1221                 return -EWOULDBLOCK;
1222         }
1223         if (!usb_int_enabled(usb)) {
1224                  dev_dbg_f(zd_usb_dev(usb),
1225                           "error: usb interrupt not enabled\n");
1226                 return -EWOULDBLOCK;
1227         }
1228
1229         req_len = sizeof(struct usb_req_read_regs) + count * sizeof(__le16);
1230         req = kmalloc(req_len, GFP_NOFS);
1231         if (!req)
1232                 return -ENOMEM;
1233         req->id = cpu_to_le16(USB_REQ_READ_REGS);
1234         for (i = 0; i < count; i++)
1235                 req->addr[i] = cpu_to_le16(usb_addr(usb, addresses[i]));
1236
1237         udev = zd_usb_to_usbdev(usb);
1238         prepare_read_regs_int(usb);
1239         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1240                          req, req_len, &actual_req_len, 1000 /* ms */);
1241         if (r) {
1242                 dev_dbg_f(zd_usb_dev(usb),
1243                         "error in usb_bulk_msg(). Error number %d\n", r);
1244                 goto error;
1245         }
1246         if (req_len != actual_req_len) {
1247                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()\n"
1248                         " req_len %d != actual_req_len %d\n",
1249                         req_len, actual_req_len);
1250                 r = -EIO;
1251                 goto error;
1252         }
1253
1254         timeout = wait_for_completion_timeout(&usb->intr.read_regs.completion,
1255                                               msecs_to_jiffies(1000));
1256         if (!timeout) {
1257                 disable_read_regs_int(usb);
1258                 dev_dbg_f(zd_usb_dev(usb), "read timed out\n");
1259                 r = -ETIMEDOUT;
1260                 goto error;
1261         }
1262
1263         r = get_results(usb, values, req, count);
1264 error:
1265         kfree(req);
1266         return r;
1267 }
1268
1269 int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
1270                       unsigned int count)
1271 {
1272         int r;
1273         struct usb_device *udev;
1274         struct usb_req_write_regs *req = NULL;
1275         int i, req_len, actual_req_len;
1276
1277         if (count == 0)
1278                 return 0;
1279         if (count > USB_MAX_IOWRITE16_COUNT) {
1280                 dev_dbg_f(zd_usb_dev(usb),
1281                         "error: count %u exceeds possible max %u\n",
1282                         count, USB_MAX_IOWRITE16_COUNT);
1283                 return -EINVAL;
1284         }
1285         if (in_atomic()) {
1286                 dev_dbg_f(zd_usb_dev(usb),
1287                         "error: io in atomic context not supported\n");
1288                 return -EWOULDBLOCK;
1289         }
1290
1291         req_len = sizeof(struct usb_req_write_regs) +
1292                   count * sizeof(struct reg_data);
1293         req = kmalloc(req_len, GFP_NOFS);
1294         if (!req)
1295                 return -ENOMEM;
1296
1297         req->id = cpu_to_le16(USB_REQ_WRITE_REGS);
1298         for (i = 0; i < count; i++) {
1299                 struct reg_data *rw  = &req->reg_writes[i];
1300                 rw->addr = cpu_to_le16(usb_addr(usb, ioreqs[i].addr));
1301                 rw->value = cpu_to_le16(ioreqs[i].value);
1302         }
1303
1304         udev = zd_usb_to_usbdev(usb);
1305         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1306                          req, req_len, &actual_req_len, 1000 /* ms */);
1307         if (r) {
1308                 dev_dbg_f(zd_usb_dev(usb),
1309                         "error in usb_bulk_msg(). Error number %d\n", r);
1310                 goto error;
1311         }
1312         if (req_len != actual_req_len) {
1313                 dev_dbg_f(zd_usb_dev(usb),
1314                         "error in usb_bulk_msg()"
1315                         " req_len %d != actual_req_len %d\n",
1316                         req_len, actual_req_len);
1317                 r = -EIO;
1318                 goto error;
1319         }
1320
1321         /* FALL-THROUGH with r == 0 */
1322 error:
1323         kfree(req);
1324         return r;
1325 }
1326
1327 int zd_usb_rfwrite(struct zd_usb *usb, u32 value, u8 bits)
1328 {
1329         int r;
1330         struct usb_device *udev;
1331         struct usb_req_rfwrite *req = NULL;
1332         int i, req_len, actual_req_len;
1333         u16 bit_value_template;
1334
1335         if (in_atomic()) {
1336                 dev_dbg_f(zd_usb_dev(usb),
1337                         "error: io in atomic context not supported\n");
1338                 return -EWOULDBLOCK;
1339         }
1340         if (bits < USB_MIN_RFWRITE_BIT_COUNT) {
1341                 dev_dbg_f(zd_usb_dev(usb),
1342                         "error: bits %d are smaller than"
1343                         " USB_MIN_RFWRITE_BIT_COUNT %d\n",
1344                         bits, USB_MIN_RFWRITE_BIT_COUNT);
1345                 return -EINVAL;
1346         }
1347         if (bits > USB_MAX_RFWRITE_BIT_COUNT) {
1348                 dev_dbg_f(zd_usb_dev(usb),
1349                         "error: bits %d exceed USB_MAX_RFWRITE_BIT_COUNT %d\n",
1350                         bits, USB_MAX_RFWRITE_BIT_COUNT);
1351                 return -EINVAL;
1352         }
1353 #ifdef DEBUG
1354         if (value & (~0UL << bits)) {
1355                 dev_dbg_f(zd_usb_dev(usb),
1356                         "error: value %#09x has bits >= %d set\n",
1357                         value, bits);
1358                 return -EINVAL;
1359         }
1360 #endif /* DEBUG */
1361
1362         dev_dbg_f(zd_usb_dev(usb), "value %#09x bits %d\n", value, bits);
1363
1364         r = zd_usb_ioread16(usb, &bit_value_template, CR203);
1365         if (r) {
1366                 dev_dbg_f(zd_usb_dev(usb),
1367                         "error %d: Couldn't read CR203\n", r);
1368                 goto out;
1369         }
1370         bit_value_template &= ~(RF_IF_LE|RF_CLK|RF_DATA);
1371
1372         req_len = sizeof(struct usb_req_rfwrite) + bits * sizeof(__le16);
1373         req = kmalloc(req_len, GFP_NOFS);
1374         if (!req)
1375                 return -ENOMEM;
1376
1377         req->id = cpu_to_le16(USB_REQ_WRITE_RF);
1378         /* 1: 3683a, but not used in ZYDAS driver */
1379         req->value = cpu_to_le16(2);
1380         req->bits = cpu_to_le16(bits);
1381
1382         for (i = 0; i < bits; i++) {
1383                 u16 bv = bit_value_template;
1384                 if (value & (1 << (bits-1-i)))
1385                         bv |= RF_DATA;
1386                 req->bit_values[i] = cpu_to_le16(bv);
1387         }
1388
1389         udev = zd_usb_to_usbdev(usb);
1390         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1391                          req, req_len, &actual_req_len, 1000 /* ms */);
1392         if (r) {
1393                 dev_dbg_f(zd_usb_dev(usb),
1394                         "error in usb_bulk_msg(). Error number %d\n", r);
1395                 goto out;
1396         }
1397         if (req_len != actual_req_len) {
1398                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()"
1399                         " req_len %d != actual_req_len %d\n",
1400                         req_len, actual_req_len);
1401                 r = -EIO;
1402                 goto out;
1403         }
1404
1405         /* FALL-THROUGH with r == 0 */
1406 out:
1407         kfree(req);
1408         return r;
1409 }