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         { USB_DEVICE(0x1582, 0x6003), .driver_info = DEVICE_ZD1211B },
  52         /* "Driverless" devices that need ejecting */
  53         { USB_DEVICE(0x0ace, 0x2011), .driver_info = DEVICE_INSTALLER },
  54         {}
  55 };
  56
  57 MODULE_LICENSE("GPL");
  58 MODULE_DESCRIPTION("USB driver for devices with the ZD1211 chip.");
  59 MODULE_AUTHOR("Ulrich Kunitz");
  60 MODULE_AUTHOR("Daniel Drake");
  61 MODULE_VERSION("1.0");
  62 MODULE_DEVICE_TABLE(usb, usb_ids);
  63
  64 #define FW_ZD1211_PREFIX        "zd1211/zd1211_"
  65 #define FW_ZD1211B_PREFIX       "zd1211/zd1211b_"
  66
  67 /* register address handling */
  68
  69 #ifdef DEBUG
  70 static int check_addr(struct zd_usb *usb, zd_addr_t addr)
  71 {
  72         u32 base = ZD_ADDR_BASE(addr);
  73         u32 offset = ZD_OFFSET(addr);
  74
  75         if ((u32)addr & ADDR_ZERO_MASK)
  76                 goto invalid_address;
  77         switch (base) {
  78         case USB_BASE:
  79                 break;
  80         case CR_BASE:
  81                 if (offset > CR_MAX_OFFSET) {
  82                         dev_dbg(zd_usb_dev(usb),
  83                                 "CR offset %#010x larger than"
  84                                 " CR_MAX_OFFSET %#10x\n",
  85                                 offset, CR_MAX_OFFSET);
  86                         goto invalid_address;
  87                 }
  88                 if (offset & 1) {
  89                         dev_dbg(zd_usb_dev(usb),
  90                                 "CR offset %#010x is not a multiple of 2\n",
  91                                 offset);
  92                         goto invalid_address;
  93                 }
  94                 break;
  95         case E2P_BASE:
  96                 if (offset > E2P_MAX_OFFSET) {
  97                         dev_dbg(zd_usb_dev(usb),
  98                                 "E2P offset %#010x larger than"
  99                                 " E2P_MAX_OFFSET %#010x\n",
 100                                 offset, E2P_MAX_OFFSET);
 101                         goto invalid_address;
 102                 }
 103                 break;
 104         case FW_BASE:
 105                 if (!usb->fw_base_offset) {
 106                         dev_dbg(zd_usb_dev(usb),
 107                                "ERROR: fw base offset has not been set\n");
 108                         return -EAGAIN;
 109                 }
 110                 if (offset > FW_MAX_OFFSET) {
 111                         dev_dbg(zd_usb_dev(usb),
 112                                 "FW offset %#10x is larger than"
 113                                 " FW_MAX_OFFSET %#010x\n",
 114                                 offset, FW_MAX_OFFSET);
 115                         goto invalid_address;
 116                 }
 117                 break;
 118         default:
 119                 dev_dbg(zd_usb_dev(usb),
 120                         "address has unsupported base %#010x\n", addr);
 121                 goto invalid_address;
 122         }
 123
 124         return 0;
 125 invalid_address:
 126         dev_dbg(zd_usb_dev(usb),
 127                 "ERROR: invalid address: %#010x\n", addr);
 128         return -EINVAL;
 129 }
 130 #endif /* DEBUG */
 131
 132 static u16 usb_addr(struct zd_usb *usb, zd_addr_t addr)
 133 {
 134         u32 base;
 135         u16 offset;
 136
 137         base = ZD_ADDR_BASE(addr);
 138         offset = ZD_OFFSET(addr);
 139
 140         ZD_ASSERT(check_addr(usb, addr) == 0);
 141
 142         switch (base) {
 143         case CR_BASE:
 144                 offset += CR_BASE_OFFSET;
 145                 break;
 146         case E2P_BASE:
 147                 offset += E2P_BASE_OFFSET;
 148                 break;
 149         case FW_BASE:
 150                 offset += usb->fw_base_offset;
 151                 break;
 152         }
 153
 154         return offset;
 155 }
 156
 157 /* USB device initialization */
 158
 159 static int request_fw_file(
 160         const struct firmware **fw, const char *name, struct device *device)
 161 {
 162         int r;
 163
 164         dev_dbg_f(device, "fw name %s\n", name);
 165
 166         r = request_firmware(fw, name, device);
 167         if (r)
 168                 dev_err(device,
 169                        "Could not load firmware file %s. Error number %d\n",
 170                        name, r);
 171         return r;
 172 }
 173
 174 static inline u16 get_bcdDevice(const struct usb_device *udev)
 175 {
 176         return le16_to_cpu(udev->descriptor.bcdDevice);
 177 }
 178
 179 enum upload_code_flags {
 180         REBOOT = 1,
 181 };
 182
 183 /* Ensures that MAX_TRANSFER_SIZE is even. */
 184 #define MAX_TRANSFER_SIZE (USB_MAX_TRANSFER_SIZE & ~1)
 185
 186 static int upload_code(struct usb_device *udev,
 187         const u8 *data, size_t size, u16 code_offset, int flags)
 188 {
 189         u8 *p;
 190         int r;
 191
 192         /* USB request blocks need "kmalloced" buffers.
 193          */
 194         p = kmalloc(MAX_TRANSFER_SIZE, GFP_KERNEL);
 195         if (!p) {
 196                 dev_err(&udev->dev, "out of memory\n");
 197                 r = -ENOMEM;
 198                 goto error;
 199         }
 200
 201         size &= ~1;
 202         while (size > 0) {
 203                 size_t transfer_size = size <= MAX_TRANSFER_SIZE ?
 204                         size : MAX_TRANSFER_SIZE;
 205
 206                 dev_dbg_f(&udev->dev, "transfer size %zu\n", transfer_size);
 207
 208                 memcpy(p, data, transfer_size);
 209                 r = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 210                         USB_REQ_FIRMWARE_DOWNLOAD,
 211                         USB_DIR_OUT | USB_TYPE_VENDOR,
 212                         code_offset, 0, p, transfer_size, 1000 /* ms */);
 213                 if (r < 0) {
 214                         dev_err(&udev->dev,
 215                                "USB control request for firmware upload"
 216                                " failed. Error number %d\n", r);
 217                         goto error;
 218                 }
 219                 transfer_size = r & ~1;
 220
 221                 size -= transfer_size;
 222                 data += transfer_size;
 223                 code_offset += transfer_size/sizeof(u16);
 224         }
 225
 226         if (flags & REBOOT) {
 227                 u8 ret;
 228
 229                 r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
 230                         USB_REQ_FIRMWARE_CONFIRM,
 231                         USB_DIR_IN | USB_TYPE_VENDOR,
 232                         0, 0, &ret, sizeof(ret), 5000 /* ms */);
 233                 if (r != sizeof(ret)) {
 234                         dev_err(&udev->dev,
 235                                 "control request firmeware confirmation failed."
 236                                 " Return value %d\n", r);
 237                         if (r >= 0)
 238                                 r = -ENODEV;
 239                         goto error;
 240                 }
 241                 if (ret & 0x80) {
 242                         dev_err(&udev->dev,
 243                                 "Internal error while downloading."
 244                                 " Firmware confirm return value %#04x\n",
 245                                 (unsigned int)ret);
 246                         r = -ENODEV;
 247                         goto error;
 248                 }
 249                 dev_dbg_f(&udev->dev, "firmware confirm return value %#04x\n",
 250                         (unsigned int)ret);
 251         }
 252
 253         r = 0;
 254 error:
 255         kfree(p);
 256         return r;
 257 }
 258
 259 static u16 get_word(const void *data, u16 offset)
 260 {
 261         const __le16 *p = data;
 262         return le16_to_cpu(p[offset]);
 263 }
 264
 265 static char *get_fw_name(char *buffer, size_t size, u8 device_type,
 266                        const char* postfix)
 267 {
 268         scnprintf(buffer, size, "%s%s",
 269                 device_type == DEVICE_ZD1211B ?
 270                         FW_ZD1211B_PREFIX : FW_ZD1211_PREFIX,
 271                 postfix);
 272         return buffer;
 273 }
 274
 275 static int handle_version_mismatch(struct usb_device *udev, u8 device_type,
 276         const struct firmware *ub_fw)
 277 {
 278         const struct firmware *ur_fw = NULL;
 279         int offset;
 280         int r = 0;
 281         char fw_name[128];
 282
 283         r = request_fw_file(&ur_fw,
 284                 get_fw_name(fw_name, sizeof(fw_name), device_type, "ur"),
 285                 &udev->dev);
 286         if (r)
 287                 goto error;
 288
 289         r = upload_code(udev, ur_fw->data, ur_fw->size, FW_START_OFFSET,
 290                 REBOOT);
 291         if (r)
 292                 goto error;
 293
 294         offset = ((EEPROM_REGS_OFFSET + EEPROM_REGS_SIZE) * sizeof(u16));
 295         r = upload_code(udev, ub_fw->data + offset, ub_fw->size - offset,
 296                 E2P_BASE_OFFSET + EEPROM_REGS_SIZE, REBOOT);
 297
 298         /* At this point, the vendor driver downloads the whole firmware
 299          * image, hacks around with version IDs, and uploads it again,
 300          * completely overwriting the boot code. We do not do this here as
 301          * it is not required on any tested devices, and it is suspected to
 302          * cause problems. */
 303 error:
 304         release_firmware(ur_fw);
 305         return r;
 306 }
 307
 308 static int upload_firmware(struct usb_device *udev, u8 device_type)
 309 {
 310         int r;
 311         u16 fw_bcdDevice;
 312         u16 bcdDevice;
 313         const struct firmware *ub_fw = NULL;
 314         const struct firmware *uph_fw = NULL;
 315         char fw_name[128];
 316
 317         bcdDevice = get_bcdDevice(udev);
 318
 319         r = request_fw_file(&ub_fw,
 320                 get_fw_name(fw_name, sizeof(fw_name), device_type,  "ub"),
 321                 &udev->dev);
 322         if (r)
 323                 goto error;
 324
 325         fw_bcdDevice = get_word(ub_fw->data, EEPROM_REGS_OFFSET);
 326
 327         if (fw_bcdDevice != bcdDevice) {
 328                 dev_info(&udev->dev,
 329                         "firmware version %#06x and device bootcode version "
 330                         "%#06x differ\n", fw_bcdDevice, bcdDevice);
 331                 if (bcdDevice <= 0x4313)
 332                         dev_warn(&udev->dev, "device has old bootcode, please "
 333                                 "report success or failure\n");
 334
 335                 r = handle_version_mismatch(udev, device_type, ub_fw);
 336                 if (r)
 337                         goto error;
 338         } else {
 339                 dev_dbg_f(&udev->dev,
 340                         "firmware device id %#06x is equal to the "
 341                         "actual device id\n", fw_bcdDevice);
 342         }
 343
 344
 345         r = request_fw_file(&uph_fw,
 346                 get_fw_name(fw_name, sizeof(fw_name), device_type, "uphr"),
 347                 &udev->dev);
 348         if (r)
 349                 goto error;
 350
 351         r = upload_code(udev, uph_fw->data, uph_fw->size, FW_START_OFFSET,
 352                         REBOOT);
 353         if (r) {
 354                 dev_err(&udev->dev,
 355                         "Could not upload firmware code uph. Error number %d\n",
 356                         r);
 357         }
 358
 359         /* FALL-THROUGH */
 360 error:
 361         release_firmware(ub_fw);
 362         release_firmware(uph_fw);
 363         return r;
 364 }
 365
 366 static void disable_read_regs_int(struct zd_usb *usb)
 367 {
 368         struct zd_usb_interrupt *intr = &usb->intr;
 369
 370         spin_lock(&intr->lock);
 371         intr->read_regs_enabled = 0;
 372         spin_unlock(&intr->lock);
 373 }
 374
 375 #define urb_dev(urb) (&(urb)->dev->dev)
 376
 377 static inline void handle_regs_int(struct urb *urb)
 378 {
 379         struct zd_usb *usb = urb->context;
 380         struct zd_usb_interrupt *intr = &usb->intr;
 381         int len;
 382
 383         ZD_ASSERT(in_interrupt());
 384         spin_lock(&intr->lock);
 385
 386         if (intr->read_regs_enabled) {
 387                 intr->read_regs.length = len = urb->actual_length;
 388
 389                 if (len > sizeof(intr->read_regs.buffer))
 390                         len = sizeof(intr->read_regs.buffer);
 391                 memcpy(intr->read_regs.buffer, urb->transfer_buffer, len);
 392                 intr->read_regs_enabled = 0;
 393                 complete(&intr->read_regs.completion);
 394                 goto out;
 395         }
 396
 397         dev_dbg_f(urb_dev(urb), "regs interrupt ignored\n");
 398 out:
 399         spin_unlock(&intr->lock);
 400 }
 401
 402 static inline void handle_retry_failed_int(struct urb *urb)
 403 {
 404         dev_dbg_f(urb_dev(urb), "retry failed interrupt\n");
 405 }
 406
 407
 408 static void int_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
 409 {
 410         int r;
 411         struct usb_int_header *hdr;
 412
 413         switch (urb->status) {
 414         case 0:
 415                 break;
 416         case -ESHUTDOWN:
 417         case -EINVAL:
 418         case -ENODEV:
 419         case -ENOENT:
 420         case -ECONNRESET:
 421         case -EPIPE:
 422                 goto kfree;
 423         default:
 424                 goto resubmit;
 425         }
 426
 427         if (urb->actual_length < sizeof(hdr)) {
 428                 dev_dbg_f(urb_dev(urb), "error: urb %p to small\n", urb);
 429                 goto resubmit;
 430         }
 431
 432         hdr = urb->transfer_buffer;
 433         if (hdr->type != USB_INT_TYPE) {
 434                 dev_dbg_f(urb_dev(urb), "error: urb %p wrong type\n", urb);
 435                 goto resubmit;
 436         }
 437
 438         switch (hdr->id) {
 439         case USB_INT_ID_REGS:
 440                 handle_regs_int(urb);
 441                 break;
 442         case USB_INT_ID_RETRY_FAILED:
 443                 handle_retry_failed_int(urb);
 444                 break;
 445         default:
 446                 dev_dbg_f(urb_dev(urb), "error: urb %p unknown id %x\n", urb,
 447                         (unsigned int)hdr->id);
 448                 goto resubmit;
 449         }
 450
 451 resubmit:
 452         r = usb_submit_urb(urb, GFP_ATOMIC);
 453         if (r) {
 454                 dev_dbg_f(urb_dev(urb), "resubmit urb %p\n", urb);
 455                 goto kfree;
 456         }
 457         return;
 458 kfree:
 459         kfree(urb->transfer_buffer);
 460 }
 461
 462 static inline int int_urb_interval(struct usb_device *udev)
 463 {
 464         switch (udev->speed) {
 465         case USB_SPEED_HIGH:
 466                 return 4;
 467         case USB_SPEED_LOW:
 468                 return 10;
 469         case USB_SPEED_FULL:
 470         default:
 471                 return 1;
 472         }
 473 }
 474
 475 static inline int usb_int_enabled(struct zd_usb *usb)
 476 {
 477         unsigned long flags;
 478         struct zd_usb_interrupt *intr = &usb->intr;
 479         struct urb *urb;
 480
 481         spin_lock_irqsave(&intr->lock, flags);
 482         urb = intr->urb;
 483         spin_unlock_irqrestore(&intr->lock, flags);
 484         return urb != NULL;
 485 }
 486
 487 int zd_usb_enable_int(struct zd_usb *usb)
 488 {
 489         int r;
 490         struct usb_device *udev;
 491         struct zd_usb_interrupt *intr = &usb->intr;
 492         void *transfer_buffer = NULL;
 493         struct urb *urb;
 494
 495         dev_dbg_f(zd_usb_dev(usb), "\n");
 496
 497         urb = usb_alloc_urb(0, GFP_NOFS);
 498         if (!urb) {
 499                 r = -ENOMEM;
 500                 goto out;
 501         }
 502
 503         ZD_ASSERT(!irqs_disabled());
 504         spin_lock_irq(&intr->lock);
 505         if (intr->urb) {
 506                 spin_unlock_irq(&intr->lock);
 507                 r = 0;
 508                 goto error_free_urb;
 509         }
 510         intr->urb = urb;
 511         spin_unlock_irq(&intr->lock);
 512
 513         /* TODO: make it a DMA buffer */
 514         r = -ENOMEM;
 515         transfer_buffer = kmalloc(USB_MAX_EP_INT_BUFFER, GFP_NOFS);
 516         if (!transfer_buffer) {
 517                 dev_dbg_f(zd_usb_dev(usb),
 518                         "couldn't allocate transfer_buffer\n");
 519                 goto error_set_urb_null;
 520         }
 521
 522         udev = zd_usb_to_usbdev(usb);
 523         usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, EP_INT_IN),
 524                          transfer_buffer, USB_MAX_EP_INT_BUFFER,
 525                          int_urb_complete, usb,
 526                          intr->interval);
 527
 528         dev_dbg_f(zd_usb_dev(usb), "submit urb %p\n", intr->urb);
 529         r = usb_submit_urb(urb, GFP_NOFS);
 530         if (r) {
 531                 dev_dbg_f(zd_usb_dev(usb),
 532                          "Couldn't submit urb. Error number %d\n", r);
 533                 goto error;
 534         }
 535
 536         return 0;
 537 error:
 538         kfree(transfer_buffer);
 539 error_set_urb_null:
 540         spin_lock_irq(&intr->lock);
 541         intr->urb = NULL;
 542         spin_unlock_irq(&intr->lock);
 543 error_free_urb:
 544         usb_free_urb(urb);
 545 out:
 546         return r;
 547 }
 548
 549 void zd_usb_disable_int(struct zd_usb *usb)
 550 {
 551         unsigned long flags;
 552         struct zd_usb_interrupt *intr = &usb->intr;
 553         struct urb *urb;
 554
 555         spin_lock_irqsave(&intr->lock, flags);
 556         urb = intr->urb;
 557         if (!urb) {
 558                 spin_unlock_irqrestore(&intr->lock, flags);
 559                 return;
 560         }
 561         intr->urb = NULL;
 562         spin_unlock_irqrestore(&intr->lock, flags);
 563
 564         usb_kill_urb(urb);
 565         dev_dbg_f(zd_usb_dev(usb), "urb %p killed\n", urb);
 566         usb_free_urb(urb);
 567 }
 568
 569 static void handle_rx_packet(struct zd_usb *usb, const u8 *buffer,
 570                              unsigned int length)
 571 {
 572         int i;
 573         struct zd_mac *mac = zd_usb_to_mac(usb);
 574         const struct rx_length_info *length_info;
 575
 576         if (length < sizeof(struct rx_length_info)) {
 577                 /* It's not a complete packet anyhow. */
 578                 return;
 579         }
 580         length_info = (struct rx_length_info *)
 581                 (buffer + length - sizeof(struct rx_length_info));
 582
 583         /* It might be that three frames are merged into a single URB
 584          * transaction. We have to check for the length info tag.
 585          *
 586          * While testing we discovered that length_info might be unaligned,
 587          * because if USB transactions are merged, the last packet will not
 588          * be padded. Unaligned access might also happen if the length_info
 589          * structure is not present.
 590          */
 591         if (get_unaligned(&length_info->tag) == cpu_to_le16(RX_LENGTH_INFO_TAG))
 592         {
 593                 unsigned int l, k, n;
 594                 for (i = 0, l = 0;; i++) {
 595                         k = le16_to_cpu(get_unaligned(&length_info->length[i]));
 596                         n = l+k;
 597                         if (n > length)
 598                                 return;
 599                         zd_mac_rx(mac, buffer+l, k);
 600                         if (i >= 2)
 601                                 return;
 602                         l = (n+3) & ~3;
 603                 }
 604         } else {
 605                 zd_mac_rx(mac, buffer, length);
 606         }
 607 }
 608
 609 static void rx_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
 610 {
 611         struct zd_usb *usb;
 612         struct zd_usb_rx *rx;
 613         const u8 *buffer;
 614         unsigned int length;
 615
 616         switch (urb->status) {
 617         case 0:
 618                 break;
 619         case -ESHUTDOWN:
 620         case -EINVAL:
 621         case -ENODEV:
 622         case -ENOENT:
 623         case -ECONNRESET:
 624         case -EPIPE:
 625                 return;
 626         default:
 627                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 628                 goto resubmit;
 629         }
 630
 631         buffer = urb->transfer_buffer;
 632         length = urb->actual_length;
 633         usb = urb->context;
 634         rx = &usb->rx;
 635
 636         if (length%rx->usb_packet_size > rx->usb_packet_size-4) {
 637                 /* If there is an old first fragment, we don't care. */
 638                 dev_dbg_f(urb_dev(urb), "*** first fragment ***\n");
 639                 ZD_ASSERT(length <= ARRAY_SIZE(rx->fragment));
 640                 spin_lock(&rx->lock);
 641                 memcpy(rx->fragment, buffer, length);
 642                 rx->fragment_length = length;
 643                 spin_unlock(&rx->lock);
 644                 goto resubmit;
 645         }
 646
 647         spin_lock(&rx->lock);
 648         if (rx->fragment_length > 0) {
 649                 /* We are on a second fragment, we believe */
 650                 ZD_ASSERT(length + rx->fragment_length <=
 651                           ARRAY_SIZE(rx->fragment));
 652                 dev_dbg_f(urb_dev(urb), "*** second fragment ***\n");
 653                 memcpy(rx->fragment+rx->fragment_length, buffer, length);
 654                 handle_rx_packet(usb, rx->fragment,
 655                                  rx->fragment_length + length);
 656                 rx->fragment_length = 0;
 657                 spin_unlock(&rx->lock);
 658         } else {
 659                 spin_unlock(&rx->lock);
 660                 handle_rx_packet(usb, buffer, length);
 661         }
 662
 663 resubmit:
 664         usb_submit_urb(urb, GFP_ATOMIC);
 665 }
 666
 667 static struct urb *alloc_urb(struct zd_usb *usb)
 668 {
 669         struct usb_device *udev = zd_usb_to_usbdev(usb);
 670         struct urb *urb;
 671         void *buffer;
 672
 673         urb = usb_alloc_urb(0, GFP_NOFS);
 674         if (!urb)
 675                 return NULL;
 676         buffer = usb_buffer_alloc(udev, USB_MAX_RX_SIZE, GFP_NOFS,
 677                                   &urb->transfer_dma);
 678         if (!buffer) {
 679                 usb_free_urb(urb);
 680                 return NULL;
 681         }
 682
 683         usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_DATA_IN),
 684                           buffer, USB_MAX_RX_SIZE,
 685                           rx_urb_complete, usb);
 686         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 687
 688         return urb;
 689 }
 690
 691 static void free_urb(struct urb *urb)
 692 {
 693         if (!urb)
 694                 return;
 695         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 696                         urb->transfer_buffer, urb->transfer_dma);
 697         usb_free_urb(urb);
 698 }
 699
 700 int zd_usb_enable_rx(struct zd_usb *usb)
 701 {
 702         int i, r;
 703         struct zd_usb_rx *rx = &usb->rx;
 704         struct urb **urbs;
 705
 706         dev_dbg_f(zd_usb_dev(usb), "\n");
 707
 708         r = -ENOMEM;
 709         urbs = kcalloc(URBS_COUNT, sizeof(struct urb *), GFP_NOFS);
 710         if (!urbs)
 711                 goto error;
 712         for (i = 0; i < URBS_COUNT; i++) {
 713                 urbs[i] = alloc_urb(usb);
 714                 if (!urbs[i])
 715                         goto error;
 716         }
 717
 718         ZD_ASSERT(!irqs_disabled());
 719         spin_lock_irq(&rx->lock);
 720         if (rx->urbs) {
 721                 spin_unlock_irq(&rx->lock);
 722                 r = 0;
 723                 goto error;
 724         }
 725         rx->urbs = urbs;
 726         rx->urbs_count = URBS_COUNT;
 727         spin_unlock_irq(&rx->lock);
 728
 729         for (i = 0; i < URBS_COUNT; i++) {
 730                 r = usb_submit_urb(urbs[i], GFP_NOFS);
 731                 if (r)
 732                         goto error_submit;
 733         }
 734
 735         return 0;
 736 error_submit:
 737         for (i = 0; i < URBS_COUNT; i++) {
 738                 usb_kill_urb(urbs[i]);
 739         }
 740         spin_lock_irq(&rx->lock);
 741         rx->urbs = NULL;
 742         rx->urbs_count = 0;
 743         spin_unlock_irq(&rx->lock);
 744 error:
 745         if (urbs) {
 746                 for (i = 0; i < URBS_COUNT; i++)
 747                         free_urb(urbs[i]);
 748         }
 749         return r;
 750 }
 751
 752 void zd_usb_disable_rx(struct zd_usb *usb)
 753 {
 754         int i;
 755         unsigned long flags;
 756         struct urb **urbs;
 757         unsigned int count;
 758         struct zd_usb_rx *rx = &usb->rx;
 759
 760         spin_lock_irqsave(&rx->lock, flags);
 761         urbs = rx->urbs;
 762         count = rx->urbs_count;
 763         spin_unlock_irqrestore(&rx->lock, flags);
 764         if (!urbs)
 765                 return;
 766
 767         for (i = 0; i < count; i++) {
 768                 usb_kill_urb(urbs[i]);
 769                 free_urb(urbs[i]);
 770         }
 771         kfree(urbs);
 772
 773         spin_lock_irqsave(&rx->lock, flags);
 774         rx->urbs = NULL;
 775         rx->urbs_count = 0;
 776         spin_unlock_irqrestore(&rx->lock, flags);
 777 }
 778
 779 static void tx_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
 780 {
 781         int r;
 782
 783         switch (urb->status) {
 784         case 0:
 785                 break;
 786         case -ESHUTDOWN:
 787         case -EINVAL:
 788         case -ENODEV:
 789         case -ENOENT:
 790         case -ECONNRESET:
 791         case -EPIPE:
 792                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 793                 break;
 794         default:
 795                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
 796                 goto resubmit;
 797         }
 798 free_urb:
 799         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 800                         urb->transfer_buffer, urb->transfer_dma);
 801         usb_free_urb(urb);
 802         return;
 803 resubmit:
 804         r = usb_submit_urb(urb, GFP_ATOMIC);
 805         if (r) {
 806                 dev_dbg_f(urb_dev(urb), "error resubmit urb %p %d\n", urb, r);
 807                 goto free_urb;
 808         }
 809 }
 810
 811 /* Puts the frame on the USB endpoint. It doesn't wait for
 812  * completion. The frame must contain the control set.
 813  */
 814 int zd_usb_tx(struct zd_usb *usb, const u8 *frame, unsigned int length)
 815 {
 816         int r;
 817         struct usb_device *udev = zd_usb_to_usbdev(usb);
 818         struct urb *urb;
 819         void *buffer;
 820
 821         urb = usb_alloc_urb(0, GFP_ATOMIC);
 822         if (!urb) {
 823                 r = -ENOMEM;
 824                 goto out;
 825         }
 826
 827         buffer = usb_buffer_alloc(zd_usb_to_usbdev(usb), length, GFP_ATOMIC,
 828                                   &urb->transfer_dma);
 829         if (!buffer) {
 830                 r = -ENOMEM;
 831                 goto error_free_urb;
 832         }
 833         memcpy(buffer, frame, length);
 834
 835         usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, EP_DATA_OUT),
 836                           buffer, length, tx_urb_complete, NULL);
 837         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 838
 839         r = usb_submit_urb(urb, GFP_ATOMIC);
 840         if (r)
 841                 goto error;
 842         return 0;
 843 error:
 844         usb_buffer_free(zd_usb_to_usbdev(usb), length, buffer,
 845                         urb->transfer_dma);
 846 error_free_urb:
 847         usb_free_urb(urb);
 848 out:
 849         return r;
 850 }
 851
 852 static inline void init_usb_interrupt(struct zd_usb *usb)
 853 {
 854         struct zd_usb_interrupt *intr = &usb->intr;
 855
 856         spin_lock_init(&intr->lock);
 857         intr->interval = int_urb_interval(zd_usb_to_usbdev(usb));
 858         init_completion(&intr->read_regs.completion);
 859         intr->read_regs.cr_int_addr = cpu_to_le16(usb_addr(usb, CR_INTERRUPT));
 860 }
 861
 862 static inline void init_usb_rx(struct zd_usb *usb)
 863 {
 864         struct zd_usb_rx *rx = &usb->rx;
 865         spin_lock_init(&rx->lock);
 866         if (interface_to_usbdev(usb->intf)->speed == USB_SPEED_HIGH) {
 867                 rx->usb_packet_size = 512;
 868         } else {
 869                 rx->usb_packet_size = 64;
 870         }
 871         ZD_ASSERT(rx->fragment_length == 0);
 872 }
 873
 874 static inline void init_usb_tx(struct zd_usb *usb)
 875 {
 876         /* FIXME: at this point we will allocate a fixed number of urb's for
 877          * use in a cyclic scheme */
 878 }
 879
 880 void zd_usb_init(struct zd_usb *usb, struct net_device *netdev,
 881                  struct usb_interface *intf)
 882 {
 883         memset(usb, 0, sizeof(*usb));
 884         usb->intf = usb_get_intf(intf);
 885         usb_set_intfdata(usb->intf, netdev);
 886         init_usb_interrupt(usb);
 887         init_usb_tx(usb);
 888         init_usb_rx(usb);
 889 }
 890
 891 int zd_usb_init_hw(struct zd_usb *usb)
 892 {
 893         int r;
 894         struct zd_chip *chip = zd_usb_to_chip(usb);
 895
 896         ZD_ASSERT(mutex_is_locked(&chip->mutex));
 897         r = zd_ioread16_locked(chip, &usb->fw_base_offset,
 898                         USB_REG((u16)FW_BASE_ADDR_OFFSET));
 899         if (r)
 900                 return r;
 901         dev_dbg_f(zd_usb_dev(usb), "fw_base_offset: %#06hx\n",
 902                  usb->fw_base_offset);
 903
 904         return 0;
 905 }
 906
 907 void zd_usb_clear(struct zd_usb *usb)
 908 {
 909         usb_set_intfdata(usb->intf, NULL);
 910         usb_put_intf(usb->intf);
 911         ZD_MEMCLEAR(usb, sizeof(*usb));
 912         /* FIXME: usb_interrupt, usb_tx, usb_rx? */
 913 }
 914
 915 static const char *speed(enum usb_device_speed speed)
 916 {
 917         switch (speed) {
 918         case USB_SPEED_LOW:
 919                 return "low";
 920         case USB_SPEED_FULL:
 921                 return "full";
 922         case USB_SPEED_HIGH:
 923                 return "high";
 924         default:
 925                 return "unknown speed";
 926         }
 927 }
 928
 929 static int scnprint_id(struct usb_device *udev, char *buffer, size_t size)
 930 {
 931         return scnprintf(buffer, size, "%04hx:%04hx v%04hx %s",
 932                 le16_to_cpu(udev->descriptor.idVendor),
 933                 le16_to_cpu(udev->descriptor.idProduct),
 934                 get_bcdDevice(udev),
 935                 speed(udev->speed));
 936 }
 937
 938 int zd_usb_scnprint_id(struct zd_usb *usb, char *buffer, size_t size)
 939 {
 940         struct usb_device *udev = interface_to_usbdev(usb->intf);
 941         return scnprint_id(udev, buffer, size);
 942 }
 943
 944 #ifdef DEBUG
 945 static void print_id(struct usb_device *udev)
 946 {
 947         char buffer[40];
 948
 949         scnprint_id(udev, buffer, sizeof(buffer));
 950         buffer[sizeof(buffer)-1] = 0;
 951         dev_dbg_f(&udev->dev, "%s\n", buffer);
 952 }
 953 #else
 954 #define print_id(udev) do { } while (0)
 955 #endif
 956
 957 static int eject_installer(struct usb_interface *intf)
 958 {
 959         struct usb_device *udev = interface_to_usbdev(intf);
 960         struct usb_host_interface *iface_desc = &intf->altsetting[0];
 961         struct usb_endpoint_descriptor *endpoint;
 962         unsigned char *cmd;
 963         u8 bulk_out_ep;
 964         int r;
 965
 966         /* Find bulk out endpoint */
 967         endpoint = &iface_desc->endpoint[1].desc;
 968         if ((endpoint->bEndpointAddress & USB_TYPE_MASK) == USB_DIR_OUT &&
 969             (endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
 970             USB_ENDPOINT_XFER_BULK) {
 971                 bulk_out_ep = endpoint->bEndpointAddress;
 972         } else {
 973                 dev_err(&udev->dev,
 974                         "zd1211rw: Could not find bulk out endpoint\n");
 975                 return -ENODEV;
 976         }
 977
 978         cmd = kzalloc(31, GFP_KERNEL);
 979         if (cmd == NULL)
 980                 return -ENODEV;
 981
 982         /* USB bulk command block */
 983         cmd[0] = 0x55;  /* bulk command signature */
 984         cmd[1] = 0x53;  /* bulk command signature */
 985         cmd[2] = 0x42;  /* bulk command signature */
 986         cmd[3] = 0x43;  /* bulk command signature */
 987         cmd[14] = 6;    /* command length */
 988
 989         cmd[15] = 0x1b; /* SCSI command: START STOP UNIT */
 990         cmd[19] = 0x2;  /* eject disc */
 991
 992         dev_info(&udev->dev, "Ejecting virtual installer media...\n");
 993         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, bulk_out_ep),
 994                 cmd, 31, NULL, 2000);
 995         kfree(cmd);
 996         if (r)
 997                 return r;
 998
 999         /* At this point, the device disconnects and reconnects with the real
1000          * ID numbers. */
1001
1002         usb_set_intfdata(intf, NULL);
1003         return 0;
1004 }
1005
1006 static int probe(struct usb_interface *intf, const struct usb_device_id *id)
1007 {
1008         int r;
1009         struct usb_device *udev = interface_to_usbdev(intf);
1010         struct net_device *netdev = NULL;
1011
1012         print_id(udev);
1013
1014         if (id->driver_info & DEVICE_INSTALLER)
1015                 return eject_installer(intf);
1016
1017         switch (udev->speed) {
1018         case USB_SPEED_LOW:
1019         case USB_SPEED_FULL:
1020         case USB_SPEED_HIGH:
1021                 break;
1022         default:
1023                 dev_dbg_f(&intf->dev, "Unknown USB speed\n");
1024                 r = -ENODEV;
1025                 goto error;
1026         }
1027
1028         netdev = zd_netdev_alloc(intf);
1029         if (netdev == NULL) {
1030                 r = -ENOMEM;
1031                 goto error;
1032         }
1033
1034         r = upload_firmware(udev, id->driver_info);
1035         if (r) {
1036                 dev_err(&intf->dev,
1037                        "couldn't load firmware. Error number %d\n", r);
1038                 goto error;
1039         }
1040
1041         r = usb_reset_configuration(udev);
1042         if (r) {
1043                 dev_dbg_f(&intf->dev,
1044                         "couldn't reset configuration. Error number %d\n", r);
1045                 goto error;
1046         }
1047
1048         /* At this point the interrupt endpoint is not generally enabled. We
1049          * save the USB bandwidth until the network device is opened. But
1050          * notify that the initialization of the MAC will require the
1051          * interrupts to be temporary enabled.
1052          */
1053         r = zd_mac_init_hw(zd_netdev_mac(netdev), id->driver_info);
1054         if (r) {
1055                 dev_dbg_f(&intf->dev,
1056                          "couldn't initialize mac. Error number %d\n", r);
1057                 goto error;
1058         }
1059
1060         r = register_netdev(netdev);
1061         if (r) {
1062                 dev_dbg_f(&intf->dev,
1063                          "couldn't register netdev. Error number %d\n", r);
1064                 goto error;
1065         }
1066
1067         dev_dbg_f(&intf->dev, "successful\n");
1068         dev_info(&intf->dev,"%s\n", netdev->name);
1069         return 0;
1070 error:
1071         usb_reset_device(interface_to_usbdev(intf));
1072         zd_netdev_free(netdev);
1073         return r;
1074 }
1075
1076 static void disconnect(struct usb_interface *intf)
1077 {
1078         struct net_device *netdev = zd_intf_to_netdev(intf);
1079         struct zd_mac *mac = zd_netdev_mac(netdev);
1080         struct zd_usb *usb = &mac->chip.usb;
1081
1082         /* Either something really bad happened, or we're just dealing with
1083          * a DEVICE_INSTALLER. */
1084         if (netdev == NULL)
1085                 return;
1086
1087         dev_dbg_f(zd_usb_dev(usb), "\n");
1088
1089         zd_netdev_disconnect(netdev);
1090
1091         /* Just in case something has gone wrong! */
1092         zd_usb_disable_rx(usb);
1093         zd_usb_disable_int(usb);
1094
1095         /* If the disconnect has been caused by a removal of the
1096          * driver module, the reset allows reloading of the driver. If the
1097          * reset will not be executed here, the upload of the firmware in the
1098          * probe function caused by the reloading of the driver will fail.
1099          */
1100         usb_reset_device(interface_to_usbdev(intf));
1101
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 }