drivers/media/video/em28xx/em28xx-core.c

   1 /*
   2    em28xx-core.c - driver for Empia EM2800/EM2820/2840 USB video capture devices
   3
   4    Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
   5                       Markus Rechberger <mrechberger@gmail.com>
   6                       Mauro Carvalho Chehab <mchehab@infradead.org>
   7                       Sascha Sommer <saschasommer@freenet.de>
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 #include <linux/init.h>
  25 #include <linux/list.h>
  26 #include <linux/module.h>
  27 #include <linux/usb.h>
  28 #include <linux/vmalloc.h>
  29
  30 #include "em28xx.h"
  31
  32 /* #define ENABLE_DEBUG_ISOC_FRAMES */
  33
  34 static unsigned int core_debug;
  35 module_param(core_debug,int,0644);
  36 MODULE_PARM_DESC(core_debug,"enable debug messages [core]");
  37
  38 #define em28xx_coredbg(fmt, arg...) do {\
  39         if (core_debug) \
  40                 printk(KERN_INFO "%s %s :"fmt, \
  41                          dev->name, __func__ , ##arg); } while (0)
  42
  43 static unsigned int reg_debug;
  44 module_param(reg_debug,int,0644);
  45 MODULE_PARM_DESC(reg_debug,"enable debug messages [URB reg]");
  46
  47 #define em28xx_regdbg(fmt, arg...) do {\
  48         if (reg_debug) \
  49                 printk(KERN_INFO "%s %s :"fmt, \
  50                          dev->name, __func__ , ##arg); } while (0)
  51
  52 static int alt = EM28XX_PINOUT;
  53 module_param(alt, int, 0644);
  54 MODULE_PARM_DESC(alt, "alternate setting to use for video endpoint");
  55
  56 /* FIXME */
  57 #define em28xx_isocdbg(fmt, arg...) do {\
  58         if (core_debug) \
  59                 printk(KERN_INFO "%s %s :"fmt, \
  60                          dev->name, __func__ , ##arg); } while (0)
  61
  62 /*
  63  * em28xx_read_reg_req()
  64  * reads data from the usb device specifying bRequest
  65  */
  66 int em28xx_read_reg_req_len(struct em28xx *dev, u8 req, u16 reg,
  67                                    char *buf, int len)
  68 {
  69         int ret, byte;
  70
  71         if (dev->state & DEV_DISCONNECTED)
  72                 return(-ENODEV);
  73
  74         em28xx_regdbg("req=%02x, reg=%02x ", req, reg);
  75
  76         ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0), req,
  77                               USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
  78                               0x0000, reg, buf, len, HZ);
  79
  80         if (reg_debug) {
  81                 printk(ret < 0 ? " failed!\n" : "%02x values: ", ret);
  82                 for (byte = 0; byte < len; byte++)
  83                         printk(KERN_INFO " %02x", (unsigned char)buf[byte]);
  84
  85                 printk(KERN_INFO "\n");
  86         }
  87
  88         return ret;
  89 }
  90
  91 /*
  92  * em28xx_read_reg_req()
  93  * reads data from the usb device specifying bRequest
  94  */
  95 int em28xx_read_reg_req(struct em28xx *dev, u8 req, u16 reg)
  96 {
  97         u8 val;
  98         int ret;
  99
 100         if (dev->state & DEV_DISCONNECTED)
 101                 return(-ENODEV);
 102
 103         em28xx_regdbg("req=%02x, reg=%02x:", req, reg);
 104
 105         ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0), req,
 106                               USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 107                               0x0000, reg, &val, 1, HZ);
 108
 109         if (reg_debug)
 110                 printk(ret < 0 ? " failed!\n" :
 111                                  "%02x\n", (unsigned char) val);
 112
 113         if (ret < 0)
 114                 return ret;
 115
 116         return val;
 117 }
 118
 119 int em28xx_read_reg(struct em28xx *dev, u16 reg)
 120 {
 121         return em28xx_read_reg_req(dev, USB_REQ_GET_STATUS, reg);
 122 }
 123
 124 /*
 125  * em28xx_write_regs_req()
 126  * sends data to the usb device, specifying bRequest
 127  */
 128 int em28xx_write_regs_req(struct em28xx *dev, u8 req, u16 reg, char *buf,
 129                                  int len)
 130 {
 131         int ret;
 132
 133         /*usb_control_msg seems to expect a kmalloced buffer */
 134         unsigned char *bufs;
 135
 136         if (dev->state & DEV_DISCONNECTED)
 137                 return(-ENODEV);
 138
 139         bufs = kmalloc(len, GFP_KERNEL);
 140
 141         em28xx_regdbg("req=%02x reg=%02x:", req, reg);
 142
 143         if (reg_debug) {
 144                 int i;
 145                 for (i = 0; i < len; ++i)
 146                         printk(KERN_INFO " %02x", (unsigned char)buf[i]);
 147                 printk(KERN_INFO "\n");
 148         }
 149
 150         if (!bufs)
 151                 return -ENOMEM;
 152         memcpy(bufs, buf, len);
 153         ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), req,
 154                               USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 155                               0x0000, reg, bufs, len, HZ);
 156         if (dev->wait_after_write)
 157                 msleep(dev->wait_after_write);
 158
 159         kfree(bufs);
 160         return ret;
 161 }
 162
 163 int em28xx_write_regs(struct em28xx *dev, u16 reg, char *buf, int len)
 164 {
 165         return em28xx_write_regs_req(dev, USB_REQ_GET_STATUS, reg, buf, len);
 166 }
 167
 168 /*
 169  * em28xx_write_reg_bits()
 170  * sets only some bits (specified by bitmask) of a register, by first reading
 171  * the actual value
 172  */
 173 static int em28xx_write_reg_bits(struct em28xx *dev, u16 reg, u8 val,
 174                                  u8 bitmask)
 175 {
 176         int oldval;
 177         u8 newval;
 178
 179         oldval = em28xx_read_reg(dev, reg);
 180
 181         if (oldval < 0)
 182                 return oldval;
 183
 184         newval = (((u8) oldval) & ~bitmask) | (val & bitmask);
 185         return em28xx_write_regs(dev, reg, &newval, 1);
 186 }
 187
 188 /*
 189  * em28xx_write_ac97()
 190  * write a 16 bit value to the specified AC97 address (LSB first!)
 191  */
 192 static int em28xx_write_ac97(struct em28xx *dev, u8 reg, u8 *val)
 193 {
 194         int ret, i;
 195         u8 addr = reg & 0x7f;
 196
 197         ret = em28xx_write_regs(dev, EM28XX_R40_AC97LSB, val, 2);
 198         if (ret < 0)
 199                 return ret;
 200
 201         ret = em28xx_write_regs(dev, EM28XX_R42_AC97ADDR, &addr, 1);
 202         if (ret < 0)
 203                 return ret;
 204
 205         /* Wait up to 50 ms for AC97 command to complete */
 206         for (i = 0; i < 10; i++) {
 207                 ret = em28xx_read_reg(dev, EM28XX_R43_AC97BUSY);
 208                 if (ret < 0)
 209                         return ret;
 210
 211                 if (!(ret & 0x01))
 212                         return 0;
 213                 msleep(5);
 214         }
 215         em28xx_warn("AC97 command still being executed: not handled properly!\n");
 216         return 0;
 217 }
 218
 219 static int em28xx_set_audio_source(struct em28xx *dev)
 220 {
 221         static char *enable  = "\x08\x08";
 222         static char *disable = "\x08\x88";
 223         char *video = enable, *line = disable;
 224         int ret;
 225         u8 input;
 226
 227         if (dev->is_em2800) {
 228                 if (dev->ctl_ainput)
 229                         input = EM2800_AUDIO_SRC_LINE;
 230                 else
 231                         input = EM2800_AUDIO_SRC_TUNER;
 232
 233                 ret = em28xx_write_regs(dev, EM2800_R08_AUDIOSRC, &input, 1);
 234                 if (ret < 0)
 235                         return ret;
 236         }
 237
 238         if (dev->has_msp34xx)
 239                 input = EM28XX_AUDIO_SRC_TUNER;
 240         else {
 241                 switch (dev->ctl_ainput) {
 242                 case EM28XX_AMUX_VIDEO:
 243                         input = EM28XX_AUDIO_SRC_TUNER;
 244                         break;
 245                 case EM28XX_AMUX_LINE_IN:
 246                         input = EM28XX_AUDIO_SRC_LINE;
 247                         break;
 248                 case EM28XX_AMUX_AC97_VIDEO:
 249                         input = EM28XX_AUDIO_SRC_LINE;
 250                         break;
 251                 case EM28XX_AMUX_AC97_LINE_IN:
 252                         input = EM28XX_AUDIO_SRC_LINE;
 253                         video = disable;
 254                         line  = enable;
 255                         break;
 256                 }
 257         }
 258
 259         ret = em28xx_write_reg_bits(dev, EM28XX_R0E_AUDIOSRC, input, 0xc0);
 260         if (ret < 0)
 261                 return ret;
 262         msleep(5);
 263
 264         /* Sets AC97 mixer registers
 265            This is seems to be needed, even for non-ac97 configs
 266          */
 267         ret = em28xx_write_ac97(dev, EM28XX_R14_VIDEO_AC97, video);
 268         if (ret < 0)
 269                 return ret;
 270
 271         ret = em28xx_write_ac97(dev, EM28XX_R10_LINE_IN_AC97, line);
 272
 273         return ret;
 274 }
 275
 276 int em28xx_audio_analog_set(struct em28xx *dev)
 277 {
 278         int ret;
 279         char s[2] = { 0x00, 0x00 };
 280         u8 xclk = 0x07;
 281
 282         s[0] |= 0x1f - dev->volume;
 283         s[1] |= 0x1f - dev->volume;
 284
 285         /* Mute */
 286         s[1] |= 0x80;
 287         ret = em28xx_write_ac97(dev, EM28XX_R02_MASTER_AC97, s);
 288
 289         if (ret < 0)
 290                 return ret;
 291
 292         if (dev->has_12mhz_i2s)
 293                 xclk |= 0x20;
 294
 295         if (!dev->mute)
 296                 xclk |= 0x80;
 297
 298         ret = em28xx_write_reg_bits(dev, EM28XX_R0F_XCLK, xclk, 0xa7);
 299         if (ret < 0)
 300                 return ret;
 301         msleep(10);
 302
 303         /* Selects the proper audio input */
 304         ret = em28xx_set_audio_source(dev);
 305
 306         /* Unmute device */
 307         if (!dev->mute)
 308                 s[1] &= ~0x80;
 309         ret = em28xx_write_ac97(dev, EM28XX_R02_MASTER_AC97, s);
 310
 311         return ret;
 312 }
 313 EXPORT_SYMBOL_GPL(em28xx_audio_analog_set);
 314
 315 int em28xx_colorlevels_set_default(struct em28xx *dev)
 316 {
 317         em28xx_write_regs(dev, EM28XX_R20_YGAIN, "\x10", 1);    /* contrast */
 318         em28xx_write_regs(dev, EM28XX_R21_YOFFSET, "\x00", 1);  /* brightness */
 319         em28xx_write_regs(dev, EM28XX_R22_UVGAIN, "\x10", 1);   /* saturation */
 320         em28xx_write_regs(dev, EM28XX_R23_UOFFSET, "\x00", 1);
 321         em28xx_write_regs(dev, EM28XX_R24_VOFFSET, "\x00", 1);
 322         em28xx_write_regs(dev, EM28XX_R25_SHARPNESS, "\x00", 1);
 323
 324         em28xx_write_regs(dev, EM28XX_R14_GAMMA, "\x20", 1);
 325         em28xx_write_regs(dev, EM28XX_R15_RGAIN, "\x20", 1);
 326         em28xx_write_regs(dev, EM28XX_R16_GGAIN, "\x20", 1);
 327         em28xx_write_regs(dev, EM28XX_R17_BGAIN, "\x20", 1);
 328         em28xx_write_regs(dev, EM28XX_R18_ROFFSET, "\x00", 1);
 329         em28xx_write_regs(dev, EM28XX_R19_GOFFSET, "\x00", 1);
 330         return em28xx_write_regs(dev, EM28XX_R1A_BOFFSET, "\x00", 1);
 331 }
 332
 333 int em28xx_capture_start(struct em28xx *dev, int start)
 334 {
 335         int rc;
 336         /* FIXME: which is the best order? */
 337         /* video registers are sampled by VREF */
 338         rc = em28xx_write_reg_bits(dev, EM28XX_R0C_USBSUSP,
 339                                    start ? 0x10 : 0x00, 0x10);
 340         if (rc < 0)
 341                 return rc;
 342
 343         if (!start) {
 344                 /* disable video capture */
 345                 rc = em28xx_write_regs(dev, EM28XX_R12_VINENABLE, "\x27", 1);
 346                 return rc;
 347         }
 348
 349         /* enable video capture */
 350         rc = em28xx_write_regs_req(dev, 0x00, 0x48, "\x00", 1);
 351
 352         if (dev->mode == EM28XX_ANALOG_MODE)
 353                 rc = em28xx_write_regs(dev, EM28XX_R12_VINENABLE, "\x67", 1);
 354         else
 355                 rc = em28xx_write_regs(dev, EM28XX_R12_VINENABLE, "\x37", 1);
 356
 357         msleep(6);
 358
 359         return rc;
 360 }
 361
 362 int em28xx_outfmt_set_yuv422(struct em28xx *dev)
 363 {
 364         em28xx_write_regs(dev, EM28XX_R27_OUTFMT, "\x34", 1);
 365         em28xx_write_regs(dev, EM28XX_R10_VINMODE, "\x10", 1);
 366         return em28xx_write_regs(dev, EM28XX_R11_VINCTRL, "\x11", 1);
 367 }
 368
 369 static int em28xx_accumulator_set(struct em28xx *dev, u8 xmin, u8 xmax,
 370                                   u8 ymin, u8 ymax)
 371 {
 372         em28xx_coredbg("em28xx Scale: (%d,%d)-(%d,%d)\n",
 373                         xmin, ymin, xmax, ymax);
 374
 375         em28xx_write_regs(dev, EM28XX_R28_XMIN, &xmin, 1);
 376         em28xx_write_regs(dev, EM28XX_R29_XMAX, &xmax, 1);
 377         em28xx_write_regs(dev, EM28XX_R2A_YMIN, &ymin, 1);
 378         return em28xx_write_regs(dev, EM28XX_R2B_YMAX, &ymax, 1);
 379 }
 380
 381 static int em28xx_capture_area_set(struct em28xx *dev, u8 hstart, u8 vstart,
 382                                    u16 width, u16 height)
 383 {
 384         u8 cwidth = width;
 385         u8 cheight = height;
 386         u8 overflow = (height >> 7 & 0x02) | (width >> 8 & 0x01);
 387
 388         em28xx_coredbg("em28xx Area Set: (%d,%d)\n",
 389                         (width | (overflow & 2) << 7),
 390                         (height | (overflow & 1) << 8));
 391
 392         em28xx_write_regs(dev, EM28XX_R1C_HSTART, &hstart, 1);
 393         em28xx_write_regs(dev, EM28XX_R1D_VSTART, &vstart, 1);
 394         em28xx_write_regs(dev, EM28XX_R1E_CWIDTH, &cwidth, 1);
 395         em28xx_write_regs(dev, EM28XX_R1F_CHEIGHT, &cheight, 1);
 396         return em28xx_write_regs(dev, EM28XX_R1B_OFLOW, &overflow, 1);
 397 }
 398
 399 static int em28xx_scaler_set(struct em28xx *dev, u16 h, u16 v)
 400 {
 401         u8 mode;
 402         /* the em2800 scaler only supports scaling down to 50% */
 403         if (dev->is_em2800)
 404                 mode = (v ? 0x20 : 0x00) | (h ? 0x10 : 0x00);
 405         else {
 406                 u8 buf[2];
 407                 buf[0] = h;
 408                 buf[1] = h >> 8;
 409                 em28xx_write_regs(dev, EM28XX_R30_HSCALELOW, (char *)buf, 2);
 410                 buf[0] = v;
 411                 buf[1] = v >> 8;
 412                 em28xx_write_regs(dev, EM28XX_R32_VSCALELOW, (char *)buf, 2);
 413                 /* it seems that both H and V scalers must be active
 414                    to work correctly */
 415                 mode = (h || v)? 0x30: 0x00;
 416         }
 417         return em28xx_write_reg_bits(dev, EM28XX_R26_COMPR, mode, 0x30);
 418 }
 419
 420 /* FIXME: this only function read values from dev */
 421 int em28xx_resolution_set(struct em28xx *dev)
 422 {
 423         int width, height;
 424         width = norm_maxw(dev);
 425         height = norm_maxh(dev) >> 1;
 426
 427         em28xx_outfmt_set_yuv422(dev);
 428         em28xx_accumulator_set(dev, 1, (width - 4) >> 2, 1, (height - 4) >> 2);
 429         em28xx_capture_area_set(dev, 0, 0, width >> 2, height >> 2);
 430         return em28xx_scaler_set(dev, dev->hscale, dev->vscale);
 431 }
 432
 433 int em28xx_set_alternate(struct em28xx *dev)
 434 {
 435         int errCode, prev_alt = dev->alt;
 436         int i;
 437         unsigned int min_pkt_size = dev->width * 2 + 4;
 438
 439         /* When image size is bigger than a certain value,
 440            the frame size should be increased, otherwise, only
 441            green screen will be received.
 442          */
 443         if (dev->width * 2 * dev->height > 720 * 240 * 2)
 444                 min_pkt_size *= 2;
 445
 446         for (i = 0; i < dev->num_alt; i++) {
 447                 /* stop when the selected alt setting offers enough bandwidth */
 448                 if (dev->alt_max_pkt_size[i] >= min_pkt_size) {
 449                         dev->alt = i;
 450                         break;
 451                 /* otherwise make sure that we end up with the maximum bandwidth
 452                    because the min_pkt_size equation might be wrong...
 453                 */
 454                 } else if (dev->alt_max_pkt_size[i] >
 455                            dev->alt_max_pkt_size[dev->alt])
 456                         dev->alt = i;
 457         }
 458
 459         if (dev->alt != prev_alt) {
 460                 em28xx_coredbg("minimum isoc packet size: %u (alt=%d)\n",
 461                                 min_pkt_size, dev->alt);
 462                 dev->max_pkt_size = dev->alt_max_pkt_size[dev->alt];
 463                 em28xx_coredbg("setting alternate %d with wMaxPacketSize=%u\n",
 464                                dev->alt, dev->max_pkt_size);
 465                 errCode = usb_set_interface(dev->udev, 0, dev->alt);
 466                 if (errCode < 0) {
 467                         em28xx_errdev("cannot change alternate number to %d (error=%i)\n",
 468                                         dev->alt, errCode);
 469                         return errCode;
 470                 }
 471         }
 472         return 0;
 473 }
 474
 475 /* ------------------------------------------------------------------
 476         URB control
 477    ------------------------------------------------------------------*/
 478
 479 /*
 480  * IRQ callback, called by URB callback
 481  */
 482 static void em28xx_irq_callback(struct urb *urb)
 483 {
 484         struct em28xx_dmaqueue  *dma_q = urb->context;
 485         struct em28xx *dev = container_of(dma_q, struct em28xx, vidq);
 486         int rc, i;
 487
 488         /* Copy data from URB */
 489         spin_lock(&dev->slock);
 490         rc = dev->isoc_ctl.isoc_copy(dev, urb);
 491         spin_unlock(&dev->slock);
 492
 493         /* Reset urb buffers */
 494         for (i = 0; i < urb->number_of_packets; i++) {
 495                 urb->iso_frame_desc[i].status = 0;
 496                 urb->iso_frame_desc[i].actual_length = 0;
 497         }
 498         urb->status = 0;
 499
 500         urb->status = usb_submit_urb(urb, GFP_ATOMIC);
 501         if (urb->status) {
 502                 em28xx_err("urb resubmit failed (error=%i)\n",
 503                         urb->status);
 504         }
 505 }
 506
 507 /*
 508  * Stop and Deallocate URBs
 509  */
 510 void em28xx_uninit_isoc(struct em28xx *dev)
 511 {
 512         struct urb *urb;
 513         int i;
 514
 515         em28xx_isocdbg("em28xx: called em28xx_uninit_isoc\n");
 516
 517         dev->isoc_ctl.nfields = -1;
 518         for (i = 0; i < dev->isoc_ctl.num_bufs; i++) {
 519                 urb = dev->isoc_ctl.urb[i];
 520                 if (urb) {
 521                         usb_kill_urb(urb);
 522                         usb_unlink_urb(urb);
 523                         if (dev->isoc_ctl.transfer_buffer[i]) {
 524                                 usb_buffer_free(dev->udev,
 525                                         urb->transfer_buffer_length,
 526                                         dev->isoc_ctl.transfer_buffer[i],
 527                                         urb->transfer_dma);
 528                         }
 529                         usb_free_urb(urb);
 530                         dev->isoc_ctl.urb[i] = NULL;
 531                 }
 532                 dev->isoc_ctl.transfer_buffer[i] = NULL;
 533         }
 534
 535         kfree(dev->isoc_ctl.urb);
 536         kfree(dev->isoc_ctl.transfer_buffer);
 537
 538         dev->isoc_ctl.urb = NULL;
 539         dev->isoc_ctl.transfer_buffer = NULL;
 540         dev->isoc_ctl.num_bufs = 0;
 541
 542         em28xx_capture_start(dev, 0);
 543 }
 544 EXPORT_SYMBOL_GPL(em28xx_uninit_isoc);
 545
 546 /*
 547  * Allocate URBs and start IRQ
 548  */
 549 int em28xx_init_isoc(struct em28xx *dev, int max_packets,
 550                      int num_bufs, int max_pkt_size,
 551                      int (*isoc_copy) (struct em28xx *dev, struct urb *urb),
 552                      int cap_type)
 553 {
 554         struct em28xx_dmaqueue *dma_q = &dev->vidq;
 555         int i;
 556         int sb_size, pipe;
 557         struct urb *urb;
 558         int j, k;
 559         int rc;
 560
 561         em28xx_isocdbg("em28xx: called em28xx_prepare_isoc\n");
 562
 563         /* De-allocates all pending stuff */
 564         em28xx_uninit_isoc(dev);
 565
 566         dev->isoc_ctl.isoc_copy = isoc_copy;
 567         dev->isoc_ctl.num_bufs = num_bufs;
 568
 569         dev->isoc_ctl.urb = kzalloc(sizeof(void *)*num_bufs,  GFP_KERNEL);
 570         if (!dev->isoc_ctl.urb) {
 571                 em28xx_errdev("cannot alloc memory for usb buffers\n");
 572                 return -ENOMEM;
 573         }
 574
 575         dev->isoc_ctl.transfer_buffer = kzalloc(sizeof(void *)*num_bufs,
 576                                               GFP_KERNEL);
 577         if (!dev->isoc_ctl.urb) {
 578                 em28xx_errdev("cannot allocate memory for usbtransfer\n");
 579                 kfree(dev->isoc_ctl.urb);
 580                 return -ENOMEM;
 581         }
 582
 583         dev->isoc_ctl.max_pkt_size = max_pkt_size;
 584         dev->isoc_ctl.buf = NULL;
 585
 586         sb_size = max_packets * dev->isoc_ctl.max_pkt_size;
 587
 588         /* allocate urbs and transfer buffers */
 589         for (i = 0; i < dev->isoc_ctl.num_bufs; i++) {
 590                 urb = usb_alloc_urb(max_packets, GFP_KERNEL);
 591                 if (!urb) {
 592                         em28xx_err("cannot alloc isoc_ctl.urb %i\n", i);
 593                         em28xx_uninit_isoc(dev);
 594                         return -ENOMEM;
 595                 }
 596                 dev->isoc_ctl.urb[i] = urb;
 597
 598                 dev->isoc_ctl.transfer_buffer[i] = usb_buffer_alloc(dev->udev,
 599                         sb_size, GFP_KERNEL, &urb->transfer_dma);
 600                 if (!dev->isoc_ctl.transfer_buffer[i]) {
 601                         em28xx_err("unable to allocate %i bytes for transfer"
 602                                         " buffer %i%s\n",
 603                                         sb_size, i,
 604                                         in_interrupt()?" while in int":"");
 605                         em28xx_uninit_isoc(dev);
 606                         return -ENOMEM;
 607                 }
 608                 memset(dev->isoc_ctl.transfer_buffer[i], 0, sb_size);
 609
 610                 /* FIXME: this is a hack - should be
 611                         'desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK'
 612                         should also be using 'desc.bInterval'
 613                  */
 614                 pipe = usb_rcvisocpipe(dev->udev,
 615                         cap_type == EM28XX_ANALOG_CAPTURE ? 0x82 : 0x84);
 616
 617                 usb_fill_int_urb(urb, dev->udev, pipe,
 618                                  dev->isoc_ctl.transfer_buffer[i], sb_size,
 619                                  em28xx_irq_callback, dma_q, 1);
 620
 621                 urb->number_of_packets = max_packets;
 622                 urb->transfer_flags = URB_ISO_ASAP;
 623
 624                 k = 0;
 625                 for (j = 0; j < max_packets; j++) {
 626                         urb->iso_frame_desc[j].offset = k;
 627                         urb->iso_frame_desc[j].length =
 628                                                 dev->isoc_ctl.max_pkt_size;
 629                         k += dev->isoc_ctl.max_pkt_size;
 630                 }
 631         }
 632
 633         init_waitqueue_head(&dma_q->wq);
 634
 635         em28xx_capture_start(dev, cap_type);
 636
 637         /* submit urbs and enables IRQ */
 638         for (i = 0; i < dev->isoc_ctl.num_bufs; i++) {
 639                 rc = usb_submit_urb(dev->isoc_ctl.urb[i], GFP_ATOMIC);
 640                 if (rc) {
 641                         em28xx_err("submit of urb %i failed (error=%i)\n", i,
 642                                    rc);
 643                         em28xx_uninit_isoc(dev);
 644                         return rc;
 645                 }
 646         }
 647
 648         return 0;
 649 }
 650 EXPORT_SYMBOL_GPL(em28xx_init_isoc);