git.oblomov.eu Git - linux-2.6/blob - 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@brturbo.com.br>
   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/moduleparam.h>
  28 #include <linux/usb.h>
  29 #include <linux/vmalloc.h>
  30
  31 #include "em28xx.h"
  32
  33 /* #define ENABLE_DEBUG_ISOC_FRAMES */
  34
  35 static unsigned int core_debug = 0;
  36 module_param(core_debug,int,0644);
  37 MODULE_PARM_DESC(core_debug,"enable debug messages [core]");
  38
  39 #define em28xx_coredbg(fmt, arg...) do {\
  40         if (core_debug) \
  41                 printk(KERN_INFO "%s %s :"fmt, \
  42                          dev->name, __FUNCTION__ , ##arg); } while (0)
  43
  44 static unsigned int reg_debug = 0;
  45 module_param(reg_debug,int,0644);
  46 MODULE_PARM_DESC(reg_debug,"enable debug messages [URB reg]");
  47
  48 #define em28xx_regdbg(fmt, arg...) do {\
  49         if (reg_debug) \
  50                 printk(KERN_INFO "%s %s :"fmt, \
  51                          dev->name, __FUNCTION__ , ##arg); } while (0)
  52
  53 static unsigned int isoc_debug = 0;
  54 module_param(isoc_debug,int,0644);
  55 MODULE_PARM_DESC(isoc_debug,"enable debug messages [isoc transfers]");
  56
  57 #define em28xx_isocdbg(fmt, arg...) do {\
  58         if (isoc_debug) \
  59                 printk(KERN_INFO "%s %s :"fmt, \
  60                          dev->name, __FUNCTION__ , ##arg); } while (0)
  61
  62 static int alt = EM28XX_PINOUT;
  63 module_param(alt, int, 0644);
  64 MODULE_PARM_DESC(alt, "alternate setting to use for video endpoint");
  65
  66
  67 /*
  68  * em28xx_request_buffers()
  69  * allocate a number of buffers
  70  */
  71 u32 em28xx_request_buffers(struct em28xx *dev, u32 count)
  72 {
  73         const size_t imagesize = PAGE_ALIGN(dev->frame_size);   /*needs to be page aligned cause the buffers can be mapped individually! */
  74         void *buff = NULL;
  75         u32 i;
  76         em28xx_coredbg("requested %i buffers with size %zi", count, imagesize);
  77         if (count > EM28XX_NUM_FRAMES)
  78                 count = EM28XX_NUM_FRAMES;
  79
  80         dev->num_frames = count;
  81         while (dev->num_frames > 0) {
  82                 if ((buff = vmalloc_32(dev->num_frames * imagesize))) {
  83                         memset(buff, 0, dev->num_frames * imagesize);
  84                         break;
  85                 }
  86                 dev->num_frames--;
  87         }
  88
  89         for (i = 0; i < dev->num_frames; i++) {
  90                 dev->frame[i].bufmem = buff + i * imagesize;
  91                 dev->frame[i].buf.index = i;
  92                 dev->frame[i].buf.m.offset = i * imagesize;
  93                 dev->frame[i].buf.length = dev->frame_size;
  94                 dev->frame[i].buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
  95                 dev->frame[i].buf.sequence = 0;
  96                 dev->frame[i].buf.field = V4L2_FIELD_NONE;
  97                 dev->frame[i].buf.memory = V4L2_MEMORY_MMAP;
  98                 dev->frame[i].buf.flags = 0;
  99         }
 100         return dev->num_frames;
 101 }
 102
 103 /*
 104  * em28xx_queue_unusedframes()
 105  * add all frames that are not currently in use to the inbuffer queue
 106  */
 107 void em28xx_queue_unusedframes(struct em28xx *dev)
 108 {
 109         unsigned long lock_flags;
 110         u32 i;
 111
 112         for (i = 0; i < dev->num_frames; i++)
 113                 if (dev->frame[i].state == F_UNUSED) {
 114                         dev->frame[i].state = F_QUEUED;
 115                         spin_lock_irqsave(&dev->queue_lock, lock_flags);
 116                         list_add_tail(&dev->frame[i].frame, &dev->inqueue);
 117                         spin_unlock_irqrestore(&dev->queue_lock, lock_flags);
 118                 }
 119 }
 120
 121 /*
 122  * em28xx_release_buffers()
 123  * free frame buffers
 124  */
 125 void em28xx_release_buffers(struct em28xx *dev)
 126 {
 127         if (dev->num_frames) {
 128                 vfree(dev->frame[0].bufmem);
 129                 dev->num_frames = 0;
 130         }
 131 }
 132
 133 /*
 134  * em28xx_read_reg_req()
 135  * reads data from the usb device specifying bRequest
 136  */
 137 int em28xx_read_reg_req_len(struct em28xx *dev, u8 req, u16 reg,
 138                                    char *buf, int len)
 139 {
 140         int ret, byte;
 141
 142         if (dev->state & DEV_DISCONNECTED)
 143                 return(-ENODEV);
 144
 145         em28xx_regdbg("req=%02x, reg=%02x ", req, reg);
 146
 147         ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0), req,
 148                               USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 149                               0x0000, reg, buf, len, HZ);
 150
 151         if (reg_debug){
 152                 printk(ret < 0 ? " failed!\n" : "%02x values: ", ret);
 153                 for (byte = 0; byte < len; byte++) {
 154                         printk(" %02x", buf[byte]);
 155                 }
 156                 printk("\n");
 157         }
 158
 159         return ret;
 160 }
 161
 162 /*
 163  * em28xx_read_reg_req()
 164  * reads data from the usb device specifying bRequest
 165  */
 166 int em28xx_read_reg_req(struct em28xx *dev, u8 req, u16 reg)
 167 {
 168         u8 val;
 169         int ret;
 170
 171         if (dev->state & DEV_DISCONNECTED)
 172                 return(-ENODEV);
 173
 174         em28xx_regdbg("req=%02x, reg=%02x:", req, reg);
 175
 176         ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0), req,
 177                               USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 178                               0x0000, reg, &val, 1, HZ);
 179
 180         if (reg_debug)
 181                 printk(ret < 0 ? " failed!\n" : "%02x\n", val);
 182
 183         if (ret < 0)
 184                 return ret;
 185
 186         return val;
 187 }
 188
 189 int em28xx_read_reg(struct em28xx *dev, u16 reg)
 190 {
 191         return em28xx_read_reg_req(dev, USB_REQ_GET_STATUS, reg);
 192 }
 193
 194 /*
 195  * em28xx_write_regs_req()
 196  * sends data to the usb device, specifying bRequest
 197  */
 198 int em28xx_write_regs_req(struct em28xx *dev, u8 req, u16 reg, char *buf,
 199                                  int len)
 200 {
 201         int ret;
 202
 203         /*usb_control_msg seems to expect a kmalloced buffer */
 204         unsigned char *bufs;
 205
 206         if (dev->state & DEV_DISCONNECTED)
 207                 return(-ENODEV);
 208
 209         bufs = kmalloc(len, GFP_KERNEL);
 210
 211         em28xx_regdbg("req=%02x reg=%02x:", req, reg);
 212
 213         if (reg_debug) {
 214                 int i;
 215                 for (i = 0; i < len; ++i)
 216                         printk (" %02x", (unsigned char)buf[i]);
 217                 printk ("\n");
 218         }
 219
 220         if (!bufs)
 221                 return -ENOMEM;
 222         memcpy(bufs, buf, len);
 223         ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), req,
 224                               USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 225                               0x0000, reg, bufs, len, HZ);
 226         msleep(5);              /* FIXME: magic number */
 227         kfree(bufs);
 228         return ret;
 229 }
 230
 231 int em28xx_write_regs(struct em28xx *dev, u16 reg, char *buf, int len)
 232 {
 233         return em28xx_write_regs_req(dev, USB_REQ_GET_STATUS, reg, buf, len);
 234 }
 235
 236 /*
 237  * em28xx_write_reg_bits()
 238  * sets only some bits (specified by bitmask) of a register, by first reading
 239  * the actual value
 240  */
 241 int em28xx_write_reg_bits(struct em28xx *dev, u16 reg, u8 val,
 242                                  u8 bitmask)
 243 {
 244         int oldval;
 245         u8 newval;
 246         if ((oldval = em28xx_read_reg(dev, reg)) < 0)
 247                 return oldval;
 248         newval = (((u8) oldval) & ~bitmask) | (val & bitmask);
 249         return em28xx_write_regs(dev, reg, &newval, 1);
 250 }
 251
 252 /*
 253  * em28xx_write_ac97()
 254  * write a 16 bit value to the specified AC97 address (LSB first!)
 255  */
 256 int em28xx_write_ac97(struct em28xx *dev, u8 reg, u8 * val)
 257 {
 258         int ret;
 259         u8 addr = reg & 0x7f;
 260         if ((ret = em28xx_write_regs(dev, AC97LSB_REG, val, 2)) < 0)
 261                 return ret;
 262         if ((ret = em28xx_write_regs(dev, AC97ADDR_REG, &addr, 1)) < 0)
 263                 return ret;
 264         if ((ret = em28xx_read_reg(dev, AC97BUSY_REG)) < 0)
 265                 return ret;
 266         else if (((u8) ret) & 0x01) {
 267                 em28xx_warn ("AC97 command still being executed: not handled properly!\n");
 268         }
 269         return 0;
 270 }
 271
 272 int em28xx_audio_analog_set(struct em28xx *dev)
 273 {
 274         char s[2] = { 0x00, 0x00 };
 275         s[0] |= 0x1f - dev->volume;
 276         s[1] |= 0x1f - dev->volume;
 277         if (dev->mute)
 278                 s[1] |= 0x80;
 279         return em28xx_write_ac97(dev, MASTER_AC97, s);
 280 }
 281
 282
 283 int em28xx_colorlevels_set_default(struct em28xx *dev)
 284 {
 285         em28xx_write_regs(dev, YGAIN_REG, "\x10", 1);   /* contrast */
 286         em28xx_write_regs(dev, YOFFSET_REG, "\x00", 1); /* brightness */
 287         em28xx_write_regs(dev, UVGAIN_REG, "\x10", 1);  /* saturation */
 288         em28xx_write_regs(dev, UOFFSET_REG, "\x00", 1);
 289         em28xx_write_regs(dev, VOFFSET_REG, "\x00", 1);
 290         em28xx_write_regs(dev, SHARPNESS_REG, "\x00", 1);
 291
 292         em28xx_write_regs(dev, GAMMA_REG, "\x20", 1);
 293         em28xx_write_regs(dev, RGAIN_REG, "\x20", 1);
 294         em28xx_write_regs(dev, GGAIN_REG, "\x20", 1);
 295         em28xx_write_regs(dev, BGAIN_REG, "\x20", 1);
 296         em28xx_write_regs(dev, ROFFSET_REG, "\x00", 1);
 297         em28xx_write_regs(dev, GOFFSET_REG, "\x00", 1);
 298         return em28xx_write_regs(dev, BOFFSET_REG, "\x00", 1);
 299 }
 300
 301 int em28xx_capture_start(struct em28xx *dev, int start)
 302 {
 303         int ret;
 304         /* FIXME: which is the best order? */
 305         /* video registers are sampled by VREF */
 306         if ((ret = em28xx_write_reg_bits(dev, USBSUSP_REG, start ? 0x10 : 0x00,
 307                                           0x10)) < 0)
 308                 return ret;
 309         /* enable video capture */
 310         return em28xx_write_regs(dev, VINENABLE_REG, start ? "\x67" : "\x27", 1);
 311 }
 312
 313 int em28xx_outfmt_set_yuv422(struct em28xx *dev)
 314 {
 315         em28xx_write_regs(dev, OUTFMT_REG, "\x34", 1);
 316         em28xx_write_regs(dev, VINMODE_REG, "\x10", 1);
 317         return em28xx_write_regs(dev, VINCTRL_REG, "\x11", 1);
 318 }
 319
 320 int em28xx_accumulator_set(struct em28xx *dev, u8 xmin, u8 xmax, u8 ymin,
 321                                   u8 ymax)
 322 {
 323         em28xx_coredbg("em28xx Scale: (%d,%d)-(%d,%d)\n", xmin, ymin, xmax, ymax);
 324
 325         em28xx_write_regs(dev, XMIN_REG, &xmin, 1);
 326         em28xx_write_regs(dev, XMAX_REG, &xmax, 1);
 327         em28xx_write_regs(dev, YMIN_REG, &ymin, 1);
 328         return em28xx_write_regs(dev, YMAX_REG, &ymax, 1);
 329 }
 330
 331 int em28xx_capture_area_set(struct em28xx *dev, u8 hstart, u8 vstart,
 332                                    u16 width, u16 height)
 333 {
 334         u8 cwidth = width;
 335         u8 cheight = height;
 336         u8 overflow = (height >> 7 & 0x02) | (width >> 8 & 0x01);
 337
 338         em28xx_coredbg("em28xx Area Set: (%d,%d)\n", (width | (overflow & 2) << 7),
 339                         (height | (overflow & 1) << 8));
 340
 341         em28xx_write_regs(dev, HSTART_REG, &hstart, 1);
 342         em28xx_write_regs(dev, VSTART_REG, &vstart, 1);
 343         em28xx_write_regs(dev, CWIDTH_REG, &cwidth, 1);
 344         em28xx_write_regs(dev, CHEIGHT_REG, &cheight, 1);
 345         return em28xx_write_regs(dev, OFLOW_REG, &overflow, 1);
 346 }
 347
 348 int em28xx_scaler_set(struct em28xx *dev, u16 h, u16 v)
 349 {
 350         u8 mode;
 351         /* the em2800 scaler only supports scaling down to 50% */
 352         if(dev->is_em2800)
 353                 mode = (v ? 0x20 : 0x00) | (h ? 0x10 : 0x00);
 354         else {
 355                 u8 buf[2];
 356                 buf[0] = h;
 357                 buf[1] = h >> 8;
 358                 em28xx_write_regs(dev, HSCALELOW_REG, (char *)buf, 2);
 359                 buf[0] = v;
 360                 buf[1] = v >> 8;
 361                 em28xx_write_regs(dev, VSCALELOW_REG, (char *)buf, 2);
 362                 /* it seems that both H and V scalers must be active to work correctly */
 363                 mode = (h || v)? 0x30: 0x00;
 364         }
 365         return em28xx_write_reg_bits(dev, COMPR_REG, mode, 0x30);
 366 }
 367
 368 /* FIXME: this only function read values from dev */
 369 int em28xx_resolution_set(struct em28xx *dev)
 370 {
 371         int width, height;
 372         width = norm_maxw(dev);
 373         height = norm_maxh(dev) >> 1;
 374
 375         em28xx_outfmt_set_yuv422(dev);
 376         em28xx_accumulator_set(dev, 1, (width - 4) >> 2, 1, (height - 4) >> 2);
 377         em28xx_capture_area_set(dev, 0, 0, width >> 2, height >> 2);
 378         return em28xx_scaler_set(dev, dev->hscale, dev->vscale);
 379 }
 380
 381
 382 /******************* isoc transfer handling ****************************/
 383
 384 #ifdef ENABLE_DEBUG_ISOC_FRAMES
 385 static void em28xx_isoc_dump(struct urb *urb, struct pt_regs *regs)
 386 {
 387         int len = 0;
 388         int ntrans = 0;
 389         int i;
 390
 391         printk(KERN_DEBUG "isocIrq: sf=%d np=%d ec=%x\n",
 392                urb->start_frame, urb->number_of_packets,
 393                urb->error_count);
 394         for (i = 0; i < urb->number_of_packets; i++) {
 395                 unsigned char *buf =
 396                                 urb->transfer_buffer +
 397                                 urb->iso_frame_desc[i].offset;
 398                 int alen = urb->iso_frame_desc[i].actual_length;
 399                 if (alen > 0) {
 400                         if (buf[0] == 0x88) {
 401                                 ntrans++;
 402                                 len += alen;
 403                         } else if (buf[0] == 0x22) {
 404                                 printk(KERN_DEBUG
 405                                                 "= l=%d nt=%d bpp=%d\n",
 406                                 len - 4 * ntrans, ntrans,
 407                                 ntrans == 0 ? 0 : len / ntrans);
 408                                 ntrans = 1;
 409                                 len = alen;
 410                         } else
 411                                 printk(KERN_DEBUG "!\n");
 412                 }
 413                 printk(KERN_DEBUG "   n=%d s=%d al=%d %x\n", i,
 414                        urb->iso_frame_desc[i].status,
 415                        urb->iso_frame_desc[i].actual_length,
 416                        (unsigned int)
 417                                        *((unsigned char *)(urb->transfer_buffer +
 418                                        urb->iso_frame_desc[i].
 419                                        offset)));
 420         }
 421 }
 422 #endif
 423
 424 static inline int em28xx_isoc_video(struct em28xx *dev,struct em28xx_frame_t **f,
 425                                     unsigned long *lock_flags, unsigned char buf)
 426 {
 427         if (!(buf & 0x01)) {
 428                 if ((*f)->state == F_GRABBING) {
 429                         /*previous frame is incomplete */
 430                         if ((*f)->fieldbytesused < dev->field_size) {
 431                                 (*f)->state = F_ERROR;
 432                                 em28xx_isocdbg ("dropping incomplete bottom field (%i missing bytes)",
 433                                          dev->field_size-(*f)->fieldbytesused);
 434                         } else {
 435                                 (*f)->state = F_DONE;
 436                                 (*f)->buf.bytesused = dev->frame_size;
 437                         }
 438                 }
 439                 if ((*f)->state == F_DONE || (*f)->state == F_ERROR) {
 440                         /* move current frame to outqueue and get next free buffer from inqueue */
 441                         spin_lock_irqsave(&dev-> queue_lock, *lock_flags);
 442                         list_move_tail(&(*f)->frame, &dev->outqueue);
 443                         if (!list_empty(&dev->inqueue))
 444                                 (*f) = list_entry(dev-> inqueue.next,
 445                         struct em28xx_frame_t,frame);
 446                         else
 447                                 (*f) = NULL;
 448                         spin_unlock_irqrestore(&dev->queue_lock,*lock_flags);
 449                 }
 450                 if (!(*f)) {
 451                         em28xx_isocdbg ("new frame but no buffer is free");
 452                         return -1;
 453                 }
 454                 do_gettimeofday(&(*f)->buf.timestamp);
 455                 (*f)->buf.sequence = ++dev->frame_count;
 456                 (*f)->buf.field = V4L2_FIELD_INTERLACED;
 457                 (*f)->state = F_GRABBING;
 458                 (*f)->buf.bytesused = 0;
 459                 (*f)->top_field = 1;
 460                 (*f)->fieldbytesused = 0;
 461         } else {
 462                                         /* acquiring bottom field */
 463                 if ((*f)->state == F_GRABBING) {
 464                         if (!(*f)->top_field) {
 465                                 (*f)->state = F_ERROR;
 466                                 em28xx_isocdbg ("unexpected begin of bottom field; discarding it");
 467                         } else if ((*f)-> fieldbytesused < dev->field_size - 172) {
 468                                 (*f)->state = F_ERROR;
 469                                 em28xx_isocdbg ("dropping incomplete top field (%i missing bytes)",
 470                                          dev->field_size-(*f)->fieldbytesused);
 471                         } else {
 472                                 (*f)->top_field = 0;
 473                                 (*f)->fieldbytesused = 0;
 474                         }
 475                 }
 476         }
 477         return (0);
 478 }
 479
 480 static inline void em28xx_isoc_video_copy(struct em28xx *dev,
 481                                           struct em28xx_frame_t **f, unsigned char *buf, int len)
 482 {
 483         void *fieldstart, *startwrite, *startread;
 484         int linesdone, currlinedone, offset, lencopy,remain;
 485
 486         if(dev->frame_size != (*f)->buf.length){
 487                 em28xx_err("frame_size %i and buf.length %i are different!!!\n",dev->frame_size,(*f)->buf.length);
 488                 return;
 489         }
 490
 491         if ((*f)->fieldbytesused + len > dev->field_size)
 492                 len =dev->field_size - (*f)->fieldbytesused;
 493
 494         if (buf[0] != 0x88 && buf[0] != 0x22) {
 495                 em28xx_isocdbg("frame is not complete\n");
 496                 startread = buf;
 497                 len+=4;
 498         } else
 499                 startread = buf + 4;
 500
 501         remain = len;
 502
 503         if ((*f)->top_field)
 504                 fieldstart = (*f)->bufmem;
 505         else
 506                 fieldstart = (*f)->bufmem + dev->bytesperline;
 507
 508         linesdone = (*f)->fieldbytesused / dev->bytesperline;
 509         currlinedone = (*f)->fieldbytesused % dev->bytesperline;
 510         offset = linesdone * dev->bytesperline * 2 + currlinedone;
 511         startwrite = fieldstart + offset;
 512         lencopy = dev->bytesperline - currlinedone;
 513         lencopy = lencopy > remain ? remain : lencopy;
 514
 515         memcpy(startwrite, startread, lencopy);
 516         remain -= lencopy;
 517
 518         while (remain > 0) {
 519                 startwrite += lencopy + dev->bytesperline;
 520                 startread += lencopy;
 521                 if (dev->bytesperline > remain)
 522                         lencopy = remain;
 523                 else
 524                         lencopy = dev->bytesperline;
 525
 526                 memcpy(startwrite, startread, lencopy);
 527                 remain -= lencopy;
 528         }
 529
 530         (*f)->fieldbytesused += len;
 531 }
 532
 533 /*
 534  * em28xx_isoIrq()
 535  * handles the incoming isoc urbs and fills the frames from our inqueue
 536  */
 537 void em28xx_isocIrq(struct urb *urb, struct pt_regs *regs)
 538 {
 539         struct em28xx *dev = urb->context;
 540         int i, status;
 541         struct em28xx_frame_t **f;
 542         unsigned long lock_flags;
 543
 544         if (!dev)
 545                 return;
 546 #ifdef ENABLE_DEBUG_ISOC_FRAMES
 547         if (isoc_debug>1)
 548                 em28xx_isoc_dump(urb, regs);
 549 #endif
 550
 551         if (urb->status == -ENOENT)
 552                 return;
 553
 554         f = &dev->frame_current;
 555
 556         if (dev->stream == STREAM_INTERRUPT) {
 557                 dev->stream = STREAM_OFF;
 558                 if ((*f))
 559                         (*f)->state = F_QUEUED;
 560                 em28xx_isocdbg("stream interrupted");
 561                 wake_up_interruptible(&dev->wait_stream);
 562         }
 563
 564         if ((dev->state & DEV_DISCONNECTED) || (dev->state & DEV_MISCONFIGURED))
 565                 return;
 566
 567         if (dev->stream == STREAM_ON && !list_empty(&dev->inqueue)) {
 568                 if (!(*f))
 569                         (*f) = list_entry(dev->inqueue.next,
 570                 struct em28xx_frame_t, frame);
 571
 572                 for (i = 0; i < urb->number_of_packets; i++) {
 573                         unsigned char *buf = urb->transfer_buffer +
 574                                         urb->iso_frame_desc[i].offset;
 575                         int len = urb->iso_frame_desc[i].actual_length - 4;
 576
 577                         if (urb->iso_frame_desc[i].status) {
 578                                 em28xx_isocdbg("data error: [%d] len=%d, status=%d", i,
 579                                         urb->iso_frame_desc[i].actual_length,
 580                                         urb->iso_frame_desc[i].status);
 581                                 if (urb->iso_frame_desc[i].status != -EPROTO)
 582                                         continue;
 583                         }
 584                         if (urb->iso_frame_desc[i].actual_length <= 0) {
 585                                 em28xx_isocdbg("packet %d is empty",i);
 586                                 continue;
 587                         }
 588                         if (urb->iso_frame_desc[i].actual_length >
 589                                                  dev->max_pkt_size) {
 590                                 em28xx_isocdbg("packet bigger than packet size");
 591                                 continue;
 592                         }
 593                         /*new frame */
 594                         if (buf[0] == 0x22 && buf[1] == 0x5a) {
 595                                 em28xx_isocdbg("Video frame, length=%i!",len);
 596
 597                                 if (em28xx_isoc_video(dev,f,&lock_flags,buf[2]))
 598                                 break;
 599                         } else if (buf[0]==0x33 && buf[1]==0x95 && buf[2]==0x00) {
 600                                 em28xx_isocdbg("VBI HEADER!!!");
 601                         }
 602
 603                         /* actual copying */
 604                         if ((*f)->state == F_GRABBING) {
 605                                 em28xx_isoc_video_copy(dev,f,buf, len);
 606                         }
 607                 }
 608         }
 609
 610         for (i = 0; i < urb->number_of_packets; i++) {
 611                 urb->iso_frame_desc[i].status = 0;
 612                 urb->iso_frame_desc[i].actual_length = 0;
 613         }
 614
 615         urb->status = 0;
 616         if ((status = usb_submit_urb(urb, GFP_ATOMIC))) {
 617                 em28xx_errdev("resubmit of urb failed (error=%i)\n", status);
 618                 dev->state |= DEV_MISCONFIGURED;
 619         }
 620         wake_up_interruptible(&dev->wait_frame);
 621         return;
 622 }
 623
 624 /*
 625  * em28xx_uninit_isoc()
 626  * deallocates the buffers and urbs allocated during em28xx_init_iosc()
 627  */
 628 void em28xx_uninit_isoc(struct em28xx *dev)
 629 {
 630         int i;
 631
 632         for (i = 0; i < EM28XX_NUM_BUFS; i++) {
 633                 if (dev->urb[i]) {
 634                         usb_kill_urb(dev->urb[i]);
 635                         if (dev->transfer_buffer[i]){
 636                                 usb_buffer_free(dev->udev,(EM28XX_NUM_PACKETS*dev->max_pkt_size),dev->transfer_buffer[i],dev->urb[i]->transfer_dma);
 637                         }
 638                         usb_free_urb(dev->urb[i]);
 639                 }
 640                 dev->urb[i] = NULL;
 641                 dev->transfer_buffer[i] = NULL;
 642         }
 643         em28xx_capture_start(dev, 0);
 644 }
 645
 646 /*
 647  * em28xx_init_isoc()
 648  * allocates transfer buffers and submits the urbs for isoc transfer
 649  */
 650 int em28xx_init_isoc(struct em28xx *dev)
 651 {
 652         /* change interface to 3 which allowes the biggest packet sizes */
 653         int i, errCode;
 654         const int sb_size = EM28XX_NUM_PACKETS * dev->max_pkt_size;
 655
 656         /* reset streaming vars */
 657         dev->frame_current = NULL;
 658         dev->frame_count = 0;
 659
 660         /* allocate urbs */
 661         for (i = 0; i < EM28XX_NUM_BUFS; i++) {
 662                 struct urb *urb;
 663                 int j, k;
 664                 /* allocate transfer buffer */
 665                 urb = usb_alloc_urb(EM28XX_NUM_PACKETS, GFP_KERNEL);
 666                 if (!urb){
 667                         em28xx_errdev("cannot alloc urb %i\n", i);
 668                         em28xx_uninit_isoc(dev);
 669                         return -ENOMEM;
 670                 }
 671                 dev->transfer_buffer[i] = usb_buffer_alloc(dev->udev, sb_size, GFP_KERNEL,&urb->transfer_dma);
 672                 if (!dev->transfer_buffer[i]) {
 673                         em28xx_errdev
 674                                         ("unable to allocate %i bytes for transfer buffer %i\n",
 675                                          sb_size, i);
 676                         em28xx_uninit_isoc(dev);
 677                         return -ENOMEM;
 678                 }
 679                 memset(dev->transfer_buffer[i], 0, sb_size);
 680                 urb->dev = dev->udev;
 681                 urb->context = dev;
 682                 urb->pipe = usb_rcvisocpipe(dev->udev, 0x82);
 683                 urb->transfer_flags = URB_ISO_ASAP;
 684                 urb->interval = 1;
 685                 urb->transfer_buffer = dev->transfer_buffer[i];
 686                 urb->complete = em28xx_isocIrq;
 687                 urb->number_of_packets = EM28XX_NUM_PACKETS;
 688                 urb->transfer_buffer_length = sb_size;
 689                 for (j = k = 0; j < EM28XX_NUM_PACKETS;
 690                                 j++, k += dev->max_pkt_size) {
 691                         urb->iso_frame_desc[j].offset = k;
 692                         urb->iso_frame_desc[j].length =
 693                                 dev->max_pkt_size;
 694                 }
 695                 dev->urb[i] = urb;
 696         }
 697
 698         /* submit urbs */
 699         for (i = 0; i < EM28XX_NUM_BUFS; i++) {
 700                 errCode = usb_submit_urb(dev->urb[i], GFP_KERNEL);
 701                 if (errCode) {
 702                         em28xx_errdev("submit of urb %i failed (error=%i)\n", i,
 703                                       errCode);
 704                         em28xx_uninit_isoc(dev);
 705                         return errCode;
 706                 }
 707         }
 708
 709         return 0;
 710 }
 711
 712 int em28xx_set_alternate(struct em28xx *dev)
 713 {
 714         int errCode, prev_alt = dev->alt;
 715         dev->alt = alt;
 716         if (dev->alt == 0) {
 717                 int i;
 718                 for(i=0;i< dev->num_alt; i++)
 719                         if(dev->alt_max_pkt_size[i]>dev->alt_max_pkt_size[dev->alt])
 720                                 dev->alt=i;
 721         }
 722
 723         if (dev->alt != prev_alt) {
 724                 dev->max_pkt_size = dev->alt_max_pkt_size[dev->alt];
 725                 em28xx_coredbg("setting alternate %d with wMaxPacketSize=%u\n", dev->alt,
 726                        dev->max_pkt_size);
 727                 errCode = usb_set_interface(dev->udev, 0, dev->alt);
 728                 if (errCode < 0) {
 729                         em28xx_errdev ("cannot change alternate number to %d (error=%i)\n",
 730                                                         dev->alt, errCode);
 731                         return errCode;
 732                 }
 733         }
 734         return 0;
 735 }