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, __FUNCTION__ , ##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, __FUNCTION__ , ##arg); } while (0)
  51
  52 static unsigned int isoc_debug;
  53 module_param(isoc_debug,int,0644);
  54 MODULE_PARM_DESC(isoc_debug,"enable debug messages [isoc transfers]");
  55
  56 #define em28xx_isocdbg(fmt, arg...) do {\
  57         if (isoc_debug) \
  58                 printk(KERN_INFO "%s %s :"fmt, \
  59                          dev->name, __FUNCTION__ , ##arg); } while (0)
  60
  61 static int alt = EM28XX_PINOUT;
  62 module_param(alt, int, 0644);
  63 MODULE_PARM_DESC(alt, "alternate setting to use for video endpoint");
  64
  65
  66 /*
  67  * em28xx_request_buffers()
  68  * allocate a number of buffers
  69  */
  70 u32 em28xx_request_buffers(struct em28xx *dev, u32 count)
  71 {
  72         const size_t imagesize = PAGE_ALIGN(dev->frame_size);   /*needs to be page aligned cause the buffers can be mapped individually! */
  73         void *buff = NULL;
  74         u32 i;
  75         em28xx_coredbg("requested %i buffers with size %zi\n",
  76                         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", (unsigned char)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" :
 182                                  "%02x\n", (unsigned char) val);
 183
 184         if (ret < 0)
 185                 return ret;
 186
 187         return val;
 188 }
 189
 190 int em28xx_read_reg(struct em28xx *dev, u16 reg)
 191 {
 192         return em28xx_read_reg_req(dev, USB_REQ_GET_STATUS, reg);
 193 }
 194
 195 /*
 196  * em28xx_write_regs_req()
 197  * sends data to the usb device, specifying bRequest
 198  */
 199 int em28xx_write_regs_req(struct em28xx *dev, u8 req, u16 reg, char *buf,
 200                                  int len)
 201 {
 202         int ret;
 203
 204         /*usb_control_msg seems to expect a kmalloced buffer */
 205         unsigned char *bufs;
 206
 207         if (dev->state & DEV_DISCONNECTED)
 208                 return(-ENODEV);
 209
 210         bufs = kmalloc(len, GFP_KERNEL);
 211
 212         em28xx_regdbg("req=%02x reg=%02x:", req, reg);
 213
 214         if (reg_debug) {
 215                 int i;
 216                 for (i = 0; i < len; ++i)
 217                         printk (" %02x", (unsigned char)buf[i]);
 218                 printk ("\n");
 219         }
 220
 221         if (!bufs)
 222                 return -ENOMEM;
 223         memcpy(bufs, buf, len);
 224         ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), req,
 225                               USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 226                               0x0000, reg, bufs, len, HZ);
 227         msleep(5);              /* FIXME: magic number */
 228         kfree(bufs);
 229         return ret;
 230 }
 231
 232 int em28xx_write_regs(struct em28xx *dev, u16 reg, char *buf, int len)
 233 {
 234         return em28xx_write_regs_req(dev, USB_REQ_GET_STATUS, reg, buf, len);
 235 }
 236
 237 /*
 238  * em28xx_write_reg_bits()
 239  * sets only some bits (specified by bitmask) of a register, by first reading
 240  * the actual value
 241  */
 242 static int em28xx_write_reg_bits(struct em28xx *dev, u16 reg, u8 val,
 243                                  u8 bitmask)
 244 {
 245         int oldval;
 246         u8 newval;
 247         if ((oldval = em28xx_read_reg(dev, reg)) < 0)
 248                 return oldval;
 249         newval = (((u8) oldval) & ~bitmask) | (val & bitmask);
 250         return em28xx_write_regs(dev, reg, &newval, 1);
 251 }
 252
 253 /*
 254  * em28xx_write_ac97()
 255  * write a 16 bit value to the specified AC97 address (LSB first!)
 256  */
 257 static int em28xx_write_ac97(struct em28xx *dev, u8 reg, u8 *val)
 258 {
 259         int ret, i;
 260         u8 addr = reg & 0x7f;
 261         if ((ret = em28xx_write_regs(dev, AC97LSB_REG, val, 2)) < 0)
 262                 return ret;
 263         if ((ret = em28xx_write_regs(dev, AC97ADDR_REG, &addr, 1)) < 0)
 264                 return ret;
 265
 266         /* Wait up to 50 ms for AC97 command to complete */
 267         for (i = 0; i < 10; i++) {
 268                 if ((ret = em28xx_read_reg(dev, AC97BUSY_REG)) < 0)
 269                         return ret;
 270                 if (!(ret & 0x01))
 271                         return 0;
 272                 msleep(5);
 273         }
 274         em28xx_warn ("AC97 command still being executed: not handled properly!\n");
 275         return 0;
 276 }
 277
 278 static int em28xx_set_audio_source(struct em28xx *dev)
 279 {
 280         static char *enable  = "\x08\x08";
 281         static char *disable = "\x08\x88";
 282         char *video = enable, *line = disable;
 283         int ret;
 284         u8 input;
 285
 286         if (dev->is_em2800) {
 287                 if (dev->ctl_ainput)
 288                         input = EM2800_AUDIO_SRC_LINE;
 289                 else
 290                         input = EM2800_AUDIO_SRC_TUNER;
 291
 292                 ret = em28xx_write_regs(dev, EM2800_AUDIOSRC_REG, &input, 1);
 293                 if (ret < 0)
 294                         return ret;
 295         }
 296
 297         if (dev->has_msp34xx)
 298                 input = EM28XX_AUDIO_SRC_TUNER;
 299         else {
 300                 switch (dev->ctl_ainput) {
 301                 case EM28XX_AMUX_VIDEO:
 302                         input = EM28XX_AUDIO_SRC_TUNER;
 303                         break;
 304                 case EM28XX_AMUX_LINE_IN:
 305                         input = EM28XX_AUDIO_SRC_LINE;
 306                         break;
 307                 case EM28XX_AMUX_AC97_VIDEO:
 308                         input = EM28XX_AUDIO_SRC_LINE;
 309                         break;
 310                 case EM28XX_AMUX_AC97_LINE_IN:
 311                         input = EM28XX_AUDIO_SRC_LINE;
 312                         video = disable;
 313                         line  = enable;
 314                         break;
 315                 }
 316         }
 317
 318         ret = em28xx_write_reg_bits(dev, AUDIOSRC_REG, input, 0xc0);
 319         if (ret < 0)
 320                 return ret;
 321         msleep(5);
 322
 323         /* Sets AC97 mixer registers
 324            This is seems to be needed, even for non-ac97 configs
 325          */
 326         ret = em28xx_write_ac97(dev, VIDEO_AC97, video);
 327         if (ret < 0)
 328                 return ret;
 329
 330         ret = em28xx_write_ac97(dev, LINE_IN_AC97, line);
 331
 332         return ret;
 333 }
 334
 335 int em28xx_audio_analog_set(struct em28xx *dev)
 336 {
 337         int ret;
 338         char s[2] = { 0x00, 0x00 };
 339         u8 xclk = 0x07;
 340
 341         s[0] |= 0x1f - dev->volume;
 342         s[1] |= 0x1f - dev->volume;
 343
 344         /* Mute */
 345         s[1] |= 0x80;
 346         ret = em28xx_write_ac97(dev, MASTER_AC97, s);
 347
 348         if (ret < 0)
 349                 return ret;
 350
 351         if (dev->has_12mhz_i2s)
 352                 xclk |= 0x20;
 353
 354         if (!dev->mute)
 355                 xclk |= 0x80;
 356
 357         ret = em28xx_write_reg_bits(dev, XCLK_REG, xclk, 0xa7);
 358         if (ret < 0)
 359                 return ret;
 360         msleep(10);
 361
 362         /* Selects the proper audio input */
 363         ret = em28xx_set_audio_source(dev);
 364
 365         /* Unmute device */
 366         if (!dev->mute)
 367                 s[1] &= ~0x80;
 368         ret = em28xx_write_ac97(dev, MASTER_AC97, s);
 369
 370         return ret;
 371 }
 372 EXPORT_SYMBOL_GPL(em28xx_audio_analog_set);
 373
 374 int em28xx_colorlevels_set_default(struct em28xx *dev)
 375 {
 376         em28xx_write_regs(dev, YGAIN_REG, "\x10", 1);   /* contrast */
 377         em28xx_write_regs(dev, YOFFSET_REG, "\x00", 1); /* brightness */
 378         em28xx_write_regs(dev, UVGAIN_REG, "\x10", 1);  /* saturation */
 379         em28xx_write_regs(dev, UOFFSET_REG, "\x00", 1);
 380         em28xx_write_regs(dev, VOFFSET_REG, "\x00", 1);
 381         em28xx_write_regs(dev, SHARPNESS_REG, "\x00", 1);
 382
 383         em28xx_write_regs(dev, GAMMA_REG, "\x20", 1);
 384         em28xx_write_regs(dev, RGAIN_REG, "\x20", 1);
 385         em28xx_write_regs(dev, GGAIN_REG, "\x20", 1);
 386         em28xx_write_regs(dev, BGAIN_REG, "\x20", 1);
 387         em28xx_write_regs(dev, ROFFSET_REG, "\x00", 1);
 388         em28xx_write_regs(dev, GOFFSET_REG, "\x00", 1);
 389         return em28xx_write_regs(dev, BOFFSET_REG, "\x00", 1);
 390 }
 391
 392 int em28xx_capture_start(struct em28xx *dev, int start)
 393 {
 394         int ret;
 395         /* FIXME: which is the best order? */
 396         /* video registers are sampled by VREF */
 397         if ((ret = em28xx_write_reg_bits(dev, USBSUSP_REG, start ? 0x10 : 0x00,
 398                                           0x10)) < 0)
 399                 return ret;
 400         /* enable video capture */
 401         return em28xx_write_regs(dev, VINENABLE_REG, start ? "\x67" : "\x27", 1);
 402 }
 403
 404 int em28xx_outfmt_set_yuv422(struct em28xx *dev)
 405 {
 406         em28xx_write_regs(dev, OUTFMT_REG, "\x34", 1);
 407         em28xx_write_regs(dev, VINMODE_REG, "\x10", 1);
 408         return em28xx_write_regs(dev, VINCTRL_REG, "\x11", 1);
 409 }
 410
 411 static int em28xx_accumulator_set(struct em28xx *dev, u8 xmin, u8 xmax,
 412                                   u8 ymin, u8 ymax)
 413 {
 414         em28xx_coredbg("em28xx Scale: (%d,%d)-(%d,%d)\n", xmin, ymin, xmax, ymax);
 415
 416         em28xx_write_regs(dev, XMIN_REG, &xmin, 1);
 417         em28xx_write_regs(dev, XMAX_REG, &xmax, 1);
 418         em28xx_write_regs(dev, YMIN_REG, &ymin, 1);
 419         return em28xx_write_regs(dev, YMAX_REG, &ymax, 1);
 420 }
 421
 422 static int em28xx_capture_area_set(struct em28xx *dev, u8 hstart, u8 vstart,
 423                                    u16 width, u16 height)
 424 {
 425         u8 cwidth = width;
 426         u8 cheight = height;
 427         u8 overflow = (height >> 7 & 0x02) | (width >> 8 & 0x01);
 428
 429         em28xx_coredbg("em28xx Area Set: (%d,%d)\n", (width | (overflow & 2) << 7),
 430                         (height | (overflow & 1) << 8));
 431
 432         em28xx_write_regs(dev, HSTART_REG, &hstart, 1);
 433         em28xx_write_regs(dev, VSTART_REG, &vstart, 1);
 434         em28xx_write_regs(dev, CWIDTH_REG, &cwidth, 1);
 435         em28xx_write_regs(dev, CHEIGHT_REG, &cheight, 1);
 436         return em28xx_write_regs(dev, OFLOW_REG, &overflow, 1);
 437 }
 438
 439 static int em28xx_scaler_set(struct em28xx *dev, u16 h, u16 v)
 440 {
 441         u8 mode;
 442         /* the em2800 scaler only supports scaling down to 50% */
 443         if(dev->is_em2800)
 444                 mode = (v ? 0x20 : 0x00) | (h ? 0x10 : 0x00);
 445         else {
 446                 u8 buf[2];
 447                 buf[0] = h;
 448                 buf[1] = h >> 8;
 449                 em28xx_write_regs(dev, HSCALELOW_REG, (char *)buf, 2);
 450                 buf[0] = v;
 451                 buf[1] = v >> 8;
 452                 em28xx_write_regs(dev, VSCALELOW_REG, (char *)buf, 2);
 453                 /* it seems that both H and V scalers must be active to work correctly */
 454                 mode = (h || v)? 0x30: 0x00;
 455         }
 456         return em28xx_write_reg_bits(dev, COMPR_REG, mode, 0x30);
 457 }
 458
 459 /* FIXME: this only function read values from dev */
 460 int em28xx_resolution_set(struct em28xx *dev)
 461 {
 462         int width, height;
 463         width = norm_maxw(dev);
 464         height = norm_maxh(dev) >> 1;
 465
 466         em28xx_outfmt_set_yuv422(dev);
 467         em28xx_accumulator_set(dev, 1, (width - 4) >> 2, 1, (height - 4) >> 2);
 468         em28xx_capture_area_set(dev, 0, 0, width >> 2, height >> 2);
 469         return em28xx_scaler_set(dev, dev->hscale, dev->vscale);
 470 }
 471
 472
 473 /******************* isoc transfer handling ****************************/
 474
 475 #ifdef ENABLE_DEBUG_ISOC_FRAMES
 476 static void em28xx_isoc_dump(struct urb *urb)
 477 {
 478         int len = 0;
 479         int ntrans = 0;
 480         int i;
 481
 482         printk(KERN_DEBUG "isocIrq: sf=%d np=%d ec=%x\n",
 483                urb->start_frame, urb->number_of_packets,
 484                urb->error_count);
 485         for (i = 0; i < urb->number_of_packets; i++) {
 486                 unsigned char *buf =
 487                                 urb->transfer_buffer +
 488                                 urb->iso_frame_desc[i].offset;
 489                 int alen = urb->iso_frame_desc[i].actual_length;
 490                 if (alen > 0) {
 491                         if (buf[0] == 0x88) {
 492                                 ntrans++;
 493                                 len += alen;
 494                         } else if (buf[0] == 0x22) {
 495                                 printk(KERN_DEBUG
 496                                                 "= l=%d nt=%d bpp=%d\n",
 497                                 len - 4 * ntrans, ntrans,
 498                                 ntrans == 0 ? 0 : len / ntrans);
 499                                 ntrans = 1;
 500                                 len = alen;
 501                         } else
 502                                 printk(KERN_DEBUG "!\n");
 503                 }
 504                 printk(KERN_DEBUG "   n=%d s=%d al=%d %x\n", i,
 505                        urb->iso_frame_desc[i].status,
 506                        urb->iso_frame_desc[i].actual_length,
 507                        (unsigned int)
 508                                        *((unsigned char *)(urb->transfer_buffer +
 509                                        urb->iso_frame_desc[i].
 510                                        offset)));
 511         }
 512 }
 513 #endif
 514
 515 static inline int em28xx_isoc_video(struct em28xx *dev,struct em28xx_frame_t **f,
 516                                     unsigned long *lock_flags, unsigned char buf)
 517 {
 518         if (!(buf & 0x01)) {
 519                 if ((*f)->state == F_GRABBING) {
 520                         /*previous frame is incomplete */
 521                         if ((*f)->fieldbytesused < dev->field_size) {
 522                                 (*f)->state = F_ERROR;
 523                                 em28xx_isocdbg ("dropping incomplete bottom field (%i missing bytes)",
 524                                          dev->field_size-(*f)->fieldbytesused);
 525                         } else {
 526                                 (*f)->state = F_DONE;
 527                                 (*f)->buf.bytesused = dev->frame_size;
 528                         }
 529                 }
 530                 if ((*f)->state == F_DONE || (*f)->state == F_ERROR) {
 531                         /* move current frame to outqueue and get next free buffer from inqueue */
 532                         spin_lock_irqsave(&dev-> queue_lock, *lock_flags);
 533                         list_move_tail(&(*f)->frame, &dev->outqueue);
 534                         if (!list_empty(&dev->inqueue))
 535                                 (*f) = list_entry(dev-> inqueue.next,
 536                         struct em28xx_frame_t,frame);
 537                         else
 538                                 (*f) = NULL;
 539                         spin_unlock_irqrestore(&dev->queue_lock,*lock_flags);
 540                 }
 541                 if (!(*f)) {
 542                         em28xx_isocdbg ("new frame but no buffer is free");
 543                         return -1;
 544                 }
 545                 do_gettimeofday(&(*f)->buf.timestamp);
 546                 (*f)->buf.sequence = ++dev->frame_count;
 547                 (*f)->buf.field = V4L2_FIELD_INTERLACED;
 548                 (*f)->state = F_GRABBING;
 549                 (*f)->buf.bytesused = 0;
 550                 (*f)->top_field = 1;
 551                 (*f)->fieldbytesused = 0;
 552         } else {
 553                                         /* acquiring bottom field */
 554                 if ((*f)->state == F_GRABBING) {
 555                         if (!(*f)->top_field) {
 556                                 (*f)->state = F_ERROR;
 557                                 em28xx_isocdbg ("unexpected begin of bottom field; discarding it");
 558                         } else if ((*f)-> fieldbytesused < dev->field_size - 172) {
 559                                 (*f)->state = F_ERROR;
 560                                 em28xx_isocdbg ("dropping incomplete top field (%i missing bytes)",
 561                                          dev->field_size-(*f)->fieldbytesused);
 562                         } else {
 563                                 (*f)->top_field = 0;
 564                                 (*f)->fieldbytesused = 0;
 565                         }
 566                 }
 567         }
 568         return (0);
 569 }
 570
 571 static inline void em28xx_isoc_video_copy(struct em28xx *dev,
 572                                           struct em28xx_frame_t **f, unsigned char *buf, int len)
 573 {
 574         void *fieldstart, *startwrite, *startread;
 575         int linesdone, currlinedone, offset, lencopy,remain;
 576
 577         if(dev->frame_size != (*f)->buf.length){
 578                 em28xx_err("frame_size %i and buf.length %i are different!!!\n",dev->frame_size,(*f)->buf.length);
 579                 return;
 580         }
 581
 582         if ((*f)->fieldbytesused + len > dev->field_size)
 583                 len =dev->field_size - (*f)->fieldbytesused;
 584
 585         if (buf[0] != 0x88 && buf[0] != 0x22) {
 586                 em28xx_isocdbg("frame is not complete\n");
 587                 startread = buf;
 588                 len+=4;
 589         } else
 590                 startread = buf + 4;
 591
 592         remain = len;
 593
 594         if ((*f)->top_field)
 595                 fieldstart = (*f)->bufmem;
 596         else
 597                 fieldstart = (*f)->bufmem + dev->bytesperline;
 598
 599         linesdone = (*f)->fieldbytesused / dev->bytesperline;
 600         currlinedone = (*f)->fieldbytesused % dev->bytesperline;
 601         offset = linesdone * dev->bytesperline * 2 + currlinedone;
 602         startwrite = fieldstart + offset;
 603         lencopy = dev->bytesperline - currlinedone;
 604         lencopy = lencopy > remain ? remain : lencopy;
 605
 606         memcpy(startwrite, startread, lencopy);
 607         remain -= lencopy;
 608
 609         while (remain > 0) {
 610                 startwrite += lencopy + dev->bytesperline;
 611                 startread += lencopy;
 612                 if (dev->bytesperline > remain)
 613                         lencopy = remain;
 614                 else
 615                         lencopy = dev->bytesperline;
 616
 617                 memcpy(startwrite, startread, lencopy);
 618                 remain -= lencopy;
 619         }
 620
 621         (*f)->fieldbytesused += len;
 622 }
 623
 624 /*
 625  * em28xx_isoIrq()
 626  * handles the incoming isoc urbs and fills the frames from our inqueue
 627  */
 628 static void em28xx_isocIrq(struct urb *urb)
 629 {
 630         struct em28xx *dev = urb->context;
 631         int i, status;
 632         struct em28xx_frame_t **f;
 633         unsigned long lock_flags;
 634
 635         if (!dev)
 636                 return;
 637 #ifdef ENABLE_DEBUG_ISOC_FRAMES
 638         if (isoc_debug>1)
 639                 em28xx_isoc_dump(urb);
 640 #endif
 641
 642         if (urb->status == -ENOENT)
 643                 return;
 644
 645         f = &dev->frame_current;
 646
 647         if (dev->stream == STREAM_INTERRUPT) {
 648                 dev->stream = STREAM_OFF;
 649                 if ((*f))
 650                         (*f)->state = F_QUEUED;
 651                 em28xx_isocdbg("stream interrupted");
 652                 wake_up_interruptible(&dev->wait_stream);
 653         }
 654
 655         if ((dev->state & DEV_DISCONNECTED) || (dev->state & DEV_MISCONFIGURED))
 656                 return;
 657
 658         if (dev->stream == STREAM_ON && !list_empty(&dev->inqueue)) {
 659                 if (!(*f))
 660                         (*f) = list_entry(dev->inqueue.next,
 661                 struct em28xx_frame_t, frame);
 662
 663                 for (i = 0; i < urb->number_of_packets; i++) {
 664                         unsigned char *buf = urb->transfer_buffer +
 665                                         urb->iso_frame_desc[i].offset;
 666                         int len = urb->iso_frame_desc[i].actual_length - 4;
 667
 668                         if (urb->iso_frame_desc[i].status) {
 669                                 em28xx_isocdbg("data error: [%d] len=%d, status=%d", i,
 670                                         urb->iso_frame_desc[i].actual_length,
 671                                         urb->iso_frame_desc[i].status);
 672                                 if (urb->iso_frame_desc[i].status != -EPROTO)
 673                                         continue;
 674                         }
 675                         if (urb->iso_frame_desc[i].actual_length <= 0) {
 676                                 em28xx_isocdbg("packet %d is empty",i);
 677                                 continue;
 678                         }
 679                         if (urb->iso_frame_desc[i].actual_length >
 680                             urb->iso_frame_desc[i].length) {
 681                                 em28xx_isocdbg("packet bigger than packet size");
 682                                 continue;
 683                         }
 684                         /*new frame */
 685                         if (buf[0] == 0x22 && buf[1] == 0x5a) {
 686                                 em28xx_isocdbg("Video frame, length=%i!",len);
 687
 688                                 if (em28xx_isoc_video(dev,f,&lock_flags,buf[2]))
 689                                 break;
 690                         } else if (buf[0]==0x33 && buf[1]==0x95 && buf[2]==0x00) {
 691                                 em28xx_isocdbg("VBI HEADER!!!");
 692                         }
 693
 694                         /* actual copying */
 695                         if ((*f)->state == F_GRABBING) {
 696                                 em28xx_isoc_video_copy(dev,f,buf, len);
 697                         }
 698                 }
 699         }
 700
 701         for (i = 0; i < urb->number_of_packets; i++) {
 702                 urb->iso_frame_desc[i].status = 0;
 703                 urb->iso_frame_desc[i].actual_length = 0;
 704         }
 705
 706         urb->status = 0;
 707         if ((status = usb_submit_urb(urb, GFP_ATOMIC))) {
 708                 em28xx_errdev("resubmit of urb failed (error=%i)\n", status);
 709                 dev->state |= DEV_MISCONFIGURED;
 710         }
 711         wake_up_interruptible(&dev->wait_frame);
 712         return;
 713 }
 714
 715 /*
 716  * em28xx_uninit_isoc()
 717  * deallocates the buffers and urbs allocated during em28xx_init_iosc()
 718  */
 719 void em28xx_uninit_isoc(struct em28xx *dev)
 720 {
 721         int i;
 722
 723         for (i = 0; i < EM28XX_NUM_BUFS; i++) {
 724                 if (dev->urb[i]) {
 725                         usb_kill_urb(dev->urb[i]);
 726                         if (dev->transfer_buffer[i]) {
 727                                 usb_buffer_free(dev->udev,
 728                                                 dev->urb[i]->transfer_buffer_length,
 729                                                 dev->transfer_buffer[i],
 730                                                 dev->urb[i]->transfer_dma);
 731                         }
 732                         usb_free_urb(dev->urb[i]);
 733                 }
 734                 dev->urb[i] = NULL;
 735                 dev->transfer_buffer[i] = NULL;
 736         }
 737         em28xx_capture_start(dev, 0);
 738 }
 739
 740 /*
 741  * em28xx_init_isoc()
 742  * allocates transfer buffers and submits the urbs for isoc transfer
 743  */
 744 int em28xx_init_isoc(struct em28xx *dev)
 745 {
 746         /* change interface to 3 which allows the biggest packet sizes */
 747         int i, errCode;
 748         int sb_size;
 749
 750         em28xx_set_alternate(dev);
 751         sb_size = EM28XX_NUM_PACKETS * dev->max_pkt_size;
 752
 753         /* reset streaming vars */
 754         dev->frame_current = NULL;
 755         dev->frame_count = 0;
 756
 757         /* allocate urbs */
 758         for (i = 0; i < EM28XX_NUM_BUFS; i++) {
 759                 struct urb *urb;
 760                 int j;
 761                 /* allocate transfer buffer */
 762                 urb = usb_alloc_urb(EM28XX_NUM_PACKETS, GFP_KERNEL);
 763                 if (!urb){
 764                         em28xx_errdev("cannot alloc urb %i\n", i);
 765                         em28xx_uninit_isoc(dev);
 766                         return -ENOMEM;
 767                 }
 768                 dev->transfer_buffer[i] = usb_buffer_alloc(dev->udev, sb_size,
 769                                                            GFP_KERNEL,
 770                                                            &urb->transfer_dma);
 771                 if (!dev->transfer_buffer[i]) {
 772                         em28xx_errdev
 773                                         ("unable to allocate %i bytes for transfer buffer %i\n",
 774                                          sb_size, i);
 775                         em28xx_uninit_isoc(dev);
 776                         usb_free_urb(urb);
 777                         return -ENOMEM;
 778                 }
 779                 memset(dev->transfer_buffer[i], 0, sb_size);
 780                 urb->dev = dev->udev;
 781                 urb->context = dev;
 782                 urb->pipe = usb_rcvisocpipe(dev->udev, 0x82);
 783                 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
 784                 urb->interval = 1;
 785                 urb->transfer_buffer = dev->transfer_buffer[i];
 786                 urb->complete = em28xx_isocIrq;
 787                 urb->number_of_packets = EM28XX_NUM_PACKETS;
 788                 urb->transfer_buffer_length = sb_size;
 789                 for (j = 0; j < EM28XX_NUM_PACKETS; j++) {
 790                         urb->iso_frame_desc[j].offset = j * dev->max_pkt_size;
 791                         urb->iso_frame_desc[j].length = dev->max_pkt_size;
 792                 }
 793                 dev->urb[i] = urb;
 794         }
 795
 796         /* submit urbs */
 797         em28xx_coredbg("Submitting %d urbs of %d packets (%d each)\n",
 798                        EM28XX_NUM_BUFS, EM28XX_NUM_PACKETS, dev->max_pkt_size);
 799         for (i = 0; i < EM28XX_NUM_BUFS; i++) {
 800                 errCode = usb_submit_urb(dev->urb[i], GFP_KERNEL);
 801                 if (errCode) {
 802                         em28xx_errdev("submit of urb %i failed (error=%i)\n", i,
 803                                       errCode);
 804                         em28xx_uninit_isoc(dev);
 805                         return errCode;
 806                 }
 807         }
 808
 809         return 0;
 810 }
 811
 812 int em28xx_set_alternate(struct em28xx *dev)
 813 {
 814         int errCode, prev_alt = dev->alt;
 815         int i;
 816         unsigned int min_pkt_size = dev->bytesperline+4;
 817
 818         /* When image size is bigger than a ceirtain value,
 819            the frame size should be increased, otherwise, only
 820            green screen will be received.
 821          */
 822         if (dev->frame_size > 720*240*2)
 823                 min_pkt_size *= 2;
 824
 825         for (i = 0; i < dev->num_alt; i++)
 826                 if (dev->alt_max_pkt_size[i] >= min_pkt_size)
 827                         break;
 828         dev->alt = i;
 829
 830         if (dev->alt != prev_alt) {
 831                 em28xx_coredbg("minimum isoc packet size: %u (alt=%d)\n",
 832                                 min_pkt_size, dev->alt);
 833                 dev->max_pkt_size = dev->alt_max_pkt_size[dev->alt];
 834                 em28xx_coredbg("setting alternate %d with wMaxPacketSize=%u\n",
 835                                dev->alt, dev->max_pkt_size);
 836                 errCode = usb_set_interface(dev->udev, 0, dev->alt);
 837                 if (errCode < 0) {
 838                         em28xx_errdev ("cannot change alternate number to %d (error=%i)\n",
 839                                         dev->alt, errCode);
 840                         return errCode;
 841                 }
 842         }
 843         return 0;
 844 }