drivers/media/usb/stk1160/stk1160-video.c

   1 /*
   2  * STK1160 driver
   3  *
   4  * Copyright (C) 2012 Ezequiel Garcia
   5  * <elezegarcia--a.t--gmail.com>
   6  *
   7  * Based on Easycap driver by R.M. Thomas
   8  *      Copyright (C) 2010 R.M. Thomas
   9  *      <rmthomas--a.t--sciolus.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/usb.h>
  25 #include <linux/slab.h>
  26 #include <linux/ratelimit.h>
  27
  28 #include "stk1160.h"
  29
  30 static unsigned int debug;
  31 module_param(debug, int, 0644);
  32 MODULE_PARM_DESC(debug, "enable debug messages");
  33
  34 static inline void print_err_status(struct stk1160 *dev,
  35                                      int packet, int status)
  36 {
  37         char *errmsg = "Unknown";
  38
  39         switch (status) {
  40         case -ENOENT:
  41                 errmsg = "unlinked synchronously";
  42                 break;
  43         case -ECONNRESET:
  44                 errmsg = "unlinked asynchronously";
  45                 break;
  46         case -ENOSR:
  47                 errmsg = "Buffer error (overrun)";
  48                 break;
  49         case -EPIPE:
  50                 errmsg = "Stalled (device not responding)";
  51                 break;
  52         case -EOVERFLOW:
  53                 errmsg = "Babble (bad cable?)";
  54                 break;
  55         case -EPROTO:
  56                 errmsg = "Bit-stuff error (bad cable?)";
  57                 break;
  58         case -EILSEQ:
  59                 errmsg = "CRC/Timeout (could be anything)";
  60                 break;
  61         case -ETIME:
  62                 errmsg = "Device does not respond";
  63                 break;
  64         }
  65
  66         if (packet < 0)
  67                 printk_ratelimited(KERN_WARNING "URB status %d [%s].\n",
  68                                 status, errmsg);
  69         else
  70                 printk_ratelimited(KERN_INFO "URB packet %d, status %d [%s].\n",
  71                                packet, status, errmsg);
  72 }
  73
  74 static inline
  75 struct stk1160_buffer *stk1160_next_buffer(struct stk1160 *dev)
  76 {
  77         struct stk1160_buffer *buf = NULL;
  78         unsigned long flags = 0;
  79
  80         /* Current buffer must be NULL when this functions gets called */
  81         WARN_ON(dev->isoc_ctl.buf);
  82
  83         spin_lock_irqsave(&dev->buf_lock, flags);
  84         if (!list_empty(&dev->avail_bufs)) {
  85                 buf = list_first_entry(&dev->avail_bufs,
  86                                 struct stk1160_buffer, list);
  87                 list_del(&buf->list);
  88         }
  89         spin_unlock_irqrestore(&dev->buf_lock, flags);
  90
  91         return buf;
  92 }
  93
  94 static inline
  95 void stk1160_buffer_done(struct stk1160 *dev)
  96 {
  97         struct stk1160_buffer *buf = dev->isoc_ctl.buf;
  98
  99         buf->vb.sequence = dev->sequence++;
 100         buf->vb.field = V4L2_FIELD_INTERLACED;
 101         buf->vb.vb2_buf.timestamp = ktime_get_ns();
 102
 103         vb2_set_plane_payload(&buf->vb.vb2_buf, 0, buf->bytesused);
 104         vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
 105
 106         dev->isoc_ctl.buf = NULL;
 107 }
 108
 109 static inline
 110 void stk1160_copy_video(struct stk1160 *dev, u8 *src, int len)
 111 {
 112         int linesdone, lineoff, lencopy;
 113         int bytesperline = dev->width * 2;
 114         struct stk1160_buffer *buf = dev->isoc_ctl.buf;
 115         u8 *dst = buf->mem;
 116         int remain;
 117
 118         /*
 119          * TODO: These stk1160_dbg are very spammy!
 120          * We should 1) check why we are getting them
 121          * and 2) add ratelimit.
 122          *
 123          * UPDATE: One of the reasons (the only one?) for getting these
 124          * is incorrect standard (mismatch between expected and configured).
 125          * So perhaps, we could add a counter for errors. When the counter
 126          * reaches some value, we simply stop streaming.
 127          */
 128
 129         len -= 4;
 130         src += 4;
 131
 132         remain = len;
 133
 134         linesdone = buf->pos / bytesperline;
 135         lineoff = buf->pos % bytesperline; /* offset in current line */
 136
 137         if (!buf->odd)
 138                 dst += bytesperline;
 139
 140         /* Multiply linesdone by two, to take account of the other field */
 141         dst += linesdone * bytesperline * 2 + lineoff;
 142
 143         /* Copy the remaining of current line */
 144         if (remain < (bytesperline - lineoff))
 145                 lencopy = remain;
 146         else
 147                 lencopy = bytesperline - lineoff;
 148
 149         /*
 150          * Check if we have enough space left in the buffer.
 151          * In that case, we force loop exit after copy.
 152          */
 153         if (lencopy > buf->bytesused - buf->length) {
 154                 lencopy = buf->bytesused - buf->length;
 155                 remain = lencopy;
 156         }
 157
 158         /* Check if the copy is done */
 159         if (lencopy == 0 || remain == 0)
 160                 return;
 161
 162         /* Let the bug hunt begin! sanity checks! */
 163         if (lencopy < 0) {
 164                 stk1160_dbg("copy skipped: negative lencopy\n");
 165                 return;
 166         }
 167
 168         if ((unsigned long)dst + lencopy >
 169                 (unsigned long)buf->mem + buf->length) {
 170                 printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
 171                 return;
 172         }
 173
 174         memcpy(dst, src, lencopy);
 175
 176         buf->bytesused += lencopy;
 177         buf->pos += lencopy;
 178         remain -= lencopy;
 179
 180         /* Copy current field line by line, interlacing with the other field */
 181         while (remain > 0) {
 182
 183                 dst += lencopy + bytesperline;
 184                 src += lencopy;
 185
 186                 /* Copy one line at a time */
 187                 if (remain < bytesperline)
 188                         lencopy = remain;
 189                 else
 190                         lencopy = bytesperline;
 191
 192                 /*
 193                  * Check if we have enough space left in the buffer.
 194                  * In that case, we force loop exit after copy.
 195                  */
 196                 if (lencopy > buf->bytesused - buf->length) {
 197                         lencopy = buf->bytesused - buf->length;
 198                         remain = lencopy;
 199                 }
 200
 201                 /* Check if the copy is done */
 202                 if (lencopy == 0 || remain == 0)
 203                         return;
 204
 205                 if (lencopy < 0) {
 206                         printk_ratelimited(KERN_WARNING "stk1160: negative lencopy detected\n");
 207                         return;
 208                 }
 209
 210                 if ((unsigned long)dst + lencopy >
 211                         (unsigned long)buf->mem + buf->length) {
 212                         printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
 213                         return;
 214                 }
 215
 216                 memcpy(dst, src, lencopy);
 217                 remain -= lencopy;
 218
 219                 buf->bytesused += lencopy;
 220                 buf->pos += lencopy;
 221         }
 222 }
 223
 224 /*
 225  * Controls the isoc copy of each urb packet
 226  */
 227 static void stk1160_process_isoc(struct stk1160 *dev, struct urb *urb)
 228 {
 229         int i, len, status;
 230         u8 *p;
 231
 232         if (!dev) {
 233                 stk1160_warn("%s called with null device\n", __func__);
 234                 return;
 235         }
 236
 237         if (urb->status < 0) {
 238                 /* Print status and drop current packet (or field?) */
 239                 print_err_status(dev, -1, urb->status);
 240                 return;
 241         }
 242
 243         for (i = 0; i < urb->number_of_packets; i++) {
 244                 status = urb->iso_frame_desc[i].status;
 245                 if (status < 0) {
 246                         print_err_status(dev, i, status);
 247                         continue;
 248                 }
 249
 250                 /* Get packet actual length and pointer to data */
 251                 p = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
 252                 len = urb->iso_frame_desc[i].actual_length;
 253
 254                 /* Empty packet */
 255                 if (len <= 4)
 256                         continue;
 257
 258                 /*
 259                  * An 8-byte packet sequence means end of field.
 260                  * So if we don't have any packet, we start receiving one now
 261                  * and if we do have a packet, then we are done with it.
 262                  *
 263                  * These end of field packets are always 0xc0 or 0x80,
 264                  * but not always 8-byte long so we don't check packet length.
 265                  */
 266                 if (p[0] == 0xc0) {
 267
 268                         /*
 269                          * If first byte is 0xc0 then we received
 270                          * second field, and frame has ended.
 271                          */
 272                         if (dev->isoc_ctl.buf != NULL)
 273                                 stk1160_buffer_done(dev);
 274
 275                         dev->isoc_ctl.buf = stk1160_next_buffer(dev);
 276                         if (dev->isoc_ctl.buf == NULL)
 277                                 return;
 278                 }
 279
 280                 /*
 281                  * If we don't have a buffer here, then it means we
 282                  * haven't found the start mark sequence.
 283                  */
 284                 if (dev->isoc_ctl.buf == NULL)
 285                         continue;
 286
 287                 if (p[0] == 0xc0 || p[0] == 0x80) {
 288
 289                         /* We set next packet parity and
 290                          * continue to get next one
 291                          */
 292                         dev->isoc_ctl.buf->odd = *p & 0x40;
 293                         dev->isoc_ctl.buf->pos = 0;
 294                         continue;
 295                 }
 296
 297                 stk1160_copy_video(dev, p, len);
 298         }
 299 }
 300
 301
 302 /*
 303  * IRQ callback, called by URB callback
 304  */
 305 static void stk1160_isoc_irq(struct urb *urb)
 306 {
 307         int i, rc;
 308         struct stk1160 *dev = urb->context;
 309
 310         switch (urb->status) {
 311         case 0:
 312                 break;
 313         case -ECONNRESET:   /* kill */
 314         case -ENOENT:
 315         case -ESHUTDOWN:
 316                 /* TODO: check uvc driver: he frees the queue here */
 317                 return;
 318         default:
 319                 stk1160_err("urb error! status %d\n", urb->status);
 320                 return;
 321         }
 322
 323         stk1160_process_isoc(dev, urb);
 324
 325         /* Reset urb buffers */
 326         for (i = 0; i < urb->number_of_packets; i++) {
 327                 urb->iso_frame_desc[i].status = 0;
 328                 urb->iso_frame_desc[i].actual_length = 0;
 329         }
 330
 331         rc = usb_submit_urb(urb, GFP_ATOMIC);
 332         if (rc)
 333                 stk1160_err("urb re-submit failed (%d)\n", rc);
 334 }
 335
 336 /*
 337  * Cancel urbs
 338  * This function can't be called in atomic context
 339  */
 340 void stk1160_cancel_isoc(struct stk1160 *dev)
 341 {
 342         int i, num_bufs = dev->isoc_ctl.num_bufs;
 343
 344         /*
 345          * This check is not necessary, but we add it
 346          * to avoid a spurious debug message
 347          */
 348         if (!num_bufs)
 349                 return;
 350
 351         stk1160_dbg("killing %d urbs...\n", num_bufs);
 352
 353         for (i = 0; i < num_bufs; i++) {
 354
 355                 /*
 356                  * To kill urbs we can't be in atomic context.
 357                  * We don't care for NULL pointer since
 358                  * usb_kill_urb allows it.
 359                  */
 360                 usb_kill_urb(dev->isoc_ctl.urb[i]);
 361         }
 362
 363         stk1160_dbg("all urbs killed\n");
 364 }
 365
 366 /*
 367  * Releases urb and transfer buffers
 368  * Obviusly, associated urb must be killed before releasing it.
 369  */
 370 void stk1160_free_isoc(struct stk1160 *dev)
 371 {
 372         struct urb *urb;
 373         int i, num_bufs = dev->isoc_ctl.num_bufs;
 374
 375         stk1160_dbg("freeing %d urb buffers...\n", num_bufs);
 376
 377         for (i = 0; i < num_bufs; i++) {
 378
 379                 urb = dev->isoc_ctl.urb[i];
 380                 if (urb) {
 381
 382                         if (dev->isoc_ctl.transfer_buffer[i]) {
 383 #ifndef CONFIG_DMA_NONCOHERENT
 384                                 usb_free_coherent(dev->udev,
 385                                         urb->transfer_buffer_length,
 386                                         dev->isoc_ctl.transfer_buffer[i],
 387                                         urb->transfer_dma);
 388 #else
 389                                 kfree(dev->isoc_ctl.transfer_buffer[i]);
 390 #endif
 391                         }
 392                         usb_free_urb(urb);
 393                         dev->isoc_ctl.urb[i] = NULL;
 394                 }
 395                 dev->isoc_ctl.transfer_buffer[i] = NULL;
 396         }
 397
 398         kfree(dev->isoc_ctl.urb);
 399         kfree(dev->isoc_ctl.transfer_buffer);
 400
 401         dev->isoc_ctl.urb = NULL;
 402         dev->isoc_ctl.transfer_buffer = NULL;
 403         dev->isoc_ctl.num_bufs = 0;
 404
 405         stk1160_dbg("all urb buffers freed\n");
 406 }
 407
 408 /*
 409  * Helper for cancelling and freeing urbs
 410  * This function can't be called in atomic context
 411  */
 412 void stk1160_uninit_isoc(struct stk1160 *dev)
 413 {
 414         stk1160_cancel_isoc(dev);
 415         stk1160_free_isoc(dev);
 416 }
 417
 418 /*
 419  * Allocate URBs
 420  */
 421 int stk1160_alloc_isoc(struct stk1160 *dev)
 422 {
 423         struct urb *urb;
 424         int i, j, k, sb_size, max_packets, num_bufs;
 425
 426         /*
 427          * It may be necessary to release isoc here,
 428          * since isoc are only released on disconnection.
 429          * (see new_pkt_size flag)
 430          */
 431         if (dev->isoc_ctl.num_bufs)
 432                 stk1160_uninit_isoc(dev);
 433
 434         stk1160_dbg("allocating urbs...\n");
 435
 436         num_bufs = STK1160_NUM_BUFS;
 437         max_packets = STK1160_NUM_PACKETS;
 438         sb_size = max_packets * dev->max_pkt_size;
 439
 440         dev->isoc_ctl.buf = NULL;
 441         dev->isoc_ctl.max_pkt_size = dev->max_pkt_size;
 442         dev->isoc_ctl.urb = kcalloc(num_bufs, sizeof(void *), GFP_KERNEL);
 443         if (!dev->isoc_ctl.urb) {
 444                 stk1160_err("out of memory for urb array\n");
 445                 return -ENOMEM;
 446         }
 447
 448         dev->isoc_ctl.transfer_buffer = kcalloc(num_bufs, sizeof(void *),
 449                                                 GFP_KERNEL);
 450         if (!dev->isoc_ctl.transfer_buffer) {
 451                 stk1160_err("out of memory for usb transfers\n");
 452                 kfree(dev->isoc_ctl.urb);
 453                 return -ENOMEM;
 454         }
 455
 456         /* allocate urbs and transfer buffers */
 457         for (i = 0; i < num_bufs; i++) {
 458
 459                 urb = usb_alloc_urb(max_packets, GFP_KERNEL);
 460                 if (!urb)
 461                         goto free_i_bufs;
 462                 dev->isoc_ctl.urb[i] = urb;
 463
 464 #ifndef CONFIG_DMA_NONCOHERENT
 465                 dev->isoc_ctl.transfer_buffer[i] = usb_alloc_coherent(dev->udev,
 466                         sb_size, GFP_KERNEL, &urb->transfer_dma);
 467 #else
 468                 dev->isoc_ctl.transfer_buffer[i] = kmalloc(sb_size, GFP_KERNEL);
 469 #endif
 470                 if (!dev->isoc_ctl.transfer_buffer[i]) {
 471                         stk1160_err("cannot alloc %d bytes for tx[%d] buffer\n",
 472                                 sb_size, i);
 473
 474                         /* Not enough transfer buffers, so just give up */
 475                         if (i < STK1160_MIN_BUFS)
 476                                 goto free_i_bufs;
 477                         goto nomore_tx_bufs;
 478                 }
 479                 memset(dev->isoc_ctl.transfer_buffer[i], 0, sb_size);
 480
 481                 /*
 482                  * FIXME: Where can I get the endpoint?
 483                  */
 484                 urb->dev = dev->udev;
 485                 urb->pipe = usb_rcvisocpipe(dev->udev, STK1160_EP_VIDEO);
 486                 urb->transfer_buffer = dev->isoc_ctl.transfer_buffer[i];
 487                 urb->transfer_buffer_length = sb_size;
 488                 urb->complete = stk1160_isoc_irq;
 489                 urb->context = dev;
 490                 urb->interval = 1;
 491                 urb->start_frame = 0;
 492                 urb->number_of_packets = max_packets;
 493 #ifndef CONFIG_DMA_NONCOHERENT
 494                 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
 495 #else
 496                 urb->transfer_flags = URB_ISO_ASAP;
 497 #endif
 498
 499                 k = 0;
 500                 for (j = 0; j < max_packets; j++) {
 501                         urb->iso_frame_desc[j].offset = k;
 502                         urb->iso_frame_desc[j].length =
 503                                         dev->isoc_ctl.max_pkt_size;
 504                         k += dev->isoc_ctl.max_pkt_size;
 505                 }
 506         }
 507
 508         stk1160_dbg("%d urbs allocated\n", num_bufs);
 509
 510         /* At last we can say we have some buffers */
 511         dev->isoc_ctl.num_bufs = num_bufs;
 512
 513         return 0;
 514
 515 nomore_tx_bufs:
 516         /*
 517          * Failed to allocate desired buffer count. However, we may have
 518          * enough to work fine, so we just free the extra urb,
 519          * store the allocated count and keep going, fingers crossed!
 520          */
 521         usb_free_urb(dev->isoc_ctl.urb[i]);
 522         dev->isoc_ctl.urb[i] = NULL;
 523
 524         stk1160_warn("%d urbs allocated. Trying to continue...\n", i - 1);
 525
 526         dev->isoc_ctl.num_bufs = i - 1;
 527
 528         return 0;
 529
 530 free_i_bufs:
 531         /* Save the allocated buffers so far, so we can properly free them */
 532         dev->isoc_ctl.num_bufs = i+1;
 533         stk1160_free_isoc(dev);
 534         return -ENOMEM;
 535 }
 536