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 synchronuously";
  42                 break;
  43         case -ECONNRESET:
  44                 errmsg = "unlinked asynchronuously";
  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.planes[0].bytesused = buf->bytesused;
 102         v4l2_get_timestamp(&buf->vb.timestamp);
 103
 104         vb2_set_plane_payload(&buf->vb.vb2_buf, 0, buf->bytesused);
 105         vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
 106
 107         dev->isoc_ctl.buf = NULL;
 108 }
 109
 110 static inline
 111 void stk1160_copy_video(struct stk1160 *dev, u8 *src, int len)
 112 {
 113         int linesdone, lineoff, lencopy;
 114         int bytesperline = dev->width * 2;
 115         struct stk1160_buffer *buf = dev->isoc_ctl.buf;
 116         u8 *dst = buf->mem;
 117         int remain;
 118
 119         /*
 120          * TODO: These stk1160_dbg are very spammy!
 121          * We should 1) check why we are getting them
 122          * and 2) add ratelimit.
 123          *
 124          * UPDATE: One of the reasons (the only one?) for getting these
 125          * is incorrect standard (mismatch between expected and configured).
 126          * So perhaps, we could add a counter for errors. When the counter
 127          * reaches some value, we simply stop streaming.
 128          */
 129
 130         len -= 4;
 131         src += 4;
 132
 133         remain = len;
 134
 135         linesdone = buf->pos / bytesperline;
 136         lineoff = buf->pos % bytesperline; /* offset in current line */
 137
 138         if (!buf->odd)
 139                 dst += bytesperline;
 140
 141         /* Multiply linesdone by two, to take account of the other field */
 142         dst += linesdone * bytesperline * 2 + lineoff;
 143
 144         /* Copy the remaining of current line */
 145         if (remain < (bytesperline - lineoff))
 146                 lencopy = remain;
 147         else
 148                 lencopy = bytesperline - lineoff;
 149
 150         /*
 151          * Check if we have enough space left in the buffer.
 152          * In that case, we force loop exit after copy.
 153          */
 154         if (lencopy > buf->bytesused - buf->length) {
 155                 lencopy = buf->bytesused - buf->length;
 156                 remain = lencopy;
 157         }
 158
 159         /* Check if the copy is done */
 160         if (lencopy == 0 || remain == 0)
 161                 return;
 162
 163         /* Let the bug hunt begin! sanity checks! */
 164         if (lencopy < 0) {
 165                 stk1160_dbg("copy skipped: negative lencopy\n");
 166                 return;
 167         }
 168
 169         if ((unsigned long)dst + lencopy >
 170                 (unsigned long)buf->mem + buf->length) {
 171                 printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
 172                 return;
 173         }
 174
 175         memcpy(dst, src, lencopy);
 176
 177         buf->bytesused += lencopy;
 178         buf->pos += lencopy;
 179         remain -= lencopy;
 180
 181         /* Copy current field line by line, interlacing with the other field */
 182         while (remain > 0) {
 183
 184                 dst += lencopy + bytesperline;
 185                 src += lencopy;
 186
 187                 /* Copy one line at a time */
 188                 if (remain < bytesperline)
 189                         lencopy = remain;
 190                 else
 191                         lencopy = bytesperline;
 192
 193                 /*
 194                  * Check if we have enough space left in the buffer.
 195                  * In that case, we force loop exit after copy.
 196                  */
 197                 if (lencopy > buf->bytesused - buf->length) {
 198                         lencopy = buf->bytesused - buf->length;
 199                         remain = lencopy;
 200                 }
 201
 202                 /* Check if the copy is done */
 203                 if (lencopy == 0 || remain == 0)
 204                         return;
 205
 206                 if (lencopy < 0) {
 207                         printk_ratelimited(KERN_WARNING "stk1160: negative lencopy detected\n");
 208                         return;
 209                 }
 210
 211                 if ((unsigned long)dst + lencopy >
 212                         (unsigned long)buf->mem + buf->length) {
 213                         printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
 214                         return;
 215                 }
 216
 217                 memcpy(dst, src, lencopy);
 218                 remain -= lencopy;
 219
 220                 buf->bytesused += lencopy;
 221                 buf->pos += lencopy;
 222         }
 223 }
 224
 225 /*
 226  * Controls the isoc copy of each urb packet
 227  */
 228 static void stk1160_process_isoc(struct stk1160 *dev, struct urb *urb)
 229 {
 230         int i, len, status;
 231         u8 *p;
 232
 233         if (!dev) {
 234                 stk1160_warn("%s called with null device\n", __func__);
 235                 return;
 236         }
 237
 238         if (urb->status < 0) {
 239                 /* Print status and drop current packet (or field?) */
 240                 print_err_status(dev, -1, urb->status);
 241                 return;
 242         }
 243
 244         for (i = 0; i < urb->number_of_packets; i++) {
 245                 status = urb->iso_frame_desc[i].status;
 246                 if (status < 0) {
 247                         print_err_status(dev, i, status);
 248                         continue;
 249                 }
 250
 251                 /* Get packet actual length and pointer to data */
 252                 p = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
 253                 len = urb->iso_frame_desc[i].actual_length;
 254
 255                 /* Empty packet */
 256                 if (len <= 4)
 257                         continue;
 258
 259                 /*
 260                  * An 8-byte packet sequence means end of field.
 261                  * So if we don't have any packet, we start receiving one now
 262                  * and if we do have a packet, then we are done with it.
 263                  *
 264                  * These end of field packets are always 0xc0 or 0x80,
 265                  * but not always 8-byte long so we don't check packet length.
 266                  */
 267                 if (p[0] == 0xc0) {
 268
 269                         /*
 270                          * If first byte is 0xc0 then we received
 271                          * second field, and frame has ended.
 272                          */
 273                         if (dev->isoc_ctl.buf != NULL)
 274                                 stk1160_buffer_done(dev);
 275
 276                         dev->isoc_ctl.buf = stk1160_next_buffer(dev);
 277                         if (dev->isoc_ctl.buf == NULL)
 278                                 return;
 279                 }
 280
 281                 /*
 282                  * If we don't have a buffer here, then it means we
 283                  * haven't found the start mark sequence.
 284                  */
 285                 if (dev->isoc_ctl.buf == NULL)
 286                         continue;
 287
 288                 if (p[0] == 0xc0 || p[0] == 0x80) {
 289
 290                         /* We set next packet parity and
 291                          * continue to get next one
 292                          */
 293                         dev->isoc_ctl.buf->odd = *p & 0x40;
 294                         dev->isoc_ctl.buf->pos = 0;
 295                         continue;
 296                 }
 297
 298                 stk1160_copy_video(dev, p, len);
 299         }
 300 }
 301
 302
 303 /*
 304  * IRQ callback, called by URB callback
 305  */
 306 static void stk1160_isoc_irq(struct urb *urb)
 307 {
 308         int i, rc;
 309         struct stk1160 *dev = urb->context;
 310
 311         switch (urb->status) {
 312         case 0:
 313                 break;
 314         case -ECONNRESET:   /* kill */
 315         case -ENOENT:
 316         case -ESHUTDOWN:
 317                 /* TODO: check uvc driver: he frees the queue here */
 318                 return;
 319         default:
 320                 stk1160_err("urb error! status %d\n", urb->status);
 321                 return;
 322         }
 323
 324         stk1160_process_isoc(dev, urb);
 325
 326         /* Reset urb buffers */
 327         for (i = 0; i < urb->number_of_packets; i++) {
 328                 urb->iso_frame_desc[i].status = 0;
 329                 urb->iso_frame_desc[i].actual_length = 0;
 330         }
 331
 332         rc = usb_submit_urb(urb, GFP_ATOMIC);
 333         if (rc)
 334                 stk1160_err("urb re-submit failed (%d)\n", rc);
 335 }
 336
 337 /*
 338  * Cancel urbs
 339  * This function can't be called in atomic context
 340  */
 341 void stk1160_cancel_isoc(struct stk1160 *dev)
 342 {
 343         int i, num_bufs = dev->isoc_ctl.num_bufs;
 344
 345         /*
 346          * This check is not necessary, but we add it
 347          * to avoid a spurious debug message
 348          */
 349         if (!num_bufs)
 350                 return;
 351
 352         stk1160_dbg("killing %d urbs...\n", num_bufs);
 353
 354         for (i = 0; i < num_bufs; i++) {
 355
 356                 /*
 357                  * To kill urbs we can't be in atomic context.
 358                  * We don't care for NULL pointer since
 359                  * usb_kill_urb allows it.
 360                  */
 361                 usb_kill_urb(dev->isoc_ctl.urb[i]);
 362         }
 363
 364         stk1160_dbg("all urbs killed\n");
 365 }
 366
 367 /*
 368  * Releases urb and transfer buffers
 369  * Obviusly, associated urb must be killed before releasing it.
 370  */
 371 void stk1160_free_isoc(struct stk1160 *dev)
 372 {
 373         struct urb *urb;
 374         int i, num_bufs = dev->isoc_ctl.num_bufs;
 375
 376         stk1160_dbg("freeing %d urb buffers...\n", num_bufs);
 377
 378         for (i = 0; i < num_bufs; i++) {
 379
 380                 urb = dev->isoc_ctl.urb[i];
 381                 if (urb) {
 382
 383                         if (dev->isoc_ctl.transfer_buffer[i]) {
 384 #ifndef CONFIG_DMA_NONCOHERENT
 385                                 usb_free_coherent(dev->udev,
 386                                         urb->transfer_buffer_length,
 387                                         dev->isoc_ctl.transfer_buffer[i],
 388                                         urb->transfer_dma);
 389 #else
 390                                 kfree(dev->isoc_ctl.transfer_buffer[i]);
 391 #endif
 392                         }
 393                         usb_free_urb(urb);
 394                         dev->isoc_ctl.urb[i] = NULL;
 395                 }
 396                 dev->isoc_ctl.transfer_buffer[i] = NULL;
 397         }
 398
 399         kfree(dev->isoc_ctl.urb);
 400         kfree(dev->isoc_ctl.transfer_buffer);
 401
 402         dev->isoc_ctl.urb = NULL;
 403         dev->isoc_ctl.transfer_buffer = NULL;
 404         dev->isoc_ctl.num_bufs = 0;
 405
 406         stk1160_dbg("all urb buffers freed\n");
 407 }
 408
 409 /*
 410  * Helper for cancelling and freeing urbs
 411  * This function can't be called in atomic context
 412  */
 413 void stk1160_uninit_isoc(struct stk1160 *dev)
 414 {
 415         stk1160_cancel_isoc(dev);
 416         stk1160_free_isoc(dev);
 417 }
 418
 419 /*
 420  * Allocate URBs
 421  */
 422 int stk1160_alloc_isoc(struct stk1160 *dev)
 423 {
 424         struct urb *urb;
 425         int i, j, k, sb_size, max_packets, num_bufs;
 426
 427         /*
 428          * It may be necessary to release isoc here,
 429          * since isoc are only released on disconnection.
 430          * (see new_pkt_size flag)
 431          */
 432         if (dev->isoc_ctl.num_bufs)
 433                 stk1160_uninit_isoc(dev);
 434
 435         stk1160_dbg("allocating urbs...\n");
 436
 437         num_bufs = STK1160_NUM_BUFS;
 438         max_packets = STK1160_NUM_PACKETS;
 439         sb_size = max_packets * dev->max_pkt_size;
 440
 441         dev->isoc_ctl.buf = NULL;
 442         dev->isoc_ctl.max_pkt_size = dev->max_pkt_size;
 443         dev->isoc_ctl.urb = kzalloc(sizeof(void *)*num_bufs, GFP_KERNEL);
 444         if (!dev->isoc_ctl.urb) {
 445                 stk1160_err("out of memory for urb array\n");
 446                 return -ENOMEM;
 447         }
 448
 449         dev->isoc_ctl.transfer_buffer = kzalloc(sizeof(void *)*num_bufs,
 450                                               GFP_KERNEL);
 451         if (!dev->isoc_ctl.transfer_buffer) {
 452                 stk1160_err("out of memory for usb transfers\n");
 453                 kfree(dev->isoc_ctl.urb);
 454                 return -ENOMEM;
 455         }
 456
 457         /* allocate urbs and transfer buffers */
 458         for (i = 0; i < num_bufs; i++) {
 459
 460                 urb = usb_alloc_urb(max_packets, GFP_KERNEL);
 461                 if (!urb) {
 462                         stk1160_err("cannot alloc urb[%d]\n", i);
 463                         goto free_i_bufs;
 464                 }
 465                 dev->isoc_ctl.urb[i] = urb;
 466
 467 #ifndef CONFIG_DMA_NONCOHERENT
 468                 dev->isoc_ctl.transfer_buffer[i] = usb_alloc_coherent(dev->udev,
 469                         sb_size, GFP_KERNEL, &urb->transfer_dma);
 470 #else
 471                 dev->isoc_ctl.transfer_buffer[i] = kmalloc(sb_size, GFP_KERNEL);
 472 #endif
 473                 if (!dev->isoc_ctl.transfer_buffer[i]) {
 474                         stk1160_err("cannot alloc %d bytes for tx[%d] buffer\n",
 475                                 sb_size, i);
 476
 477                         /* Not enough transfer buffers, so just give up */
 478                         if (i < STK1160_MIN_BUFS)
 479                                 goto free_i_bufs;
 480                         goto nomore_tx_bufs;
 481                 }
 482                 memset(dev->isoc_ctl.transfer_buffer[i], 0, sb_size);
 483
 484                 /*
 485                  * FIXME: Where can I get the endpoint?
 486                  */
 487                 urb->dev = dev->udev;
 488                 urb->pipe = usb_rcvisocpipe(dev->udev, STK1160_EP_VIDEO);
 489                 urb->transfer_buffer = dev->isoc_ctl.transfer_buffer[i];
 490                 urb->transfer_buffer_length = sb_size;
 491                 urb->complete = stk1160_isoc_irq;
 492                 urb->context = dev;
 493                 urb->interval = 1;
 494                 urb->start_frame = 0;
 495                 urb->number_of_packets = max_packets;
 496 #ifndef CONFIG_DMA_NONCOHERENT
 497                 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
 498 #else
 499                 urb->transfer_flags = URB_ISO_ASAP;
 500 #endif
 501
 502                 k = 0;
 503                 for (j = 0; j < max_packets; j++) {
 504                         urb->iso_frame_desc[j].offset = k;
 505                         urb->iso_frame_desc[j].length =
 506                                         dev->isoc_ctl.max_pkt_size;
 507                         k += dev->isoc_ctl.max_pkt_size;
 508                 }
 509         }
 510
 511         stk1160_dbg("%d urbs allocated\n", num_bufs);
 512
 513         /* At last we can say we have some buffers */
 514         dev->isoc_ctl.num_bufs = num_bufs;
 515
 516         return 0;
 517
 518 nomore_tx_bufs:
 519         /*
 520          * Failed to allocate desired buffer count. However, we may have
 521          * enough to work fine, so we just free the extra urb,
 522          * store the allocated count and keep going, fingers crossed!
 523          */
 524         usb_free_urb(dev->isoc_ctl.urb[i]);
 525         dev->isoc_ctl.urb[i] = NULL;
 526
 527         stk1160_warn("%d urbs allocated. Trying to continue...\n", i - 1);
 528
 529         dev->isoc_ctl.num_bufs = i - 1;
 530
 531         return 0;
 532
 533 free_i_bufs:
 534         /* Save the allocated buffers so far, so we can properly free them */
 535         dev->isoc_ctl.num_bufs = i+1;
 536         stk1160_free_isoc(dev);
 537         return -ENOMEM;
 538 }
 539