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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * STK1160 driver
   4  *
   5  * Copyright (C) 2012 Ezequiel Garcia
   6  * <elezegarcia--a.t--gmail.com>
   7  *
   8  * Based on Easycap driver by R.M. Thomas
   9  *      Copyright (C) 2010 R.M. Thomas
  10  *      <rmthomas--a.t--sciolus.org>
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/usb.h>
  15 #include <linux/slab.h>
  16 #include <linux/ratelimit.h>
  17
  18 #include "stk1160.h"
  19
  20 static unsigned int debug;
  21 module_param(debug, int, 0644);
  22 MODULE_PARM_DESC(debug, "enable debug messages");
  23
  24 static inline void print_err_status(struct stk1160 *dev,
  25                                      int packet, int status)
  26 {
  27         char *errmsg = "Unknown";
  28
  29         switch (status) {
  30         case -ENOENT:
  31                 errmsg = "unlinked synchronously";
  32                 break;
  33         case -ECONNRESET:
  34                 errmsg = "unlinked asynchronously";
  35                 break;
  36         case -ENOSR:
  37                 errmsg = "Buffer error (overrun)";
  38                 break;
  39         case -EPIPE:
  40                 errmsg = "Stalled (device not responding)";
  41                 break;
  42         case -EOVERFLOW:
  43                 errmsg = "Babble (bad cable?)";
  44                 break;
  45         case -EPROTO:
  46                 errmsg = "Bit-stuff error (bad cable?)";
  47                 break;
  48         case -EILSEQ:
  49                 errmsg = "CRC/Timeout (could be anything)";
  50                 break;
  51         case -ETIME:
  52                 errmsg = "Device does not respond";
  53                 break;
  54         }
  55
  56         if (packet < 0)
  57                 printk_ratelimited(KERN_WARNING "URB status %d [%s].\n",
  58                                 status, errmsg);
  59         else
  60                 printk_ratelimited(KERN_INFO "URB packet %d, status %d [%s].\n",
  61                                packet, status, errmsg);
  62 }
  63
  64 static inline
  65 struct stk1160_buffer *stk1160_next_buffer(struct stk1160 *dev)
  66 {
  67         struct stk1160_buffer *buf = NULL;
  68         unsigned long flags = 0;
  69
  70         /* Current buffer must be NULL when this functions gets called */
  71         WARN_ON(dev->isoc_ctl.buf);
  72
  73         spin_lock_irqsave(&dev->buf_lock, flags);
  74         if (!list_empty(&dev->avail_bufs)) {
  75                 buf = list_first_entry(&dev->avail_bufs,
  76                                 struct stk1160_buffer, list);
  77                 list_del(&buf->list);
  78         }
  79         spin_unlock_irqrestore(&dev->buf_lock, flags);
  80
  81         return buf;
  82 }
  83
  84 static inline
  85 void stk1160_buffer_done(struct stk1160 *dev)
  86 {
  87         struct stk1160_buffer *buf = dev->isoc_ctl.buf;
  88
  89         buf->vb.sequence = dev->sequence++;
  90         buf->vb.field = V4L2_FIELD_INTERLACED;
  91         buf->vb.vb2_buf.timestamp = ktime_get_ns();
  92
  93         vb2_set_plane_payload(&buf->vb.vb2_buf, 0, buf->bytesused);
  94         vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
  95
  96         dev->isoc_ctl.buf = NULL;
  97 }
  98
  99 static inline
 100 void stk1160_copy_video(struct stk1160 *dev, u8 *src, int len)
 101 {
 102         int linesdone, lineoff, lencopy;
 103         int bytesperline = dev->width * 2;
 104         struct stk1160_buffer *buf = dev->isoc_ctl.buf;
 105         u8 *dst = buf->mem;
 106         int remain;
 107
 108         /*
 109          * TODO: These stk1160_dbg are very spammy!
 110          * We should check why we are getting them.
 111          *
 112          * UPDATE: One of the reasons (the only one?) for getting these
 113          * is incorrect standard (mismatch between expected and configured).
 114          * So perhaps, we could add a counter for errors. When the counter
 115          * reaches some value, we simply stop streaming.
 116          */
 117
 118         len -= 4;
 119         src += 4;
 120
 121         remain = len;
 122
 123         linesdone = buf->pos / bytesperline;
 124         lineoff = buf->pos % bytesperline; /* offset in current line */
 125
 126         if (!buf->odd)
 127                 dst += bytesperline;
 128
 129         /* Multiply linesdone by two, to take account of the other field */
 130         dst += linesdone * bytesperline * 2 + lineoff;
 131
 132         /* Copy the remaining of current line */
 133         if (remain < (bytesperline - lineoff))
 134                 lencopy = remain;
 135         else
 136                 lencopy = bytesperline - lineoff;
 137
 138         /*
 139          * Check if we have enough space left in the buffer.
 140          * In that case, we force loop exit after copy.
 141          */
 142         if (lencopy > buf->bytesused - buf->length) {
 143                 lencopy = buf->bytesused - buf->length;
 144                 remain = lencopy;
 145         }
 146
 147         /* Check if the copy is done */
 148         if (lencopy == 0 || remain == 0)
 149                 return;
 150
 151         /* Let the bug hunt begin! sanity checks! */
 152         if (lencopy < 0) {
 153                 printk_ratelimited(KERN_DEBUG "copy skipped: negative lencopy\n");
 154                 return;
 155         }
 156
 157         if ((unsigned long)dst + lencopy >
 158                 (unsigned long)buf->mem + buf->length) {
 159                 printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
 160                 return;
 161         }
 162
 163         memcpy(dst, src, lencopy);
 164
 165         buf->bytesused += lencopy;
 166         buf->pos += lencopy;
 167         remain -= lencopy;
 168
 169         /* Copy current field line by line, interlacing with the other field */
 170         while (remain > 0) {
 171
 172                 dst += lencopy + bytesperline;
 173                 src += lencopy;
 174
 175                 /* Copy one line at a time */
 176                 if (remain < bytesperline)
 177                         lencopy = remain;
 178                 else
 179                         lencopy = bytesperline;
 180
 181                 /*
 182                  * Check if we have enough space left in the buffer.
 183                  * In that case, we force loop exit after copy.
 184                  */
 185                 if (lencopy > buf->bytesused - buf->length) {
 186                         lencopy = buf->bytesused - buf->length;
 187                         remain = lencopy;
 188                 }
 189
 190                 /* Check if the copy is done */
 191                 if (lencopy == 0 || remain == 0)
 192                         return;
 193
 194                 if (lencopy < 0) {
 195                         printk_ratelimited(KERN_WARNING "stk1160: negative lencopy detected\n");
 196                         return;
 197                 }
 198
 199                 if ((unsigned long)dst + lencopy >
 200                         (unsigned long)buf->mem + buf->length) {
 201                         printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
 202                         return;
 203                 }
 204
 205                 memcpy(dst, src, lencopy);
 206                 remain -= lencopy;
 207
 208                 buf->bytesused += lencopy;
 209                 buf->pos += lencopy;
 210         }
 211 }
 212
 213 /*
 214  * Controls the isoc copy of each urb packet
 215  */
 216 static void stk1160_process_isoc(struct stk1160 *dev, struct urb *urb)
 217 {
 218         int i, len, status;
 219         u8 *p;
 220
 221         if (!dev) {
 222                 stk1160_warn("%s called with null device\n", __func__);
 223                 return;
 224         }
 225
 226         if (urb->status < 0) {
 227                 /* Print status and drop current packet (or field?) */
 228                 print_err_status(dev, -1, urb->status);
 229                 return;
 230         }
 231
 232         for (i = 0; i < urb->number_of_packets; i++) {
 233                 status = urb->iso_frame_desc[i].status;
 234                 if (status < 0) {
 235                         print_err_status(dev, i, status);
 236                         continue;
 237                 }
 238
 239                 /* Get packet actual length and pointer to data */
 240                 p = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
 241                 len = urb->iso_frame_desc[i].actual_length;
 242
 243                 /* Empty packet */
 244                 if (len <= 4)
 245                         continue;
 246
 247                 /*
 248                  * An 8-byte packet sequence means end of field.
 249                  * So if we don't have any packet, we start receiving one now
 250                  * and if we do have a packet, then we are done with it.
 251                  *
 252                  * These end of field packets are always 0xc0 or 0x80,
 253                  * but not always 8-byte long so we don't check packet length.
 254                  */
 255                 if (p[0] == 0xc0) {
 256
 257                         /*
 258                          * If first byte is 0xc0 then we received
 259                          * second field, and frame has ended.
 260                          */
 261                         if (dev->isoc_ctl.buf != NULL)
 262                                 stk1160_buffer_done(dev);
 263
 264                         dev->isoc_ctl.buf = stk1160_next_buffer(dev);
 265                         if (dev->isoc_ctl.buf == NULL)
 266                                 return;
 267                 }
 268
 269                 /*
 270                  * If we don't have a buffer here, then it means we
 271                  * haven't found the start mark sequence.
 272                  */
 273                 if (dev->isoc_ctl.buf == NULL)
 274                         continue;
 275
 276                 if (p[0] == 0xc0 || p[0] == 0x80) {
 277
 278                         /* We set next packet parity and
 279                          * continue to get next one
 280                          */
 281                         dev->isoc_ctl.buf->odd = *p & 0x40;
 282                         dev->isoc_ctl.buf->pos = 0;
 283                         continue;
 284                 }
 285
 286                 stk1160_copy_video(dev, p, len);
 287         }
 288 }
 289
 290
 291 /*
 292  * IRQ callback, called by URB callback
 293  */
 294 static void stk1160_isoc_irq(struct urb *urb)
 295 {
 296         int i, rc;
 297         struct stk1160_urb *stk_urb = urb->context;
 298         struct stk1160 *dev = stk_urb->dev;
 299         struct device *dma_dev = stk1160_get_dmadev(dev);
 300
 301         switch (urb->status) {
 302         case 0:
 303                 break;
 304         case -ECONNRESET:   /* kill */
 305         case -ENOENT:
 306         case -ESHUTDOWN:
 307                 /* TODO: check uvc driver: he frees the queue here */
 308                 return;
 309         default:
 310                 stk1160_err("urb error! status %d\n", urb->status);
 311                 return;
 312         }
 313
 314         invalidate_kernel_vmap_range(stk_urb->transfer_buffer,
 315                                      urb->transfer_buffer_length);
 316         dma_sync_sgtable_for_cpu(dma_dev, stk_urb->sgt, DMA_FROM_DEVICE);
 317
 318         stk1160_process_isoc(dev, urb);
 319
 320         /* Reset urb buffers */
 321         for (i = 0; i < urb->number_of_packets; i++) {
 322                 urb->iso_frame_desc[i].status = 0;
 323                 urb->iso_frame_desc[i].actual_length = 0;
 324         }
 325
 326         dma_sync_sgtable_for_device(dma_dev, stk_urb->sgt, DMA_FROM_DEVICE);
 327         rc = usb_submit_urb(urb, GFP_ATOMIC);
 328         if (rc)
 329                 stk1160_err("urb re-submit failed (%d)\n", rc);
 330 }
 331
 332 /*
 333  * Cancel urbs
 334  * This function can't be called in atomic context
 335  */
 336 void stk1160_cancel_isoc(struct stk1160 *dev)
 337 {
 338         int i, num_bufs = dev->isoc_ctl.num_bufs;
 339
 340         /*
 341          * This check is not necessary, but we add it
 342          * to avoid a spurious debug message
 343          */
 344         if (!num_bufs)
 345                 return;
 346
 347         stk1160_dbg("killing %d urbs...\n", num_bufs);
 348
 349         for (i = 0; i < num_bufs; i++) {
 350
 351                 /*
 352                  * To kill urbs we can't be in atomic context.
 353                  * We don't care for NULL pointer since
 354                  * usb_kill_urb allows it.
 355                  */
 356                 usb_kill_urb(dev->isoc_ctl.urb_ctl[i].urb);
 357         }
 358
 359         stk1160_dbg("all urbs killed\n");
 360 }
 361
 362 static void stk_free_urb(struct stk1160 *dev, struct stk1160_urb *stk_urb)
 363 {
 364         struct device *dma_dev = stk1160_get_dmadev(dev);
 365
 366         dma_vunmap_noncontiguous(dma_dev, stk_urb->transfer_buffer);
 367         dma_free_noncontiguous(dma_dev, stk_urb->urb->transfer_buffer_length,
 368                                stk_urb->sgt, DMA_FROM_DEVICE);
 369         usb_free_urb(stk_urb->urb);
 370
 371         stk_urb->transfer_buffer = NULL;
 372         stk_urb->sgt = NULL;
 373         stk_urb->urb = NULL;
 374         stk_urb->dev = NULL;
 375         stk_urb->dma = 0;
 376 }
 377
 378 /*
 379  * Releases urb and transfer buffers
 380  * Obviusly, associated urb must be killed before releasing it.
 381  */
 382 void stk1160_free_isoc(struct stk1160 *dev)
 383 {
 384         int i, num_bufs = dev->isoc_ctl.num_bufs;
 385
 386         stk1160_dbg("freeing %d urb buffers...\n", num_bufs);
 387
 388         for (i = 0; i < num_bufs; i++)
 389                 stk_free_urb(dev, &dev->isoc_ctl.urb_ctl[i]);
 390
 391         dev->isoc_ctl.num_bufs = 0;
 392
 393         stk1160_dbg("all urb buffers freed\n");
 394 }
 395
 396 /*
 397  * Helper for cancelling and freeing urbs
 398  * This function can't be called in atomic context
 399  */
 400 void stk1160_uninit_isoc(struct stk1160 *dev)
 401 {
 402         stk1160_cancel_isoc(dev);
 403         stk1160_free_isoc(dev);
 404 }
 405
 406 static int stk1160_fill_urb(struct stk1160 *dev, struct stk1160_urb *stk_urb,
 407                             int sb_size, int max_packets)
 408 {
 409         struct device *dma_dev = stk1160_get_dmadev(dev);
 410
 411         stk_urb->urb = usb_alloc_urb(max_packets, GFP_KERNEL);
 412         if (!stk_urb->urb)
 413                 return -ENOMEM;
 414         stk_urb->sgt = dma_alloc_noncontiguous(dma_dev, sb_size,
 415                                                DMA_FROM_DEVICE, GFP_KERNEL, 0);
 416
 417         /*
 418          * If the buffer allocation failed, we exit but return 0 since
 419          * we allow the driver working with less buffers
 420          */
 421         if (!stk_urb->sgt)
 422                 goto free_urb;
 423
 424         stk_urb->transfer_buffer = dma_vmap_noncontiguous(dma_dev, sb_size,
 425                                                           stk_urb->sgt);
 426         if (!stk_urb->transfer_buffer)
 427                 goto free_sgt;
 428
 429         stk_urb->dma = stk_urb->sgt->sgl->dma_address;
 430         stk_urb->dev = dev;
 431         return 0;
 432 free_sgt:
 433         dma_free_noncontiguous(dma_dev, sb_size, stk_urb->sgt, DMA_FROM_DEVICE);
 434         stk_urb->sgt = NULL;
 435 free_urb:
 436         usb_free_urb(stk_urb->urb);
 437         stk_urb->urb = NULL;
 438
 439         return 0;
 440 }
 441 /*
 442  * Allocate URBs
 443  */
 444 int stk1160_alloc_isoc(struct stk1160 *dev)
 445 {
 446         struct urb *urb;
 447         int i, j, k, sb_size, max_packets, num_bufs;
 448         int ret;
 449
 450         /*
 451          * It may be necessary to release isoc here,
 452          * since isoc are only released on disconnection.
 453          * (see new_pkt_size flag)
 454          */
 455         if (dev->isoc_ctl.num_bufs)
 456                 stk1160_uninit_isoc(dev);
 457
 458         stk1160_dbg("allocating urbs...\n");
 459
 460         num_bufs = STK1160_NUM_BUFS;
 461         max_packets = STK1160_NUM_PACKETS;
 462         sb_size = max_packets * dev->max_pkt_size;
 463
 464         dev->isoc_ctl.buf = NULL;
 465         dev->isoc_ctl.max_pkt_size = dev->max_pkt_size;
 466
 467         /* allocate urbs and transfer buffers */
 468         for (i = 0; i < num_bufs; i++) {
 469
 470                 ret = stk1160_fill_urb(dev, &dev->isoc_ctl.urb_ctl[i],
 471                                        sb_size, max_packets);
 472                 if (ret)
 473                         goto free_i_bufs;
 474
 475                 urb = dev->isoc_ctl.urb_ctl[i].urb;
 476
 477                 if (!urb) {
 478                         /* Not enough transfer buffers, so just give up */
 479                         if (i < STK1160_MIN_BUFS)
 480                                 goto free_i_bufs;
 481                         goto nomore_tx_bufs;
 482                 }
 483                 memset(dev->isoc_ctl.urb_ctl[i].transfer_buffer, 0, sb_size);
 484
 485                 /*
 486                  * FIXME: Where can I get the endpoint?
 487                  */
 488                 urb->dev = dev->udev;
 489                 urb->pipe = usb_rcvisocpipe(dev->udev, STK1160_EP_VIDEO);
 490                 urb->transfer_buffer = dev->isoc_ctl.urb_ctl[i].transfer_buffer;
 491                 urb->transfer_buffer_length = sb_size;
 492                 urb->complete = stk1160_isoc_irq;
 493                 urb->context = &dev->isoc_ctl.urb_ctl[i];
 494                 urb->interval = 1;
 495                 urb->start_frame = 0;
 496                 urb->number_of_packets = max_packets;
 497                 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
 498                 urb->transfer_dma = dev->isoc_ctl.urb_ctl[i].dma;
 499
 500                 k = 0;
 501                 for (j = 0; j < max_packets; j++) {
 502                         urb->iso_frame_desc[j].offset = k;
 503                         urb->iso_frame_desc[j].length =
 504                                         dev->isoc_ctl.max_pkt_size;
 505                         k += dev->isoc_ctl.max_pkt_size;
 506                 }
 507         }
 508
 509         stk1160_dbg("%d urbs allocated\n", num_bufs);
 510
 511         /* At last we can say we have some buffers */
 512         dev->isoc_ctl.num_bufs = num_bufs;
 513
 514         return 0;
 515
 516 nomore_tx_bufs:
 517         /*
 518          * Failed to allocate desired buffer count. However, we may have
 519          * enough to work fine, so we just free the extra urb,
 520          * store the allocated count and keep going, fingers crossed!
 521          */
 522
 523         stk1160_warn("%d urbs allocated. Trying to continue...\n", i);
 524
 525         dev->isoc_ctl.num_bufs = i;
 526
 527         return 0;
 528
 529 free_i_bufs:
 530         /* Save the allocated buffers so far, so we can properly free them */
 531         dev->isoc_ctl.num_bufs = i;
 532         stk1160_free_isoc(dev);
 533         return -ENOMEM;
 534 }
 535