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

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

DEFINITIONS
