linux/drivers/media/video/uvc/uvc_video.c
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   1/*
   2 *      uvc_video.c  --  USB Video Class driver - Video handling
   3 *
   4 *      Copyright (C) 2005-2009
   5 *          Laurent Pinchart (laurent.pinchart@skynet.be)
   6 *
   7 *      This program is free software; you can redistribute it and/or modify
   8 *      it under the terms of the GNU General Public License as published by
   9 *      the Free Software Foundation; either version 2 of the License, or
  10 *      (at your option) any later version.
  11 *
  12 */
  13
  14#include <linux/kernel.h>
  15#include <linux/list.h>
  16#include <linux/module.h>
  17#include <linux/slab.h>
  18#include <linux/usb.h>
  19#include <linux/videodev2.h>
  20#include <linux/vmalloc.h>
  21#include <linux/wait.h>
  22#include <asm/atomic.h>
  23#include <asm/unaligned.h>
  24
  25#include <media/v4l2-common.h>
  26
  27#include "uvcvideo.h"
  28
  29/* ------------------------------------------------------------------------
  30 * UVC Controls
  31 */
  32
  33static int __uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
  34                        __u8 intfnum, __u8 cs, void *data, __u16 size,
  35                        int timeout)
  36{
  37        __u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
  38        unsigned int pipe;
  39
  40        pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0)
  41                              : usb_sndctrlpipe(dev->udev, 0);
  42        type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
  43
  44        return usb_control_msg(dev->udev, pipe, query, type, cs << 8,
  45                        unit << 8 | intfnum, data, size, timeout);
  46}
  47
  48int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
  49                        __u8 intfnum, __u8 cs, void *data, __u16 size)
  50{
  51        int ret;
  52
  53        ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size,
  54                                UVC_CTRL_CONTROL_TIMEOUT);
  55        if (ret != size) {
  56                uvc_printk(KERN_ERR, "Failed to query (%u) UVC control %u "
  57                        "(unit %u) : %d (exp. %u).\n", query, cs, unit, ret,
  58                        size);
  59                return -EIO;
  60        }
  61
  62        return 0;
  63}
  64
  65static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
  66        struct uvc_streaming_control *ctrl)
  67{
  68        struct uvc_format *format;
  69        struct uvc_frame *frame = NULL;
  70        unsigned int i;
  71
  72        if (ctrl->bFormatIndex <= 0 ||
  73            ctrl->bFormatIndex > stream->nformats)
  74                return;
  75
  76        format = &stream->format[ctrl->bFormatIndex - 1];
  77
  78        for (i = 0; i < format->nframes; ++i) {
  79                if (format->frame[i].bFrameIndex == ctrl->bFrameIndex) {
  80                        frame = &format->frame[i];
  81                        break;
  82                }
  83        }
  84
  85        if (frame == NULL)
  86                return;
  87
  88        if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) ||
  89             (ctrl->dwMaxVideoFrameSize == 0 &&
  90              stream->dev->uvc_version < 0x0110))
  91                ctrl->dwMaxVideoFrameSize =
  92                        frame->dwMaxVideoFrameBufferSize;
  93
  94        if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) &&
  95            stream->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH &&
  96            stream->intf->num_altsetting > 1) {
  97                u32 interval;
  98                u32 bandwidth;
  99
 100                interval = (ctrl->dwFrameInterval > 100000)
 101                         ? ctrl->dwFrameInterval
 102                         : frame->dwFrameInterval[0];
 103
 104                /* Compute a bandwidth estimation by multiplying the frame
 105                 * size by the number of video frames per second, divide the
 106                 * result by the number of USB frames (or micro-frames for
 107                 * high-speed devices) per second and add the UVC header size
 108                 * (assumed to be 12 bytes long).
 109                 */
 110                bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp;
 111                bandwidth *= 10000000 / interval + 1;
 112                bandwidth /= 1000;
 113                if (stream->dev->udev->speed == USB_SPEED_HIGH)
 114                        bandwidth /= 8;
 115                bandwidth += 12;
 116
 117                ctrl->dwMaxPayloadTransferSize = bandwidth;
 118        }
 119}
 120
 121static int uvc_get_video_ctrl(struct uvc_streaming *stream,
 122        struct uvc_streaming_control *ctrl, int probe, __u8 query)
 123{
 124        __u8 *data;
 125        __u16 size;
 126        int ret;
 127
 128        size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
 129        if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) &&
 130                        query == UVC_GET_DEF)
 131                return -EIO;
 132
 133        data = kmalloc(size, GFP_KERNEL);
 134        if (data == NULL)
 135                return -ENOMEM;
 136
 137        ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
 138                probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
 139                size, uvc_timeout_param);
 140
 141        if ((query == UVC_GET_MIN || query == UVC_GET_MAX) && ret == 2) {
 142                /* Some cameras, mostly based on Bison Electronics chipsets,
 143                 * answer a GET_MIN or GET_MAX request with the wCompQuality
 144                 * field only.
 145                 */
 146                uvc_warn_once(stream->dev, UVC_WARN_MINMAX, "UVC non "
 147                        "compliance - GET_MIN/MAX(PROBE) incorrectly "
 148                        "supported. Enabling workaround.\n");
 149                memset(ctrl, 0, sizeof *ctrl);
 150                ctrl->wCompQuality = le16_to_cpup((__le16 *)data);
 151                ret = 0;
 152                goto out;
 153        } else if (query == UVC_GET_DEF && probe == 1 && ret != size) {
 154                /* Many cameras don't support the GET_DEF request on their
 155                 * video probe control. Warn once and return, the caller will
 156                 * fall back to GET_CUR.
 157                 */
 158                uvc_warn_once(stream->dev, UVC_WARN_PROBE_DEF, "UVC non "
 159                        "compliance - GET_DEF(PROBE) not supported. "
 160                        "Enabling workaround.\n");
 161                ret = -EIO;
 162                goto out;
 163        } else if (ret != size) {
 164                uvc_printk(KERN_ERR, "Failed to query (%u) UVC %s control : "
 165                        "%d (exp. %u).\n", query, probe ? "probe" : "commit",
 166                        ret, size);
 167                ret = -EIO;
 168                goto out;
 169        }
 170
 171        ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]);
 172        ctrl->bFormatIndex = data[2];
 173        ctrl->bFrameIndex = data[3];
 174        ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]);
 175        ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]);
 176        ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]);
 177        ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]);
 178        ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]);
 179        ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]);
 180        ctrl->dwMaxVideoFrameSize = get_unaligned_le32(&data[18]);
 181        ctrl->dwMaxPayloadTransferSize = get_unaligned_le32(&data[22]);
 182
 183        if (size == 34) {
 184                ctrl->dwClockFrequency = get_unaligned_le32(&data[26]);
 185                ctrl->bmFramingInfo = data[30];
 186                ctrl->bPreferedVersion = data[31];
 187                ctrl->bMinVersion = data[32];
 188                ctrl->bMaxVersion = data[33];
 189        } else {
 190                ctrl->dwClockFrequency = stream->dev->clock_frequency;
 191                ctrl->bmFramingInfo = 0;
 192                ctrl->bPreferedVersion = 0;
 193                ctrl->bMinVersion = 0;
 194                ctrl->bMaxVersion = 0;
 195        }
 196
 197        /* Some broken devices return null or wrong dwMaxVideoFrameSize and
 198         * dwMaxPayloadTransferSize fields. Try to get the value from the
 199         * format and frame descriptors.
 200         */
 201        uvc_fixup_video_ctrl(stream, ctrl);
 202        ret = 0;
 203
 204out:
 205        kfree(data);
 206        return ret;
 207}
 208
 209static int uvc_set_video_ctrl(struct uvc_streaming *stream,
 210        struct uvc_streaming_control *ctrl, int probe)
 211{
 212        __u8 *data;
 213        __u16 size;
 214        int ret;
 215
 216        size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
 217        data = kzalloc(size, GFP_KERNEL);
 218        if (data == NULL)
 219                return -ENOMEM;
 220
 221        *(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint);
 222        data[2] = ctrl->bFormatIndex;
 223        data[3] = ctrl->bFrameIndex;
 224        *(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval);
 225        *(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate);
 226        *(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate);
 227        *(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality);
 228        *(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize);
 229        *(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay);
 230        put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]);
 231        put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]);
 232
 233        if (size == 34) {
 234                put_unaligned_le32(ctrl->dwClockFrequency, &data[26]);
 235                data[30] = ctrl->bmFramingInfo;
 236                data[31] = ctrl->bPreferedVersion;
 237                data[32] = ctrl->bMinVersion;
 238                data[33] = ctrl->bMaxVersion;
 239        }
 240
 241        ret = __uvc_query_ctrl(stream->dev, UVC_SET_CUR, 0, stream->intfnum,
 242                probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
 243                size, uvc_timeout_param);
 244        if (ret != size) {
 245                uvc_printk(KERN_ERR, "Failed to set UVC %s control : "
 246                        "%d (exp. %u).\n", probe ? "probe" : "commit",
 247                        ret, size);
 248                ret = -EIO;
 249        }
 250
 251        kfree(data);
 252        return ret;
 253}
 254
 255int uvc_probe_video(struct uvc_streaming *stream,
 256        struct uvc_streaming_control *probe)
 257{
 258        struct uvc_streaming_control probe_min, probe_max;
 259        __u16 bandwidth;
 260        unsigned int i;
 261        int ret;
 262
 263        mutex_lock(&stream->mutex);
 264
 265        /* Perform probing. The device should adjust the requested values
 266         * according to its capabilities. However, some devices, namely the
 267         * first generation UVC Logitech webcams, don't implement the Video
 268         * Probe control properly, and just return the needed bandwidth. For
 269         * that reason, if the needed bandwidth exceeds the maximum available
 270         * bandwidth, try to lower the quality.
 271         */
 272        ret = uvc_set_video_ctrl(stream, probe, 1);
 273        if (ret < 0)
 274                goto done;
 275
 276        /* Get the minimum and maximum values for compression settings. */
 277        if (!(stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX)) {
 278                ret = uvc_get_video_ctrl(stream, &probe_min, 1, UVC_GET_MIN);
 279                if (ret < 0)
 280                        goto done;
 281                ret = uvc_get_video_ctrl(stream, &probe_max, 1, UVC_GET_MAX);
 282                if (ret < 0)
 283                        goto done;
 284
 285                probe->wCompQuality = probe_max.wCompQuality;
 286        }
 287
 288        for (i = 0; i < 2; ++i) {
 289                ret = uvc_set_video_ctrl(stream, probe, 1);
 290                if (ret < 0)
 291                        goto done;
 292                ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);
 293                if (ret < 0)
 294                        goto done;
 295
 296                if (stream->intf->num_altsetting == 1)
 297                        break;
 298
 299                bandwidth = probe->dwMaxPayloadTransferSize;
 300                if (bandwidth <= stream->maxpsize)
 301                        break;
 302
 303                if (stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX) {
 304                        ret = -ENOSPC;
 305                        goto done;
 306                }
 307
 308                /* TODO: negotiate compression parameters */
 309                probe->wKeyFrameRate = probe_min.wKeyFrameRate;
 310                probe->wPFrameRate = probe_min.wPFrameRate;
 311                probe->wCompQuality = probe_max.wCompQuality;
 312                probe->wCompWindowSize = probe_min.wCompWindowSize;
 313        }
 314
 315done:
 316        mutex_unlock(&stream->mutex);
 317        return ret;
 318}
 319
 320int uvc_commit_video(struct uvc_streaming *stream,
 321        struct uvc_streaming_control *probe)
 322{
 323        return uvc_set_video_ctrl(stream, probe, 0);
 324}
 325
 326/* ------------------------------------------------------------------------
 327 * Video codecs
 328 */
 329
 330/* Values for bmHeaderInfo (Video and Still Image Payload Headers, 2.4.3.3) */
 331#define UVC_STREAM_EOH  (1 << 7)
 332#define UVC_STREAM_ERR  (1 << 6)
 333#define UVC_STREAM_STI  (1 << 5)
 334#define UVC_STREAM_RES  (1 << 4)
 335#define UVC_STREAM_SCR  (1 << 3)
 336#define UVC_STREAM_PTS  (1 << 2)
 337#define UVC_STREAM_EOF  (1 << 1)
 338#define UVC_STREAM_FID  (1 << 0)
 339
 340/* Video payload decoding is handled by uvc_video_decode_start(),
 341 * uvc_video_decode_data() and uvc_video_decode_end().
 342 *
 343 * uvc_video_decode_start is called with URB data at the start of a bulk or
 344 * isochronous payload. It processes header data and returns the header size
 345 * in bytes if successful. If an error occurs, it returns a negative error
 346 * code. The following error codes have special meanings.
 347 *
 348 * - EAGAIN informs the caller that the current video buffer should be marked
 349 *   as done, and that the function should be called again with the same data
 350 *   and a new video buffer. This is used when end of frame conditions can be
 351 *   reliably detected at the beginning of the next frame only.
 352 *
 353 * If an error other than -EAGAIN is returned, the caller will drop the current
 354 * payload. No call to uvc_video_decode_data and uvc_video_decode_end will be
 355 * made until the next payload. -ENODATA can be used to drop the current
 356 * payload if no other error code is appropriate.
 357 *
 358 * uvc_video_decode_data is called for every URB with URB data. It copies the
 359 * data to the video buffer.
 360 *
 361 * uvc_video_decode_end is called with header data at the end of a bulk or
 362 * isochronous payload. It performs any additional header data processing and
 363 * returns 0 or a negative error code if an error occured. As header data have
 364 * already been processed by uvc_video_decode_start, this functions isn't
 365 * required to perform sanity checks a second time.
 366 *
 367 * For isochronous transfers where a payload is always transfered in a single
 368 * URB, the three functions will be called in a row.
 369 *
 370 * To let the decoder process header data and update its internal state even
 371 * when no video buffer is available, uvc_video_decode_start must be prepared
 372 * to be called with a NULL buf parameter. uvc_video_decode_data and
 373 * uvc_video_decode_end will never be called with a NULL buffer.
 374 */
 375static int uvc_video_decode_start(struct uvc_streaming *stream,
 376                struct uvc_buffer *buf, const __u8 *data, int len)
 377{
 378        __u8 fid;
 379
 380        /* Sanity checks:
 381         * - packet must be at least 2 bytes long
 382         * - bHeaderLength value must be at least 2 bytes (see above)
 383         * - bHeaderLength value can't be larger than the packet size.
 384         */
 385        if (len < 2 || data[0] < 2 || data[0] > len)
 386                return -EINVAL;
 387
 388        /* Skip payloads marked with the error bit ("error frames"). */
 389        if (data[1] & UVC_STREAM_ERR) {
 390                uvc_trace(UVC_TRACE_FRAME, "Dropping payload (error bit "
 391                          "set).\n");
 392                return -ENODATA;
 393        }
 394
 395        fid = data[1] & UVC_STREAM_FID;
 396
 397        /* Store the payload FID bit and return immediately when the buffer is
 398         * NULL.
 399         */
 400        if (buf == NULL) {
 401                stream->last_fid = fid;
 402                return -ENODATA;
 403        }
 404
 405        /* Synchronize to the input stream by waiting for the FID bit to be
 406         * toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE.
 407         * stream->last_fid is initialized to -1, so the first isochronous
 408         * frame will always be in sync.
 409         *
 410         * If the device doesn't toggle the FID bit, invert stream->last_fid
 411         * when the EOF bit is set to force synchronisation on the next packet.
 412         */
 413        if (buf->state != UVC_BUF_STATE_ACTIVE) {
 414                struct timespec ts;
 415
 416                if (fid == stream->last_fid) {
 417                        uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of "
 418                                "sync).\n");
 419                        if ((stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID) &&
 420                            (data[1] & UVC_STREAM_EOF))
 421                                stream->last_fid ^= UVC_STREAM_FID;
 422                        return -ENODATA;
 423                }
 424
 425                if (uvc_clock_param == CLOCK_MONOTONIC)
 426                        ktime_get_ts(&ts);
 427                else
 428                        ktime_get_real_ts(&ts);
 429
 430                buf->buf.timestamp.tv_sec = ts.tv_sec;
 431                buf->buf.timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
 432
 433                /* TODO: Handle PTS and SCR. */
 434                buf->state = UVC_BUF_STATE_ACTIVE;
 435        }
 436
 437        /* Mark the buffer as done if we're at the beginning of a new frame.
 438         * End of frame detection is better implemented by checking the EOF
 439         * bit (FID bit toggling is delayed by one frame compared to the EOF
 440         * bit), but some devices don't set the bit at end of frame (and the
 441         * last payload can be lost anyway). We thus must check if the FID has
 442         * been toggled.
 443         *
 444         * stream->last_fid is initialized to -1, so the first isochronous
 445         * frame will never trigger an end of frame detection.
 446         *
 447         * Empty buffers (bytesused == 0) don't trigger end of frame detection
 448         * as it doesn't make sense to return an empty buffer. This also
 449         * avoids detecting end of frame conditions at FID toggling if the
 450         * previous payload had the EOF bit set.
 451         */
 452        if (fid != stream->last_fid && buf->buf.bytesused != 0) {
 453                uvc_trace(UVC_TRACE_FRAME, "Frame complete (FID bit "
 454                                "toggled).\n");
 455                buf->state = UVC_BUF_STATE_READY;
 456                return -EAGAIN;
 457        }
 458
 459        stream->last_fid = fid;
 460
 461        return data[0];
 462}
 463
 464static void uvc_video_decode_data(struct uvc_streaming *stream,
 465                struct uvc_buffer *buf, const __u8 *data, int len)
 466{
 467        struct uvc_video_queue *queue = &stream->queue;
 468        unsigned int maxlen, nbytes;
 469        void *mem;
 470
 471        if (len <= 0)
 472                return;
 473
 474        /* Copy the video data to the buffer. */
 475        maxlen = buf->buf.length - buf->buf.bytesused;
 476        mem = queue->mem + buf->buf.m.offset + buf->buf.bytesused;
 477        nbytes = min((unsigned int)len, maxlen);
 478        memcpy(mem, data, nbytes);
 479        buf->buf.bytesused += nbytes;
 480
 481        /* Complete the current frame if the buffer size was exceeded. */
 482        if (len > maxlen) {
 483                uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n");
 484                buf->state = UVC_BUF_STATE_READY;
 485        }
 486}
 487
 488static void uvc_video_decode_end(struct uvc_streaming *stream,
 489                struct uvc_buffer *buf, const __u8 *data, int len)
 490{
 491        /* Mark the buffer as done if the EOF marker is set. */
 492        if (data[1] & UVC_STREAM_EOF && buf->buf.bytesused != 0) {
 493                uvc_trace(UVC_TRACE_FRAME, "Frame complete (EOF found).\n");
 494                if (data[0] == len)
 495                        uvc_trace(UVC_TRACE_FRAME, "EOF in empty payload.\n");
 496                buf->state = UVC_BUF_STATE_READY;
 497                if (stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID)
 498                        stream->last_fid ^= UVC_STREAM_FID;
 499        }
 500}
 501
 502/* Video payload encoding is handled by uvc_video_encode_header() and
 503 * uvc_video_encode_data(). Only bulk transfers are currently supported.
 504 *
 505 * uvc_video_encode_header is called at the start of a payload. It adds header
 506 * data to the transfer buffer and returns the header size. As the only known
 507 * UVC output device transfers a whole frame in a single payload, the EOF bit
 508 * is always set in the header.
 509 *
 510 * uvc_video_encode_data is called for every URB and copies the data from the
 511 * video buffer to the transfer buffer.
 512 */
 513static int uvc_video_encode_header(struct uvc_streaming *stream,
 514                struct uvc_buffer *buf, __u8 *data, int len)
 515{
 516        data[0] = 2;    /* Header length */
 517        data[1] = UVC_STREAM_EOH | UVC_STREAM_EOF
 518                | (stream->last_fid & UVC_STREAM_FID);
 519        return 2;
 520}
 521
 522static int uvc_video_encode_data(struct uvc_streaming *stream,
 523                struct uvc_buffer *buf, __u8 *data, int len)
 524{
 525        struct uvc_video_queue *queue = &stream->queue;
 526        unsigned int nbytes;
 527        void *mem;
 528
 529        /* Copy video data to the URB buffer. */
 530        mem = queue->mem + buf->buf.m.offset + queue->buf_used;
 531        nbytes = min((unsigned int)len, buf->buf.bytesused - queue->buf_used);
 532        nbytes = min(stream->bulk.max_payload_size - stream->bulk.payload_size,
 533                        nbytes);
 534        memcpy(data, mem, nbytes);
 535
 536        queue->buf_used += nbytes;
 537
 538        return nbytes;
 539}
 540
 541/* ------------------------------------------------------------------------
 542 * URB handling
 543 */
 544
 545/*
 546 * Completion handler for video URBs.
 547 */
 548static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
 549        struct uvc_buffer *buf)
 550{
 551        u8 *mem;
 552        int ret, i;
 553
 554        for (i = 0; i < urb->number_of_packets; ++i) {
 555                if (urb->iso_frame_desc[i].status < 0) {
 556                        uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame "
 557                                "lost (%d).\n", urb->iso_frame_desc[i].status);
 558                        continue;
 559                }
 560
 561                /* Decode the payload header. */
 562                mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
 563                do {
 564                        ret = uvc_video_decode_start(stream, buf, mem,
 565                                urb->iso_frame_desc[i].actual_length);
 566                        if (ret == -EAGAIN)
 567                                buf = uvc_queue_next_buffer(&stream->queue,
 568                                                            buf);
 569                } while (ret == -EAGAIN);
 570
 571                if (ret < 0)
 572                        continue;
 573
 574                /* Decode the payload data. */
 575                uvc_video_decode_data(stream, buf, mem + ret,
 576                        urb->iso_frame_desc[i].actual_length - ret);
 577
 578                /* Process the header again. */
 579                uvc_video_decode_end(stream, buf, mem,
 580                        urb->iso_frame_desc[i].actual_length);
 581
 582                if (buf->state == UVC_BUF_STATE_READY)
 583                        buf = uvc_queue_next_buffer(&stream->queue, buf);
 584        }
 585}
 586
 587static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
 588        struct uvc_buffer *buf)
 589{
 590        u8 *mem;
 591        int len, ret;
 592
 593        if (urb->actual_length == 0)
 594                return;
 595
 596        mem = urb->transfer_buffer;
 597        len = urb->actual_length;
 598        stream->bulk.payload_size += len;
 599
 600        /* If the URB is the first of its payload, decode and save the
 601         * header.
 602         */
 603        if (stream->bulk.header_size == 0 && !stream->bulk.skip_payload) {
 604                do {
 605                        ret = uvc_video_decode_start(stream, buf, mem, len);
 606                        if (ret == -EAGAIN)
 607                                buf = uvc_queue_next_buffer(&stream->queue,
 608                                                            buf);
 609                } while (ret == -EAGAIN);
 610
 611                /* If an error occured skip the rest of the payload. */
 612                if (ret < 0 || buf == NULL) {
 613                        stream->bulk.skip_payload = 1;
 614                } else {
 615                        memcpy(stream->bulk.header, mem, ret);
 616                        stream->bulk.header_size = ret;
 617
 618                        mem += ret;
 619                        len -= ret;
 620                }
 621        }
 622
 623        /* The buffer queue might have been cancelled while a bulk transfer
 624         * was in progress, so we can reach here with buf equal to NULL. Make
 625         * sure buf is never dereferenced if NULL.
 626         */
 627
 628        /* Process video data. */
 629        if (!stream->bulk.skip_payload && buf != NULL)
 630                uvc_video_decode_data(stream, buf, mem, len);
 631
 632        /* Detect the payload end by a URB smaller than the maximum size (or
 633         * a payload size equal to the maximum) and process the header again.
 634         */
 635        if (urb->actual_length < urb->transfer_buffer_length ||
 636            stream->bulk.payload_size >= stream->bulk.max_payload_size) {
 637                if (!stream->bulk.skip_payload && buf != NULL) {
 638                        uvc_video_decode_end(stream, buf, stream->bulk.header,
 639                                stream->bulk.payload_size);
 640                        if (buf->state == UVC_BUF_STATE_READY)
 641                                buf = uvc_queue_next_buffer(&stream->queue,
 642                                                            buf);
 643                }
 644
 645                stream->bulk.header_size = 0;
 646                stream->bulk.skip_payload = 0;
 647                stream->bulk.payload_size = 0;
 648        }
 649}
 650
 651static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream,
 652        struct uvc_buffer *buf)
 653{
 654        u8 *mem = urb->transfer_buffer;
 655        int len = stream->urb_size, ret;
 656
 657        if (buf == NULL) {
 658                urb->transfer_buffer_length = 0;
 659                return;
 660        }
 661
 662        /* If the URB is the first of its payload, add the header. */
 663        if (stream->bulk.header_size == 0) {
 664                ret = uvc_video_encode_header(stream, buf, mem, len);
 665                stream->bulk.header_size = ret;
 666                stream->bulk.payload_size += ret;
 667                mem += ret;
 668                len -= ret;
 669        }
 670
 671        /* Process video data. */
 672        ret = uvc_video_encode_data(stream, buf, mem, len);
 673
 674        stream->bulk.payload_size += ret;
 675        len -= ret;
 676
 677        if (buf->buf.bytesused == stream->queue.buf_used ||
 678            stream->bulk.payload_size == stream->bulk.max_payload_size) {
 679                if (buf->buf.bytesused == stream->queue.buf_used) {
 680                        stream->queue.buf_used = 0;
 681                        buf->state = UVC_BUF_STATE_READY;
 682                        uvc_queue_next_buffer(&stream->queue, buf);
 683                        stream->last_fid ^= UVC_STREAM_FID;
 684                }
 685
 686                stream->bulk.header_size = 0;
 687                stream->bulk.payload_size = 0;
 688        }
 689
 690        urb->transfer_buffer_length = stream->urb_size - len;
 691}
 692
 693static void uvc_video_complete(struct urb *urb)
 694{
 695        struct uvc_streaming *stream = urb->context;
 696        struct uvc_video_queue *queue = &stream->queue;
 697        struct uvc_buffer *buf = NULL;
 698        unsigned long flags;
 699        int ret;
 700
 701        switch (urb->status) {
 702        case 0:
 703                break;
 704
 705        default:
 706                uvc_printk(KERN_WARNING, "Non-zero status (%d) in video "
 707                        "completion handler.\n", urb->status);
 708
 709        case -ENOENT:           /* usb_kill_urb() called. */
 710                if (stream->frozen)
 711                        return;
 712
 713        case -ECONNRESET:       /* usb_unlink_urb() called. */
 714        case -ESHUTDOWN:        /* The endpoint is being disabled. */
 715                uvc_queue_cancel(queue, urb->status == -ESHUTDOWN);
 716                return;
 717        }
 718
 719        spin_lock_irqsave(&queue->irqlock, flags);
 720        if (!list_empty(&queue->irqqueue))
 721                buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
 722                                       queue);
 723        spin_unlock_irqrestore(&queue->irqlock, flags);
 724
 725        stream->decode(urb, stream, buf);
 726
 727        if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
 728                uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
 729                        ret);
 730        }
 731}
 732
 733/*
 734 * Free transfer buffers.
 735 */
 736static void uvc_free_urb_buffers(struct uvc_streaming *stream)
 737{
 738        unsigned int i;
 739
 740        for (i = 0; i < UVC_URBS; ++i) {
 741                if (stream->urb_buffer[i]) {
 742                        usb_free_coherent(stream->dev->udev, stream->urb_size,
 743                                stream->urb_buffer[i], stream->urb_dma[i]);
 744                        stream->urb_buffer[i] = NULL;
 745                }
 746        }
 747
 748        stream->urb_size = 0;
 749}
 750
 751/*
 752 * Allocate transfer buffers. This function can be called with buffers
 753 * already allocated when resuming from suspend, in which case it will
 754 * return without touching the buffers.
 755 *
 756 * Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the
 757 * system is too low on memory try successively smaller numbers of packets
 758 * until allocation succeeds.
 759 *
 760 * Return the number of allocated packets on success or 0 when out of memory.
 761 */
 762static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
 763        unsigned int size, unsigned int psize, gfp_t gfp_flags)
 764{
 765        unsigned int npackets;
 766        unsigned int i;
 767
 768        /* Buffers are already allocated, bail out. */
 769        if (stream->urb_size)
 770                return stream->urb_size / psize;
 771
 772        /* Compute the number of packets. Bulk endpoints might transfer UVC
 773         * payloads accross multiple URBs.
 774         */
 775        npackets = DIV_ROUND_UP(size, psize);
 776        if (npackets > UVC_MAX_PACKETS)
 777                npackets = UVC_MAX_PACKETS;
 778
 779        /* Retry allocations until one succeed. */
 780        for (; npackets > 1; npackets /= 2) {
 781                for (i = 0; i < UVC_URBS; ++i) {
 782                        stream->urb_size = psize * npackets;
 783                        stream->urb_buffer[i] = usb_alloc_coherent(
 784                                stream->dev->udev, stream->urb_size,
 785                                gfp_flags | __GFP_NOWARN, &stream->urb_dma[i]);
 786                        if (!stream->urb_buffer[i]) {
 787                                uvc_free_urb_buffers(stream);
 788                                break;
 789                        }
 790                }
 791
 792                if (i == UVC_URBS) {
 793                        uvc_trace(UVC_TRACE_VIDEO, "Allocated %u URB buffers "
 794                                "of %ux%u bytes each.\n", UVC_URBS, npackets,
 795                                psize);
 796                        return npackets;
 797                }
 798        }
 799
 800        uvc_trace(UVC_TRACE_VIDEO, "Failed to allocate URB buffers (%u bytes "
 801                "per packet).\n", psize);
 802        return 0;
 803}
 804
 805/*
 806 * Uninitialize isochronous/bulk URBs and free transfer buffers.
 807 */
 808static void uvc_uninit_video(struct uvc_streaming *stream, int free_buffers)
 809{
 810        struct urb *urb;
 811        unsigned int i;
 812
 813        for (i = 0; i < UVC_URBS; ++i) {
 814                urb = stream->urb[i];
 815                if (urb == NULL)
 816                        continue;
 817
 818                usb_kill_urb(urb);
 819                usb_free_urb(urb);
 820                stream->urb[i] = NULL;
 821        }
 822
 823        if (free_buffers)
 824                uvc_free_urb_buffers(stream);
 825}
 826
 827/*
 828 * Initialize isochronous URBs and allocate transfer buffers. The packet size
 829 * is given by the endpoint.
 830 */
 831static int uvc_init_video_isoc(struct uvc_streaming *stream,
 832        struct usb_host_endpoint *ep, gfp_t gfp_flags)
 833{
 834        struct urb *urb;
 835        unsigned int npackets, i, j;
 836        u16 psize;
 837        u32 size;
 838
 839        psize = le16_to_cpu(ep->desc.wMaxPacketSize);
 840        psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
 841        size = stream->ctrl.dwMaxVideoFrameSize;
 842
 843        npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
 844        if (npackets == 0)
 845                return -ENOMEM;
 846
 847        size = npackets * psize;
 848
 849        for (i = 0; i < UVC_URBS; ++i) {
 850                urb = usb_alloc_urb(npackets, gfp_flags);
 851                if (urb == NULL) {
 852                        uvc_uninit_video(stream, 1);
 853                        return -ENOMEM;
 854                }
 855
 856                urb->dev = stream->dev->udev;
 857                urb->context = stream;
 858                urb->pipe = usb_rcvisocpipe(stream->dev->udev,
 859                                ep->desc.bEndpointAddress);
 860                urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
 861                urb->interval = ep->desc.bInterval;
 862                urb->transfer_buffer = stream->urb_buffer[i];
 863                urb->transfer_dma = stream->urb_dma[i];
 864                urb->complete = uvc_video_complete;
 865                urb->number_of_packets = npackets;
 866                urb->transfer_buffer_length = size;
 867
 868                for (j = 0; j < npackets; ++j) {
 869                        urb->iso_frame_desc[j].offset = j * psize;
 870                        urb->iso_frame_desc[j].length = psize;
 871                }
 872
 873                stream->urb[i] = urb;
 874        }
 875
 876        return 0;
 877}
 878
 879/*
 880 * Initialize bulk URBs and allocate transfer buffers. The packet size is
 881 * given by the endpoint.
 882 */
 883static int uvc_init_video_bulk(struct uvc_streaming *stream,
 884        struct usb_host_endpoint *ep, gfp_t gfp_flags)
 885{
 886        struct urb *urb;
 887        unsigned int npackets, pipe, i;
 888        u16 psize;
 889        u32 size;
 890
 891        psize = le16_to_cpu(ep->desc.wMaxPacketSize) & 0x07ff;
 892        size = stream->ctrl.dwMaxPayloadTransferSize;
 893        stream->bulk.max_payload_size = size;
 894
 895        npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
 896        if (npackets == 0)
 897                return -ENOMEM;
 898
 899        size = npackets * psize;
 900
 901        if (usb_endpoint_dir_in(&ep->desc))
 902                pipe = usb_rcvbulkpipe(stream->dev->udev,
 903                                       ep->desc.bEndpointAddress);
 904        else
 905                pipe = usb_sndbulkpipe(stream->dev->udev,
 906                                       ep->desc.bEndpointAddress);
 907
 908        if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
 909                size = 0;
 910
 911        for (i = 0; i < UVC_URBS; ++i) {
 912                urb = usb_alloc_urb(0, gfp_flags);
 913                if (urb == NULL) {
 914                        uvc_uninit_video(stream, 1);
 915                        return -ENOMEM;
 916                }
 917
 918                usb_fill_bulk_urb(urb, stream->dev->udev, pipe,
 919                        stream->urb_buffer[i], size, uvc_video_complete,
 920                        stream);
 921                urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
 922                urb->transfer_dma = stream->urb_dma[i];
 923
 924                stream->urb[i] = urb;
 925        }
 926
 927        return 0;
 928}
 929
 930/*
 931 * Initialize isochronous/bulk URBs and allocate transfer buffers.
 932 */
 933static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
 934{
 935        struct usb_interface *intf = stream->intf;
 936        struct usb_host_endpoint *ep;
 937        unsigned int i;
 938        int ret;
 939
 940        stream->last_fid = -1;
 941        stream->bulk.header_size = 0;
 942        stream->bulk.skip_payload = 0;
 943        stream->bulk.payload_size = 0;
 944
 945        if (intf->num_altsetting > 1) {
 946                struct usb_host_endpoint *best_ep = NULL;
 947                unsigned int best_psize = 3 * 1024;
 948                unsigned int bandwidth;
 949                unsigned int uninitialized_var(altsetting);
 950                int intfnum = stream->intfnum;
 951
 952                /* Isochronous endpoint, select the alternate setting. */
 953                bandwidth = stream->ctrl.dwMaxPayloadTransferSize;
 954
 955                if (bandwidth == 0) {
 956                        uvc_trace(UVC_TRACE_VIDEO, "Device requested null "
 957                                "bandwidth, defaulting to lowest.\n");
 958                        bandwidth = 1;
 959                } else {
 960                        uvc_trace(UVC_TRACE_VIDEO, "Device requested %u "
 961                                "B/frame bandwidth.\n", bandwidth);
 962                }
 963
 964                for (i = 0; i < intf->num_altsetting; ++i) {
 965                        struct usb_host_interface *alts;
 966                        unsigned int psize;
 967
 968                        alts = &intf->altsetting[i];
 969                        ep = uvc_find_endpoint(alts,
 970                                stream->header.bEndpointAddress);
 971                        if (ep == NULL)
 972                                continue;
 973
 974                        /* Check if the bandwidth is high enough. */
 975                        psize = le16_to_cpu(ep->desc.wMaxPacketSize);
 976                        psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
 977                        if (psize >= bandwidth && psize <= best_psize) {
 978                                altsetting = i;
 979                                best_psize = psize;
 980                                best_ep = ep;
 981                        }
 982                }
 983
 984                if (best_ep == NULL) {
 985                        uvc_trace(UVC_TRACE_VIDEO, "No fast enough alt setting "
 986                                "for requested bandwidth.\n");
 987                        return -EIO;
 988                }
 989
 990                uvc_trace(UVC_TRACE_VIDEO, "Selecting alternate setting %u "
 991                        "(%u B/frame bandwidth).\n", altsetting, best_psize);
 992
 993                ret = usb_set_interface(stream->dev->udev, intfnum, altsetting);
 994                if (ret < 0)
 995                        return ret;
 996
 997                ret = uvc_init_video_isoc(stream, best_ep, gfp_flags);
 998        } else {
 999                /* Bulk endpoint, proceed to URB initialization. */
1000                ep = uvc_find_endpoint(&intf->altsetting[0],
1001                                stream->header.bEndpointAddress);
1002                if (ep == NULL)
1003                        return -EIO;
1004
1005                ret = uvc_init_video_bulk(stream, ep, gfp_flags);
1006        }
1007
1008        if (ret < 0)
1009                return ret;
1010
1011        /* Submit the URBs. */
1012        for (i = 0; i < UVC_URBS; ++i) {
1013                ret = usb_submit_urb(stream->urb[i], gfp_flags);
1014                if (ret < 0) {
1015                        uvc_printk(KERN_ERR, "Failed to submit URB %u "
1016                                        "(%d).\n", i, ret);
1017                        uvc_uninit_video(stream, 1);
1018                        return ret;
1019                }
1020        }
1021
1022        return 0;
1023}
1024
1025/* --------------------------------------------------------------------------
1026 * Suspend/resume
1027 */
1028
1029/*
1030 * Stop streaming without disabling the video queue.
1031 *
1032 * To let userspace applications resume without trouble, we must not touch the
1033 * video buffers in any way. We mark the device as frozen to make sure the URB
1034 * completion handler won't try to cancel the queue when we kill the URBs.
1035 */
1036int uvc_video_suspend(struct uvc_streaming *stream)
1037{
1038        if (!uvc_queue_streaming(&stream->queue))
1039                return 0;
1040
1041        stream->frozen = 1;
1042        uvc_uninit_video(stream, 0);
1043        usb_set_interface(stream->dev->udev, stream->intfnum, 0);
1044        return 0;
1045}
1046
1047/*
1048 * Reconfigure the video interface and restart streaming if it was enabled
1049 * before suspend.
1050 *
1051 * If an error occurs, disable the video queue. This will wake all pending
1052 * buffers, making sure userspace applications are notified of the problem
1053 * instead of waiting forever.
1054 */
1055int uvc_video_resume(struct uvc_streaming *stream)
1056{
1057        int ret;
1058
1059        stream->frozen = 0;
1060
1061        ret = uvc_commit_video(stream, &stream->ctrl);
1062        if (ret < 0) {
1063                uvc_queue_enable(&stream->queue, 0);
1064                return ret;
1065        }
1066
1067        if (!uvc_queue_streaming(&stream->queue))
1068                return 0;
1069
1070        ret = uvc_init_video(stream, GFP_NOIO);
1071        if (ret < 0)
1072                uvc_queue_enable(&stream->queue, 0);
1073
1074        return ret;
1075}
1076
1077/* ------------------------------------------------------------------------
1078 * Video device
1079 */
1080
1081/*
1082 * Initialize the UVC video device by switching to alternate setting 0 and
1083 * retrieve the default format.
1084 *
1085 * Some cameras (namely the Fuji Finepix) set the format and frame
1086 * indexes to zero. The UVC standard doesn't clearly make this a spec
1087 * violation, so try to silently fix the values if possible.
1088 *
1089 * This function is called before registering the device with V4L.
1090 */
1091int uvc_video_init(struct uvc_streaming *stream)
1092{
1093        struct uvc_streaming_control *probe = &stream->ctrl;
1094        struct uvc_format *format = NULL;
1095        struct uvc_frame *frame = NULL;
1096        unsigned int i;
1097        int ret;
1098
1099        if (stream->nformats == 0) {
1100                uvc_printk(KERN_INFO, "No supported video formats found.\n");
1101                return -EINVAL;
1102        }
1103
1104        atomic_set(&stream->active, 0);
1105
1106        /* Initialize the video buffers queue. */
1107        uvc_queue_init(&stream->queue, stream->type);
1108
1109        /* Alternate setting 0 should be the default, yet the XBox Live Vision
1110         * Cam (and possibly other devices) crash or otherwise misbehave if
1111         * they don't receive a SET_INTERFACE request before any other video
1112         * control request.
1113         */
1114        usb_set_interface(stream->dev->udev, stream->intfnum, 0);
1115
1116        /* Set the streaming probe control with default streaming parameters
1117         * retrieved from the device. Webcams that don't suport GET_DEF
1118         * requests on the probe control will just keep their current streaming
1119         * parameters.
1120         */
1121        if (uvc_get_video_ctrl(stream, probe, 1, UVC_GET_DEF) == 0)
1122                uvc_set_video_ctrl(stream, probe, 1);
1123
1124        /* Initialize the streaming parameters with the probe control current
1125         * value. This makes sure SET_CUR requests on the streaming commit
1126         * control will always use values retrieved from a successful GET_CUR
1127         * request on the probe control, as required by the UVC specification.
1128         */
1129        ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);
1130        if (ret < 0)
1131                return ret;
1132
1133        /* Check if the default format descriptor exists. Use the first
1134         * available format otherwise.
1135         */
1136        for (i = stream->nformats; i > 0; --i) {
1137                format = &stream->format[i-1];
1138                if (format->index == probe->bFormatIndex)
1139                        break;
1140        }
1141
1142        if (format->nframes == 0) {
1143                uvc_printk(KERN_INFO, "No frame descriptor found for the "
1144                        "default format.\n");
1145                return -EINVAL;
1146        }
1147
1148        /* Zero bFrameIndex might be correct. Stream-based formats (including
1149         * MPEG-2 TS and DV) do not support frames but have a dummy frame
1150         * descriptor with bFrameIndex set to zero. If the default frame
1151         * descriptor is not found, use the first available frame.
1152         */
1153        for (i = format->nframes; i > 0; --i) {
1154                frame = &format->frame[i-1];
1155                if (frame->bFrameIndex == probe->bFrameIndex)
1156                        break;
1157        }
1158
1159        probe->bFormatIndex = format->index;
1160        probe->bFrameIndex = frame->bFrameIndex;
1161
1162        stream->cur_format = format;
1163        stream->cur_frame = frame;
1164
1165        /* Select the video decoding function */
1166        if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
1167                if (stream->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)
1168                        stream->decode = uvc_video_decode_isight;
1169                else if (stream->intf->num_altsetting > 1)
1170                        stream->decode = uvc_video_decode_isoc;
1171                else
1172                        stream->decode = uvc_video_decode_bulk;
1173        } else {
1174                if (stream->intf->num_altsetting == 1)
1175                        stream->decode = uvc_video_encode_bulk;
1176                else {
1177                        uvc_printk(KERN_INFO, "Isochronous endpoints are not "
1178                                "supported for video output devices.\n");
1179                        return -EINVAL;
1180                }
1181        }
1182
1183        return 0;
1184}
1185
1186/*
1187 * Enable or disable the video stream.
1188 */
1189int uvc_video_enable(struct uvc_streaming *stream, int enable)
1190{
1191        int ret;
1192
1193        if (!enable) {
1194                uvc_uninit_video(stream, 1);
1195                usb_set_interface(stream->dev->udev, stream->intfnum, 0);
1196                uvc_queue_enable(&stream->queue, 0);
1197                return 0;
1198        }
1199
1200        if ((stream->cur_format->flags & UVC_FMT_FLAG_COMPRESSED) ||
1201            uvc_no_drop_param)
1202                stream->queue.flags &= ~UVC_QUEUE_DROP_INCOMPLETE;
1203        else
1204                stream->queue.flags |= UVC_QUEUE_DROP_INCOMPLETE;
1205
1206        ret = uvc_queue_enable(&stream->queue, 1);
1207        if (ret < 0)
1208                return ret;
1209
1210        /* Commit the streaming parameters. */
1211        ret = uvc_commit_video(stream, &stream->ctrl);
1212        if (ret < 0)
1213                return ret;
1214
1215        return uvc_init_video(stream, GFP_KERNEL);
1216}
1217
1218