/* * uvc_video.c -- USB Video Class driver - Video handling * * Copyright (C) 2005-2008 * Laurent Pinchart (laurent.pinchart@skynet.be) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * */ #include #include #include #include #include #include #include #include #include #include #include #include "uvcvideo.h" /* ------------------------------------------------------------------------ * UVC Controls */ static int __uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit, __u8 intfnum, __u8 cs, void *data, __u16 size, int timeout) { __u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE; unsigned int pipe; int ret; pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0) : usb_sndctrlpipe(dev->udev, 0); type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT; ret = usb_control_msg(dev->udev, pipe, query, type, cs << 8, unit << 8 | intfnum, data, size, timeout); if (ret != size) { uvc_printk(KERN_ERR, "Failed to query (%u) UVC control %u " "(unit %u) : %d (exp. %u).\n", query, cs, unit, ret, size); return -EIO; } return 0; } int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit, __u8 intfnum, __u8 cs, void *data, __u16 size) { return __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size, UVC_CTRL_CONTROL_TIMEOUT); } static void uvc_fixup_buffer_size(struct uvc_video_device *video, struct uvc_streaming_control *ctrl) { struct uvc_format *format; struct uvc_frame *frame; if (ctrl->bFormatIndex <= 0 || ctrl->bFormatIndex > video->streaming->nformats) return; format = &video->streaming->format[ctrl->bFormatIndex - 1]; if (ctrl->bFrameIndex <= 0 || ctrl->bFrameIndex > format->nframes) return; frame = &format->frame[ctrl->bFrameIndex - 1]; if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) || (ctrl->dwMaxVideoFrameSize == 0 && video->dev->uvc_version < 0x0110)) ctrl->dwMaxVideoFrameSize = frame->dwMaxVideoFrameBufferSize; } static int uvc_get_video_ctrl(struct uvc_video_device *video, struct uvc_streaming_control *ctrl, int probe, __u8 query) { __u8 data[34]; __u8 size; int ret; size = video->dev->uvc_version >= 0x0110 ? 34 : 26; ret = __uvc_query_ctrl(video->dev, query, 0, video->streaming->intfnum, probe ? VS_PROBE_CONTROL : VS_COMMIT_CONTROL, &data, size, UVC_CTRL_STREAMING_TIMEOUT); if (ret < 0) return ret; ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]); ctrl->bFormatIndex = data[2]; ctrl->bFrameIndex = data[3]; ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]); ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]); ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]); ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]); ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]); ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]); ctrl->dwMaxVideoFrameSize = le32_to_cpu(get_unaligned((__le32 *)&data[18])); ctrl->dwMaxPayloadTransferSize = le32_to_cpu(get_unaligned((__le32 *)&data[22])); if (size == 34) { ctrl->dwClockFrequency = le32_to_cpu(get_unaligned((__le32 *)&data[26])); ctrl->bmFramingInfo = data[30]; ctrl->bPreferedVersion = data[31]; ctrl->bMinVersion = data[32]; ctrl->bMaxVersion = data[33]; } else { ctrl->dwClockFrequency = video->dev->clock_frequency; ctrl->bmFramingInfo = 0; ctrl->bPreferedVersion = 0; ctrl->bMinVersion = 0; ctrl->bMaxVersion = 0; } /* Some broken devices return a null or wrong dwMaxVideoFrameSize. * Try to get the value from the format and frame descriptor. */ uvc_fixup_buffer_size(video, ctrl); return 0; } int uvc_set_video_ctrl(struct uvc_video_device *video, struct uvc_streaming_control *ctrl, int probe) { __u8 data[34]; __u8 size; size = video->dev->uvc_version >= 0x0110 ? 34 : 26; memset(data, 0, sizeof data); *(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint); data[2] = ctrl->bFormatIndex; data[3] = ctrl->bFrameIndex; *(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval); *(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate); *(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate); *(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality); *(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize); *(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay); /* Note: Some of the fields below are not required for IN devices (see * UVC spec, 4.3.1.1), but we still copy them in case support for OUT * devices is added in the future. */ put_unaligned(cpu_to_le32(ctrl->dwMaxVideoFrameSize), (__le32 *)&data[18]); put_unaligned(cpu_to_le32(ctrl->dwMaxPayloadTransferSize), (__le32 *)&data[22]); if (size == 34) { put_unaligned(cpu_to_le32(ctrl->dwClockFrequency), (__le32 *)&data[26]); data[30] = ctrl->bmFramingInfo; data[31] = ctrl->bPreferedVersion; data[32] = ctrl->bMinVersion; data[33] = ctrl->bMaxVersion; } return __uvc_query_ctrl(video->dev, SET_CUR, 0, video->streaming->intfnum, probe ? VS_PROBE_CONTROL : VS_COMMIT_CONTROL, &data, size, UVC_CTRL_STREAMING_TIMEOUT); } int uvc_probe_video(struct uvc_video_device *video, struct uvc_streaming_control *probe) { struct uvc_streaming_control probe_min, probe_max; __u16 bandwidth; unsigned int i; int ret; mutex_lock(&video->streaming->mutex); /* Perform probing. The device should adjust the requested values * according to its capabilities. However, some devices, namely the * first generation UVC Logitech webcams, don't implement the Video * Probe control properly, and just return the needed bandwidth. For * that reason, if the needed bandwidth exceeds the maximum available * bandwidth, try to lower the quality. */ if ((ret = uvc_set_video_ctrl(video, probe, 1)) < 0) goto done; /* Get the minimum and maximum values for compression settings. */ if (!(video->dev->quirks & UVC_QUIRK_PROBE_MINMAX)) { ret = uvc_get_video_ctrl(video, &probe_min, 1, GET_MIN); if (ret < 0) goto done; ret = uvc_get_video_ctrl(video, &probe_max, 1, GET_MAX); if (ret < 0) goto done; probe->wCompQuality = probe_max.wCompQuality; } for (i = 0; i < 2; ++i) { if ((ret = uvc_set_video_ctrl(video, probe, 1)) < 0 || (ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR)) < 0) goto done; if (video->streaming->intf->num_altsetting == 1) break; bandwidth = probe->dwMaxPayloadTransferSize; if (bandwidth <= video->streaming->maxpsize) break; if (video->dev->quirks & UVC_QUIRK_PROBE_MINMAX) { ret = -ENOSPC; goto done; } /* TODO: negotiate compression parameters */ probe->wKeyFrameRate = probe_min.wKeyFrameRate; probe->wPFrameRate = probe_min.wPFrameRate; probe->wCompQuality = probe_max.wCompQuality; probe->wCompWindowSize = probe_min.wCompWindowSize; } done: mutex_unlock(&video->streaming->mutex); return ret; } /* ------------------------------------------------------------------------ * Video codecs */ /* Values for bmHeaderInfo (Video and Still Image Payload Headers, 2.4.3.3) */ #define UVC_STREAM_EOH (1 << 7) #define UVC_STREAM_ERR (1 << 6) #define UVC_STREAM_STI (1 << 5) #define UVC_STREAM_RES (1 << 4) #define UVC_STREAM_SCR (1 << 3) #define UVC_STREAM_PTS (1 << 2) #define UVC_STREAM_EOF (1 << 1) #define UVC_STREAM_FID (1 << 0) /* Video payload decoding is handled by uvc_video_decode_start(), * uvc_video_decode_data() and uvc_video_decode_end(). * * uvc_video_decode_start is called with URB data at the start of a bulk or * isochronous payload. It processes header data and returns the header size * in bytes if successful. If an error occurs, it returns a negative error * code. The following error codes have special meanings. * * - EAGAIN informs the caller that the current video buffer should be marked * as done, and that the function should be called again with the same data * and a new video buffer. This is used when end of frame conditions can be * reliably detected at the beginning of the next frame only. * * If an error other than -EAGAIN is returned, the caller will drop the current * payload. No call to uvc_video_decode_data and uvc_video_decode_end will be * made until the next payload. -ENODATA can be used to drop the current * payload if no other error code is appropriate. * * uvc_video_decode_data is called for every URB with URB data. It copies the * data to the video buffer. * * uvc_video_decode_end is called with header data at the end of a bulk or * isochronous payload. It performs any additional header data processing and * returns 0 or a negative error code if an error occured. As header data have * already been processed by uvc_video_decode_start, this functions isn't * required to perform sanity checks a second time. * * For isochronous transfers where a payload is always transfered in a single * URB, the three functions will be called in a row. * * To let the decoder process header data and update its internal state even * when no video buffer is available, uvc_video_decode_start must be prepared * to be called with a NULL buf parameter. uvc_video_decode_data and * uvc_video_decode_end will never be called with a NULL buffer. */ static int uvc_video_decode_start(struct uvc_video_device *video, struct uvc_buffer *buf, const __u8 *data, int len) { __u8 fid; /* Sanity checks: * - packet must be at least 2 bytes long * - bHeaderLength value must be at least 2 bytes (see above) * - bHeaderLength value can't be larger than the packet size. */ if (len < 2 || data[0] < 2 || data[0] > len) return -EINVAL; /* Skip payloads marked with the error bit ("error frames"). */ if (data[1] & UVC_STREAM_ERR) { uvc_trace(UVC_TRACE_FRAME, "Dropping payload (error bit " "set).\n"); return -ENODATA; } fid = data[1] & UVC_STREAM_FID; /* Store the payload FID bit and return immediately when the buffer is * NULL. */ if (buf == NULL) { video->last_fid = fid; return -ENODATA; } /* Synchronize to the input stream by waiting for the FID bit to be * toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE. * queue->last_fid is initialized to -1, so the first isochronous * frame will always be in sync. * * If the device doesn't toggle the FID bit, invert video->last_fid * when the EOF bit is set to force synchronisation on the next packet. */ if (buf->state != UVC_BUF_STATE_ACTIVE) { if (fid == video->last_fid) { uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of " "sync).\n"); if ((video->dev->quirks & UVC_QUIRK_STREAM_NO_FID) && (data[1] & UVC_STREAM_EOF)) video->last_fid ^= UVC_STREAM_FID; return -ENODATA; } /* TODO: Handle PTS and SCR. */ buf->state = UVC_BUF_STATE_ACTIVE; } /* Mark the buffer as done if we're at the beginning of a new frame. * End of frame detection is better implemented by checking the EOF * bit (FID bit toggling is delayed by one frame compared to the EOF * bit), but some devices don't set the bit at end of frame (and the * last payload can be lost anyway). We thus must check if the FID has * been toggled. * * queue->last_fid is initialized to -1, so the first isochronous * frame will never trigger an end of frame detection. * * Empty buffers (bytesused == 0) don't trigger end of frame detection * as it doesn't make sense to return an empty buffer. This also * avoids detecting and of frame conditions at FID toggling if the * previous payload had the EOF bit set. */ if (fid != video->last_fid && buf->buf.bytesused != 0) { uvc_trace(UVC_TRACE_FRAME, "Frame complete (FID bit " "toggled).\n"); buf->state = UVC_BUF_STATE_DONE; return -EAGAIN; } video->last_fid = fid; return data[0]; } static void uvc_video_decode_data(struct uvc_video_device *video, struct uvc_buffer *buf, const __u8 *data, int len) { struct uvc_video_queue *queue = &video->queue; unsigned int maxlen, nbytes; void *mem; if (len <= 0) return; /* Copy the video data to the buffer. */ maxlen = buf->buf.length - buf->buf.bytesused; mem = queue->mem + buf->buf.m.offset + buf->buf.bytesused; nbytes = min((unsigned int)len, maxlen); memcpy(mem, data, nbytes); buf->buf.bytesused += nbytes; /* Complete the current frame if the buffer size was exceeded. */ if (len > maxlen) { uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n"); buf->state = UVC_BUF_STATE_DONE; } } static void uvc_video_decode_end(struct uvc_video_device *video, struct uvc_buffer *buf, const __u8 *data, int len) { /* Mark the buffer as done if the EOF marker is set. */ if (data[1] & UVC_STREAM_EOF && buf->buf.bytesused != 0) { uvc_trace(UVC_TRACE_FRAME, "Frame complete (EOF found).\n"); if (data[0] == len) uvc_trace(UVC_TRACE_FRAME, "EOF in empty payload.\n"); buf->state = UVC_BUF_STATE_DONE; if (video->dev->quirks & UVC_QUIRK_STREAM_NO_FID) video->last_fid ^= UVC_STREAM_FID; } } /* ------------------------------------------------------------------------ * URB handling */ /* * Completion handler for video URBs. */ static void uvc_video_decode_isoc(struct urb *urb, struct uvc_video_device *video, struct uvc_buffer *buf) { u8 *mem; int ret, i; for (i = 0; i < urb->number_of_packets; ++i) { if (urb->iso_frame_desc[i].status < 0) { uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame " "lost (%d).\n", urb->iso_frame_desc[i].status); continue; } /* Decode the payload header. */ mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset; do { ret = uvc_video_decode_start(video, buf, mem, urb->iso_frame_desc[i].actual_length); if (ret == -EAGAIN) buf = uvc_queue_next_buffer(&video->queue, buf); } while (ret == -EAGAIN); if (ret < 0) continue; /* Decode the payload data. */ uvc_video_decode_data(video, buf, mem + ret, urb->iso_frame_desc[i].actual_length - ret); /* Process the header again. */ uvc_video_decode_end(video, buf, mem, ret); if (buf->state == UVC_BUF_STATE_DONE || buf->state == UVC_BUF_STATE_ERROR) buf = uvc_queue_next_buffer(&video->queue, buf); } } static void uvc_video_decode_bulk(struct urb *urb, struct uvc_video_device *video, struct uvc_buffer *buf) { u8 *mem; int len, ret; mem = urb->transfer_buffer; len = urb->actual_length; video->bulk.payload_size += len; /* If the URB is the first of its payload, decode and save the * header. */ if (video->bulk.header_size == 0) { do { ret = uvc_video_decode_start(video, buf, mem, len); if (ret == -EAGAIN) buf = uvc_queue_next_buffer(&video->queue, buf); } while (ret == -EAGAIN); /* If an error occured skip the rest of the payload. */ if (ret < 0 || buf == NULL) { video->bulk.skip_payload = 1; return; } video->bulk.header_size = ret; memcpy(video->bulk.header, mem, video->bulk.header_size); mem += ret; len -= ret; } /* The buffer queue might have been cancelled while a bulk transfer * was in progress, so we can reach here with buf equal to NULL. Make * sure buf is never dereferenced if NULL. */ /* Process video data. */ if (!video->bulk.skip_payload && buf != NULL) uvc_video_decode_data(video, buf, mem, len); /* Detect the payload end by a URB smaller than the maximum size (or * a payload size equal to the maximum) and process the header again. */ if (urb->actual_length < urb->transfer_buffer_length || video->bulk.payload_size >= video->bulk.max_payload_size) { if (!video->bulk.skip_payload && buf != NULL) { uvc_video_decode_end(video, buf, video->bulk.header, video->bulk.header_size); if (buf->state == UVC_BUF_STATE_DONE || buf->state == UVC_BUF_STATE_ERROR) buf = uvc_queue_next_buffer(&video->queue, buf); } video->bulk.header_size = 0; video->bulk.skip_payload = 0; video->bulk.payload_size = 0; } } static void uvc_video_complete(struct urb *urb) { struct uvc_video_device *video = urb->context; struct uvc_video_queue *queue = &video->queue; struct uvc_buffer *buf = NULL; unsigned long flags; int ret; switch (urb->status) { case 0: break; default: uvc_printk(KERN_WARNING, "Non-zero status (%d) in video " "completion handler.\n", urb->status); case -ENOENT: /* usb_kill_urb() called. */ if (video->frozen) return; case -ECONNRESET: /* usb_unlink_urb() called. */ case -ESHUTDOWN: /* The endpoint is being disabled. */ uvc_queue_cancel(queue, urb->status == -ESHUTDOWN); return; } spin_lock_irqsave(&queue->irqlock, flags); if (!list_empty(&queue->irqqueue)) buf = list_first_entry(&queue->irqqueue, struct uvc_buffer, queue); spin_unlock_irqrestore(&queue->irqlock, flags); video->decode(urb, video, buf); if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) { uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n", ret); } } /* * Uninitialize isochronous/bulk URBs and free transfer buffers. */ static void uvc_uninit_video(struct uvc_video_device *video) { struct urb *urb; unsigned int i; for (i = 0; i < UVC_URBS; ++i) { if ((urb = video->urb[i]) == NULL) continue; usb_kill_urb(urb); /* urb->transfer_buffer_length is not touched by USB core, so * we can use it here as the buffer length. */ if (video->urb_buffer[i]) { usb_buffer_free(video->dev->udev, urb->transfer_buffer_length, video->urb_buffer[i], urb->transfer_dma); video->urb_buffer[i] = NULL; } usb_free_urb(urb); video->urb[i] = NULL; } } /* * Initialize isochronous URBs and allocate transfer buffers. The packet size * is given by the endpoint. */ static int uvc_init_video_isoc(struct uvc_video_device *video, struct usb_host_endpoint *ep, gfp_t gfp_flags) { struct urb *urb; unsigned int npackets, i, j; __u16 psize; __u32 size; /* Compute the number of isochronous packets to allocate by dividing * the maximum video frame size by the packet size. Limit the result * to UVC_MAX_ISO_PACKETS. */ psize = le16_to_cpu(ep->desc.wMaxPacketSize); psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3)); size = video->streaming->ctrl.dwMaxVideoFrameSize; if (size > UVC_MAX_FRAME_SIZE) return -EINVAL; npackets = (size + psize - 1) / psize; if (npackets > UVC_MAX_ISO_PACKETS) npackets = UVC_MAX_ISO_PACKETS; size = npackets * psize; for (i = 0; i < UVC_URBS; ++i) { urb = usb_alloc_urb(npackets, gfp_flags); if (urb == NULL) { uvc_uninit_video(video); return -ENOMEM; } video->urb_buffer[i] = usb_buffer_alloc(video->dev->udev, size, gfp_flags, &urb->transfer_dma); if (video->urb_buffer[i] == NULL) { usb_free_urb(urb); uvc_uninit_video(video); return -ENOMEM; } urb->dev = video->dev->udev; urb->context = video; urb->pipe = usb_rcvisocpipe(video->dev->udev, ep->desc.bEndpointAddress); urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP; urb->interval = ep->desc.bInterval; urb->transfer_buffer = video->urb_buffer[i]; urb->complete = uvc_video_complete; urb->number_of_packets = npackets; urb->transfer_buffer_length = size; for (j = 0; j < npackets; ++j) { urb->iso_frame_desc[j].offset = j * psize; urb->iso_frame_desc[j].length = psize; } video->urb[i] = urb; } return 0; } /* * Initialize bulk URBs and allocate transfer buffers. The packet size is * given by the endpoint. */ static int uvc_init_video_bulk(struct uvc_video_device *video, struct usb_host_endpoint *ep, gfp_t gfp_flags) { struct urb *urb; unsigned int pipe, i; __u16 psize; __u32 size; /* Compute the bulk URB size. Some devices set the maximum payload * size to a value too high for memory-constrained devices. We must * then transfer the payload accross multiple URBs. To be consistant * with isochronous mode, allocate maximum UVC_MAX_ISO_PACKETS per bulk * URB. */ psize = le16_to_cpu(ep->desc.wMaxPacketSize) & 0x07ff; size = video->streaming->ctrl.dwMaxPayloadTransferSize; video->bulk.max_payload_size = size; if (size > psize * UVC_MAX_ISO_PACKETS) size = psize * UVC_MAX_ISO_PACKETS; pipe = usb_rcvbulkpipe(video->dev->udev, ep->desc.bEndpointAddress); for (i = 0; i < UVC_URBS; ++i) { urb = usb_alloc_urb(0, gfp_flags); if (urb == NULL) { uvc_uninit_video(video); return -ENOMEM; } video->urb_buffer[i] = usb_buffer_alloc(video->dev->udev, size, gfp_flags, &urb->transfer_dma); if (video->urb_buffer[i] == NULL) { usb_free_urb(urb); uvc_uninit_video(video); return -ENOMEM; } usb_fill_bulk_urb(urb, video->dev->udev, pipe, video->urb_buffer[i], size, uvc_video_complete, video); urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; video->urb[i] = urb; } return 0; } /* * Initialize isochronous/bulk URBs and allocate transfer buffers. */ static int uvc_init_video(struct uvc_video_device *video, gfp_t gfp_flags) { struct usb_interface *intf = video->streaming->intf; struct usb_host_interface *alts; struct usb_host_endpoint *ep = NULL; int intfnum = video->streaming->intfnum; unsigned int bandwidth, psize, i; int ret; video->last_fid = -1; video->bulk.header_size = 0; video->bulk.skip_payload = 0; video->bulk.payload_size = 0; if (intf->num_altsetting > 1) { /* Isochronous endpoint, select the alternate setting. */ bandwidth = video->streaming->ctrl.dwMaxPayloadTransferSize; if (bandwidth == 0) { uvc_printk(KERN_WARNING, "device %s requested null " "bandwidth, defaulting to lowest.\n", video->vdev->name); bandwidth = 1; } for (i = 0; i < intf->num_altsetting; ++i) { alts = &intf->altsetting[i]; ep = uvc_find_endpoint(alts, video->streaming->header.bEndpointAddress); if (ep == NULL) continue; /* Check if the bandwidth is high enough. */ psize = le16_to_cpu(ep->desc.wMaxPacketSize); psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3)); if (psize >= bandwidth) break; } if (i >= intf->num_altsetting) return -EIO; if ((ret = usb_set_interface(video->dev->udev, intfnum, i)) < 0) return ret; ret = uvc_init_video_isoc(video, ep, gfp_flags); } else { /* Bulk endpoint, proceed to URB initialization. */ ep = uvc_find_endpoint(&intf->altsetting[0], video->streaming->header.bEndpointAddress); if (ep == NULL) return -EIO; ret = uvc_init_video_bulk(video, ep, gfp_flags); } if (ret < 0) return ret; /* Submit the URBs. */ for (i = 0; i < UVC_URBS; ++i) { if ((ret = usb_submit_urb(video->urb[i], gfp_flags)) < 0) { uvc_printk(KERN_ERR, "Failed to submit URB %u " "(%d).\n", i, ret); uvc_uninit_video(video); return ret; } } return 0; } /* -------------------------------------------------------------------------- * Suspend/resume */ /* * Stop streaming without disabling the video queue. * * To let userspace applications resume without trouble, we must not touch the * video buffers in any way. We mark the device as frozen to make sure the URB * completion handler won't try to cancel the queue when we kill the URBs. */ int uvc_video_suspend(struct uvc_video_device *video) { if (!uvc_queue_streaming(&video->queue)) return 0; video->frozen = 1; uvc_uninit_video(video); usb_set_interface(video->dev->udev, video->streaming->intfnum, 0); return 0; } /* * Reconfigure the video interface and restart streaming if it was enable * before suspend. * * If an error occurs, disable the video queue. This will wake all pending * buffers, making sure userspace applications are notified of the problem * instead of waiting forever. */ int uvc_video_resume(struct uvc_video_device *video) { int ret; video->frozen = 0; if ((ret = uvc_set_video_ctrl(video, &video->streaming->ctrl, 0)) < 0) { uvc_queue_enable(&video->queue, 0); return ret; } if (!uvc_queue_streaming(&video->queue)) return 0; if ((ret = uvc_init_video(video, GFP_NOIO)) < 0) uvc_queue_enable(&video->queue, 0); return ret; } /* ------------------------------------------------------------------------ * Video device */ /* * Initialize the UVC video device by retrieving the default format and * committing it. * * Some cameras (namely the Fuji Finepix) set the format and frame * indexes to zero. The UVC standard doesn't clearly make this a spec * violation, so try to silently fix the values if possible. * * This function is called before registering the device with V4L. */ int uvc_video_init(struct uvc_video_device *video) { struct uvc_streaming_control *probe = &video->streaming->ctrl; struct uvc_format *format = NULL; struct uvc_frame *frame = NULL; unsigned int i; int ret; if (video->streaming->nformats == 0) { uvc_printk(KERN_INFO, "No supported video formats found.\n"); return -EINVAL; } /* Alternate setting 0 should be the default, yet the XBox Live Vision * Cam (and possibly other devices) crash or otherwise misbehave if * they don't receive a SET_INTERFACE request before any other video * control request. */ usb_set_interface(video->dev->udev, video->streaming->intfnum, 0); /* Some webcams don't suport GET_DEF request on the probe control. We * fall back to GET_CUR if GET_DEF fails. */ if ((ret = uvc_get_video_ctrl(video, probe, 1, GET_DEF)) < 0 && (ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR)) < 0) return ret; /* Check if the default format descriptor exists. Use the first * available format otherwise. */ for (i = video->streaming->nformats; i > 0; --i) { format = &video->streaming->format[i-1]; if (format->index == probe->bFormatIndex) break; } if (format->nframes == 0) { uvc_printk(KERN_INFO, "No frame descriptor found for the " "default format.\n"); return -EINVAL; } /* Zero bFrameIndex might be correct. Stream-based formats (including * MPEG-2 TS and DV) do not support frames but have a dummy frame * descriptor with bFrameIndex set to zero. If the default frame * descriptor is not found, use the first avalable frame. */ for (i = format->nframes; i > 0; --i) { frame = &format->frame[i-1]; if (frame->bFrameIndex == probe->bFrameIndex) break; } /* Commit the default settings. */ probe->bFormatIndex = format->index; probe->bFrameIndex = frame->bFrameIndex; if ((ret = uvc_set_video_ctrl(video, probe, 0)) < 0) return ret; video->streaming->cur_format = format; video->streaming->cur_frame = frame; atomic_set(&video->active, 0); /* Select the video decoding function */ if (video->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT) video->decode = uvc_video_decode_isight; else if (video->streaming->intf->num_altsetting > 1) video->decode = uvc_video_decode_isoc; else video->decode = uvc_video_decode_bulk; return 0; } /* * Enable or disable the video stream. */ int uvc_video_enable(struct uvc_video_device *video, int enable) { int ret; if (!enable) { uvc_uninit_video(video); usb_set_interface(video->dev->udev, video->streaming->intfnum, 0); uvc_queue_enable(&video->queue, 0); return 0; } if ((ret = uvc_queue_enable(&video->queue, 1)) < 0) return ret; return uvc_init_video(video, GFP_KERNEL); }