| /* |
| * videobuf2-v4l2.c - V4L2 driver helper framework |
| * |
| * Copyright (C) 2010 Samsung Electronics |
| * |
| * Author: Pawel Osciak <pawel@osciak.com> |
| * Marek Szyprowski <m.szyprowski@samsung.com> |
| * |
| * The vb2_thread implementation was based on code from videobuf-dvb.c: |
| * (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs] |
| * |
| * 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. |
| */ |
| |
| #include <linux/err.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/mm.h> |
| #include <linux/poll.h> |
| #include <linux/slab.h> |
| #include <linux/sched.h> |
| #include <linux/freezer.h> |
| #include <linux/kthread.h> |
| |
| #include <media/v4l2-dev.h> |
| #include <media/v4l2-fh.h> |
| #include <media/v4l2-event.h> |
| #include <media/v4l2-common.h> |
| |
| #include <media/videobuf2-v4l2.h> |
| |
| static int debug; |
| module_param(debug, int, 0644); |
| |
| #define dprintk(level, fmt, arg...) \ |
| do { \ |
| if (debug >= level) \ |
| pr_info("vb2-v4l2: %s: " fmt, __func__, ## arg); \ |
| } while (0) |
| |
| /* Flags that are set by the vb2 core */ |
| #define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \ |
| V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \ |
| V4L2_BUF_FLAG_PREPARED | \ |
| V4L2_BUF_FLAG_TIMESTAMP_MASK) |
| /* Output buffer flags that should be passed on to the driver */ |
| #define V4L2_BUFFER_OUT_FLAGS (V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \ |
| V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_TIMECODE) |
| |
| /** |
| * __verify_planes_array() - verify that the planes array passed in struct |
| * v4l2_buffer from userspace can be safely used |
| */ |
| static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b) |
| { |
| if (!V4L2_TYPE_IS_MULTIPLANAR(b->type)) |
| return 0; |
| |
| /* Is memory for copying plane information present? */ |
| if (b->m.planes == NULL) { |
| dprintk(1, "multi-planar buffer passed but " |
| "planes array not provided\n"); |
| return -EINVAL; |
| } |
| |
| if (b->length < vb->num_planes || b->length > VB2_MAX_PLANES) { |
| dprintk(1, "incorrect planes array length, " |
| "expected %d, got %d\n", vb->num_planes, b->length); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * __verify_length() - Verify that the bytesused value for each plane fits in |
| * the plane length and that the data offset doesn't exceed the bytesused value. |
| */ |
| static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b) |
| { |
| unsigned int length; |
| unsigned int bytesused; |
| unsigned int plane; |
| |
| if (!V4L2_TYPE_IS_OUTPUT(b->type)) |
| return 0; |
| |
| if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) { |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| length = (b->memory == VB2_MEMORY_USERPTR || |
| b->memory == VB2_MEMORY_DMABUF) |
| ? b->m.planes[plane].length |
| : vb->planes[plane].length; |
| bytesused = b->m.planes[plane].bytesused |
| ? b->m.planes[plane].bytesused : length; |
| |
| if (b->m.planes[plane].bytesused > length) |
| return -EINVAL; |
| |
| if (b->m.planes[plane].data_offset > 0 && |
| b->m.planes[plane].data_offset >= bytesused) |
| return -EINVAL; |
| } |
| } else { |
| length = (b->memory == VB2_MEMORY_USERPTR) |
| ? b->length : vb->planes[0].length; |
| |
| if (b->bytesused > length) |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static void __copy_timestamp(struct vb2_buffer *vb, const void *pb) |
| { |
| const struct v4l2_buffer *b = pb; |
| struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); |
| struct vb2_queue *q = vb->vb2_queue; |
| |
| if (q->is_output) { |
| /* |
| * For output buffers copy the timestamp if needed, |
| * and the timecode field and flag if needed. |
| */ |
| if (q->copy_timestamp) |
| vb->timestamp = timeval_to_ns(&b->timestamp); |
| vbuf->flags |= b->flags & V4L2_BUF_FLAG_TIMECODE; |
| if (b->flags & V4L2_BUF_FLAG_TIMECODE) |
| vbuf->timecode = b->timecode; |
| } |
| }; |
| |
| static void vb2_warn_zero_bytesused(struct vb2_buffer *vb) |
| { |
| static bool check_once; |
| |
| if (check_once) |
| return; |
| |
| check_once = true; |
| WARN_ON(1); |
| |
| pr_warn("use of bytesused == 0 is deprecated and will be removed in the future,\n"); |
| if (vb->vb2_queue->allow_zero_bytesused) |
| pr_warn("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n"); |
| else |
| pr_warn("use the actual size instead.\n"); |
| } |
| |
| static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b, |
| const char *opname) |
| { |
| if (b->type != q->type) { |
| dprintk(1, "%s: invalid buffer type\n", opname); |
| return -EINVAL; |
| } |
| |
| if (b->index >= q->num_buffers) { |
| dprintk(1, "%s: buffer index out of range\n", opname); |
| return -EINVAL; |
| } |
| |
| if (q->bufs[b->index] == NULL) { |
| /* Should never happen */ |
| dprintk(1, "%s: buffer is NULL\n", opname); |
| return -EINVAL; |
| } |
| |
| if (b->memory != q->memory) { |
| dprintk(1, "%s: invalid memory type\n", opname); |
| return -EINVAL; |
| } |
| |
| return __verify_planes_array(q->bufs[b->index], b); |
| } |
| |
| /** |
| * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be |
| * returned to userspace |
| */ |
| static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb) |
| { |
| struct v4l2_buffer *b = pb; |
| struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); |
| struct vb2_queue *q = vb->vb2_queue; |
| unsigned int plane; |
| |
| /* Copy back data such as timestamp, flags, etc. */ |
| b->index = vb->index; |
| b->type = vb->type; |
| b->memory = vb->memory; |
| b->bytesused = 0; |
| |
| b->flags = vbuf->flags; |
| b->field = vbuf->field; |
| b->timestamp = ns_to_timeval(vb->timestamp); |
| b->timecode = vbuf->timecode; |
| b->sequence = vbuf->sequence; |
| b->reserved2 = 0; |
| b->reserved = 0; |
| |
| if (q->is_multiplanar) { |
| /* |
| * Fill in plane-related data if userspace provided an array |
| * for it. The caller has already verified memory and size. |
| */ |
| b->length = vb->num_planes; |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| struct v4l2_plane *pdst = &b->m.planes[plane]; |
| struct vb2_plane *psrc = &vb->planes[plane]; |
| |
| pdst->bytesused = psrc->bytesused; |
| pdst->length = psrc->length; |
| if (q->memory == VB2_MEMORY_MMAP) |
| pdst->m.mem_offset = psrc->m.offset; |
| else if (q->memory == VB2_MEMORY_USERPTR) |
| pdst->m.userptr = psrc->m.userptr; |
| else if (q->memory == VB2_MEMORY_DMABUF) |
| pdst->m.fd = psrc->m.fd; |
| pdst->data_offset = psrc->data_offset; |
| memset(pdst->reserved, 0, sizeof(pdst->reserved)); |
| } |
| } else { |
| /* |
| * We use length and offset in v4l2_planes array even for |
| * single-planar buffers, but userspace does not. |
| */ |
| b->length = vb->planes[0].length; |
| b->bytesused = vb->planes[0].bytesused; |
| if (q->memory == VB2_MEMORY_MMAP) |
| b->m.offset = vb->planes[0].m.offset; |
| else if (q->memory == VB2_MEMORY_USERPTR) |
| b->m.userptr = vb->planes[0].m.userptr; |
| else if (q->memory == VB2_MEMORY_DMABUF) |
| b->m.fd = vb->planes[0].m.fd; |
| } |
| |
| /* |
| * Clear any buffer state related flags. |
| */ |
| b->flags &= ~V4L2_BUFFER_MASK_FLAGS; |
| b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK; |
| if (!q->copy_timestamp) { |
| /* |
| * For non-COPY timestamps, drop timestamp source bits |
| * and obtain the timestamp source from the queue. |
| */ |
| b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK; |
| b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK; |
| } |
| |
| switch (vb->state) { |
| case VB2_BUF_STATE_QUEUED: |
| case VB2_BUF_STATE_ACTIVE: |
| b->flags |= V4L2_BUF_FLAG_QUEUED; |
| break; |
| case VB2_BUF_STATE_ERROR: |
| b->flags |= V4L2_BUF_FLAG_ERROR; |
| /* fall through */ |
| case VB2_BUF_STATE_DONE: |
| b->flags |= V4L2_BUF_FLAG_DONE; |
| break; |
| case VB2_BUF_STATE_PREPARED: |
| b->flags |= V4L2_BUF_FLAG_PREPARED; |
| break; |
| case VB2_BUF_STATE_PREPARING: |
| case VB2_BUF_STATE_DEQUEUED: |
| case VB2_BUF_STATE_REQUEUEING: |
| /* nothing */ |
| break; |
| } |
| |
| if (vb2_buffer_in_use(q, vb)) |
| b->flags |= V4L2_BUF_FLAG_MAPPED; |
| |
| if (!q->is_output && |
| b->flags & V4L2_BUF_FLAG_DONE && |
| b->flags & V4L2_BUF_FLAG_LAST) |
| q->last_buffer_dequeued = true; |
| } |
| |
| /** |
| * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a |
| * v4l2_buffer by the userspace. It also verifies that struct |
| * v4l2_buffer has a valid number of planes. |
| */ |
| static int __fill_vb2_buffer(struct vb2_buffer *vb, |
| const void *pb, struct vb2_plane *planes) |
| { |
| struct vb2_queue *q = vb->vb2_queue; |
| const struct v4l2_buffer *b = pb; |
| struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); |
| unsigned int plane; |
| int ret; |
| |
| ret = __verify_length(vb, b); |
| if (ret < 0) { |
| dprintk(1, "plane parameters verification failed: %d\n", ret); |
| return ret; |
| } |
| if (b->field == V4L2_FIELD_ALTERNATE && q->is_output) { |
| /* |
| * If the format's field is ALTERNATE, then the buffer's field |
| * should be either TOP or BOTTOM, not ALTERNATE since that |
| * makes no sense. The driver has to know whether the |
| * buffer represents a top or a bottom field in order to |
| * program any DMA correctly. Using ALTERNATE is wrong, since |
| * that just says that it is either a top or a bottom field, |
| * but not which of the two it is. |
| */ |
| dprintk(1, "the field is incorrectly set to ALTERNATE " |
| "for an output buffer\n"); |
| return -EINVAL; |
| } |
| vb->timestamp = 0; |
| vbuf->sequence = 0; |
| |
| if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) { |
| if (b->memory == VB2_MEMORY_USERPTR) { |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| planes[plane].m.userptr = |
| b->m.planes[plane].m.userptr; |
| planes[plane].length = |
| b->m.planes[plane].length; |
| } |
| } |
| if (b->memory == VB2_MEMORY_DMABUF) { |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| planes[plane].m.fd = |
| b->m.planes[plane].m.fd; |
| planes[plane].length = |
| b->m.planes[plane].length; |
| } |
| } |
| |
| /* Fill in driver-provided information for OUTPUT types */ |
| if (V4L2_TYPE_IS_OUTPUT(b->type)) { |
| /* |
| * Will have to go up to b->length when API starts |
| * accepting variable number of planes. |
| * |
| * If bytesused == 0 for the output buffer, then fall |
| * back to the full buffer size. In that case |
| * userspace clearly never bothered to set it and |
| * it's a safe assumption that they really meant to |
| * use the full plane sizes. |
| * |
| * Some drivers, e.g. old codec drivers, use bytesused == 0 |
| * as a way to indicate that streaming is finished. |
| * In that case, the driver should use the |
| * allow_zero_bytesused flag to keep old userspace |
| * applications working. |
| */ |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| struct vb2_plane *pdst = &planes[plane]; |
| struct v4l2_plane *psrc = &b->m.planes[plane]; |
| |
| if (psrc->bytesused == 0) |
| vb2_warn_zero_bytesused(vb); |
| |
| if (vb->vb2_queue->allow_zero_bytesused) |
| pdst->bytesused = psrc->bytesused; |
| else |
| pdst->bytesused = psrc->bytesused ? |
| psrc->bytesused : pdst->length; |
| pdst->data_offset = psrc->data_offset; |
| } |
| } |
| } else { |
| /* |
| * Single-planar buffers do not use planes array, |
| * so fill in relevant v4l2_buffer struct fields instead. |
| * In videobuf we use our internal V4l2_planes struct for |
| * single-planar buffers as well, for simplicity. |
| * |
| * If bytesused == 0 for the output buffer, then fall back |
| * to the full buffer size as that's a sensible default. |
| * |
| * Some drivers, e.g. old codec drivers, use bytesused == 0 as |
| * a way to indicate that streaming is finished. In that case, |
| * the driver should use the allow_zero_bytesused flag to keep |
| * old userspace applications working. |
| */ |
| if (b->memory == VB2_MEMORY_USERPTR) { |
| planes[0].m.userptr = b->m.userptr; |
| planes[0].length = b->length; |
| } |
| |
| if (b->memory == VB2_MEMORY_DMABUF) { |
| planes[0].m.fd = b->m.fd; |
| planes[0].length = b->length; |
| } |
| |
| if (V4L2_TYPE_IS_OUTPUT(b->type)) { |
| if (b->bytesused == 0) |
| vb2_warn_zero_bytesused(vb); |
| |
| if (vb->vb2_queue->allow_zero_bytesused) |
| planes[0].bytesused = b->bytesused; |
| else |
| planes[0].bytesused = b->bytesused ? |
| b->bytesused : planes[0].length; |
| } else |
| planes[0].bytesused = 0; |
| |
| } |
| |
| /* Zero flags that the vb2 core handles */ |
| vbuf->flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS; |
| if (!vb->vb2_queue->copy_timestamp || !V4L2_TYPE_IS_OUTPUT(b->type)) { |
| /* |
| * Non-COPY timestamps and non-OUTPUT queues will get |
| * their timestamp and timestamp source flags from the |
| * queue. |
| */ |
| vbuf->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK; |
| } |
| |
| if (V4L2_TYPE_IS_OUTPUT(b->type)) { |
| /* |
| * For output buffers mask out the timecode flag: |
| * this will be handled later in vb2_internal_qbuf(). |
| * The 'field' is valid metadata for this output buffer |
| * and so that needs to be copied here. |
| */ |
| vbuf->flags &= ~V4L2_BUF_FLAG_TIMECODE; |
| vbuf->field = b->field; |
| } else { |
| /* Zero any output buffer flags as this is a capture buffer */ |
| vbuf->flags &= ~V4L2_BUFFER_OUT_FLAGS; |
| } |
| |
| return 0; |
| } |
| |
| static const struct vb2_buf_ops v4l2_buf_ops = { |
| .fill_user_buffer = __fill_v4l2_buffer, |
| .fill_vb2_buffer = __fill_vb2_buffer, |
| .copy_timestamp = __copy_timestamp, |
| }; |
| |
| /** |
| * vb2_querybuf() - query video buffer information |
| * @q: videobuf queue |
| * @b: buffer struct passed from userspace to vidioc_querybuf handler |
| * in driver |
| * |
| * Should be called from vidioc_querybuf ioctl handler in driver. |
| * This function will verify the passed v4l2_buffer structure and fill the |
| * relevant information for the userspace. |
| * |
| * The return values from this function are intended to be directly returned |
| * from vidioc_querybuf handler in driver. |
| */ |
| int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b) |
| { |
| struct vb2_buffer *vb; |
| int ret; |
| |
| if (b->type != q->type) { |
| dprintk(1, "wrong buffer type\n"); |
| return -EINVAL; |
| } |
| |
| if (b->index >= q->num_buffers) { |
| dprintk(1, "buffer index out of range\n"); |
| return -EINVAL; |
| } |
| vb = q->bufs[b->index]; |
| ret = __verify_planes_array(vb, b); |
| if (!ret) |
| vb2_core_querybuf(q, b->index, b); |
| return ret; |
| } |
| EXPORT_SYMBOL(vb2_querybuf); |
| |
| /** |
| * vb2_reqbufs() - Wrapper for vb2_core_reqbufs() that also verifies |
| * the memory and type values. |
| * @q: videobuf2 queue |
| * @req: struct passed from userspace to vidioc_reqbufs handler |
| * in driver |
| */ |
| int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) |
| { |
| int ret = vb2_verify_memory_type(q, req->memory, req->type); |
| |
| return ret ? ret : vb2_core_reqbufs(q, req->memory, &req->count); |
| } |
| EXPORT_SYMBOL_GPL(vb2_reqbufs); |
| |
| /** |
| * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel |
| * @q: videobuf2 queue |
| * @b: buffer structure passed from userspace to vidioc_prepare_buf |
| * handler in driver |
| * |
| * Should be called from vidioc_prepare_buf ioctl handler of a driver. |
| * This function: |
| * 1) verifies the passed buffer, |
| * 2) calls buf_prepare callback in the driver (if provided), in which |
| * driver-specific buffer initialization can be performed, |
| * |
| * The return values from this function are intended to be directly returned |
| * from vidioc_prepare_buf handler in driver. |
| */ |
| int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b) |
| { |
| int ret; |
| |
| if (vb2_fileio_is_active(q)) { |
| dprintk(1, "file io in progress\n"); |
| return -EBUSY; |
| } |
| |
| ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf"); |
| |
| return ret ? ret : vb2_core_prepare_buf(q, b->index, b); |
| } |
| EXPORT_SYMBOL_GPL(vb2_prepare_buf); |
| |
| /** |
| * vb2_create_bufs() - Wrapper for vb2_core_create_bufs() that also verifies |
| * the memory and type values. |
| * @q: videobuf2 queue |
| * @create: creation parameters, passed from userspace to vidioc_create_bufs |
| * handler in driver |
| */ |
| int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) |
| { |
| unsigned requested_planes = 1; |
| unsigned requested_sizes[VIDEO_MAX_PLANES]; |
| struct v4l2_format *f = &create->format; |
| int ret = vb2_verify_memory_type(q, create->memory, f->type); |
| unsigned i; |
| |
| create->index = q->num_buffers; |
| if (create->count == 0) |
| return ret != -EBUSY ? ret : 0; |
| |
| switch (f->type) { |
| case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE: |
| case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE: |
| requested_planes = f->fmt.pix_mp.num_planes; |
| if (requested_planes == 0 || |
| requested_planes > VIDEO_MAX_PLANES) |
| return -EINVAL; |
| for (i = 0; i < requested_planes; i++) |
| requested_sizes[i] = |
| f->fmt.pix_mp.plane_fmt[i].sizeimage; |
| break; |
| case V4L2_BUF_TYPE_VIDEO_CAPTURE: |
| case V4L2_BUF_TYPE_VIDEO_OUTPUT: |
| requested_sizes[0] = f->fmt.pix.sizeimage; |
| break; |
| case V4L2_BUF_TYPE_VBI_CAPTURE: |
| case V4L2_BUF_TYPE_VBI_OUTPUT: |
| requested_sizes[0] = f->fmt.vbi.samples_per_line * |
| (f->fmt.vbi.count[0] + f->fmt.vbi.count[1]); |
| break; |
| case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE: |
| case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT: |
| requested_sizes[0] = f->fmt.sliced.io_size; |
| break; |
| case V4L2_BUF_TYPE_SDR_CAPTURE: |
| case V4L2_BUF_TYPE_SDR_OUTPUT: |
| requested_sizes[0] = f->fmt.sdr.buffersize; |
| break; |
| default: |
| return -EINVAL; |
| } |
| for (i = 0; i < requested_planes; i++) |
| if (requested_sizes[i] == 0) |
| return -EINVAL; |
| return ret ? ret : vb2_core_create_bufs(q, create->memory, |
| &create->count, requested_planes, requested_sizes); |
| } |
| EXPORT_SYMBOL_GPL(vb2_create_bufs); |
| |
| static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b) |
| { |
| int ret = vb2_queue_or_prepare_buf(q, b, "qbuf"); |
| |
| return ret ? ret : vb2_core_qbuf(q, b->index, b); |
| } |
| |
| /** |
| * vb2_qbuf() - Queue a buffer from userspace |
| * @q: videobuf2 queue |
| * @b: buffer structure passed from userspace to vidioc_qbuf handler |
| * in driver |
| * |
| * Should be called from vidioc_qbuf ioctl handler of a driver. |
| * This function: |
| * 1) verifies the passed buffer, |
| * 2) if necessary, calls buf_prepare callback in the driver (if provided), in |
| * which driver-specific buffer initialization can be performed, |
| * 3) if streaming is on, queues the buffer in driver by the means of buf_queue |
| * callback for processing. |
| * |
| * The return values from this function are intended to be directly returned |
| * from vidioc_qbuf handler in driver. |
| */ |
| int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b) |
| { |
| if (vb2_fileio_is_active(q)) { |
| dprintk(1, "file io in progress\n"); |
| return -EBUSY; |
| } |
| |
| return vb2_internal_qbuf(q, b); |
| } |
| EXPORT_SYMBOL_GPL(vb2_qbuf); |
| |
| static int vb2_internal_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, |
| bool nonblocking) |
| { |
| int ret; |
| |
| if (b->type != q->type) { |
| dprintk(1, "invalid buffer type\n"); |
| return -EINVAL; |
| } |
| |
| ret = vb2_core_dqbuf(q, NULL, b, nonblocking); |
| |
| return ret; |
| } |
| |
| /** |
| * vb2_dqbuf() - Dequeue a buffer to the userspace |
| * @q: videobuf2 queue |
| * @b: buffer structure passed from userspace to vidioc_dqbuf handler |
| * in driver |
| * @nonblocking: if true, this call will not sleep waiting for a buffer if no |
| * buffers ready for dequeuing are present. Normally the driver |
| * would be passing (file->f_flags & O_NONBLOCK) here |
| * |
| * Should be called from vidioc_dqbuf ioctl handler of a driver. |
| * This function: |
| * 1) verifies the passed buffer, |
| * 2) calls buf_finish callback in the driver (if provided), in which |
| * driver can perform any additional operations that may be required before |
| * returning the buffer to userspace, such as cache sync, |
| * 3) the buffer struct members are filled with relevant information for |
| * the userspace. |
| * |
| * The return values from this function are intended to be directly returned |
| * from vidioc_dqbuf handler in driver. |
| */ |
| int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking) |
| { |
| if (vb2_fileio_is_active(q)) { |
| dprintk(1, "file io in progress\n"); |
| return -EBUSY; |
| } |
| return vb2_internal_dqbuf(q, b, nonblocking); |
| } |
| EXPORT_SYMBOL_GPL(vb2_dqbuf); |
| |
| /** |
| * vb2_streamon - start streaming |
| * @q: videobuf2 queue |
| * @type: type argument passed from userspace to vidioc_streamon handler |
| * |
| * Should be called from vidioc_streamon handler of a driver. |
| * This function: |
| * 1) verifies current state |
| * 2) passes any previously queued buffers to the driver and starts streaming |
| * |
| * The return values from this function are intended to be directly returned |
| * from vidioc_streamon handler in the driver. |
| */ |
| int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type) |
| { |
| if (vb2_fileio_is_active(q)) { |
| dprintk(1, "file io in progress\n"); |
| return -EBUSY; |
| } |
| return vb2_core_streamon(q, type); |
| } |
| EXPORT_SYMBOL_GPL(vb2_streamon); |
| |
| /** |
| * vb2_streamoff - stop streaming |
| * @q: videobuf2 queue |
| * @type: type argument passed from userspace to vidioc_streamoff handler |
| * |
| * Should be called from vidioc_streamoff handler of a driver. |
| * This function: |
| * 1) verifies current state, |
| * 2) stop streaming and dequeues any queued buffers, including those previously |
| * passed to the driver (after waiting for the driver to finish). |
| * |
| * This call can be used for pausing playback. |
| * The return values from this function are intended to be directly returned |
| * from vidioc_streamoff handler in the driver |
| */ |
| int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type) |
| { |
| if (vb2_fileio_is_active(q)) { |
| dprintk(1, "file io in progress\n"); |
| return -EBUSY; |
| } |
| return vb2_core_streamoff(q, type); |
| } |
| EXPORT_SYMBOL_GPL(vb2_streamoff); |
| |
| /** |
| * vb2_expbuf() - Export a buffer as a file descriptor |
| * @q: videobuf2 queue |
| * @eb: export buffer structure passed from userspace to vidioc_expbuf |
| * handler in driver |
| * |
| * The return values from this function are intended to be directly returned |
| * from vidioc_expbuf handler in driver. |
| */ |
| int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb) |
| { |
| return vb2_core_expbuf(q, &eb->fd, eb->type, eb->index, |
| eb->plane, eb->flags); |
| } |
| EXPORT_SYMBOL_GPL(vb2_expbuf); |
| |
| /** |
| * vb2_queue_init() - initialize a videobuf2 queue |
| * @q: videobuf2 queue; this structure should be allocated in driver |
| * |
| * The vb2_queue structure should be allocated by the driver. The driver is |
| * responsible of clearing it's content and setting initial values for some |
| * required entries before calling this function. |
| * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer |
| * to the struct vb2_queue description in include/media/videobuf2-core.h |
| * for more information. |
| */ |
| int vb2_queue_init(struct vb2_queue *q) |
| { |
| /* |
| * Sanity check |
| */ |
| if (WARN_ON(!q) || |
| WARN_ON(q->timestamp_flags & |
| ~(V4L2_BUF_FLAG_TIMESTAMP_MASK | |
| V4L2_BUF_FLAG_TSTAMP_SRC_MASK))) |
| return -EINVAL; |
| |
| /* Warn that the driver should choose an appropriate timestamp type */ |
| WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) == |
| V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN); |
| |
| /* Warn that vb2_memory should match with v4l2_memory */ |
| if (WARN_ON(VB2_MEMORY_MMAP != (int)V4L2_MEMORY_MMAP) |
| || WARN_ON(VB2_MEMORY_USERPTR != (int)V4L2_MEMORY_USERPTR) |
| || WARN_ON(VB2_MEMORY_DMABUF != (int)V4L2_MEMORY_DMABUF)) |
| return -EINVAL; |
| |
| if (q->buf_struct_size == 0) |
| q->buf_struct_size = sizeof(struct vb2_v4l2_buffer); |
| |
| q->buf_ops = &v4l2_buf_ops; |
| q->is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type); |
| q->is_output = V4L2_TYPE_IS_OUTPUT(q->type); |
| q->copy_timestamp = (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) |
| == V4L2_BUF_FLAG_TIMESTAMP_COPY; |
| /* |
| * For compatibility with vb1: if QBUF hasn't been called yet, then |
| * return POLLERR as well. This only affects capture queues, output |
| * queues will always initialize waiting_for_buffers to false. |
| */ |
| q->quirk_poll_must_check_waiting_for_buffers = true; |
| |
| return vb2_core_queue_init(q); |
| } |
| EXPORT_SYMBOL_GPL(vb2_queue_init); |
| |
| /** |
| * vb2_queue_release() - stop streaming, release the queue and free memory |
| * @q: videobuf2 queue |
| * |
| * This function stops streaming and performs necessary clean ups, including |
| * freeing video buffer memory. The driver is responsible for freeing |
| * the vb2_queue structure itself. |
| */ |
| void vb2_queue_release(struct vb2_queue *q) |
| { |
| vb2_core_queue_release(q); |
| } |
| EXPORT_SYMBOL_GPL(vb2_queue_release); |
| |
| /** |
| * vb2_poll() - implements poll userspace operation |
| * @q: videobuf2 queue |
| * @file: file argument passed to the poll file operation handler |
| * @wait: wait argument passed to the poll file operation handler |
| * |
| * This function implements poll file operation handler for a driver. |
| * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will |
| * be informed that the file descriptor of a video device is available for |
| * reading. |
| * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor |
| * will be reported as available for writing. |
| * |
| * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any |
| * pending events. |
| * |
| * The return values from this function are intended to be directly returned |
| * from poll handler in driver. |
| */ |
| unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait) |
| { |
| struct video_device *vfd = video_devdata(file); |
| unsigned long req_events = poll_requested_events(wait); |
| unsigned int res = 0; |
| |
| if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) { |
| struct v4l2_fh *fh = file->private_data; |
| |
| if (v4l2_event_pending(fh)) |
| res = POLLPRI; |
| else if (req_events & POLLPRI) |
| poll_wait(file, &fh->wait, wait); |
| } |
| |
| return res | vb2_core_poll(q, file, wait); |
| } |
| EXPORT_SYMBOL_GPL(vb2_poll); |
| |
| /* |
| * The following functions are not part of the vb2 core API, but are helper |
| * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations |
| * and struct vb2_ops. |
| * They contain boilerplate code that most if not all drivers have to do |
| * and so they simplify the driver code. |
| */ |
| |
| /* The queue is busy if there is a owner and you are not that owner. */ |
| static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file) |
| { |
| return vdev->queue->owner && vdev->queue->owner != file->private_data; |
| } |
| |
| /* vb2 ioctl helpers */ |
| |
| int vb2_ioctl_reqbufs(struct file *file, void *priv, |
| struct v4l2_requestbuffers *p) |
| { |
| struct video_device *vdev = video_devdata(file); |
| int res = vb2_verify_memory_type(vdev->queue, p->memory, p->type); |
| |
| if (res) |
| return res; |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| res = vb2_core_reqbufs(vdev->queue, p->memory, &p->count); |
| /* If count == 0, then the owner has released all buffers and he |
| is no longer owner of the queue. Otherwise we have a new owner. */ |
| if (res == 0) |
| vdev->queue->owner = p->count ? file->private_data : NULL; |
| return res; |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs); |
| |
| int vb2_ioctl_create_bufs(struct file *file, void *priv, |
| struct v4l2_create_buffers *p) |
| { |
| struct video_device *vdev = video_devdata(file); |
| int res = vb2_verify_memory_type(vdev->queue, p->memory, |
| p->format.type); |
| |
| p->index = vdev->queue->num_buffers; |
| /* |
| * If count == 0, then just check if memory and type are valid. |
| * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0. |
| */ |
| if (p->count == 0) |
| return res != -EBUSY ? res : 0; |
| if (res) |
| return res; |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| |
| res = vb2_create_bufs(vdev->queue, p); |
| if (res == 0) |
| vdev->queue->owner = file->private_data; |
| return res; |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs); |
| |
| int vb2_ioctl_prepare_buf(struct file *file, void *priv, |
| struct v4l2_buffer *p) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| return vb2_prepare_buf(vdev->queue, p); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf); |
| |
| int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| /* No need to call vb2_queue_is_busy(), anyone can query buffers. */ |
| return vb2_querybuf(vdev->queue, p); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf); |
| |
| int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| return vb2_qbuf(vdev->queue, p); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf); |
| |
| int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf); |
| |
| int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| return vb2_streamon(vdev->queue, i); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_streamon); |
| |
| int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| return vb2_streamoff(vdev->queue, i); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff); |
| |
| int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| return vb2_expbuf(vdev->queue, p); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf); |
| |
| /* v4l2_file_operations helpers */ |
| |
| int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| return vb2_mmap(vdev->queue, vma); |
| } |
| EXPORT_SYMBOL_GPL(vb2_fop_mmap); |
| |
| int _vb2_fop_release(struct file *file, struct mutex *lock) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| if (lock) |
| mutex_lock(lock); |
| if (file->private_data == vdev->queue->owner) { |
| vb2_queue_release(vdev->queue); |
| vdev->queue->owner = NULL; |
| } |
| if (lock) |
| mutex_unlock(lock); |
| return v4l2_fh_release(file); |
| } |
| EXPORT_SYMBOL_GPL(_vb2_fop_release); |
| |
| int vb2_fop_release(struct file *file) |
| { |
| struct video_device *vdev = video_devdata(file); |
| struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; |
| |
| return _vb2_fop_release(file, lock); |
| } |
| EXPORT_SYMBOL_GPL(vb2_fop_release); |
| |
| ssize_t vb2_fop_write(struct file *file, const char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| struct video_device *vdev = video_devdata(file); |
| struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; |
| int err = -EBUSY; |
| |
| if (!(vdev->queue->io_modes & VB2_WRITE)) |
| return -EINVAL; |
| if (lock && mutex_lock_interruptible(lock)) |
| return -ERESTARTSYS; |
| if (vb2_queue_is_busy(vdev, file)) |
| goto exit; |
| err = vb2_write(vdev->queue, buf, count, ppos, |
| file->f_flags & O_NONBLOCK); |
| if (vdev->queue->fileio) |
| vdev->queue->owner = file->private_data; |
| exit: |
| if (lock) |
| mutex_unlock(lock); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(vb2_fop_write); |
| |
| ssize_t vb2_fop_read(struct file *file, char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| struct video_device *vdev = video_devdata(file); |
| struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; |
| int err = -EBUSY; |
| |
| if (!(vdev->queue->io_modes & VB2_READ)) |
| return -EINVAL; |
| if (lock && mutex_lock_interruptible(lock)) |
| return -ERESTARTSYS; |
| if (vb2_queue_is_busy(vdev, file)) |
| goto exit; |
| err = vb2_read(vdev->queue, buf, count, ppos, |
| file->f_flags & O_NONBLOCK); |
| if (vdev->queue->fileio) |
| vdev->queue->owner = file->private_data; |
| exit: |
| if (lock) |
| mutex_unlock(lock); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(vb2_fop_read); |
| |
| unsigned int vb2_fop_poll(struct file *file, poll_table *wait) |
| { |
| struct video_device *vdev = video_devdata(file); |
| struct vb2_queue *q = vdev->queue; |
| struct mutex *lock = q->lock ? q->lock : vdev->lock; |
| unsigned res; |
| void *fileio; |
| |
| /* |
| * If this helper doesn't know how to lock, then you shouldn't be using |
| * it but you should write your own. |
| */ |
| WARN_ON(!lock); |
| |
| if (lock && mutex_lock_interruptible(lock)) |
| return POLLERR; |
| |
| fileio = q->fileio; |
| |
| res = vb2_poll(vdev->queue, file, wait); |
| |
| /* If fileio was started, then we have a new queue owner. */ |
| if (!fileio && q->fileio) |
| q->owner = file->private_data; |
| if (lock) |
| mutex_unlock(lock); |
| return res; |
| } |
| EXPORT_SYMBOL_GPL(vb2_fop_poll); |
| |
| #ifndef CONFIG_MMU |
| unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr, |
| unsigned long len, unsigned long pgoff, unsigned long flags) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags); |
| } |
| EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area); |
| #endif |
| |
| /* vb2_ops helpers. Only use if vq->lock is non-NULL. */ |
| |
| void vb2_ops_wait_prepare(struct vb2_queue *vq) |
| { |
| mutex_unlock(vq->lock); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare); |
| |
| void vb2_ops_wait_finish(struct vb2_queue *vq) |
| { |
| mutex_lock(vq->lock); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ops_wait_finish); |
| |
| MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2"); |
| MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski"); |
| MODULE_LICENSE("GPL"); |