diff options
Diffstat (limited to 'drivers/media/video/videobuf2-core.c')
| -rw-r--r-- | drivers/media/video/videobuf2-core.c | 1819 |
1 files changed, 1819 insertions, 0 deletions
diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c new file mode 100644 index 000000000000..6698c77e0f64 --- /dev/null +++ b/drivers/media/video/videobuf2-core.c @@ -0,0 +1,1819 @@ +/* + * videobuf2-core.c - V4L2 driver helper framework + * + * Copyright (C) 2010 Samsung Electronics + * + * Author: Pawel Osciak <pawel@osciak.com> + * Marek Szyprowski <m.szyprowski@samsung.com> + * + * 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 <media/videobuf2-core.h> + +static int debug; +module_param(debug, int, 0644); + +#define dprintk(level, fmt, arg...) \ + do { \ + if (debug >= level) \ + printk(KERN_DEBUG "vb2: " fmt, ## arg); \ + } while (0) + +#define call_memop(q, plane, op, args...) \ + (((q)->mem_ops->op) ? \ + ((q)->mem_ops->op(args)) : 0) + +#define call_qop(q, op, args...) \ + (((q)->ops->op) ? ((q)->ops->op(args)) : 0) + +/** + * __vb2_buf_mem_alloc() - allocate video memory for the given buffer + */ +static int __vb2_buf_mem_alloc(struct vb2_buffer *vb, + unsigned long *plane_sizes) +{ + struct vb2_queue *q = vb->vb2_queue; + void *mem_priv; + int plane; + + /* Allocate memory for all planes in this buffer */ + for (plane = 0; plane < vb->num_planes; ++plane) { + mem_priv = call_memop(q, plane, alloc, q->alloc_ctx[plane], + plane_sizes[plane]); + if (!mem_priv) + goto free; + + /* Associate allocator private data with this plane */ + vb->planes[plane].mem_priv = mem_priv; + vb->v4l2_planes[plane].length = plane_sizes[plane]; + } + + return 0; +free: + /* Free already allocated memory if one of the allocations failed */ + for (; plane > 0; --plane) + call_memop(q, plane, put, vb->planes[plane - 1].mem_priv); + + return -ENOMEM; +} + +/** + * __vb2_buf_mem_free() - free memory of the given buffer + */ +static void __vb2_buf_mem_free(struct vb2_buffer *vb) +{ + struct vb2_queue *q = vb->vb2_queue; + unsigned int plane; + + for (plane = 0; plane < vb->num_planes; ++plane) { + call_memop(q, plane, put, vb->planes[plane].mem_priv); + vb->planes[plane].mem_priv = NULL; + dprintk(3, "Freed plane %d of buffer %d\n", + plane, vb->v4l2_buf.index); + } +} + +/** + * __vb2_buf_userptr_put() - release userspace memory associated with + * a USERPTR buffer + */ +static void __vb2_buf_userptr_put(struct vb2_buffer *vb) +{ + struct vb2_queue *q = vb->vb2_queue; + unsigned int plane; + + for (plane = 0; plane < vb->num_planes; ++plane) { + void *mem_priv = vb->planes[plane].mem_priv; + + if (mem_priv) { + call_memop(q, plane, put_userptr, mem_priv); + vb->planes[plane].mem_priv = NULL; + } + } +} + +/** + * __setup_offsets() - setup unique offsets ("cookies") for every plane in + * every buffer on the queue + */ +static void __setup_offsets(struct vb2_queue *q) +{ + unsigned int buffer, plane; + struct vb2_buffer *vb; + unsigned long off = 0; + + for (buffer = 0; buffer < q->num_buffers; ++buffer) { + vb = q->bufs[buffer]; + if (!vb) + continue; + + for (plane = 0; plane < vb->num_planes; ++plane) { + vb->v4l2_planes[plane].m.mem_offset = off; + + dprintk(3, "Buffer %d, plane %d offset 0x%08lx\n", + buffer, plane, off); + + off += vb->v4l2_planes[plane].length; + off = PAGE_ALIGN(off); + } + } +} + +/** + * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type) + * video buffer memory for all buffers/planes on the queue and initializes the + * queue + * + * Returns the number of buffers successfully allocated. + */ +static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory, + unsigned int num_buffers, unsigned int num_planes, + unsigned long plane_sizes[]) +{ + unsigned int buffer; + struct vb2_buffer *vb; + int ret; + + for (buffer = 0; buffer < num_buffers; ++buffer) { + /* Allocate videobuf buffer structures */ + vb = kzalloc(q->buf_struct_size, GFP_KERNEL); + if (!vb) { + dprintk(1, "Memory alloc for buffer struct failed\n"); + break; + } + + /* Length stores number of planes for multiplanar buffers */ + if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) + vb->v4l2_buf.length = num_planes; + + vb->state = VB2_BUF_STATE_DEQUEUED; + vb->vb2_queue = q; + vb->num_planes = num_planes; + vb->v4l2_buf.index = buffer; + vb->v4l2_buf.type = q->type; + vb->v4l2_buf.memory = memory; + + /* Allocate video buffer memory for the MMAP type */ + if (memory == V4L2_MEMORY_MMAP) { + ret = __vb2_buf_mem_alloc(vb, plane_sizes); + if (ret) { + dprintk(1, "Failed allocating memory for " + "buffer %d\n", buffer); + kfree(vb); + break; + } + /* + * Call the driver-provided buffer initialization + * callback, if given. An error in initialization + * results in queue setup failure. + */ + ret = call_qop(q, buf_init, vb); + if (ret) { + dprintk(1, "Buffer %d %p initialization" + " failed\n", buffer, vb); + __vb2_buf_mem_free(vb); + kfree(vb); + break; + } + } + + q->bufs[buffer] = vb; + } + + q->num_buffers = buffer; + + __setup_offsets(q); + + dprintk(1, "Allocated %d buffers, %d plane(s) each\n", + q->num_buffers, num_planes); + + return buffer; +} + +/** + * __vb2_free_mem() - release all video buffer memory for a given queue + */ +static void __vb2_free_mem(struct vb2_queue *q) +{ + unsigned int buffer; + struct vb2_buffer *vb; + + for (buffer = 0; buffer < q->num_buffers; ++buffer) { + vb = q->bufs[buffer]; + if (!vb) + continue; + + /* Free MMAP buffers or release USERPTR buffers */ + if (q->memory == V4L2_MEMORY_MMAP) + __vb2_buf_mem_free(vb); + else + __vb2_buf_userptr_put(vb); + } +} + +/** + * __vb2_queue_free() - free the queue - video memory and related information + * and return the queue to an uninitialized state. Might be called even if the + * queue has already been freed. + */ +static void __vb2_queue_free(struct vb2_queue *q) +{ + unsigned int buffer; + + /* Call driver-provided cleanup function for each buffer, if provided */ + if (q->ops->buf_cleanup) { + for (buffer = 0; buffer < q->num_buffers; ++buffer) { + if (NULL == q->bufs[buffer]) + continue; + q->ops->buf_cleanup(q->bufs[buffer]); + } + } + + /* Release video buffer memory */ + __vb2_free_mem(q); + + /* Free videobuf buffers */ + for (buffer = 0; buffer < q->num_buffers; ++buffer) { + kfree(q->bufs[buffer]); + q->bufs[buffer] = NULL; + } + + q->num_buffers = 0; + q->memory = 0; +} + +/** + * __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, struct v4l2_buffer *b) +{ + /* Is memory for copying plane information present? */ + if (NULL == b->m.planes) { + dprintk(1, "Multi-planar buffer passed but " + "planes array not provided\n"); + return -EINVAL; + } + + if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) { + dprintk(1, "Incorrect planes array length, " + "expected %d, got %d\n", vb->num_planes, b->length); + return -EINVAL; + } + + return 0; +} + +/** + * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be + * returned to userspace + */ +static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b) +{ + struct vb2_queue *q = vb->vb2_queue; + int ret = 0; + + /* Copy back data such as timestamp, input, etc. */ + memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m)); + b->input = vb->v4l2_buf.input; + b->reserved = vb->v4l2_buf.reserved; + + if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) { + ret = __verify_planes_array(vb, b); + if (ret) + return ret; + + /* + * Fill in plane-related data if userspace provided an array + * for it. The memory and size is verified above. + */ + memcpy(b->m.planes, vb->v4l2_planes, + b->length * sizeof(struct v4l2_plane)); + } else { + /* + * We use length and offset in v4l2_planes array even for + * single-planar buffers, but userspace does not. + */ + b->length = vb->v4l2_planes[0].length; + b->bytesused = vb->v4l2_planes[0].bytesused; + if (q->memory == V4L2_MEMORY_MMAP) + b->m.offset = vb->v4l2_planes[0].m.mem_offset; + else if (q->memory == V4L2_MEMORY_USERPTR) + b->m.userptr = vb->v4l2_planes[0].m.userptr; + } + + b->flags = 0; + + 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_DEQUEUED: + /* nothing */ + break; + } + + if (vb->num_planes_mapped == vb->num_planes) + b->flags |= V4L2_BUF_FLAG_MAPPED; + + return ret; +} + +/** + * 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; + + if (b->type != q->type) { + dprintk(1, "querybuf: wrong buffer type\n"); + return -EINVAL; + } + + if (b->index >= q->num_buffers) { + dprintk(1, "querybuf: buffer index out of range\n"); + return -EINVAL; + } + vb = q->bufs[b->index]; + + return __fill_v4l2_buffer(vb, b); +} +EXPORT_SYMBOL(vb2_querybuf); + +/** + * __verify_userptr_ops() - verify that all memory operations required for + * USERPTR queue type have been provided + */ +static int __verify_userptr_ops(struct vb2_queue *q) +{ + if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr || + !q->mem_ops->put_userptr) + return -EINVAL; + + return 0; +} + +/** + * __verify_mmap_ops() - verify that all memory operations required for + * MMAP queue type have been provided + */ +static int __verify_mmap_ops(struct vb2_queue *q) +{ + if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc || + !q->mem_ops->put || !q->mem_ops->mmap) + return -EINVAL; + + return 0; +} + +/** + * __buffers_in_use() - return true if any buffers on the queue are in use and + * the queue cannot be freed (by the means of REQBUFS(0)) call + */ +static bool __buffers_in_use(struct vb2_queue *q) +{ + unsigned int buffer, plane; + struct vb2_buffer *vb; + + for (buffer = 0; buffer < q->num_buffers; ++buffer) { + vb = q->bufs[buffer]; + for (plane = 0; plane < vb->num_planes; ++plane) { + /* + * If num_users() has not been provided, call_memop + * will return 0, apparently nobody cares about this + * case anyway. If num_users() returns more than 1, + * we are not the only user of the plane's memory. + */ + if (call_memop(q, plane, num_users, + vb->planes[plane].mem_priv) > 1) + return true; + } + } + + return false; +} + +/** + * vb2_reqbufs() - Initiate streaming + * @q: videobuf2 queue + * @req: struct passed from userspace to vidioc_reqbufs handler in driver + * + * Should be called from vidioc_reqbufs ioctl handler of a driver. + * This function: + * 1) verifies streaming parameters passed from the userspace, + * 2) sets up the queue, + * 3) negotiates number of buffers and planes per buffer with the driver + * to be used during streaming, + * 4) allocates internal buffer structures (struct vb2_buffer), according to + * the agreed parameters, + * 5) for MMAP memory type, allocates actual video memory, using the + * memory handling/allocation routines provided during queue initialization + * + * If req->count is 0, all the memory will be freed instead. + * If the queue has been allocated previously (by a previous vb2_reqbufs) call + * and the queue is not busy, memory will be reallocated. + * + * The return values from this function are intended to be directly returned + * from vidioc_reqbufs handler in driver. + */ +int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) +{ + unsigned int num_buffers, num_planes; + unsigned long plane_sizes[VIDEO_MAX_PLANES]; + int ret = 0; + + if (q->fileio) { + dprintk(1, "reqbufs: file io in progress\n"); + return -EBUSY; + } + + if (req->memory != V4L2_MEMORY_MMAP + && req->memory != V4L2_MEMORY_USERPTR) { + dprintk(1, "reqbufs: unsupported memory type\n"); + return -EINVAL; + } + + if (req->type != q->type) { + dprintk(1, "reqbufs: requested type is incorrect\n"); + return -EINVAL; + } + + if (q->streaming) { + dprintk(1, "reqbufs: streaming active\n"); + return -EBUSY; + } + + /* + * Make sure all the required memory ops for given memory type + * are available. + */ + if (req->memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) { + dprintk(1, "reqbufs: MMAP for current setup unsupported\n"); + return -EINVAL; + } + + if (req->memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) { + dprintk(1, "reqbufs: USERPTR for current setup unsupported\n"); + return -EINVAL; + } + + /* + * If the same number of buffers and memory access method is requested + * then return immediately. + */ + if (q->memory == req->memory && req->count == q->num_buffers) + return 0; + + if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) { + /* + * We already have buffers allocated, so first check if they + * are not in use and can be freed. + */ + if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) { + dprintk(1, "reqbufs: memory in use, cannot free\n"); + return -EBUSY; + } + + __vb2_queue_free(q); + + /* + * In case of REQBUFS(0) return immediately without calling + * driver's queue_setup() callback and allocating resources. + */ + if (req->count == 0) + return 0; + } + + /* + * Make sure the requested values and current defaults are sane. + */ + num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME); + memset(plane_sizes, 0, sizeof(plane_sizes)); + memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx)); + + /* + * Ask the driver how many buffers and planes per buffer it requires. + * Driver also sets the size and allocator context for each plane. + */ + ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes, + plane_sizes, q->alloc_ctx); + if (ret) + return ret; + + /* Finally, allocate buffers and video memory */ + ret = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes, + plane_sizes); + if (ret < 0) { + dprintk(1, "Memory allocation failed with error: %d\n", ret); + return ret; + } + + /* + * Check if driver can handle the allocated number of buffers. + */ + if (ret < num_buffers) { + unsigned int orig_num_buffers; + + orig_num_buffers = num_buffers = ret; + ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes, + plane_sizes, q->alloc_ctx); + if (ret) + goto free_mem; + + if (orig_num_buffers < num_buffers) { + ret = -ENOMEM; + goto free_mem; + } + + /* + * Ok, driver accepted smaller number of buffers. + */ + ret = num_buffers; + } + + q->memory = req->memory; + + /* + * Return the number of successfully allocated buffers + * to the userspace. + */ + req->count = ret; + + return 0; + +free_mem: + __vb2_queue_free(q); + return ret; +} +EXPORT_SYMBOL_GPL(vb2_reqbufs); + +/** + * vb2_plane_vaddr() - Return a kernel virtual address of a given plane + * @vb: vb2_buffer to which the plane in question belongs to + * @plane_no: plane number for which the address is to be returned + * + * This function returns a kernel virtual address of a given plane if + * such a mapping exist, NULL otherwise. + */ +void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no) +{ + struct vb2_queue *q = vb->vb2_queue; + + if (plane_no > vb->num_planes) + return NULL; + + return call_memop(q, plane_no, vaddr, vb->planes[plane_no].mem_priv); + +} +EXPORT_SYMBOL_GPL(vb2_plane_vaddr); + +/** + * vb2_plane_cookie() - Return allocator specific cookie for the given plane + * @vb: vb2_buffer to which the plane in question belongs to + * @plane_no: plane number for which the cookie is to be returned + * + * This function returns an allocator specific cookie for a given plane if + * available, NULL otherwise. The allocator should provide some simple static + * inline function, which would convert this cookie to the allocator specific + * type that can be used directly by the driver to access the buffer. This can + * be for example physical address, pointer to scatter list or IOMMU mapping. + */ +void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no) +{ + struct vb2_queue *q = vb->vb2_queue; + + if (plane_no > vb->num_planes) + return NULL; + + return call_memop(q, plane_no, cookie, vb->planes[plane_no].mem_priv); +} +EXPORT_SYMBOL_GPL(vb2_plane_cookie); + +/** + * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished + * @vb: vb2_buffer returned from the driver + * @state: either VB2_BUF_STATE_DONE if the operation finished successfully + * or VB2_BUF_STATE_ERROR if the operation finished with an error + * + * This function should be called by the driver after a hardware operation on + * a buffer is finished and the buffer may be returned to userspace. The driver + * cannot use this buffer anymore until it is queued back to it by videobuf + * by the means of buf_queue callback. Only buffers previously queued to the + * driver by buf_queue can be passed to this function. + */ +void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state) +{ + struct vb2_queue *q = vb->vb2_queue; + unsigned long flags; + + if (vb->state != VB2_BUF_STATE_ACTIVE) + return; + + if (state != VB2_BUF_STATE_DONE && state != VB2_BUF_STATE_ERROR) + return; + + dprintk(4, "Done processing on buffer %d, state: %d\n", + vb->v4l2_buf.index, vb->state); + + /* Add the buffer to the done buffers list */ + spin_lock_irqsave(&q->done_lock, flags); + vb->state = state; + list_add_tail(&vb->done_entry, &q->done_list); + atomic_dec(&q->queued_count); + spin_unlock_irqrestore(&q->done_lock, flags); + + /* Inform any processes that may be waiting for buffers */ + wake_up(&q->done_wq); +} +EXPORT_SYMBOL_GPL(vb2_buffer_done); + +/** + * __fill_vb2_buffer() - fill a vb2_buffer with information provided in + * a v4l2_buffer by the userspace + */ +static int __fill_vb2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b, + struct v4l2_plane *v4l2_planes) +{ + unsigned int plane; + int ret; + + if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) { + /* + * Verify that the userspace gave us a valid array for + * plane information. + */ + ret = __verify_planes_array(vb, b); + if (ret) + return ret; + + /* 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. + */ + for (plane = 0; plane < vb->num_planes; ++plane) { + v4l2_planes[plane].bytesused = + b->m.planes[plane].bytesused; + v4l2_planes[plane].data_offset = + b->m.planes[plane].data_offset; + } + } + + if (b->memory == V4L2_MEMORY_USERPTR) { + for (plane = 0; plane < vb->num_planes; ++plane) { + v4l2_planes[plane].m.userptr = + b->m.planes[plane].m.userptr; + v4l2_planes[plane].length = + b->m.planes[plane].length; + } + } + } 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 (V4L2_TYPE_IS_OUTPUT(b->type)) + v4l2_planes[0].bytesused = b->bytesused; + + if (b->memory == V4L2_MEMORY_USERPTR) { + v4l2_planes[0].m.userptr = b->m.userptr; + v4l2_planes[0].length = b->length; + } + } + + vb->v4l2_buf.field = b->field; + vb->v4l2_buf.timestamp = b->timestamp; + + return 0; +} + +/** + * __qbuf_userptr() - handle qbuf of a USERPTR buffer + */ +static int __qbuf_userptr(struct vb2_buffer *vb, struct v4l2_buffer *b) +{ + struct v4l2_plane planes[VIDEO_MAX_PLANES]; + struct vb2_queue *q = vb->vb2_queue; + void *mem_priv; + unsigned int plane; + int ret; + int write = !V4L2_TYPE_IS_OUTPUT(q->type); + + /* Verify and copy relevant information provided by the userspace */ + ret = __fill_vb2_buffer(vb, b, planes); + if (ret) + return ret; + + for (plane = 0; plane < vb->num_planes; ++plane) { + /* Skip the plane if already verified */ + if (vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr + && vb->v4l2_planes[plane].length == planes[plane].length) + continue; + + dprintk(3, "qbuf: userspace address for plane %d changed, " + "reacquiring memory\n", plane); + + /* Release previously acquired memory if present */ + if (vb->planes[plane].mem_priv) + call_memop(q, plane, put_userptr, + vb->planes[plane].mem_priv); + + vb->planes[plane].mem_priv = NULL; + + /* Acquire each plane's memory */ + if (q->mem_ops->get_userptr) { + mem_priv = q->mem_ops->get_userptr(q->alloc_ctx[plane], + planes[plane].m.userptr, + planes[plane].length, + write); + if (IS_ERR(mem_priv)) { + dprintk(1, "qbuf: failed acquiring userspace " + "memory for plane %d\n", plane); + ret = PTR_ERR(mem_priv); + goto err; + } + vb->planes[plane].mem_priv = mem_priv; + } + } + + /* + * Call driver-specific initialization on the newly acquired buffer, + * if provided. + */ + ret = call_qop(q, buf_init, vb); + if (ret) { + dprintk(1, "qbuf: buffer initialization failed\n"); + goto err; + } + + /* + * Now that everything is in order, copy relevant information + * provided by userspace. + */ + for (plane = 0; plane < vb->num_planes; ++plane) + vb->v4l2_planes[plane] = planes[plane]; + + return 0; +err: + /* In case of errors, release planes that were already acquired */ + for (; plane > 0; --plane) { + call_memop(q, plane, put_userptr, + vb->planes[plane - 1].mem_priv); + vb->planes[plane - 1].mem_priv = NULL; + } + + return ret; +} + +/** + * __qbuf_mmap() - handle qbuf of an MMAP buffer + */ +static int __qbuf_mmap(struct vb2_buffer *vb, struct v4l2_buffer *b) +{ + return __fill_vb2_buffer(vb, b, vb->v4l2_planes); +} + +/** + * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing + */ +static void __enqueue_in_driver(struct vb2_buffer *vb) +{ + struct vb2_queue *q = vb->vb2_queue; + + vb->state = VB2_BUF_STATE_ACTIVE; + atomic_inc(&q->queued_count); + q->ops->buf_queue(vb); +} + +/** + * 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) 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) +{ + struct vb2_buffer *vb; + int ret = 0; + + if (q->fileio) { + dprintk(1, "qbuf: file io in progress\n"); + return -EBUSY; + } + + if (b->type != q->type) { + dprintk(1, "qbuf: invalid buffer type\n"); + return -EINVAL; + } + + if (b->index >= q->num_buffers) { + dprintk(1, "qbuf: buffer index out of range\n"); + return -EINVAL; + } + + vb = q->bufs[b->index]; + if (NULL == vb) { + /* Should never happen */ + dprintk(1, "qbuf: buffer is NULL\n"); + return -EINVAL; + } + + if (b->memory != q->memory) { + dprintk(1, "qbuf: invalid memory type\n"); + return -EINVAL; + } + + if (vb->state != VB2_BUF_STATE_DEQUEUED) { + dprintk(1, "qbuf: buffer already in use\n"); + return -EINVAL; + } + + if (q->memory == V4L2_MEMORY_MMAP) + ret = __qbuf_mmap(vb, b); + else if (q->memory == V4L2_MEMORY_USERPTR) + ret = __qbuf_userptr(vb, b); + else { + WARN(1, "Invalid queue type\n"); + return -EINVAL; + } + + if (ret) + return ret; + + ret = call_qop(q, buf_prepare, vb); + if (ret) { + dprintk(1, "qbuf: buffer preparation failed\n"); + return ret; + } + + /* + * Add to the queued buffers list, a buffer will stay on it until + * dequeued in dqbuf. + */ + list_add_tail(&vb->queued_entry, &q->queued_list); + vb->state = VB2_BUF_STATE_QUEUED; + + /* + * If already streaming, give the buffer to driver for processing. + * If not, the buffer will be given to driver on next streamon. + */ + if (q->streaming) + __enqueue_in_driver(vb); + + dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index); + return 0; +} +EXPORT_SYMBOL_GPL(vb2_qbuf); + +/** + * __vb2_wait_for_done_vb() - wait for a buffer to become available + * for dequeuing + * + * Will sleep if required for nonblocking == false. + */ +static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking) +{ + /* + * All operations on vb_done_list are performed under done_lock + * spinlock protection. However, buffers may be removed from + * it and returned to userspace only while holding both driver's + * lock and the done_lock spinlock. Thus we can be sure that as + * long as we hold the driver's lock, the list will remain not + * empty if list_empty() check succeeds. + */ + + for (;;) { + int ret; + + if (!q->streaming) { + dprintk(1, "Streaming off, will not wait for buffers\n"); + return -EINVAL; + } + + if (!list_empty(&q->done_list)) { + /* + * Found a buffer that we were waiting for. + */ + break; + } + + if (nonblocking) { + dprintk(1, "Nonblocking and no buffers to dequeue, " + "will not wait\n"); + return -EAGAIN; + } + + /* + * We are streaming and blocking, wait for another buffer to + * become ready or for streamoff. Driver's lock is released to + * allow streamoff or qbuf to be called while waiting. + */ + call_qop(q, wait_prepare, q); + + /* + * All locks have been released, it is safe to sleep now. + */ + dprintk(3, "Will sleep waiting for buffers\n"); + ret = wait_event_interruptible(q->done_wq, + !list_empty(&q->done_list) || !q->streaming); + + /* + * We need to reevaluate both conditions again after reacquiring + * the locks or return an error if one occurred. + */ + call_qop(q, wait_finish, q); + if (ret) + return ret; + } + return 0; +} + +/** + * __vb2_get_done_vb() - get a buffer ready for dequeuing + * + * Will sleep if required for nonblocking == false. + */ +static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb, + int nonblocking) +{ + unsigned long flags; + int ret; + + /* + * Wait for at least one buffer to become available on the done_list. + */ + ret = __vb2_wait_for_done_vb(q, nonblocking); + if (ret) + return ret; + + /* + * Driver's lock has been held since we last verified that done_list + * is not empty, so no need for another list_empty(done_list) check. + */ + spin_lock_irqsave(&q->done_lock, flags); + *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry); + list_del(&(*vb)->done_entry); + spin_unlock_irqrestore(&q->done_lock, flags); + + return 0; +} + +/** + * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2 + * @q: videobuf2 queue + * + * This function will wait until all buffers that have been given to the driver + * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call + * wait_prepare, wait_finish pair. It is intended to be called with all locks + * taken, for example from stop_streaming() callback. + */ +int vb2_wait_for_all_buffers(struct vb2_queue *q) +{ + if (!q->streaming) { + dprintk(1, "Streaming off, will not wait for buffers\n"); + return -EINVAL; + } + + wait_event(q->done_wq, !atomic_read(&q->queued_count)); + return 0; +} +EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers); + +/** + * 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) +{ + struct vb2_buffer *vb = NULL; + int ret; + + if (q->fileio) { + dprintk(1, "dqbuf: file io in progress\n"); + return -EBUSY; + } + + if (b->type != q->type) { + dprintk(1, "dqbuf: invalid buffer type\n"); + return -EINVAL; + } + + ret = __vb2_get_done_vb(q, &vb, nonblocking); + if (ret < 0) { + dprintk(1, "dqbuf: error getting next done buffer\n"); + return ret; + } + + ret = call_qop(q, buf_finish, vb); + if (ret) { + dprintk(1, "dqbuf: buffer finish failed\n"); + return ret; + } + + switch (vb->state) { + case VB2_BUF_STATE_DONE: + dprintk(3, "dqbuf: Returning done buffer\n"); + break; + case VB2_BUF_STATE_ERROR: + dprintk(3, "dqbuf: Returning done buffer with errors\n"); + break; + default: + dprintk(1, "dqbuf: Invalid buffer state\n"); + return -EINVAL; + } + + /* Fill buffer information for the userspace */ + __fill_v4l2_buffer(vb, b); + /* Remove from videobuf queue */ + list_del(&vb->queued_entry); + + dprintk(1, "dqbuf of buffer %d, with state %d\n", + vb->v4l2_buf.index, vb->state); + + vb->state = VB2_BUF_STATE_DEQUEUED; + return 0; +} +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) starts streaming and passes any previously queued buffers to the driver + * + * 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) +{ + struct vb2_buffer *vb; + int ret; + + if (q->fileio) { + dprintk(1, "streamon: file io in progress\n"); + return -EBUSY; + } + + if (type != q->type) { + dprintk(1, "streamon: invalid stream type\n"); + return -EINVAL; + } + + if (q->streaming) { + dprintk(1, "streamon: already streaming\n"); + return -EBUSY; + } + + /* + * Cannot start streaming on an OUTPUT device if no buffers have + * been queued yet. + */ + if (V4L2_TYPE_IS_OUTPUT(q->type)) { + if (list_empty(&q->queued_list)) { + dprintk(1, "streamon: no output buffers queued\n"); + return -EINVAL; + } + } + + /* + * Let driver notice that streaming state has been enabled. + */ + ret = call_qop(q, start_streaming, q); + if (ret) { + dprintk(1, "streamon: driver refused to start streaming\n"); + return ret; + } + + q->streaming = 1; + + /* + * If any buffers were queued before streamon, + * we can now pass them to driver for processing. + */ + list_for_each_entry(vb, &q->queued_list, queued_entry) + __enqueue_in_driver(vb); + + dprintk(3, "Streamon successful\n"); + return 0; +} +EXPORT_SYMBOL_GPL(vb2_streamon); + +/** + * __vb2_queue_cancel() - cancel and stop (pause) streaming + * + * Removes all queued buffers from driver's queue and all buffers queued by + * userspace from videobuf's queue. Returns to state after reqbufs. + */ +static void __vb2_queue_cancel(struct vb2_queue *q) +{ + unsigned int i; + + /* + * Tell driver to stop all transactions and release all queued + * buffers. + */ + if (q->streaming) + call_qop(q, stop_streaming, q); + q->streaming = 0; + + /* + * Remove all buffers from videobuf's list... + */ + INIT_LIST_HEAD(&q->queued_list); + /* + * ...and done list; userspace will not receive any buffers it + * has not already dequeued before initiating cancel. + */ + INIT_LIST_HEAD(&q->done_list); + wake_up_all(&q->done_wq); + + /* + * Reinitialize all buffers for next use. + */ + for (i = 0; i < q->num_buffers; ++i) + q->bufs[i]->state = VB2_BUF_STATE_DEQUEUED; +} + +/** + * 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 (q->fileio) { + dprintk(1, "streamoff: file io in progress\n"); + return -EBUSY; + } + + if (type != q->type) { + dprintk(1, "streamoff: invalid stream type\n"); + return -EINVAL; + } + + if (!q->streaming) { + dprintk(1, "streamoff: not streaming\n"); + return -EINVAL; + } + + /* + * Cancel will pause streaming and remove all buffers from the driver + * and videobuf, effectively returning control over them to userspace. + */ + __vb2_queue_cancel(q); + + dprintk(3, "Streamoff successful\n"); + return 0; +} +EXPORT_SYMBOL_GPL(vb2_streamoff); + +/** + * __find_plane_by_offset() - find plane associated with the given offset off + */ +static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off, + unsigned int *_buffer, unsigned int *_plane) +{ + struct vb2_buffer *vb; + unsigned int buffer, plane; + + /* + * Go over all buffers and their planes, comparing the given offset + * with an offset assigned to each plane. If a match is found, + * return its buffer and plane numbers. + */ + for (buffer = 0; buffer < q->num_buffers; ++buffer) { + vb = q->bufs[buffer]; + + for (plane = 0; plane < vb->num_planes; ++plane) { + if (vb->v4l2_planes[plane].m.mem_offset == off) { + *_buffer = buffer; + *_plane = plane; + return 0; + } + } + } + + return -EINVAL; +} + +/** + * vb2_mmap() - map video buffers into application address space + * @q: videobuf2 queue + * @vma: vma passed to the mmap file operation handler in the driver + * + * Should be called from mmap file operation handler of a driver. + * This function maps one plane of one of the available video buffers to + * userspace. To map whole video memory allocated on reqbufs, this function + * has to be called once per each plane per each buffer previously allocated. + * + * When the userspace application calls mmap, it passes to it an offset returned + * to it earlier by the means of vidioc_querybuf handler. That offset acts as + * a "cookie", which is then used to identify the plane to be mapped. + * This function finds a plane with a matching offset and a mapping is performed + * by the means of a provided memory operation. + * + * The return values from this function are intended to be directly returned + * from the mmap handler in driver. + */ +int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) +{ + unsigned long off = vma->vm_pgoff << PAGE_SHIFT; + struct vb2_plane *vb_plane; + struct vb2_buffer *vb; + unsigned int buffer, plane; + int ret; + + if (q->memory != V4L2_MEMORY_MMAP) { + dprintk(1, "Queue is not currently set up for mmap\n"); + return -EINVAL; + } + + /* + * Check memory area access mode. + */ + if (!(vma->vm_flags & VM_SHARED)) { + dprintk(1, "Invalid vma flags, VM_SHARED needed\n"); + return -EINVAL; + } + if (V4L2_TYPE_IS_OUTPUT(q->type)) { + if (!(vma->vm_flags & VM_WRITE)) { + dprintk(1, "Invalid vma flags, VM_WRITE needed\n"); + return -EINVAL; + } + } else { + if (!(vma->vm_flags & VM_READ)) { + dprintk(1, "Invalid vma flags, VM_READ needed\n"); + return -EINVAL; + } + } + + /* + * Find the plane corresponding to the offset passed by userspace. + */ + ret = __find_plane_by_offset(q, off, &buffer, &plane); + if (ret) + return ret; + + vb = q->bufs[buffer]; + vb_plane = &vb->planes[plane]; + + ret = q->mem_ops->mmap(vb_plane->mem_priv, vma); + if (ret) + return ret; + + vb_plane->mapped = 1; + vb->num_planes_mapped++; + + dprintk(3, "Buffer %d, plane %d successfully mapped\n", buffer, plane); + return 0; +} +EXPORT_SYMBOL_GPL(vb2_mmap); + +static int __vb2_init_fileio(struct vb2_queue *q, int read); +static int __vb2_cleanup_fileio(struct vb2_queue *q); + +/** + * 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. + * + * 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) +{ + unsigned long flags; + unsigned int ret; + struct vb2_buffer *vb = NULL; + + /* + * Start file I/O emulator only if streaming API has not been used yet. + */ + if (q->num_buffers == 0 && q->fileio == NULL) { + if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ)) { + ret = __vb2_init_fileio(q, 1); + if (ret) + return POLLERR; + } + if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE)) { + ret = __vb2_init_fileio(q, 0); + if (ret) + return POLLERR; + /* + * Write to OUTPUT queue can be done immediately. + */ + return POLLOUT | POLLWRNORM; + } + } + + /* + * There is nothing to wait for if no buffers have already been queued. + */ + if (list_empty(&q->queued_list)) + return POLLERR; + + poll_wait(file, &q->done_wq, wait); + + /* + * Take first buffer available for dequeuing. + */ + spin_lock_irqsave(&q->done_lock, flags); + if (!list_empty(&q->done_list)) + vb = list_first_entry(&q->done_list, struct vb2_buffer, + done_entry); + spin_unlock_irqrestore(&q->done_lock, flags); + + if (vb && (vb->state == VB2_BUF_STATE_DONE + || vb->state == VB2_BUF_STATE_ERROR)) { + return (V4L2_TYPE_IS_OUTPUT(q->type)) ? POLLOUT | POLLWRNORM : + POLLIN | POLLRDNORM; + } + return 0; +} +EXPORT_SYMBOL_GPL(vb2_poll); + +/** + * 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) +{ + BUG_ON(!q); + BUG_ON(!q->ops); + BUG_ON(!q->mem_ops); + BUG_ON(!q->type); + BUG_ON(!q->io_modes); + + BUG_ON(!q->ops->queue_setup); + BUG_ON(!q->ops->buf_queue); + + INIT_LIST_HEAD(&q->queued_list); + INIT_LIST_HEAD(&q->done_list); + spin_lock_init(&q->done_lock); + init_waitqueue_head(&q->done_wq); + + if (q->buf_struct_size == 0) + q->buf_struct_size = sizeof(struct vb2_buffer); + + return 0; +} +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_cleanup_fileio(q); + __vb2_queue_cancel(q); + __vb2_queue_free(q); +} +EXPORT_SYMBOL_GPL(vb2_queue_release); + +/** + * struct vb2_fileio_buf - buffer context used by file io emulator + * + * vb2 provides a compatibility layer and emulator of file io (read and + * write) calls on top of streaming API. This structure is used for + * tracking context related to the buffers. + */ +struct vb2_fileio_buf { + void *vaddr; + unsigned int size; + unsigned int pos; + unsigned int queued:1; +}; + +/** + * struct vb2_fileio_data - queue context used by file io emulator + * + * vb2 provides a compatibility layer and emulator of file io (read and + * write) calls on top of streaming API. For proper operation it required + * this structure to save the driver state between each call of the read + * or write function. + */ +struct vb2_fileio_data { + struct v4l2_requestbuffers req; + struct v4l2_buffer b; + struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME]; + unsigned int index; + unsigned int q_count; + unsigned int dq_count; + unsigned int flags; +}; + +/** + * __vb2_init_fileio() - initialize file io emulator + * @q: videobuf2 queue + * @read: mode selector (1 means read, 0 means write) + */ +static int __vb2_init_fileio(struct vb2_queue *q, int read) +{ + struct vb2_fileio_data *fileio; + int i, ret; + unsigned int count = 0; + + /* + * Sanity check + */ + if ((read && !(q->io_modes & VB2_READ)) || + (!read && !(q->io_modes & VB2_WRITE))) + BUG(); + + /* + * Check if device supports mapping buffers to kernel virtual space. + */ + if (!q->mem_ops->vaddr) + return -EBUSY; + + /* + * Check if streaming api has not been already activated. + */ + if (q->streaming || q->num_buffers > 0) + return -EBUSY; + + /* + * Start with count 1, driver can increase it in queue_setup() + */ + count = 1; + + dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n", + (read) ? "read" : "write", count, q->io_flags); + + fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL); + if (fileio == NULL) + return -ENOMEM; + + fileio->flags = q->io_flags; + + /* + * Request buffers and use MMAP type to force driver + * to allocate buffers by itself. + */ + fileio->req.count = count; + fileio->req.memory = V4L2_MEMORY_MMAP; + fileio->req.type = q->type; + ret = vb2_reqbufs(q, &fileio->req); + if (ret) + goto err_kfree; + + /* + * Check if plane_count is correct + * (multiplane buffers are not supported). + */ + if (q->bufs[0]->num_planes != 1) { + fileio->req.count = 0; + ret = -EBUSY; + goto err_reqbufs; + } + + /* + * Get kernel address of each buffer. + */ + for (i = 0; i < q->num_buffers; i++) { + fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0); + if (fileio->bufs[i].vaddr == NULL) + goto err_reqbufs; + fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0); + } + + /* + * Read mode requires pre queuing of all buffers. + */ + if (read) { + /* + * Queue all buffers. + */ + for (i = 0; i < q->num_buffers; i++) { + struct v4l2_buffer *b = &fileio->b; + memset(b, 0, sizeof(*b)); + b->type = q->type; + b->memory = q->memory; + b->index = i; + ret = vb2_qbuf(q, b); + if (ret) + goto err_reqbufs; + fileio->bufs[i].queued = 1; + } + + /* + * Start streaming. + */ + ret = vb2_streamon(q, q->type); + if (ret) + goto err_reqbufs; + } + + q->fileio = fileio; + + return ret; + +err_reqbufs: + vb2_reqbufs(q, &fileio->req); + +err_kfree: + kfree(fileio); + return ret; +} + +/** + * __vb2_cleanup_fileio() - free resourced used by file io emulator + * @q: videobuf2 queue + */ +static int __vb2_cleanup_fileio(struct vb2_queue *q) +{ + struct vb2_fileio_data *fileio = q->fileio; + + if (fileio) { + /* + * Hack fileio context to enable direct calls to vb2 ioctl + * interface. + */ + q->fileio = NULL; + + vb2_streamoff(q, q->type); + fileio->req.count = 0; + vb2_reqbufs(q, &fileio->req); + kfree(fileio); + dprintk(3, "file io emulator closed\n"); + } + return 0; +} + +/** + * __vb2_perform_fileio() - perform a single file io (read or write) operation + * @q: videobuf2 queue + * @data: pointed to target userspace buffer + * @count: number of bytes to read or write + * @ppos: file handle position tracking pointer + * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking) + * @read: access mode selector (1 means read, 0 means write) + */ +static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count, + loff_t *ppos, int nonblock, int read) +{ + struct vb2_fileio_data *fileio; + struct vb2_fileio_buf *buf; + int ret, index; + + dprintk(3, "file io: mode %s, offset %ld, count %zd, %sblocking\n", + read ? "read" : "write", (long)*ppos, count, + nonblock ? "non" : ""); + + if (!data) + return -EINVAL; + + /* + * Initialize emulator on first call. + */ + if (!q->fileio) { + ret = __vb2_init_fileio(q, read); + dprintk(3, "file io: vb2_init_fileio result: %d\n", ret); + if (ret) + return ret; + } + fileio = q->fileio; + + /* + * Hack fileio context to enable direct calls to vb2 ioctl interface. + * The pointer will be restored before returning from this function. + */ + q->fileio = NULL; + + index = fileio->index; + buf = &fileio->bufs[index]; + + /* + * Check if we need to dequeue the buffer. + */ + if (buf->queued) { + struct vb2_buffer *vb; + + /* + * Call vb2_dqbuf to get buffer back. + */ + memset(&fileio->b, 0, sizeof(fileio->b)); + fileio->b.type = q->type; + fileio->b.memory = q->memory; + fileio->b.index = index; + ret = vb2_dqbuf(q, &fileio->b, nonblock); + dprintk(5, "file io: vb2_dqbuf result: %d\n", ret); + if (ret) + goto end; + fileio->dq_count += 1; + + /* + * Get number of bytes filled by the driver + */ + vb = q->bufs[index]; + buf->size = vb2_get_plane_payload(vb, 0); + buf->queued = 0; + } + + /* + * Limit count on last few bytes of the buffer. + */ + if (buf->pos + count > buf->size) { + count = buf->size - buf->pos; + dprintk(5, "reducing read count: %zd\n", count); + } + + /* + * Transfer data to userspace. + */ + dprintk(3, "file io: copying %zd bytes - buffer %d, offset %u\n", + count, index, buf->pos); + if (read) + ret = copy_to_user(data, buf->vaddr + buf->pos, count); + else + ret = copy_from_user(buf->vaddr + buf->pos, data, count); + if (ret) { + dprintk(3, "file io: error copying data\n"); + ret = -EFAULT; + goto end; + } + + /* + * Update counters. + */ + buf->pos += count; + *ppos += count; + + /* + * Queue next buffer if required. + */ + if (buf->pos == buf->size || + (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATELY))) { + /* + * Check if this is the last buffer to read. + */ + if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) && + fileio->dq_count == 1) { + dprintk(3, "file io: read limit reached\n"); + /* + * Restore fileio pointer and release the context. + */ + q->fileio = fileio; + return __vb2_cleanup_fileio(q); + } + + /* + * Call vb2_qbuf and give buffer to the driver. + */ + memset(&fileio->b, 0, sizeof(fileio->b)); + fileio->b.type = q->type; + fileio->b.memory = q->memory; + fileio->b.index = index; + fileio->b.bytesused = buf->pos; + ret = vb2_qbuf(q, &fileio->b); + dprintk(5, "file io: vb2_dbuf result: %d\n", ret); + if (ret) + goto end; + + /* + * Buffer has been queued, update the status + */ + buf->pos = 0; + buf->queued = 1; + buf->size = q->bufs[0]->v4l2_planes[0].length; + fileio->q_count += 1; + + /* + * Switch to the next buffer + */ + fileio->index = (index + 1) % q->num_buffers; + + /* + * Start streaming if required. + */ + if (!read && !q->streaming) { + ret = vb2_streamon(q, q->type); + if (ret) + goto end; + } + } + + /* + * Return proper number of bytes processed. + */ + if (ret == 0) + ret = count; +end: + /* + * Restore the fileio context and block vb2 ioctl interface. + */ + q->fileio = fileio; + return ret; +} + +size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, + loff_t *ppos, int nonblocking) +{ + return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1); +} +EXPORT_SYMBOL_GPL(vb2_read); + +size_t vb2_write(struct vb2_queue *q, char __user *data, size_t count, + loff_t *ppos, int nonblocking) +{ + return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 0); +} +EXPORT_SYMBOL_GPL(vb2_write); + +MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2"); +MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski"); +MODULE_LICENSE("GPL"); |
