@@ -471,7 +471,7 @@ static bool __buffers_in_use(struct vb2_queue *q)
* 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)
+static int __vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
{
unsigned int num_buffers, num_planes;
int ret = 0;
@@ -482,8 +482,6 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
return -EINVAL;
}
- mutex_lock(&q->vb_lock);
-
if (req->type != q->type) {
dprintk(1, "reqbufs: queue type invalid\n");
ret = -EINVAL;
@@ -567,6 +565,15 @@ end:
mutex_unlock(&q->vb_lock);
return ret;
}
+
+int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
+{
+ int ret = 0;
+ mutex_lock(&q->vb_lock);
+ ret = (q->read_data) ? -EBUSY : __vb2_reqbufs(q, req);
+ mutex_unlock(&q->vb_lock);
+ return ret;
+}
EXPORT_SYMBOL_GPL(vb2_reqbufs);
/**
@@ -821,14 +828,11 @@ static void __enqueue_in_driver(struct vb2_buffer *vb)
* 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)
+static int __vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
{
struct vb2_buffer *vb;
- int ret;
-
- mutex_lock(&q->vb_lock);
+ int ret = -EINVAL;
- ret = -EINVAL;
if (b->type != q->type) {
dprintk(1, "qbuf: invalid buffer type\n");
goto done;
@@ -887,6 +891,14 @@ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
ret = 0;
done:
+ return ret;
+}
+
+int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
+{
+ int ret = 0;
+ mutex_lock(&q->vb_lock);
+ ret = (q->read_data) ? -EBUSY : __vb2_qbuf(q, b);
mutex_unlock(&q->vb_lock);
return ret;
}
@@ -996,13 +1008,11 @@ end:
* 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)
+static int __vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
{
struct vb2_buffer *vb = NULL;
int ret;
- mutex_lock(&q->vb_lock);
-
if (b->type != q->type) {
dprintk(1, "dqbuf: invalid buffer type\n");
ret = -EINVAL;
@@ -1047,6 +1057,14 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
vb->state = VB2_BUF_STATE_DEQUEUED;
done:
+ return ret;
+}
+
+int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
+{
+ int ret;
+ mutex_lock(&q->vb_lock);
+ ret = (q->read_data) ? -EBUSY : __vb2_dqbuf(q, b, nonblocking);
mutex_unlock(&q->vb_lock);
return ret;
}
@@ -1065,13 +1083,11 @@ EXPORT_SYMBOL_GPL(vb2_dqbuf);
* 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)
+static int __vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
{
struct vb2_buffer *vb;
int ret = 0;
- mutex_lock(&q->vb_lock);
-
if (type != q->type) {
dprintk(1, "streamon: invalid stream type\n");
ret = -EINVAL;
@@ -1113,6 +1129,14 @@ int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
dprintk(3, "Streamon successful\n");
done:
+ return ret;
+}
+
+int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
+{
+ int ret;
+ mutex_lock(&q->vb_lock);
+ ret = (q->read_data) ? -EBUSY : __vb2_streamon(q, type);
mutex_unlock(&q->vb_lock);
return ret;
}
@@ -1161,12 +1185,10 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
* 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)
+static int __vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
{
int ret = 0;
- mutex_lock(&q->vb_lock);
-
if (type != q->type) {
dprintk(1, "streamoff: invalid stream type\n");
ret = -EINVAL;
@@ -1187,6 +1209,14 @@ int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
dprintk(3, "Streamoff successful\n");
end:
+ return ret;
+}
+
+int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
+{
+ int ret;
+ mutex_lock(&q->vb_lock);
+ ret = (q->read_data) ? -EBUSY : __vb2_streamoff(q, type);
mutex_unlock(&q->vb_lock);
return ret;
}
@@ -1311,6 +1341,9 @@ bool vb2_has_consumers(struct vb2_queue *q)
}
EXPORT_SYMBOL_GPL(vb2_has_consumers);
+static int __vb2_init_read(struct vb2_queue *q);
+static int __vb2_cleanup_read(struct vb2_queue *q);
+
/**
* vb2_poll() - implements poll userspace operation
* @q: videobuf2 queue
@@ -1336,6 +1369,15 @@ unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
mutex_lock(&q->vb_lock);
/*
+ * Start read() emulator if streaming api has not been used yet.
+ */
+ if (q->num_buffers == 0 && q->read_data == NULL && q->read_ctx) {
+ ret = __vb2_init_read(q);
+ if (ret)
+ goto end;
+ }
+
+ /*
* There is nothing to wait for if no buffers have already been queued.
*/
if (list_empty(&q->queued_list)) {
@@ -1378,12 +1420,15 @@ EXPORT_SYMBOL_GPL(vb2_poll);
* the given context will be used for memory allocation on all
* planes and buffers; it is possible to assign different contexts
* per plane, use vb2_set_alloc_ctx() for that
+ * @read_ctx: parameters for read() api to be used; can be NULL if no read
+ * callback is used
* @type: queue type
* @drv_priv: driver private data, may be NULL; it can be used by driver in
* driver-specific callbacks when issued
*/
int vb2_queue_init(struct vb2_queue *q, const struct vb2_ops *ops,
const struct vb2_alloc_ctx *alloc_ctx,
+ const struct vb2_read_ctx *read_ctx,
enum v4l2_buf_type type, void *drv_priv)
{
unsigned int i;
@@ -1403,6 +1448,7 @@ int vb2_queue_init(struct vb2_queue *q, const struct vb2_ops *ops,
for (i = 0; i < VIDEO_MAX_PLANES; ++i)
q->alloc_ctx[i] = alloc_ctx;
+ q->read_ctx = read_ctx;
q->type = type;
q->drv_priv = drv_priv;
@@ -1428,6 +1474,7 @@ void vb2_queue_release(struct vb2_queue *q)
{
mutex_lock(&q->vb_lock);
+ __vb2_cleanup_read(q);
__vb2_queue_cancel(q);
__vb2_queue_free(q);
@@ -1435,6 +1482,245 @@ void vb2_queue_release(struct vb2_queue *q)
}
EXPORT_SYMBOL_GPL(vb2_queue_release);
+/**
+ * struct vb2_read_data - internal structure used by read() emulator
+ *
+ * vb2 provides a compatibility layer and emulator of read() calls on top
+ * of streaming api. For proper operation it required this structure to
+ * save the driver state between each call of the read function.
+ */
+struct vb2_read_data {
+ struct v4l2_requestbuffers req;
+ struct v4l2_buffer b;
+ void *buff_vaddr[VIDEO_MAX_FRAME];
+ unsigned cur_offset;
+ unsigned cur_bufsize;
+ unsigned read_offset;
+ int cur_buffer;
+ int buffer_count;
+};
+
+/**
+ * __vb2_init_read() - initialize read() emulator
+ * @q: videobuf2 queue
+ */
+static int __vb2_init_read(struct vb2_queue *q)
+{
+ struct vb2_read_data *rd;
+ int i, ret;
+
+ if (!q->read_ctx)
+ BUG();
+
+ /*
+ * Check if device supports mapping buffers to kernel virtual space
+ */
+ if (!q->alloc_ctx[0]->mem_ops->vaddr)
+ return -EBUSY;
+
+ /*
+ * Check if steaming api has not been already activated.
+ */
+ if (q->streaming || q->num_buffers > 0)
+ return -EBUSY;
+
+ /*
+ * Basic checks done, lets try to set up read emulator
+ */
+ dprintk(3, "setting up read() emulator\n");
+
+ q->read_data = kmalloc(sizeof(struct vb2_read_data), GFP_KERNEL);
+ if (q->read_data == NULL)
+ return -ENOMEM;
+
+ memset(q->read_data, 0, sizeof(*q->read_data));
+ rd = q->read_data;
+
+ /*
+ * Request buffers and use MMAP type to force driver
+ * to allocate buffers by itself.
+ */
+ rd->req.count = q->read_ctx->num_bufs;
+ rd->req.memory = V4L2_MEMORY_MMAP;
+ rd->req.type = q->type;
+ ret = __vb2_reqbufs(q, &rd->req);
+ if (ret)
+ goto err_kfree;
+
+ /*
+ * Check if plane_count is correct
+ * (multiplane buffers are not supported).
+ */
+ if (q->bufs[0]->num_planes != 1) {
+ rd->req.count = 0;
+ ret = -EBUSY;
+ goto err_reqbufs;
+ }
+
+ /*
+ * Get kernel address of each buffer.
+ */
+ for (i = 0; i < q->num_buffers; i++)
+ rd->buff_vaddr[i] = vb2_plane_vaddr(q->bufs[i], 0);
+
+ /*
+ * Queue all buffers.
+ */
+ for (i = 0; i < q->num_buffers; i++) {
+ memset(&rd->b, 0, sizeof(rd->b));
+ rd->b.type = q->type;
+ rd->b.memory = q->memory;
+ rd->b.index = i;
+ ret = __vb2_qbuf(q, &rd->b);
+ if (ret)
+ goto err_reqbufs;
+ }
+
+ /*
+ * Start streaming.
+ */
+ ret = __vb2_streamon(q, q->type);
+ if (ret)
+ goto err_reqbufs;
+
+ return ret;
+
+err_reqbufs:
+ __vb2_reqbufs(q, &rd->req);
+
+err_kfree:
+ kfree(q->read_data);
+ return ret;
+}
+
+/**
+ * __vb2_cleanup_read() - free resourced used by read() emulator
+ * @q: videobuf2 queue
+ */
+static int __vb2_cleanup_read(struct vb2_queue *q)
+{
+ struct vb2_read_data *rd = q->read_data;
+ if (rd) {
+ __vb2_streamoff(q, q->type);
+ rd->req.count = 0;
+ __vb2_reqbufs(q, &rd->req);
+ kfree(rd);
+ q->read_data = NULL;
+ dprintk(3, "read() emulator released\n");
+ }
+ return 0;
+}
+
+size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
+ loff_t *ppos, int nonblocking)
+{
+ struct vb2_read_data *rd;
+ int ret;
+
+ dprintk(3, "read: offset %ld, count %d, %sblocking\n", (long)*ppos,
+ count, nonblocking ? "non" : "");
+
+ if (!data)
+ return -EINVAL;
+
+ mutex_lock(&q->vb_lock);
+
+ /*
+ * Initialize emulator on first read() call.
+ */
+ if (!q->read_data) {
+ ret = __vb2_init_read(q);
+ dprintk(3, "read: vb2_init_read result: %d\n", ret);
+ if (ret)
+ goto end;
+ }
+
+ rd = q->read_data;
+
+ /*
+ * Current buffer is empty...
+ */
+ if (rd->cur_offset == 0 && rd->cur_bufsize == 0) {
+ /*
+ * ... check if this was the last buffer to read.
+ */
+ if (q->read_ctx->read_once &&
+ rd->buffer_count == q->read_ctx->num_bufs) {
+ ret = __vb2_cleanup_read(q);
+ goto end;
+ }
+
+ /*
+ * ... or call vb2_dqbuf to get next buffer with data.
+ */
+ memset(&rd->b, 0, sizeof(rd->b));
+ rd->b.type = q->type;
+ rd->b.memory = q->memory;
+ rd->b.index = rd->cur_buffer;
+ ret = __vb2_dqbuf(q, &rd->b, nonblocking);
+ dprintk(5, "read: vb2_dqbuf result: %d\n", ret);
+ if (ret)
+ goto end;
+ rd->buffer_count += 1;
+ rd->cur_bufsize = rd->b.length;
+ }
+
+ /*
+ * Limit count on last few bytes of the buffer.
+ */
+ if (count + rd->cur_offset > rd->cur_bufsize) {
+ count = rd->cur_bufsize - rd->cur_offset;
+ dprintk(5, "reducing read count: %d\n", count);
+ }
+
+ /*
+ * Transfer data to userspace.
+ */
+ dprintk(3, "read: copying %d data from buffer %d (offset %d bytes)\n",
+ count, rd->cur_buffer, rd->cur_offset);
+ if (copy_to_user(data,
+ rd->buff_vaddr[rd->cur_buffer] + rd->cur_offset,
+ count)) {
+ dprintk(3, "read: error copying data\n");
+ ret = -EFAULT;
+ goto end;
+ }
+
+ /*
+ * Update counters.
+ */
+ rd->cur_offset += count;
+ rd->read_offset += count;
+ *ppos += count;
+
+ /*
+ * Queue next buffer if required.
+ */
+ if (rd->cur_offset == rd->cur_bufsize) {
+ memset(&rd->b, 0, sizeof(rd->b));
+ rd->b.type = q->type;
+ rd->b.memory = q->memory;
+ rd->b.index = rd->cur_buffer;
+ ret = __vb2_qbuf(q, &rd->b);
+ dprintk(5, "read: vb2_dbuf result: %d\n", ret);
+ if (ret)
+ goto end;
+ rd->cur_buffer = (rd->cur_buffer + 1) % q->num_buffers;
+ rd->cur_offset = 0;
+ rd->cur_bufsize = 0;
+ }
+
+ /*
+ * Return proper number of bytes read.
+ */
+ if (ret == 0)
+ ret = count;
+end:
+ mutex_unlock(&q->vb_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(vb2_read);
+
MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
-MODULE_AUTHOR("Pawel Osciak");
+MODULE_AUTHOR("Pawel Osciak, Marek Szyprowski");
MODULE_LICENSE("GPL");
@@ -18,6 +18,7 @@
#include <linux/poll.h>
struct vb2_alloc_ctx;
+struct vb2_read_data;
/**
* struct vb2_mem_ops - memory handling/memory allocator operations
@@ -210,6 +211,18 @@ struct vb2_ops {
};
/**
+ * struct vb2_read_ctx - defaults for read() callback emulator
+ *
+ * @num_bufs: number of buffers used by the emulator
+ * @read_once: determines weather read emulator return EOF after processing
+ * @num_bufs or queues buffer again for new data
+ */
+struct vb2_read_ctx {
+ int num_bufs;
+ int read_once;
+};
+
+/**
* struct vb2_queue - a videobuf queue
*
* @type: current queue type
@@ -227,6 +240,8 @@ struct vb2_ops {
* @streaming: current streaming state
* @userptr_supported: true if queue supports USERPTR types
* @mmap_supported: true if queue supports MMAP types
+ * @read_ctx: defaults for read() emulator, can be NULL
+ * @read_data: read() emulator internal data, used only if emulator is active
*/
struct vb2_queue {
enum v4l2_buf_type type;
@@ -250,6 +265,9 @@ struct vb2_queue {
int streaming:1;
int userptr_supported:1;
int mmap_supported:1;
+
+ const struct vb2_read_ctx *read_ctx;
+ struct vb2_read_data *read_data;
};
void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
@@ -262,6 +280,7 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req);
int vb2_queue_init(struct vb2_queue *q, const struct vb2_ops *ops,
const struct vb2_alloc_ctx *alloc_ctx,
+ const struct vb2_read_ctx *read_ctx,
enum v4l2_buf_type type, void *drv_priv);
void vb2_queue_release(struct vb2_queue *q);
@@ -273,6 +292,8 @@ int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type);
int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait);
+size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
+ loff_t *ppos, int nonblocking);
/**
* vb2_is_streaming() - return streaming status of the queue