@@ -503,6 +503,11 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
unsigned int num_buffers, num_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");
@@ -846,6 +851,10 @@ 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");
@@ -1019,6 +1028,10 @@ 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");
@@ -1083,6 +1096,10 @@ int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
struct vb2_buffer *vb;
int ret = 0;
+ if (q->fileio) {
+ dprintk(1, "streamon: file io in progress\n");
+ return -EBUSY;
+ }
if (type != q->type) {
dprintk(1, "streamon: invalid stream type\n");
@@ -1174,6 +1191,10 @@ int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
{
int ret = 0;
+ if (q->fileio) {
+ dprintk(1, "streamoff: file io in progress\n");
+ return -EBUSY;
+ }
if (type != q->type) {
dprintk(1, "streamoff: invalid stream type\n");
@@ -1312,6 +1333,9 @@ bool vb2_has_consumers(struct vb2_queue *q)
}
EXPORT_SYMBOL_GPL(vb2_has_consumers);
+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
@@ -1334,6 +1358,22 @@ unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
unsigned int ret = 0;
struct vb2_buffer *vb = NULL;
+ /*
+ * Start file io emulator if streaming api has not been used yet.
+ */
+ if (q->num_buffers == 0 && q->fileio == NULL) {
+ if (!V4L2_TYPE_IS_OUTPUT(q->type) && q->ops->read_setup) {
+ ret = __vb2_init_fileio(q, 1);
+ if (ret)
+ goto end;
+ }
+ if (V4L2_TYPE_IS_OUTPUT(q->type) && q->ops->write_setup) {
+ ret = __vb2_init_fileio(q, 1);
+ if (ret == 0)
+ ret = POLLOUT | POLLWRNORM;
+ goto end;
+ }
+ }
/*
* There is nothing to wait for if no buffers have already been queued.
@@ -1424,11 +1464,366 @@ EXPORT_SYMBOL_GPL(vb2_queue_init);
*/
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, flags=0;
+
+ /*
+ * Sanity check
+ */
+ if ((read && !q->ops->read_setup) || (!read && !q->ops->write_setup))
+ 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 file io emulator
+ */
+ if (read)
+ ret = call_qop(q, read_setup, q, &count, &flags);
+ else
+ ret = call_qop(q, write_setup, q, &count, &flags);
+ if (ret)
+ return ret;
+
+ dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
+ (read) ? "read" : "write", count, flags);
+
+ fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
+ if (fileio == NULL)
+ return -ENOMEM;
+
+ fileio->flags = 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() - free resourced used by read() emulator
+ * @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 %d, %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: %d\n", count);
+ }
+
+ /*
+ * Transfer data to userspace.
+ */
+ dprintk(3, "file io: copying %d bytes - buffer %d, offset %d\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_IMMEDIATE))) {
+ /*
+ * 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");
+MODULE_AUTHOR("Pawel Osciak, Marek Szyprowski");
MODULE_LICENSE("GPL");
@@ -18,6 +18,7 @@
#include <linux/poll.h>
struct vb2_alloc_ctx;
+struct vb2_fileio_data;
/**
* struct vb2_mem_ops - memory handling/memory allocator operations
@@ -95,6 +96,17 @@ struct vb2_plane {
};
/**
+ * enum vb2_fileio_flags - flags for selecting a mode of the file io emulator,
+ * by default the 'streaming' style is used by the file io emulator
+ * @VB2_FILEIO_READ_ONCE: report EOF after reading the first buffer
+ * @VB2_FILEIO_WRITE_IMMEDIATE: queue buffer after each write() call
+ */
+enum vb2_fileio_flags {
+ VB2_FILEIO_READ_ONCE = (1<<0),
+ VB2_FILEIO_WRITE_IMMEDIATE = (1<<1),
+};
+
+/**
* enum vb2_buffer_state - current video buffer state
* @VB2_BUF_STATE_DEQUEUED: buffer under userspace control
* @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver
@@ -169,6 +181,12 @@ struct vb2_buffer {
* @plane_setup: called before memory allocation num_planes times;
* driver should return the required size of plane number
* plane_no
+ * @read_setup: called before enabling read() style io; asks the driver
+ * for the number of buffers and flags used by the
+ * emulator; see vb2_fileio_flags for more information
+ * @write_setup: called before enabling write() style io; asks the driver
+ * for the number of buffers and flags used by the
+ * emulator; see vb2_fileio_flags for more information
* @lock: aquire all locks taken before any other calls to vb2;
* required after sleeing in poll_wait function
* @unlock: release any locks taken before calling vb2 function;
@@ -211,6 +229,11 @@ struct vb2_ops {
int (*plane_setup)(struct vb2_queue *q,
unsigned int plane_no, unsigned long *plane_size);
+ int (*read_setup)(struct vb2_queue *q,
+ unsigned int *count, unsigned int *flags);
+ int (*write_setup)(struct vb2_queue *q,
+ unsigned int *count, unsigned int *flags);
+
void (*lock)(struct vb2_queue *q);
void (*unlock)(struct vb2_queue *q);
@@ -245,6 +268,7 @@ struct vb2_ops {
* @streaming: current streaming state
* @userptr_supported: true if queue supports USERPTR types
* @mmap_supported: true if queue supports MMAP types
+ * @fileio: file io emulator internal data, used only if emulator is active
*/
struct vb2_queue {
enum v4l2_buf_type type;
@@ -267,6 +291,8 @@ struct vb2_queue {
int streaming:1;
int userptr_supported:1;
int mmap_supported:1;
+
+ struct vb2_fileio_data *fileio;
};
void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
@@ -291,6 +317,10 @@ 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 nonblock);
+size_t vb2_write(struct vb2_queue *q, char __user *data, size_t count,
+ loff_t *ppos, int nonblock);
/**
* vb2_is_streaming() - return streaming status of the queue