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authorMauro Carvalho Chehab <mchehab@s-opensource.com>2017-12-29 08:23:41 -0500
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2017-12-29 08:31:25 -0500
commit9f577d6db5bf7d76fb9e26894a92fcb4ecb4c832 (patch)
treeee9d3cf62534e68c34a01a568aceff517a14d6aa /include/media
parent15128beef1ce3d48565f44756ff4a2077ac97a01 (diff)
downloadlinux-9f577d6db5bf7d76fb9e26894a92fcb4ecb4c832.tar.bz2
media: dvb kAPI docs: document dvb_vb2.h
Document the data structures and functions inside this kAPI header. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'include/media')
-rw-r--r--include/media/dmxdev.h2
-rw-r--r--include/media/dvb_vb2.h183
2 files changed, 179 insertions, 6 deletions
diff --git a/include/media/dmxdev.h b/include/media/dmxdev.h
index d5bef0da2e6e..2f5cb2c7b6a7 100644
--- a/include/media/dmxdev.h
+++ b/include/media/dmxdev.h
@@ -112,6 +112,7 @@ struct dmxdev_feed {
* @state: state of the dmxdev filter, as defined by &enum dmxdev_state.
* @dev: pointer to &struct dmxdev.
* @buffer: an embedded &struct dvb_ringbuffer buffer.
+ * @vb2_ctx: control struct for VB2 handler
* @mutex: protects the access to &struct dmxdev_filter.
* @timer: &struct timer_list embedded timer, used to check for
* feed timeouts.
@@ -165,6 +166,7 @@ struct dmxdev_filter {
* @exit: flag to indicate that the demux is being released.
* @dvr_orig_fe: pointer to &struct dmx_frontend.
* @dvr_buffer: embedded &struct dvb_ringbuffer for DVB output.
+ * @dvr_vb2_ctx: control struct for VB2 handler
* @mutex: protects the usage of this structure.
* @lock: protects access to &dmxdev->filter->data.
*/
diff --git a/include/media/dvb_vb2.h b/include/media/dvb_vb2.h
index ef4a802f7435..5431e5a7e140 100644
--- a/include/media/dvb_vb2.h
+++ b/include/media/dvb_vb2.h
@@ -22,22 +22,72 @@
#include <media/videobuf2-dma-contig.h>
#include <media/videobuf2-vmalloc.h>
+/**
+ * enum dvb_buf_type - types of Digital TV memory-mapped buffers
+ *
+ * @DVB_BUF_TYPE_CAPTURE: buffer is filled by the Kernel,
+ * with a received Digital TV stream
+ */
enum dvb_buf_type {
DVB_BUF_TYPE_CAPTURE = 1,
};
-#define DVB_VB2_STATE_NONE (0x0)
-#define DVB_VB2_STATE_INIT (0x1)
-#define DVB_VB2_STATE_REQBUFS (0x2)
-#define DVB_VB2_STATE_STREAMON (0x4)
+/**
+ * enum dvb_vb2_states - states to control VB2 state machine
+ * @DVB_VB2_STATE_NONE:
+ * VB2 engine not initialized yet, init failed or VB2 was released.
+ * @DVB_VB2_STATE_INIT:
+ * VB2 engine initialized.
+ * @DVB_VB2_STATE_REQBUFS:
+ * Buffers were requested
+ * @DVB_VB2_STATE_STREAMON:
+ * VB2 is streaming. Callers should not check it directly. Instead,
+ * they should use dvb_vb2_is_streaming().
+ *
+ * Note:
+ *
+ * Callers should not touch at the state machine directly. This
+ * is handled inside dvb_vb2.c.
+ */
+enum dvb_vb2_states {
+ DVB_VB2_STATE_NONE = 0x0,
+ DVB_VB2_STATE_INIT = 0x1,
+ DVB_VB2_STATE_REQBUFS = 0x2,
+ DVB_VB2_STATE_STREAMON = 0x4,
+};
#define DVB_VB2_NAME_MAX (20)
+/**
+ * struct dvb_buffer - video buffer information for v4l2.
+ *
+ * @vb: embedded struct &vb2_buffer.
+ * @list: list of &struct dvb_buffer.
+ */
struct dvb_buffer {
struct vb2_buffer vb;
struct list_head list;
};
+/**
+ * struct dvb_vb2_ctx - control struct for VB2 handler
+ * @vb_q: pointer to &struct vb2_queue with videobuf2 queue.
+ * @mutex: mutex to serialize vb2 operations. Used by
+ * vb2 core %wait_prepare and %wait_finish operations.
+ * @slock: spin lock used to protect buffer filling at dvb_vb2.c.
+ * @dvb_q: List of buffers that are not filled yet.
+ * @buf: Pointer to the buffer that are currently being filled.
+ * @offset: index to the next position at the @buf to be filled.
+ * @remain: How many bytes are left to be filled at @buf.
+ * @state: bitmask of buffer states as defined by &enum dvb_vb2_states.
+ * @buf_siz: size of each VB2 buffer.
+ * @buf_cnt: number of VB2 buffers.
+ * @nonblocking:
+ * If different than zero, device is operating on non-blocking
+ * mode.
+ * @name: name of the device type. Currently, it can either be
+ * "dvr" or "demux_filter".
+ */
struct dvb_vb2_ctx {
struct vb2_queue vb_q;
struct mutex mutex;
@@ -53,8 +103,6 @@ struct dvb_vb2_ctx {
char name[DVB_VB2_NAME_MAX + 1];
};
-int dvb_vb2_stream_on(struct dvb_vb2_ctx *ctx);
-int dvb_vb2_stream_off(struct dvb_vb2_ctx *ctx);
#ifndef DVB_MMAP
static inline int dvb_vb2_init(struct dvb_vb2_ctx *ctx,
const char *name, int non_blocking)
@@ -75,21 +123,144 @@ static inline unsigned int dvb_vb2_poll(struct dvb_vb2_ctx *ctx,
return 0;
}
#else
+/**
+ * dvb_vb2_init - initializes VB2 handler
+ *
+ * @ctx: control struct for VB2 handler
+ * @name: name for the VB2 handler
+ * @non_blocking:
+ * if not zero, it means that the device is at non-blocking mode
+ */
int dvb_vb2_init(struct dvb_vb2_ctx *ctx, const char *name, int non_blocking);
+
+/**
+ * dvb_vb2_release - Releases the VB2 handler allocated resources and
+ * put @ctx at DVB_VB2_STATE_NONE state.
+ * @ctx: control struct for VB2 handler
+ */
int dvb_vb2_release(struct dvb_vb2_ctx *ctx);
+
+/**
+ * dvb_vb2_is_streaming - checks if the VB2 handler is streaming
+ * @ctx: control struct for VB2 handler
+ *
+ * Return: 0 if not streaming, 1 otherwise.
+ */
int dvb_vb2_is_streaming(struct dvb_vb2_ctx *ctx);
+
+/**
+ * dvb_vb2_fill_buffer - fills a VB2 buffer
+ * @ctx: control struct for VB2 handler
+ * @src: place where the data is stored
+ * @len: number of bytes to be copied from @src
+ */
int dvb_vb2_fill_buffer(struct dvb_vb2_ctx *ctx,
const unsigned char *src, int len);
+
+/**
+ * dvb_vb2_poll - Wrapper to vb2_core_streamon() for Digital TV
+ * buffer handling.
+ *
+ * @ctx: control struct for VB2 handler
+ * @file: &struct file argument passed to the poll
+ * file operation handler.
+ * @wait: &poll_table wait argument passed to the poll
+ * file operation handler.
+ *
+ * Implements poll syscall() logic.
+ */
unsigned int dvb_vb2_poll(struct dvb_vb2_ctx *ctx, struct file *file,
poll_table *wait);
#endif
+/**
+ * dvb_vb2_stream_on() - Wrapper to vb2_core_streamon() for Digital TV
+ * buffer handling.
+ *
+ * @ctx: control struct for VB2 handler
+ *
+ * Starts dvb streaming
+ */
+int dvb_vb2_stream_on(struct dvb_vb2_ctx *ctx);
+/**
+ * dvb_vb2_stream_off() - Wrapper to vb2_core_streamoff() for Digital TV
+ * buffer handling.
+ *
+ * @ctx: control struct for VB2 handler
+ *
+ * Stops dvb streaming
+ */
+int dvb_vb2_stream_off(struct dvb_vb2_ctx *ctx);
+/**
+ * dvb_vb2_reqbufs() - Wrapper to vb2_core_reqbufs() for Digital TV
+ * buffer handling.
+ *
+ * @ctx: control struct for VB2 handler
+ * @req: &struct dmx_requestbuffers passed from userspace in
+ * order to handle &DMX_REQBUFS.
+ *
+ * Initiate streaming by requesting a number of buffers. Also used to
+ * free previously requested buffers, is ``req->count`` is zero.
+ */
int dvb_vb2_reqbufs(struct dvb_vb2_ctx *ctx, struct dmx_requestbuffers *req);
+
+/**
+ * dvb_vb2_querybuf() - Wrapper to vb2_core_querybuf() for Digital TV
+ * buffer handling.
+ *
+ * @ctx: control struct for VB2 handler
+ * @b: &struct dmx_buffer passed from userspace in
+ * order to handle &DMX_QUERYBUF.
+ *
+ *
+ */
int dvb_vb2_querybuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b);
+
+/**
+ * dvb_vb2_expbuf() - Wrapper to vb2_core_expbuf() for Digital TV
+ * buffer handling.
+ *
+ * @ctx: control struct for VB2 handler
+ * @exp: &struct dmx_exportbuffer passed from userspace in
+ * order to handle &DMX_EXPBUF.
+ *
+ * Export a buffer as a file descriptor.
+ */
int dvb_vb2_expbuf(struct dvb_vb2_ctx *ctx, struct dmx_exportbuffer *exp);
+
+/**
+ * dvb_vb2_qbuf() - Wrapper to vb2_core_qbuf() for Digital TV buffer handling.
+ *
+ * @ctx: control struct for VB2 handler
+ * @b: &struct dmx_buffer passed from userspace in
+ * order to handle &DMX_QBUF.
+ *
+ * Queue a Digital TV buffer as requested by userspace
+ */
int dvb_vb2_qbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b);
+
+/**
+ * dvb_vb2_dqbuf() - Wrapper to vb2_core_dqbuf() for Digital TV
+ * buffer handling.
+ *
+ * @ctx: control struct for VB2 handler
+ * @b: &struct dmx_buffer passed from userspace in
+ * order to handle &DMX_DQBUF.
+ *
+ * Dequeue a Digital TV buffer to the userspace
+ */
int dvb_vb2_dqbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b);
+
+/**
+ * dvb_vb2_mmap() - Wrapper to vb2_mmap() for Digital TV buffer handling.
+ *
+ * @ctx: control struct for VB2 handler
+ * @vma: pointer to &struct vm_area_struct with the vma passed
+ * to the mmap file operation handler in the driver.
+ *
+ * map Digital TV video buffers into application address space.
+ */
int dvb_vb2_mmap(struct dvb_vb2_ctx *ctx, struct vm_area_struct *vma);
#endif /* _DVB_VB2_H */