/*
* SPDX-License-Identifier: GPL-2.0
*
* dvb-vb2.h - DVB driver helper framework for streaming I/O
*
* Copyright (C) 2015 Samsung Electronics
*
* Author: [email protected]
*
* 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.
*/
#ifndef _DVB_VB2_H
#define _DVB_VB2_H
#include <linux/mutex.h>
#include <linux/poll.h>
#include <linux/dvb/dmx.h>
#include <media/videobuf2-core.h>
#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,
};
/**
* 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.
* @flags: buffer flags as defined by &enum dmx_buffer_flags.
* Filled only at &DMX_DQBUF. &DMX_QBUF should zero this field.
* @count: monotonic counter for filled buffers. Helps to identify
* data stream loses. Filled only at &DMX_DQBUF. &DMX_QBUF should
* zero this field.
*
* @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;
spinlock_t slock;
struct list_head dvb_q;
struct dvb_buffer *buf;
int offset;
int remain;
int state;
int buf_siz;
int buf_cnt;
int nonblocking;
enum dmx_buffer_flags flags;
u32 count;
char name[DVB_VB2_NAME_MAX + 1];
};
#ifndef CONFIG_DVB_MMAP
static inline int dvb_vb2_init(struct dvb_vb2_ctx *ctx,
const char *name, int non_blocking)
{
return 0;
};
static inline int dvb_vb2_release(struct dvb_vb2_ctx *ctx)
{
return 0;
};
#define dvb_vb2_is_streaming(ctx) (0)
#define dvb_vb2_fill_buffer(ctx, file, wait, flags) (0)
static inline __poll_t dvb_vb2_poll(struct dvb_vb2_ctx *ctx,
struct file *file,
poll_table *wait)
{
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
* @buffer_flags:
* pointer to buffer flags as defined by &enum dmx_buffer_flags.
* can be NULL.
*/
int dvb_vb2_fill_buffer(struct dvb_vb2_ctx *ctx,
const unsigned char *src, int len,
enum dmx_buffer_flags *buffer_flags);
/**
* 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.
*/
__poll_t 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 */
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