Release 4.16 include/media/demux.h
/*
* demux.h
*
* The Kernel Digital TV Demux kABI defines a driver-internal interface for
* registering low-level, hardware specific driver to a hardware independent
* demux layer.
*
* Copyright (c) 2002 Convergence GmbH
*
* based on code:
* Copyright (c) 2000 Nokia Research Center
* Tampere, FINLAND
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#ifndef __DEMUX_H
#define __DEMUX_H
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/time.h>
#include <linux/dvb/dmx.h>
/*
* Common definitions
*/
/*
* DMX_MAX_FILTER_SIZE: Maximum length (in bytes) of a section/PES filter.
*/
#ifndef DMX_MAX_FILTER_SIZE
#define DMX_MAX_FILTER_SIZE 18
#endif
/*
* DMX_MAX_SECFEED_SIZE: Maximum length (in bytes) of a private section feed
* filter.
*/
#ifndef DMX_MAX_SECTION_SIZE
#define DMX_MAX_SECTION_SIZE 4096
#endif
#ifndef DMX_MAX_SECFEED_SIZE
#define DMX_MAX_SECFEED_SIZE (DMX_MAX_SECTION_SIZE + 188)
#endif
/*
* TS packet reception
*/
/**
* enum ts_filter_type - filter type bitmap for dmx_ts_feed.set\(\)
*
* @TS_PACKET: Send TS packets (188 bytes) to callback (default).
* @TS_PAYLOAD_ONLY: In case TS_PACKET is set, only send the TS payload
* (<=184 bytes per packet) to callback
* @TS_DECODER: Send stream to built-in decoder (if present).
* @TS_DEMUX: In case TS_PACKET is set, send the TS to the demux
* device, not to the dvr device
*/
enum ts_filter_type {
TS_PACKET = 1,
TS_PAYLOAD_ONLY = 2,
TS_DECODER = 4,
TS_DEMUX = 8,
};
/**
* struct dmx_ts_feed - Structure that contains a TS feed filter
*
* @is_filtering: Set to non-zero when filtering in progress
* @parent: pointer to struct dmx_demux
* @priv: pointer to private data of the API client
* @set: sets the TS filter
* @start_filtering: starts TS filtering
* @stop_filtering: stops TS filtering
*
* A TS feed is typically mapped to a hardware PID filter on the demux chip.
* Using this API, the client can set the filtering properties to start/stop
* filtering TS packets on a particular TS feed.
*/
struct dmx_ts_feed {
int is_filtering;
struct dmx_demux *parent;
void *priv;
int (*set)(struct dmx_ts_feed *feed,
u16 pid,
int type,
enum dmx_ts_pes pes_type,
ktime_t timeout);
int (*start_filtering)(struct dmx_ts_feed *feed);
int (*stop_filtering)(struct dmx_ts_feed *feed);
};
/*
* Section reception
*/
/**
* struct dmx_section_filter - Structure that describes a section filter
*
* @filter_value: Contains up to 16 bytes (128 bits) of the TS section header
* that will be matched by the section filter
* @filter_mask: Contains a 16 bytes (128 bits) filter mask with the bits
* specified by @filter_value that will be used on the filter
* match logic.
* @filter_mode: Contains a 16 bytes (128 bits) filter mode.
* @parent: Back-pointer to struct dmx_section_feed.
* @priv: Pointer to private data of the API client.
*
*
* The @filter_mask controls which bits of @filter_value are compared with
* the section headers/payload. On a binary value of 1 in filter_mask, the
* corresponding bits are compared. The filter only accepts sections that are
* equal to filter_value in all the tested bit positions.
*/
struct dmx_section_filter {
u8 filter_value[DMX_MAX_FILTER_SIZE];
u8 filter_mask[DMX_MAX_FILTER_SIZE];
u8 filter_mode[DMX_MAX_FILTER_SIZE];
struct dmx_section_feed *parent;
void *priv;
};
/**
* struct dmx_section_feed - Structure that contains a section feed filter
*
* @is_filtering: Set to non-zero when filtering in progress
* @parent: pointer to struct dmx_demux
* @priv: pointer to private data of the API client
* @check_crc: If non-zero, check the CRC values of filtered sections.
* @set: sets the section filter
* @allocate_filter: This function is used to allocate a section filter on
* the demux. It should only be called when no filtering
* is in progress on this section feed. If a filter cannot
* be allocated, the function fails with -ENOSPC.
* @release_filter: This function releases all the resources of a
* previously allocated section filter. The function
* should not be called while filtering is in progress
* on this section feed. After calling this function,
* the caller should not try to dereference the filter
* pointer.
* @start_filtering: starts section filtering
* @stop_filtering: stops section filtering
*
* A TS feed is typically mapped to a hardware PID filter on the demux chip.
* Using this API, the client can set the filtering properties to start/stop
* filtering TS packets on a particular TS feed.
*/
struct dmx_section_feed {
int is_filtering;
struct dmx_demux *parent;
void *priv;
int check_crc;
/* private: Used internally at dvb_demux.c */
u32 crc_val;
u8 *secbuf;
u8 secbuf_base[DMX_MAX_SECFEED_SIZE];
u16 secbufp, seclen, tsfeedp;
/* public: */
int (*set)(struct dmx_section_feed *feed,
u16 pid,
int check_crc);
int (*allocate_filter)(struct dmx_section_feed *feed,
struct dmx_section_filter **filter);
int (*release_filter)(struct dmx_section_feed *feed,
struct dmx_section_filter *filter);
int (*start_filtering)(struct dmx_section_feed *feed);
int (*stop_filtering)(struct dmx_section_feed *feed);
};
/**
* typedef dmx_ts_cb - DVB demux TS filter callback function prototype
*
* @buffer1: Pointer to the start of the filtered TS packets.
* @buffer1_length: Length of the TS data in buffer1.
* @buffer2: Pointer to the tail of the filtered TS packets, or NULL.
* @buffer2_length: Length of the TS data in buffer2.
* @source: Indicates which TS feed is the source of the callback.
* @buffer_flags: Address where buffer flags are stored. Those are
* used to report discontinuity users via DVB
* memory mapped API, as defined by
* &enum dmx_buffer_flags.
*
* This function callback prototype, provided by the client of the demux API,
* is called from the demux code. The function is only called when filtering
* on a TS feed has been enabled using the start_filtering\(\) function at
* the &dmx_demux.
* Any TS packets that match the filter settings are copied to a circular
* buffer. The filtered TS packets are delivered to the client using this
* callback function.
* It is expected that the @buffer1 and @buffer2 callback parameters point to
* addresses within the circular buffer, but other implementations are also
* possible. Note that the called party should not try to free the memory
* the @buffer1 and @buffer2 parameters point to.
*
* When this function is called, the @buffer1 parameter typically points to
* the start of the first undelivered TS packet within a circular buffer.
* The @buffer2 buffer parameter is normally NULL, except when the received
* TS packets have crossed the last address of the circular buffer and
* "wrapped" to the beginning of the buffer. In the latter case the @buffer1
* parameter would contain an address within the circular buffer, while the
* @buffer2 parameter would contain the first address of the circular buffer.
* The number of bytes delivered with this function (i.e. @buffer1_length +
* @buffer2_length) is usually equal to the value of callback_length parameter
* given in the set() function, with one exception: if a timeout occurs before
* receiving callback_length bytes of TS data, any undelivered packets are
* immediately delivered to the client by calling this function. The timeout
* duration is controlled by the set() function in the TS Feed API.
*
* If a TS packet is received with errors that could not be fixed by the
* TS-level forward error correction (FEC), the Transport_error_indicator
* flag of the TS packet header should be set. The TS packet should not be
* discarded, as the error can possibly be corrected by a higher layer
* protocol. If the called party is slow in processing the callback, it
* is possible that the circular buffer eventually fills up. If this happens,
* the demux driver should discard any TS packets received while the buffer
* is full and return -EOVERFLOW.
*
* The type of data returned to the callback can be selected by the
* &dmx_ts_feed.@set function. The type parameter decides if the raw
* TS packet (TS_PACKET) or just the payload (TS_PACKET|TS_PAYLOAD_ONLY)
* should be returned. If additionally the TS_DECODER bit is set the stream
* will also be sent to the hardware MPEG decoder.
*
* Return:
*
* - 0, on success;
*
* - -EOVERFLOW, on buffer overflow.
*/
typedef int (*dmx_ts_cb)(const u8 *buffer1,
size_t buffer1_length,
const u8 *buffer2,
size_t buffer2_length,
struct dmx_ts_feed *source,
u32 *buffer_flags);
/**
* typedef dmx_section_cb - DVB demux TS filter callback function prototype
*
* @buffer1: Pointer to the start of the filtered section, e.g.
* within the circular buffer of the demux driver.
* @buffer1_len: Length of the filtered section data in @buffer1,
* including headers and CRC.
* @buffer2: Pointer to the tail of the filtered section data,
* or NULL. Useful to handle the wrapping of a
* circular buffer.
* @buffer2_len: Length of the filtered section data in @buffer2,
* including headers and CRC.
* @source: Indicates which section feed is the source of the
* callback.
* @buffer_flags: Address where buffer flags are stored. Those are
* used to report discontinuity users via DVB
* memory mapped API, as defined by
* &enum dmx_buffer_flags.
*
* This function callback prototype, provided by the client of the demux API,
* is called from the demux code. The function is only called when
* filtering of sections has been enabled using the function
* &dmx_ts_feed.@start_filtering. When the demux driver has received a
* complete section that matches at least one section filter, the client
* is notified via this callback function. Normally this function is called
* for each received section; however, it is also possible to deliver
* multiple sections with one callback, for example when the system load
* is high. If an error occurs while receiving a section, this
* function should be called with the corresponding error type set in the
* success field, whether or not there is data to deliver. The Section Feed
* implementation should maintain a circular buffer for received sections.
* However, this is not necessary if the Section Feed API is implemented as
* a client of the TS Feed API, because the TS Feed implementation then
* buffers the received data. The size of the circular buffer can be
* configured using the &dmx_ts_feed.@set function in the Section Feed API.
* If there is no room in the circular buffer when a new section is received,
* the section must be discarded. If this happens, the value of the success
* parameter should be DMX_OVERRUN_ERROR on the next callback.
*/
typedef int (*dmx_section_cb)(const u8 *buffer1,
size_t buffer1_len,
const u8 *buffer2,
size_t buffer2_len,
struct dmx_section_filter *source,
u32 *buffer_flags);
/*
* DVB Front-End
*/
/**
* enum dmx_frontend_source - Used to identify the type of frontend
*
* @DMX_MEMORY_FE: The source of the demux is memory. It means that
* the MPEG-TS to be filtered comes from userspace,
* via write() syscall.
*
* @DMX_FRONTEND_0: The source of the demux is a frontend connected
* to the demux.
*/
enum dmx_frontend_source {
DMX_MEMORY_FE,
DMX_FRONTEND_0,
};
/**
* struct dmx_frontend - Structure that lists the frontends associated with
* a demux
*
* @connectivity_list: List of front-ends that can be connected to a
* particular demux;
* @source: Type of the frontend.
*
* FIXME: this structure should likely be replaced soon by some
* media-controller based logic.
*/
struct dmx_frontend {
struct list_head connectivity_list;
enum dmx_frontend_source source;
};
/*
* MPEG-2 TS Demux
*/
/**
* enum dmx_demux_caps - MPEG-2 TS Demux capabilities bitmap
*
* @DMX_TS_FILTERING: set if TS filtering is supported;
* @DMX_SECTION_FILTERING: set if section filtering is supported;
* @DMX_MEMORY_BASED_FILTERING: set if write() available.
*
* Those flags are OR'ed in the &dmx_demux.capabilities field
*/
enum dmx_demux_caps {
DMX_TS_FILTERING = 1,
DMX_SECTION_FILTERING = 4,
DMX_MEMORY_BASED_FILTERING = 8,
};
/*
* Demux resource type identifier.
*/
/**
* DMX_FE_ENTRY - Casts elements in the list of registered
* front-ends from the generic type struct list_head
* to the type * struct dmx_frontend
*
* @list: list of struct dmx_frontend
*/
#define DMX_FE_ENTRY(list) \
list_entry(list, struct dmx_frontend, connectivity_list)
/**
* struct dmx_demux - Structure that contains the demux capabilities and
* callbacks.
*
* @capabilities: Bitfield of capability flags.
*
* @frontend: Front-end connected to the demux
*
* @priv: Pointer to private data of the API client
*
* @open: This function reserves the demux for use by the caller and, if
* necessary, initializes the demux. When the demux is no longer needed,
* the function @close should be called. It should be possible for
* multiple clients to access the demux at the same time. Thus, the
* function implementation should increment the demux usage count when
* @open is called and decrement it when @close is called.
* The @demux function parameter contains a pointer to the demux API and
* instance data.
* It returns:
* 0 on success;
* -EUSERS, if maximum usage count was reached;
* -EINVAL, on bad parameter.
*
* @close: This function reserves the demux for use by the caller and, if
* necessary, initializes the demux. When the demux is no longer needed,
* the function @close should be called. It should be possible for
* multiple clients to access the demux at the same time. Thus, the
* function implementation should increment the demux usage count when
* @open is called and decrement it when @close is called.
* The @demux function parameter contains a pointer to the demux API and
* instance data.
* It returns:
* 0 on success;
* -ENODEV, if demux was not in use (e. g. no users);
* -EINVAL, on bad parameter.
*
* @write: This function provides the demux driver with a memory buffer
* containing TS packets. Instead of receiving TS packets from the DVB
* front-end, the demux driver software will read packets from memory.
* Any clients of this demux with active TS, PES or Section filters will
* receive filtered data via the Demux callback API (see 0). The function
* returns when all the data in the buffer has been consumed by the demux.
* Demux hardware typically cannot read TS from memory. If this is the
* case, memory-based filtering has to be implemented entirely in software.
* The @demux function parameter contains a pointer to the demux API and
* instance data.
* The @buf function parameter contains a pointer to the TS data in
* kernel-space memory.
* The @count function parameter contains the length of the TS data.
* It returns:
* 0 on success;
* -ERESTARTSYS, if mutex lock was interrupted;
* -EINTR, if a signal handling is pending;
* -ENODEV, if demux was removed;
* -EINVAL, on bad parameter.
*
* @allocate_ts_feed: Allocates a new TS feed, which is used to filter the TS
* packets carrying a certain PID. The TS feed normally corresponds to a
* hardware PID filter on the demux chip.
* The @demux function parameter contains a pointer to the demux API and
* instance data.
* The @feed function parameter contains a pointer to the TS feed API and
* instance data.
* The @callback function parameter contains a pointer to the callback
* function for passing received TS packet.
* It returns:
* 0 on success;
* -ERESTARTSYS, if mutex lock was interrupted;
* -EBUSY, if no more TS feeds is available;
* -EINVAL, on bad parameter.
*
* @release_ts_feed: Releases the resources allocated with @allocate_ts_feed.
* Any filtering in progress on the TS feed should be stopped before
* calling this function.
* The @demux function parameter contains a pointer to the demux API and
* instance data.
* The @feed function parameter contains a pointer to the TS feed API and
* instance data.
* It returns:
* 0 on success;
* -EINVAL on bad parameter.
*
* @allocate_section_feed: Allocates a new section feed, i.e. a demux resource
* for filtering and receiving sections. On platforms with hardware
* support for section filtering, a section feed is directly mapped to
* the demux HW. On other platforms, TS packets are first PID filtered in
* hardware and a hardware section filter then emulated in software. The
* caller obtains an API pointer of type dmx_section_feed_t as an out
* parameter. Using this API the caller can set filtering parameters and
* start receiving sections.
* The @demux function parameter contains a pointer to the demux API and
* instance data.
* The @feed function parameter contains a pointer to the TS feed API and
* instance data.
* The @callback function parameter contains a pointer to the callback
* function for passing received TS packet.
* It returns:
* 0 on success;
* -EBUSY, if no more TS feeds is available;
* -EINVAL, on bad parameter.
*
* @release_section_feed: Releases the resources allocated with
* @allocate_section_feed, including allocated filters. Any filtering in
* progress on the section feed should be stopped before calling this
* function.
* The @demux function parameter contains a pointer to the demux API and
* instance data.
* The @feed function parameter contains a pointer to the TS feed API and
* instance data.
* It returns:
* 0 on success;
* -EINVAL, on bad parameter.
*
* @add_frontend: Registers a connectivity between a demux and a front-end,
* i.e., indicates that the demux can be connected via a call to
* @connect_frontend to use the given front-end as a TS source. The
* client of this function has to allocate dynamic or static memory for
* the frontend structure and initialize its fields before calling this
* function. This function is normally called during the driver
* initialization. The caller must not free the memory of the frontend
* struct before successfully calling @remove_frontend.
* The @demux function parameter contains a pointer to the demux API and
* instance data.
* The @frontend function parameter contains a pointer to the front-end
* instance data.
* It returns:
* 0 on success;
* -EINVAL, on bad parameter.
*
* @remove_frontend: Indicates that the given front-end, registered by a call
* to @add_frontend, can no longer be connected as a TS source by this
* demux. The function should be called when a front-end driver or a demux
* driver is removed from the system. If the front-end is in use, the
* function fails with the return value of -EBUSY. After successfully
* calling this function, the caller can free the memory of the frontend
* struct if it was dynamically allocated before the @add_frontend
* operation.
* The @demux function parameter contains a pointer to the demux API and
* instance data.
* The @frontend function parameter contains a pointer to the front-end
* instance data.
* It returns:
* 0 on success;
* -ENODEV, if the front-end was not found,
* -EINVAL, on bad parameter.
*
* @get_frontends: Provides the APIs of the front-ends that have been
* registered for this demux. Any of the front-ends obtained with this
* call can be used as a parameter for @connect_frontend. The include
* file demux.h contains the macro DMX_FE_ENTRY() for converting an
* element of the generic type struct &list_head * to the type
* struct &dmx_frontend *. The caller must not free the memory of any of
* the elements obtained via this function call.
* The @demux function parameter contains a pointer to the demux API and
* instance data.
* It returns a struct list_head pointer to the list of front-end
* interfaces, or NULL in the case of an empty list.
*
* @connect_frontend: Connects the TS output of the front-end to the input of
* the demux. A demux can only be connected to a front-end registered to
* the demux with the function @add_frontend. It may or may not be
* possible to connect multiple demuxes to the same front-end, depending
* on the capabilities of the HW platform. When not used, the front-end
* should be released by calling @disconnect_frontend.
* The @demux function parameter contains a pointer to the demux API and
* instance data.
* The @frontend function parameter contains a pointer to the front-end
* instance data.
* It returns:
* 0 on success;
* -EINVAL, on bad parameter.
*
* @disconnect_frontend: Disconnects the demux and a front-end previously
* connected by a @connect_frontend call.
* The @demux function parameter contains a pointer to the demux API and
* instance data.
* It returns:
* 0 on success;
* -EINVAL on bad parameter.
*
* @get_pes_pids: Get the PIDs for DMX_PES_AUDIO0, DMX_PES_VIDEO0,
* DMX_PES_TELETEXT0, DMX_PES_SUBTITLE0 and DMX_PES_PCR0.
* The @demux function parameter contains a pointer to the demux API and
* instance data.
* The @pids function parameter contains an array with five u16 elements
* where the PIDs will be stored.
* It returns:
* 0 on success;
* -EINVAL on bad parameter.
*/
struct dmx_demux {
enum dmx_demux_caps capabilities;
struct dmx_frontend *frontend;
void *priv;
int (*open)(struct dmx_demux *demux);
int (*close)(struct dmx_demux *demux);
int (*write)(struct dmx_demux *demux, const char __user *buf,
size_t count);
int (*allocate_ts_feed)(struct dmx_demux *demux,
struct dmx_ts_feed **feed,
dmx_ts_cb callback);
int (*release_ts_feed)(struct dmx_demux *demux,
struct dmx_ts_feed *feed);
int (*allocate_section_feed)(struct dmx_demux *demux,
struct dmx_section_feed **feed,
dmx_section_cb callback);
int (*release_section_feed)(struct dmx_demux *demux,
struct dmx_section_feed *feed);
int (*add_frontend)(struct dmx_demux *demux,
struct dmx_frontend *frontend);
int (*remove_frontend)(struct dmx_demux *demux,
struct dmx_frontend *frontend);
struct list_head *(*get_frontends)(struct dmx_demux *demux);
int (*connect_frontend)(struct dmx_demux *demux,
struct dmx_frontend *frontend);
int (*disconnect_frontend)(struct dmx_demux *demux);
int (*get_pes_pids)(struct dmx_demux *demux, u16 *pids);
/* private: */
/*
* Only used at av7110, to read some data from firmware.
* As this was never documented, we have no clue about what's
* there, and its usage on other drivers aren't encouraged.
*/
int (*get_stc)(struct dmx_demux *demux, unsigned int num,
u64 *stc, unsigned int *base);
};
#endif /* #ifndef __DEMUX_H */
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