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Diffstat (limited to 'include/media/demux.h')
| -rw-r--r-- | include/media/demux.h | 589 |
1 files changed, 589 insertions, 0 deletions
diff --git a/include/media/demux.h b/include/media/demux.h new file mode 100644 index 000000000000..c4df6cee48e6 --- /dev/null +++ b/include/media/demux.h @@ -0,0 +1,589 @@ +/* + * 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: 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; /* Back-pointer */ + void *priv; /* Pointer to private data of the API client */ +}; + +/** + * 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. + * + * 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); + +/** + * 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. + * + * 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); + +/* + * 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 */ |