/* * 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 … #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 … #endif #ifndef DMX_MAX_SECFEED_SIZE #define DMX_MAX_SECFEED_SIZE … #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 { … }; /** * 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 { … }; /* * 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 { … }; /** * 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 { … }; /** * 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. */ dmx_ts_cb; /** * 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. */ dmx_section_cb; /* * 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 { … }; /** * 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 { … }; /* * 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 { … }; /* * 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) … /** * 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 { … }; #endif /* #ifndef __DEMUX_H */
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