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 /*
  * 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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