Skip to content

L
linux
Commit 95abfdb9 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files
Options

[media] DocBook: Move struct dmx_demux kABI doc to demux.h 

The DocBook/media/dvb/kdapi.xml contains the description of
the kABI for DVB. The problem is that, by being maintained
on a separate file and not being updated for years, it got
outdated. So, for example, some callback parameters were
changed, but the DocBook were still using the old stuff.

As a first step to fix it, let's move the documentation of
struct dmx_demux into demux.h and fix the parameters used
there.

For now, don't document any other field nor touch the
descriptions that got moved, letting this job to other
patches. That makes easier to review the patch.

PS.: Please notice that an additional patch will be needed
in order to fix the return values (some uses non-existent
return codes) and to the functions and callbacks mentioned at
the descriptions.
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent bdbbf13e
Hide whitespace changes
Inline Side-by-side
Showing with 191 additions and 1037 deletions
Documentation/DocBook/device-drivers.tmpl
View file @ 95abfdb9
......@@ -239,6 +239,7 @@ X!Isound/sound_firmware.c
</sect1>
<sect1><title>Digital TV (DVB) devices</title>
!Idrivers/media/dvb-core/dvb_ca_en50221.h
!Idrivers/media/dvb-core/demux.h
!Idrivers/media/dvb-core/dvb_frontend.h
!Idrivers/media/dvb-core/dvb_math.h
!Idrivers/media/dvb-core/dvb_ringbuffer.h
......
Documentation/DocBook/media/dvb/kdapi.xml
View file @ 95abfdb9
......@@ -214,62 +214,6 @@ should be kept identical) to the types in the demux device.
&#x22C6; to the type &#x22C6; dmx_frontend_t
&#x22C6;.
&#x22C6;/
#define DMX_FE_ENTRY(list) list_entry(list, dmx_frontend_t, connectivity_list)
struct dmx_demux_s {
/&#x22C6; The following char&#x22C6; fields point to NULL terminated strings &#x22C6;/
char&#x22C6; id; /&#x22C6; Unique demux identifier &#x22C6;/
char&#x22C6; vendor; /&#x22C6; Name of the demux vendor &#x22C6;/
char&#x22C6; model; /&#x22C6; Name of the demux model &#x22C6;/
__u32 capabilities; /&#x22C6; Bitfield of capability flags &#x22C6;/
dmx_frontend_t&#x22C6; frontend; /&#x22C6; Front-end connected to the demux &#x22C6;/
struct list_head reg_list; /&#x22C6; List of registered demuxes &#x22C6;/
void&#x22C6; priv; /&#x22C6; Pointer to private data of the API client &#x22C6;/
int users; /&#x22C6; Number of users &#x22C6;/
int (&#x22C6;open) (struct dmx_demux_s&#x22C6; demux);
int (&#x22C6;close) (struct dmx_demux_s&#x22C6; demux);
int (&#x22C6;write) (struct dmx_demux_s&#x22C6; demux, const char&#x22C6; buf, size_t count);
int (&#x22C6;allocate_ts_feed) (struct dmx_demux_s&#x22C6; demux,
dmx_ts_feed_t&#x22C6;&#x22C6; feed,
dmx_ts_cb callback);
int (&#x22C6;release_ts_feed) (struct dmx_demux_s&#x22C6; demux,
dmx_ts_feed_t&#x22C6; feed);
int (&#x22C6;allocate_pes_feed) (struct dmx_demux_s&#x22C6; demux,
dmx_pes_feed_t&#x22C6;&#x22C6; feed,
dmx_pes_cb callback);
int (&#x22C6;release_pes_feed) (struct dmx_demux_s&#x22C6; demux,
dmx_pes_feed_t&#x22C6; feed);
int (&#x22C6;allocate_section_feed) (struct dmx_demux_s&#x22C6; demux,
dmx_section_feed_t&#x22C6;&#x22C6; feed,
dmx_section_cb callback);
int (&#x22C6;release_section_feed) (struct dmx_demux_s&#x22C6; demux,
dmx_section_feed_t&#x22C6; feed);
int (&#x22C6;descramble_mac_address) (struct dmx_demux_s&#x22C6; demux,
__u8&#x22C6; buffer1,
size_t buffer1_length,
__u8&#x22C6; buffer2,
size_t buffer2_length,
__u16 pid);
int (&#x22C6;descramble_section_payload) (struct dmx_demux_s&#x22C6; demux,
__u8&#x22C6; buffer1,
size_t buffer1_length,
__u8&#x22C6; buffer2, size_t buffer2_length,
__u16 pid);
int (&#x22C6;add_frontend) (struct dmx_demux_s&#x22C6; demux,
dmx_frontend_t&#x22C6; frontend);
int (&#x22C6;remove_frontend) (struct dmx_demux_s&#x22C6; demux,
dmx_frontend_t&#x22C6; frontend);
struct list_head&#x22C6; (&#x22C6;get_frontends) (struct dmx_demux_s&#x22C6; demux);
int (&#x22C6;connect_frontend) (struct dmx_demux_s&#x22C6; demux,
dmx_frontend_t&#x22C6; frontend);
int (&#x22C6;disconnect_frontend) (struct dmx_demux_s&#x22C6; demux);
/&#x22C6; added because js cannot keep track of these himself &#x22C6;/
int (&#x22C6;get_pes_pids) (struct dmx_demux_s&#x22C6; demux, __u16 &#x22C6;pids);
};
typedef struct dmx_demux_s dmx_demux_t;
</programlisting>
</section>
......@@ -487,985 +431,7 @@ interface from a bottom half context. Thus, if a demux API function is called fr
device code, the function must not sleep.
</para>
<section id="kdapi_fopen">
<title>open()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>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.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int open ( demux_t&#x22C6; demux );</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>demux_t* demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>0</para>
</entry><entry
align="char">
<para>The function was completed without errors.</para>
</entry>
</row><row><entry
align="char">
<para>-EUSERS</para>
</entry><entry
align="char">
<para>Maximum usage count reached.</para>
</entry>
</row><row><entry
align="char">
<para>-EINVAL</para>
</entry><entry
align="char">
<para>Bad parameter.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section>
<section id="kdapi_fclose">
<title>close()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>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.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int close(demux_t&#x22C6; demux);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>demux_t* demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>0</para>
</entry><entry
align="char">
<para>The function was completed without errors.</para>
</entry>
</row><row><entry
align="char">
<para>-ENODEV</para>
</entry><entry
align="char">
<para>The demux was not in use.</para>
</entry>
</row><row><entry
align="char">
<para>-EINVAL</para>
</entry><entry
align="char">
<para>Bad parameter.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section>
<section id="kdapi_fwrite">
<title>write()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>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.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int write(demux_t&#x22C6; demux, const char&#x22C6; buf, size_t
count);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>demux_t* demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row><row><entry
align="char">
<para>const char* buf</para>
</entry><entry
align="char">
<para>Pointer to the TS data in kernel-space memory.</para>
</entry>
</row><row><entry
align="char">
<para>size_t length</para>
</entry><entry
align="char">
<para>Length of the TS data.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>0</para>
</entry><entry
align="char">
<para>The function was completed without errors.</para>
</entry>
</row><row><entry
align="char">
<para>-ENOSYS</para>
</entry><entry
align="char">
<para>The command is not implemented.</para>
</entry>
</row><row><entry
align="char">
<para>-EINVAL</para>
</entry><entry
align="char">
<para>Bad parameter.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>allocate_ts_feed()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>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.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int allocate_ts_feed(dmx_demux_t&#x22C6; demux,
dmx_ts_feed_t&#x22C6;&#x22C6; feed, dmx_ts_cb callback);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>demux_t* demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row><row><entry
align="char">
<para>dmx_ts_feed_t**
feed</para>
</entry><entry
align="char">
<para>Pointer to the TS feed API and instance data.</para>
</entry>
</row><row><entry
align="char">
<para>dmx_ts_cb callback</para>
</entry><entry
align="char">
<para>Pointer to the callback function for passing received TS
packet</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>0</para>
</entry><entry
align="char">
<para>The function was completed without errors.</para>
</entry>
</row><row><entry
align="char">
<para>-EBUSY</para>
</entry><entry
align="char">
<para>No more TS feeds available.</para>
</entry>
</row><row><entry
align="char">
<para>-ENOSYS</para>
</entry><entry
align="char">
<para>The command is not implemented.</para>
</entry>
</row><row><entry
align="char">
<para>-EINVAL</para>
</entry><entry
align="char">
<para>Bad parameter.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>release_ts_feed()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>Releases the resources allocated with allocate_ts_feed(). Any filtering in
progress on the TS feed should be stopped before calling this function.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int release_ts_feed(dmx_demux_t&#x22C6; demux,
dmx_ts_feed_t&#x22C6; feed);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>demux_t* demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row><row><entry
align="char">
<para>dmx_ts_feed_t* feed</para>
</entry><entry
align="char">
<para>Pointer to the TS feed API and instance data.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>0</para>
</entry><entry
align="char">
<para>The function was completed without errors.</para>
</entry>
</row><row><entry
align="char">
<para>-EINVAL</para>
</entry><entry
align="char">
<para>Bad parameter.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>allocate_section_feed()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>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.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int allocate_section_feed(dmx_demux_t&#x22C6; demux,
dmx_section_feed_t &#x22C6;&#x22C6;feed, dmx_section_cb callback);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>demux_t *demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row><row><entry
align="char">
<para>dmx_section_feed_t
**feed</para>
</entry><entry
align="char">
<para>Pointer to the section feed API and instance data.</para>
</entry>
</row><row><entry
align="char">
<para>dmx_section_cb
callback</para>
</entry><entry
align="char">
<para>Pointer to the callback function for passing received
sections.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>0</para>
</entry><entry
align="char">
<para>The function was completed without errors.</para>
</entry>
</row><row><entry
align="char">
<para>-EBUSY</para>
</entry><entry
align="char">
<para>No more section feeds available.</para>
</entry>
</row><row><entry
align="char">
<para>-ENOSYS</para>
</entry><entry
align="char">
<para>The command is not implemented.</para>
</entry>
</row><row><entry
align="char">
<para>-EINVAL</para>
</entry><entry
align="char">
<para>Bad parameter.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>release_section_feed()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>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.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int release_section_feed(dmx_demux_t&#x22C6; demux,
dmx_section_feed_t &#x22C6;feed);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>demux_t *demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row><row><entry
align="char">
<para>dmx_section_feed_t
*feed</para>
</entry><entry
align="char">
<para>Pointer to the section feed API and instance data.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>0</para>
</entry><entry
align="char">
<para>The function was completed without errors.</para>
</entry>
</row><row><entry
align="char">
<para>-EINVAL</para>
</entry><entry
align="char">
<para>Bad parameter.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>descramble_mac_address()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>This function runs a descrambling algorithm on the destination MAC
address field of a DVB Datagram Section, replacing the original address
with its un-encrypted version. Otherwise, the description on the function
descramble_section_payload() applies also to this function.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int descramble_mac_address(dmx_demux_t&#x22C6; demux, __u8
&#x22C6;buffer1, size_t buffer1_length, __u8 &#x22C6;buffer2,
size_t buffer2_length, __u16 pid);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>dmx_demux_t
*demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row><row><entry
align="char">
<para>__u8 *buffer1</para>
</entry><entry
align="char">
<para>Pointer to the first byte of the section.</para>
</entry>
</row><row><entry
align="char">
<para>size_t buffer1_length</para>
</entry><entry
align="char">
<para>Length of the section data, including headers and CRC,
in buffer1.</para>
</entry>
</row><row><entry
align="char">
<para>__u8* buffer2</para>
</entry><entry
align="char">
<para>Pointer to the tail of the section data, or NULL. The
pointer has a non-NULL value if the section wraps past
the end of a circular buffer.</para>
</entry>
</row><row><entry
align="char">
<para>size_t buffer2_length</para>
</entry><entry
align="char">
<para>Length of the section data, including headers and CRC,
in buffer2.</para>
</entry>
</row><row><entry
align="char">
<para>__u16 pid</para>
</entry><entry
align="char">
<para>The PID on which the section was received. Useful
for obtaining the descrambling key, e.g. from a DVB
Common Access facility.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>0</para>
</entry><entry
align="char">
<para>The function was completed without errors.</para>
</entry>
</row><row><entry
align="char">
<para>-ENOSYS</para>
</entry><entry
align="char">
<para>No descrambling facility available.</para>
</entry>
</row><row><entry
align="char">
<para>-EINVAL</para>
</entry><entry
align="char">
<para>Bad parameter.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>descramble_section_payload()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>This function runs a descrambling algorithm on the payload of a DVB
Datagram Section, replacing the original payload with its un-encrypted
version. The function will be called from the demux API implementation;
the API client need not call this function directly. Section-level scrambling
algorithms are currently standardized only for DVB-RCC (return channel
over 2-directional cable TV network) systems. For all other DVB networks,
encryption schemes are likely to be proprietary to each data broadcaster. Thus,
it is expected that this function pointer will have the value of NULL (i.e.,
function not available) in most demux API implementations. Nevertheless, it
should be possible to use the function pointer as a hook for dynamically adding
a &#8220;plug-in&#8221; descrambling facility to a demux driver.</para>
</entry>
</row><row><entry
align="char">
<para>While this function is not needed with hardware-based section descrambling,
the descramble_section_payload function pointer can be used to override the
default hardware-based descrambling algorithm: if the function pointer has a
non-NULL value, the corresponding function should be used instead of any
descrambling hardware.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int descramble_section_payload(dmx_demux_t&#x22C6; demux,
__u8 &#x22C6;buffer1, size_t buffer1_length, __u8 &#x22C6;buffer2,
size_t buffer2_length, __u16 pid);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>dmx_demux_t
*demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row><row><entry
align="char">
<para>__u8 *buffer1</para>
</entry><entry
align="char">
<para>Pointer to the first byte of the section.</para>
</entry>
</row><row><entry
align="char">
<para>size_t buffer1_length</para>
</entry><entry
align="char">
<para>Length of the section data, including headers and CRC,
in buffer1.</para>
</entry>
</row><row><entry
align="char">
<para>__u8 *buffer2</para>
</entry><entry
align="char">
<para>Pointer to the tail of the section data, or NULL. The
pointer has a non-NULL value if the section wraps past
the end of a circular buffer.</para>
</entry>
</row><row><entry
align="char">
<para>size_t buffer2_length</para>
</entry><entry
align="char">
<para>Length of the section data, including headers and CRC,
in buffer2.</para>
</entry>
</row><row><entry
align="char">
<para>__u16 pid</para>
</entry><entry
align="char">
<para>The PID on which the section was received. Useful
for obtaining the descrambling key, e.g. from a DVB
Common Access facility.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>0</para>
</entry><entry
align="char">
<para>The function was completed without errors.</para>
</entry>
</row><row><entry
align="char">
<para>-ENOSYS</para>
</entry><entry
align="char">
<para>No descrambling facility available.</para>
</entry>
</row><row><entry
align="char">
<para>-EINVAL</para>
</entry><entry
align="char">
<para>Bad parameter.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>add_frontend()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>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().</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int add_frontend(dmx_demux_t &#x22C6;demux, dmx_frontend_t
&#x22C6;frontend);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>dmx_demux_t*
demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row><row><entry
align="char">
<para>dmx_frontend_t*
frontend</para>
</entry><entry
align="char">
<para>Pointer to the front-end instance data.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>0</para>
</entry><entry
align="char">
<para>The function was completed without errors.</para>
</entry>
</row><row><entry
align="char">
<para>-EEXIST</para>
</entry><entry
align="char">
<para>A front-end with the same value of the id field already
registered.</para>
</entry>
</row><row><entry
align="char">
<para>-EINUSE</para>
</entry><entry
align="char">
<para>The demux is in use.</para>
</entry>
</row><row><entry
align="char">
<para>-ENOMEM</para>
</entry><entry
align="char">
<para>No more front-ends can be added.</para>
</entry>
</row><row><entry
align="char">
<para>-EINVAL</para>
</entry><entry
align="char">
<para>Bad parameter.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>remove_frontend()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>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.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int remove_frontend(dmx_demux_t&#x22C6; demux,
dmx_frontend_t&#x22C6; frontend);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>dmx_demux_t*
demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row><row><entry
align="char">
<para>dmx_frontend_t*
frontend</para>
</entry><entry
align="char">
<para>Pointer to the front-end instance data.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>0</para>
</entry><entry
align="char">
<para>The function was completed without errors.</para>
</entry>
</row><row><entry
align="char">
<para>-EINVAL</para>
</entry><entry
align="char">
<para>Bad parameter.</para>
</entry>
</row><row><entry
align="char">
<para>-EBUSY</para>
</entry><entry
align="char">
<para>The front-end is in use, i.e. a call to connect_frontend()
has not been followed by a call to disconnect_frontend().</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>get_frontends()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>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().</para>
</entry>
</row><row><entry
align="char">
<para>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
dmx_frontend_t*. The caller must not free the memory of any of the elements
obtained via this function call.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>struct list_head&#x22C6; get_frontends(dmx_demux_t&#x22C6; demux);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>dmx_demux_t*
demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>dmx_demux_t*</para>
</entry><entry
align="char">
<para>A list of front-end interfaces, or NULL in the case of an
empty list.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>connect_frontend()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>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().</para>
</entry>
</row><row><entry
align="char">
<para>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().</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int connect_frontend(dmx_demux_t&#x22C6; demux,
dmx_frontend_t&#x22C6; frontend);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>dmx_demux_t*
demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row><row><entry
align="char">
<para>dmx_frontend_t*
frontend</para>
</entry><entry
align="char">
<para>Pointer to the front-end instance data.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>0</para>
</entry><entry
align="char">
<para>The function was completed without errors.</para>
</entry>
</row><row><entry
align="char">
<para>-EINVAL</para>
</entry><entry
align="char">
<para>Bad parameter.</para>
</entry>
</row><row><entry
align="char">
<para>-EBUSY</para>
</entry><entry
align="char">
<para>The front-end is in use.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>disconnect_frontend()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>Disconnects the demux and a front-end previously connected by a
connect_frontend() call.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int disconnect_frontend(dmx_demux_t&#x22C6; demux);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>dmx_demux_t*
demux</para>
</entry><entry
align="char">
<para>Pointer to the demux API and instance data.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>RETURNS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>0</para>
</entry><entry
align="char">
<para>The function was completed without errors.</para>
</entry>
</row><row><entry
align="char">
<para>-EINVAL</para>
</entry><entry
align="char">
<para>Bad parameter.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section></section>
<section id="demux_callback_api">
<title>Demux Callback API</title>
<para>This kernel-space API comprises the callback functions that deliver filtered data to the
......
drivers/media/dvb-core/demux.h
View file @ 95abfdb9
......@@ -202,10 +202,197 @@ 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
* -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;
* -ENOSYS, if the command is not implemented;
* -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;
* -EBUSY, if no more TS feeds is available;
* -ENOSYS, if the command is not implemented;
* -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;
* -ENOSYS, if the command is not implemented;
* -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;
* -EEXIST, if a front-end with the same value of the id field
* already registered;
* -EINUSE, if the demux is in use;
* -ENOMEM, if no more front-ends can be added;
* -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;
* -EBUSY, if the front-end is in use, i.e. a call to
* connect_frontend() has not been followed by a call to
* disconnect_frontend();
* -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
* dmx_frontend_t*. 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;
* -EBUSY, if the front-end is in use;
* -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.
*/
struct dmx_demux {
u32 capabilities; /* Bitfield of capability flags */
struct dmx_frontend* frontend; /* Front-end connected to the demux */
void* priv; /* Pointer to private data of the API client */
u32 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);
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7