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Commit 725da8de authored by David S. Miller's avatar David S. Miller
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parents ce78c76f ddb5388f
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@@ -1507,6 +1507,14 @@ S: 312/107 Canberra Avenue
S: Griffith, ACT 2603 
S: Australia

N: Andreas Herrmann
E: herrmann.der.user@gmail.com
E: herrmann.der.user@googlemail.com
D: Key developer of x86/AMD64
D: Author of AMD family 15h processor power monitoring driver
D: Maintainer of AMD Athlon 64 and Opteron processor frequency driver
S: Germany

N: Sebastian Hetze
E: she@lunetix.de
D: German Linux Documentation,
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@@ -238,78 +238,26 @@ X!Isound/sound_firmware.c
!Iinclude/media/videobuf2-memops.h
     </sect1>
     <sect1><title>Digital TV (DVB) devices</title>
!Idrivers/media/dvb-core/dvb_ca_en50221.h
!Idrivers/media/dvb-core/dvb_frontend.h
	<sect1><title>Digital TV Common functions</title>
!Idrivers/media/dvb-core/dvb_math.h
!Idrivers/media/dvb-core/dvb_ringbuffer.h
!Idrivers/media/dvb-core/dvbdev.h
	<sect1><title>Digital TV Demux API</title>
	    <para>The kernel demux API defines a driver-internal interface for
	    registering low-level, hardware specific driver to a hardware
	    independent demux layer. It is only of interest for Digital TV
	    device driver writers. The header file for this API is named
	    <constant>demux.h</constant> and located in
	    <constant>drivers/media/dvb-core</constant>.</para>

	<para>The demux API should be implemented for each demux in the
	system. It is used to select the TS source of a demux and to manage
	the demux resources. When the demux client allocates a resource via
	the demux API, it receives a pointer to the API of that
	resource.</para>
	<para>Each demux receives its TS input from a DVB front-end or from
	memory, as set via this demux API. In a system with more than one
	front-end, the API can be used to select one of the DVB front-ends
	as a TS source for a demux, unless this is fixed in the HW platform.
	The demux API only controls front-ends regarding to their connections
	with demuxes; the APIs used to set the other front-end parameters,
	such as tuning, are not defined in this document.</para>
	<para>The functions that implement the abstract interface demux should
	be defined static or module private and registered to the Demux
	core for external access. It is not necessary to implement every
	function in the struct <constant>dmx_demux</constant>. For example,
	a demux interface might support Section filtering, but not PES
	filtering. The API client is expected to check the value of any
	function pointer before calling the function: the value of NULL means
	that the &#8220;function is not available&#8221;.</para>
	<para>Whenever the functions of the demux API modify shared data,
	the possibilities of lost update and race condition problems should
	be addressed, e.g. by protecting parts of code with mutexes.</para>
	<para>Note that functions called from a bottom half context must not
	sleep. Even a simple memory allocation without using GFP_ATOMIC can
	result in a kernel thread being put to sleep if swapping is needed.
	For example, the Linux kernel calls the functions of a network device
	interface from a bottom half context. Thus, if a demux API function
	is called from network device code, the function must not sleep.
	</para>
	</sect1>

    <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 demux client. Unlike the other DVB
	kABIs, these functions are provided by the client and called from
	the demux code.</para>
	<para>The function pointers of this abstract interface are not
	packed into a structure as in the other demux APIs, because the
	callback functions are registered and used independent of each
	other. As an example, it is possible for the API client to provide
	several callback functions for receiving TS packets and no
	callbacks for PES packets or sections.</para>
	<para>The functions that implement the callback API need not be
	re-entrant: when a demux driver calls one of these functions,
	the driver is not allowed to call the function again before
	the original call returns. If a callback is triggered by a
	hardware interrupt, it is recommended to use the Linux
	&#8220;bottom half&#8221; mechanism or start a tasklet instead of
	making the callback function call directly from a hardware
	interrupt.</para>
	<para>This mechanism is implemented by
	<link linkend='API-dmx-ts-cb'>dmx_ts_cb()</link> and
	<link linkend='API-dmx-section-cb'>dmx_section_cb()</link>.</para>
    </section>

	<sect1><title>Digital TV Frontend kABI</title>
!Pdrivers/media/dvb-core/dvb_frontend.h Digital TV Frontend
!Idrivers/media/dvb-core/dvb_frontend.h
	</sect1>
	<sect1><title>Digital TV Demux kABI</title>
!Pdrivers/media/dvb-core/demux.h Digital TV Demux
	<sect1><title>Demux Callback API</title>
!Pdrivers/media/dvb-core/demux.h Demux Callback
	</sect1>
!Idrivers/media/dvb-core/demux.h
	</sect1>
	<sect1><title>Digital TV Conditional Access kABI</title>
!Idrivers/media/dvb-core/dvb_ca_en50221.h
	</sect1>
     </sect1>
    <sect1><title>Remote Controller devices</title>
!Iinclude/media/rc-core.h
!Iinclude/media/lirc_dev.h
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@@ -199,8 +199,10 @@ DVB_DOCUMENTED = \
#

install_media_images = \
	$(Q)-mkdir $(MEDIA_OBJ_DIR)/media_api; \
	cp $(OBJIMGFILES) $(MEDIA_SRC_DIR)/*.svg $(MEDIA_SRC_DIR)/v4l/*.svg $(MEDIA_OBJ_DIR)/media_api
	$(Q)if [ "x$(findstring media_api.xml,$(DOCBOOKS))" != "x" ]; then \
		mkdir -p $(MEDIA_OBJ_DIR)/media_api; \
		cp $(OBJIMGFILES) $(MEDIA_SRC_DIR)/*.svg $(MEDIA_SRC_DIR)/v4l/*.svg $(MEDIA_OBJ_DIR)/media_api; \
	fi

$(MEDIA_OBJ_DIR)/%: $(MEDIA_SRC_DIR)/%.b64
	$(Q)base64 -d $< >$@
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@@ -76,7 +76,7 @@ int main(void)

<para>NOTE: While it is possible to directly call the Kernel code like the
    above example, it is strongly recommended to use
    <ulink url="http://linuxtv.org/docs/libdvbv5/index.html">libdvbv5</ulink>,
    <ulink url="https://linuxtv.org/docs/libdvbv5/index.html">libdvbv5</ulink>,
    as it provides abstraction to work with the supported digital TV standards
    and provides methods for usual operations like program scanning and to
    read/write channel descriptor files.</para>
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@@ -3,7 +3,7 @@
</para>
<para>NOTE: This section is out of date, and the code below won't even
    compile. Please refer to the
    <ulink url="http://linuxtv.org/docs/libdvbv5/index.html">libdvbv5</ulink>
    <ulink url="https://linuxtv.org/docs/libdvbv5/index.html">libdvbv5</ulink>
    for updated/recommended examples.
</para>

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