!Ekernel/time/hrtimer.c
</sect1>
<sect1><title>Workqueues and Kevents</title>
+!Iinclude/linux/workqueue.h
!Ekernel/workqueue.c
</sect1>
<sect1><title>Internal Functions</title>
-->
</chapter>
+ <chapter id="mediadev">
+ <title>Media Devices</title>
+
+ <sect1><title>Video2Linux devices</title>
+!Iinclude/media/tuner.h
+!Iinclude/media/tuner-types.h
+!Iinclude/media/tveeprom.h
+!Iinclude/media/v4l2-async.h
+!Iinclude/media/v4l2-ctrls.h
+!Iinclude/media/v4l2-dv-timings.h
+!Iinclude/media/v4l2-event.h
+!Iinclude/media/v4l2-flash-led-class.h
+!Iinclude/media/v4l2-mediabus.h
+!Iinclude/media/v4l2-mem2mem.h
+!Iinclude/media/v4l2-of.h
+!Iinclude/media/v4l2-subdev.h
+!Iinclude/media/videobuf2-core.h
+!Iinclude/media/videobuf2-v4l2.h
+!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
+!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 “function is not available”.</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
+ “bottom half” 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>
+
+!Idrivers/media/dvb-core/demux.h
+ </sect1>
+ <sect1><title>Remote Controller devices</title>
+!Iinclude/media/rc-core.h
+!Iinclude/media/lirc_dev.h
+ </sect1>
+ <sect1><title>Media Controller devices</title>
+!Iinclude/media/media-device.h
+!Iinclude/media/media-devnode.h
+!Iinclude/media/media-entity.h
+ </sect1>
+
+ </chapter>
+
<chapter id="uart16x50">
<title>16x50 UART Driver</title>
!Edrivers/tty/serial/serial_core.c
!Edrivers/hsi/hsi.c
</chapter>
+ <chapter id="pwm">
+ <title>Pulse-Width Modulation (PWM)</title>
+ <para>
+ Pulse-width modulation is a modulation technique primarily used to
+ control power supplied to electrical devices.
+ </para>
+ <para>
+ The PWM framework provides an abstraction for providers and consumers
+ of PWM signals. A controller that provides one or more PWM signals is
+ registered as <structname>struct pwm_chip</structname>. Providers are
+ expected to embed this structure in a driver-specific structure. This
+ structure contains fields that describe a particular chip.
+ </para>
+ <para>
+ A chip exposes one or more PWM signal sources, each of which exposed
+ as a <structname>struct pwm_device</structname>. Operations can be
+ performed on PWM devices to control the period, duty cycle, polarity
+ and active state of the signal.
+ </para>
+ <para>
+ Note that PWM devices are exclusive resources: they can always only be
+ used by one consumer at a time.
+ </para>
+!Iinclude/linux/pwm.h
+!Edrivers/pwm/core.c
+ </chapter>
+
</book>
Code Review / kvmfornfv.git / blobdiff