sound/soc/dapm.rst

19 DAPM is based on two basic elements, called widgets and routes:
23  * a **route** is an interconnection between widgets that exists when sound
28 the whole sound card, so some DAPM routes connect two widgets belonging to
69 DAPM Widgets
72 Audio DAPM widgets fall into a number of types:
99 	Power or clock supply widget used by other widgets.
139 (Widgets are defined in include/sound/soc-dapm.h)
141 Widgets can be added to the sound card by any of the component driver types.
143 build a list of widgets of the codecs and machines DAPM widgets.
145 Most widgets have a name, register, shift and invert. Some widgets have extra
149 Stream Domain Widgets
152 Stream Widgets relate to the stream power domain and only consist of ADCs
156 Stream widgets have the following format:
165 e.g. stream widgets for HiFi playback and capture
171 e.g. stream widgets for AIF
178 Path Domain Widgets
181 Path domain widgets have a ability to control or affect the audio signal or
207 Machine domain Widgets
210 Machine widgets are different from codec widgets in that they don't have a
236 The codec bias power domain has no widgets and is handled by the codec DAPM
241 Virtual Widgets
244 Sometimes widgets exist in the codec or machine audio graph that don't have any
256 In many cases the DAPM widgets are implemented statically in a ``static
290 In more complex cases the list of DAPM widgets and/or routes can be only
293 separate widgets and routes arrays implementing the case-specific features
301 Widgets are connected to each other within the codec, platform and machine by
303 order to create a graph of all audio paths between widgets.
306 audio system), as it requires joining widgets together via their audio signal
318 source widgets.  ::
331 When there is no path name connecting widgets (e.g. a direct connection) we
338 Finally, snd_soc_dapm_new_widgets() must be called after all widgets and
347 directly connect the codec pins to machine level widgets.
360 Endpoint Widgets
379 Widgets needing to implement a more complex behaviour than what DAPM can do
401 See soc-dapm.h for all other widgets that support events.
407 The following event types are supported by event widgets::