Hi Lars, On 11-04-2016 10:33, Lars-Peter Clausen wrote: > On 04/11/2016 11:27 AM, Jose Abreu wrote: >> Hi Lars, >> >> >> On 09-04-2016 16:02, Lars-Peter Clausen wrote: >>> On 04/08/2016 06:12 PM, Jose Abreu wrote: >>> [...] >>>>> [...] >>>>>> +- adi,enable-audio: If set the ADV7511 driver will register a codec interface >>>>>> + into ALSA SoC. >>>>> This is not a description of the hardware. >>>> Is this okay: "adi,enable-audio: Set this boolean parameter if ADV7511 >>>> transmitter routes audio signals" ? >>> I don't think we need this property. There is no problem with registering >>> the audio part unconditionally. As long as there is no connection we wont >>> create a sound card that is exposed to userspace. >>> >> This change was suggested by Laurent Pinchart and was introduced in v3. Quoting >> Laurent: >> "The idea is that enabling support for ADV7511 audio in the kernel isn't coupled >> with whether the system includes audio support. It would be confusing, and would >> also waste resources, to create a Linux sound device when no sound channel is >> routed on the board." > I wouldn't care too much about this at this point, the extra amount of > resources required for registering the CODEC (but not the sound card) is > just a few bytes (sizeof(struct snd_soc_codec)). > > Nevertheless what we should do is describe the hardware and from this > information infer whether there is a audio connection or not and if there is > none we might skip registering the CODEC. In my opinion this hardware > description should be modeled using of-graph, having a connection between > the SoC side and the adv7511 SPDIF or I2S port. > You mean something like this: sound_playback: sound_playback { compatible = "simple-audio-card"; [...] simple-audio-card,format = "i2s"; [...] } adv7511 at xx { compatible = "adi,adv7511"; [...] ports { [...] /* Audio Output */ port at x { reg = <x>; endpoint { remote-endpoint = <&sound_playback>; } } } } ? Best regards, Jose Miguel Abreu