On 20/03/2024 17:42, Péter Ujfalusi wrote: >>> On 15/03/2024 13:27, Bastien Curutchet wrote: >>>> The McBSP's DX pin that outputs serial data during playback streams can >>>> be used during capture streams to repeatedly output a chosen pattern. >>>> For instance, this can be useful to drive an active-low signal during >>>> captures (by choosing <0> as output pattern). >>> >>> Are there really any other use of this than to pull down or up the DX >>> pin (0 or 0xffff) >> >> I don't know, indeed today I can only think about these two patterns. >> I tried to do something in a 'generic' way so it can evolve if needed. > > I think the definition of the 'ti,drive-dx' is somehow odd. It allows > you to set it to 0x1234 and the DX pin will show 0x1234 when you capture > 32bit. If you capture 16bit then it will transmit 0x12 (or 0x34?), no? > If you have 4 channel capture then I won't speculate what will be on the > DX pin ;) > > Would not be better to say that the DX pin will be driven low or high > during capture _and_ disable the playback support? After some thinking, it might be still better to use the DX pin as GPIO and either have a custom machine driver which would handle it (set low when a capture trigger happens) or connect it in DAPM as a supply, bias or something and ASoC would handle it automagically. I think that would be cleaner in many ways. What do you think? -- Péter
