[alsa-devel] [PATCH v9 1/4] drm/i2c: tda998x: Add DT support for audio

[Andrew Jackson]

On 01/08/15 20:04, Mark Brown wrote:
> On Thu, Jan 08, 2015 at 05:42:57PM +0100, Jean-Francois Moine wrote:
> 
>> Examples:
> 
>> - for the Cubox:
> 
>> 	audio-inputs = "i2s", "spdif";
> 
>> - for some other board with I2S on the pins 3 and 4 only:
> 
>> 	audio-inputs = "none", "none", "i2s", "i2s";
> 
>> - for a fully wired TDA9983B (no driver yet):
> 
>> 	audio-inputs = "i2s", "i2s", "i2s", "i2s", "spdif";
> 
> I think that mostly works, though I do wonder if we need a way to
> specify the ordering of the pins (if you can make pin 3 be the first two
> I2S channels for example)?  Someone might choose a strange mapping for
> board routing reasons for example.
> 

If it helps, I've collated the pin assignments given in the various TDA datasheets that I can find:

Chip>	9983B	9989		19988		19989	
Mode>	-	S/PDIF	I2S	S/PDIF	I2S	S/PDIF	I2S
Pin
AP0	WS	-	WS	-	WS	-	WS
AP1	I2S#0	S/PDIF	I2S#0	S/PDIF	I2S#0	S/PDIF	I2S#0
AP2	I2S#1	-	-	S/PDIF	I2S#1	S/PDIF	I2S#1
AP3	I2S#2	-	-	-	I2S#2*	MCLK	-
AP4	I2S#3	-	-	-	I2S#3*	-	-
AP5	MCLK	-	-	-	-	-	-
AP6	S/PDIF	-	-	-	-	-	-
AP7	AUX	-	-	-	-	-	-

WS = I2S Word Select
* Depends on package

The 9983B differs from the other devices in that the I2S and S/PDIF functionality is not multiplexed 
onto various pins.

	Andrew