On 01/08/2015 06:42 PM, Jean-Francois Moine wrote:
On Thu, 8 Jan 2015 16:53:41 +0200
Jyri Sarha <jsarha@xxxxxx> wrote:
+ - audio-ports: must contain one or two values selecting the source
+ in the audio port.
+ The source type is given by the corresponding entry in
+ the audio-port-names property.
+
This binding does not allow multi channel i2s setups with multiple i2s
pins. It would be nice to support that in the DT binding, even if the
code is not yet ready for it.
How about having these two optional properties instead of audio-ports
and audio-port-names:
audio-port-i2s: Upto 4 values for selecting pins for i2s port
audio-port-spdif: Value for selecting input pin for spdif port
Presence of one of the properties would be mandatory and both are allowed.
Sorry to notice this only now, but I have not yet looked the drm side
changes too closely.
From Andrew's datasheet, the TDA998x's which are handled by the tda998x
driver have only 4 input audio pins, the first two ones being either
S/PDIF or I2s, the last ones being I2S only.
AFAIK, SPDIF is always a single pin connection so only one pin needs to
be selected. But i2s need for pins for full 8 channel output.
So, the DT description could be reduced to a simple list indexed by
the pin number (= DAI number) and defining the protocol type.
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";
If you want to go closer to the original paradigm, then how about
defining following audio-port-names: i2s0, i2s1, i2s2, i2s3, and spdif.
With this approach we could go with your original binding with only
minor changes. A binding in your stereo i2s or spdif case would look
like this:
audio-ports = <0x04>, <0x03>;
audio-port-names = "spdif", "i2s0";
A full 8 channel i2s or spdif output would look like this:
audio-ports = <0x04>, <0x03>, <0x02>, <0x01>, <0x00>;
audio-port-names = "spdif", "i2s0", "i2s1", "i2s2", "i2s3";
This would also indicate the channel mapping to the audio pins (i2s0 for
first two channels, i2s1 for 3-4, etc.)
The code could for now just look for "i2s0" and the port names for
channels 3-8 could be ignored until they are needed.
Best regards,
Jyri
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