Messages in this thread | | | Date | Mon, 12 Jan 2015 12:25:27 +0000 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH v9 1/4] drm/i2c: tda998x: Add DT support for audio |
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On Mon, Jan 12, 2015 at 10:25:28AM +0100, Philipp Zabel wrote: > Jean-Francois' reply already reflects this, but the 'port' nodes should > correspond to physical ports of the device if possible. If you can > configure the device to have dedicated input pins for I2S, SPDIF0, and > SPDIF1 at the same time, they should appear in the device tree as > separate ports: > > tda998x: hdmi-encoder { > port@0 { /* pixel data according to video-ports */ > reg = <0x00>; > }; > port@1 { /* AP1: SPDIF0 */ > reg = <0x01>; > }; > port@2 { /* AP2: SPDIF1 */ > reg = <0x02>; > }; > port@3 { /* AP3: I2S */ > reg = <0x03>; > }; > }; > > The tda998x binding would define how the ports are numbered, some > correspondence to the AP pin numbers would be good.
It's not quite that simple, because the SPDIF AP pins are multiplexed with the I2S pins - and there is variation between chip models and packages.
So, it's probably best if port@0 is the video port, and then port@1..n can describe the audio inputs, including a property which specifies whether they are I2S or SPDIF, and the value to be programmed into the AP enable register (which is a bit field of the AP pins which should be unmasked.) I guess we can re-use the reg= property for that value, since video will always be zero.
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