Both the capture and playback channels are optional in the axi_i2s IP block. Document how to tell the driver which channels are instantiated. Signed-off-by: Luca Ceresoli <luca@xxxxxxxxxxxxxxxx> --- Documentation/devicetree/bindings/sound/adi,axi-i2s.txt | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/sound/adi,axi-i2s.txt b/Documentation/devicetree/bindings/sound/adi,axi-i2s.txt index 4248b662deff..229ad1392cdc 100644 --- a/Documentation/devicetree/bindings/sound/adi,axi-i2s.txt +++ b/Documentation/devicetree/bindings/sound/adi,axi-i2s.txt @@ -1,5 +1,8 @@ ADI AXI-I2S controller +The core can be generated with transmit (playback), only receive +(capture) or both directions enabled. + Required properties: - compatible : Must be "adi,axi-i2s-1.00.a" - reg : Must contain I2S core's registers location and length @@ -9,8 +12,8 @@ Required properties: - clock-names : "axi" for the clock to the AXI interface, "ref" for the sample rate reference clock. - dmas: Pairs of phandle and specifier for the DMA channels that are used by - the core. The core expects two dma channels, one for transmit and one for - receive. + the core. The core expects two dma channels if both transmit and receive are + enabled, one channel otherwise. - dma-names : "tx" for the transmit channel, "rx" for the receive channel. For more details on the 'dma', 'dma-names', 'clock' and 'clock-names' properties -- 2.17.1