McBSP's data delay can be configured from 0 to 2 bit clock periods. 0 is used for DSP_B format, 1 for DSP_A format. A data delay of 2 bit clock periods can be used to interface to 'T1 framing' devices where data stream is preceded by a 'framing bit'. This 2 bit clock data delay is not described in the bindings.
Add two flags 'ti,T1-framing-[rx/tx]' to enable a data delay of 2 bit clock periods in reception or transmission.
Signed-off-by: Bastien Curutchet bastien.curutchet@bootlin.com --- .../devicetree/bindings/sound/davinci-mcbsp.yaml | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml b/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml index 0c2b1936c6a1..4fa677023827 100644 --- a/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml +++ b/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml @@ -67,6 +67,20 @@ properties: "#sound-dai-cells": const: 0
+ ti,T1-framing-tx: + $ref: /schemas/types.yaml#/definitions/flag + description: + If the property is present, tx data delay is set to 2 bit clock periods. + McBSP will insert a blank period (high-impedance period) before the first + data bit. This can be used to interface to T1-framing devices. + + ti,T1-framing-rx: + $ref: /schemas/types.yaml#/definitions/flag + description: + If the property is present, rx data delay is set to 2 bit clock periods. + McBSP will discard the bit preceding the data stream (called framing bit). + This can be used to interface to T1-framing devices. + required: - "#sound-dai-cells" - compatible