[PATCH v3] ASoC: dt-bindings: imx-card: Add dsp_a DAI format

[Chancel Liu]

Existing i.MX audio sound card described by this binding use codecs
that operate in i2s or dsp_b formats. The newly added CS42448 codec
requires dsp_a for its TDM interface. To properly describe such
hardware in DT, the binding needs to allow dsp_a DAI format.

Only i2s, dsp_b and dsp_a are included because these are the formats
actually used by the hardware supported by this binding. Other formats
such as left_j, right_j, ac97 are not used or required by the hardware
currently covered by this binding, so they are intentionally not added.

Signed-off-by: Chancel Liu <chancel.liu@xxxxxxx>
---
Changes in v3:
- Rewrote commit message completely to describe hardware requirements.
Explicitly documented why only dsp_a is added and why other formats
are not included.
- Rebased on latest code base. No functional changes.

Changes in v2:
- Updated commit message to explain current support for i2s and dsp_b
formats and new support for dsp_a. No code changes.

 Documentation/devicetree/bindings/sound/imx-audio-card.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/sound/imx-audio-card.yaml b/Documentation/devicetree/bindings/sound/imx-audio-card.yaml
index 5424d4f16f52..75757fbccd89 100644
--- a/Documentation/devicetree/bindings/sound/imx-audio-card.yaml
+++ b/Documentation/devicetree/bindings/sound/imx-audio-card.yaml
@@ -37,6 +37,7 @@ patternProperties:
         items:
           enum:
             - i2s
+            - dsp_a
             - dsp_b

       dai-tdm-slot-num: true
--
2.50.1