Hi Rob,

On 2021/8/25 1:06, Rob Herring wrote:

On Tue, Aug 24, 2021 at 05:17:57PM +0800, Sugar Zhang wrote:

quoted

This patch documents property for playback-only and capture-only.

Signed-off-by: Sugar Zhang <redacted>
---

Changes in v2: None

  Documentation/devicetree/bindings/sound/rockchip-i2s.yaml | 10 ++++++++++
  1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/sound/rockchip-i2s.yaml b/Documentation/devicetree/bindings/sound/rockchip-i2s.yaml
index 9f9cc48..005b6e6 100644
--- a/Documentation/devicetree/bindings/sound/rockchip-i2s.yaml
+++ b/Documentation/devicetree/bindings/sound/rockchip-i2s.yaml

@@ -81,6 +81,16 @@ properties:
      description:
        Max playback channels, if not set, 8 channels default.
  
+  rockchip,capture-only:
+    type: boolean
+    description:
+      Specify that the controller has capture only capability.
+
+  rockchip,playback-only:
+    type: boolean
+    description:
+      Specify that the controller has playback only capability.

In the Rockchip TDM-I2S binding[1], these were dropped. Perhaps comment
there why they are needed.

It was used to specify the controller capatiblity, some controller has 
capture or playback only.

maybe we can implement it by judge property 'dma-names'.  such as:

of_property_for_each_string(np, "dma-names", dma_names, name)

if (!strcmp(name, "tx"))

     has capture capability...

if (!strcmp(name, "rx"))

     has capture capability...

will do in v3.

Rob

[1] https://lore.kernel.org/lkml/20210820182731.29370-1-frattaroli.nicolas@gmail.com/ (local)

-- 
Best Regards!
张学广/Sugar
瑞芯微电子股份有限公司
Rockchip Electronics Co., Ltd.