From: Stefano Radaelli <stefano.r@variscite.com>
The simple-audio-card driver can program sysclk for CPU and codec DAIs
during hw_params. Some setups require calling the CPU DAI sysclk first
so that the codec sees the final MCLK rate.
Document a new boolean DT flag, sysclk-cpu-first, which allows selecting
CPU-first sysclk ordering where needed. The property is supported both
as a top-level simple-audio-card property (prefixed) and on dai-link
subnodes (non-prefixed).
Signed-off-by: Stefano Radaelli <stefano.r@variscite.com>
---
.../devicetree/bindings/sound/simple-card.yaml | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/simple-card.yaml b/Documentation/devicetree/bindings/sound/simple-card.yaml
index 533d0a1da56e..ddad440636be 100644
--- a/Documentation/devicetree/bindings/sound/simple-card.yaml
+++ b/Documentation/devicetree/bindings/sound/simple-card.yaml
@@ -35,6 +35,13 @@ definitions:
description: see tdm-slot.txt.
$ref: /schemas/types.yaml#/definitions/uint32
+ sysclk-cpu-first:
+ description:
+ When mclk-fs is used, configure CPU DAI sysclk before codec DAI sysclk
+ so the codec sees the final MCLK rate.
+ This property only affects the mclk-fs code path.
+ $ref: /schemas/types.yaml#/definitions/flag
+
system-clock-frequency:
description: |
If a clock is specified and a multiplication factor is given with
@@ -194,6 +201,8 @@ properties:
$ref: "#/definitions/format"
simple-audio-card,mclk-fs:
$ref: "#/definitions/mclk-fs"
+ simple-audio-card,sysclk-cpu-first:
+ $ref: "#/definitions/sysclk-cpu-first"
simple-audio-card,aux-devs:
$ref: "#/definitions/aux-devs"
simple-audio-card,additional-devs:
@@ -251,6 +260,8 @@ patternProperties:
$ref: "#/definitions/format"
mclk-fs:
$ref: "#/definitions/mclk-fs"
+ sysclk-cpu-first:
+ $ref: "#/definitions/sysclk-cpu-first"
aux-devs:
$ref: "#/definitions/aux-devs"
convert-rate:
--
2.47.3