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authorStephan Gerhold <stephan@gerhold.net>2020-04-25 21:46:56 +0300
committerMark Brown <broonie@kernel.org>2020-05-05 15:17:21 +0300
commitd5797ede0818b24252f79497e1c7e1245c328f6b (patch)
treeb08c973267bc25cb5c1b0d72533594cd8b59784d /Documentation
parentdbab677f324dcf26dc8c443e3ff39a4eaa6dcacc (diff)
downloadlinux-d5797ede0818b24252f79497e1c7e1245c328f6b.tar.xz
dt-bindings: sound: lpass-cpu: Document DAI subnodes
The lpass-cpu driver now allows configuring the MI2S SD lines by defining subnodes for one of the DAIs. Document this in the device tree bindings. Signed-off-by: Stephan Gerhold <stephan@gerhold.net> Link: https://lore.kernel.org/r/20200425184657.121991-1-stephan@gerhold.net Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/sound/qcom,lpass-cpu.txt25
1 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/sound/qcom,lpass-cpu.txt b/Documentation/devicetree/bindings/sound/qcom,lpass-cpu.txt
index 21c648328be9..32c2cdb3d32f 100644
--- a/Documentation/devicetree/bindings/sound/qcom,lpass-cpu.txt
+++ b/Documentation/devicetree/bindings/sound/qcom,lpass-cpu.txt
@@ -30,6 +30,8 @@ Required properties:
- reg : Must contain an address for each entry in reg-names.
- reg-names : A list which must include the following entries:
* "lpass-lpaif"
+- #address-cells : Must be 1
+- #size-cells : Must be 0
@@ -37,6 +39,20 @@ Optional properties:
- qcom,adsp : Phandle for the audio DSP node
+By default, the driver uses up to 4 MI2S SD lines, for a total of 8 channels.
+The SD lines to use can be configured by adding subnodes for each of the DAIs.
+
+Required properties for each DAI (represented by a subnode):
+- reg : Must be one of the DAI IDs
+ (usually part of dt-bindings header)
+- qcom,playback-sd-lines: List of serial data lines to use for playback
+ Each SD line should be represented by a number from 0-3.
+- qcom,capture-sd-lines : List of serial data lines to use for capture
+ Each SD line should be represented by a number from 0-3.
+
+Note that adding a subnode changes the default to "no lines configured",
+so both playback and capture lines should be configured when a subnode is added.
+
Example:
lpass@28100000 {
@@ -51,4 +67,13 @@ lpass@28100000 {
reg = <0x28100000 0x10000>;
reg-names = "lpass-lpaif";
qcom,adsp = <&adsp>;
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ /* Optional to set different MI2S SD lines */
+ dai@3 {
+ reg = <MI2S_QUATERNARY>;
+ qcom,playback-sd-lines = <0 1>;
+ };
};