Re: [PATCH v4 1/9] ASoC: dt-bindings: wcd938x: add bindings for wcd938x

From: Srinivas Kandagatla
Date: Fri Apr 30 2021 - 04:20:25 EST


Hi Rob,

On 15/04/2021 17:53, Srinivas Kandagatla wrote:
Thanks Rob for quick review,

On 15/04/2021 17:29, Rob Herring wrote:
On Wed, Apr 14, 2021 at 04:48:37PM +0100, Srinivas Kandagatla wrote:
Qualcomm WCD9380/WCD9385 Codec is a standalone Hi-Fi audio codec IC
connected over SoundWire. This device has two SoundWire device RX and
TX respectively, supporting 4 x ADCs, ClassH, Ear, Aux PA, 2xHPH,
7 x TX diff inputs, 8 DMICs, MBHC.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
  .../bindings/sound/qcom,wcd938x.yaml          | 176 ++++++++++++++++++
  1 file changed, 176 insertions(+)
  create mode 100644 Documentation/devicetree/bindings/sound/qcom,wcd938x.yaml

diff --git a/Documentation/devicetree/bindings/sound/qcom,wcd938x.yaml b/Documentation/devicetree/bindings/sound/qcom,wcd938x.yaml
new file mode 100644
index 000000000000..4c8fa8290af0
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/qcom,wcd938x.yaml
@@ -0,0 +1,176 @@

...

+additionalProperties: false
+
+examples:
+  - |
+    codec {
+        compatible = "qcom,wcd9380-codec";
+        reset-gpios = <&tlmm 32 0>;
+        #sound-dai-cells = <1>;
+        qcom,tx-device = <&wcd938x_tx>;
+        qcom,rx-device = <&wcd938x_rx>;
+        qcom,micbias1-microvolt = <1800000>;
+        qcom,micbias2-microvolt = <1800000>;
+        qcom,micbias3-microvolt = <1800000>;
+        qcom,micbias4-microvolt = <1800000>;
+        qcom,mbhc-hphl-switch;
+        qcom,mbhc-ground-switch;
+        qcom,mbhc-button0-vthreshold-microvolt = <75000>;
+        qcom,mbhc-button1-vthreshold-microvolt = <150000>;
+        qcom,mbhc-button2-vthreshold-microvolt = <237000>;
+        qcom,mbhc-button3-vthreshold-microvolt = <500000>;
+        qcom,mbhc-button5-vthreshold-microvolt = <500000>;
+        qcom,mbhc-button6-vthreshold-microvolt = <500000>;
+        qcom,mbhc-button7-vthreshold-microvolt = <500000>;
+    };
+
+    /* ... */
+
+    soundwire@3230000 {
+        #address-cells = <2>;
+        #size-cells = <0>;
+        reg = <0x03230000 0x2000>;
+        wcd938x_tx: codec@0,3 {
+            compatible = "sdw20217010d00";
+            reg  = <0 3>;
+            qcom,direction = "tx";
+            qcom,port-mapping = <2 3 4 5>;
+        };
+
+        wcd938x_rx: codec@0,4 {
+            compatible = "sdw20217010d00";
+            reg  = <0 4>;
+            qcom,direction = "rx";
+            qcom,port-mapping = <1 2 3 4 5>;
+        };

This is a single device, right? We shouldn't need 3 nodes to describe
it. I think this should all be a single node like this:

No, WCD938x is a Audio Codec which has two SoundWire Slave device (TX and RX). WCD938X reset lines and supplies are common for both TX and RX SoundWire devices.

However TX SoundWire device only has register access to codec CSR(Control Status registers).

So there are two SoundWire devices and a WCD938X common parts. Now making the common Codec part as a separate device made more sense here.
So we ended with total 3 devices.

1 . WCD938x Codec which deals with all the codec side including Common parts.
2. TX SoundWire device to configure TX SoundWire ports/interface and provide CSR access.
3. RX SoundWire device to configure RX Soundwire ports/interface



Are you okay with the existing device layout after providing the above information?


codec {
compatible = "qcom,wcd9380-codec";
reset-gpios = <&tlmm 32 0>;
#sound-dai-cells = <1>;
qcom,tx-device = <&wcd938x_tx>;
qcom,rx-device = <&wcd938x_rx>;
qcom,micbias1-microvolt = <1800000>;
qcom,micbias2-microvolt = <1800000>;
qcom,micbias3-microvolt = <1800000>;
qcom,micbias4-microvolt = <1800000>;
qcom,mbhc-hphl-switch;
qcom,mbhc-ground-switch;
qcom,mbhc-button0-vthreshold-microvolt = <75000>;
qcom,mbhc-button1-vthreshold-microvolt = <150000>;
qcom,mbhc-button2-vthreshold-microvolt = <237000>;
qcom,mbhc-button3-vthreshold-microvolt = <500000>;
qcom,mbhc-button5-vthreshold-microvolt = <500000>;
qcom,mbhc-button6-vthreshold-microvolt = <500000>;
qcom,mbhc-button7-vthreshold-microvolt = <500000>;
};


soundwire-controller@3230000 {
reg = <0 0x3230000 0 0x2000>;
compatible = "qcom,soundwire-v1.5.1";
wcd938x_tx: codec@0,3 {
compatible = "sdw20217010d00";
reg = <0 3>;
qcom,direction = "tx";
qcom,port-mapping = <2 3 4 5>;
};
};


soundwire-controller@3210000 {
reg = <0 0x3210000 0 0x2000>;
compatible = "qcom,soundwire-v1.5.1";
wcd938x_rx: codec@0,4 {
compatible = "sdw20217010d00";
reg = <0 4>;
qcom,direction = "rx";
qcom,port-mapping = <1 2 3 4 5>;
};
};


thanks,
srini



codec@0,3 {
         reg = <0 3>, <0 4>;

We can't have this, as these two SoundWire devices hang on different SoundWire bus instances.

    compatible = "sdw20217010d00";

         reset-gpios = <&tlmm 32 0>;
         #sound-dai-cells = <1>;
         qcom,micbias1-microvolt = <1800000>;
         qcom,micbias2-microvolt = <1800000>;
         qcom,micbias3-microvolt = <1800000>;
         qcom,micbias4-microvolt = <1800000>;
         qcom,mbhc-hphl-switch;
         qcom,mbhc-ground-switch;
         qcom,mbhc-button0-vthreshold-microvolt = <75000>;
         qcom,mbhc-button1-vthreshold-microvolt = <150000>;
         qcom,mbhc-button2-vthreshold-microvolt = <237000>;
         qcom,mbhc-button3-vthreshold-microvolt = <500000>;
         qcom,mbhc-button5-vthreshold-microvolt = <500000>;
         qcom,mbhc-button6-vthreshold-microvolt = <500000>;
         qcom,mbhc-button7-vthreshold-microvolt = <500000>;
};

You'll have to figure out the qcom,direction and qcom,port-mapping parts
though.

That is the reason why we ended up with 3 devices here.

--srini

Rob