On 05/12/2022 09:00, Geert Uytterhoeven wrote:
Hi Krzysztof,
Thanks for your comments!
On Sat, Dec 3, 2022 at 1:13 PM Krzysztof Kozlowski krzysztof.kozlowski@linaro.org wrote:
On 02/12/2022 13:55, Geert Uytterhoeven wrote:
Convert the Texas Instruments PCM3168A Audio Codec Device Tree binding documentation to json-schema.
Add missing properties. Drop unneeded pinctrl properties from example.
Thank you for your patch. There is something to discuss/improve.
+description:
- The Texas Instruments PCM3168A is a 24-bit Multi-channel Audio CODEC with
- 96/192kHz sampling rate, supporting both SPI and I2C bus access.
+properties:
- compatible:
- const: ti,pcm3168a
- reg:
- maxItems: 1
- clocks:
- items:
- description: System clock input- clock-names:
- items:
- const: scki- reset-gpios:
- items:
- description: |GPIO line connected to the active-low RST pin of the codec.RST = low: device power-downRST = high: device is enabled- "#sound-dai-cells":
- enum: [0, 1]
This is a bit unexpected. Looking at DTSes:
- I see in ulcb-kf.dtsi with cells==0, but two endpoints. The dai cells
seem unused? In such case shall dai-cells be skipped if we have endpoints?
- in k3-j721e-common-proc-board.dts has cells=1, but user's phandle
does not have an argument, so practically it is ==0? The user - sound/soc/ti/j721e-evm.c - just gets the node and does not use cells, right? So even though dai-cells==1, it does not matter, because user gets its own parsing?
- The pcm3168a driver also does not have any xlate function, but it
registers to DAIs, so all uses should be with cells==1 to select proper DAI...
I have no idea (DAI is magic to me), and hope the audio experts can provide some input...
It is a bit of magic to me too. Yet I think the correct usage of this is with dai-cells=1. I think we can skip the choice here between sound-dai-cells and endpoints (to allow only one) and only fix the value here to =1.
This would also require changing arch/arm64/boot/dts/renesas/ulcb-kf.dtsi to dai-cells=1.
Best regards, Krzysztof