Hello Conor,
On 9. 5. 2023, at 20:25, Conor Dooley conor@kernel.org wrote:
Hey Martin,
On Tue, May 09, 2023 at 06:38:27PM +0200, Martin Povišer wrote:
Add a DT schema for the SSM3515 amp by Analog Devices. It's a simple mono amplifier with digital input.
Signed-off-by: Martin Povišer povik+lin@cutebit.org
.../bindings/sound/adi,ssm3515.yaml | 66 +++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 Documentation/devicetree/bindings/sound/adi,ssm3515.yaml
diff --git a/Documentation/devicetree/bindings/sound/adi,ssm3515.yaml b/Documentation/devicetree/bindings/sound/adi,ssm3515.yaml new file mode 100644 index 000000000000..19b7185ae8e2 --- /dev/null +++ b/Documentation/devicetree/bindings/sound/adi,ssm3515.yaml @@ -0,0 +1,66 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +# Copyright (C) 2019-20 Texas Instruments Incorporated
Copyright here looks a little odd, copy & paste from the TI bindings you send patches for earlier, or intended?
Yeah, that must have been a copypaste from the other schemas. Not intended in any case. Thanks for the catch.
+%YAML 1.2 +--- +$id: "http://devicetree.org/schemas/sound/adi,ssm3515.yaml#" +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
Drop the quotes on these please.
OK
- adi,ana-gain:
- $ref: /schemas/types.yaml#/definitions/uint32
- enum: [0, 1, 2, 3]
- description: |
The value to be set in the ANA_GAIN register field on the codec. This determinesthe full voltage span of the codec's analog output.To quote the datasheet on the available options:00: 8.4 V Full-Scale Gain Mapping01: 12.6 V Full-Scale Gain Mapping10: 14 V Full-Scale Gain Mapping11: 15 V Full-Scale Gain MappingPutting register values into the DT does not seem correct, although I know nothing about sound and will have to defer to Krzysztof & Co. on that front.
It’s an analog gain selection, it just seemed most honest and convenient to defer to the register field in describing of what this property does.
I thought this should be here, and not with the other gain controls to be exported to userspace, since it relates to the supply voltage. You probably can’t select a gain value close or over the amp’s supply and expect proper functioning, so the value here should be the system’s integrator choice.
On second thought there doesn’t seem to be any risk of damage to the amp itself, so the knowledge of what’s the optimal value could be left up to ALSA use-case configuration, and there’s no real downside in treating it like other gain controls.
I think I will remove it in the next iteration.
Cheers, Conor.
Cheers, Martin