Re: [RFC v2 03/11] dt-bindings: iio: stm32-dfsdm-adc: add scaling support

From: Olivier MOYSAN
Date: Thu Aug 31 2023 - 11:53:44 EST

Hi Rob,

On 8/11/23 19:10, Rob Herring wrote:
On Thu, Jul 27, 2023 at 05:03:14PM +0200, Olivier Moysan wrote:
Add scaling support to STM32 DFSDM.

This introduces the following changes:

Why?


This RFC is an attempt to support scaling through a change in DFSDM topology.

These changes have some impacts on DFSDM and sd modulator bindings.
To keep things simple in this RFC, I skipped legacy support, to put the emphasis on the new bindings proposal.
There are two changes here: adoption of the generic IIO bindings and new "io-backends" property. This needs to be put in two separate patches at the end, I think (as already done for driver patches)

Anyway, the current bindings would become deprecated with these changes. I still have to consider how to support these legacy bindings for next step, However.

BRs
Olivier

- Add ADC generic channel binding and remove support of deprecated
channel bindings.

When was it deprecated?

- DFSDM is now implemented as a channel provider, so remove io-channels
properties.
- Add iio-backend property to connect DFSDM to an SD modulator.

io-backends

All sorts of ABI issues with this change. Please explain why you don't
care.


Signed-off-by: Olivier Moysan <olivier.moysan@xxxxxxxxxxx>
---
.../bindings/iio/adc/st,stm32-dfsdm-adc.yaml | 189 ++++++------------
1 file changed, 63 insertions(+), 126 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml b/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml
index 1970503389aa..128545cedc7f 100644
--- a/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml
@@ -85,22 +85,14 @@ patternProperties:
description: Specifies the DFSDM filter instance used.
maxItems: 1
- interrupts:
- maxItems: 1
+ '#address-cells':
+ const: 1
- st,adc-channels:
- description: |
- List of single-ended channels muxed for this ADC.
- On stm32h7 and stm32mp1:
- - For st,stm32-dfsdm-adc: up to 8 channels numbered from 0 to 7.
- - For st,stm32-dfsdm-dmic: 1 channel numbered from 0 to 7.
- $ref: /schemas/types.yaml#/definitions/uint32-array
- items:
- minimum: 0
- maximum: 7
+ '#size-cells':
+ const: 0
- st,adc-channel-names:
- description: List of single-ended channel names.
+ interrupts:
+ maxItems: 1
st,filter-order:
description: |
@@ -111,39 +103,6 @@ patternProperties:
$ref: /schemas/types.yaml#/definitions/uint32
maximum: 5
- "#io-channel-cells":
- const: 1
-
- st,adc-channel-types:
- description: |
- Single-ended channel input type.
- - "SPI_R": SPI with data on rising edge (default)
- - "SPI_F": SPI with data on falling edge
- - "MANCH_R": manchester codec, rising edge = logic 0, falling edge = logic 1
- - "MANCH_F": manchester codec, rising edge = logic 1, falling edge = logic 0
- items:
- enum: [ SPI_R, SPI_F, MANCH_R, MANCH_F ]
- $ref: /schemas/types.yaml#/definitions/non-unique-string-array
-
- st,adc-channel-clk-src:
- description: |
- Conversion clock source.
- - "CLKIN": external SPI clock (CLKIN x)
- - "CLKOUT": internal SPI clock (CLKOUT) (default)
- - "CLKOUT_F": internal SPI clock divided by 2 (falling edge).
- - "CLKOUT_R": internal SPI clock divided by 2 (rising edge).
- items:
- enum: [ CLKIN, CLKOUT, CLKOUT_F, CLKOUT_R ]
- $ref: /schemas/types.yaml#/definitions/non-unique-string-array
-
- st,adc-alt-channel:
- description:
- Must be defined if two sigma delta modulators are
- connected on same SPI input.
- If not set, channel n is connected to SPI input n.
- If set, channel n is connected to SPI input n + 1.
- type: boolean
-
st,filter0-sync:
description:
Set to 1 to synchronize with DFSDM filter instance 0.
@@ -157,14 +116,68 @@ patternProperties:
items:
- const: rx
+ patternProperties:
+ "^channel@([0-9]|1[0-9])$":
+ type: object
+ $ref: "adc.yaml"
+ description: Represents the external channels which are connected to the DFSDM.
+
+ properties:
+ reg:
+ items:
+ minimum: 0
+ maximum: 19
+
+ label:
+ description: |
+ Unique name to identify channel.
+
+ st,adc-channel-types:
+ description: |
+ Single-ended channel input type.
+ - "SPI_R": SPI with data on rising edge (default)
+ - "SPI_F": SPI with data on falling edge
+ - "MANCH_R": manchester codec, rising edge = logic 0, falling edge = logic 1
+ - "MANCH_F": manchester codec, rising edge = logic 1, falling edge = logic 0
+ items:
+ enum: [ SPI_R, SPI_F, MANCH_R, MANCH_F ]
+ $ref: /schemas/types.yaml#/definitions/non-unique-string-array
+
+ st,adc-channel-clk-src:
+ description: |
+ Conversion clock source.
+ - "CLKIN": external SPI clock (CLKIN x)
+ - "CLKOUT": internal SPI clock (CLKOUT) (default)
+ - "CLKOUT_F": internal SPI clock divided by 2 (falling edge).
+ - "CLKOUT_R": internal SPI clock divided by 2 (rising edge).
+ items:
+ enum: [ CLKIN, CLKOUT, CLKOUT_F, CLKOUT_R ]
+ $ref: /schemas/types.yaml#/definitions/non-unique-string-array
+
+ st,adc-alt-channel:
+ description:
+ Must be defined if two sigma delta modulators are
+ connected on same SPI input.
+ If not set, channel n is connected to SPI input n.
+ If set, channel n is connected to SPI input n + 1.
+ type: boolean
+
+ io-backends:
+ description: |
+ phandle to an external sigma delta modulator or internal ADC output.
+ $ref: /schemas/types.yaml#/definitions/phandle
+
+ required:
+ - reg
+ - io-backends
+
+ additionalProperties: false
+
required:
- compatible
- reg
- interrupts
- - st,adc-channels
- - st,adc-channel-names
- st,filter-order
- - "#io-channel-cells"
allOf:
- if:
@@ -175,14 +188,6 @@ patternProperties:
then:
properties:
- st,adc-channels:
- minItems: 1
- maxItems: 8
-
- st,adc-channel-names:
- minItems: 1
- maxItems: 8
-
st,adc-channel-types:
minItems: 1
maxItems: 8
@@ -191,14 +196,6 @@ patternProperties:
minItems: 1
maxItems: 8
- io-channels:
- description:
- From common IIO binding. Used to pipe external sigma delta
- modulator or internal ADC output to DFSDM channel.
-
- required:
- - io-channels
-
- if:
properties:
compatible:
@@ -207,12 +204,6 @@ patternProperties:
then:
properties:
- st,adc-channels:
- maxItems: 1
-
- st,adc-channel-names:
- maxItems: 1
-
st,adc-channel-types:
maxItems: 1
@@ -237,15 +228,9 @@ patternProperties:
"#sound-dai-cells":
const: 0
- io-channels:
- description:
- From common IIO binding. Used to pipe external sigma delta
- modulator or internal ADC output to DFSDM channel.
-
required:
- compatible
- "#sound-dai-cells"
- - io-channels
allOf:
- if:
@@ -278,52 +263,4 @@ allOf:
minimum: 0
maximum: 5
-examples:
- - |
- #include <dt-bindings/interrupt-controller/arm-gic.h>
- #include <dt-bindings/clock/stm32mp1-clks.h>
- dfsdm: dfsdm@4400d000 {
- compatible = "st,stm32mp1-dfsdm";
- reg = <0x4400d000 0x800>;
- clocks = <&rcc DFSDM_K>, <&rcc ADFSDM_K>;
- clock-names = "dfsdm", "audio";
- #address-cells = <1>;
- #size-cells = <0>;
-
- dfsdm0: filter@0 {
- compatible = "st,stm32-dfsdm-dmic";
- reg = <0>;
- interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
- dmas = <&dmamux1 101 0x400 0x01>;
- dma-names = "rx";
- #io-channel-cells = <1>;
- st,adc-channels = <1>;
- st,adc-channel-names = "dmic0";
- st,adc-channel-types = "SPI_R";
- st,adc-channel-clk-src = "CLKOUT";
- st,filter-order = <5>;
-
- asoc_pdm0: dfsdm-dai {
- compatible = "st,stm32h7-dfsdm-dai";
- #sound-dai-cells = <0>;
- io-channels = <&dfsdm0 0>;
- };
- };
-
- dfsdm_pdm1: filter@1 {
- compatible = "st,stm32-dfsdm-adc";
- reg = <1>;
- interrupts = <GIC_SPI 111 IRQ_TYPE_LEVEL_HIGH>;
- dmas = <&dmamux1 102 0x400 0x01>;
- dma-names = "rx";
- #io-channel-cells = <1>;
- st,adc-channels = <2 3>;
- st,adc-channel-names = "in2", "in3";
- st,adc-channel-types = "SPI_R", "SPI_R";
- st,adc-channel-clk-src = "CLKOUT_F", "CLKOUT_F";
- io-channels = <&sd_adc2 &sd_adc3>;
- st,filter-order = <1>;
- };
- };
-
...
--
2.25.1