[PATCH v2 0/8] iio: adc: dfsdm: add scaling support
The aim of this serie is to add scaling support to STM32 DFSDM peripheral in the analog context.
The DFSDM currently operates as a consumer of IIO channels provided by a generic SD modulator. As previously discussed in RFC [1], this topology is not suitable for implementing scaling.
This series brings the integration of the DFSDM driver with the new IIO backend framework [2], enabling the DFSDM IIO device to offer scaling feature based on reference voltage data obtained from the IIO SD modulator backend. This generic SD modulator backend takes the place of the former SD modulator, used with legacy implementation.
The DFSDM driver has been updated to adopt the generic ADC channel binding [3]. The reasons for this include: - Reducing the use of proprietary properties - Simplifying the coexistence of legacy and new backend bindings - Prepare the support of the MDF peripheral on STM32MP25 SoC
Backward compatibility is maintained through legacy support.
This series extends the backend framework with the following APIs: - iio_backend_read_raw: This API is intented to retrieve the voltage information from the backend. It is based on IIO framework read_raw API. - iio_backend_disable / iio_backend_enable: backend enable/disable to be used for PM management - devm_iio_backend_fwnode_get Intended for parsing DT subnodes to allow generic channel binding support, as generic channel DT nodes are not populated as devices.
[1]: https://lore.kernel.org/lkml/20200204101008.11411-1-olivier.moysan@st.com/ [2]: https://lore.kernel.org/all/20240206-iio-backend-v9-0-df66d159c000@analog.co... [3]: devicetree/bindings/iio/adc/adc.yaml
Changes in v2: - Update enable/disable backend API - Rename devm_iio_backend_subnode_get(), as devm_iio_backend_fwnode_get() - Update iio_backend_read_raw() prototype to fully match IIO framework read_raw callback prototype. - Change st,adc-channel-type property name and type in DFSDM binding - Remove sd-backend and rename ads1201 compatibles in SD binding
Conor, in this v2, I left the SD modulator driver & binding unchanged, regarding the naming issue you raised previously.
The problem here is that we have two versions of the generic sigma delta modulator driver: one for legacy support and a new one to support new binding. Maybe an alternate, is to rename former sd modulator as "legacy" or something similar. I will address this point in a v3 if necessary.
Olivier Moysan (8): iio: add read raw service to iio backend framework iio: add enable and disable services to iio backend framework iio: add child nodes support in iio backend framework dt-bindings: iio: dfsdm: move to backend framework dt-bindings: iio: add sigma delta modulator backend iio: adc: stm32-dfsdm: adopt generic channels bindings iio: add sd modulator generic iio backend iio: adc: stm32-dfsdm: add scaling support to dfsdm
.../iio/adc/sd-modulator-backend.yaml | 39 +++ .../bindings/iio/adc/st,stm32-dfsdm-adc.yaml | 157 ++++++++- drivers/iio/adc/Kconfig | 11 + drivers/iio/adc/Makefile | 1 + drivers/iio/adc/sd_adc_backend.c | 117 +++++++ drivers/iio/adc/stm32-dfsdm-adc.c | 302 +++++++++++++++--- drivers/iio/industrialio-backend.c | 108 +++++-- include/linux/iio/backend.h | 10 +- 8 files changed, 679 insertions(+), 66 deletions(-) create mode 100644 Documentation/devicetree/bindings/iio/adc/sd-modulator-backend.yaml create mode 100644 drivers/iio/adc/sd_adc_backend.c
base-commit: 2dfa1b7bfc07e58acb9f9eaa8c871f37189dbfee
Change the DFSDM binding to use the new IIO backend framework, along with the adoption of IIO generic channels. This binding change allows to add scaling support to the DFSDM.
Keep the legacy binding as deprecated for backward compatibility.
The io-backends property is supported only in generic IIO channel binding.
- Channel description with the generic binding (Audio and Analog):
Properties superseded by generic properties: st,adc-channels: becomes "reg" property in channel node st,adc-channel-names: becomes "label" property in channel node Properties moved to channel child node: st,adc-channel-types: becomes st,adc-channel-type st,adc-channel-clk-src, st,adc-alt-channel
- Analog binding:
DFSDM filter channel is configured as an IIO backend consumer. Add io-backends property in channel child nodes.
DFSDM is no more configured as a channel consumer from SD modulator. Use of io-channels in DFSDM node is deprecated.
- Audio binding:
DFSDM audio DAI is configured as a channel consumer from DFSDM filter. No change compare to legacy.
Signed-off-by: Olivier Moysan olivier.moysan@foss.st.com --- .../bindings/iio/adc/st,stm32-dfsdm-adc.yaml | 157 +++++++++++++++++- 1 file changed, 151 insertions(+), 6 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 c1b1324fa132..1802120b16b0 100644 --- a/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml +++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml @@ -102,9 +102,11 @@ patternProperties: items: minimum: 0 maximum: 7 + deprecated: true
st,adc-channel-names: description: List of single-ended channel names. + deprecated: true
st,filter-order: description: | @@ -118,6 +120,12 @@ patternProperties: "#io-channel-cells": const: 1
+ '#address-cells': + const: 1 + + '#size-cells': + const: 0 + st,adc-channel-types: description: | Single-ended channel input type. @@ -128,6 +136,7 @@ patternProperties: items: enum: [ SPI_R, SPI_F, MANCH_R, MANCH_F ] $ref: /schemas/types.yaml#/definitions/non-unique-string-array + deprecated: true
st,adc-channel-clk-src: description: | @@ -139,6 +148,7 @@ patternProperties: items: enum: [ CLKIN, CLKOUT, CLKOUT_F, CLKOUT_R ] $ref: /schemas/types.yaml#/definitions/non-unique-string-array + deprecated: true
st,adc-alt-channel: description: @@ -147,6 +157,7 @@ patternProperties: If not set, channel n is connected to SPI input n. If set, channel n is connected to SPI input n + 1. type: boolean + deprecated: true
st,filter0-sync: description: @@ -165,11 +176,64 @@ patternProperties: - compatible - reg - interrupts - - st,adc-channels - - st,adc-channel-names - st,filter-order - "#io-channel-cells"
+ patternProperties: + "^channel@([0-9]|1[0-9])$": + type: object + $ref: adc.yaml + description: Represents the external channels which are connected to the DFSDM. + + properties: + reg: + items: + minimum: 0 + maximum: 8 + + label: + description: + Unique name to identify which channel this is. + + st,adc-channel-type: + 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/string + + 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 ] + $ref: /schemas/types.yaml#/definitions/string + + st,adc-alt-channel: + description: + Must be defined if two sigma delta modulators are + connected on same SPI input. + If not set, channel n is connected to SPI input n. + If set, channel n is connected to SPI input n + 1. + type: boolean + + io-backends: + description: + Used to pipe external sigma delta modulator or internal ADC backend to DFSDM channel. + + required: + - reg + + additionalProperties: false + allOf: - if: properties: @@ -199,9 +263,19 @@ patternProperties: description: From common IIO binding. Used to pipe external sigma delta modulator or internal ADC output to DFSDM channel. + deprecated: true
- required: - - io-channels + if: + required: + - st,adc-channels + then: + required: + - io-channels + + patternProperties: + "^channel@([0-9]|1[0-9])$": + required: + - io-backends
- if: properties: @@ -294,7 +368,77 @@ examples: #address-cells = <1>; #size-cells = <0>;
+ // Example 1: Audio use case with generic binding 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>; + #address-cells = <1>; + #size-cells = <0>; + st,filter-order = <5>; + + channel@1 { + reg = <1>; + label = "dmic0"; + st,adc-channel-type = "SPI_R"; + st,adc-channel-clk-src = "CLKOUT"; + st,adc-alt-channel; + }; + + asoc_pdm0: dfsdm-dai { + compatible = "st,stm32h7-dfsdm-dai"; + #sound-dai-cells = <0>; + io-channels = <&dfsdm0 0>; + }; + }; + + // Example 1: Analog use case with generic binding + dfsdm1: 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"; + st,filter-order = <1>; + #io-channel-cells = <1>; + #address-cells = <1>; + #size-cells = <0>; + + channel@2 { + reg = <2>; + label = "in2"; + st,adc-channel-type = "SPI_F"; + st,adc-channel-clk-src = "CLKOUT"; + st,adc-alt-channel; + io-backends = <&sd_adc2>; + }; + + channel@3 { + reg = <3>; + label = "in3"; + st,adc-channel-type = "SPI_R"; + st,adc-channel-clk-src = "CLKOUT"; + io-backends = <&sd_adc3>; + }; + }; + }; + + - | + #include <dt-bindings/interrupt-controller/arm-gic.h> + #include <dt-bindings/clock/stm32mp1-clks.h> + dfsdm_2: 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>; + + // Example 3: Audio use case with legacy binding + dfsdm0_2: filter@0 { compatible = "st,stm32-dfsdm-dmic"; reg = <0>; interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>; @@ -307,14 +451,15 @@ examples: st,adc-channel-clk-src = "CLKOUT"; st,filter-order = <5>;
- asoc_pdm0: dfsdm-dai { + asoc_pdm0_2: dfsdm-dai { compatible = "st,stm32h7-dfsdm-dai"; #sound-dai-cells = <0>; io-channels = <&dfsdm0 0>; }; };
- dfsdm_pdm1: filter@1 { + // Example 3: Analog use case with legacy binding + dfsdm1_2: filter@1 { compatible = "st,stm32-dfsdm-adc"; reg = <1>; interrupts = <GIC_SPI 111 IRQ_TYPE_LEVEL_HIGH>;
On Tue, Jun 25, 2024 at 05:07:12PM +0200, Olivier Moysan wrote:
Change the DFSDM binding to use the new IIO backend framework, along with the adoption of IIO generic channels. This binding change allows to add scaling support to the DFSDM.
Keep the legacy binding as deprecated for backward compatibility.
The io-backends property is supported only in generic IIO channel binding.
Channel description with the generic binding (Audio and Analog):
Properties superseded by generic properties: st,adc-channels: becomes "reg" property in channel node st,adc-channel-names: becomes "label" property in channel node Properties moved to channel child node: st,adc-channel-types: becomes st,adc-channel-type st,adc-channel-clk-src, st,adc-alt-channel
Analog binding:
DFSDM filter channel is configured as an IIO backend consumer. Add io-backends property in channel child nodes.
DFSDM is no more configured as a channel consumer from SD modulator. Use of io-channels in DFSDM node is deprecated.
Audio binding:
DFSDM audio DAI is configured as a channel consumer from DFSDM filter. No change compare to legacy.
Signed-off-by: Olivier Moysan olivier.moysan@foss.st.com
.../bindings/iio/adc/st,stm32-dfsdm-adc.yaml | 157 +++++++++++++++++- 1 file changed, 151 insertions(+), 6 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 c1b1324fa132..1802120b16b0 100644 --- a/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml +++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml @@ -102,9 +102,11 @@ patternProperties: items: minimum: 0 maximum: 7
deprecated: true st,adc-channel-names: description: List of single-ended channel names.deprecated: true st,filter-order: description: |@@ -118,6 +120,12 @@ patternProperties: "#io-channel-cells": const: 1
'#address-cells':const: 1'#size-cells':const: 0st,adc-channel-types: description: | Single-ended channel input type.@@ -128,6 +136,7 @@ patternProperties: items: enum: [ SPI_R, SPI_F, MANCH_R, MANCH_F ] $ref: /schemas/types.yaml#/definitions/non-unique-string-array
deprecated: true st,adc-channel-clk-src: description: |@@ -139,6 +148,7 @@ patternProperties: items: enum: [ CLKIN, CLKOUT, CLKOUT_F, CLKOUT_R ] $ref: /schemas/types.yaml#/definitions/non-unique-string-array
deprecated: true st,adc-alt-channel: description:@@ -147,6 +157,7 @@ patternProperties: If not set, channel n is connected to SPI input n. If set, channel n is connected to SPI input n + 1. type: boolean
deprecated: true st,filter0-sync: description:@@ -165,11 +176,64 @@ patternProperties: - compatible - reg - interrupts
- st,adc-channels- st,adc-channel-names - st,filter-order - "#io-channel-cells"
- patternProperties:
"^channel@([0-9]|1[0-9])$":
Unit-addresses are normally hex. And according to reg below, the max value is 8.
type: object$ref: adc.yamldescription: Represents the external channels which are connected to the DFSDM.properties:reg:items:minimum: 0maximum: 8
More than 1 reg entry valid? Either way, you need maxItems. Or you can just drop 'items'
label:description:Unique name to identify which channel this is.st,adc-channel-type:description: |Single-ended channel input type.- "SPI_R": SPI with data on rising edge (default)- "SPI_F": SPI with data on falling edge- "MANCH_R": manchester codec, rising edge = logic 0, falling edge = logic 1- "MANCH_F": manchester codec, rising edge = logic 1, falling edge = logic 0items:
'items' is for arrays, but...
enum: [ SPI_R, SPI_F, MANCH_R, MANCH_F ]$ref: /schemas/types.yaml#/definitions/string
not an 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:
ditto
enum: [ CLKIN, CLKOUT, CLKOUT_F, CLKOUT_R ]$ref: /schemas/types.yaml#/definitions/stringst,adc-alt-channel:description:Must be defined if two sigma delta modulators areconnected 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: booleanio-backends:description:Used to pipe external sigma delta modulator or internal ADC backend to DFSDM channel.
How many entries (maxItems)?
required:- regadditionalProperties: false
Put this next to the $ref for the node. And switch to unevaluatedProperties and drop 'label' from here.
- allOf: - if: properties:
@@ -199,9 +263,19 @@ patternProperties: description: From common IIO binding. Used to pipe external sigma delta modulator or internal ADC output to DFSDM channel.
deprecated: true
required:- io-channels
if:required:- st,adc-channelsthen:required:- io-channelspatternProperties:"^channel@([0-9]|1[0-9])$":required:- io-backends
Don't think this is needed here. If channel node is present, the io-backends should always be required, right? Then this can go under the node schema.
Rob
Hi Rob,
On 6/28/24 23:35, Rob Herring wrote:
On Tue, Jun 25, 2024 at 05:07:12PM +0200, Olivier Moysan wrote:
Change the DFSDM binding to use the new IIO backend framework, along with the adoption of IIO generic channels. This binding change allows to add scaling support to the DFSDM.
Keep the legacy binding as deprecated for backward compatibility.
The io-backends property is supported only in generic IIO channel binding.
Channel description with the generic binding (Audio and Analog):
Properties superseded by generic properties: st,adc-channels: becomes "reg" property in channel node st,adc-channel-names: becomes "label" property in channel node Properties moved to channel child node: st,adc-channel-types: becomes st,adc-channel-type st,adc-channel-clk-src, st,adc-alt-channel
Analog binding:
DFSDM filter channel is configured as an IIO backend consumer. Add io-backends property in channel child nodes.
DFSDM is no more configured as a channel consumer from SD modulator. Use of io-channels in DFSDM node is deprecated.
Audio binding:
DFSDM audio DAI is configured as a channel consumer from DFSDM filter. No change compare to legacy.
Signed-off-by: Olivier Moysan olivier.moysan@foss.st.com
.../bindings/iio/adc/st,stm32-dfsdm-adc.yaml | 157 +++++++++++++++++- 1 file changed, 151 insertions(+), 6 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 c1b1324fa132..1802120b16b0 100644 --- a/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml +++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml @@ -102,9 +102,11 @@ patternProperties: items: minimum: 0 maximum: 7
deprecated: true st,adc-channel-names: description: List of single-ended channel names.deprecated: true st,filter-order: description: |@@ -118,6 +120,12 @@ patternProperties: "#io-channel-cells": const: 1
'#address-cells':const: 1'#size-cells':const: 0st,adc-channel-types: description: | Single-ended channel input type.@@ -128,6 +136,7 @@ patternProperties: items: enum: [ SPI_R, SPI_F, MANCH_R, MANCH_F ] $ref: /schemas/types.yaml#/definitions/non-unique-string-array
deprecated: true st,adc-channel-clk-src: description: |@@ -139,6 +148,7 @@ patternProperties: items: enum: [ CLKIN, CLKOUT, CLKOUT_F, CLKOUT_R ] $ref: /schemas/types.yaml#/definitions/non-unique-string-array
deprecated: true st,adc-alt-channel: description:@@ -147,6 +157,7 @@ patternProperties: If not set, channel n is connected to SPI input n. If set, channel n is connected to SPI input n + 1. type: boolean
deprecated: true st,filter0-sync: description:@@ -165,11 +176,64 @@ patternProperties: - compatible - reg - interrupts
- st,adc-channels- st,adc-channel-names - st,filter-order - "#io-channel-cells"
- patternProperties:
"^channel@([0-9]|1[0-9])$":Unit-addresses are normally hex. And according to reg below, the max value is 8.
Right. The maximum number of serial interfaces is 8. So, the pattern can be reduced to "^channel@([0-7])$":
type: object$ref: adc.yamldescription: Represents the external channels which are connected to the DFSDM.properties:reg:items:minimum: 0maximum: 8More than 1 reg entry valid? Either way, you need maxItems. Or you can just drop 'items'
Added "maxItems: 1" and dropped items.
label:description:Unique name to identify which channel this is.st,adc-channel-type: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 0items:'items' is for arrays, but...
Removed items
enum: [ SPI_R, SPI_F, MANCH_R, MANCH_F ]$ref: /schemas/types.yaml#/definitions/stringnot an array.
st,adc-channel-clk-src:description: |Conversion clock source.- "CLKIN": external SPI clock (CLKIN x)- "CLKOUT": internal SPI clock (CLKOUT) (default)- "CLKOUT_F": internal SPI clock divided by 2 (falling edge).- "CLKOUT_R": internal SPI clock divided by 2 (rising edge).items:ditto
Done
enum: [ CLKIN, CLKOUT, CLKOUT_F, CLKOUT_R ]$ref: /schemas/types.yaml#/definitions/stringst,adc-alt-channel:description:Must be defined if two sigma delta modulators areconnected 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: booleanio-backends:description:Used to pipe external sigma delta modulator or internal ADC backend to DFSDM channel.How many entries (maxItems)?
required:- regadditionalProperties: falsePut this next to the $ref for the node. And switch to unevaluatedProperties and drop 'label' from here.
Done
allOf: - if: properties:@@ -199,9 +263,19 @@ patternProperties: description: From common IIO binding. Used to pipe external sigma delta modulator or internal ADC output to DFSDM channel.
deprecated: true
required:- io-channels
if:required:- st,adc-channelsthen:required:- io-channelspatternProperties:"^channel@([0-9]|1[0-9])$":required:- io-backendsDon't think this is needed here. If channel node is present, the io-backends should always be required, right? Then this can go under the node schema.
The io-backends property is required only when we use st,stm32-dfsdm-adc compatible. In other words, when we are in an analog use case. In this case the channel is a consumer of a backend (typically a sd modulator) In an audio use case (compatible st,stm32-dfsdm-dmic) the backend is not required.
BRs Olivier
Rob
participants (2)
-
Olivier Moysan -
Rob Herring