5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Pratyush Yadav p.yadav@ti.com
[ Upstream commit 8762b07c95c18fbbe1c6b3eb1e8e686091c346b5 ]
Many SPI controllers need to add properties to peripheral devices. This could be the delay in clock or data lines, etc. These properties are controller specific but need to be defined in the peripheral node because they are per-peripheral and there can be multiple peripherals attached to a controller.
If these properties are not added to the peripheral binding, then the dtbs check emits a warning. But these properties do not make much sense in the peripheral binding because they are controller-specific and they will just pollute every peripheral binding. So this binding is added to collect all such properties from all such controllers. Peripheral bindings should simply refer to this binding and they should be rid of the warnings.
There are some limitations with this approach. Firstly, there is no way to specify required properties. The schema contains properties for all controllers and there is no way to know which controller is being used. Secondly, there is no way to restrict additional properties. Since this schema will be used with an allOf operator, additionalProperties needs to be true. In addition, the peripheral schema will have to set unevaluatedProperties: false.
Despite these limitations, this appears to be the best solution to this problem that doesn't involve modifying existing tools or schema specs.
Signed-off-by: Pratyush Yadav p.yadav@ti.com Reviewed-by: Rob Herring robh@kernel.org Link: https://lore.kernel.org/r/20211109181911.2251-2-p.yadav@ti.com Signed-off-by: Mark Brown broonie@kernel.org Stable-dep-of: 609bc99a4452 ("dt-bindings: leds: class-multicolor: Fix path to color definitions") Signed-off-by: Sasha Levin sashal@kernel.org --- .../bindings/spi/spi-controller.yaml | 69 +-------------- .../bindings/spi/spi-peripheral-props.yaml | 87 +++++++++++++++++++ 2 files changed, 89 insertions(+), 67 deletions(-) create mode 100644 Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml
diff --git a/Documentation/devicetree/bindings/spi/spi-controller.yaml b/Documentation/devicetree/bindings/spi/spi-controller.yaml index 8246891602e77..36b72518f5654 100644 --- a/Documentation/devicetree/bindings/spi/spi-controller.yaml +++ b/Documentation/devicetree/bindings/spi/spi-controller.yaml @@ -94,73 +94,8 @@ patternProperties: "^.*@[0-9a-f]+$": type: object
- properties: - compatible: - description: - Compatible of the SPI device. - - reg: - minItems: 1 - maxItems: 256 - items: - minimum: 0 - maximum: 256 - description: - Chip select used by the device. - - spi-3wire: - $ref: /schemas/types.yaml#/definitions/flag - description: - The device requires 3-wire mode. - - spi-cpha: - $ref: /schemas/types.yaml#/definitions/flag - description: - The device requires shifted clock phase (CPHA) mode. - - spi-cpol: - $ref: /schemas/types.yaml#/definitions/flag - description: - The device requires inverse clock polarity (CPOL) mode. - - spi-cs-high: - $ref: /schemas/types.yaml#/definitions/flag - description: - The device requires the chip select active high. - - spi-lsb-first: - $ref: /schemas/types.yaml#/definitions/flag - description: - The device requires the LSB first mode. - - spi-max-frequency: - $ref: /schemas/types.yaml#/definitions/uint32 - description: - Maximum SPI clocking speed of the device in Hz. - - spi-rx-bus-width: - description: - Bus width to the SPI bus used for read transfers. - If 0 is provided, then no RX will be possible on this device. - $ref: /schemas/types.yaml#/definitions/uint32 - enum: [0, 1, 2, 4, 8] - default: 1 - - spi-rx-delay-us: - description: - Delay, in microseconds, after a read transfer. - - spi-tx-bus-width: - description: - Bus width to the SPI bus used for write transfers. - If 0 is provided, then no TX will be possible on this device. - $ref: /schemas/types.yaml#/definitions/uint32 - enum: [0, 1, 2, 4, 8] - default: 1 - - spi-tx-delay-us: - description: - Delay, in microseconds, after a write transfer. + allOf: + - $ref: spi-peripheral-props.yaml
required: - compatible diff --git a/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml b/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml new file mode 100644 index 0000000000000..105fa2840e72a --- /dev/null +++ b/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml @@ -0,0 +1,87 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/spi/spi-peripheral-props.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Peripheral-specific properties for a SPI bus. + +description: + Many SPI controllers need to add properties to peripheral devices. They could + be common properties like spi-max-frequency, spi-cpha, etc. or they could be + controller specific like delay in clock or data lines, etc. These properties + need to be defined in the peripheral node because they are per-peripheral and + there can be multiple peripherals attached to a controller. All those + properties are listed here. The controller specific properties should go in + their own separate schema that should be referenced from here. + +maintainers: + - Pratyush Yadav p.yadav@ti.com + +properties: + reg: + minItems: 1 + maxItems: 256 + items: + minimum: 0 + maximum: 256 + description: + Chip select used by the device. + + spi-3wire: + $ref: /schemas/types.yaml#/definitions/flag + description: + The device requires 3-wire mode. + + spi-cpha: + $ref: /schemas/types.yaml#/definitions/flag + description: + The device requires shifted clock phase (CPHA) mode. + + spi-cpol: + $ref: /schemas/types.yaml#/definitions/flag + description: + The device requires inverse clock polarity (CPOL) mode. + + spi-cs-high: + $ref: /schemas/types.yaml#/definitions/flag + description: + The device requires the chip select active high. + + spi-lsb-first: + $ref: /schemas/types.yaml#/definitions/flag + description: + The device requires the LSB first mode. + + spi-max-frequency: + $ref: /schemas/types.yaml#/definitions/uint32 + description: + Maximum SPI clocking speed of the device in Hz. + + spi-rx-bus-width: + description: + Bus width to the SPI bus used for read transfers. + If 0 is provided, then no RX will be possible on this device. + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [0, 1, 2, 4, 8] + default: 1 + + spi-rx-delay-us: + description: + Delay, in microseconds, after a read transfer. + + spi-tx-bus-width: + description: + Bus width to the SPI bus used for write transfers. + If 0 is provided, then no TX will be possible on this device. + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [0, 1, 2, 4, 8] + default: 1 + + spi-tx-delay-us: + description: + Delay, in microseconds, after a write transfer. + +# The controller specific properties go here. + +additionalProperties: true