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| -rw-r--r-- | Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml | 107 |
1 files changed, 107 insertions, 0 deletions
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 000000000..dca677f9e --- /dev/null +++ b/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml @@ -0,0 +1,107 @@ +# 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: + - Mark Brown <broonie@kernel.org> + +properties: + reg: + minItems: 1 + maxItems: 256 + items: + items: + - minimum: 0 + maximum: 256 + description: + Chip select used by the device. + + 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. + + rx-sample-delay-ns: + description: SPI Rx sample delay offset, unit is nanoseconds. + The delay from the default sample time before the actual + sample of the rxd input signal occurs. + + 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. + + stacked-memories: + description: Several SPI memories can be wired in stacked mode. + This basically means that either a device features several chip + selects, or that different devices must be seen as a single + bigger chip. This basically doubles (or more) the total address + space with only a single additional wire, while still needing + to repeat the commands when crossing a chip boundary. The size of + each chip should be provided as members of the array. + $ref: /schemas/types.yaml#/definitions/uint64-array + minItems: 2 + maxItems: 4 + + parallel-memories: + description: Several SPI memories can be wired in parallel mode. + The devices are physically on a different buses but will always + act synchronously as each data word is spread across the + different memories (eg. even bits are stored in one memory, odd + bits in the other). This basically doubles the address space and + the throughput while greatly complexifying the wiring because as + many busses as devices must be wired. The size of each chip should + be provided as members of the array. + $ref: /schemas/types.yaml#/definitions/uint64-array + minItems: 2 + maxItems: 4 + +# The controller specific properties go here. +allOf: + - $ref: cdns,qspi-nor-peripheral-props.yaml# + - $ref: samsung,spi-peripheral-props.yaml# + - $ref: nvidia,tegra210-quad-peripheral-props.yaml# + +additionalProperties: true |