linux/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml

# 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-cs-high, 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-cs-setup-delay-ns:
    description:
      Delay in nanoseconds to be introduced by the controller after CS is
      asserted.

  spi-cs-hold-delay-ns:
    description:
      Delay in nanoseconds to be introduced by the controller before CS is
      de-asserted.

  spi-cs-inactive-delay-ns:
    description:
      Delay in nanoseconds to be introduced by the controller after CS is
      de-asserted.

  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.

      Some SPI peripherals and controllers may have multiple data lanes for
      receiving two or more words at the same time. If this is the case, each
      index in the array represents the lane on both the SPI peripheral and
      controller. Additional mapping properties may be needed if a lane is
      skipped on either side.
    $ref: /schemas/types.yaml#/definitions/uint32-array
    items:
      enum: [0, 1, 2, 4, 8]
    default: [1]

  spi-rx-lane-map:
    description: Mapping of peripheral SDO lanes to controller SDI lanes.
      Each index in the array represents a peripheral SDO lane, and the value
      at that index represents the corresponding controller SDI lane.
    $ref: /schemas/types.yaml#/definitions/uint32-array
    default: [0, 1, 2, 3, 4, 5, 6, 7]

  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.

      Some SPI peripherals and controllers may have multiple data lanes for
      transmitting two or more words at the same time. If this is the case, each
      index in the array represents the lane on both the SPI peripheral and
      controller. Additional mapping properties may be needed if a lane is
      skipped on either side.
    $ref: /schemas/types.yaml#/definitions/uint32-array
    items:
      enum: [0, 1, 2, 4, 8]
    default: [1]

  spi-tx-lane-map:
    description: Mapping of peripheral SDI lanes to controller SDO lanes.
      Each index in the array represents a peripheral SDI lane, and the value
      at that index represents the corresponding controller SDO lane.
    $ref: /schemas/types.yaml#/definitions/uint32-array
    default: [0, 1, 2, 3, 4, 5, 6, 7]

  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

  st,spi-midi-ns:
    deprecated: true
    description: |
      Only for STM32H7, (Master Inter-Data Idleness) minimum time
      delay in nanoseconds inserted between two consecutive data frames.

# The controller specific properties go here.
allOf:
  - $ref: arm,pl022-peripheral-props.yaml#
  - $ref: cdns,qspi-nor-peripheral-props.yaml#
  - $ref: fsl,dspi-peripheral-props.yaml#
  - $ref: samsung,spi-peripheral-props.yaml#
  - $ref: nvidia,tegra210-quad-peripheral-props.yaml#

additionalProperties: true