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