1# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) 2%YAML 1.2 3--- 4$id: http://devicetree.org/schemas/spi/spi-peripheral-props.yaml# 5$schema: http://devicetree.org/meta-schemas/core.yaml# 6 7title: Peripheral-specific properties for a SPI bus. 8 9description: 10 Many SPI controllers need to add properties to peripheral devices. They could 11 be common properties like spi-max-frequency, spi-cpha, etc. or they could be 12 controller specific like delay in clock or data lines, etc. These properties 13 need to be defined in the peripheral node because they are per-peripheral and 14 there can be multiple peripherals attached to a controller. All those 15 properties are listed here. The controller specific properties should go in 16 their own separate schema that should be referenced from here. 17 18maintainers: 19 - Mark Brown <broonie@kernel.org> 20 21properties: 22 reg: 23 minItems: 1 24 maxItems: 256 25 items: 26 items: 27 - minimum: 0 28 maximum: 256 29 description: 30 Chip select used by the device. 31 32 spi-cs-high: 33 $ref: /schemas/types.yaml#/definitions/flag 34 description: 35 The device requires the chip select active high. 36 37 spi-lsb-first: 38 $ref: /schemas/types.yaml#/definitions/flag 39 description: 40 The device requires the LSB first mode. 41 42 spi-max-frequency: 43 $ref: /schemas/types.yaml#/definitions/uint32 44 description: 45 Maximum SPI clocking speed of the device in Hz. 46 47 spi-rx-bus-width: 48 description: 49 Bus width to the SPI bus used for read transfers. 50 If 0 is provided, then no RX will be possible on this device. 51 $ref: /schemas/types.yaml#/definitions/uint32 52 enum: [0, 1, 2, 4, 8] 53 default: 1 54 55 spi-rx-delay-us: 56 description: 57 Delay, in microseconds, after a read transfer. 58 59 rx-sample-delay-ns: 60 description: SPI Rx sample delay offset, unit is nanoseconds. 61 The delay from the default sample time before the actual 62 sample of the rxd input signal occurs. 63 64 spi-tx-bus-width: 65 description: 66 Bus width to the SPI bus used for write transfers. 67 If 0 is provided, then no TX will be possible on this device. 68 $ref: /schemas/types.yaml#/definitions/uint32 69 enum: [0, 1, 2, 4, 8] 70 default: 1 71 72 spi-tx-delay-us: 73 description: 74 Delay, in microseconds, after a write transfer. 75 76 stacked-memories: 77 description: Several SPI memories can be wired in stacked mode. 78 This basically means that either a device features several chip 79 selects, or that different devices must be seen as a single 80 bigger chip. This basically doubles (or more) the total address 81 space with only a single additional wire, while still needing 82 to repeat the commands when crossing a chip boundary. The size of 83 each chip should be provided as members of the array. 84 $ref: /schemas/types.yaml#/definitions/uint64-array 85 minItems: 2 86 maxItems: 4 87 88 parallel-memories: 89 description: Several SPI memories can be wired in parallel mode. 90 The devices are physically on a different buses but will always 91 act synchronously as each data word is spread across the 92 different memories (eg. even bits are stored in one memory, odd 93 bits in the other). This basically doubles the address space and 94 the throughput while greatly complexifying the wiring because as 95 many busses as devices must be wired. The size of each chip should 96 be provided as members of the array. 97 $ref: /schemas/types.yaml#/definitions/uint64-array 98 minItems: 2 99 maxItems: 4 100 101# The controller specific properties go here. 102allOf: 103 - $ref: cdns,qspi-nor-peripheral-props.yaml# 104 - $ref: samsung,spi-peripheral-props.yaml# 105 - $ref: nvidia,tegra210-quad-peripheral-props.yaml# 106 107additionalProperties: true 108