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 7 title: Peripheral-specific properties for a SPI bus. 8 9 description: 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 18 maintainers: 19 - Mark Brown <broonie@kernel.org> 20 21 properties: 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-cs-setup-delay-ns: 48 description: 49 Delay in nanoseconds to be introduced by the controller after CS is 50 asserted. 51 52 spi-cs-hold-delay-ns: 53 description: 54 Delay in nanoseconds to be introduced by the controller before CS is 55 de-asserted. 56 57 spi-cs-inactive-delay-ns: 58 description: 59 Delay in nanoseconds to be introduced by the controller after CS is 60 de-asserted. 61 62 spi-rx-bus-width: 63 description: 64 Bus width to the SPI bus used for read transfers. 65 If 0 is provided, then no RX will be possible on this device. 66 $ref: /schemas/types.yaml#/definitions/uint32 67 enum: [0, 1, 2, 4, 8] 68 default: 1 69 70 spi-rx-delay-us: 71 description: 72 Delay, in microseconds, after a read transfer. 73 74 rx-sample-delay-ns: 75 description: SPI Rx sample delay offset, unit is nanoseconds. 76 The delay from the default sample time before the actual 77 sample of the rxd input signal occurs. 78 79 spi-tx-bus-width: 80 description: 81 Bus width to the SPI bus used for write transfers. 82 If 0 is provided, then no TX will be possible on this device. 83 $ref: /schemas/types.yaml#/definitions/uint32 84 enum: [0, 1, 2, 4, 8] 85 default: 1 86 87 spi-tx-delay-us: 88 description: 89 Delay, in microseconds, after a write transfer. 90 91 stacked-memories: 92 description: Several SPI memories can be wired in stacked mode. 93 This basically means that either a device features several chip 94 selects, or that different devices must be seen as a single 95 bigger chip. This basically doubles (or more) the total address 96 space with only a single additional wire, while still needing 97 to repeat the commands when crossing a chip boundary. The size of 98 each chip should be provided as members of the array. 99 $ref: /schemas/types.yaml#/definitions/uint64-array 100 minItems: 2 101 maxItems: 4 102 103 parallel-memories: 104 description: Several SPI memories can be wired in parallel mode. 105 The devices are physically on a different buses but will always 106 act synchronously as each data word is spread across the 107 different memories (eg. even bits are stored in one memory, odd 108 bits in the other). This basically doubles the address space and 109 the throughput while greatly complexifying the wiring because as 110 many busses as devices must be wired. The size of each chip should 111 be provided as members of the array. 112 $ref: /schemas/types.yaml#/definitions/uint64-array 113 minItems: 2 114 maxItems: 4 115 116 st,spi-midi-ns: 117 description: | 118 Only for STM32H7, (Master Inter-Data Idleness) minimum time 119 delay in nanoseconds inserted between two consecutive data frames. 120 121 # The controller specific properties go here. 122 allOf: 123 - $ref: arm,pl022-peripheral-props.yaml# 124 - $ref: cdns,qspi-nor-peripheral-props.yaml# 125 - $ref: fsl,dspi-peripheral-props.yaml# 126 - $ref: samsung,spi-peripheral-props.yaml# 127 - $ref: nvidia,tegra210-quad-peripheral-props.yaml# 128 129 additionalProperties: true
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