diff options
Diffstat (limited to 'Documentation/devicetree/bindings/spi/spi-controller.yaml')
| -rw-r--r-- | Documentation/devicetree/bindings/spi/spi-controller.yaml | 188 |
1 files changed, 120 insertions, 68 deletions
diff --git a/Documentation/devicetree/bindings/spi/spi-controller.yaml b/Documentation/devicetree/bindings/spi/spi-controller.yaml index c6a2f543648b..82d051f7bd6e 100644 --- a/Documentation/devicetree/bindings/spi/spi-controller.yaml +++ b/Documentation/devicetree/bindings/spi/spi-controller.yaml @@ -4,7 +4,7 @@ $id: http://devicetree.org/schemas/spi/spi-controller.yaml# $schema: http://devicetree.org/meta-schemas/core.yaml# -title: SPI Controller Generic Binding +title: SPI Controller Common Properties maintainers: - Mark Brown <broonie@kernel.org> @@ -17,10 +17,10 @@ description: | properties: $nodename: - pattern: "^spi(@.*|-[0-9a-f])*$" + pattern: "^spi(@.*|-([0-9]|[1-9][0-9]+))?$" "#address-cells": - const: 1 + enum: [0, 1] "#size-cells": const: 0 @@ -42,6 +42,53 @@ properties: cs2 : &gpio1 1 0 cs3 : &gpio1 2 0 + The second flag of a gpio descriptor can be GPIO_ACTIVE_HIGH (0) + or GPIO_ACTIVE_LOW(1). Legacy device trees often use 0. + + There is a special rule set for combining the second flag of an + cs-gpio with the optional spi-cs-high flag for SPI slaves. + + Each table entry defines how the CS pin is to be physically + driven (not considering potential gpio inversions by pinmux): + + device node | cs-gpio | CS pin state active | Note + ================+===============+=====================+===== + spi-cs-high | - | H | + - | - | L | + spi-cs-high | ACTIVE_HIGH | H | + - | ACTIVE_HIGH | L | 1 + spi-cs-high | ACTIVE_LOW | H | 2 + - | ACTIVE_LOW | L | + + Notes: + 1) Should print a warning about polarity inversion. + Here it would be wise to avoid and define the gpio as + ACTIVE_LOW. + 2) Should print a warning about polarity inversion + because ACTIVE_LOW is overridden by spi-cs-high. + Should be generally avoided and be replaced by + spi-cs-high + ACTIVE_HIGH. + + The simplest way to obtain an active-high CS signal is to configure the + controller's cs-gpio property with the ACTIVE_HIGH flag and set the + peripheral's spi-cs-high property. See example below for a better + understanding. + + fifo-depth: + $ref: /schemas/types.yaml#/definitions/uint32 + description: + Size of the RX and TX data FIFOs in bytes. + + rx-fifo-depth: + $ref: /schemas/types.yaml#/definitions/uint32 + description: + Size of the RX data FIFO in bytes. + + tx-fifo-depth: + $ref: /schemas/types.yaml#/definitions/uint32 + description: + Size of the TX data FIFO in bytes. + num-cs: $ref: /schemas/types.yaml#/definitions/uint32 description: @@ -52,14 +99,7 @@ properties: description: The SPI controller acts as a slave, instead of a master. -oneOf: - - required: - - "#address-cells" - - required: - - spi-slave - -patternProperties: - "^slave$": + slave: type: object properties: @@ -70,20 +110,13 @@ patternProperties: required: - compatible +patternProperties: "^.*@[0-9a-f]+$": type: object + $ref: spi-peripheral-props.yaml + additionalProperties: true properties: - compatible: - description: - Compatible of the SPI device. - - reg: - minimum: 0 - maximum: 256 - description: - Chip select used by the device. - spi-3wire: $ref: /schemas/types.yaml#/definitions/flag description: @@ -99,66 +132,85 @@ patternProperties: description: The device requires inverse clock polarity (CPOL) mode. - 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. - $ref: /schemas/types.yaml#/definitions/uint32 - enum: [1, 2, 4, 8] - default: 1 - - spi-rx-delay-us: - description: - Delay, in microseconds, after a read transfer. - - spi-tx-bus-width: - description: - Bus width to the SPI bus used for write transfers. - $ref: /schemas/types.yaml#/definitions/uint32 - enum: [1, 2, 4, 8] - default: 1 - - spi-tx-delay-us: - description: - Delay, in microseconds, after a write transfer. - required: - compatible - reg +dependencies: + rx-fifo-depth: [ tx-fifo-depth ] + tx-fifo-depth: [ rx-fifo-depth ] + +allOf: + - if: + not: + required: + - spi-slave + then: + properties: + "#address-cells": + const: 1 + else: + properties: + "#address-cells": + const: 0 + - not: + required: + - fifo-depth + - rx-fifo-depth + - not: + required: + - fifo-depth + - tx-fifo-depth + +additionalProperties: true + examples: - | - spi@f00 { + spi@80010000 { #address-cells = <1>; #size-cells = <0>; - compatible = "fsl,mpc5200b-spi","fsl,mpc5200-spi"; - reg = <0xf00 0x20>; - interrupts = <2 13 0 2 14 0>; - interrupt-parent = <&mpc5200_pic>; - - ethernet-switch@0 { - compatible = "micrel,ks8995m"; + compatible = "fsl,imx28-spi"; + reg = <0x80010000 0x2000>; + interrupts = <96>; + dmas = <&dma_apbh 0>; + dma-names = "rx-tx"; + + display@0 { + compatible = "lg,lg4573"; spi-max-frequency = <1000000>; reg = <0>; }; - codec@1 { - compatible = "ti,tlv320aic26"; + sensor@1 { + compatible = "bosch,bme680"; spi-max-frequency = <100000>; reg = <1>; }; + + flash@2 { + compatible = "jedec,spi-nor"; + spi-max-frequency = <50000000>; + reg = <2>, <3>; + stacked-memories = /bits/ 64 <0x10000000 0x10000000>; + }; + }; + + - | + #include <dt-bindings/gpio/gpio.h> + + spi@20204000 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "brcm,bcm2835-spi"; + reg = <0x7e204000 0x1000>; + interrupts = <2 22>; + clocks = <&clk_spi>; + cs-gpios = <&gpio 8 GPIO_ACTIVE_HIGH>; + + display@0 { + compatible = "lg,lg4573"; + spi-max-frequency = <1000000>; + reg = <0>; + spi-cs-high; + }; }; |