From 0a1b929356830257568f9547e173f0e7498060ea Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Mon, 20 May 2019 16:50:33 +0200 Subject: [PATCH] spi: Add YAML schemas for the generic SPI options The SPI controllers have a bunch of generic options that are needed in a device tree. Add a YAML schemas for those. Signed-off-by: Maxime Ripard Reviewed-by: Rob Herring Signed-off-by: Mark Brown --- Documentation/devicetree/bindings/spi/spi-bus.txt | 112 +------------- .../devicetree/bindings/spi/spi-controller.yaml | 161 +++++++++++++++++++++ 2 files changed, 162 insertions(+), 111 deletions(-) create mode 100644 Documentation/devicetree/bindings/spi/spi-controller.yaml diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt index 1f6e86f787ef..e07783505498 100644 --- a/Documentation/devicetree/bindings/spi/spi-bus.txt +++ b/Documentation/devicetree/bindings/spi/spi-bus.txt @@ -1,111 +1 @@ -SPI (Serial Peripheral Interface) busses - -SPI busses can be described with a node for the SPI controller device -and a set of child nodes for each SPI slave on the bus. The system's SPI -controller may be described for use in SPI master mode or in SPI slave mode, -but not for both at the same time. - -The SPI controller node requires the following properties: -- compatible - Name of SPI bus controller following generic names - recommended practice. - -In master mode, the SPI controller node requires the following additional -properties: -- #address-cells - number of cells required to define a chip select - address on the SPI bus. -- #size-cells - should be zero. - -In slave mode, the SPI controller node requires one additional property: -- spi-slave - Empty property. - -No other properties are required in the SPI bus node. It is assumed -that a driver for an SPI bus device will understand that it is an SPI bus. -However, the binding does not attempt to define the specific method for -assigning chip select numbers. Since SPI chip select configuration is -flexible and non-standardized, it is left out of this binding with the -assumption that board specific platform code will be used to manage -chip selects. Individual drivers can define additional properties to -support describing the chip select layout. - -Optional properties (master mode only): -- cs-gpios - gpios chip select. -- num-cs - total number of chipselects. - -If cs-gpios is used the number of chip selects will be increased automatically -with max(cs-gpios > hw cs). - -So if for example the controller has 2 CS lines, and the cs-gpios -property looks like this: - -cs-gpios = <&gpio1 0 0>, <0>, <&gpio1 1 0>, <&gpio1 2 0>; - -Then it should be configured so that num_chipselect = 4 with the -following mapping: - -cs0 : &gpio1 0 0 -cs1 : native -cs2 : &gpio1 1 0 -cs3 : &gpio1 2 0 - - -SPI slave nodes must be children of the SPI controller node. - -In master mode, one or more slave nodes (up to the number of chip selects) can -be present. Required properties are: -- compatible - Name of SPI device following generic names recommended - practice. -- reg - Chip select address of device. -- spi-max-frequency - Maximum SPI clocking speed of device in Hz. - -In slave mode, the (single) slave node is optional. -If present, it must be called "slave". Required properties are: -- compatible - Name of SPI device following generic names recommended - practice. - -All slave nodes can contain the following optional properties: -- spi-cpol - Empty property indicating device requires inverse clock - polarity (CPOL) mode. -- spi-cpha - Empty property indicating device requires shifted clock - phase (CPHA) mode. -- spi-cs-high - Empty property indicating device requires chip select - active high. -- spi-3wire - Empty property indicating device requires 3-wire mode. -- spi-lsb-first - Empty property indicating device requires LSB first mode. -- spi-tx-bus-width - The bus width (number of data wires) that is used for MOSI. - Defaults to 1 if not present. -- spi-rx-bus-width - The bus width (number of data wires) that is used for MISO. - Defaults to 1 if not present. -- spi-rx-delay-us - Microsecond delay after a read transfer. -- spi-tx-delay-us - Microsecond delay after a write transfer. - -Some SPI controllers and devices support Dual and Quad SPI transfer mode. -It allows data in the SPI system to be transferred using 2 wires (DUAL) or 4 -wires (QUAD). -Now the value that spi-tx-bus-width and spi-rx-bus-width can receive is -only 1 (SINGLE), 2 (DUAL) and 4 (QUAD). -Dual/Quad mode is not allowed when 3-wire mode is used. - -If a gpio chipselect is used for the SPI slave the gpio number will be passed -via the SPI master node cs-gpios property. - -SPI example for an MPC5200 SPI bus: - spi@f00 { - #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"; - spi-max-frequency = <1000000>; - reg = <0>; - }; - - codec@1 { - compatible = "ti,tlv320aic26"; - spi-max-frequency = <100000>; - reg = <1>; - }; - }; +This file has moved to spi-controller.yaml. diff --git a/Documentation/devicetree/bindings/spi/spi-controller.yaml b/Documentation/devicetree/bindings/spi/spi-controller.yaml new file mode 100644 index 000000000000..876c0623f322 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/spi-controller.yaml @@ -0,0 +1,161 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/spi/spi-controller.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: SPI Controller Generic Binding + +maintainers: + - Mark Brown + +description: | + SPI busses can be described with a node for the SPI controller device + and a set of child nodes for each SPI slave on the bus. The system SPI + controller may be described for use in SPI master mode or in SPI slave mode, + but not for both at the same time. + +properties: + $nodename: + pattern: "^spi(@.*|-[0-9a-f])*$" + + "#address-cells": + const: 1 + + "#size-cells": + const: 0 + + cs-gpios: + description: | + GPIOs used as chip selects. + If that property is used, the number of chip selects will be + increased automatically with max(cs-gpios, hardware chip selects). + + So if, for example, the controller has 2 CS lines, and the + cs-gpios looks like this + cs-gpios = <&gpio1 0 0>, <0>, <&gpio1 1 0>, <&gpio1 2 0>; + + Then it should be configured so that num_chipselect = 4, with + the following mapping + cs0 : &gpio1 0 0 + cs1 : native + cs2 : &gpio1 1 0 + cs3 : &gpio1 2 0 + + num-cs: + $ref: /schemas/types.yaml#/definitions/uint32 + description: + Total number of chip selects. + + spi-slave: + $ref: /schemas/types.yaml#/definitions/flag + description: + The SPI controller acts as a slave, instead of a master. + +patternProperties: + "^slave$": + type: object + + properties: + compatible: + description: + Compatible of the SPI device. + + required: + - compatible + + "^.*@[0-9a-f]+$": + type: object + + properties: + compatible: + description: + Compatible of the SPI device. + + reg: + maxItems: 1 + minimum: 0 + maximum: 256 + description: + Chip select used by the device. + + spi-3wire: + $ref: /schemas/types.yaml#/definitions/flag + description: + The device requires 3-wire mode. + + spi-cpha: + $ref: /schemas/types.yaml#/definitions/flag + description: + The device requires shifted clock phase (CPHA) mode. + + spi-cpol: + $ref: /schemas/types.yaml#/definitions/flag + 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: + allOf: + - $ref: /schemas/types.yaml#/definitions/uint32 + - enum: [ 1, 2, 4 ] + - default: 1 + description: + Bus width to the SPI bus used for MISO. + + spi-rx-delay-us: + description: + Delay, in microseconds, after a read transfer. + + spi-tx-bus-width: + allOf: + - $ref: /schemas/types.yaml#/definitions/uint32 + - enum: [ 1, 2, 4 ] + - default: 1 + description: + Bus width to the SPI bus used for MOSI. + + spi-tx-delay-us: + description: + Delay, in microseconds, after a write transfer. + + required: + - compatible + - reg + +examples: + - | + spi@f00 { + #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"; + spi-max-frequency = <1000000>; + reg = <0>; + }; + + codec@1 { + compatible = "ti,tlv320aic26"; + spi-max-frequency = <100000>; + reg = <1>; + }; + }; -- 2.11.0