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author | Thierry Reding <treding@nvidia.com> | 2021-12-17 19:56:56 +0300 |
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committer | Rob Herring <robh@kernel.org> | 2021-12-18 01:39:33 +0300 |
commit | 8b82b8416f2cb1fdfa2709c7a96e022561e3ed24 (patch) | |
tree | 3c8807c8845ff781fc17f2c59182cc3c9a0bf499 /Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.yaml | |
parent | f10a9b722f808dd3a02648f073a84b2fe56dddd4 (diff) | |
download | linux-8b82b8416f2cb1fdfa2709c7a96e022561e3ed24.tar.xz |
dt-bindings: i2c: i2c-mux-pinctrl: Convert to json-schema
Convert the pinctrl-based I2C mux bindings from the free-form text
format to json-schema.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211217165658.2650677-2-thierry.reding@gmail.com
Diffstat (limited to 'Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.yaml')
-rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.yaml | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.yaml b/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.yaml new file mode 100644 index 000000000000..2e3d555eb96c --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.yaml @@ -0,0 +1,103 @@ +# SPDX-License-Identifier: GPL-2.0-only +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/i2c/i2c-mux-pinctrl.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Pinctrl-based I2C Bus Mux + +maintainers: + - Wolfram Sang <wsa@kernel.org> + +description: | + This binding describes an I2C bus multiplexer that uses pin multiplexing to route the I2C + signals, and represents the pin multiplexing configuration using the pinctrl device tree + bindings. + + +-----+ +-----+ + | dev | | dev | + +------------------------+ +-----+ +-----+ + | SoC | | | + | /----|------+--------+ + | +---+ +------+ | child bus A, on first set of pins + | |I2C|---|Pinmux| | + | +---+ +------+ | child bus B, on second set of pins + | \----|------+--------+--------+ + | | | | | + +------------------------+ +-----+ +-----+ +-----+ + | dev | | dev | | dev | + +-----+ +-----+ +-----+ + + For each named state defined in the pinctrl-names property, an I2C child bus will be created. + I2C child bus numbers are assigned based on the index into the pinctrl-names property. + + The only exception is that no bus will be created for a state named "idle". If such a state is + defined, it must be the last entry in pinctrl-names. For example: + + pinctrl-names = "ddc", "pta", "idle" -> ddc = bus 0, pta = bus 1 + pinctrl-names = "ddc", "idle", "pta" -> Invalid ("idle" not last) + pinctrl-names = "idle", "ddc", "pta" -> Invalid ("idle" not last) + + Whenever an access is made to a device on a child bus, the relevant pinctrl state will be + programmed into hardware. + + If an idle state is defined, whenever an access is not being made to a device on a child bus, + the idle pinctrl state will be programmed into hardware. + + If an idle state is not defined, the most recently used pinctrl state will be left programmed + into hardware whenever no access is being made of a device on a child bus. + +properties: + compatible: + const: i2c-mux-pinctrl + + i2c-parent: + $ref: /schemas/types.yaml#/definitions/phandle + description: The phandle of the I2C bus that this multiplexer's master-side port is connected + to. + +allOf: + - $ref: i2c-mux.yaml + +unevaluatedProperties: false + +required: + - compatible + - i2c-parent + +examples: + - | + i2cmux { + compatible = "i2c-mux-pinctrl"; + #address-cells = <1>; + #size-cells = <0>; + + i2c-parent = <&i2c1>; + + pinctrl-names = "ddc", "pta", "idle"; + pinctrl-0 = <&state_i2cmux_ddc>; + pinctrl-1 = <&state_i2cmux_pta>; + pinctrl-2 = <&state_i2cmux_idle>; + + i2c@0 { + reg = <0>; + #address-cells = <1>; + #size-cells = <0>; + + eeprom@50 { + compatible = "atmel,24c02"; + reg = <0x50>; + }; + }; + + i2c@1 { + reg = <1>; + #address-cells = <1>; + #size-cells = <0>; + + eeprom@50 { + compatible = "atmel,24c02"; + reg = <0x50>; + }; + }; + }; |