Re: [PATCH 4/6] dt-bindings: i2c: Convert i2c-mux bindings to DT schema
From: Laurent Pinchart
Date: Tue May 18 2021 - 21:39:17 EST
Hi Rob,
Thank you for the patch.
On Tue, May 18, 2021 at 06:28:56PM -0500, Rob Herring wrote:
> As some of the example I2C devices don't have schemas yet, change them to
> ones that do.
>
> Cc: Peter Rosin <peda@xxxxxxxxxx>
> Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
> ---
> .../bindings/i2c/i2c-demux-pinctrl.txt | 2 +-
> .../devicetree/bindings/i2c/i2c-mux-gpio.txt | 4 +-
> .../devicetree/bindings/i2c/i2c-mux-gpmux.txt | 99 --------------
> .../bindings/i2c/i2c-mux-gpmux.yaml | 124 ++++++++++++++++++
> .../bindings/i2c/i2c-mux-ltc4306.txt | 4 +-
> .../bindings/i2c/i2c-mux-pinctrl.txt | 4 +-
> .../devicetree/bindings/i2c/i2c-mux-reg.txt | 4 +-
> .../devicetree/bindings/i2c/i2c-mux.txt | 73 -----------
> .../devicetree/bindings/i2c/i2c-mux.yaml | 87 ++++++++++++
> 9 files changed, 220 insertions(+), 181 deletions(-)
> delete mode 100644 Documentation/devicetree/bindings/i2c/i2c-mux-gpmux.txt
> create mode 100644 Documentation/devicetree/bindings/i2c/i2c-mux-gpmux.yaml
> delete mode 100644 Documentation/devicetree/bindings/i2c/i2c-mux.txt
> create mode 100644 Documentation/devicetree/bindings/i2c/i2c-mux.yaml
>
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-demux-pinctrl.txt b/Documentation/devicetree/bindings/i2c/i2c-demux-pinctrl.txt
> index 81b5d55086fa..86b2e433a969 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-demux-pinctrl.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-demux-pinctrl.txt
> @@ -27,7 +27,7 @@ Required properties:
> - i2c-bus-name: The name of this bus. Also needed as pinctrl-name for the I2C
> parents.
>
> -Furthermore, I2C mux properties and child nodes. See i2c-mux.txt in this
> +Furthermore, I2C mux properties and child nodes. See i2c-mux.yaml in this
> directory.
>
> Example:
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-gpio.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-gpio.txt
> index 21da3ecbb370..e00d2b9e957a 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mux-gpio.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-gpio.txt
> @@ -22,8 +22,8 @@ Required properties:
> - i2c-parent: The phandle of the I2C bus that this multiplexer's master-side
> port is connected to.
> - mux-gpios: list of gpios used to control the muxer
> -* Standard I2C mux properties. See i2c-mux.txt in this directory.
> -* I2C child bus nodes. See i2c-mux.txt in this directory.
> +* Standard I2C mux properties. See i2c-mux.yaml in this directory.
> +* I2C child bus nodes. See i2c-mux.yaml in this directory.
>
> Optional properties:
> - idle-state: value to set the muxer to when idle. When no value is
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-gpmux.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-gpmux.txt
> deleted file mode 100644
> index 057083a8ba17..000000000000
> --- a/Documentation/devicetree/bindings/i2c/i2c-mux-gpmux.txt
> +++ /dev/null
> @@ -1,99 +0,0 @@
> -General Purpose I2C Bus Mux
> -
> -This binding describes an I2C bus multiplexer that uses a mux controller
> -from the mux subsystem to route the I2C signals.
> -
> - .-----. .-----.
> - | dev | | dev |
> - .------------. '-----' '-----'
> - | SoC | | |
> - | | .--------+--------'
> - | .------. | .------+ child bus A, on MUX value set to 0
> - | | I2C |-|--| Mux |
> - | '------' | '--+---+ child bus B, on MUX value set to 1
> - | .------. | | '----------+--------+--------.
> - | | MUX- | | | | | |
> - | | Ctrl |-|-----+ .-----. .-----. .-----.
> - | '------' | | dev | | dev | | dev |
> - '------------' '-----' '-----' '-----'
> -
> -Required properties:
> -- compatible: i2c-mux
> -- i2c-parent: The phandle of the I2C bus that this multiplexer's master-side
> - port is connected to.
> -- mux-controls: The phandle of the mux controller to use for operating the
> - mux.
> -* Standard I2C mux properties. See i2c-mux.txt in this directory.
> -* I2C child bus nodes. See i2c-mux.txt in this directory. The sub-bus number
> - is also the mux-controller state described in ../mux/mux-controller.yaml
> -
> -Optional properties:
> -- mux-locked: If present, explicitly allow unrelated I2C transactions on the
> - parent I2C adapter at these times:
> - + during setup of the multiplexer
> - + between setup of the multiplexer and the child bus I2C transaction
> - + between the child bus I2C transaction and releasing of the multiplexer
> - + during releasing of the multiplexer
> - However, I2C transactions to devices behind all I2C multiplexers connected
> - to the same parent adapter that this multiplexer is connected to are blocked
> - for the full duration of the complete multiplexed I2C transaction (i.e.
> - including the times covered by the above list).
> - If mux-locked is not present, the multiplexer is assumed to be parent-locked.
> - This means that no unrelated I2C transactions are allowed on the parent I2C
> - adapter for the complete multiplexed I2C transaction.
> - The properties of mux-locked and parent-locked multiplexers are discussed
> - in more detail in Documentation/i2c/i2c-topology.rst.
> -
> -For each i2c child node, an I2C child bus will be created. They will
> -be numbered based on their order in the device tree.
> -
> -Whenever an access is made to a device on a child bus, the value set
> -in the relevant node's reg property will be set as the state in the
> -mux controller.
> -
> -Example:
> - mux: mux-controller {
> - compatible = "gpio-mux";
> - #mux-control-cells = <0>;
> -
> - mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,
> - <&pioA 1 GPIO_ACTIVE_HIGH>;
> - };
> -
> - i2c-mux {
> - compatible = "i2c-mux";
> - mux-locked;
> - i2c-parent = <&i2c1>;
> -
> - mux-controls = <&mux>;
> -
> - #address-cells = <1>;
> - #size-cells = <0>;
> -
> - i2c@1 {
> - reg = <1>;
> - #address-cells = <1>;
> - #size-cells = <0>;
> -
> - ssd1307: oled@3c {
> - compatible = "solomon,ssd1307fb-i2c";
> - reg = <0x3c>;
> - pwms = <&pwm 4 3000>;
> - reset-gpios = <&gpio2 7 1>;
> - reset-active-low;
> - };
> - };
> -
> - i2c@3 {
> - reg = <3>;
> - #address-cells = <1>;
> - #size-cells = <0>;
> -
> - pca9555: pca9555@20 {
> - compatible = "nxp,pca9555";
> - gpio-controller;
> - #gpio-cells = <2>;
> - reg = <0x20>;
> - };
> - };
> - };
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-gpmux.yaml b/Documentation/devicetree/bindings/i2c/i2c-mux-gpmux.yaml
> new file mode 100644
> index 000000000000..3e6ea59aea68
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-gpmux.yaml
> @@ -0,0 +1,124 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/i2c/i2c-mux-gpmux.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: General Purpose I2C Bus Mux
> +
> +maintainers:
> + - Peter Rosin <peda@xxxxxxxxxx>
> +
> +description: |+
> + This binding describes an I2C bus multiplexer that uses a mux controller
> + from the mux subsystem to route the I2C signals.
> +
> + .-----. .-----.
> + | dev | | dev |
> + .------------. '-----' '-----'
> + | SoC | | |
> + | | .--------+--------'
> + | .------. | .------+ child bus A, on MUX value set to 0
> + | | I2C |-|--| Mux |
> + | '------' | '--+---+ child bus B, on MUX value set to 1
> + | .------. | | '----------+--------+--------.
> + | | MUX- | | | | | |
> + | | Ctrl |-|-----+ .-----. .-----. .-----.
> + | '------' | | dev | | dev | | dev |
> + '------------' '-----' '-----' '-----'
> +
> +
> +
> +allOf:
> + - $ref: /schemas/i2c/i2c-mux.yaml#
> +
> +properties:
> + compatible:
> + const: i2c-mux
> +
> + 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.
> +
> + mux-controls:
> + maxItems: 1
> + description:
> + The mux-controller states are the I2C sub-bus numbers.
> +
> + mux-locked:
> + type: boolean
> + description: |
> + Explicitly allow unrelated I2C transactions on the parent I2C adapter at
> + these times:
> + + during setup of the multiplexer
> + + between setup of the multiplexer and the child bus I2C transaction
> + + between the child bus I2C transaction and releasing of the multiplexer
> + + during releasing of the multiplexer
> +
> + However, I2C transactions to devices behind all I2C multiplexers connected
> + to the same parent adapter that this multiplexer is connected to are blocked
> + for the full duration of the complete multiplexed I2C transaction (i.e.
> + including the times covered by the above list).
> + If mux-locked is not present, the multiplexer is assumed to be parent-locked.
> + This means that no unrelated I2C transactions are allowed on the parent I2C
> + adapter for the complete multiplexed I2C transaction.
> + The properties of mux-locked and parent-locked multiplexers are discussed
> + in more detail in Documentation/i2c/i2c-topology.rst.
> +
> +required:
> + - compatible
> + - i2c-parent
> + - mux-controls
> +
> +unevaluatedProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> + mux: mux-controller {
> + compatible = "gpio-mux";
> + #mux-control-cells = <0>;
> +
> + mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,
> + <&pioA 1 GPIO_ACTIVE_HIGH>;
> + };
> +
> + i2c-mux {
> + compatible = "i2c-mux";
> + mux-locked;
> + i2c-parent = <&i2c1>;
> +
> + mux-controls = <&mux>;
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + i2c@1 {
> + reg = <1>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + gpio@20 {
> + compatible = "nxp,pca9555";
> + gpio-controller;
> + #gpio-cells = <2>;
> + reg = <0x20>;
> + };
> + };
> +
> + i2c@3 {
> + reg = <3>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + gpio@20 {
> + compatible = "nxp,pca9555";
> + gpio-controller;
> + #gpio-cells = <2>;
> + reg = <0x20>;
> + };
> + };
> + };
> +...
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-ltc4306.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-ltc4306.txt
> index 8b1e49cdce3f..29c4550c9782 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mux-ltc4306.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-ltc4306.txt
> @@ -8,8 +8,8 @@ Required Properties:
>
> The following required properties are defined externally:
>
> - - Standard I2C mux properties. See i2c-mux.txt in this directory.
> - - I2C child bus nodes. See i2c-mux.txt in this directory.
> + - Standard I2C mux properties. See i2c-mux.yaml in this directory.
> + - I2C child bus nodes. See i2c-mux.yaml in this directory.
>
> Optional Properties:
>
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.txt
> index 33119a98e144..997a287ed3f6 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.txt
> @@ -28,9 +28,9 @@ Also required are:
> * Standard pinctrl properties that specify the pin mux state for each child
> bus. See ../pinctrl/pinctrl-bindings.txt.
>
> -* Standard I2C mux properties. See i2c-mux.txt in this directory.
> +* Standard I2C mux properties. See i2c-mux.yaml in this directory.
>
> -* I2C child bus nodes. See i2c-mux.txt in this directory.
> +* I2C child bus nodes. See i2c-mux.yaml in this directory.
>
> 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
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-reg.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-reg.txt
> index de00d7fc450b..b9d9755e4172 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mux-reg.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-reg.txt
> @@ -7,8 +7,8 @@ Required properties:
> - compatible: i2c-mux-reg
> - i2c-parent: The phandle of the I2C bus that this multiplexer's master-side
> port is connected to.
> -* Standard I2C mux properties. See i2c-mux.txt in this directory.
> -* I2C child bus nodes. See i2c-mux.txt in this directory.
> +* Standard I2C mux properties. See i2c-mux.yaml in this directory.
> +* I2C child bus nodes. See i2c-mux.yaml in this directory.
>
> Optional properties:
> - reg: this pair of <offset size> specifies the register to control the mux.
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux.txt b/Documentation/devicetree/bindings/i2c/i2c-mux.txt
> deleted file mode 100644
> index b38f58a1c878..000000000000
> --- a/Documentation/devicetree/bindings/i2c/i2c-mux.txt
> +++ /dev/null
> @@ -1,73 +0,0 @@
> -Common i2c bus multiplexer/switch properties.
> -
> -An i2c bus multiplexer/switch will have several child busses that are
> -numbered uniquely in a device dependent manner. The nodes for an i2c bus
> -multiplexer/switch will have one child node for each child bus.
> -
> -Optional properties:
> -- #address-cells = <1>;
> - This property is required if the i2c-mux child node does not exist.
> -
> -- #size-cells = <0>;
> - This property is required if the i2c-mux child node does not exist.
> -
> -- i2c-mux
> - For i2c multiplexers/switches that have child nodes that are a mixture
> - of both i2c child busses and other child nodes, the 'i2c-mux' subnode
> - can be used for populating the i2c child busses. If an 'i2c-mux'
> - subnode is present, only subnodes of this will be considered as i2c
> - child busses.
> -
> -Required properties for the i2c-mux child node:
> -- #address-cells = <1>;
> -- #size-cells = <0>;
> -
> -Required properties for i2c child bus nodes:
> -- #address-cells = <1>;
> -- #size-cells = <0>;
> -- reg : The sub-bus number.
> -
> -Optional properties for i2c child bus nodes:
> -- Other properties specific to the multiplexer/switch hardware.
> -- Child nodes conforming to i2c bus binding
> -
> -
> -Example :
> -
> - /*
> - An NXP pca9548 8 channel I2C multiplexer at address 0x70
> - with two NXP pca8574 GPIO expanders attached, one each to
> - ports 3 and 4.
> - */
> -
> - mux@70 {
> - compatible = "nxp,pca9548";
> - reg = <0x70>;
> - #address-cells = <1>;
> - #size-cells = <0>;
> -
> - i2c@3 {
> - #address-cells = <1>;
> - #size-cells = <0>;
> - reg = <3>;
> -
> - gpio1: gpio@38 {
> - compatible = "nxp,pca8574";
> - reg = <0x38>;
> - #gpio-cells = <2>;
> - gpio-controller;
> - };
> - };
> - i2c@4 {
> - #address-cells = <1>;
> - #size-cells = <0>;
> - reg = <4>;
> -
> - gpio2: gpio@38 {
> - compatible = "nxp,pca8574";
> - reg = <0x38>;
> - #gpio-cells = <2>;
> - gpio-controller;
> - };
> - };
> - };
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux.yaml b/Documentation/devicetree/bindings/i2c/i2c-mux.yaml
> new file mode 100644
> index 000000000000..3aa4d84a6610
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mux.yaml
> @@ -0,0 +1,87 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/i2c/i2c-mux.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Common i2c bus multiplexer/switch properties.
> +
> +maintainers:
> + - Peter Rosin <peda@xxxxxxxxxx>
> +
> +description: |+
> + An i2c bus multiplexer/switch will have several child busses that are numbered
> + uniquely in a device dependent manner. The nodes for an i2c bus
> + multiplexer/switch will have one child node for each child bus.
> +
> + For i2c multiplexers/switches that have child nodes that are a mixture of both
> + i2c child busses and other child nodes, the 'i2c-mux' subnode can be used for
> + populating the i2c child busses. If an 'i2c-mux' subnode is present, only
> + subnodes of this will be considered as i2c child busses.
As I understand this, it means that child nodes corresponding to child
buses can be either direct children of the I2C mux node, or grouped in a
i2c-mux node (the same way we optionally group the 'port' nodes in a
'ports' node). This doesn't seem to be supported by the bindings below.
> +
> +properties:
> + $nodename:
> + pattern: '^(i2c-?)?mux'
> +
> + '#address-cells':
> + const: 1
> +
> + '#size-cells':
> + const: 0
> +
> +patternProperties:
> + '^i2c@[0-9a-f]+$':
> + $ref: /schemas/i2c/i2c-controller.yaml
> + unevaluatedProperties: false
> +
> + properties:
> + reg:
> + description: The mux selector sub-bus number for the child I2C bus.
> + maxItems: 1
> +
> +additionalProperties: true
> +
> +examples:
> + - |
> + /*
> + An NXP pca9548 8 channel I2C multiplexer at address 0x70
> + with two NXP pca8574 GPIO expanders attached, one each to
> + ports 3 and 4.
I'd add the missing * while at it.
> + */
> + i2c {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + i2c-mux@70 {
> + compatible = "nxp,pca9548";
> + reg = <0x70>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + i2c@3 {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + reg = <3>;
> +
> + gpio@20 {
> + compatible = "nxp,pca9555";
> + gpio-controller;
> + #gpio-cells = <2>;
> + reg = <0x20>;
> + };
> + };
> + i2c@4 {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + reg = <4>;
> +
> + gpio@20 {
> + compatible = "nxp,pca9555";
> + gpio-controller;
> + #gpio-cells = <2>;
> + reg = <0x20>;
> + };
> + };
> + };
> + };
> +...
--
Regards,
Laurent Pinchart