On Mon, Feb 05, 2024 at 11:09:20AM -0600, Danny Kaehn wrote: > This is a USB HID device which includes an I2C controller and 8 GPIO pins. > > The binding allows describing the chip's gpio and i2c controller in DT > using the subnodes named "gpio" and "i2c", respectively. This is > intended to be used in configurations where the CP2112 is permanently > connected in hardware. > > Signed-off-by: Danny Kaehn <danny.kaehn@xxxxxxxxxx> > --- > > Note -- Reviewed-By tags have been removed as suggested by Benjamin, since > 1. It has been 6+ months since this binding was reviewed, and a lot can > change upstream in that time > 2. There has been some contention between using named child nodes to > identify i2c and gpio nodes, and also making the driver implementing this > binding compatible with ACPI, since names aren't significant for ACPI > nodes, and ACPI names are always automatically uppercased. It has been > suggested that perhaps the DT binding should use child nodes with > addressable `reg` properties to identify the child nodes, instead of by > name [1]. 'reg' only makes sense if there are values which relate to the h/w. If your addresses are indices, that will be suspect. There's documented nodenames for specific device classes in DT. You have to use those whether there's 'reg' and a unit-address or not. I'm not really clear what the problem is. > > Of course, I acknowledge that other firmware languages and kernel details > shouldn't impact DT bindings, but it also seems that there should > be some consistent way to specify sub-functions like this accross DT > and ACPI. Some additional commentary / requests for comment about the > seemingly missing glue here can be found in [2]. I have little interest in worrying about ACPI as I have limited knowledge in ACPI requirements, what I do know is the model for bindings are fundamentally differ, and no one has stepped up to maintain bindings from an ACPI perspective. > Any comments from Rob/Krzysztof/other DT folks would be greatly appreciated > > [1] https://lore.kernel.org/all/ZBhoHzTr5l38u%2FkX@xxxxxxxxxxxxxxxxxx/ > [2] https://lore.kernel.org/all/CAP+ZCCd0cD+q7=ngyEzScAte2VT9R00mqCQxB3K2TMbeg8UAfA@xxxxxxxxxxxxxx/ > > .../bindings/i2c/silabs,cp2112.yaml | 113 ++++++++++++++++++ > 1 file changed, 113 insertions(+) > create mode 100644 Documentation/devicetree/bindings/i2c/silabs,cp2112.yaml > > diff --git a/Documentation/devicetree/bindings/i2c/silabs,cp2112.yaml b/Documentation/devicetree/bindings/i2c/silabs,cp2112.yaml > new file mode 100644 > index 000000000000..a27509627804 > --- /dev/null > +++ b/Documentation/devicetree/bindings/i2c/silabs,cp2112.yaml > @@ -0,0 +1,113 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/i2c/silabs,cp2112.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: CP2112 HID USB to SMBus/I2C Bridge > + > +maintainers: > + - Danny Kaehn <kaehndan@xxxxxxxxx> > + > +description: > + The CP2112 is a USB HID device which includes an integrated I2C controller > + and 8 GPIO pins. Its GPIO pins can each be configured as inputs, open-drain > + outputs, or push-pull outputs. > + > +properties: > + compatible: > + const: usb10c4,ea90 > + > + reg: > + maxItems: 1 > + description: The USB port number on the host controller > + > + i2c: > + description: The SMBus/I2C controller node for the CP2112 > + $ref: /schemas/i2c/i2c-controller.yaml# > + unevaluatedProperties: false > + > + properties: > + sda-gpios: > + maxItems: 1 > + > + scl-gpios: > + maxItems: 1 Why do you have GPIOs if this is a proper controller? > + > + clock-frequency: > + minimum: 10000 > + default: 100000 > + maximum: 400000 > + > + gpio: > + description: The GPIO controller node for the CP2112 There's no need for a child node here. All these properties can be part of the parent. > + type: object > + unevaluatedProperties: false > + > + properties: > + interrupt-controller: true > + "#interrupt-cells": > + const: 2 > + > + gpio-controller: true > + "#gpio-cells": > + const: 2 > + > + gpio-line-names: > + minItems: 1 > + maxItems: 8 > + > + patternProperties: > + "-hog(-[0-9]+)?$": > + type: object > + > + required: > + - gpio-hog > + > +required: > + - compatible > + - reg > + > +additionalProperties: false > + > +examples: > + - | > + #include <dt-bindings/interrupt-controller/irq.h> > + #include <dt-bindings/gpio/gpio.h> > + > + usb { > + #address-cells = <1>; > + #size-cells = <0>; > + > + device@1 { > + compatible = "usb10c4,ea90"; > + reg = <1>; > + > + i2c { > + #address-cells = <1>; > + #size-cells = <0>; > + sda-gpios = <&cp2112_gpio 0 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>; > + scl-gpios = <&cp2112_gpio 1 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>; > + > + temp@48 { > + compatible = "national,lm75"; > + reg = <0x48>; > + }; > + }; > + > + cp2112_gpio: gpio { > + gpio-controller; > + interrupt-controller; > + #gpio-cells = <2>; > + gpio-line-names = "CP2112_SDA", "CP2112_SCL", "TEST2", > + "TEST3","TEST4", "TEST5", "TEST6"; > + > + fan-rst-hog { > + gpio-hog; > + gpios = <7 GPIO_ACTIVE_HIGH>; > + output-high; > + line-name = "FAN_RST"; > + }; > + }; > + }; > + }; > -- > 2.25.1 >
