Re: [PATCH v8 1/3] dt-bindings: mfd: Add Gateworks System Controller bindings
From: Lee Jones
Date: Fri Apr 17 2020 - 05:57:37 EST
On Fri, 27 Mar 2020, Tim Harvey wrote:
> This patch adds documentation of device-tree bindings for the
> Gateworks System Controller (GSC).
>
> Signed-off-by: Tim Harvey <tharvey@xxxxxxxxxxxxx>
> ---
> v8:
> - add register to fan-controller node name
>
> v7:
> - change divider from mili-ohms to ohms
> - add constraints for voltage divider and offset
> - remove unnecessary ref for offset
> - renamed fan to fan-controller and changed base prop to reg
>
> v6:
> - fix typo
> - drop invalid description from #interrupt-cells property
> - fix adc pattern property
> - add unit suffix
> - replace hwmon/adc with adc/channel
> - changed adc type to mode and enum int
> - add unit suffix and drop ref for voltage-divider
> - moved fan to its own subnode with base register
>
> v5:
> - resolve dt_binding_check issues
>
> v4:
> - move to using pwm<n>_auto_point<m>_{pwm,temp} for FAN PWM
> - remove unncessary resolution/scaling properties for ADCs
> - update to yaml
> - remove watchdog
>
> v3:
> - replaced _ with -
> - remove input bindings
> - added full description of hwmon
> - fix unit address of hwmon child nodes
> ---
> .../devicetree/bindings/mfd/gateworks-gsc.yaml | 194 +++++++++++++++++++++
> 1 file changed, 194 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mfd/gateworks-gsc.yaml
>
> diff --git a/Documentation/devicetree/bindings/mfd/gateworks-gsc.yaml b/Documentation/devicetree/bindings/mfd/gateworks-gsc.yaml
> new file mode 100644
> index 00000000..a96751c9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/gateworks-gsc.yaml
> @@ -0,0 +1,194 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mfd/gateworks-gsc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Gateworks System Controller multi-function device
I'd prefer if you didn't use Linuxisums in DT docs.
A 'multi-function device' isn't a thing - we made it up.
Nowhere in the documentation [0] is the Gateworks System Controller
described as a multi-function device.
[0] http://trac.gateworks.com/wiki/gsc
> +description: |
> + The GSC is a Multifunction I2C slave device with the following submodules:
No it isn't. It's a:
"The Gateworks System Controller (GSC) is a device present across
various Gateworks product families that provides a set of system
related feature such as the following (refer to the board hardware
user manuals to see what features are present)"
> + - Watchdog Timer
> + - GPIO
> + - Pushbutton controller
> + - Hardware Monitor with ADC's for temperature and voltage rails and
> + fan controller
Why is "Monitor" capitalised, but "controller" is not?
I would s/Monitor/monitor/ here.
> +maintainers:
> + - Tim Harvey <tharvey@xxxxxxxxxxxxx>
> + - Robert Jones <rjones@xxxxxxxxxxxxx>
> +
> +properties:
> + $nodename:
> + pattern: "gsc@[0-9a-f]{1,2}"
> + compatible:
> + const: gw,gsc
> +
> + reg:
> + description: I2C device address
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 1
> +
> + interrupt-controller: true
> +
> + "#interrupt-cells":
> + const: 1
> +
> + "#address-cells":
> + const: 1
> +
> + "#size-cells":
> + const: 0
> +
> + adc:
> + type: object
> + description: Optional Hardware Monitoring module
Again, an odd thing to capitalise.
> + properties:
> + compatible:
> + const: gw,gsc-adc
> +
> + "#address-cells":
> + const: 1
> +
> + "#size-cells":
> + const: 0
> +
> + patternProperties:
> + "^channel@[0-9]+$":
> + type: object
> + description: |
> + Properties for a single ADC which can report cooked values
> + (ie temperature sensor based on thermister), raw values
> + (ie voltage rail with a pre-scaling resistor divider).
/ie/i.e./
> + properties:
> + reg:
> + description: Register of the ADC
> + maxItems: 1
> +
> + label:
> + description: Name of the ADC input
> +
> + gw,mode:
> + description: |
> + conversion mode:
> + 0 - temperature, in C*10
> + 1 - pre-scaled voltage value
> + 2 - scaled voltage based on an optional resistor divider
> + and optional offset
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32
Rob just submitted a patch-set to remove 'allOf's from '$ref'
properties.
> + enum: [0, 1, 2]
> +
> + gw,voltage-divider-ohms:
> + description: values of resistors for divider on raw ADC input
s/values/Values/
> + maxItems: 2
> + items:
> + minimum: 1000
> + maximum: 1000000
> +
> + gw,voltage-offset-microvolt:
> + description: |
> + A positive voltage offset to apply to a raw ADC
> + (ie to compensate for a diode drop).
s/ie/i.e/
> + minimum: 0
> + maximum: 1000000
> +
> + required:
> + - gw,mode
> + - reg
> + - label
> +
> + required:
> + - compatible
> + - "#address-cells"
> + - "#size-cells"
> +
> +patternProperties:
> + "^fan-controller@[0-9a-f]+$":
> + type: object
> + description: Optional FAN controller
"Fan"
> + properties:
> + compatible:
> + const: gw,gsc-fan
> +
> + "#address-cells":
> + const: 1
> +
> + "#size-cells":
> + const: 0
> +
> + reg:
> + description: The fan controller base address
> + maxItems: 1
> +
> + required:
> + - compatible
> + - reg
> + - "#address-cells"
> + - "#size-cells"
> +
> +required:
> + - compatible
> + - reg
> + - interrupts
> + - interrupt-controller
> + - "#interrupt-cells"
> + - "#address-cells"
> + - "#size-cells"
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> + i2c {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + gsc@20 {
> + compatible = "gw,gsc";
> + reg = <0x20>;
> + interrupt-parent = <&gpio1>;
> + interrupts = <4 GPIO_ACTIVE_LOW>;
> + interrupt-controller;
> + #interrupt-cells = <1>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + adc {
> + compatible = "gw,gsc-adc";
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + channel@0 { /* A0: Board Temperature */
> + reg = <0x00>;
> + label = "temp";
> + gw,mode = <0>;
> + };
> +
> + channel@2 { /* A1: Input Voltage (raw ADC) */
> + reg = <0x02>;
> + label = "vdd_vin";
> + gw,mode = <1>;
> + gw,voltage-divider-ohms = <22100 1000>;
> + gw,voltage-offset-microvolt = <800000>;
> + };
> +
> + channel@b { /* A2: Battery voltage */
> + reg = <0x0b>;
> + label = "vdd_bat";
> + gw,mode = <1>;
> + };
> + };
> +
> + fan-controller@2c {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + compatible = "gw,gsc-fan";
> + reg = <0x2c>;
> + };
> + };
> + };
--
Lee Jones [æçæ]
Linaro Services Technical Lead
Linaro.org â Open source software for ARM SoCs
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