[PATCH v9 1/3] dt-bindings: mfd: Add Gateworks System Controller bindings

Tim Harvey
2020-04-30T15:07:42Z

This patch adds documentation of device-tree bindings for the
Gateworks System Controller (GSC).

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
v9:
- added Reviewed-by: Rob Herring <robh@kernel.org>
- remove allOf: see https://lkml.org/lkml/2020/4/15/1930
- encorporate Lee's review comments for item descriptions

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 | 196 +++++++++++++++++++++
1 file changed, 196 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..487a844
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/gateworks-gsc.yaml
@@ -0,0 +1,196 @@
+# 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
+
+description: |
+ The Gateworks System Controller (GSC) is a device present across various
+ Gateworks product families that provides a set of system related features
+ 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
+
+maintainers:
+ - Tim Harvey <tharvey@gateworks.com>
+ - Robert Jones <rjones@gateworks.com>
+
+properties:
+ $nodename:
+ pattern: "gsc@[0-9a-f]{1,2}"
+ compatible:
+ const: gw,gsc
+
+ reg:
+ description: I2C device address
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ interrupt-controller: true
+
+ "#interrupt-cells":
+ const: 1
+
+ "#address-cells":
+ const: 1
+
+ "#size-cells":
+ const: 0
+
+ adc:
+ type: object
+ description: Optional hardware monitoring module
+
+ properties:
+ compatible:
+ const: gw,gsc-adc
+
+ "#address-cells":
+ const: 1
+
+ "#size-cells":
+ const: 0
+
+ patternProperties:
+ "^channel@[0-9]+$":
+ type: object
+ description: |
+ Properties for a single ADC which can report cooked values
+ (i.e. temperature sensor based on thermister), raw values
+ (i.e. voltage rail with a pre-scaling resistor divider).
+
+ 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
+ $ref: /schemas/types.yaml#/definitions/uint32
+ enum: [0, 1, 2]
+
+ gw,voltage-divider-ohms:
+ description: Values of resistors for divider on raw ADC input
+ maxItems: 2
+ items:
+ minimum: 1000
+ maximum: 1000000
+
+ gw,voltage-offset-microvolt:
+ description: |
+ A positive voltage offset to apply to a raw ADC
+ (i.e. to compensate for a diode drop).
+ minimum: 0
+ maximum: 1000000
+
+ required:
+ - gw,mode
+ - reg
+ - label
+
+ required:
+ - compatible
+ - "#address-cells"
+ - "#size-cells"
+
+patternProperties:
+ "^fan-controller@[0-9a-f]+$":
+ type: object
+ description: Optional fan controller
+
+ 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>;
+ };
+ };
+ };
--
2.7.4