[PATCH v3 1/4] dt-bindings: hwmon: Add Aspeed AST2600 PWM/Fan
From: Andrew Jeffery <hidden>
Date: 2021-01-22 04:29:12
Also in:
linux-arm-kernel, lkml, openbmc
On Mon, 18 Jan 2021, at 17:20, Troy Lee wrote:
quoted hunk ↗ jump to hunk
We add binding for supporting a new AST2600 PWM/Fan hwmon driver. Changes since v2: - Fixed yamllint warnings/errors Changes since v1: - dt binding with DT schema format Signed-off-by: Troy Lee <redacted> Reported-by: Rob Herring <robh@kernel.org> --- .../hwmon/aspeed,ast2600-pwm-tachometer.yaml | 131 ++++++++++++++++++ 1 file changed, 131 insertions(+) create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,ast2600-pwm-tachometer.yamldiff --gita/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-pwm-tachometer.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-pwm-tachometer.yaml new file mode 100644 index 000000000000..fa5340f5a43f--- /dev/null +++b/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-pwm-tachometer.yaml@@ -0,0 +1,131 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- + +$id:http://devicetree.org/schemas/hwmon/aspeed,ast2600-pwm-tachometer.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: ASPEED AST2600 PWM and Fan Tacho controller device driver + +maintainers: + - Ryan Chen [off-list ref] + +description: | + The ASPEED PWM controller can support upto 16 PWM outputs. The ASPEED Fan Tacho + controller can support upto 16 Fan tachometer inputs. + There can be upto 16 fans supported. Each fan can have one PWM output and + one Fan tach inputs. + +properties: + compatible: + const: aspeed,ast2600-pwm-tachometer + + "#address-cells": + const: 1 + + "#size-cells": + const: 0 + + "#cooling-cells": + const: 2 + + reg: + maxItems: 1 + + clocks: + maxItems: 1 + + resets: + maxItems: 1 + +patternProperties: + "^fan@[0-9a-f]$": + type: object + description: + Under fan subnode there can upto 16 child nodes, with each child node + representing a fan. There are 16 fans each fan can have one PWM port and one + Fan tach inputs. + For PWM port can be configured cooling-levels to create cooling device. + Cooling device could be bound to a thermal zone for the thermal control. + + properties: + reg: + minimum: 0 + maximum: 15 + description: + This property identify the PWM control channel of this fan. + + fan-tach-ch: + $ref: /schemas/types.yaml#/definitions/uint8 + minimum: 0 + maximum: 15 + description: + This property identify the fan tach input channel. + + pulses-per-revolution: + $ref: /schemas/types.yaml#/definitions/uint32 + default: 2 + minimum: 1 + description: + Specify tacho pulse per revolution of the fan. + + cooling-levels: + description: + PWM duty cycle values in a range from 0 to 255 + which correspond to thermal cooling states. + + aspeed,pwm-freq-hz: + default: 25000 + minimum: 24 + maximum: 780000 + description: + Specify the frequency of PWM.
What about using 'bus-frequency' instead?
+ + aspeed,inverse-pin: + type: boolean + description: + Inverse PWM output signal.
What's the benefit? I know the hardware provides the function, but do we need to expose it?
+ + aspeed,falling-point: + $ref: /schemas/types.yaml#/definitions/uint8 + default: 10
I feel like it probably shouldn't have a default value.
+ description: + Initialize the pulse width.
Then can we make the property name a bit more intuitive? 'pwm-duty'? Alternatively, [1] calls the duty "cooling-levels", can we use something in that vein instead? [1] Documentation/devicetree/bindings/hwmon/pwm-fan.txt Andrew