Re: [PATCH v4 1/2] dt-binding: hwmon: Add NPCM7xx PWM and Fan controller documentation

[Rob Herring <robh@kernel.org>]

On Sun, Jun 24, 2018 at 03:41:54PM +0300, Tomer Maimon wrote:
> Added device tree binding documentation for Nuvoton BMC
> NPCM7xx Pulse Width Modulation (PWM)  and Fan tach controller.
> The PWM controller can support upto 8 PWM output ports.
> The Fan tach controller can support upto 16 tachometer inputs.
> 
> Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
> ---
>  .../devicetree/bindings/hwmon/npcm750-pwm-fan.txt  | 84 ++++++++++++++++++++++
>  1 file changed, 84 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt
> new file mode 100644
> index 000000000000..a9eacda34f92
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt
> @@ -0,0 +1,84 @@
> +Nuvoton NPCM7xx PWM and Fan Tacho controller device driver

Bindings are for h/w, not drivers.

> +
> +The NPCM7xx has two identical Pulse-width modulation (PWM) controller modules,
> +Each PWM module has four PWM controller outputs, Totally 8 PWM controller outputs.
> +
> +The NPCM7xx has eight identical Fan tachometer controller modules,
> +Each Fan module has two Fan controller inputs, Totally 16 Fan controller inputs.

Have you looked at other fan ctrlr bindings?f This looks like similar 
h/w to ASpeed. Really, I'd like to see a common doc that describes the 
structure and common properties.

> +
> +Required properties for pwm-fan node:
> +- compatible	: "nuvoton,npcm750-pwm-fan" for Poleg NPCM7XX.
> +- reg 			: specifies physical base address and size of the registers.
> +- reg-names 	: must contain:
> +					* "pwm-base" for the PWM registers.
> + 					* "fan-base" for the Fan registers.

'-base' is redundant. And your example doesn't match.

> +- clocks		: phandle of reference clocks.
> +- clock-names	: must contain
> +					* "clk_apb3" for clock of PWM controller.
> + 					* "clk_apb4" for clock of Fan controller.
> +- interrupts	: contain the Fan interrupts with flags for falling edge.
> +- pinctrl-names	: a pinctrl state named "default" must be defined.
> +- pinctrl-0 	: phandle referencing pin configuration of the PWM and Fan
> +					controller ports.
> +
> +pwm subnode format:
> +===================
> +Under pwm subnode can be upto 8 child nodes, each child node representing a PWM channel.
> +Each pwm subnode must have one PWM channel and atleast one Fan tach channel.
> +
> +For PWM channel can be configured cooling-levels to create cooling device.
> +Cooling device could be bound to a thermal zone for the thermal control.
> +
> +Required properties for each child node:
> +- pwm-ch : specify the PWM output channel.
> +			integer value in the range 0 through 7, that represent
> +			the PWM channel number that used.
> +
> +- fan-ch : specify the Fan input channel.
> +			integer value in the range 0 through 15, that represent
> +			the Fan channel number that used.

This is really the tach channel.


> +
> +			At least one Fan tach input channel is required
> +
> +Optional property for each child node:
> +- cooling-levels: PWM duty cycle values in a range from 0 to 255
> +                  which correspond to thermal cooling states.
> +
> +Examples:
> +
> +pwm_fan:pwm_fan_controller@103000 {

fan-controller@...

> +	compatible = "nuvoton,npcm750-pwm-fan";
> +	reg = <0x103000 0x2000>,
> +		<0x180000 0x8000>;
> +	reg-names = "pwm_base", "fan_base";
> +	clocks = <&clk NPCM7XX_CLK_APB3>,
> +		<&clk NPCM7XX_CLK_APB4>;
> +	clock-names = "clk_apb3","clk_apb4";
> +	interrupts = <GIC_SPI 96 IRQ_TYPE_LEVEL_HIGH>,
> +			<GIC_SPI 97 IRQ_TYPE_LEVEL_HIGH>,
> +			<GIC_SPI 98 IRQ_TYPE_LEVEL_HIGH>,
> +			<GIC_SPI 99 IRQ_TYPE_LEVEL_HIGH>,
> +			<GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>,
> +			<GIC_SPI 101 IRQ_TYPE_LEVEL_HIGH>,
> +			<GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>,
> +			<GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&pwm0_pins &pwm1_pins &pwm2_pins
> +			&fanin0_pins &fanin1_pins &fanin2_pins
> +			&fanin3_pins &fanin4_pins>;
> +
> +			pwm@0 {

The sub-nodes should be "fan" nodes.

A unit-address without reg property is not valid.

> +				pwm-ch = /bits/ 8 <0x00>;

Use 'reg' like ASpeed binding. 

> +				fan-ch = /bits/ 8 <0x00 0x01>;
> +				cooling-levels = <127 255>;
> +				};
> +			pwm@1 {
> +				pwm-ch = /bits/ 8 <0x01>;
> +				fan-ch = /bits/ 8 <0x02 0x03>;
> +				};
> +			pwm@2 {
> +				pwm-ch = /bits/ 8 <0x02>;
> +				fan-ch = /bits/ 8 <0x04>;
> +				};
> +
> +};
> \ No newline at end of file

^^^

> -- 
> 2.14.1
> 
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