xref: /linux/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt (revision 24bce201d79807b668bf9d9e0aca801c5c0d5f78)
1Nuvoton NPCM7xx PWM and Fan Tacho controller device
2
3The Nuvoton BMC NPCM7XX supports 8 Pulse-width modulation (PWM)
4controller outputs and 16 Fan tachometer controller inputs.
5
6Required properties for pwm-fan node
7- #address-cells : should be 1.
8- #size-cells	: should be 0.
9- compatible	: "nuvoton,npcm750-pwm-fan" for Poleg NPCM7XX.
10- reg			: specifies physical base address and size of the registers.
11- reg-names	: must contain:
12					* "pwm" for the PWM registers.
13					* "fan" for the Fan registers.
14- clocks		: phandle of reference clocks.
15- clock-names	: must contain
16					* "pwm" for PWM controller operating clock.
17					* "fan" for Fan controller operating clock.
18- interrupts	: contain the Fan interrupts with flags for falling edge.
19- pinctrl-names	: a pinctrl state named "default" must be defined.
20- pinctrl-0	: phandle referencing pin configuration of the PWM and Fan
21					controller ports.
22
23fan subnode format:
24===================
25Under fan subnode can be upto 8 child nodes, each child node representing a fan.
26Each fan subnode must have one PWM channel and atleast one Fan tach channel.
27
28For PWM channel can be configured cooling-levels to create cooling device.
29Cooling device could be bound to a thermal zone for the thermal control.
30
31Required properties for each child node:
32- reg : specify the PWM output channel.
33	integer value in the range 0 through 7, that represent
34	the PWM channel number that used.
35
36- fan-tach-ch : specify the Fan tach input channel.
37		integer value in the range 0 through 15, that represent
38		the fan tach channel number that used.
39
40		At least one Fan tach input channel is required
41
42Optional property for each child node:
43- cooling-levels: PWM duty cycle values in a range from 0 to 255
44                  which correspond to thermal cooling states.
45
46Examples:
47
48pwm_fan:pwm-fan-controller@103000 {
49	#address-cells = <1>;
50	#size-cells = <0>;
51	compatible = "nuvoton,npcm750-pwm-fan";
52	reg = <0x103000 0x2000>,
53		<0x180000 0x8000>;
54	reg-names = "pwm", "fan";
55	clocks = <&clk NPCM7XX_CLK_APB3>,
56		<&clk NPCM7XX_CLK_APB4>;
57	clock-names = "pwm","fan";
58	interrupts = <GIC_SPI 96 IRQ_TYPE_LEVEL_HIGH>,
59			<GIC_SPI 97 IRQ_TYPE_LEVEL_HIGH>,
60			<GIC_SPI 98 IRQ_TYPE_LEVEL_HIGH>,
61			<GIC_SPI 99 IRQ_TYPE_LEVEL_HIGH>,
62			<GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>,
63			<GIC_SPI 101 IRQ_TYPE_LEVEL_HIGH>,
64			<GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>,
65			<GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
66	pinctrl-names = "default";
67	pinctrl-0 = <&pwm0_pins &pwm1_pins &pwm2_pins
68			&fanin0_pins &fanin1_pins &fanin2_pins
69			&fanin3_pins &fanin4_pins>;
70	fan@0 {
71		reg = <0x00>;
72		fan-tach-ch = /bits/ 8 <0x00 0x01>;
73		cooling-levels = <127 255>;
74	};
75	fan@1 {
76		reg = <0x01>;
77		fan-tach-ch = /bits/ 8 <0x02 0x03>;
78	};
79	fan@2 {
80		reg = <0x02>;
81		fan-tach-ch = /bits/ 8 <0x04>;
82	};
83
84};
85