xref: /freebsd/sys/contrib/device-tree/Bindings/hwmon/npcm750-pwm-fan.txt (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0) 
1Nuvoton NPCM 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
6The Nuvoton BMC NPCM8XX supports 12 Pulse-width modulation (PWM)
7controller outputs and 16 Fan tachometer controller inputs.
8
9Required properties for pwm-fan node
10- #address-cells : should be 1.
11- #size-cells	: should be 0.
12- compatible	: "nuvoton,npcm750-pwm-fan" for Poleg NPCM7XX.
13				: "nuvoton,npcm845-pwm-fan" for Arbel NPCM8XX.
14- reg			: specifies physical base address and size of the registers.
15- reg-names	: must contain:
16					* "pwm" for the PWM registers.
17					* "fan" for the Fan registers.
18- clocks		: phandle of reference clocks.
19- clock-names	: must contain
20					* "pwm" for PWM controller operating clock.
21					* "fan" for Fan controller operating clock.
22- interrupts	: contain the Fan interrupts with flags for falling edge.
23- pinctrl-names	: a pinctrl state named "default" must be defined.
24- pinctrl-0	: phandle referencing pin configuration of the PWM and Fan
25					controller ports.
26
27fan subnode format:
28===================
29Under fan subnode can be upto 8 child nodes, each child node representing a fan.
30Each fan subnode must have one PWM channel and at least one Fan tach channel.
31
32For PWM channel can be configured cooling-levels to create cooling device.
33Cooling device could be bound to a thermal zone for the thermal control.
34
35Required properties for each child node:
36- reg : specify the PWM output channel.
37	integer value in the range 0 through 7, that represent
38	the PWM channel number that used.
39
40- fan-tach-ch : specify the Fan tach input channel.
41		integer value in the range 0 through 15, that represent
42		the fan tach channel number that used.
43
44		At least one Fan tach input channel is required
45
46Optional property for each child node:
47- cooling-levels: PWM duty cycle values in a range from 0 to 255
48                  which correspond to thermal cooling states.
49
50Examples:
51
52pwm_fan:pwm-fan-controller@103000 {
53	#address-cells = <1>;
54	#size-cells = <0>;
55	compatible = "nuvoton,npcm750-pwm-fan";
56	reg = <0x103000 0x2000>,
57		<0x180000 0x8000>;
58	reg-names = "pwm", "fan";
59	clocks = <&clk NPCM7XX_CLK_APB3>,
60		<&clk NPCM7XX_CLK_APB4>;
61	clock-names = "pwm","fan";
62	interrupts = <GIC_SPI 96 IRQ_TYPE_LEVEL_HIGH>,
63			<GIC_SPI 97 IRQ_TYPE_LEVEL_HIGH>,
64			<GIC_SPI 98 IRQ_TYPE_LEVEL_HIGH>,
65			<GIC_SPI 99 IRQ_TYPE_LEVEL_HIGH>,
66			<GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>,
67			<GIC_SPI 101 IRQ_TYPE_LEVEL_HIGH>,
68			<GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>,
69			<GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
70	pinctrl-names = "default";
71	pinctrl-0 = <&pwm0_pins &pwm1_pins &pwm2_pins
72			&fanin0_pins &fanin1_pins &fanin2_pins
73			&fanin3_pins &fanin4_pins>;
74	fan@0 {
75		reg = <0x00>;
76		fan-tach-ch = /bits/ 8 <0x00 0x01>;
77		cooling-levels = <127 255>;
78	};
79	fan@1 {
80		reg = <0x01>;
81		fan-tach-ch = /bits/ 8 <0x02 0x03>;
82	};
83	fan@2 {
84		reg = <0x02>;
85		fan-tach-ch = /bits/ 8 <0x04>;
86	};
87
88};
89