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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};