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Diffstat (limited to 'Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt')
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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..28f43e929f6d --- /dev/null +++ b/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt @@ -0,0 +1,84 @@ +Nuvoton NPCM7xx PWM and Fan Tacho controller device + +The Nuvoton BMC NPCM7XX supports 8 Pulse-width modulation (PWM) +controller outputs and 16 Fan tachometer controller inputs. + +Required properties for pwm-fan node +- #address-cells : should be 1. +- #size-cells : should be 0. +- compatible : "nuvoton,npcm750-pwm-fan" for Poleg NPCM7XX. +- reg : specifies physical base address and size of the registers. +- reg-names : must contain: + * "pwm" for the PWM registers. + * "fan" for the Fan registers. +- clocks : phandle of reference clocks. +- clock-names : must contain + * "pwm" for PWM controller operating clock. + * "fan" for Fan controller operating clock. +- 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. + +fan subnode format: +=================== +Under fan subnode can be upto 8 child nodes, each child node representing a fan. +Each fan 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: +- reg : specify the PWM output channel. + integer value in the range 0 through 7, that represent + the PWM channel number that used. + +- fan-tach-ch : specify the Fan tach input channel. + integer value in the range 0 through 15, that represent + the fan tach channel number that used. + + 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 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "nuvoton,npcm750-pwm-fan"; + reg = <0x103000 0x2000>, + <0x180000 0x8000>; + reg-names = "pwm", "fan"; + clocks = <&clk NPCM7XX_CLK_APB3>, + <&clk NPCM7XX_CLK_APB4>; + clock-names = "pwm","fan"; + 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>; + fan@0 { + reg = <0x00>; + fan-tach-ch = /bits/ 8 <0x00 0x01>; + cooling-levels = <127 255>; + }; + fan@1 { + reg = <0x01>; + fan-tach-ch = /bits/ 8 <0x02 0x03>; + }; + fan@2 { + reg = <0x02>; + fan-tach-ch = /bits/ 8 <0x04>; + }; + +}; |