Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt

   1 Nuvoton NPCM7xx PWM and Fan Tacho controller device
   2
   3 The Nuvoton BMC NPCM7XX supports 8 Pulse-width modulation (PWM)
   4 controller outputs and 16 Fan tachometer controller inputs.
   5
   6 Required 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
  23 fan subnode format:
  24 ===================
  25 Under fan subnode can be upto 8 child nodes, each child node representing a fan.
  26 Each fan subnode must have one PWM channel and atleast one Fan tach channel.
  27
  28 For PWM channel can be configured cooling-levels to create cooling device.
  29 Cooling device could be bound to a thermal zone for the thermal control.
  30
  31 Required 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
  42 Optional 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
  46 Examples:
  47
  48 pwm_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 };