dt-binding: hwmon: Add NPCM7xx PWM and Fan controller documentation

Added device tree binding documentation for Nuvoton BMC
NPCM7xx Pulse Width Modulation (PWM)  and Fan tach controller.
The Nuvoton BMC NPCM7XX supports 8 PWM controller outputs
and 16 Fan tachometer controller inputs.

Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
[groeck: Fixed whitespace errors noticed by git]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt
new file mode 100644 (file)
index 0000000..28f43e9
--- /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>;
+       };
+
+};