From d702b353b9d3fccbeabba96ed530ffc87f303465 Mon Sep 17 00:00:00 2001 From: Jaghathiswari Rankappagounder Natarajan Date: Tue, 4 Apr 2017 17:52:40 -0700 Subject: [PATCH] Documentation: dt-bindings: Document bindings for ASPEED AST2400/AST2500 PWM and Fan tach controller device driver This binding provides interface for adding values related to ASPEED AST2400/2500 PWM and Fan tach controller support. The PWM controller can support upto 8 PWM output ports. The Fan tach controller can support upto 16 tachometer inputs. Signed-off-by: Jaghathiswari Rankappagounder Natarajan Acked-by: Rob Herring Signed-off-by: Guenter Roeck --- .../devicetree/bindings/hwmon/aspeed-pwm-tacho.txt | 68 ++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt diff --git a/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt b/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt new file mode 100644 index 0000000..cf44605 --- /dev/null +++ b/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt @@ -0,0 +1,68 @@ +ASPEED AST2400/AST2500 PWM and Fan Tacho controller device driver + +The ASPEED PWM controller can support upto 8 PWM outputs. The ASPEED Fan Tacho +controller can support upto 16 Fan tachometer inputs. + +There can be upto 8 fans supported. Each fan can have one PWM output and +one/two Fan tach inputs. + +Required properties for pwm-tacho node: +- #address-cells : should be 1. + +- #size-cells : should be 1. + +- reg : address and length of the register set for the device. + +- pinctrl-names : a pinctrl state named "default" must be defined. + +- pinctrl-0 : phandle referencing pin configuration of the PWM ports. + +- compatible : should be "aspeed,ast2400-pwm-tacho" for AST2400 and + "aspeed,ast2500-pwm-tacho" for AST2500. + +- clocks : a fixed clock providing input clock frequency(PWM + and Fan Tach clock) + +fan subnode format: +=================== +Under fan subnode there can upto 8 child nodes, with each child node +representing a fan. If there are 8 fans each fan can have one PWM port and +one/two Fan tach inputs. + +Required properties for each child node: +- reg : should specify PWM source port. + integer value in the range 0 to 7 with 0 indicating PWM port A and + 7 indicating PWM port H. + +- aspeed,fan-tach-ch : should specify the Fan tach input channel. + integer value in the range 0 through 15, with 0 indicating + Fan tach channel 0 and 15 indicating Fan tach channel 15. + Atleast one Fan tach input channel is required. + +Examples: + +pwm_tacho_fixed_clk: fixedclk { + compatible = "fixed-clock"; + #clock-cells = <0>; + clock-frequency = <24000000>; +}; + +pwm_tacho: pwmtachocontroller@1e786000 { + #address-cells = <1>; + #size-cells = <1>; + reg = <0x1E786000 0x1000>; + compatible = "aspeed,ast2500-pwm-tacho"; + clocks = <&pwm_tacho_fixed_clk>; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_pwm0_default &pinctrl_pwm1_default>; + + fan@0 { + reg = <0x00>; + aspeed,fan-tach-ch = /bits/ 8 <0x00>; + }; + + fan@1 { + reg = <0x01>; + aspeed,fan-tach-ch = /bits/ 8 <0x01 0x02>; + }; +}; -- 2.7.4