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8c9e527057
The device tree bindings are updated to document the resets phandle, and the example is updated to match what is expected for both the reset and clock phandle. Note that the bindings should have always had the reset controller, as the hardware is unusable without it. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
73 lines
2.3 KiB
Text
73 lines
2.3 KiB
Text
ASPEED AST2400/AST2500 PWM and Fan Tacho controller device driver
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The ASPEED PWM controller can support upto 8 PWM outputs. The ASPEED Fan Tacho
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controller can support upto 16 Fan tachometer inputs.
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There can be upto 8 fans supported. Each fan can have one PWM output and
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one/two Fan tach inputs.
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Required properties for pwm-tacho node:
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- #address-cells : should be 1.
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- #size-cells : should be 1.
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- #cooling-cells: should be 2.
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- reg : address and length of the register set for the device.
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- pinctrl-names : a pinctrl state named "default" must be defined.
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- pinctrl-0 : phandle referencing pin configuration of the PWM ports.
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- compatible : should be "aspeed,ast2400-pwm-tacho" for AST2400 and
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"aspeed,ast2500-pwm-tacho" for AST2500.
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- clocks : phandle to clock provider with the clock number in the second cell
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- resets : phandle to reset controller with the reset number in the second cell
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fan subnode format:
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===================
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Under fan subnode there can upto 8 child nodes, with each child node
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representing a fan. If there are 8 fans each fan can have one PWM port and
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one/two Fan tach inputs.
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For PWM port can be configured cooling-levels to create cooling device.
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Cooling device could be bound to a thermal zone for the thermal control.
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Required properties for each child node:
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- reg : should specify PWM source port.
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integer value in the range 0 to 7 with 0 indicating PWM port A and
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7 indicating PWM port H.
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- cooling-levels: PWM duty cycle values in a range from 0 to 255
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which correspond to thermal cooling states.
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- aspeed,fan-tach-ch : should specify the Fan tach input channel.
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integer value in the range 0 through 15, with 0 indicating
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Fan tach channel 0 and 15 indicating Fan tach channel 15.
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Atleast one Fan tach input channel is required.
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Examples:
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pwm_tacho: pwmtachocontroller@1e786000 {
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#address-cells = <1>;
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#size-cells = <1>;
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#cooling-cells = <2>;
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reg = <0x1E786000 0x1000>;
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compatible = "aspeed,ast2500-pwm-tacho";
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clocks = <&syscon ASPEED_CLK_APB>;
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resets = <&syscon ASPEED_RESET_PWM>;
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pinctrl-names = "default";
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pinctrl-0 = <&pinctrl_pwm0_default &pinctrl_pwm1_default>;
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fan@0 {
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reg = <0x00>;
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cooling-levels = /bits/ 8 <125 151 177 203 229 255>;
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aspeed,fan-tach-ch = /bits/ 8 <0x00>;
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};
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fan@1 {
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reg = <0x01>;
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aspeed,fan-tach-ch = /bits/ 8 <0x01 0x02>;
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};
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};
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