Re: [PATCH v12 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control

From: Billy Tsai
Date: Mon Jan 15 2024 - 03:43:26 EST


> >>> +examples:
> >>> + - |
> >>> + #include <dt-bindings/clock/aspeed-clock.h>
> >>> + pwm_tach: pwm-tach-controller@1e610000 {
> >>> + compatible = "aspeed,ast2600-pwm-tach";
> >>> + reg = <0x1e610000 0x100>;
> >>> + clocks = <&syscon ASPEED_CLK_AHB>;
> >>> + resets = <&syscon ASPEED_RESET_PWM>;
> >>> + #pwm-cells = <3>;
> >>> +
> >>> + fan-0 {
> >>> + tach-ch = /bits/ 8 <0x0>;
> >>> + };
> >>> +
> >>> + fan-1 {
> >>> + tach-ch = /bits/ 8 <0x1 0x2>;
> >>> + };
> >
> >> NAK on this based on how you are using pwm-fan in v10 discussion. See my
> >> comments there.
> >
> > Okay, I will merge everything from the pwm-fan0 node into the fan-0 node
> > and add the 'simple-bus' to the compatible string of the pwm_tach node.

> What simple-bus has anything to do with it? This is not a bus. Just to
> remind: we talk about bindings, not driver.

Hi Krzysztof,

If I want to create a dt-binding to indicate that the child nodes
should be treated as platform devices, which will be probed based on the
compatible string, can I add "simple-bus" for our pwm_tach node like the
following?
pwm_tach: pwm-tach-controller@1e610000 {
compatible = "aspeed,ast2600-pwm-tach", "simple-bus";
reg = <0x1e610000 0x100>;
clocks = <&syscon ASPEED_CLK_AHB>;
resets = <&syscon ASPEED_RESET_PWM>;
#pwm-cells = <3>;

fan-0 {
tach-ch = /bits/ 8 <0x0>;
compatible = "pwm-fan";
pwms = <&pwm_tach 0 40000 0>;
};

fan-1 {
tach-ch = /bits/ 8 <0x1 0x2>;
compatible = "pwm-fan";
pwms = <&pwm_tach 1 40000 0>;
};
};
Or do you have any other suggestions for describing this in the dt-bindings?

Thanks

Billy Tsai.