[v2 1/3] dt-bindings: Add bindings for aspeed pwm-tach.

[Billy Tsai <billy_tsai@aspeedtech.com>]

On 2022/11/3, 2:19 AM, "Rob Herring" <robh@kernel.org> wrote:

    On Tue, Nov 1, 2022 at 10:21 PM Billy Tsai <billy_tsai@aspeedtech.com> wrote:
    
    > That all sounds like requirements that you have which you should
    > ensure the fan binding can support.

    > I've already said to use the PWM binding in the fan binding exactly
    > for the purpose of hooking up the PWMs to other things. Whether the
    > tach controller is useful for something other than fans, I don't know.
    > Seems less likely. The max6639 also has a tach controller. So if other
    > uses are possible for you, then it could be possible for any other h/w
    > like the max6639.

The linux kernel already have the similar binding:
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/hwmon/pwm-fan.txt 
Therefore, I want to reuse it and the pwm-fan.c instead of creating another similar fan binding and driver.
I am referring to the following files:
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/mfd/kontron%2Csl28cpld.yaml 
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/pwm/kontron%2Csl28cpld-pwm.yaml 
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/hwmon/kontron%2Csl28cpld-hwmon.yaml 
It will also reuse the pwm-fan instead creating it own pwm-fan binding for their hwmon(tach).
https://github.com/torvalds/linux/blob/master/arch/arm64/boot/dts/freescale/fsl-ls1028a-kontron-sl28-var3-ads2.dts#L20 

Thanks

Best Regards,
Billy Tsai