On 6/7/23 23:21, Billy Tsai wrote:
> The code says:
> In Aspeed AST2600 SoC features 16 TACH controllers, with each
> controller capable of supporting up to 1 input.
> which is a bit different. I guess there are no examples anymore,
> but I'd really like to see how this looks like in the devicetree file,
> and how the driver is supposed to distinguish/select the 16 inputs.
Hi Roeck,
The node in the devicetree file will looks like following:
tach0: tach0@1e610008 {
compatible = "aspeed,ast2600-tach";
reg = <0x1e610008 0x8>;
#address-cells = <1>;
#size-cells = <0>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_tach0_default>;
clocks = <&syscon ASPEED_CLK_AHB>;
resets = <&syscon ASPEED_RESET_PWM>;
status = "disabled";
};
Neither reg nor pinctrl is mentioned in the bindings. Maybe that is not needed nowadays,
but I find it confusing.
Either case, it is highly unusual that there would be 16 instances of this device
instead of one. Why is this done ? It doesn't really make sense to me.
Guenter
