Re: DT overlay syntax question

Thank you, I'll have a close look at this.

On 20/07/2025 15:00, Robert Swindells wrote:
> Vincent DEFERT <[email protected]> wrote:
>> I'm trying to create overlays for optional functionalities on my ODROID C2.
>> It works well for I2C and UART, but not for PWM, I get a syntax error
>> when defining clocks.
>>
>> The overlay source is:
>>
>> /dts-v1/;
>> /plugin/;
>>
>> / {
>>       /*
>>        * Enable PWM A.
>>        * Uses GPIOX.BIT6 on GPIO connector pin 33.
>>        */
>>       pwm_ab {
>>           status = "okay";
>>           pinctrl-0 = <&pwm_a_x_pins>;
>>           pinctrl-names = "default";
>>           clocks = <&xtal>, <&clkc CLKID_VID_PLL>, <&clkc
>> CLKID_FCLK_DIV4>, <&clkc CLKID_FCLK_DIV3>;
>>           clock-names = "xtal", "vid_pll", "fclk_div4", "fclk_div3";
>>       };
>> };
> I don't think that is what you want to have in the device tree for
> clocks.
>
> Other nodes that define clocks are doing that because they all need
> to be enabled for the device to work, our clock controller driver then
> takes care of how the clock tree needs to be setup for this to happen,
> you just want to pick one of them for the input to the pwm device.
>
> Other uses of overlays are for specific tasks, I think I would expect an
> overlay that setup a PWM device to define which clock it wants to use.
>
> There also isn't a definition for VID_PLL in mesongxbb_clkc.[ch] yet, if
> that is the clock you need, I'm guessing that the meson clock code
> didn't get updated when we last did a device tree source update.