[PATCH v2 1/1] arm64: dts: ti: k3-am62-wakeup: Configure ti-sysc for wkup_uart0

[Kevin Hilman]

Tony Lindgren <tony at atomide.com> writes:

> * Kevin Hilman <khilman at kernel.org> [231205 18:14]:
>> I'm a little confused why these power-domain and clocks stay here and
>> are not moved under the wkup_uart0 node... 
>
> The resources are also needed by the interconnect target module. It's the
> wrapper IP for the child device(s). In this case there's one chip 8250 IP
> instance. In some other devices there can be multiple child IP devices
> wired to one target module.
>
>> > -		clock-names = "fclk";
>> > -		status = "disabled";
>> > +		clock-names = "fck";
>> > +		#address-cells = <1>;
>> > +		#size-cells = <1>;
>> > +		ranges = <0 0 0x2b300000 0x100000>;
>> > +
>> > +		wkup_uart0: serial at 2b300000 {
>> > +			compatible = "ti,am64-uart", "ti,am654-uart";
>> > +			reg = <0 0x100>;
>> > +			interrupts = <GIC_SPI 186 IRQ_TYPE_LEVEL_HIGH>;
>> > +			status = "disabled";
>> 
>> ...here.
>> 
>> The SCI device ID 114 is specifically for wkup_uart0[1], so it seems to
>> me those should be in the wkup_uart0 node.
>
> Those resources are also needed for the parent target module for revision
> detection, quirks, reset, idle register configuration, and to probe the
> child devices.
>
> Here the 8250 IP can be set to status = "reserved" when used by the
> firmware, and 8250 not touched by Linux. However, the parent interconnect
> target module still needs to be configured for idle registers and wake-up
> path register bit so the wake-up from deeper suspend states works.

OK, makes sense.  Thanks for the clarification.

In that case, shouldn't the same be done for the other wakeup sources
there (e.g. wkup_rtc0) ?

Kevin