Re: [PATCH 3/3] arm64: boot: dts: ti: k3-am62l3-evm: enable WKUP UART wakeup from LPM

Kendall Willis
2026-01-05T22:14:39Z

On 1/5/26 08:01, Bryan Brattlof wrote:
> On December 30, 2025 thus sayeth Kendall Willis:
>> Change the status of the wkup_uart0_interconnect node to enabled. The
>> target-module node sets the UART SYSC and SYSS registers to allow wakeup
>> from WKUP UART in DeepSleep low power mode.
>>
>> Signed-off-by: Kendall Willis <k-willis@ti.com>
>> ---
>> arch/arm64/boot/dts/ti/k3-am62l3-evm.dts | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/ti/k3-am62l3-evm.dts b/arch/arm64/boot/dts/ti/k3-am62l3-evm.dts
>> index cae04cce337366b50928d39b0c888550b14e43d3..02b1a1c76b2ee05d49cd69d199a6aacdb1973fa0 100644
>> --- a/arch/arm64/boot/dts/ti/k3-am62l3-evm.dts
>> +++ b/arch/arm64/boot/dts/ti/k3-am62l3-evm.dts
>> @@ -359,3 +359,7 @@ &usb1 {
>> pinctrl-names = "default";
>> pinctrl-0 = <&usb1_default_pins>;
>> };
>> +
>> +&wkup_uart0_interconnect {
>> + status = "okay";
>> +};
>
> Does the UART need to be enabled as well?
>
> ~Bryan

The UART does not need to be enabled because the interconnect target
module manages the SYSC register which configures the WKUP_UART to be
able to wakeup the SoC from system suspend. This allows the WKUP_UART to
be wakeup capable for the SoC even if it is disabled by Linux.

Best,
Kendall