[PATCH 0/3] arm64: boot: dts: ti: k3-am62l: enable WKUP UART wakeup

[PATCH 0/3] arm64: boot: dts: ti: k3-am62l: enable WKUP UART wakeup

[Kendall Willis]

K3 TI AM62L SoC supports wakeup from WKUP UART when the SoC is in the
DeepSleep low power mode. To enable WKUP UART the target-module device
tree node is enabled. The ti-sysc interconnect target module driver is
used to configure the the SYSCONFIG related registers to allow wakeup
from WKUP UART when the system is suspended. Refer to 14.7.2.5 UART in the
AM62L Techincal Reference Manual for registers referenced [1].

Previous TI SoCs configure the WKUP UART to wakeup from system suspend
using the ti-sysc interconnect target module driver. Refer to commit
ce27f7f9e328 ("arm64: dts: ti: k3-am62-wakeup: Configure ti-sysc for
wkup_uart0") for an example of this.

Testing
-------
Tested on AM62L EVM on v6.19-rc3. Suspend/resume verified with the WKUP
UART wakeup source by entering a keypress on the console. 

[1] https://www.ti.com/lit/ug/sprujb4a/sprujb4a.pdf

Signed-off-by: Kendall Willis <k-willis@ti.com>
---
Kendall Willis (3):
      arm64: dts: ti: k3-am62l: include WKUP_UART0 in wakeup peripheral window
      arm64: boot: dts: ti: k3-am62l-wakeup: create label for target-module
      arm64: boot: dts: ti: k3-am62l3-evm: enable WKUP UART wakeup from LPM

 arch/arm64/boot/dts/ti/k3-am62l-wakeup.dtsi | 2 +-
 arch/arm64/boot/dts/ti/k3-am62l.dtsi        | 4 ++--
 arch/arm64/boot/dts/ti/k3-am62l3-evm.dts    | 4 ++++
 3 files changed, 7 insertions(+), 3 deletions(-)
---
base-commit: 5dc233097d4f94776c0c3f6edfd7476281478dc3
change-id: 20251230-wkup-uart-wakeup-8bbc95aa8f8e

Best regards,
-- 
Kendall Willis <k-willis@ti.com>

[PATCH 1/3] arm64: dts: ti: k3-am62l: include WKUP_UART0 in wakeup peripheral window

[Kendall Willis]

WKUP_UART0 is apart of the wakeup peripherals and has a range from
0x002B300000 to 0x002B3001FF. Expand the wakeup peripheral window to
include WKUP_UART0.

Fixes: 5f016758b0ab ("arm64: dts: ti: k3-am62l: add initial infrastructure")
Signed-off-by: Kendall Willis <k-willis@ti.com>
---
 arch/arm64/boot/dts/ti/k3-am62l.dtsi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/ti/k3-am62l.dtsi b/arch/arm64/boot/dts/ti/k3-am62l.dtsi
index 23acdbb301fe38e6045c0ef3ae340196009ed217..e01e342c26daaa06a72036cc3a9a7b13a60e6738 100644
--- a/arch/arm64/boot/dts/ti/k3-am62l.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am62l.dtsi
@@ -92,7 +92,7 @@ cbass_main: bus@f0000 {
 			 <0x00 0x00b00000 0x00 0x00b00000 0x00 0x00001400>, /* VTM */
 			 <0x00 0x04080000 0x00 0x04080000 0x00 0x00008000>, /* PDCFG */
 			 <0x00 0x04201000 0x00 0x04201000 0x00 0x00000100>, /* GPIO */
-			 <0x00 0x2b100000 0x00 0x2b100000 0x00 0x00100100>, /* Wakeup Peripheral Window */
+			 <0x00 0x2b100000 0x00 0x2b100000 0x00 0x00200200>, /* Wakeup Peripheral Window */
 			 <0x00 0x40800000 0x00 0x40800000 0x00 0x00014000>, /* DMA */
 			 <0x00 0x43000000 0x00 0x43000000 0x00 0x00080000>; /* CTRL MMRs */
 		#address-cells = <2>;
@@ -104,7 +104,7 @@ cbass_wakeup: bus@a80000 {
 				 <0x00 0x00b00000 0x00 0x00b00000 0x00 0x00001400>, /* VTM */
 				 <0x00 0x04080000 0x00 0x04080000 0x00 0x00008000>, /* PDCFG */
 				 <0x00 0x04201000 0x00 0x04201000 0x00 0x00000100>, /* GPIO */
-				 <0x00 0x2b100000 0x00 0x2b100000 0x00 0x00100100>, /* Wakeup Peripheral Window */
+				 <0x00 0x2b100000 0x00 0x2b100000 0x00 0x00200200>, /* Wakeup Peripheral Window */
 				 <0x00 0x40800000 0x00 0x40800000 0x00 0x00014000>, /* DMA */
 				 <0x00 0x43000000 0x00 0x43000000 0x00 0x00080000>; /* CTRL MMRs */
 			#address-cells = <2>;

-- 
2.34.1

[PATCH 2/3] arm64: boot: dts: ti: k3-am62l-wakeup: create label for target-module

[Kendall Willis]

Add label to the target-module node so that it can easily be referenced.
The node specifically configures the SYSCONFIG related registers for WKUP
UART.

Signed-off-by: Kendall Willis <k-willis@ti.com>
---
 arch/arm64/boot/dts/ti/k3-am62l-wakeup.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/ti/k3-am62l-wakeup.dtsi b/arch/arm64/boot/dts/ti/k3-am62l-wakeup.dtsi
index 61bfcdcfc66ea8d802a36ed43cd01fbbf3decc70..e9d638d9ffd3a52aa6e0df70f6003879bc292358 100644
--- a/arch/arm64/boot/dts/ti/k3-am62l-wakeup.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am62l-wakeup.dtsi
@@ -81,7 +81,7 @@ wkup_i2c0: i2c@2b200000 {
 		status = "disabled";
 	};
 
-	target-module@2b300050 {
+	wkup_uart0_interconnect: target-module@2b300050 {
 		compatible = "ti,sysc-omap2", "ti,sysc";
 		reg = <0x00 0x2b300050 0x00 0x4>,
 		      <0x00 0x2b300054 0x00 0x4>,

-- 
2.34.1

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

[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";
+};

-- 
2.34.1

Re: [PATCH 1/3] arm64: dts: ti: k3-am62l: include WKUP_UART0 in wakeup peripheral window

[Dhruva Gole]

On Dec 30, 2025 at 20:51:40 -0600, Kendall Willis wrote:
> WKUP_UART0 is apart of the wakeup peripherals and has a range from

Nit: a _space_ part

> 0x002B300000 to 0x002B3001FF. Expand the wakeup peripheral window to
> include WKUP_UART0.
> 
> Fixes: 5f016758b0ab ("arm64: dts: ti: k3-am62l: add initial infrastructure")
> Signed-off-by: Kendall Willis <k-willis@ti.com>
> ---
>  arch/arm64/boot/dts/ti/k3-am62l.dtsi | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/ti/k3-am62l.dtsi b/arch/arm64/boot/dts/ti/k3-am62l.dtsi
> index 23acdbb301fe38e6045c0ef3ae340196009ed217..e01e342c26daaa06a72036cc3a9a7b13a60e6738 100644
> --- a/arch/arm64/boot/dts/ti/k3-am62l.dtsi
> +++ b/arch/arm64/boot/dts/ti/k3-am62l.dtsi
> @@ -92,7 +92,7 @@ cbass_main: bus@f0000 {
>  			 <0x00 0x00b00000 0x00 0x00b00000 0x00 0x00001400>, /* VTM */
>  			 <0x00 0x04080000 0x00 0x04080000 0x00 0x00008000>, /* PDCFG */
>  			 <0x00 0x04201000 0x00 0x04201000 0x00 0x00000100>, /* GPIO */
> -			 <0x00 0x2b100000 0x00 0x2b100000 0x00 0x00100100>, /* Wakeup Peripheral Window */
> +			 <0x00 0x2b100000 0x00 0x2b100000 0x00 0x00200200>, /* Wakeup Peripheral Window */
>  			 <0x00 0x40800000 0x00 0x40800000 0x00 0x00014000>, /* DMA */
>  			 <0x00 0x43000000 0x00 0x43000000 0x00 0x00080000>; /* CTRL MMRs */
>  		#address-cells = <2>;
> @@ -104,7 +104,7 @@ cbass_wakeup: bus@a80000 {
 
Reviewed-by: Dhruva Gole <d-gole@ti.com>

-- 
Best regards,
Dhruva Gole
Texas Instruments Incorporated

Re: [PATCH 2/3] arm64: boot: dts: ti: k3-am62l-wakeup: create label for target-module

[Dhruva Gole]

On Dec 30, 2025 at 20:51:41 -0600, Kendall Willis wrote:
> Add label to the target-module node so that it can easily be referenced.
> The node specifically configures the SYSCONFIG related registers for WKUP
> UART.
> 
> Signed-off-by: Kendall Willis <k-willis@ti.com>
> ---
>  arch/arm64/boot/dts/ti/k3-am62l-wakeup.dtsi | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/ti/k3-am62l-wakeup.dtsi b/arch/arm64/boot/dts/ti/k3-am62l-wakeup.dtsi
> index 61bfcdcfc66ea8d802a36ed43cd01fbbf3decc70..e9d638d9ffd3a52aa6e0df70f6003879bc292358 100644
> --- a/arch/arm64/boot/dts/ti/k3-am62l-wakeup.dtsi
> +++ b/arch/arm64/boot/dts/ti/k3-am62l-wakeup.dtsi
> @@ -81,7 +81,7 @@ wkup_i2c0: i2c@2b200000 {
>  		status = "disabled";
>  	};
>  
> -	target-module@2b300050 {
> +	wkup_uart0_interconnect: target-module@2b300050 {

Reviewed-by: Dhruva Gole <d-gole@ti.com>

-- 
Best regards,
Dhruva Gole
Texas Instruments Incorporated

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

[Dhruva Gole]

On Dec 30, 2025 at 20:51:42 -0600, Kendall Willis wrote:
> 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";
> +};

Reviewed-by: Dhruva Gole <d-gole@ti.com>

> 
> -- 
> 2.34.1
> 

-- 
Best regards,
Dhruva Gole
Texas Instruments Incorporated

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

[Nishanth Menon]

On 20:51-20251230, Kendall Willis wrote:
> 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";
> +};

don't we need to set status okay and provide pinmux for wkup_uart?

> 
> -- 
> 2.34.1
> 

-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D
https://ti.com/opensource

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

[Bryan Brattlof]

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

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

[Kendall Willis]

On 1/5/26 07:55, Nishanth Menon wrote:
> On 20:51-20251230, Kendall Willis wrote:
>> 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";
>> +};
> 
> don't we need to set status okay and provide pinmux for wkup_uart?
> 

No, only the interconnect target node needs to be enabled because it 
manages the SYSC register. The SYSC register configures the WKUP_UART to 
be able to wakeup the SoC from system suspend. This allows the WKUP_UART 
to be wakeup capable even if it is reserved by firmware.

Best,
Kendall

>>
>> -- 
>> 2.34.1
>>
> 

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

[Kendall Willis]

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

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

[Nishanth Menon]

On 16:10-20260105, Kendall Willis wrote:
> On 1/5/26 07:55, Nishanth Menon wrote:
> > On 20:51-20251230, Kendall Willis wrote:
> > > 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";
> > > +};
> > 
> > don't we need to set status okay and provide pinmux for wkup_uart?
> > 
> 
> No, only the interconnect target node needs to be enabled because it manages
> the SYSC register. The SYSC register configures the WKUP_UART to be able to
> wakeup the SoC from system suspend. This allows the WKUP_UART to be wakeup
> capable even if it is reserved by firmware.
> 

If wkup_uart is controlled by firmware, it should be managed by
firmware. $subject claims that wkup_uart is being enabled, but it is
not.


-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D
https://ti.com/opensource

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

[Kendall Willis]

On 1/6/26 05:56, Nishanth Menon wrote:
> On 16:10-20260105, Kendall Willis wrote:
>> On 1/5/26 07:55, Nishanth Menon wrote:
>>> On 20:51-20251230, Kendall Willis wrote:
>>>> 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";
>>>> +};
>>>
>>> don't we need to set status okay and provide pinmux for wkup_uart?
>>>
>>
>> No, only the interconnect target node needs to be enabled because it manages
>> the SYSC register. The SYSC register configures the WKUP_UART to be able to
>> wakeup the SoC from system suspend. This allows the WKUP_UART to be wakeup
>> capable even if it is reserved by firmware.
>>
> 
> If wkup_uart is controlled by firmware, it should be managed by
> firmware. $subject claims that wkup_uart is being enabled, but it is
> not.
> 
> 

Okay, I will change the $subject to reflect the patch better in v2.

Best,
Kendall