[PATCH] serial: 8250: omap: set out-of-band wakeup if wakeup pinctrl exists

[PATCH] serial: 8250: omap: set out-of-band wakeup if wakeup pinctrl exists

[Kendall Willis]

In TI K3 SoCs, I/O daisy chaining is used to allow wakeup from UART when
the UART controller is off. Set UART device as wakeup capable using
out-of-band wakeup if the 'wakeup' pinctrl state exists and the device may
wakeup.

Signed-off-by: Kendall Willis <k-willis@ti.com>
---
Implementation
--------------
This patch is intended to be implemented along with the following
series. This patch has no dependencies on any of the other series:

1. "pmdomain: ti_sci: handle wakeup constraint for out-of-band wakeup":
   Skips setting constraints for wakeup sources that have out-of-band
   wakeup capability.
   https://github.com/kwillis01/linux/commits/v6.19/uart-daisy-chain/pmdomain

2. "serial: 8250: omap: set out-of-band wakeup if wakeup pinctrl exists"
   (this patch): Implements out-of-band wakeup from the UARTs for TI K3
   SoCs
   https://github.com/kwillis01/linux/tree/v6.19/uart-daisy-chain/uart-wakeup

3. "arm64: dts: ti: k3-am62: Support Main UART wakeup": Implements the
   functionality to wakeup the system from the Main UART
   https://github.com/kwillis01/linux/tree/b4/uart-daisy-chain-dts

Testing
-------
Tested on a AM62P SK EVM board with all series and dependencies
implemented. Suspend/resume verified with the Main UART wakeup source
by entering a keypress on the console.

This github branch has all the necessary patches to test the series
using v6.19-rc1:
https://github.com/kwillis01/linux/tree/v6.19/uart-daisy-chain/all
---
 drivers/tty/serial/8250/8250_omap.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 9e49ef48b851bf6cd3b04a77a4d0d7b4e064dc5f..6a5722b722650c1710e79fb76fc1a01cdeccc68f 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -1363,6 +1363,8 @@ static int omap8250_select_wakeup_pinctrl(struct device *dev,
 	if (!device_may_wakeup(dev))
 		return 0;
 
+	device_set_out_band_wakeup(dev);
+
 	return pinctrl_select_state(priv->pinctrl, priv->pinctrl_wakeup);
 }
 

---
base-commit: f8f9c1f4d0c7a64600e2ca312dec824a0bc2f1da
change-id: 20251230-uart-wakeup-00faeac7c994

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

Re: [PATCH] serial: 8250: omap: set out-of-band wakeup if wakeup pinctrl exists

[Dhruva Gole]

On Dec 30, 2025 at 15:24:51 -0600, Kendall Willis wrote:
> In TI K3 SoCs, I/O daisy chaining is used to allow wakeup from UART when
> the UART controller is off. Set UART device as wakeup capable using
> out-of-band wakeup if the 'wakeup' pinctrl state exists and the device may
> wakeup.
> 
> Signed-off-by: Kendall Willis <k-willis@ti.com>
> ---
> Implementation
> --------------
> This patch is intended to be implemented along with the following
> series. This patch has no dependencies on any of the other series:
> 
> 1. "pmdomain: ti_sci: handle wakeup constraint for out-of-band wakeup":
>    Skips setting constraints for wakeup sources that have out-of-band
>    wakeup capability.
>    https://github.com/kwillis01/linux/commits/v6.19/uart-daisy-chain/pmdomain
> 
> 2. "serial: 8250: omap: set out-of-band wakeup if wakeup pinctrl exists"
>    (this patch): Implements out-of-band wakeup from the UARTs for TI K3
>    SoCs
>    https://github.com/kwillis01/linux/tree/v6.19/uart-daisy-chain/uart-wakeup
> 
> 3. "arm64: dts: ti: k3-am62: Support Main UART wakeup": Implements the
>    functionality to wakeup the system from the Main UART
>    https://github.com/kwillis01/linux/tree/b4/uart-daisy-chain-dts
> 
> Testing
> -------
> Tested on a AM62P SK EVM board with all series and dependencies
> implemented. Suspend/resume verified with the Main UART wakeup source
> by entering a keypress on the console.
> 
> This github branch has all the necessary patches to test the series
> using v6.19-rc1:
> https://github.com/kwillis01/linux/tree/v6.19/uart-daisy-chain/all
> ---
>  drivers/tty/serial/8250/8250_omap.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
> index 9e49ef48b851bf6cd3b04a77a4d0d7b4e064dc5f..6a5722b722650c1710e79fb76fc1a01cdeccc68f 100644
> --- a/drivers/tty/serial/8250/8250_omap.c
> +++ b/drivers/tty/serial/8250/8250_omap.c
> @@ -1363,6 +1363,8 @@ static int omap8250_select_wakeup_pinctrl(struct device *dev,
>  	if (!device_may_wakeup(dev))
>  		return 0;
>  
> +	device_set_out_band_wakeup(dev);
> +

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

-- 
Best regards,
Dhruva Gole
Texas Instruments Incorporated

Re: [PATCH] serial: 8250: omap: set out-of-band wakeup if wakeup pinctrl exists

[Greg Kroah-Hartman]

On Tue, Dec 30, 2025 at 03:24:51PM -0600, Kendall Willis wrote:
> In TI K3 SoCs, I/O daisy chaining is used to allow wakeup from UART when
> the UART controller is off. Set UART device as wakeup capable using
> out-of-band wakeup if the 'wakeup' pinctrl state exists and the device may
> wakeup.
> 
> Signed-off-by: Kendall Willis <k-willis@ti.com>
> ---
> Implementation
> --------------
> This patch is intended to be implemented along with the following
> series. This patch has no dependencies on any of the other series:
> 
> 1. "pmdomain: ti_sci: handle wakeup constraint for out-of-band wakeup":
>    Skips setting constraints for wakeup sources that have out-of-band
>    wakeup capability.
>    https://github.com/kwillis01/linux/commits/v6.19/uart-daisy-chain/pmdomain
> 
> 2. "serial: 8250: omap: set out-of-band wakeup if wakeup pinctrl exists"
>    (this patch): Implements out-of-band wakeup from the UARTs for TI K3
>    SoCs
>    https://github.com/kwillis01/linux/tree/v6.19/uart-daisy-chain/uart-wakeup
> 
> 3. "arm64: dts: ti: k3-am62: Support Main UART wakeup": Implements the
>    functionality to wakeup the system from the Main UART
>    https://github.com/kwillis01/linux/tree/b4/uart-daisy-chain-dts

How am I to pull any of this into the mainline kernel tree?  If this is
dependant on those out-of-tree stuff, there's no need for me to take
this now, please submit this all together properly.

thanks,

greg k-h

Re: [PATCH] serial: 8250: omap: set out-of-band wakeup if wakeup pinctrl exists

[Kendall Willis]

On 1/16/26 07:16, Greg Kroah-Hartman wrote:
> On Tue, Dec 30, 2025 at 03:24:51PM -0600, Kendall Willis wrote:
>> In TI K3 SoCs, I/O daisy chaining is used to allow wakeup from UART when
>> the UART controller is off. Set UART device as wakeup capable using
>> out-of-band wakeup if the 'wakeup' pinctrl state exists and the device may
>> wakeup.
>>
>> Signed-off-by: Kendall Willis <k-willis@ti.com>
>> ---
>> Implementation
>> --------------
>> This patch is intended to be implemented along with the following
>> series. This patch has no dependencies on any of the other series:
>>
>> 1. "pmdomain: ti_sci: handle wakeup constraint for out-of-band wakeup":
>>     Skips setting constraints for wakeup sources that have out-of-band
>>     wakeup capability.
>>     https://github.com/kwillis01/linux/commits/v6.19/uart-daisy-chain/pmdomain
>>
>> 2. "serial: 8250: omap: set out-of-band wakeup if wakeup pinctrl exists"
>>     (this patch): Implements out-of-band wakeup from the UARTs for TI K3
>>     SoCs
>>     https://github.com/kwillis01/linux/tree/v6.19/uart-daisy-chain/uart-wakeup
>>
>> 3. "arm64: dts: ti: k3-am62: Support Main UART wakeup": Implements the
>>     functionality to wakeup the system from the Main UART
>>     https://github.com/kwillis01/linux/tree/b4/uart-daisy-chain-dts
> 
> How am I to pull any of this into the mainline kernel tree?  If this is
> dependant on those out-of-tree stuff, there's no need for me to take
> this now, please submit this all together properly.

This patch has no dependencies on the listed series. I listed them so 
that there was a full picture of the feature implementation. The 
"pmdomain: ti_sci: handle wakeup constraint for out-of-band wakeup" 
patch has been merged already [1]. The "arm64: dts: ti: k3-am62: Support 
Main UART wakeup" series is posted [2] and has a dependency on this 
patch. Sorry for the confusion with the GitHub links, in the future I 
either won't add them or will add lore links instead.

[1] https://lore.kernel.org/all/20251230-pmdomain-v1-1-3a009d1ff72e@ti.com/
[2] 
https://lore.kernel.org/all/20260106-b4-uart-daisy-chain-dts-v3-0-398a66258f2c@ti.com/

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

> 
> thanks,
> 
> greg k-h

Re: [PATCH] serial: 8250: omap: set out-of-band wakeup if wakeup pinctrl exists

[Greg Kroah-Hartman]

On Fri, Jan 16, 2026 at 09:37:44AM -0600, Kendall Willis wrote:
> On 1/16/26 07:16, Greg Kroah-Hartman wrote:
> > On Tue, Dec 30, 2025 at 03:24:51PM -0600, Kendall Willis wrote:
> > > In TI K3 SoCs, I/O daisy chaining is used to allow wakeup from UART when
> > > the UART controller is off. Set UART device as wakeup capable using
> > > out-of-band wakeup if the 'wakeup' pinctrl state exists and the device may
> > > wakeup.
> > > 
> > > Signed-off-by: Kendall Willis <k-willis@ti.com>
> > > ---
> > > Implementation
> > > --------------
> > > This patch is intended to be implemented along with the following
> > > series. This patch has no dependencies on any of the other series:
> > > 
> > > 1. "pmdomain: ti_sci: handle wakeup constraint for out-of-band wakeup":
> > >     Skips setting constraints for wakeup sources that have out-of-band
> > >     wakeup capability.
> > >     https://github.com/kwillis01/linux/commits/v6.19/uart-daisy-chain/pmdomain
> > > 
> > > 2. "serial: 8250: omap: set out-of-band wakeup if wakeup pinctrl exists"
> > >     (this patch): Implements out-of-band wakeup from the UARTs for TI K3
> > >     SoCs
> > >     https://github.com/kwillis01/linux/tree/v6.19/uart-daisy-chain/uart-wakeup
> > > 
> > > 3. "arm64: dts: ti: k3-am62: Support Main UART wakeup": Implements the
> > >     functionality to wakeup the system from the Main UART
> > >     https://github.com/kwillis01/linux/tree/b4/uart-daisy-chain-dts
> > 
> > How am I to pull any of this into the mainline kernel tree?  If this is
> > dependant on those out-of-tree stuff, there's no need for me to take
> > this now, please submit this all together properly.
> 
> This patch has no dependencies on the listed series. I listed them so that
> there was a full picture of the feature implementation. The "pmdomain:
> ti_sci: handle wakeup constraint for out-of-band wakeup" patch has been
> merged already [1]. The "arm64: dts: ti: k3-am62: Support Main UART wakeup"
> series is posted [2] and has a dependency on this patch. Sorry for the
> confusion with the GitHub links, in the future I either won't add them or
> will add lore links instead.
> 
> [1] https://lore.kernel.org/all/20251230-pmdomain-v1-1-3a009d1ff72e@ti.com/
> [2] https://lore.kernel.org/all/20260106-b4-uart-daisy-chain-dts-v3-0-398a66258f2c@ti.com/
> 
> Best,
> Kendall Willis <k-willis@ti.com>

Great, can you resend this then without that information to confuse me?
:)

thanks,

greg k-h