[PATCH] pmdomain: ti_sci: handle wakeup constraint for out-of-band wakeup

[Kendall Willis]

For devices capable of out-of-band system wakeups via I/O daisy chaining,
prevent sending wakeup constraints to the PM co-processor. This allows
the system to enter deeper low power modes, as the device is not marked
as requiring power.

Replaces the logic from commit b06bc4727991 ("pmdomain: ti_sci: handle
wake IRQs for IO daisy chain wakeups") since checking out-of-band wakeup
will cover the same functionality.

Detect out-of-band wakeup in the suspend path, and if it exists, skip
sending the constraint.

Signed-off-by: Kendall Willis <k-willis@xxxxxx>
---
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"
   (this patch): 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":
   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/pmdomain/ti/ti_sci_pm_domains.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pmdomain/ti/ti_sci_pm_domains.c b/drivers/pmdomain/ti/ti_sci_pm_domains.c
index e5d1934f78d9ee0a02eb05aa1301cd5a59e134d6..18d33bc35dee1b3bf6107af1e414db377d515199 100644
--- a/drivers/pmdomain/ti/ti_sci_pm_domains.c
+++ b/drivers/pmdomain/ti/ti_sci_pm_domains.c
@@ -91,8 +91,9 @@ static inline void ti_sci_pd_set_wkup_constraint(struct device *dev)
 		 * If device can wakeup using IO daisy chain wakeups,
 		 * we do not want to set a constraint.
 		 */
-		if (dev->power.wakeirq) {
-			dev_dbg(dev, "%s: has wake IRQ, not setting constraints\n", __func__);
+		if (device_out_band_wakeup(dev)) {
+			dev_dbg(dev, "%s: has out of band wakeup, not setting constraints\n", \
+					__func__);
 			return;
 		}
 

---
base-commit: f8f9c1f4d0c7a64600e2ca312dec824a0bc2f1da
change-id: 20251230-pmdomain-e71bed9b40f8

Best regards,
-- 
Kendall Willis <k-willis@xxxxxx>