linux-kernel - [PATCH v2 1/3] pmdomain: core: Introduce device_set/get_out_band

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Message-Id: <20250801-pm-v2-1-97c8fb2a433c@nxp.com>
Date: Fri, 01 Aug 2025 12:34:22 +0800
From: Peng Fan <peng.fan@....com>
To: Ulf Hansson <ulf.hansson@...aro.org>, 
 "Rafael J. Wysocki" <rafael@...nel.org>, Len Brown <lenb@...nel.org>, 
 Pavel Machek <pavel@...nel.org>, Peter Chen <peter.chen@...nel.org>, 
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
 Shawn Guo <shawnguo@...nel.org>, Sascha Hauer <s.hauer@...gutronix.de>, 
 Pengutronix Kernel Team <kernel@...gutronix.de>, 
 Fabio Estevam <festevam@...il.com>, 
 Thinh Nguyen <Thinh.Nguyen@...opsys.com>, 
 Vincent Guittot <vincent.guittot@...aro.org>, Xu Yang <xu.yang_2@....com>
Cc: linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org, 
 linux-usb@...r.kernel.org, imx@...ts.linux.dev, arm-scmi@...r.kernel.org, 
 linux-arm-kernel@...ts.infradead.org, Peng Fan <peng.fan@....com>
Subject: [PATCH v2 1/3] pmdomain: core: Introduce
 device_set/get_out_band_wakeup()

For some cases, a device could still wakeup the system even if its power
domain is in off state, because the device's wakeup hardware logic is
in an always-on domain.

To support this case, introduce device_set/get_out_band_wakeup() to
allow device drivers to control the behaviour in genpd for a device
that is attached to it.

Signed-off-by: Peng Fan <peng.fan@....com>
---
 drivers/pmdomain/core.c   |  6 ++++--
 include/linux/pm.h        |  1 +
 include/linux/pm_wakeup.h | 17 +++++++++++++++++
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index 0006ab3d078972cc72a6dd22a2144fb31443e3da..8e37758cea88a9ee051ad9fb13bdd3feb4f8745e 100644
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c
@@ -1549,7 +1549,8 @@ static int genpd_finish_suspend(struct device *dev,
 	if (ret)
 		return ret;

-	if (device_awake_path(dev) && genpd_is_active_wakeup(genpd))
+	if (device_awake_path(dev) && genpd_is_active_wakeup(genpd) &&
+	    !device_get_out_band_wakeup(dev))
 		return 0;

 	if (genpd->dev_ops.stop && genpd->dev_ops.start &&
@@ -1604,7 +1605,8 @@ static int genpd_finish_resume(struct device *dev,
 	if (IS_ERR(genpd))
 		return -EINVAL;

-	if (device_awake_path(dev) && genpd_is_active_wakeup(genpd))
+	if (device_awake_path(dev) && genpd_is_active_wakeup(genpd) &&
+	    !device_get_out_band_wakeup(dev))
 		return resume_noirq(dev);

 	genpd_lock(genpd);
diff --git a/include/linux/pm.h b/include/linux/pm.h
index cc7b2dc28574c24ece2f651352d4d23ecaf15f31..5b28a4f2e87e2aa34acc709e146ce729acace344 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -684,6 +684,7 @@ struct dev_pm_info {
 	bool			smart_suspend:1;	/* Owned by the PM core */
 	bool			must_resume:1;		/* Owned by the PM core */
 	bool			may_skip_resume:1;	/* Set by subsystems */
+	bool			out_band_wakeup:1;
 	bool			strict_midlayer:1;
 #else
 	bool			should_wakeup:1;
diff --git a/include/linux/pm_wakeup.h b/include/linux/pm_wakeup.h
index c838b4a30f876ef5a66972d16f461cfba9ff2814..c461c7edef6f7927d696b7d18b59a6a1147f53a3 100644
--- a/include/linux/pm_wakeup.h
+++ b/include/linux/pm_wakeup.h
@@ -94,6 +94,16 @@ static inline void device_set_wakeup_path(struct device *dev)
 	dev->power.wakeup_path = true;
 }

+static inline void device_set_out_band_wakeup(struct device *dev, bool capable)
+{
+	dev->power.out_band_wakeup = capable;
+}
+
+static inline bool device_get_out_band_wakeup(struct device *dev)
+{
+	return dev->power.out_band_wakeup;
+}
+
 /* drivers/base/power/wakeup.c */
 extern struct wakeup_source *wakeup_source_register(struct device *dev,
 						    const char *name);
@@ -162,6 +172,13 @@ static inline bool device_wakeup_path(struct device *dev)

 static inline void device_set_wakeup_path(struct device *dev) {}

+static inline void device_set_out_band_wakeup(struct device *dev, bool capable) {}
+
+static inline bool device_get_out_band_wakeup(struct device *dev)
+{
+	return false;
+}
+
 static inline void __pm_stay_awake(struct wakeup_source *ws) {}

 static inline void pm_stay_awake(struct device *dev) {}

-- 
2.37.1