[thermal: thermal/next] thermal/core: Make the userspace governor deprecated

The following commit has been merged into the thermal/next branch of thermal:

Commit-ID:     0275c9fb0eff3f77d437ab8a95b16e6f8f80b7f2
Gitweb:        https://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux.git//0275c9fb0eff3f77d437ab8a95b16e6f8f80b7f2
Author:        Daniel Lezcano [off-list ref]
AuthorDate:    Tue, 19 Oct 2021 18:35:05 +02:00
Committer:     Daniel Lezcano [off-list ref]
CommitterDate: Thu, 21 Oct 2021 17:35:05 +02:00

thermal/core: Make the userspace governor deprecated

The userspace governor is sending temperature when polling is active
and trip point crossed events. Nothing else.

AFAICT, this governor is used with custom kernels making the userspace
governor co-existing with another governor on the same thermal zone
because there was no notification mechanism, implying a hack in the
framework to support this configuration.

The new netlink thermal notification is able to provide more
information than the userspace governor and give the opportunity to
the users of this governor to replace it by a dedicated notification
framework.

The userspace governor will be removed as its usage is no longer
needed.

Add a warning message to tell the userspace governor is deprecated.

Signed-off-by: Daniel Lezcano <redacted>
Acked-by: Rafael J. Wysocki <redacted>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20211019163506.2831454-1-daniel.lezcano@linaro.org (local)
---
 drivers/thermal/gov_user_space.c |  9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/thermal/gov_user_space.c b/drivers/thermal/gov_user_space.c
index 82a7198..f4fe050 100644
--- a/drivers/thermal/gov_user_space.c
+++ b/drivers/thermal/gov_user_space.c

@@ -15,6 +15,14 @@
 
 #include "thermal_core.h"
 
+static int user_space_bind(struct thermal_zone_device *tz)
+{
+	pr_warn("Userspace governor deprecated: use thermal netlink "	\
+		"notification instead\n");
+
+	return 0;
+}
+
 /**
  * notify_user_space - Notifies user space about thermal events
  * @tz: thermal_zone_device

@@ -43,5 +51,6 @@ static int notify_user_space(struct thermal_zone_device *tz, int trip)
 static struct thermal_governor thermal_gov_user_space = {
 	.name		= "user_space",
 	.throttle	= notify_user_space,
+	.bind_to_tz	= user_space_bind,
 };
 THERMAL_GOVERNOR_DECLARE(thermal_gov_user_space);