HID: wacom: Remove AES power_supply after extended inactivity

Even if a user does not use their AES pen for an extended period,
the battery power supply attributes continue to exist.
This results in the desktop showing battery status for a pen
that is no longer in use and which may in fact be in a different
state (e.g. the user may be charging the pen).
To avoid confusion and ensure userspace has an accurate view
of the battery state, this patch automatically removes
the power_supply after 30 minutes of inactivity.

Signed-off-by: Tatsunosuke Tobita <tatsunosuke.tobita@wacom.com>
Reviewed-by: Jason Gerecke <Jason.Gerecke@wacom.com>
Reviewed-by: Aaron Skomra <aaron.skomra@wacom.com>
Reviewed-by: Josh Dickens <joshua.dickens@wacom.com>
Link: https://lore.kernel.org/r/20231114235729.6867-1-tatsunosuke.wacom@gmail.com
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index 3f704b8072e8..b613f11ed949 100644
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -1813,6 +1813,13 @@ static void wacom_destroy_battery(struct wacom *wacom)
 	}
 }
 
+static void wacom_aes_battery_handler(struct work_struct *work)
+{
+	struct wacom *wacom = container_of(work, struct wacom, aes_battery_work.work);
+
+	wacom_destroy_battery(wacom);
+}
+
 static ssize_t wacom_show_speed(struct device *dev,
 				struct device_attribute
 				*attr, char *buf)
@@ -2794,6 +2801,7 @@ static int wacom_probe(struct hid_device *hdev,
 
 	mutex_init(&wacom->lock);
 	INIT_DELAYED_WORK(&wacom->init_work, wacom_init_work);
+	INIT_DELAYED_WORK(&wacom->aes_battery_work, wacom_aes_battery_handler);
 	INIT_WORK(&wacom->wireless_work, wacom_wireless_work);
 	INIT_WORK(&wacom->battery_work, wacom_battery_work);
 	INIT_WORK(&wacom->remote_work, wacom_remote_work);