diff mbox series

[v2,2/7] leds: leds-core: Implement the retain-state-shutdown property

Message ID 20210716220331.49303-3-eajames@linux.ibm.com
State Accepted
Commit 419066324e19a47b98cdcf5defda42de555a8957
Headers show
Series leds: Support retaining state for the PCA955x | expand

Commit Message

Eddie James July 16, 2021, 10:03 p.m. UTC 
Read the retain-state-shutdown device tree property to set the
existing LED_RETAIN_AT_SHUTDOWN flag. Then check the flag when
unregistering, and if set, don't set the brightness to OFF. This
is useful for systems that want to keep the HW state of the LED
across reboots.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/leds/led-class.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index f704391d57a8..f4bb02f6e042 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -350,10 +350,15 @@  int led_classdev_register_ext(struct device *parent,
 		if (ret < 0)
 			return ret;
 
-		if (init_data->fwnode)
+		if (init_data->fwnode) {
 			fwnode_property_read_string(init_data->fwnode,
 				"linux,default-trigger",
 				&led_cdev->default_trigger);
+
+			if (fwnode_property_present(init_data->fwnode,
+						    "retain-state-shutdown"))
+				led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
+		}
 	} else {
 		proposed_name = led_cdev->name;
 	}
@@ -444,7 +449,8 @@  void led_classdev_unregister(struct led_classdev *led_cdev)
 	/* Stop blinking */
 	led_stop_software_blink(led_cdev);
 
-	led_set_brightness(led_cdev, LED_OFF);
+	if (!(led_cdev->flags & LED_RETAIN_AT_SHUTDOWN))
+		led_set_brightness(led_cdev, LED_OFF);
 
 	flush_work(&led_cdev->set_brightness_work);