diff mbox series

[2/5] leds: leds-core: Implement the retain-state-shutdown property

Message ID 20210429205002.70245-3-eajames@linux.ibm.com
State Superseded
Headers show
Series leds: Support retaining state for the PCA955x | expand

Commit Message

Eddie James April 29, 2021, 8:49 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 2e495ff67856..f2f29318d312 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -354,10 +354,15 @@  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;
 	}
@@ -448,7 +453,8 @@  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);