[PATCH v4 06/12] leds: trigger: netdev: Implement offloaded() callback

"netdev" can run in hardware control according to hardware capabilities
and trigger options.

Implement offloaded() callback to provide its hardware control state to
the LED core, and document the relation between the custom "offloaded"
attribute and the generic "trigger_may_offload" attribute.

Signed-off-by: Rong Zhang <[email protected]>
---
Changes in v3:
- Do not deprecate netdev's "offloaded" attribute (thanks Thomas
  Weißschuh)
- Document the relation between the custom "offloaded" attribute and the
  generic "trigger_may_offload" attribute (ditto)
---
 Documentation/ABI/testing/sysfs-class-led                | 3 +++
 Documentation/ABI/testing/sysfs-class-led-trigger-netdev | 3 +++
 drivers/leds/trigger/ledtrig-netdev.c                    | 8 ++++++++
 3 files changed, 14 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-class-led b/Documentation/ABI/testing/sysfs-class-led
index 5afb307c935a..2a13c77aee22 100644
--- a/Documentation/ABI/testing/sysfs-class-led
+++ b/Documentation/ABI/testing/sysfs-class-led
@@ -100,6 +100,9 @@ Description:
 		- `[foo_trigger]`: the trigger is selected and offloaded to
 		  hardware.
 
+		The "netdev" trigger also provides a custom attribute to
+		indicate its state, see `/sys/class/leds/<led>/offloaded`.
+
 What:		/sys/class/leds/<led>/inverted
 Date:		January 2011
 KernelVersion:	2.6.38
diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-netdev b/Documentation/ABI/testing/sysfs-class-led-trigger-netdev
index ed46b37ab8a2..a5146ea1e3e6 100644
--- a/Documentation/ABI/testing/sysfs-class-led-trigger-netdev
+++ b/Documentation/ABI/testing/sysfs-class-led-trigger-netdev
@@ -75,6 +75,9 @@ Description:
 		If 1, the LED blinking in requested mode is offloaded to
 		hardware.
 
+		LED trigger core also provides a generic attribute for this
+		purpose, see `/sys/class/leds/<led>/trigger_may_offload`.
+
 What:		/sys/class/leds/<led>/link_10
 Date:		Jun 2023
 KernelVersion:	6.5
diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c
index 64c078e997f2..a26109ca4b1c 100644
--- a/drivers/leds/trigger/ledtrig-netdev.c
+++ b/drivers/leds/trigger/ledtrig-netdev.c
@@ -754,10 +754,18 @@ static void netdev_trig_deactivate(struct led_classdev *led_cdev)
 	kfree(trigger_data);
 }
 
+static bool netdev_trig_offloaded(struct led_classdev *led_cdev)
+{
+	struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
+
+	return trigger_data->hw_control;
+}
+
 static struct led_trigger netdev_led_trigger = {
 	.name = "netdev",
 	.activate = netdev_trig_activate,
 	.deactivate = netdev_trig_deactivate,
+	.offloaded = netdev_trig_offloaded,
 	.groups = netdev_trig_groups,
 };
 

-- 
2.53.0