leds: turris-omnia: Document driver private structures

Add documentation for driver private structures, `struct omnia_leds` and
`struct omnia_led`.

Signed-off-by: Marek Behún <kabel@kernel.org>
Link: https://lore.kernel.org/r/20241111100355.6978-7-kabel@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>

drivers/leds/leds-turris-omnia.c

@@ -18,6 +18,15 @@
 /* MCU controller I2C address 0x2a, needed for detecting MCU features */
 #define OMNIA_MCU_I2C_ADDR	0x2a
 
+/**
+ * struct omnia_led - per-LED part of driver private data structure
+ * @mc_cdev:		multi-color LED class device
+ * @subled_info:	per-channel information
+ * @cached_channels:	cached values of per-channel brightness that was sent to the MCU
+ * @on:			whether the LED was set on
+ * @hwtrig:		whether the LED blinking was offloaded to the MCU
+ * @reg:		LED identifier to the MCU
+ */
 struct omnia_led {
 	struct led_classdev_mc mc_cdev;
 	struct mc_subled subled_info[OMNIA_LED_NUM_CHANNELS];
@@ -28,6 +37,13 @@ struct omnia_led {
 
 #define to_omnia_led(l)		container_of(l, struct omnia_led, mc_cdev)
 
+/**
+ * struct omnia_leds - driver private data structure
+ * @client:			I2C client device
+ * @lock:			mutex to protect cached state
+ * @has_gamma_correction:	whether the MCU firmware supports gamma correction
+ * @leds:			flexible array of per-LED data
+ */
 struct omnia_leds {
 	struct i2c_client *client;
 	struct mutex lock;