Documentation:leds: Add leds-st1202.rst

Add usage for sysfs hw_pattern entry for leds-st1202

Signed-off-by: Vicentiu Galanopulo <vicentiu.galanopulo@remote-tech.co.uk>
Link: https://lore.kernel.org/r/20241218183401.41687-2-vicentiu.galanopulo@remote-tech.co.uk
Signed-off-by: Lee Jones <lee@kernel.org>

Author: vicgal-remtech

Documentation/leds/index.rst

@@ -28,4 +28,5 @@ LEDs
    leds-mlxcpld
    leds-mt6370-rgb
    leds-sc27xx
+   leds-st1202.rst
    leds-qcom-lpg

Documentation/leds/leds-st1202.rst

@@ -0,0 +1,34 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============================================
+Kernel driver for STMicroelectronics LED1202
+============================================
+
+/sys/class/leds/<led>/hw_pattern
+--------------------------------
+
+Specify a hardware pattern for the ST1202 LED. The LED controller
+implements 12 low-side current generators with independent dimming
+control. Internal volatile memory allows the user to store up to 8
+different patterns. Each pattern is a particular output configuration
+in terms of PWM duty-cycle and duration (ms).
+
+To be compatible with the hardware pattern format, maximum 8 tuples of
+brightness (PWM) and duration must be written to hw_pattern.
+
+- Min pattern duration: 22 ms
+- Max pattern duration: 5660 ms
+
+The format of the hardware pattern values should be:
+"brightness duration brightness duration ..."
+
+/sys/class/leds/<led>/repeat
+----------------------------
+
+Specify a pattern repeat number, which is common for all channels.
+Default is 1; negative numbers and 0 are invalid.
+
+This file will always return the originally written repeat number.
+
+When the 255 value is written to it, all patterns will repeat
+indefinitely.