gpio_led: add support for inverted polarity

[platform/kernel/u-boot.git] / README

diff --git a/README b/README
index 7b393b7..5def773 100644 (file)
--- a/README
+++ b/README
@@ -1971,6 +1971,13 @@ CBFS (Coreboot Filesystem) support
                status LED backend implementation. Define CONFIG_GPIO_LED
                to include the gpio_led driver in the U-Boot binary.
 
+               CONFIG_GPIO_LED_INVERTED_TABLE
+               Some GPIO connected LEDs may have inverted polarity in which
+               case the GPIO high value corresponds to LED off state and
+               GPIO low value corresponds to LED on state.
+               In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
+               with a list of GPIO LEDs that have inverted polarity.
+
 - CAN Support: CONFIG_CAN_DRIVER
 
                Defining CONFIG_CAN_DRIVER enables CAN driver support