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-rw-r--r--Documentation/gpio/board.txt25
1 files changed, 13 insertions, 12 deletions
diff --git a/Documentation/gpio/board.txt b/Documentation/gpio/board.txt
index b80606de545a..9edd5af31b3a 100644
--- a/Documentation/gpio/board.txt
+++ b/Documentation/gpio/board.txt
@@ -39,11 +39,11 @@ This property will make GPIOs 15, 16 and 17 available to the driver under the
struct gpio_desc *red, *green, *blue, *power;
- red = gpiod_get_index(dev, "led", 0);
- green = gpiod_get_index(dev, "led", 1);
- blue = gpiod_get_index(dev, "led", 2);
+ red = gpiod_get_index(dev, "led", 0, GPIOD_OUT_HIGH);
+ green = gpiod_get_index(dev, "led", 1, GPIOD_OUT_HIGH);
+ blue = gpiod_get_index(dev, "led", 2, GPIOD_OUT_HIGH);
- power = gpiod_get(dev, "power");
+ power = gpiod_get(dev, "power", GPIOD_OUT_HIGH);
The led GPIOs will be active-high, while the power GPIO will be active-low (i.e.
gpiod_is_active_low(power) will be true).
@@ -142,13 +142,14 @@ The driver controlling "foo.0" will then be able to obtain its GPIOs as follows:
struct gpio_desc *red, *green, *blue, *power;
- red = gpiod_get_index(dev, "led", 0);
- green = gpiod_get_index(dev, "led", 1);
- blue = gpiod_get_index(dev, "led", 2);
+ red = gpiod_get_index(dev, "led", 0, GPIOD_OUT_HIGH);
+ green = gpiod_get_index(dev, "led", 1, GPIOD_OUT_HIGH);
+ blue = gpiod_get_index(dev, "led", 2, GPIOD_OUT_HIGH);
- power = gpiod_get(dev, "power");
- gpiod_direction_output(power, 1);
+ power = gpiod_get(dev, "power", GPIOD_OUT_HIGH);
-Since the "power" GPIO is mapped as active-low, its actual signal will be 0
-after this code. Contrary to the legacy integer GPIO interface, the active-low
-property is handled during mapping and is thus transparent to GPIO consumers.
+Since the "led" GPIOs are mapped as active-high, this example will switch their
+signals to 1, i.e. enabling the LEDs. And for the "power" GPIO, which is mapped
+as active-low, its actual signal will be 0 after this code. Contrary to the legacy
+integer GPIO interface, the active-low property is handled during mapping and is
+thus transparent to GPIO consumers.