@@ -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.
With commit 39b2bbe3d715 ("gpio: add flags argument to gpiod_get*() functions") the gpiod_get*() functions got a 'flags' parameter. Reflect this in the documentation, too. Signed-off-by: Dirk Behme <dirk.behme@gmail.com> --- Changes in v3: Add a short note to mention the fact that the example will switch the LEDs on, similarly to the existing explanation for the "power" GPIO. Documentation/gpio/board.txt | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-)