diff options
| -rw-r--r-- | Documentation/gpio/board.txt | 25 |
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 | |||
| 39 | 39 | ||
| 40 | struct gpio_desc *red, *green, *blue, *power; | 40 | struct gpio_desc *red, *green, *blue, *power; |
| 41 | 41 | ||
| 42 | red = gpiod_get_index(dev, "led", 0); | 42 | red = gpiod_get_index(dev, "led", 0, GPIOD_OUT_HIGH); |
| 43 | green = gpiod_get_index(dev, "led", 1); | 43 | green = gpiod_get_index(dev, "led", 1, GPIOD_OUT_HIGH); |
| 44 | blue = gpiod_get_index(dev, "led", 2); | 44 | blue = gpiod_get_index(dev, "led", 2, GPIOD_OUT_HIGH); |
| 45 | 45 | ||
| 46 | power = gpiod_get(dev, "power"); | 46 | power = gpiod_get(dev, "power", GPIOD_OUT_HIGH); |
| 47 | 47 | ||
| 48 | The led GPIOs will be active-high, while the power GPIO will be active-low (i.e. | 48 | The led GPIOs will be active-high, while the power GPIO will be active-low (i.e. |
| 49 | gpiod_is_active_low(power) will be true). | 49 | 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: | |||
| 142 | 142 | ||
| 143 | struct gpio_desc *red, *green, *blue, *power; | 143 | struct gpio_desc *red, *green, *blue, *power; |
| 144 | 144 | ||
| 145 | red = gpiod_get_index(dev, "led", 0); | 145 | red = gpiod_get_index(dev, "led", 0, GPIOD_OUT_HIGH); |
| 146 | green = gpiod_get_index(dev, "led", 1); | 146 | green = gpiod_get_index(dev, "led", 1, GPIOD_OUT_HIGH); |
| 147 | blue = gpiod_get_index(dev, "led", 2); | 147 | blue = gpiod_get_index(dev, "led", 2, GPIOD_OUT_HIGH); |
| 148 | 148 | ||
| 149 | power = gpiod_get(dev, "power"); | 149 | power = gpiod_get(dev, "power", GPIOD_OUT_HIGH); |
| 150 | gpiod_direction_output(power, 1); | ||
| 151 | 150 | ||
| 152 | Since the "power" GPIO is mapped as active-low, its actual signal will be 0 | 151 | Since the "led" GPIOs are mapped as active-high, this example will switch their |
| 153 | after this code. Contrary to the legacy integer GPIO interface, the active-low | 152 | signals to 1, i.e. enabling the LEDs. And for the "power" GPIO, which is mapped |
| 154 | property is handled during mapping and is thus transparent to GPIO consumers. | 153 | as active-low, its actual signal will be 0 after this code. Contrary to the legacy |
| 154 | integer GPIO interface, the active-low property is handled during mapping and is | ||
| 155 | thus transparent to GPIO consumers. | ||