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Diffstat (limited to 'Documentation/gpio/board.txt')
| -rw-r--r-- | Documentation/gpio/board.txt | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/gpio/board.txt b/Documentation/gpio/board.txt index 9edd5af31b3a..5fa069a80171 100644 --- a/Documentation/gpio/board.txt +++ b/Documentation/gpio/board.txt @@ -48,6 +48,15 @@ This property will make GPIOs 15, 16 and 17 available to the driver under the 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). +The second parameter of the gpiod_get() functions, the con_id string, has to be +the <function>-prefix of the GPIO suffixes ("gpios" or "gpio", automatically +looked up by the gpiod functions internally) used in the device tree. With above +"led-gpios" example, use the prefix without the "-" as con_id parameter: "led". + +Internally, the GPIO subsystem prefixes the GPIO suffix ("gpios" or "gpio") +with the string passed in con_id to get the resulting string +(snprintf(... "%s-%s", con_id, gpio_suffixes[]). + ACPI ---- ACPI also supports function names for GPIOs in a similar fashion to DT. |