The con_id parameter has to match the GPIO description and is automatically extended by the GPIO suffix if not NULL. I had to look into the code to understand this and properly find the GPIO I've been looking for, so document this.
Signed-off-by: Dirk Behme <[email protected]> Acked-by: Alexandre Courbot <[email protected]> --- Changes in v2: Incorporate the review comments from Alexandre. Documentation/gpio/consumer.txt | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index 75542b9..5f7437b 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -39,6 +39,19 @@ device that displays digits), an additional index argument can be specified: const char *con_id, unsigned int idx, enum gpiod_flags flags) +The con_id string parameter has to be either NULL or the prefix of the GPIO +suffixes ("gpios" or "gpio", automatically looked up by the gpiod functions +internally): + +* If the GPIO description is just named with one of the GPIO suffixes + ("gpios" or "gpio"), use NULL. +* If the GPIO description is prefixed with anything, e.g. "reset-gpios", use the + prefix without the "-" as con_id parameter (in this example "reset"). + +In case con_id is not NULL, 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[]). + The flags parameter is used to optionally specify a direction and initial value for the GPIO. Values can be: -- 2.4.6 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
