* [PATCH] Documentation: gpio: consumer: describe the con_id parameter
@ 2015-07-11 5:46 Dirk Behme
2015-07-14 5:01 ` Alexandre Courbot
0 siblings, 1 reply; 2+ messages in thread
From: Dirk Behme @ 2015-07-11 5:46 UTC (permalink / raw)
To: linux-gpio; +Cc: Dirk Behme
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 <dirk.behme@gmail.com>
---
Documentation/gpio/consumer.txt | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt
index 75542b9..d0d1e47 100644
--- a/Documentation/gpio/consumer.txt
+++ b/Documentation/gpio/consumer.txt
@@ -39,6 +39,18 @@ 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"):
+
+* 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 gpiod 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:
--
2.4.5
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] Documentation: gpio: consumer: describe the con_id parameter
2015-07-11 5:46 [PATCH] Documentation: gpio: consumer: describe the con_id parameter Dirk Behme
@ 2015-07-14 5:01 ` Alexandre Courbot
0 siblings, 0 replies; 2+ messages in thread
From: Alexandre Courbot @ 2015-07-14 5:01 UTC (permalink / raw)
To: Dirk Behme; +Cc: linux-gpio@vger.kernel.org
On Sat, Jul 11, 2015 at 2:46 PM, Dirk Behme <dirk.behme@gmail.com> wrote:
> 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.
Good idea!
>
> Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
> ---
> Documentation/gpio/consumer.txt | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt
> index 75542b9..d0d1e47 100644
> --- a/Documentation/gpio/consumer.txt
> +++ b/Documentation/gpio/consumer.txt
> @@ -39,6 +39,18 @@ 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"):
It may be useful to explain that "gpios" and "gpio" are both looked up
by gpiod functions, otherwise the reader might wonder how to choose
one or the other.
> +
> +* If the GPIO description is just named with one of the GPIO suffixes
> + ("gpios" or "gpio") use NULL.
add a comma here:
("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 gpiod subsystem prefixes the GPIO suffix
s/gpiod/GPIO. gpiod is not a subsystem, just a set of functions.
Otherwise it looks good. Feel free to add my
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
to the next revision.
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