Re: [PATCH 3/3] input: gpio_keys: Make use of the device property API

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Tue, Mar 1, 2016 at 2:52 PM, Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> On Mon, Feb 29, 2016 at 04:24:16PM +0000, sergk sergk2mail wrote:

>> But how then to obtain gpio name or if it is possible the list of all
>> available names?
>> For example decoded ACPI DSDT shows the following:
>> how to get gpio name for mentioned in your reply function?
>
> For existing systems that do not provide _DSD naming for GPIOs you still
> can provide them in the driver itself (ugly but works). See
> Documentation/acpi/gpio-properties.txt chapter "ACPI GPIO Mappings
> Provided by Drivers".

I just this merge window added an ABI for userspace to read name
of the GPIO line and also consumer name ("label") by using the
two strings stored in struct gpio_desc.

Currently this will be initialized per-offset from the seldom used
char names[] in struct gpio_chip, if not NULL.

We're working on DT bindings to set this per-line from the DT, and
if ACPI has a mechanism to name individual lines, please submit
patches for assigning this properly! (Hi Mika ;)

For consumers struct gpio_desc is opaque, but if they actually need
to know the name of a line we can add gpiod_get_name(struct gpio_desc *)
but then I want to know a usecase. debugfs and userspace ABI is
already displaying it just fine.

Yours,
Linus Walleij
--
To unsubscribe from this list: send the line "unsubscribe linux-gpio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html