Re: [PATCH v3 13/15] input: gpio_keys_polled - Add ACPI probing support

Dmitry Torokhov
2014-10-01T16:28:09Z

On Wed, Oct 01, 2014 at 12:15:35PM +0300, Mika Westerberg wrote:
> On Wed, Oct 01, 2014 at 12:48:46AM -0700, Dmitry Torokhov wrote:
> > On Wed, Oct 01, 2014 at 04:20:43AM +0200, Rafael J. Wysocki wrote:
> > > From: Mika Westerberg <mika.westerberg@linux.intel.com>
> > >
> > > Allow the driver to probe from ACPI namespace.
> > >
> > > Signed-off-by: Aaron Lu <aaron.lu@intel.com>
> > > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > > ---
> > > drivers/input/keyboard/gpio_keys_polled.c | 7 +++++++
> > > 1 file changed, 7 insertions(+)
> > >
> > > Index: linux-pm/drivers/input/keyboard/gpio_keys_polled.c
> > > ===================================================================
> > > --- linux-pm.orig/drivers/input/keyboard/gpio_keys_polled.c
> > > +++ linux-pm/drivers/input/keyboard/gpio_keys_polled.c
> > > @@ -181,6 +181,12 @@ static const struct of_device_id gpio_ke
> > > };
> > > MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
> > >
> > > +static const struct acpi_device_id gpio_keys_polled_acpi_match[] = {
> > > + { "PRP0001" }, /* Device Tree shoehorned into ACPI */
> > > + { },
> > > +};
> > > +MODULE_DEVICE_TABLE(acpi, gpio_keys_polled_acpi_match);
> > > +
> > > static int gpio_keys_polled_probe(struct platform_device *pdev)
> > > {
> > > struct device *dev = &pdev->dev;
> > > @@ -309,6 +315,7 @@ static struct platform_driver gpio_keys_
> > > .name = DRV_NAME,
> > > .owner = THIS_MODULE,
> > > .of_match_table = gpio_keys_polled_of_match,
> > > + .acpi_match_table = gpio_keys_polled_acpi_match,
> > o
> > Hmm, why do we need the generic "PRP0001" in every driver? The ACPI device
> > should have PRP0001 and ACPI bus should know to look into OF matching table
> > for such devices.
>
> Arnd had a good idea for this. How about,
>
> .acpi_match_table = acpi_match_by_of_compatible,
>
> where acpi_match_by_of_compatible is provided by ACPI core? Does that
> work better for you?

I still do not see the point. ACPI core knows how to handle
drv->of_match_table, so unless we need to support ACPI_only binding in a
given driver I do not understand why we need to add boilerplate code.

Thanks.

--
Dmitry