Re: [RFC PATCH v3 4/5] input: add onkey driver for Marvell 88PM886 PMIC

["Karel Balej" <karelb@gimli.ms.mff.cuni.cz>]

Dmitry Torokhov, 2024-03-04T17:10:59-08:00:
> On Mon, Mar 04, 2024 at 09:28:45PM +0100, Karel Balej wrote:
> > Dmitry,
> > 
> > Dmitry Torokhov, 2024-03-03T12:39:46-08:00:
> > > On Sun, Mar 03, 2024 at 11:04:25AM +0100, Karel Balej wrote:
> > > > From: Karel Balej <balejk@matfyz.cz>
> > > > 
> > > > Marvell 88PM886 PMIC provides onkey among other things. Add client
> > > > driver to handle it. The driver currently only provides a basic support
> > > > omitting additional functions found in the vendor version, such as long
> > > > onkey and GPIO integration.
> > > > 
> > > > Signed-off-by: Karel Balej <balejk@matfyz.cz>
> > > > ---
> > > > 
> > > > Notes:
> > > >     RFC v3:
> > > >     - Drop wakeup-source.
> > > >     RFC v2:
> > > >     - Address Dmitry's feedback:
> > > >       - Sort includes alphabetically.
> > > >       - Drop onkey->irq.
> > > >       - ret -> err in irq_handler and no initialization.
> > > >       - Break long lines and other formatting.
> > > >       - Do not clobber platform_get_irq error.
> > > >       - Do not set device parent manually.
> > > >       - Use input_set_capability.
> > > >       - Use the wakeup-source DT property.
> > > >       - Drop of_match_table.
> > >
> > > I only said that you should not be using of_match_ptr(), but you still
> > > need to have of_match_table set and have MODULE_DEVICE_TABLE() for the
> > > proper module loading support.
> > 
> > I removed of_match_table because I no longer need compatible for this --
> > there are no device tree properties and the driver is being instantiated
> > by the MFD driver.
> > 
> > Is the MODULE_DEVICE_TABLE() entry needed for the driver to probe when
> > compiled as module? If that is the case, given what I write above, am I
> > correct that MODULE_DEVICE_TABLE(platform,...) would be the right thing
> > to use here?
>
> Yes, if uevent generated for the device is "platform:<name>" then
> MODULE_DEVICE_TABLE(platform,...) will suffice. I am not sure how MFD
> sets it up (OF modalias or platform), but you should be able to check
> the format looking at the "uevent" attribute for your device in sysfs
> (/sys/devices/bus/platform/...). 

The uevent is indeed platform.

But since there is only one device, perhaps having a device table is
superfluous and using `MODULE_ALIAS("platform:88pm886-onkey")` is more
fitting?

Although I don't understand why this is even necessary when the driver
name is such and the module is registered using
`module_platform_driver`...

Thank you, best regards,
K. B.