[PATCH v2 3/4] gpio: raspberrypi-exp: Driver for RPi3 GPIO expander via mailbox service

Baruch Siach baruch at tkos.co.il
Sat Jan 13 22:08:40 PST 2018


Hi Stefan,

Thanks for reviewing. Please find below a few questions.

On Sat, Jan 13, 2018 at 11:33:15AM +0100, Stefan Wahren wrote: 
> > +	default RASPBERRYPI_FIRMWARE
> > +	depends on OF_GPIO && RASPBERRYPI_FIRMWARE && \
> > +		(ARCH_BCM2835 || COMPILE_TEST)
> 
> Since this is default on RASPBERRYPI_FIRMWARE, we could remove it from the dependencies.

This driver does not work when RASPBERRYPI_FIRMWARE is not enabled. So the 
driver should not be selectable, regardless of its default enable/disable 
state.

> > +	help
> > +	  Turn on GPIO support for the expander on Raspberry Pi 3 boards, using
> > +	  the firmware mailbox to communicate with VideoCore on BCM283x chips.
> > +

[...]

> > --- /dev/null
> > +++ b/drivers/gpio/gpio-raspberrypi-exp.c
> > @@ -0,0 +1,258 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + *  Raspberry Pi 3 expander GPIO driver
> > + *
> > + *  Uses the firmware mailbox service to communicate with the
> > + *  GPIO expander on the VPU.
> > + *
> > + *  Copyright (C) 2017 Raspberry Pi Trading Ltd.
> 
> 2018?

Why? Raspberry Pi Trading Ltd added no code to this driver in 2018.

[...]

> > +static struct platform_driver rpi_exp_gpio_driver = {
> > +	.driver	= {
> > +		.name		= MODULE_NAME,
> > +		.owner		= THIS_MODULE,
> 
> Please drop this, too.

Why? Recent GPIO drivers include this line. I have seen no commits removing 
.owner from GPIO drivers in mainline or in current development tree.

baruch

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