[PATCH v2 2/4] gpio - Add EXAR XRA1403 SPI GPIO expander driver

["Han, Nandor (GE Healthcare)" <nandor.han@ge.com>]

> -----Original Message-----
> From: Linus Walleij [mailto:linus.walleij@linaro.org]
> Sent: 24 April 2017 16:47
> To: Han, Nandor (GE Healthcare) <nandor.han@ge.com>
> Cc: Greg KH <gregkh@linuxfoundation.org>; David S. Miller <davem@davemloft.net>; Geert Uytterhoeven <geert@linux-
> m68k.org>; Mauro Carvalho Chehab <mchehab@kernel.org>; Daniel Vetter <daniel.vetter@ffwll.ch>; Alexandre Courbot
> <gnurou@gmail.com>; Rob Herring <robh+dt@kernel.org>; Mark Rutland <mark.rutland@arm.com>; linux-
> gpio@vger.kernel.org; devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; Malinen, Semi (GE Healthcare)
> <semi.malinen@ge.com>
> Subject: EXT: Re: [PATCH v2 2/4] gpio - Add EXAR XRA1403 SPI GPIO expander driver
> 
> On Thu, Apr 13, 2017 at 12:27 PM, Nandor Han <nandor.han@ge.com> wrote:
> 
> > This is a simple driver that provides a /sys/class/gpio
> > interface for controlling and configuring the GPIO lines.
> > It does not provide support for chip select or interrupts.
> >
> > Signed-off-by: Nandor Han <nandor.han@ge.com>
> > Signed-off-by: Semi Malinen <semi.malinen@ge.com>
> 
> I almost want to make the driver depend on !GPIO_SYSFS because
> of this commit message.
> 
> DO NOT USE OR ENCOURAGE THE USE OF THE GPIO SYSFS
> INTERFACE.
> 

Ahh.. I forgot to change this commit message. Sorry I will change it ASAP.

> Use the character device.
> 
> Use the example in tools/gpio/* as a guideline and testbed.
> 
> Use libgpiod as a rich userspace.
> 
> And the commit message should state that this is a driver
> for such and such Exar hardware instead.
> 
> Thanks.
> 
> > +#include <linux/bitops.h>
> > +#include <linux/gpio/driver.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/mutex.h>
> > +#include <linux/of_device.h>
> > +#include <linux/of_gpio.h>
> > +#include <linux/spi/spi.h>
> > +#include <linux/regmap.h>
> 
> You are missing
> #include <linux/seq_file.h>
> 
> and that is why the build robot is complaining.
> 

I've noticed that. I will change it in the next rev.

> Yours,
> Linus Walleij

Thanks,
   Nandy