On Wed, 2013-06-26 at 10:55 +0300, Andy Shevchenko wrote:
> On Tue, 2013-06-25 at 18:53 -0700, Darren Hart wrote:
> > Request and export the user-configurable GPIO lines to sysfs. This provides
> > a
> > label readable in /debugfs/gpio and a simple interface for experimenting
> > with
> > GPIO on the MinnowBoard.
> >
> > This is separate from the minnowboard driver to provide users with the
> > flexibility to write kernel drivers for their own devices using these GPIO
> > lines.
>
> Few comments below.
>
> > --- a/drivers/platform/x86/Kconfig
> > +++ b/drivers/platform/x86/Kconfig
> > @@ -35,6 +35,24 @@ config MINNOWBOARD
> >
> > If you have a MinnowBoard, say Y or M here.
> >
> > +if MINNOWBOARD
> > +config MINNOWBOARD_GPIO
> > + tristate "MinnowBoard Expansion GPIO"
> > + depends on MINNOWBOARD
> > + default n
>
> Like you already had been told you don't need to have default n.
>
> > --- /dev/null
> > +++ b/drivers/platform/x86/minnowboard-gpio.c
>
> > +#include <linux/platform_device.h>
> > +#include <linux/module.h>
> > +#include <linux/gpio.h>
> > +#include <linux/gpio_keys.h>
> > +#include <linux/input.h>
> > +#include <linux/minnowboard.h>
>
> + empty line here?
>
> > +#include "minnowboard-gpio.h"
>
> > +static int __init minnow_gpio_module_init(void)
> > +{
> > + int err;
> > +
> > + err = -ENODEV;
> > + if (!minnow_detect())
> > + goto out;
> > +
> > +#ifdef MODULE
> > +#ifdef CONFIG_MINNOWBOARD_MODULE
>
> And less ifdefs with IS_MODULE().
>
All good to here and consistent with Olof's comments. Thanks, I will
include in V2.
> > + if (request_module("minnowboard"))
> > + goto out;
> > +#endif
> > +#endif
> > +
> > + /* Auxillary Expansion GPIOs */
> > + if (!minnow_lvds_detect()) {
> > + pr_debug("LVDS_DETECT not asserted, configuring Aux GPIO
> > lines\n");
> > + err = gpio_request_array(expansion_aux_gpios,
> > + ARRAY_SIZE(expansion_aux_gpios));
> > + if (err) {
> > + pr_err("Failed to request expansion aux GPIO lines\n");
> > + goto out;
> > + }
> > + } else {
> > + pr_debug("LVDS_DETECT asserted, ignoring aux GPIO lines\n");
> > + }
> > +
> > + /* Expansion GPIOs */
> > + err = gpio_request_array(expansion_gpios, ARRAY_SIZE(expansion_gpios));
> > + if (err) {
> > + pr_err("Failed to request expansion GPIO lines\n");
> > + if (minnow_lvds_detect())
> > + gpio_free_array(expansion_aux_gpios,
> > + ARRAY_SIZE(expansion_aux_gpios));
> > + goto out;
> > + }
> > +
> > + out:
> > + return err;
>
> Are you planning to add something else to 'out' path?
> Otherwise I think it will look better if you do return instead of
> [useless] gotos.
I suppose this is a matter of preference. I am allergic to multiple
return points. However, your argument is consistent with CodingStyle
Chapter 7 in that it states "and some common work such as cleanup has to
be done." If that "and" is a required sort of &&, then I should change
it. Do others have a strong opinion here?
--
Darren Hart
Intel Open Source Technology Center
Yocto Project - Technical Lead - Linux Kernel
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