Subject: Re: [PATCH RESEND] gpio: mpc8xxx: don't allow input-only pins to be output for MPC5121

From: Wolfram Sang <[email-masked]>
Date: Tue, 13 Dec 2011 19:23:07 +0100

On Tue, Dec 13, 2011 at 11:16:59AM -0700, Grant Likely wrote:
> On Tue, Dec 13, 2011 at 10:12:48AM +0100, Wolfram Sang wrote:
> > Add a 5121-custom reject if an input-only pin is requested to be output
> > (see 18.3.1.1 in the refman). Also, rewrite mach-specific quirk setup to
> > consume less lines which scales better.
> > 
> > Signed-off-by: Wolfram Sang <[email-masked]>
> > ---
> >  drivers/gpio/gpio-mpc8xxx.c |   17 ++++++++++++-----
> >  1 files changed, 12 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/gpio/gpio-mpc8xxx.c b/drivers/gpio/gpio-mpc8xxx.c
> > index ec3fcf0..25dc736 100644
> > --- a/drivers/gpio/gpio-mpc8xxx.c
> > +++ b/drivers/gpio/gpio-mpc8xxx.c
> > @@ -115,6 +115,14 @@ static int mpc8xxx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
> >  	return 0;
> >  }
> >  
> > +static int mpc5121_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
> > +{
> > +	/* GPIO 28..31 are input only on MPC5121 */
> > +	if (gpio >= 28)
> > +		return -EINVAL;
> > +
> > +	return mpc8xxx_gpio_dir_out(gc, gpio, val);
> > +}
> >  static int mpc8xxx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
> 
> This actually caused a build failure.  mpc8xxx_gpio_dir_out() was used before
> it was declared.  I moved the symbol to immediately below and applied anyway,
> but how did it compile for you?  Should I drop this patch until you retest?

Huh, I am surprised as well. Will investigate tomorrow. Sorry for the
inconvenience.

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