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

From: Grant Likely <[email-masked]>
Date: Tue, 13 Dec 2011 11:16:59 -0700

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?

g.