linux-kernel - Re: [RFC PATCH 3/4] pinctrl: at91: improve pinconf_set/get function robustness

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Date:	Sat, 14 Sep 2013 18:55:25 +0200
From:	Jean-Christophe PLAGNIOL-VILLARD <plagnioj@...osoft.com>
To:	Boris BREZILLON <b.brezillon@...rkiz.com>
Cc:	Rob Herring <rob.herring@...xeda.com>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Stephen Warren <swarren@...dotorg.org>,
	Ian Campbell <ian.campbell@...rix.com>,
	Rob Landley <rob@...dley.net>,
	Linus Walleij <linus.walleij@...aro.org>,
	Grant Likely <grant.likely@...aro.org>,
	Nicolas Ferre <nicolas.ferre@...el.com>,
	Richard Genoud <richard.genoud@...il.com>,
	Jiri Kosina <jkosina@...e.cz>, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-doc@...r.kernel.org
Subject: Re: [RFC PATCH 3/4] pinctrl: at91: improve pinconf_set/get function
 robustness

On 09:49 Fri 13 Sep     , Boris BREZILLON wrote:
> Reset caller's config variable before setting current config flags to avoid
> erronous config return.
> 
> DEBOUNCE and DEGLITCH options are mutually exclusive. Return an error if they
> are both defined in the config.
> Do not call set_deglitch if DEBOUNCE is enabled to avoid reseting the IFSR
> register (which will result in disabling the debounce filter).
> 
> Signed-off-by: Boris BREZILLON <b.brezillon@...rkiz.com>
> ---
>  drivers/pinctrl/pinctrl-at91.c |   18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pinctrl/pinctrl-at91.c b/drivers/pinctrl/pinctrl-at91.c
> index 6624bce..ac9dbea 100644
> --- a/drivers/pinctrl/pinctrl-at91.c
> +++ b/drivers/pinctrl/pinctrl-at91.c
> @@ -724,6 +724,7 @@ static int at91_pinconf_get(struct pinctrl_dev *pctldev,
>  	dev_dbg(info->dev, "%s:%d, pin_id=%d, config=0x%lx", __func__, __LINE__, pin_id, *config);
>  	pio = pin_to_controller(info, pin_to_bank(pin_id));
>  	pin = pin_id % MAX_NB_GPIO_PER_BANK;
> +	*config = 0;
>  
>  	if (at91_mux_get_multidrive(pio, pin))
>  		*config |= MULTI_DRIVE;
> @@ -757,13 +758,20 @@ static int at91_pinconf_set(struct pinctrl_dev *pctldev,
>  	if (config & PULL_UP && config & PULL_DOWN)
>  		return -EINVAL;
>  
> -	at91_mux_set_pullup(pio, mask, config & PULL_UP);
> -	at91_mux_set_multidrive(pio, mask, config & MULTI_DRIVE);
> -	if (info->ops->set_deglitch)
> -		info->ops->set_deglitch(pio, mask, config & DEGLITCH);
> -	if (info->ops->set_debounce)
> +	if (config & DEBOUNCE && config & DEGLITCH)
> +		return -EINVAL;
here ok
> +
> +	if (config & DEBOUNCE) {
> +		if (!info->ops->set_debounce)
> +			return -ENOTSUPP;
a warning is better here than an error
> +
>  		info->ops->set_debounce(pio, mask, config & DEBOUNCE,
>  				(config & DEBOUNCE_VAL) >> DEBOUNCE_VAL_SHIFT);
> +	} else if (info->ops->set_deglitch)
> +		info->ops->set_deglitch(pio, mask, config & DEGLITCH);
> +


> +	at91_mux_set_pullup(pio, mask, config & PULL_UP);
> +	at91_mux_set_multidrive(pio, mask, config & MULTI_DRIVE);

>  	if (info->ops->set_pulldown)
>  		info->ops->set_pulldown(pio, mask, config & PULL_DOWN);
>  	if (info->ops->disable_schmitt_trig && config & DIS_SCHMIT)
> -- 
> 1.7.9.5
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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