diff mbox series

[2/3] docs: hwmon: (ltc2945): change type of val to ULL in ltc2945_val_to_reg()

Message ID 20201106101825.30960-2-alexandru.ardelean@analog.com (mailing list archive)
State Changes Requested
Headers show
Series [1/3] hwmon: (ltc2945): wrap regmap into an ltc2945_state struct | expand

Commit Message

Alexandru Ardelean Nov. 6, 2020, 10:18 a.m. UTC 
In order to account for any potential overflows that could occur.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
 drivers/hwmon/ltc2945.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

Comments

Guenter Roeck Nov. 6, 2020, 1:14 p.m. UTC | #1 
On Fri, Nov 06, 2020 at 12:18:24PM +0200, Alexandru Ardelean wrote:
> In order to account for any potential overflows that could occur.
> 
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> ---
>  drivers/hwmon/ltc2945.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/hwmon/ltc2945.c b/drivers/hwmon/ltc2945.c
> index 1cea710df668..75d997d31e01 100644
> --- a/drivers/hwmon/ltc2945.c
> +++ b/drivers/hwmon/ltc2945.c
> @@ -155,7 +155,7 @@ static long long ltc2945_reg_to_val(struct device *dev, u8 reg)
>  }
>  
>  static int ltc2945_val_to_reg(struct device *dev, u8 reg,
> -			      unsigned long val)
> +			      unsigned long long val)
>  {
>  	struct ltc2945_state *st = dev_get_drvdata(dev);
>  	struct regmap *regmap = st->regmap;
> @@ -181,14 +181,14 @@ static int ltc2945_val_to_reg(struct device *dev, u8 reg,
>  			return ret;
>  		if (control & CONTROL_MULT_SELECT) {
>  			/* 25 mV * 25 uV = 0.625 uV resolution. */
> -			val = DIV_ROUND_CLOSEST(val, 625);
> +			val = DIV_ROUND_CLOSEST_ULL(val, 625);
>  		} else {
>  			/*
>  			 * 0.5 mV * 25 uV = 0.0125 uV resolution.
>  			 * Divide first to avoid overflow;
>  			 * accept loss of accuracy.
>  			 */
> -			val = DIV_ROUND_CLOSEST(val, 25) * 2;
> +			val = DIV_ROUND_CLOSEST_ULL(val, 25) * 2;
>  		}
>  		break;
>  	case LTC2945_VIN_H:
> @@ -197,7 +197,7 @@ static int ltc2945_val_to_reg(struct device *dev, u8 reg,
>  	case LTC2945_MAX_VIN_THRES_H:
>  	case LTC2945_MIN_VIN_THRES_H:
>  		/* 25 mV resolution. */
> -		val /= 25;
> +		val = div_u64(val, 25);
>  		break;
>  	case LTC2945_ADIN_H:
>  	case LTC2945_MAX_ADIN_H:
> @@ -219,7 +219,7 @@ static int ltc2945_val_to_reg(struct device *dev, u8 reg,
>  		 * dividing the reported current by the sense resistor value
>  		 * in mOhm.
>  		 */
> -		val = DIV_ROUND_CLOSEST(val, 25);
> +		val = DIV_ROUND_CLOSEST_ULL(val, 25);
>  		break;
>  	default:
>  		return -EINVAL;
> @@ -247,13 +247,13 @@ static ssize_t ltc2945_value_store(struct device *dev,
>  	struct ltc2945_state *st = dev_get_drvdata(dev);
>  	struct regmap *regmap = st->regmap;
>  	u8 reg = attr->index;
> -	unsigned long val;
> +	unsigned long long val;
>  	u8 regbuf[3];
>  	int num_regs;
>  	int regval;
>  	int ret;
>  
> -	ret = kstrtoul(buf, 10, &val);
> +	ret = kstrtoull(buf, 10, &val);

This part of the change is unnecessary. Just keep 'val' as-is.
ltc2945_val_to_reg() can still accept ull.

Guenter

>  	if (ret)
>  		return ret;
>  
> -- 
> 2.27.0
>
Alexandru Ardelean Nov. 9, 2020, 6:38 a.m. UTC | #2 
On Fri, Nov 6, 2020 at 3:14 PM Guenter Roeck <linux@roeck-us.net> wrote:
>
> On Fri, Nov 06, 2020 at 12:18:24PM +0200, Alexandru Ardelean wrote:
> > In order to account for any potential overflows that could occur.
> >
> > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> > ---
> >  drivers/hwmon/ltc2945.c | 14 +++++++-------
> >  1 file changed, 7 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/hwmon/ltc2945.c b/drivers/hwmon/ltc2945.c
> > index 1cea710df668..75d997d31e01 100644
> > --- a/drivers/hwmon/ltc2945.c
> > +++ b/drivers/hwmon/ltc2945.c
> > @@ -155,7 +155,7 @@ static long long ltc2945_reg_to_val(struct device *dev, u8 reg)
> >  }
> >
> >  static int ltc2945_val_to_reg(struct device *dev, u8 reg,
> > -                           unsigned long val)
> > +                           unsigned long long val)
> >  {
> >       struct ltc2945_state *st = dev_get_drvdata(dev);
> >       struct regmap *regmap = st->regmap;
> > @@ -181,14 +181,14 @@ static int ltc2945_val_to_reg(struct device *dev, u8 reg,
> >                       return ret;
> >               if (control & CONTROL_MULT_SELECT) {
> >                       /* 25 mV * 25 uV = 0.625 uV resolution. */
> > -                     val = DIV_ROUND_CLOSEST(val, 625);
> > +                     val = DIV_ROUND_CLOSEST_ULL(val, 625);
> >               } else {
> >                       /*
> >                        * 0.5 mV * 25 uV = 0.0125 uV resolution.
> >                        * Divide first to avoid overflow;
> >                        * accept loss of accuracy.
> >                        */
> > -                     val = DIV_ROUND_CLOSEST(val, 25) * 2;
> > +                     val = DIV_ROUND_CLOSEST_ULL(val, 25) * 2;
> >               }
> >               break;
> >       case LTC2945_VIN_H:
> > @@ -197,7 +197,7 @@ static int ltc2945_val_to_reg(struct device *dev, u8 reg,
> >       case LTC2945_MAX_VIN_THRES_H:
> >       case LTC2945_MIN_VIN_THRES_H:
> >               /* 25 mV resolution. */
> > -             val /= 25;
> > +             val = div_u64(val, 25);
> >               break;
> >       case LTC2945_ADIN_H:
> >       case LTC2945_MAX_ADIN_H:
> > @@ -219,7 +219,7 @@ static int ltc2945_val_to_reg(struct device *dev, u8 reg,
> >                * dividing the reported current by the sense resistor value
> >                * in mOhm.
> >                */
> > -             val = DIV_ROUND_CLOSEST(val, 25);
> > +             val = DIV_ROUND_CLOSEST_ULL(val, 25);
> >               break;
> >       default:
> >               return -EINVAL;
> > @@ -247,13 +247,13 @@ static ssize_t ltc2945_value_store(struct device *dev,
> >       struct ltc2945_state *st = dev_get_drvdata(dev);
> >       struct regmap *regmap = st->regmap;
> >       u8 reg = attr->index;
> > -     unsigned long val;
> > +     unsigned long long val;
> >       u8 regbuf[3];
> >       int num_regs;
> >       int regval;
> >       int ret;
> >
> > -     ret = kstrtoul(buf, 10, &val);
> > +     ret = kstrtoull(buf, 10, &val);
>
> This part of the change is unnecessary. Just keep 'val' as-is.
> ltc2945_val_to_reg() can still accept ull.

Ack

>
> Guenter
>
> >       if (ret)
> >               return ret;
> >
> > --
> > 2.27.0
> >
diff mbox series

Patch

diff --git a/drivers/hwmon/ltc2945.c b/drivers/hwmon/ltc2945.c
index 1cea710df668..75d997d31e01 100644
--- a/drivers/hwmon/ltc2945.c
+++ b/drivers/hwmon/ltc2945.c
@@ -155,7 +155,7 @@  static long long ltc2945_reg_to_val(struct device *dev, u8 reg)
 }
 
 static int ltc2945_val_to_reg(struct device *dev, u8 reg,
-			      unsigned long val)
+			      unsigned long long val)
 {
 	struct ltc2945_state *st = dev_get_drvdata(dev);
 	struct regmap *regmap = st->regmap;
@@ -181,14 +181,14 @@  static int ltc2945_val_to_reg(struct device *dev, u8 reg,
 			return ret;
 		if (control & CONTROL_MULT_SELECT) {
 			/* 25 mV * 25 uV = 0.625 uV resolution. */
-			val = DIV_ROUND_CLOSEST(val, 625);
+			val = DIV_ROUND_CLOSEST_ULL(val, 625);
 		} else {
 			/*
 			 * 0.5 mV * 25 uV = 0.0125 uV resolution.
 			 * Divide first to avoid overflow;
 			 * accept loss of accuracy.
 			 */
-			val = DIV_ROUND_CLOSEST(val, 25) * 2;
+			val = DIV_ROUND_CLOSEST_ULL(val, 25) * 2;
 		}
 		break;
 	case LTC2945_VIN_H:
@@ -197,7 +197,7 @@  static int ltc2945_val_to_reg(struct device *dev, u8 reg,
 	case LTC2945_MAX_VIN_THRES_H:
 	case LTC2945_MIN_VIN_THRES_H:
 		/* 25 mV resolution. */
-		val /= 25;
+		val = div_u64(val, 25);
 		break;
 	case LTC2945_ADIN_H:
 	case LTC2945_MAX_ADIN_H:
@@ -219,7 +219,7 @@  static int ltc2945_val_to_reg(struct device *dev, u8 reg,
 		 * dividing the reported current by the sense resistor value
 		 * in mOhm.
 		 */
-		val = DIV_ROUND_CLOSEST(val, 25);
+		val = DIV_ROUND_CLOSEST_ULL(val, 25);
 		break;
 	default:
 		return -EINVAL;
@@ -247,13 +247,13 @@  static ssize_t ltc2945_value_store(struct device *dev,
 	struct ltc2945_state *st = dev_get_drvdata(dev);
 	struct regmap *regmap = st->regmap;
 	u8 reg = attr->index;
-	unsigned long val;
+	unsigned long long val;
 	u8 regbuf[3];
 	int num_regs;
 	int regval;
 	int ret;
 
-	ret = kstrtoul(buf, 10, &val);
+	ret = kstrtoull(buf, 10, &val);
 	if (ret)
 		return ret;