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

[Alexandru Ardelean]

On Fri, Nov 6, 2020 at 3:14 PM Guenter Roeck  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 
> > ---
> >  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, );
> > + ret = kstrtoull(buf, 10, );
>
> 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
> >

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

[Guenter Roeck]

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 
> ---
>  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, );
> + ret = kstrtoull(buf, 10, );

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
>