| Message ID | 20190507193504.28248-2-f.fainelli@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | hwmon: scmi: Scale values to target desired HWMON units | expand |
On Tue, May 07, 2019 at 12:35:02PM -0700, Florian Fainelli wrote: > Provide a simple macro that can return the value of 10 raised to a > positive integer. We are going to use this in order to scale units from > firmware to HWMON. > > Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> > --- > include/linux/kernel.h | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/include/linux/kernel.h b/include/linux/kernel.h > index 2d14e21c16c0..62fc8bd84bc9 100644 > --- a/include/linux/kernel.h > +++ b/include/linux/kernel.h > @@ -294,6 +294,17 @@ static inline u32 reciprocal_scale(u32 val, u32 ep_ro) > return (u32)(((u64) val * ep_ro) >> 32); > } > > +/* Return in f the value of 10 raise to the power x */ > +#define __pow10(x, f)( \ > +{ \ > + typeof(x) __x = abs(x); \ > + f = 1; \ > + while (__x--) \ > + f *= 10; \ > + f; \ > +} \ > +) Kind of unusual. I would have expected to use this like f = __pow10(x); ie without having to provide f as parameter. That would be much less confusing. I assume this is to make the result type independent, but I am not sure if that is worth the trouble. Are there users outside the hwmon code ? If not, it might be simpler to keep it there for now. Thanks, Guenter > + > #if defined(CONFIG_MMU) && \ > (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)) > #define might_fault() __might_fault(__FILE__, __LINE__) > -- > 2.17.1 >
On 5/7/19 2:06 PM, Guenter Roeck wrote: > On Tue, May 07, 2019 at 12:35:02PM -0700, Florian Fainelli wrote: >> Provide a simple macro that can return the value of 10 raised to a >> positive integer. We are going to use this in order to scale units from >> firmware to HWMON. >> >> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> >> --- >> include/linux/kernel.h | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> diff --git a/include/linux/kernel.h b/include/linux/kernel.h >> index 2d14e21c16c0..62fc8bd84bc9 100644 >> --- a/include/linux/kernel.h >> +++ b/include/linux/kernel.h >> @@ -294,6 +294,17 @@ static inline u32 reciprocal_scale(u32 val, u32 ep_ro) >> return (u32)(((u64) val * ep_ro) >> 32); >> } >> >> +/* Return in f the value of 10 raise to the power x */ >> +#define __pow10(x, f)( \ >> +{ \ >> + typeof(x) __x = abs(x); \ >> + f = 1; \ >> + while (__x--) \ >> + f *= 10; \ >> + f; \ >> +} \ >> +) > > Kind of unusual. I would have expected to use this like > f = __pow10(x); > ie without having to provide f as parameter. That would be much less > confusing. I assume this is to make the result type independent, but > I am not sure if that is worth the trouble. Correct, that was the intent here. > > Are there users outside the hwmon code ? If not, it might be simpler > to keep it there for now. There appears to be a few outside actually: drivers/acpi/sbs.c::battery_scale drivers/iio/common/hid-sensors/hid-sensor-attributes.c::pow_10 There could be others but those two came out as obvious candidates. Would you be okay with a local pow10 function within scmi-hwmon.c and a subsequent patch series providing a common function?
On 5/7/19 2:49 PM, Florian Fainelli wrote: > On 5/7/19 2:06 PM, Guenter Roeck wrote: >> On Tue, May 07, 2019 at 12:35:02PM -0700, Florian Fainelli wrote: >>> Provide a simple macro that can return the value of 10 raised to a >>> positive integer. We are going to use this in order to scale units from >>> firmware to HWMON. >>> >>> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> >>> --- >>> include/linux/kernel.h | 11 +++++++++++ >>> 1 file changed, 11 insertions(+) >>> >>> diff --git a/include/linux/kernel.h b/include/linux/kernel.h >>> index 2d14e21c16c0..62fc8bd84bc9 100644 >>> --- a/include/linux/kernel.h >>> +++ b/include/linux/kernel.h >>> @@ -294,6 +294,17 @@ static inline u32 reciprocal_scale(u32 val, u32 ep_ro) >>> return (u32)(((u64) val * ep_ro) >> 32); >>> } >>> >>> +/* Return in f the value of 10 raise to the power x */ >>> +#define __pow10(x, f)( \ >>> +{ \ >>> + typeof(x) __x = abs(x); \ >>> + f = 1; \ >>> + while (__x--) \ >>> + f *= 10; \ >>> + f; \ >>> +} \ >>> +) >> >> Kind of unusual. I would have expected to use this like >> f = __pow10(x); >> ie without having to provide f as parameter. That would be much less >> confusing. I assume this is to make the result type independent, but >> I am not sure if that is worth the trouble. > > Correct, that was the intent here. > >> >> Are there users outside the hwmon code ? If not, it might be simpler >> to keep it there for now. > > There appears to be a few outside actually: > > drivers/acpi/sbs.c::battery_scale > drivers/iio/common/hid-sensors/hid-sensor-attributes.c::pow_10 > > There could be others but those two came out as obvious candidates. > > Would you be okay with a local pow10 function within scmi-hwmon.c and a > subsequent patch series providing a common function? > I would prefer that, actually, to reduce dependencies. Thanks, Guenter
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 2d14e21c16c0..62fc8bd84bc9 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -294,6 +294,17 @@ static inline u32 reciprocal_scale(u32 val, u32 ep_ro) return (u32)(((u64) val * ep_ro) >> 32); } +/* Return in f the value of 10 raise to the power x */ +#define __pow10(x, f)( \ +{ \ + typeof(x) __x = abs(x); \ + f = 1; \ + while (__x--) \ + f *= 10; \ + f; \ +} \ +) + #if defined(CONFIG_MMU) && \ (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)) #define might_fault() __might_fault(__FILE__, __LINE__)
Provide a simple macro that can return the value of 10 raised to a positive integer. We are going to use this in order to scale units from firmware to HWMON. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> --- include/linux/kernel.h | 11 +++++++++++ 1 file changed, 11 insertions(+)