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@xxxxxxxxx>
---
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
