On Tue, 13 Aug 2019 17:43:15 +0300
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> On Sat, Jun 22, 2019 at 10:06:42AM +0100, Jonathan Cameron wrote:
> > On Wed, 19 Jun 2019 17:07:02 +0300
> > Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> >
> > > Instead of linear approach to calculate power of 10, use generic int_pow()
> > > which does it better.
> > >
> > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> > Hi Andy,
> >
> > Looks good to me, but I would like Srinivas to take a look and
> > preferably test this a bit just to check we aren't all missing something
> > subtle!
> >
> > +CC Srinivas
>
> Srinivas, do you have any comments on this?
I think Srinivas got dropped from your CC list for some reason.
Anyhow, it's been a while so let's conclude Srinivas is busy and
rely on it being as obviously correct as it seems to be ;)
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.
Thanks,
Jonathan
>
> >
> > Thanks,
> >
> > Jonathan
> > > ---
> > > .../hid-sensors/hid-sensor-attributes.c | 53 ++++++++-----------
> > > 1 file changed, 22 insertions(+), 31 deletions(-)
> > >
> > > diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > index a8a3fe428d8d..b9dd19b34267 100644
> > > --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > @@ -8,6 +8,7 @@
> > > #include <linux/module.h>
> > > #include <linux/interrupt.h>
> > > #include <linux/irq.h>
> > > +#include <linux/kernel.h>
> > > #include <linux/slab.h>
> > > #include <linux/hid-sensor-hub.h>
> > > #include <linux/iio/iio.h>
> > > @@ -68,16 +69,6 @@ static struct {
> > > {HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
> > > };
> > >
> > > -static int pow_10(unsigned power)
> > > -{
> > > - int i;
> > > - int ret = 1;
> > > - for (i = 0; i < power; ++i)
> > > - ret = ret * 10;
> > > -
> > > - return ret;
> > > -}
> > > -
> > > static void simple_div(int dividend, int divisor, int *whole,
> > > int *micro_frac)
> > > {
> > > @@ -96,14 +87,14 @@ static void simple_div(int dividend, int divisor, int *whole,
> > > rem *= 10;
> > > exp++;
> > > }
> > > - *micro_frac = (rem / divisor) * pow_10(6-exp);
> > > + *micro_frac = (rem / divisor) * int_pow(10, 6 - exp);
> > > }
> > > }
> > >
> > > static void split_micro_fraction(unsigned int no, int exp, int *val1, int *val2)
> > > {
> > > - *val1 = no/pow_10(exp);
> > > - *val2 = no%pow_10(exp) * pow_10(6-exp);
> > > + *val1 = no / int_pow(10, exp);
> > > + *val2 = no % int_pow(10, exp) * int_pow(10, 6 - exp);
> > > }
> > >
> > > /*
> > > @@ -125,7 +116,7 @@ static void convert_from_vtf_format(u32 value, int size, int exp,
> > > }
> > > exp = hid_sensor_convert_exponent(exp);
> > > if (exp >= 0) {
> > > - *val1 = sign * value * pow_10(exp);
> > > + *val1 = sign * value * int_pow(10, exp);
> > > *val2 = 0;
> > > } else {
> > > split_micro_fraction(value, -exp, val1, val2);
> > > @@ -145,10 +136,10 @@ static u32 convert_to_vtf_format(int size, int exp, int val1, int val2)
> > > sign = -1;
> > > exp = hid_sensor_convert_exponent(exp);
> > > if (exp < 0) {
> > > - value = abs(val1) * pow_10(-exp);
> > > - value += abs(val2) / pow_10(6+exp);
> > > + value = abs(val1) * int_pow(10, -exp);
> > > + value += abs(val2) / int_pow(10, 6 + exp);
> > > } else
> > > - value = abs(val1) / pow_10(exp);
> > > + value = abs(val1) / int_pow(10, exp);
> > > if (sign < 0)
> > > value = ((1LL << (size * 8)) - value);
> > >
> > > @@ -211,12 +202,12 @@ int hid_sensor_write_samp_freq_value(struct hid_sensor_common *st,
> > > if (val1 < 0 || val2 < 0)
> > > return -EINVAL;
> > >
> > > - value = val1 * pow_10(6) + val2;
> > > + value = val1 * int_pow(10, 6) + val2;
> > > if (value) {
> > > if (st->poll.units == HID_USAGE_SENSOR_UNITS_MILLISECOND)
> > > - value = pow_10(9)/value;
> > > + value = int_pow(10, 9) / value;
> > > else if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)
> > > - value = pow_10(6)/value;
> > > + value = int_pow(10, 6) / value;
> > > else
> > > value = 0;
> > > }
> > > @@ -311,34 +302,34 @@ static void adjust_exponent_nano(int *val0, int *val1, int scale0,
> > > int rem;
> > >
> > > if (exp > 0) {
> > > - *val0 = scale0 * pow_10(exp);
> > > + *val0 = scale0 * int_pow(10, exp);
> > > res = 0;
> > > if (exp > 9) {
> > > *val1 = 0;
> > > return;
> > > }
> > > for (i = 0; i < exp; ++i) {
> > > - x = scale1 / pow_10(8 - i);
> > > - res += (pow_10(exp - 1 - i) * x);
> > > - scale1 = scale1 % pow_10(8 - i);
> > > + x = scale1 / int_pow(10, 8 - i);
> > > + res += int_pow(10, exp - 1 - i) * x;
> > > + scale1 = scale1 % int_pow(10, 8 - i);
> > > }
> > > *val0 += res;
> > > - *val1 = scale1 * pow_10(exp);
> > > + *val1 = scale1 * int_pow(10, exp);
> > > } else if (exp < 0) {
> > > exp = abs(exp);
> > > if (exp > 9) {
> > > *val0 = *val1 = 0;
> > > return;
> > > }
> > > - *val0 = scale0 / pow_10(exp);
> > > - rem = scale0 % pow_10(exp);
> > > + *val0 = scale0 / int_pow(10, exp);
> > > + rem = scale0 % int_pow(10, exp);
> > > res = 0;
> > > for (i = 0; i < (9 - exp); ++i) {
> > > - x = scale1 / pow_10(8 - i);
> > > - res += (pow_10(8 - exp - i) * x);
> > > - scale1 = scale1 % pow_10(8 - i);
> > > + x = scale1 / int_pow(10, 8 - i);
> > > + res += int_pow(10, 8 - exp - i) * x;
> > > + scale1 = scale1 % int_pow(10, 8 - i);
> > > }
> > > - *val1 = rem * pow_10(9 - exp) + res;
> > > + *val1 = rem * int_pow(10, 9 - exp) + res;
> > > } else {
> > > *val0 = scale0;
> > > *val1 = scale1;
> >
>
