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iio: hid-sensor-attributes: Convert to use int_pow() 

Instead of linear approach to calculate power of 10, use generic int_pow()
which does it better.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
alistair/sunxi64-5.4-dsi
Andy Shevchenko 2019-06-19 17:07:02 +03:00 committed by Jonathan Cameron
parent 2715a28105
commit 473d12f763
1 changed files with 22 additions and 31 deletions
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53
drivers/iio/common/hid-sensors/hid-sensor-attributes.c
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@ -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;