diff options
| -rw-r--r-- | drivers/video/backlight/pwm_bl.c | 15 | ||||
| -rw-r--r-- | include/linux/kernel.h | 1 | ||||
| -rw-r--r-- | lib/math/Makefile | 2 | ||||
| -rw-r--r-- | lib/math/int_pow.c | 32 |
4 files changed, 34 insertions, 16 deletions
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 53b8ceea9bde..fb45f866b923 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -155,21 +155,6 @@ static const struct backlight_ops pwm_backlight_ops = { #ifdef CONFIG_OF #define PWM_LUMINANCE_SCALE 10000 /* luminance scale */ -/* An integer based power function */ -static u64 int_pow(u64 base, int exp) -{ - u64 result = 1; - - while (exp) { - if (exp & 1) - result *= base; - exp >>= 1; - base *= base; - } - - return result; -} - /* * CIE lightness to PWM conversion. * diff --git a/include/linux/kernel.h b/include/linux/kernel.h index a3b59d143afb..74b1ee9027f5 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -484,6 +484,7 @@ extern int __kernel_text_address(unsigned long addr); extern int kernel_text_address(unsigned long addr); extern int func_ptr_is_kernel_text(void *ptr); +u64 int_pow(u64 base, unsigned int exp); unsigned long int_sqrt(unsigned long); #if BITS_PER_LONG < 64 diff --git a/lib/math/Makefile b/lib/math/Makefile index b75878420da6..583bbfebfc09 100644 --- a/lib/math/Makefile +++ b/lib/math/Makefile @@ -1,4 +1,4 @@ -obj-y += div64.o gcd.o lcm.o int_sqrt.o reciprocal_div.o +obj-y += div64.o gcd.o lcm.o int_pow.o int_sqrt.o reciprocal_div.o obj-$(CONFIG_CORDIC) += cordic.o obj-$(CONFIG_PRIME_NUMBERS) += prime_numbers.o diff --git a/lib/math/int_pow.c b/lib/math/int_pow.c new file mode 100644 index 000000000000..622fc1ab3c74 --- /dev/null +++ b/lib/math/int_pow.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * An integer based power function + * + * Derived from drivers/video/backlight/pwm_bl.c + */ + +#include <linux/export.h> +#include <linux/kernel.h> +#include <linux/types.h> + +/** + * int_pow - computes the exponentiation of the given base and exponent + * @base: base which will be raised to the given power + * @exp: power to be raised to + * + * Computes: pow(base, exp), i.e. @base raised to the @exp power + */ +u64 int_pow(u64 base, unsigned int exp) +{ + u64 result = 1; + + while (exp) { + if (exp & 1) + result *= base; + exp >>= 1; + base *= base; + } + + return result; +} +EXPORT_SYMBOL_GPL(int_pow); |