Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2)  * dvb-math provides some complex fixed-point math
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * operations shared between the dvb related stuff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * Copyright (C) 2006 Christoph Pfister (christophpfister@gmail.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  * This library is free software; you can redistribute it and/or modify
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  * it under the terms of the GNU Lesser General Public License as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  * published by the Free Software Foundation; either version 2.1 of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  * the License, or (at your option) any later version.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  * This program is distributed in the hope that it will be useful,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  * but WITHOUT ANY WARRANTY; without even the implied warranty of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  * GNU Lesser General Public License for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #ifndef __DVB_MATH_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #define __DVB_MATH_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)  * intlog2 - computes log2 of a value; the result is shifted left by 24 bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)  * @value: The value (must be != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)  * to use rational values you can use the following method:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)  *   intlog2(value) = intlog2(value * 2^x) - x * 2^24
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)  * Some usecase examples:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)  *	intlog2(8) will give 3 << 24 = 3 * 2^24
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)  *	intlog2(9) will give 3 << 24 + ... = 3.16... * 2^24
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)  *	intlog2(1.5) = intlog2(3) - 2^24 = 0.584... * 2^24
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)  * return: log2(value) * 2^24
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) extern unsigned int intlog2(u32 value);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)  * intlog10 - computes log10 of a value; the result is shifted left by 24 bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)  * @value: The value (must be != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)  * to use rational values you can use the following method:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)  *   intlog10(value) = intlog10(value * 10^x) - x * 2^24
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)  * An usecase example:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)  *	intlog10(1000) will give 3 << 24 = 3 * 2^24
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)  *   due to the implementation intlog10(1000) might be not exactly 3 * 2^24
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)  * look at intlog2 for similar examples
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)  * return: log10(value) * 2^24
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) extern unsigned int intlog10(u32 value);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) #endif