realtek-rtl8188eus-dkms/hal/phydm/phydm_math_lib.c

/******************************************************************************
 *
 * Copyright(c) 2007 - 2017  Realtek Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 * Contact Information:
 * wlanfae <wlanfae@realtek.com>
 * Realtek Corporation, No. 2, Innovation Road II, Hsinchu Science Park,
 * Hsinchu 300, Taiwan.
 *
 * Larry Finger <Larry.Finger@lwfinger.net>
 *
 *****************************************************************************/

/* ************************************************************
 * include files
 * ************************************************************ */

#include "mp_precomp.h"
#include "phydm_precomp.h"

const u16 db_invert_table[12][8] = {
	{	1,		1,		1,		2,		2,		2,		2,		3},
	{	3,		3,		4,		4,		4,		5,		6,		6},
	{	7,		8,		9,		10,		11,		13,		14,		16},
	{	18,		20,		22,		25,		28,		32,		35,		40},
	{	45,		50,		56,		63,		71,		79,		89,		100},
	{	112,		126,		141,		158,		178,		200,		224,		251},
	{	282,		316,		355,		398,		447,		501,		562,		631},
	{	708,		794,		891,		1000,	1122,	1259,	1413,	1585},
	{	1778,	1995,	2239,	2512,	2818,	3162,	3548,	3981},
	{	4467,	5012,	5623,	6310,	7079,	7943,	8913,	10000},
	{	11220,	12589,	14125,	15849,	17783,	19953,	22387,	25119},
	{	28184,	31623,	35481,	39811,	44668,	50119,	56234,	65535}
};


/*Y = 10*log(X)*/
s32
odm_pwdb_conversion(
	s32 X,
	u32 total_bit,
	u32 decimal_bit
)
{
	s32 Y, integer = 0, decimal = 0;
	u32 i;

	if (X == 0)
		X = 1; /* log2(x), x can't be 0 */

	for (i = (total_bit - 1); i > 0; i--) {
		if (X & BIT(i)) {
			integer = i;
			if (i > 0)
				decimal = (X & BIT(i - 1)) ? 2 : 0; /* decimal is 0.5dB*3=1.5dB~=2dB */
			break;
		}
	}

	Y = 3 * (integer - decimal_bit) + decimal; /* 10*log(x)=3*log2(x), */

	return Y;
}

s32
odm_sign_conversion(
	s32 value,
	u32 total_bit
)
{
	if (value & BIT(total_bit - 1))
		value -= BIT(total_bit);
	
	return value;
}

void
phydm_seq_sorting(
	void	*dm_void,
	u32	*value,
	u32	*rank_idx,
	u32	*idx_out,
	u8	seq_length
)
{
	u8		i = 0, j = 0;
	u32		tmp_a, tmp_b;
	u32		tmp_idx_a, tmp_idx_b;

	for (i = 0; i < seq_length; i++) {
		rank_idx[i] = i;
		/**/
	}

	for (i = 0; i < (seq_length - 1); i++) {
		for (j = 0; j < (seq_length - 1 - i); j++) {
			tmp_a = value[j];
			tmp_b = value[j + 1];

			tmp_idx_a = rank_idx[j];
			tmp_idx_b = rank_idx[j + 1];

			if (tmp_a < tmp_b) {
				value[j] = tmp_b;
				value[j + 1] = tmp_a;

				rank_idx[j] = tmp_idx_b;
				rank_idx[j + 1] = tmp_idx_a;
			}
		}
	}

	for (i = 0; i < seq_length; i++) {
		idx_out[rank_idx[i]] = i + 1;
		/**/
	}
}

u32
odm_convert_to_db(
	u32	value)
{
	u8 i;
	u8 j;
	u32 dB;

	value = value & 0xFFFF;

	for (i = 0; i < 12; i++) {
		if (value <= db_invert_table[i][7])
			break;
	}

	if (i >= 12) {
		return 96;	/* maximum 96 dB */
	}

	for (j = 0; j < 8; j++) {
		if (value <= db_invert_table[i][j])
			break;
	}

	dB = (i << 3) + j + 1;

	return dB;
}

u32
odm_convert_to_linear(
	u32	value)
{
	u8 i;
	u8 j;
	u32 linear;

	/* 1dB~96dB */

	value = value & 0xFF;

	i = (u8)((value - 1) >> 3);
	j = (u8)(value - 1) - (i << 3);

	linear = db_invert_table[i][j];

	return linear;
}