drivers/gpu/drm/omapdrm/dss/dispc_coefs.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2011 Texas Instruments Incorporated - https://www.ti.com/
 * Author: Chandrabhanu Mahapatra <cmahapatra@ti.com>
 */

#include <linux/kernel.h>

#include "omapdss.h"
#include "dispc.h"

static const struct dispc_coef coef3_M8[8] = {
	{ 0,  0, 128,  0, 0 },
	{ 0, -4, 123,  9, 0 },
	{ 0, -4, 108, 24, 0 },
	{ 0, -2,  87, 43, 0 },
	{ 0, 64,  64,  0, 0 },
	{ 0, 43,  87, -2, 0 },
	{ 0, 24, 108, -4, 0 },
	{ 0,  9, 123, -4, 0 },
};

static const struct dispc_coef coef3_M9[8] = {
	{ 0,  6, 116,  6, 0 },
	{ 0,  0, 112, 16, 0 },
	{ 0, -2, 100, 30, 0 },
	{ 0, -2,  83, 47, 0 },
	{ 0, 64,  64,  0, 0 },
	{ 0, 47,  83, -2, 0 },
	{ 0, 30, 100, -2, 0 },
	{ 0, 16, 112,  0, 0 },
};

static const struct dispc_coef coef3_M10[8] = {
	{ 0, 10, 108, 10, 0 },
	{ 0,  3, 104, 21, 0 },
	{ 0,  0,  94, 34, 0 },
	{ 0, -1,  80, 49, 0 },
	{ 0, 64,  64,  0, 0 },
	{ 0, 49,  80, -1, 0 },
	{ 0, 34,  94,  0, 0 },
	{ 0, 21, 104,  3, 0 },
};

static const struct dispc_coef coef3_M11[8] = {
	{ 0, 14, 100, 14, 0 },
	{ 0,  6,  98, 24, 0 },
	{ 0,  2,  90, 36, 0 },
	{ 0,  0,  78, 50, 0 },
	{ 0, 64,  64,  0, 0 },
	{ 0, 50,  78,  0, 0 },
	{ 0, 36,  90,  2, 0 },
	{ 0, 24,  98,  6, 0 },
};

static const struct dispc_coef coef3_M12[8] = {
	{ 0, 16,  96, 16, 0 },
	{ 0,  9,  93, 26, 0 },
	{ 0,  4,  86, 38, 0 },
	{ 0,  1,  76, 51, 0 },
	{ 0, 64,  64,  0, 0 },
	{ 0, 51,  76,  1, 0 },
	{ 0, 38,  86,  4, 0 },
	{ 0, 26,  93,  9, 0 },
};

static const struct dispc_coef coef3_M13[8] = {
	{ 0, 18,  92, 18, 0 },
	{ 0, 10,  90, 28, 0 },
	{ 0,  5,  83, 40, 0 },
	{ 0,  1,  75, 52, 0 },
	{ 0, 64,  64,  0, 0 },
	{ 0, 52,  75,  1, 0 },
	{ 0, 40,  83,  5, 0 },
	{ 0, 28,  90, 10, 0 },
};

static const struct dispc_coef coef3_M14[8] = {
	{ 0, 20, 88, 20, 0 },
	{ 0, 12, 86, 30, 0 },
	{ 0,  6, 81, 41, 0 },
	{ 0,  2, 74, 52, 0 },
	{ 0, 64, 64,  0, 0 },
	{ 0, 52, 74,  2, 0 },
	{ 0, 41, 81,  6, 0 },
	{ 0, 30, 86, 12, 0 },
};

static const struct dispc_coef coef3_M16[8] = {
	{ 0, 22, 84, 22, 0 },
	{ 0, 14, 82, 32, 0 },
	{ 0,  8, 78, 42, 0 },
	{ 0,  3, 72, 53, 0 },
	{ 0, 64, 64,  0, 0 },
	{ 0, 53, 72,  3, 0 },
	{ 0, 42, 78,  8, 0 },
	{ 0, 32, 82, 14, 0 },
};

static const struct dispc_coef coef3_M19[8] = {
	{ 0, 24, 80, 24, 0 },
	{ 0, 16, 79, 33, 0 },
	{ 0,  9, 76, 43, 0 },
	{ 0,  4, 70, 54, 0 },
	{ 0, 64, 64,  0, 0 },
	{ 0, 54, 70,  4, 0 },
	{ 0, 43, 76,  9, 0 },
	{ 0, 33, 79, 16, 0 },
};

static const struct dispc_coef coef3_M22[8] = {
	{ 0, 25, 78, 25, 0 },
	{ 0, 17, 77, 34, 0 },
	{ 0, 10, 74, 44, 0 },
	{ 0,  5, 69, 54, 0 },
	{ 0, 64, 64,  0, 0 },
	{ 0, 54, 69,  5, 0 },
	{ 0, 44, 74, 10, 0 },
	{ 0, 34, 77, 17, 0 },
};

static const struct dispc_coef coef3_M26[8] = {
	{ 0, 26, 76, 26, 0 },
	{ 0, 19, 74, 35, 0 },
	{ 0, 11, 72, 45, 0 },
	{ 0,  5, 69, 54, 0 },
	{ 0, 64, 64,  0, 0 },
	{ 0, 54, 69,  5, 0 },
	{ 0, 45, 72, 11, 0 },
	{ 0, 35, 74, 19, 0 },
};

static const struct dispc_coef coef3_M32[8] = {
	{ 0, 27, 74, 27, 0 },
	{ 0, 19, 73, 36, 0 },
	{ 0, 12, 71, 45, 0 },
	{ 0,  6, 68, 54, 0 },
	{ 0, 64, 64,  0, 0 },
	{ 0, 54, 68,  6, 0 },
	{ 0, 45, 71, 12, 0 },
	{ 0, 36, 73, 19, 0 },
};

static const struct dispc_coef coef5_M8[8] = {
	{   0,   0, 128,   0,   0 },
	{  -2,  14, 125, -10,   1 },
	{  -6,  33, 114, -15,   2 },
	{ -10,  55,  98, -16,   1 },
	{   0, -14,  78,  78, -14 },
	{   1, -16,  98,  55, -10 },
	{   2, -15, 114,  33,  -6 },
	{   1, -10, 125,  14,  -2 },
};

static const struct dispc_coef coef5_M9[8] = {
	{  -3,  10, 114,  10,  -3 },
	{  -6,  24, 111,   0,  -1 },
	{  -8,  40, 103,  -7,   0 },
	{ -11,  58,  91, -11,   1 },
	{   0, -12,  76,  76, -12 },
	{   1, -11,  91,  58, -11 },
	{   0,  -7, 103,  40,  -8 },
	{  -1,   0, 111,  24,  -6 },
};

static const struct dispc_coef coef5_M10[8] = {
	{  -4,  18, 100,  18,  -4 },
	{  -6,  30,  99,   8,  -3 },
	{  -8,  44,  93,   0,  -1 },
	{  -9,  58,  84,  -5,   0 },
	{   0,  -8,  72,  72,  -8 },
	{   0,  -5,  84,  58,  -9 },
	{  -1,   0,  93,  44,  -8 },
	{  -3,   8,  99,  30,  -6 },
};

static const struct dispc_coef coef5_M11[8] = {
	{  -5,  23,  92,  23,  -5 },
	{  -6,  34,  90,  13,  -3 },
	{  -6,  45,  85,   6,  -2 },
	{  -6,  57,  78,   0,  -1 },
	{   0,  -4,  68,  68,  -4 },
	{  -1,   0,  78,  57,  -6 },
	{  -2,   6,  85,  45,  -6 },
	{  -3,  13,  90,  34,  -6 },
};

static const struct dispc_coef coef5_M12[8] = {
	{  -4,  26,  84,  26,  -4 },
	{  -5,  36,  82,  18,  -3 },
	{  -4,  46,  78,  10,  -2 },
	{  -3,  55,  72,   5,  -1 },
	{   0,   0,  64,  64,   0 },
	{  -1,   5,  72,  55,  -3 },
	{  -2,  10,  78,  46,  -4 },
	{  -3,  18,  82,  36,  -5 },
};

static const struct dispc_coef coef5_M13[8] = {
	{  -3,  28,  78,  28,  -3 },
	{  -3,  37,  76,  21,  -3 },
	{  -2,  45,  73,  14,  -2 },
	{   0,  53,  68,   8,  -1 },
	{   0,   3,  61,  61,   3 },
	{  -1,   8,  68,  53,   0 },
	{  -2,  14,  73,  45,  -2 },
	{  -3,  21,  76,  37,  -3 },
};

static const struct dispc_coef coef5_M14[8] = {
	{  -2,  30,  72,  30,  -2 },
	{  -1,  37,  71,  23,  -2 },
	{   0,  45,  69,  16,  -2 },
	{   3,  52,  64,  10,  -1 },
	{   0,   6,  58,  58,   6 },
	{  -1,  10,  64,  52,   3 },
	{  -2,  16,  69,  45,   0 },
	{  -2,  23,  71,  37,  -1 },
};

static const struct dispc_coef coef5_M16[8] = {
	{   0,  31,  66,  31,   0 },
	{   1,  38,  65,  25,  -1 },
	{   3,  44,  62,  20,  -1 },
	{   6,  49,  59,  14,   0 },
	{   0,  10,  54,  54,  10 },
	{   0,  14,  59,  49,   6 },
	{  -1,  20,  62,  44,   3 },
	{  -1,  25,  65,  38,   1 },
};

static const struct dispc_coef coef5_M19[8] = {
	{   3,  32,  58,  32,   3 },
	{   4,  38,  58,  27,   1 },
	{   7,  42,  55,  23,   1 },
	{  10,  46,  54,  18,   0 },
	{   0,  14,  50,  50,  14 },
	{   0,  18,  54,  46,  10 },
	{   1,  23,  55,  42,   7 },
	{   1,  27,  58,  38,   4 },
};

static const struct dispc_coef coef5_M22[8] = {
	{   4,  33,  54,  33,   4 },
	{   6,  37,  54,  28,   3 },
	{   9,  41,  53,  24,   1 },
	{  12,  45,  51,  20,   0 },
	{   0,  16,  48,  48,  16 },
	{   0,  20,  51,  45,  12 },
	{   1,  24,  53,  41,   9 },
	{   3,  28,  54,  37,   6 },
};

static const struct dispc_coef coef5_M26[8] = {
	{   6,  33,  50,  33,   6 },
	{   8,  36,  51,  29,   4 },
	{  11,  40,  50,  25,   2 },
	{  14,  43,  48,  22,   1 },
	{   0,  18,  46,  46,  18 },
	{   1,  22,  48,  43,  14 },
	{   2,  25,  50,  40,  11 },
	{   4,  29,  51,  36,   8 },
};

static const struct dispc_coef coef5_M32[8] = {
	{   7,  33,  48,  33,   7 },
	{  10,  36,  48,  29,   5 },
	{  13,  39,  47,  26,   3 },
	{  16,  42,  46,  23,   1 },
	{   0,  19,  45,  45,  19 },
	{   1,  23,  46,  42,  16 },
	{   3,  26,  47,  39,  13 },
	{   5,  29,  48,  36,  10 },
};

const struct dispc_coef *dispc_ovl_get_scale_coef(int inc, int five_taps)
{
	int i;
	static const struct {
		int Mmin;
		int Mmax;
		const struct dispc_coef *coef_3;
		const struct dispc_coef *coef_5;
	} coefs[] = {
		{ 27, 32, coef3_M32, coef5_M32 },
		{ 23, 26, coef3_M26, coef5_M26 },
		{ 20, 22, coef3_M22, coef5_M22 },
		{ 17, 19, coef3_M19, coef5_M19 },
		{ 15, 16, coef3_M16, coef5_M16 },
		{ 14, 14, coef3_M14, coef5_M14 },
		{ 13, 13, coef3_M13, coef5_M13 },
		{ 12, 12, coef3_M12, coef5_M12 },
		{ 11, 11, coef3_M11, coef5_M11 },
		{ 10, 10, coef3_M10, coef5_M10 },
		{  9,  9,  coef3_M9,  coef5_M9 },
		{  4,  8,  coef3_M8,  coef5_M8 },
		/*
		 * When upscaling more than two times, blockiness and outlines
		 * around the image are observed when M8 tables are used. M11,
		 * M16 and M19 tables are used to prevent this.
		 */
		{  3,  3, coef3_M11, coef5_M11 },
		{  2,  2, coef3_M16, coef5_M16 },
		{  0,  1, coef3_M19, coef5_M19 },
	};

	inc /= 128;
	for (i = 0; i < ARRAY_SIZE(coefs); ++i)
		if (inc >= coefs[i].Mmin && inc <= coefs[i].Mmax)
			return five_taps ? coefs[i].coef_5 : coefs[i].coef_3;
	return NULL;
}