tas-basstreble.h

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/*
 * This file is only included exactly once!
 *
 * The tables here are derived from the tas3004 datasheet,
 * modulo typo corrections and some smoothing...
 */

#define TAS3004_TREBLE_MIN  0
#define TAS3004_TREBLE_MAX  72
#define TAS3004_BASS_MIN    0
#define TAS3004_BASS_MAX    72
#define TAS3004_TREBLE_ZERO 36
#define TAS3004_BASS_ZERO   36

static u8 tas3004_treble_table[] = {
    150, /* -18 dB */
    149,
    148,
    147,
    146,
    145,
    144,
    143,
    142,
    141,
    140,
    139,
    138,
    137,
    136,
    135,
    134,
    133,
    132,
    131,
    130,
    129,
    128,
    127,
    126,
    125,
    124,
    123,
    122,
    121,
    120,
    119,
    118,
    117,
    116,
    115,
    114, /* 0 dB */
    113,
    112,
    111,
    109,
    108,
    107,
    105,
    104,
    103,
    101,
    99,
    98,
    96,
    93,
    91,
    89,
    86,
    83,
    81,
    77,
    74,
    71,
    67,
    63,
    59,
    54,
    49,
    44,
    38,
    32,
    26,
    19,
    10,
    4,
    2,
    1, /* +18 dB */
};

static inline u8 tas3004_treble(int idx)
{
    return tas3004_treble_table[idx];
}

/* I only save the difference here to the treble table
 * so that the binary is smaller...
 * I have also ignored completely differences of
 * +/- 1
 */
static s8 tas3004_bass_diff_to_treble[] = {
    2, /* 7 dB, offset 50 */
    2,
    2,
    2,
    2,
    1,
    2,
    2,
    2,
    3,
    4,
    4,
    5,
    6,
    7,
    8,
    9,
    10,
    11,
    14,
    13,
    8,
    1, /* 18 dB */
};

static inline u8 tas3004_bass(int idx)
{
    u8 result = tas3004_treble_table[idx];

    if (idx >= 50)
        result += tas3004_bass_diff_to_treble[idx-50];
    return result;
}