firmware/drivers/audio/dac3550a.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id: dac.c 17847 2008-06-28 18:10:04Z bagder $
   9  *
  10  * Copyright (C) 2002 by Linus Nielsen Feltzing
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include "config.h"
  22 #include "stdbool.h"
  23 #include "i2c.h"
  24 #include "debug.h"
  25 #include "dac3550a.h"
  26
  27 static bool line_in_enabled = false;
  28 static bool dac_enabled = false;
  29
  30 /* convert tenth of dB volume (-780..+180) to dac3550 register value */
  31 int tenthdb2reg(int db)
  32 {
  33     if (db < -540)                  /* 3 dB steps */
  34         return (db + 780) / 30;
  35     else                            /* 1.5 dB steps */
  36         return (db + 660) / 15;
  37 }
  38
  39 int dac_volume(unsigned int left, unsigned int right, bool deemph)
  40 {
  41     int ret = 0;
  42     unsigned char buf[3];
  43
  44     i2c_begin();
  45
  46     if (left > 0x38)
  47         left = 0x38;
  48     if (right > 0x38)
  49         right = 0x38;
  50
  51     buf[0] = DAC_REG_WRITE | DAC_AVOL;
  52     buf[1] = (left & 0x3f) | (deemph ? 0x40 : 0);
  53     buf[2] = right & 0x3f;
  54
  55     /* send write command */
  56     if (i2c_write(DAC_DEV_WRITE,buf,3))
  57     {
  58         ret = -1;
  59     }
  60
  61     i2c_end();
  62     return ret;
  63 }
  64
  65 /******************************************************************
  66 ** Bit6:  0 = 3V        1 = 5V
  67 ** Bit5:  0 = normal    1 = low power
  68 ** Bit4:  0 = AUX2 off  1 = AUX2 on
  69 ** Bit3:  0 = AUX1 off  1 = AUX1 on
  70 ** Bit2:  0 = DAC off   1 = DAC on
  71 ** Bit1:  0 = stereo    1 = mono
  72 ** Bit0:  0 = normal right amp   1 = inverted right amp
  73 ******************************************************************/
  74 /* dac_config is called once to initialize it. we will apply
  75    our static settings because of the init flow.
  76    dac_init -> dac_line_in -> mpeg_init -> dac_config
  77 */
  78 static int dac_config(void)
  79 {
  80     int ret = 0;
  81     unsigned char buf[2];
  82
  83     i2c_begin();
  84
  85     buf[0] = DAC_REG_WRITE | DAC_GCFG;
  86     buf[1] = (dac_enabled ? 0x04 : 0) |
  87         (line_in_enabled ? 0x08 : 0);
  88
  89     /* send write command */
  90     if (i2c_write(DAC_DEV_WRITE,buf,2))
  91     {
  92         ret = -1;
  93     }
  94
  95     i2c_end();
  96     return ret;
  97 }
  98
  99 void dac_enable(bool enable)
 100 {
 101     dac_enabled = enable;
 102     dac_config();
 103 }
 104
 105 void dac_line_in(bool enable)
 106 {
 107     line_in_enabled = enable;
 108     dac_config();
 109 }
 110
 111 void dac_init(void)
 112 {
 113     unsigned char buf[2];
 114
 115     i2c_begin();
 116
 117     buf[0] = DAC_REG_WRITE | DAC_SR_REG;
 118     buf[1] = 0x07;
 119
 120     /* send write command */
 121     i2c_write(DAC_DEV_WRITE,buf,2);
 122     i2c_end();
 123 }
 124