text: /***************************************************************************
   *             __________               __   ___.
   *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   *                     \/            \/     \/    \/            \/
   * $Id$
   *
   * Driver for TSC2100 audio codec
   *
   * Copyright (c) 2008 Jonathan Gordon
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version 2
   * of the License, or (at your option) any later version.
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
   * KIND, either express or implied.
   *
   ****************************************************************************/
  #include "cpu.h"
  #include "debug.h"
  #include "system.h"
  #include "audio.h"
  
  #include "audiohw.h"
  #include "sound.h"
  #include "tsc2100.h"
  
  static bool is_muted = false;
  /* convert tenth of dB volume to volume register value */
  static int vol_tenthdb2hw(int db)
  {
      /* 0 to -63.0dB in 1dB steps, tsc2100 can goto -63.5 in 0.5dB steps */
      if (db <= -640) {
          return 0x7E;
      } else if (db >= 0) {
          return 0x00;
      } else {
          return(-((db)/5));
      }
  }
  
  void audiohw_init(void)
  {
      short val = tsc2100_readreg(TSAC4_PAGE, TSAC4_ADDRESS);
      /* disable DAC PGA soft-stepping */
      val |= TSAC4_DASTDP;
      
      tsc2100_writereg(TSAC4_PAGE, TSAC4_ADDRESS, val);
  }
  
  static void audiohw_mute(bool mute)
  {
      short vol = tsc2100_readreg(TSDACGAIN_PAGE, TSDACGAIN_ADDRESS);
      /* left  mute bit == 1<<15
         right mute bit == 1<<7
       */
      if (mute) 
      {
          vol |= (1<<15)|(1<<7);
      } else 
      {
          vol &= ~((1<<15)|(1<<7));
      }
      is_muted = mute;
      tsc2100_writereg(TSDACGAIN_PAGE, TSDACGAIN_ADDRESS, vol);
  }
  
  void audiohw_postinit(void)
  {
      audiohw_mute(false);
  }
  
  void audiohw_set_volume(int vol_l, int vol_r)
  {
      vol_l = vol_tenthdb2hw(vol_l);
      vol_r = vol_tenthdb2hw(vol_r);
      tsc2100_writereg(TSDACGAIN_PAGE, TSDACGAIN_ADDRESS,
                       (short)((vol_l<<8) | vol_r) );
  }
  
  void audiohw_close(void)
  {
      /* mute headphones */
      audiohw_mute(true);
  }
  
  void audiohw_set_frequency(int fsel)
  {
      int reg_val;
      reg_val = tsc2100_readreg(CONTROL_PAGE2, TSAC1_ADDRESS);
      
      reg_val &= ~(0x07<<3);
      
      switch(fsel) 
      {
      case HW_FREQ_8:
          reg_val |= (0x06<<3);
          break;
      case HW_FREQ_11:
          reg_val |= (0x04<<3);
          break;
      case HW_FREQ_22:
          reg_val |= (0x02<<3);
          break;
      case HW_FREQ_44:
      default:
          break;
      }
  
      tsc2100_writereg(CONTROL_PAGE2, TSAC1_ADDRESS, reg_val);
  }
  