kernel/drivers/char/sound/speaker.c

   1 /*
   2  *  ZeX/OS
   3  *  Copyright (C) 2007  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   4  *  Copyright (C) 2008  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   5  *
   6  *  This program is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20
  21 #include <config.h>
  22 #include <build.h>
  23
  24 #ifdef ARCH_i386
  25
  26 #include <system.h>
  27 #include <dev.h>
  28 #include <arch/io.h>
  29 #include <speaker.h>
  30
  31 #define PIT_TICK_RATE           1193182UL
  32
  33 static void pcspkr_do_sound (unsigned int freq)
  34 {
  35         unsigned int count = 0;
  36
  37         if (freq)
  38                 count = PIT_TICK_RATE/freq;
  39         else
  40                 count = 0;      // disable sound
  41
  42         if (count) {
  43                 /* enable counter 2 */
  44                 outb_p(inb_p(0x61) | 3, 0x61);
  45                 /* set command for counter 2, 2 byte write */
  46                 outb_p(0xB6, 0x43);
  47                 /* select desired HZ */
  48                 outb_p(count & 0xff, 0x42);
  49                 outb((count >> 8) & 0xff, 0x42);
  50         } else {
  51                 /* disable counter 2 */
  52                 outb(inb_p(0x61) & 0xFC, 0x61);
  53         }
  54 }
  55
  56 bool pcspk_acthandler (unsigned act, unsigned freq)
  57 {
  58         switch (act) {
  59                 case DEV_ACT_INIT:
  60                 case DEV_ACT_STOP:
  61                 {
  62                         pcspkr_do_sound (0);
  63
  64                         return 1;
  65                 }
  66                 break;
  67                 case DEV_ACT_PLAY:
  68                 {
  69                         pcspkr_do_sound (freq);
  70
  71                         return 1;
  72                 }
  73                 break;
  74         }
  75
  76         return 0;
  77 }
  78 #endif