payloads/libpayload/drivers/speaker.c

   1 /*
   2  *
   3  * Copyright (C) 2007 Uwe Hermann <uwe@hermann-uwe.de>
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 /*
  30  * Datasheet:
  31  *  - Name: 82C54 CHMOS Programmable Interval Timer
  32  *  - PDF: http://www.intel.com/design/archives/periphrl/docs/23124406.pdf
  33  *  - Order number: 231244-006
  34  */
  35
  36 #include <libpayload.h>
  37
  38 #define I82C54_CONTROL_WORD_REGISTER    0x43    /* Write-only. */
  39
  40 #define I82C54_COUNTER0                 0x40
  41 #define I82C54_COUNTER1                 0x41
  42 #define I82C54_COUNTER2                 0x42
  43
  44 #define PC_SPEAKER_PORT                 0x61
  45
  46 /**
  47  * Use the PC speaker to create a tone/sound of the specified frequency.
  48  *
  49  * The Intel 82C54 CHMOS Programmable Interval Timer (PIT) provides a
  50  * superset of the functions of the original Intel 8253/8254 PIT. It has
  51  * three programmable counters/timers (counter 0, 1, and 2). Counter 2 can
  52  * be used to generate tones/sounds of various frequencies and duration.
  53  *
  54  * See also:
  55  *  - http://en.wikipedia.org/wiki/Pc_speaker
  56  *  - http://en.wikipedia.org/wiki/Intel_8253
  57  *
  58  * @param freq The frequency of the tone.
  59  */
  60 void speaker_enable(u16 freq)
  61 {
  62         u16 reg16 = 1193180 / freq;
  63
  64         /* Select counter 2. Read/write LSB first, then MSB. Use mode 3
  65            (square wave generator). Use a 16bit binary counter. */
  66         outb(0xb6, I82C54_CONTROL_WORD_REGISTER);
  67
  68         /* Set the desired tone frequency. */
  69         outb((u8)(reg16 & 0x00ff), I82C54_COUNTER2);    /* LSB. */
  70         outb((u8)(reg16 >> 8), I82C54_COUNTER2);        /* MSB. */
  71
  72         /* Enable the PC speaker (set bits 0 and 1). */
  73         outb(inb(PC_SPEAKER_PORT) | 0x03, PC_SPEAKER_PORT);
  74 }
  75
  76 /**
  77  * Disable the PC speaker.
  78  */
  79 void speaker_disable(void)
  80 {
  81         /* Disable the PC speaker (clear bits 0 and 1). */
  82         outb(inb(PC_SPEAKER_PORT) & 0xfc, PC_SPEAKER_PORT);
  83 }
  84
  85 /**
  86  * Use the PC speaker to create a tone/beep of the specified frequency
  87  * and duration.
  88  *
  89  * Wait for a short amount of time after the beep to make it distinguishable
  90  * from the next beep (if any).
  91  *
  92  * @param freq The frequency of the tone/beep.
  93  * @param duration The duration of the tone/beep in milliseconds.
  94  */
  95 void speaker_tone(u16 freq, unsigned int duration)
  96 {
  97         speaker_enable(freq);
  98         mdelay(duration);
  99         speaker_disable();
 100         mdelay(100);
 101 }