/* * This file is part of the libpayload project. * * Copyright (C) 2007 Uwe Hermann <uwe@hermann-uwe.de> * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * Datasheet: * - Name: 82C54 CHMOS Programmable Interval Timer * - PDF: http://www.intel.com/design/archives/periphrl/docs/23124406.pdf * - Order number: 231244-006 */ #include <libpayload.h> #define I82C54_CONTROL_WORD_REGISTER 0x43 /* Write-only. */ #define I82C54_COUNTER0 0x40 #define I82C54_COUNTER1 0x41 #define I82C54_COUNTER2 0x42 #define PC_SPEAKER_PORT 0x61 /** * Use the PC speaker to create a tone/sound of the specified frequency. * * The Intel 82C54 CHMOS Programmable Interval Timer (PIT) provides a * superset of the functions of the original Intel 8253/8254 PIT. It has * three programmable counters/timers (counter 0, 1, and 2). Counter 2 can * be used to generate tones/sounds of various frequencies and duration. * * See also: * - http://en.wikipedia.org/wiki/Pc_speaker * - http://en.wikipedia.org/wiki/Intel_8253 * * @param freq The frequency of the tone. */ void speaker_enable(u16 freq) { /* Select counter 2. Read/write LSB first, then MSB. Use mode 3 (square wave generator). Use a 16bit binary counter. */ outb(0xb6, I82C54_CONTROL_WORD_REGISTER); /* Set the desired tone frequency. */ outb((u8)(freq & 0x00ff), I82C54_COUNTER2); /* LSB. */ outb((u8)(freq >> 8), I82C54_COUNTER2); /* MSB. */ /* Enable the PC speaker (set bits 0 and 1). */ outb(inb(PC_SPEAKER_PORT) | 0x03, PC_SPEAKER_PORT); } /** * Disable the PC speaker. */ void speaker_disable(void) { /* Disable the PC speaker (clear bits 0 and 1). */ outb(inb(PC_SPEAKER_PORT) & 0xfc, PC_SPEAKER_PORT); } /** * Use the PC speaker to create a tone/beep of the specified frequency * and duration. * * Wait for a short amount of time after the beep to make it distinguishable * from the next beep (if any). * * @param freq The frequency of the tone/beep. * @param duration The duration of the tone/beep in milliseconds. */ void speaker_tone(u16 freq, unsigned int duration) { speaker_enable(freq); mdelay(duration); speaker_disable(); mdelay(100); }