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Diffstat (limited to 'payloads/libpayload/drivers/speaker.c')
| -rw-r--r-- | payloads/libpayload/drivers/speaker.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/payloads/libpayload/drivers/speaker.c b/payloads/libpayload/drivers/speaker.c new file mode 100644 index 0000000000..3b3a750318 --- /dev/null +++ b/payloads/libpayload/drivers/speaker.c @@ -0,0 +1,100 @@ +/* + * 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); +} |