drivers/input/misc/pcspkr.c

   1 /*
   2  *  PC Speaker beeper driver for Linux
   3  *
   4  *  Copyright (c) 2002 Vojtech Pavlik
   5  *  Copyright (c) 1992 Orest Zborowski
   6  *
   7  */
   8
   9 /*
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License version 2 as published by
  12  * the Free Software Foundation
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/input.h>
  19 #include <asm/8253pit.h>
  20 #include <asm/io.h>
  21
  22 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  23 MODULE_DESCRIPTION("PC Speaker beeper driver");
  24 MODULE_LICENSE("GPL");
  25
  26 static char pcspkr_name[] = "PC Speaker";
  27 static char pcspkr_phys[] = "isa0061/input0";
  28 static struct input_dev pcspkr_dev;
  29
  30 static DEFINE_SPINLOCK(i8253_beep_lock);
  31
  32 static int pcspkr_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
  33 {
  34         unsigned int count = 0;
  35         unsigned long flags;
  36
  37         if (type != EV_SND)
  38                 return -1;
  39
  40         switch (code) {
  41                 case SND_BELL: if (value) value = 1000;
  42                 case SND_TONE: break;
  43                 default: return -1;
  44         }
  45
  46         if (value > 20 && value < 32767)
  47                 count = PIT_TICK_RATE / value;
  48
  49         spin_lock_irqsave(&i8253_beep_lock, flags);
  50
  51         if (count) {
  52                 /* enable counter 2 */
  53                 outb_p(inb_p(0x61) | 3, 0x61);
  54                 /* set command for counter 2, 2 byte write */
  55                 outb_p(0xB6, 0x43);
  56                 /* select desired HZ */
  57                 outb_p(count & 0xff, 0x42);
  58                 outb((count >> 8) & 0xff, 0x42);
  59         } else {
  60                 /* disable counter 2 */
  61                 outb(inb_p(0x61) & 0xFC, 0x61);
  62         }
  63
  64         spin_unlock_irqrestore(&i8253_beep_lock, flags);
  65
  66         return 0;
  67 }
  68
  69 static int __init pcspkr_init(void)
  70 {
  71         pcspkr_dev.evbit[0] = BIT(EV_SND);
  72         pcspkr_dev.sndbit[0] = BIT(SND_BELL) | BIT(SND_TONE);
  73         pcspkr_dev.event = pcspkr_event;
  74
  75         pcspkr_dev.name = pcspkr_name;
  76         pcspkr_dev.phys = pcspkr_phys;
  77         pcspkr_dev.id.bustype = BUS_ISA;
  78         pcspkr_dev.id.vendor = 0x001f;
  79         pcspkr_dev.id.product = 0x0001;
  80         pcspkr_dev.id.version = 0x0100;
  81
  82         input_register_device(&pcspkr_dev);
  83
  84         printk(KERN_INFO "input: %s\n", pcspkr_name);
  85
  86         return 0;
  87 }
  88
  89 static void __exit pcspkr_exit(void)
  90 {
  91         input_unregister_device(&pcspkr_dev);
  92         /* turn off the speaker */
  93         pcspkr_event(NULL, EV_SND, SND_BELL, 0);
  94 }
  95
  96 module_init(pcspkr_init);
  97 module_exit(pcspkr_exit);