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/io.h>
  20
  21 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  22 MODULE_DESCRIPTION("PC Speaker beeper driver");
  23 MODULE_LICENSE("GPL");
  24
  25 static char pcspkr_name[] = "PC Speaker";
  26 static char pcspkr_phys[] = "isa0061/input0";
  27 static struct input_dev pcspkr_dev;
  28
  29 spinlock_t i8253_beep_lock = SPIN_LOCK_UNLOCKED;
  30
  31 static int pcspkr_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
  32 {
  33         unsigned int count = 0;
  34         unsigned long flags;
  35
  36         if (type != EV_SND)
  37                 return -1;
  38
  39         switch (code) {
  40                 case SND_BELL: if (value) value = 1000;
  41                 case SND_TONE: break;
  42                 default: return -1;
  43         }
  44
  45         if (value > 20 && value < 32767)
  46                 count = CLOCK_TICK_RATE / value;
  47
  48         spin_lock_irqsave(&i8253_beep_lock, flags);
  49
  50         if (count) {
  51                 /* enable counter 2 */
  52                 outb_p(inb_p(0x61) | 3, 0x61);
  53                 /* set command for counter 2, 2 byte write */
  54                 outb_p(0xB6, 0x43);
  55                 /* select desired HZ */
  56                 outb_p(count & 0xff, 0x42);
  57                 outb((count >> 8) & 0xff, 0x42);
  58         } else {
  59                 /* disable counter 2 */
  60                 outb(inb_p(0x61) & 0xFC, 0x61);
  61         }
  62
  63         spin_unlock_irqrestore(&i8253_beep_lock, flags);
  64
  65         return 0;
  66 }
  67
  68 static int __init pcspkr_init(void)
  69 {
  70         pcspkr_dev.evbit[0] = BIT(EV_SND);
  71         pcspkr_dev.sndbit[0] = BIT(SND_BELL) | BIT(SND_TONE);
  72         pcspkr_dev.event = pcspkr_event;
  73
  74         pcspkr_dev.name = pcspkr_name;
  75         pcspkr_dev.phys = pcspkr_phys;
  76         pcspkr_dev.id.bustype = BUS_ISA;
  77         pcspkr_dev.id.vendor = 0x001f;
  78         pcspkr_dev.id.product = 0x0001;
  79         pcspkr_dev.id.version = 0x0100;
  80
  81         input_register_device(&pcspkr_dev);
  82
  83         printk(KERN_INFO "input: %s\n", pcspkr_name);
  84
  85         return 0;
  86 }
  87
  88 static void __exit pcspkr_exit(void)
  89 {
  90         input_unregister_device(&pcspkr_dev);
  91 }
  92
  93 module_init(pcspkr_init);
  94 module_exit(pcspkr_exit);