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 struct input_dev *pcspkr_dev;
  27
  28 static DEFINE_SPINLOCK(i8253_beep_lock);
  29
  30 static int pcspkr_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
  31 {
  32         unsigned int count = 0;
  33         unsigned long flags;
  34
  35         if (type != EV_SND)
  36                 return -1;
  37
  38         switch (code) {
  39                 case SND_BELL: if (value) value = 1000;
  40                 case SND_TONE: break;
  41                 default: return -1;
  42         }
  43
  44         if (value > 20 && value < 32767)
  45                 count = PIT_TICK_RATE / value;
  46
  47         spin_lock_irqsave(&i8253_beep_lock, flags);
  48
  49         if (count) {
  50                 /* enable counter 2 */
  51                 outb_p(inb_p(0x61) | 3, 0x61);
  52                 /* set command for counter 2, 2 byte write */
  53                 outb_p(0xB6, 0x43);
  54                 /* select desired HZ */
  55                 outb_p(count & 0xff, 0x42);
  56                 outb((count >> 8) & 0xff, 0x42);
  57         } else {
  58                 /* disable counter 2 */
  59                 outb(inb_p(0x61) & 0xFC, 0x61);
  60         }
  61
  62         spin_unlock_irqrestore(&i8253_beep_lock, flags);
  63
  64         return 0;
  65 }
  66
  67 static int __init pcspkr_init(void)
  68 {
  69         pcspkr_dev = input_allocate_device();
  70         if (!pcspkr_dev)
  71                 return -ENOMEM;
  72
  73         pcspkr_dev->name = "PC Speaker";
  74         pcspkr_dev->phys = "isa0061/input0";
  75         pcspkr_dev->id.bustype = BUS_ISA;
  76         pcspkr_dev->id.vendor = 0x001f;
  77         pcspkr_dev->id.product = 0x0001;
  78         pcspkr_dev->id.version = 0x0100;
  79
  80         pcspkr_dev->evbit[0] = BIT(EV_SND);
  81         pcspkr_dev->sndbit[0] = BIT(SND_BELL) | BIT(SND_TONE);
  82         pcspkr_dev->event = pcspkr_event;
  83
  84         input_register_device(pcspkr_dev);
  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);