xref: /openbmc/linux/drivers/input/misc/pcspkr.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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);
98