xref: /openbmc/linux/drivers/input/misc/pcspkr.c (revision 76b7cddf)
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->name = "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);
98