linux_old1/drivers/input/misc/pcspkr.c

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/*
* PC Speaker beeper driver for Linux
*
* Copyright (c) 2002 Vojtech Pavlik
* Copyright (c) 1992 Orest Zborowski
*
*/
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/i8253.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <linux/timex.h>
#include <linux/io.h>
MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("PC Speaker beeper driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pcspkr");
static int pcspkr_event(struct input_dev *dev, unsigned int type,
unsigned int code, int value)
{
unsigned int count = 0;
unsigned long flags;
if (type != EV_SND)
return -EINVAL;
switch (code) {
case SND_BELL:
if (value)
value = 1000;
case SND_TONE:
break;
default:
return -EINVAL;
}
if (value > 20 && value < 32767)
count = PIT_TICK_RATE / value;
raw_spin_lock_irqsave(&i8253_lock, flags);
if (count) {
/* set command for counter 2, 2 byte write */
outb_p(0xB6, 0x43);
/* select desired HZ */
outb_p(count & 0xff, 0x42);
outb((count >> 8) & 0xff, 0x42);
Input: pcspkr - fix PIT lockup on some chipsets There've been reports [1] about the sysem bell causing a hard lockup. My machine was affected as well: any speaker output hung the machine completely, nothing in the logs, no magic sysrq, etc., looked like a hardware problem. Had a closer look on the issue, and it turned out that the pcspkr module is responsible. The cause is the bad setup of Timer 2 in the i8253 controller, which probably hangs the whole PIT controller. Intel datasheets [2] state that the timer registers are in an undefined state after reset and they need to be programmed before enabling the timer. (And enabling without programming the frequency first doesn't make sense anyway). I don't know which chipsets are affected (if not all), it also depends on the BIOS whether it initializes the timer (e.g. to beep when you start the machine). The following patch solved the issue on my ICH6 notebook, couldn't test it with any others, but should be safe to apply. [1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/146151 https://bugs.launchpad.net/ubuntu/+bug/270790 http://ubuntuforums.org/showthread.php?t=227693 http://bugs.gentoo.org/show_bug.cgi?id=222583 https://bugzilla.redhat.com/show_bug.cgi?id=454225 [2] http://www.intel.com/assets/pdf/datasheet/252516.pdf http://www.intel.com/assets/pdf/datasheet/301473.pdf http://www.intel.com/design/chipsets/datashts/29065503.pdf Signed-off-by: Zoltan Devai <zdevai@gmail.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2008-11-13 12:05:40 +08:00
/* enable counter 2 */
outb_p(inb_p(0x61) | 3, 0x61);
} else {
/* disable counter 2 */
outb(inb_p(0x61) & 0xFC, 0x61);
}
raw_spin_unlock_irqrestore(&i8253_lock, flags);
return 0;
}
static int pcspkr_probe(struct platform_device *dev)
{
struct input_dev *pcspkr_dev;
int err;
pcspkr_dev = input_allocate_device();
if (!pcspkr_dev)
return -ENOMEM;
pcspkr_dev->name = "PC Speaker";
pcspkr_dev->phys = "isa0061/input0";
pcspkr_dev->id.bustype = BUS_ISA;
pcspkr_dev->id.vendor = 0x001f;
pcspkr_dev->id.product = 0x0001;
pcspkr_dev->id.version = 0x0100;
pcspkr_dev->dev.parent = &dev->dev;
pcspkr_dev->evbit[0] = BIT_MASK(EV_SND);
pcspkr_dev->sndbit[0] = BIT_MASK(SND_BELL) | BIT_MASK(SND_TONE);
pcspkr_dev->event = pcspkr_event;
err = input_register_device(pcspkr_dev);
if (err) {
input_free_device(pcspkr_dev);
return err;
}
platform_set_drvdata(dev, pcspkr_dev);
return 0;
}
static int pcspkr_remove(struct platform_device *dev)
{
struct input_dev *pcspkr_dev = platform_get_drvdata(dev);
input_unregister_device(pcspkr_dev);
/* turn off the speaker */
pcspkr_event(NULL, EV_SND, SND_BELL, 0);
return 0;
}
static int pcspkr_suspend(struct device *dev)
{
pcspkr_event(NULL, EV_SND, SND_BELL, 0);
return 0;
}
static void pcspkr_shutdown(struct platform_device *dev)
{
/* turn off the speaker */
pcspkr_event(NULL, EV_SND, SND_BELL, 0);
}
static const struct dev_pm_ops pcspkr_pm_ops = {
.suspend = pcspkr_suspend,
};
static struct platform_driver pcspkr_platform_driver = {
.driver = {
.name = "pcspkr",
.pm = &pcspkr_pm_ops,
},
.probe = pcspkr_probe,
.remove = pcspkr_remove,
.shutdown = pcspkr_shutdown,
};
module_platform_driver(pcspkr_platform_driver);