mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-06 02:24:14 +08:00
b6dfb2477f
All watchdog drivers implement the same set of ioctl commands, and fortunately all of them are compatible between 32-bit and 64-bit architectures. Modern drivers always go through drivers/watchdog/wdt.c as an abstraction layer, but older ones implement their own file_operations on a character device for this. Move the handling from fs/compat_ioctl.c into the individual drivers. Note that most of the legacy drivers will never be used on 64-bit hardware, because they are for an old 32-bit SoC implementation, but doing them all at once is safer than trying to guess which ones do or do not need the compat_ioctl handling. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
616 lines
15 KiB
C
616 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* SMsC 37B787 Watchdog Timer driver for Linux 2.6.x.x
|
|
*
|
|
* Based on acquirewdt.c by Alan Cox <alan@lxorguk.ukuu.org.uk>
|
|
* and some other existing drivers
|
|
*
|
|
* The authors do NOT admit liability nor provide warranty for
|
|
* any of this software. This material is provided "AS-IS" in
|
|
* the hope that it may be useful for others.
|
|
*
|
|
* (C) Copyright 2003-2006 Sven Anders <anders@anduras.de>
|
|
*
|
|
* History:
|
|
* 2003 - Created version 1.0 for Linux 2.4.x.
|
|
* 2006 - Ported to Linux 2.6, added nowayout and MAGICCLOSE
|
|
* features. Released version 1.1
|
|
*
|
|
* Theory of operation:
|
|
*
|
|
* A Watchdog Timer (WDT) is a hardware circuit that can
|
|
* reset the computer system in case of a software fault.
|
|
* You probably knew that already.
|
|
*
|
|
* Usually a userspace daemon will notify the kernel WDT driver
|
|
* via the /dev/watchdog special device file that userspace is
|
|
* still alive, at regular intervals. When such a notification
|
|
* occurs, the driver will usually tell the hardware watchdog
|
|
* that everything is in order, and that the watchdog should wait
|
|
* for yet another little while to reset the system.
|
|
* If userspace fails (RAM error, kernel bug, whatever), the
|
|
* notifications cease to occur, and the hardware watchdog will
|
|
* reset the system (causing a reboot) after the timeout occurs.
|
|
*
|
|
* Create device with:
|
|
* mknod /dev/watchdog c 10 130
|
|
*
|
|
* For an example userspace keep-alive daemon, see:
|
|
* Documentation/watchdog/wdt.rst
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/types.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/init.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/io.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
|
|
/* enable support for minutes as units? */
|
|
/* (does not always work correctly, so disabled by default!) */
|
|
#define SMSC_SUPPORT_MINUTES
|
|
#undef SMSC_SUPPORT_MINUTES
|
|
|
|
#define MAX_TIMEOUT 255
|
|
|
|
#define UNIT_SECOND 0
|
|
#define UNIT_MINUTE 1
|
|
|
|
#define VERSION "1.1"
|
|
|
|
#define IOPORT 0x3F0
|
|
#define IOPORT_SIZE 2
|
|
#define IODEV_NO 8
|
|
|
|
static int unit = UNIT_SECOND; /* timer's unit */
|
|
static int timeout = 60; /* timeout value: default is 60 "units" */
|
|
static unsigned long timer_enabled; /* is the timer enabled? */
|
|
|
|
static char expect_close; /* is the close expected? */
|
|
|
|
static DEFINE_SPINLOCK(io_lock);/* to guard the watchdog from io races */
|
|
|
|
static bool nowayout = WATCHDOG_NOWAYOUT;
|
|
|
|
/* -- Low level function ----------------------------------------*/
|
|
|
|
/* unlock the IO chip */
|
|
|
|
static inline void open_io_config(void)
|
|
{
|
|
outb(0x55, IOPORT);
|
|
mdelay(1);
|
|
outb(0x55, IOPORT);
|
|
}
|
|
|
|
/* lock the IO chip */
|
|
static inline void close_io_config(void)
|
|
{
|
|
outb(0xAA, IOPORT);
|
|
}
|
|
|
|
/* select the IO device */
|
|
static inline void select_io_device(unsigned char devno)
|
|
{
|
|
outb(0x07, IOPORT);
|
|
outb(devno, IOPORT+1);
|
|
}
|
|
|
|
/* write to the control register */
|
|
static inline void write_io_cr(unsigned char reg, unsigned char data)
|
|
{
|
|
outb(reg, IOPORT);
|
|
outb(data, IOPORT+1);
|
|
}
|
|
|
|
/* read from the control register */
|
|
static inline char read_io_cr(unsigned char reg)
|
|
{
|
|
outb(reg, IOPORT);
|
|
return inb(IOPORT+1);
|
|
}
|
|
|
|
/* -- Medium level functions ------------------------------------*/
|
|
|
|
static inline void gpio_bit12(unsigned char reg)
|
|
{
|
|
/* -- General Purpose I/O Bit 1.2 --
|
|
* Bit 0, In/Out: 0 = Output, 1 = Input
|
|
* Bit 1, Polarity: 0 = No Invert, 1 = Invert
|
|
* Bit 2, Group Enable Intr.: 0 = Disable, 1 = Enable
|
|
* Bit 3/4, Function select: 00 = GPI/O, 01 = WDT, 10 = P17,
|
|
* 11 = Either Edge Triggered Intr. 2
|
|
* Bit 5/6 (Reserved)
|
|
* Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
|
|
*/
|
|
write_io_cr(0xE2, reg);
|
|
}
|
|
|
|
static inline void gpio_bit13(unsigned char reg)
|
|
{
|
|
/* -- General Purpose I/O Bit 1.3 --
|
|
* Bit 0, In/Out: 0 = Output, 1 = Input
|
|
* Bit 1, Polarity: 0 = No Invert, 1 = Invert
|
|
* Bit 2, Group Enable Intr.: 0 = Disable, 1 = Enable
|
|
* Bit 3, Function select: 0 = GPI/O, 1 = LED
|
|
* Bit 4-6 (Reserved)
|
|
* Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
|
|
*/
|
|
write_io_cr(0xE3, reg);
|
|
}
|
|
|
|
static inline void wdt_timer_units(unsigned char new_units)
|
|
{
|
|
/* -- Watchdog timer units --
|
|
* Bit 0-6 (Reserved)
|
|
* Bit 7, WDT Time-out Value Units Select
|
|
* (0 = Minutes, 1 = Seconds)
|
|
*/
|
|
write_io_cr(0xF1, new_units);
|
|
}
|
|
|
|
static inline void wdt_timeout_value(unsigned char new_timeout)
|
|
{
|
|
/* -- Watchdog Timer Time-out Value --
|
|
* Bit 0-7 Binary coded units (0=Disabled, 1..255)
|
|
*/
|
|
write_io_cr(0xF2, new_timeout);
|
|
}
|
|
|
|
static inline void wdt_timer_conf(unsigned char conf)
|
|
{
|
|
/* -- Watchdog timer configuration --
|
|
* Bit 0 Joystick enable: 0* = No Reset, 1 = Reset WDT upon
|
|
* Gameport I/O
|
|
* Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
|
|
* Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr
|
|
* Bit 3 Reset the timer
|
|
* (Wrong in SMsC documentation? Given as: PowerLED Timout
|
|
* Enabled)
|
|
* Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
|
|
* 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
|
|
*/
|
|
write_io_cr(0xF3, conf);
|
|
}
|
|
|
|
static inline void wdt_timer_ctrl(unsigned char reg)
|
|
{
|
|
/* -- Watchdog timer control --
|
|
* Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occurred
|
|
* Bit 1 Power LED Toggle: 0 = Disable Toggle, 1 = Toggle at 1 Hz
|
|
* Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning)
|
|
* Bit 3 P20 Force Timeout enabled:
|
|
* 0 = P20 activity does not generate the WD timeout event
|
|
* 1 = P20 Allows rising edge of P20, from the keyboard
|
|
* controller, to force the WD timeout event.
|
|
* Bit 4 (Reserved)
|
|
* -- Soft power management --
|
|
* Bit 5 Stop Counter: 1 = Stop software power down counter
|
|
* set via register 0xB8, (self-cleaning)
|
|
* (Upon read: 0 = Counter running, 1 = Counter stopped)
|
|
* Bit 6 Restart Counter: 1 = Restart software power down counter
|
|
* set via register 0xB8, (self-cleaning)
|
|
* Bit 7 SPOFF: 1 = Force software power down (self-cleaning)
|
|
*/
|
|
write_io_cr(0xF4, reg);
|
|
}
|
|
|
|
/* -- Higher level functions ------------------------------------*/
|
|
|
|
/* initialize watchdog */
|
|
|
|
static void wb_smsc_wdt_initialize(void)
|
|
{
|
|
unsigned char old;
|
|
|
|
spin_lock(&io_lock);
|
|
open_io_config();
|
|
select_io_device(IODEV_NO);
|
|
|
|
/* enable the watchdog */
|
|
gpio_bit13(0x08); /* Select pin 80 = LED not GPIO */
|
|
gpio_bit12(0x0A); /* Set pin 79 = WDT not
|
|
GPIO/Output/Polarity=Invert */
|
|
/* disable the timeout */
|
|
wdt_timeout_value(0);
|
|
|
|
/* reset control register */
|
|
wdt_timer_ctrl(0x00);
|
|
|
|
/* reset configuration register */
|
|
wdt_timer_conf(0x00);
|
|
|
|
/* read old (timer units) register */
|
|
old = read_io_cr(0xF1) & 0x7F;
|
|
if (unit == UNIT_SECOND)
|
|
old |= 0x80; /* set to seconds */
|
|
|
|
/* set the watchdog timer units */
|
|
wdt_timer_units(old);
|
|
|
|
close_io_config();
|
|
spin_unlock(&io_lock);
|
|
}
|
|
|
|
/* shutdown the watchdog */
|
|
|
|
static void wb_smsc_wdt_shutdown(void)
|
|
{
|
|
spin_lock(&io_lock);
|
|
open_io_config();
|
|
select_io_device(IODEV_NO);
|
|
|
|
/* disable the watchdog */
|
|
gpio_bit13(0x09);
|
|
gpio_bit12(0x09);
|
|
|
|
/* reset watchdog config register */
|
|
wdt_timer_conf(0x00);
|
|
|
|
/* reset watchdog control register */
|
|
wdt_timer_ctrl(0x00);
|
|
|
|
/* disable timeout */
|
|
wdt_timeout_value(0x00);
|
|
|
|
close_io_config();
|
|
spin_unlock(&io_lock);
|
|
}
|
|
|
|
/* set timeout => enable watchdog */
|
|
|
|
static void wb_smsc_wdt_set_timeout(unsigned char new_timeout)
|
|
{
|
|
spin_lock(&io_lock);
|
|
open_io_config();
|
|
select_io_device(IODEV_NO);
|
|
|
|
/* set Power LED to blink, if we enable the timeout */
|
|
wdt_timer_ctrl((new_timeout == 0) ? 0x00 : 0x02);
|
|
|
|
/* set timeout value */
|
|
wdt_timeout_value(new_timeout);
|
|
|
|
close_io_config();
|
|
spin_unlock(&io_lock);
|
|
}
|
|
|
|
/* get timeout */
|
|
|
|
static unsigned char wb_smsc_wdt_get_timeout(void)
|
|
{
|
|
unsigned char set_timeout;
|
|
|
|
spin_lock(&io_lock);
|
|
open_io_config();
|
|
select_io_device(IODEV_NO);
|
|
set_timeout = read_io_cr(0xF2);
|
|
close_io_config();
|
|
spin_unlock(&io_lock);
|
|
|
|
return set_timeout;
|
|
}
|
|
|
|
/* disable watchdog */
|
|
|
|
static void wb_smsc_wdt_disable(void)
|
|
{
|
|
/* set the timeout to 0 to disable the watchdog */
|
|
wb_smsc_wdt_set_timeout(0);
|
|
}
|
|
|
|
/* enable watchdog by setting the current timeout */
|
|
|
|
static void wb_smsc_wdt_enable(void)
|
|
{
|
|
/* set the current timeout... */
|
|
wb_smsc_wdt_set_timeout(timeout);
|
|
}
|
|
|
|
/* reset the timer */
|
|
|
|
static void wb_smsc_wdt_reset_timer(void)
|
|
{
|
|
spin_lock(&io_lock);
|
|
open_io_config();
|
|
select_io_device(IODEV_NO);
|
|
|
|
/* reset the timer */
|
|
wdt_timeout_value(timeout);
|
|
wdt_timer_conf(0x08);
|
|
|
|
close_io_config();
|
|
spin_unlock(&io_lock);
|
|
}
|
|
|
|
/* return, if the watchdog is enabled (timeout is set...) */
|
|
|
|
static int wb_smsc_wdt_status(void)
|
|
{
|
|
return (wb_smsc_wdt_get_timeout() == 0) ? 0 : WDIOF_KEEPALIVEPING;
|
|
}
|
|
|
|
|
|
/* -- File operations -------------------------------------------*/
|
|
|
|
/* open => enable watchdog and set initial timeout */
|
|
|
|
static int wb_smsc_wdt_open(struct inode *inode, struct file *file)
|
|
{
|
|
/* /dev/watchdog can only be opened once */
|
|
|
|
if (test_and_set_bit(0, &timer_enabled))
|
|
return -EBUSY;
|
|
|
|
if (nowayout)
|
|
__module_get(THIS_MODULE);
|
|
|
|
/* Reload and activate timer */
|
|
wb_smsc_wdt_enable();
|
|
|
|
pr_info("Watchdog enabled. Timeout set to %d %s\n",
|
|
timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)");
|
|
|
|
return stream_open(inode, file);
|
|
}
|
|
|
|
/* close => shut off the timer */
|
|
|
|
static int wb_smsc_wdt_release(struct inode *inode, struct file *file)
|
|
{
|
|
/* Shut off the timer. */
|
|
|
|
if (expect_close == 42) {
|
|
wb_smsc_wdt_disable();
|
|
pr_info("Watchdog disabled, sleeping again...\n");
|
|
} else {
|
|
pr_crit("Unexpected close, not stopping watchdog!\n");
|
|
wb_smsc_wdt_reset_timer();
|
|
}
|
|
|
|
clear_bit(0, &timer_enabled);
|
|
expect_close = 0;
|
|
return 0;
|
|
}
|
|
|
|
/* write => update the timer to keep the machine alive */
|
|
|
|
static ssize_t wb_smsc_wdt_write(struct file *file, const char __user *data,
|
|
size_t len, loff_t *ppos)
|
|
{
|
|
/* See if we got the magic character 'V' and reload the timer */
|
|
if (len) {
|
|
if (!nowayout) {
|
|
size_t i;
|
|
|
|
/* reset expect flag */
|
|
expect_close = 0;
|
|
|
|
/* scan to see whether or not we got the
|
|
magic character */
|
|
for (i = 0; i != len; i++) {
|
|
char c;
|
|
if (get_user(c, data + i))
|
|
return -EFAULT;
|
|
if (c == 'V')
|
|
expect_close = 42;
|
|
}
|
|
}
|
|
|
|
/* someone wrote to us, we should reload the timer */
|
|
wb_smsc_wdt_reset_timer();
|
|
}
|
|
return len;
|
|
}
|
|
|
|
/* ioctl => control interface */
|
|
|
|
static long wb_smsc_wdt_ioctl(struct file *file,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
int new_timeout;
|
|
|
|
union {
|
|
struct watchdog_info __user *ident;
|
|
int __user *i;
|
|
} uarg;
|
|
|
|
static const struct watchdog_info ident = {
|
|
.options = WDIOF_KEEPALIVEPING |
|
|
WDIOF_SETTIMEOUT |
|
|
WDIOF_MAGICCLOSE,
|
|
.firmware_version = 0,
|
|
.identity = "SMsC 37B787 Watchdog",
|
|
};
|
|
|
|
uarg.i = (int __user *)arg;
|
|
|
|
switch (cmd) {
|
|
case WDIOC_GETSUPPORT:
|
|
return copy_to_user(uarg.ident, &ident, sizeof(ident))
|
|
? -EFAULT : 0;
|
|
case WDIOC_GETSTATUS:
|
|
return put_user(wb_smsc_wdt_status(), uarg.i);
|
|
case WDIOC_GETBOOTSTATUS:
|
|
return put_user(0, uarg.i);
|
|
case WDIOC_SETOPTIONS:
|
|
{
|
|
int options, retval = -EINVAL;
|
|
|
|
if (get_user(options, uarg.i))
|
|
return -EFAULT;
|
|
|
|
if (options & WDIOS_DISABLECARD) {
|
|
wb_smsc_wdt_disable();
|
|
retval = 0;
|
|
}
|
|
if (options & WDIOS_ENABLECARD) {
|
|
wb_smsc_wdt_enable();
|
|
retval = 0;
|
|
}
|
|
return retval;
|
|
}
|
|
case WDIOC_KEEPALIVE:
|
|
wb_smsc_wdt_reset_timer();
|
|
return 0;
|
|
case WDIOC_SETTIMEOUT:
|
|
if (get_user(new_timeout, uarg.i))
|
|
return -EFAULT;
|
|
/* the API states this is given in secs */
|
|
if (unit == UNIT_MINUTE)
|
|
new_timeout /= 60;
|
|
if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
|
|
return -EINVAL;
|
|
timeout = new_timeout;
|
|
wb_smsc_wdt_set_timeout(timeout);
|
|
/* fall through - and return the new timeout... */
|
|
case WDIOC_GETTIMEOUT:
|
|
new_timeout = timeout;
|
|
if (unit == UNIT_MINUTE)
|
|
new_timeout *= 60;
|
|
return put_user(new_timeout, uarg.i);
|
|
default:
|
|
return -ENOTTY;
|
|
}
|
|
}
|
|
|
|
/* -- Notifier funtions -----------------------------------------*/
|
|
|
|
static int wb_smsc_wdt_notify_sys(struct notifier_block *this,
|
|
unsigned long code, void *unused)
|
|
{
|
|
if (code == SYS_DOWN || code == SYS_HALT) {
|
|
/* set timeout to 0, to avoid possible race-condition */
|
|
timeout = 0;
|
|
wb_smsc_wdt_disable();
|
|
}
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
/* -- Module's structures ---------------------------------------*/
|
|
|
|
static const struct file_operations wb_smsc_wdt_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.write = wb_smsc_wdt_write,
|
|
.unlocked_ioctl = wb_smsc_wdt_ioctl,
|
|
.compat_ioctl = compat_ptr_ioctl,
|
|
.open = wb_smsc_wdt_open,
|
|
.release = wb_smsc_wdt_release,
|
|
};
|
|
|
|
static struct notifier_block wb_smsc_wdt_notifier = {
|
|
.notifier_call = wb_smsc_wdt_notify_sys,
|
|
};
|
|
|
|
static struct miscdevice wb_smsc_wdt_miscdev = {
|
|
.minor = WATCHDOG_MINOR,
|
|
.name = "watchdog",
|
|
.fops = &wb_smsc_wdt_fops,
|
|
};
|
|
|
|
/* -- Module init functions -------------------------------------*/
|
|
|
|
/* module's "constructor" */
|
|
|
|
static int __init wb_smsc_wdt_init(void)
|
|
{
|
|
int ret;
|
|
|
|
pr_info("SMsC 37B787 watchdog component driver "
|
|
VERSION " initialising...\n");
|
|
|
|
if (!request_region(IOPORT, IOPORT_SIZE, "SMsC 37B787 watchdog")) {
|
|
pr_err("Unable to register IO port %#x\n", IOPORT);
|
|
ret = -EBUSY;
|
|
goto out_pnp;
|
|
}
|
|
|
|
/* set new maximum, if it's too big */
|
|
if (timeout > MAX_TIMEOUT)
|
|
timeout = MAX_TIMEOUT;
|
|
|
|
/* init the watchdog timer */
|
|
wb_smsc_wdt_initialize();
|
|
|
|
ret = register_reboot_notifier(&wb_smsc_wdt_notifier);
|
|
if (ret) {
|
|
pr_err("Unable to register reboot notifier err = %d\n", ret);
|
|
goto out_io;
|
|
}
|
|
|
|
ret = misc_register(&wb_smsc_wdt_miscdev);
|
|
if (ret) {
|
|
pr_err("Unable to register miscdev on minor %d\n",
|
|
WATCHDOG_MINOR);
|
|
goto out_rbt;
|
|
}
|
|
|
|
/* output info */
|
|
pr_info("Timeout set to %d %s\n",
|
|
timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)");
|
|
pr_info("Watchdog initialized and sleeping (nowayout=%d)...\n",
|
|
nowayout);
|
|
out_clean:
|
|
return ret;
|
|
|
|
out_rbt:
|
|
unregister_reboot_notifier(&wb_smsc_wdt_notifier);
|
|
|
|
out_io:
|
|
release_region(IOPORT, IOPORT_SIZE);
|
|
|
|
out_pnp:
|
|
goto out_clean;
|
|
}
|
|
|
|
/* module's "destructor" */
|
|
|
|
static void __exit wb_smsc_wdt_exit(void)
|
|
{
|
|
/* Stop the timer before we leave */
|
|
if (!nowayout) {
|
|
wb_smsc_wdt_shutdown();
|
|
pr_info("Watchdog disabled\n");
|
|
}
|
|
|
|
misc_deregister(&wb_smsc_wdt_miscdev);
|
|
unregister_reboot_notifier(&wb_smsc_wdt_notifier);
|
|
release_region(IOPORT, IOPORT_SIZE);
|
|
|
|
pr_info("SMsC 37B787 watchdog component driver removed\n");
|
|
}
|
|
|
|
module_init(wb_smsc_wdt_init);
|
|
module_exit(wb_smsc_wdt_exit);
|
|
|
|
MODULE_AUTHOR("Sven Anders <anders@anduras.de>");
|
|
MODULE_DESCRIPTION("Driver for SMsC 37B787 watchdog component (Version "
|
|
VERSION ")");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
#ifdef SMSC_SUPPORT_MINUTES
|
|
module_param(unit, int, 0);
|
|
MODULE_PARM_DESC(unit,
|
|
"set unit to use, 0=seconds or 1=minutes, default is 0");
|
|
#endif
|
|
|
|
module_param(timeout, int, 0);
|
|
MODULE_PARM_DESC(timeout, "range is 1-255 units, default is 60");
|
|
|
|
module_param(nowayout, bool, 0);
|
|
MODULE_PARM_DESC(nowayout,
|
|
"Watchdog cannot be stopped once started (default="
|
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|