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openwrt-xburst/target/linux/ubicom32/files/drivers/watchdog/ubi32_wdt.c
kaloz 1a29ef8e97 [ubicom32]: move new files out from platform support patch
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@19815 3c298f89-4303-0410-b956-a3cf2f4a3e73
2010-02-22 13:54:47 +00:00

631 lines
15 KiB
C

/*
* drivers/watchdog/ubi32_wdt.c
* Ubicom32 Watchdog Driver
*
* Originally based on softdog.c
* Copyright 2006-2007 Analog Devices Inc.
* Copyright 2006-2007 Michele d'Amico
* Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>
* (C) Copyright 2009, Ubicom, Inc.
*
* This file is part of the Ubicom32 Linux Kernel Port.
*
* The Ubicom32 Linux Kernel Port is free software: you can redistribute
* it and/or modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, either version 2 of the
* License, or (at your option) any later version.
*
* The Ubicom32 Linux Kernel Port is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with the Ubicom32 Linux Kernel Port. If not,
* see <http://www.gnu.org/licenses/>.
*
* Ubicom32 implementation derived from (with many thanks):
* arch/m68knommu
* arch/blackfin
* arch/parisc
*/
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/uaccess.h>
#include <asm/ip5000.h>
#define WATCHDOG_NAME "ubi32-wdt"
#define PFX WATCHDOG_NAME ": "
#define OSC1_FREQ 12000000
#define WATCHDOG_SEC_TO_CYC(x) (OSC1_FREQ * (x))
#define WATCHDOG_MAX_SEC (0xffffffff / OSC1_FREQ)
#define MIN_PROCESSOR_ADDRESS 0x03000000
static DEFINE_SPINLOCK(ubi32_wdt_spinlock);
#define WATCHDOG_TIMEOUT 20
#if defined(CONFIG_WATCHDOG_NOWAYOUT)
#define WATCHDOG_NOWAYOUT 1
#else
#define WATCHDOG_NOWAYOUT 0
#endif
static unsigned int timeout = WATCHDOG_TIMEOUT;
static int nowayout = WATCHDOG_NOWAYOUT;
static struct watchdog_info ubi32_wdt_info;
static unsigned long open_check;
static char expect_close;
#if !defined(CONFIG_SMP)
#define UBI32_WDT_LOCK(lock, flags) local_irq_save(flags)
#define UBI32_WDT_UNLOCK(lock, flags) local_irq_restore(flags)
#define UBI32_WDT_LOCK_CHECK()
#else
#define UBI32_WDT_LOCK(lock, flags) spin_lock_irqsave((lock), (flags));
#define UBI32_WDT_UNLOCK(lock, flags) spin_unlock_irqrestore((lock), (flags));
#define UBI32_WDT_LOCK_CHECK() BUG_ON(!spin_is_locked(&ubi32_wdt_spinlock));
#endif
/*
* ubi32_wdt_remaining()
* Return the approximate number of seconds remaining
*/
static int ubi32_wdt_remaining(void)
{
int compare;
int curr;
UBI32_WDT_LOCK_CHECK();
ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, TIMER_TKEYVAL);
compare = ubicom32_read_reg(&UBICOM32_IO_TIMER->wdcom);
curr = ubicom32_read_reg(&UBICOM32_IO_TIMER->mptval);
ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, 0);
return (compare - curr) / OSC1_FREQ;
}
/*
* ubi32_wdt_keepalive()
* Keep the Userspace Watchdog Alive
*
* The Userspace watchdog got a KeepAlive: schedule the next timeout.
*/
static int ubi32_wdt_keepalive(void)
{
UBI32_WDT_LOCK_CHECK();
ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, TIMER_TKEYVAL);
ubicom32_write_reg(&UBICOM32_IO_TIMER->wdcom,
ubicom32_read_reg(&UBICOM32_IO_TIMER->mptval)
+ WATCHDOG_SEC_TO_CYC(timeout));
ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, 0);
return 0;
}
/*
* ubi32_wdt_stop()
* Stop the on-chip Watchdog
*/
static int ubi32_wdt_stop(void)
{
UBI32_WDT_LOCK_CHECK();
ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, TIMER_TKEYVAL);
ubicom32_write_reg(&UBICOM32_IO_TIMER->wdcfg, TIMER_WATCHDOG_DISABLE);
ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, 0);
return 0;
}
/*
* ubi32_wdt_start()
* Start the on-chip Watchdog
*/
static int ubi32_wdt_start(void)
{
UBI32_WDT_LOCK_CHECK();
ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, TIMER_TKEYVAL);
ubicom32_write_reg(&UBICOM32_IO_TIMER->wdcom,
ubicom32_read_reg(&UBICOM32_IO_TIMER->mptval)
+ WATCHDOG_SEC_TO_CYC(timeout));
ubicom32_write_reg(&UBICOM32_IO_TIMER->wdcfg, ~TIMER_WATCHDOG_DISABLE);
ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, 0);
return 0;
}
/*
* ubi32_wdt_running()
* Return true if the watchdog is configured
*/
static int ubi32_wdt_running(void)
{
int enabled;
UBI32_WDT_LOCK_CHECK();
ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, TIMER_TKEYVAL);
enabled = ubicom32_read_reg(&UBICOM32_IO_TIMER->wdcfg) == ~TIMER_WATCHDOG_DISABLE;
ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, 0);
return enabled;
}
/*
* ubi32_wdt_set_timeout()
* Set the Userspace Watchdog timeout
*
* - @t: new timeout value (in seconds)
*/
static int ubi32_wdt_set_timeout(unsigned long t)
{
UBI32_WDT_LOCK_CHECK();
if (t > WATCHDOG_MAX_SEC) {
printk(KERN_WARNING PFX "request to large: %ld [1-%d] sec)\n", t, WATCHDOG_MAX_SEC);
return -EINVAL;
}
/*
* If we are running, then reset the time value so
* that the new value has an immediate effect.
*/
timeout = t;
if (ubi32_wdt_running()) {
ubi32_wdt_keepalive();
}
return 0;
}
/*
* ubi32_wdt_open()
* Open the Device
*/
static int ubi32_wdt_open(struct inode *inode, struct file *file)
{
unsigned long flags;
if (test_and_set_bit(0, &open_check))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
ubi32_wdt_start();
spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
return nonseekable_open(inode, file);
}
/*
* ubi32_wdt_close()
* Close the Device
*/
static int ubi32_wdt_release(struct inode *inode, struct file *file)
{
unsigned long flags;
/*
* If we don't expect a close, then the watchdog continues
* even though the device is closed. The caller will have
* a full timeout value to reopen the device and continue
* stroking it.
*/
if (expect_close != 42) {
printk(KERN_CRIT PFX
"Unexpected close, not stopping watchdog!\n");
spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
ubi32_wdt_keepalive();
spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
} else {
spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
ubi32_wdt_stop();
spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
}
expect_close = 0;
clear_bit(0, &open_check);
return 0;
}
/*
* ubi32_wdt_write()
* Write to Device
*
* If the user writes nothing, nothing happens.
* If the user writes a V, then we expect a close and allow a release.
* If the user writes anything else, it is ignored.
*/
static ssize_t ubi32_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
size_t i;
unsigned long flags;
/*
* Every write resets the expect_close. The last write
* must be a V to allow shutdown on close.
*/
expect_close = 0;
/*
* Empty writes still ping.
*/
if (!len) {
goto ping;
}
/*
* If nowayout is set, it does not matter if the caller
* is trying to send the magic 'V' we will not allow a
* close to stop us.
*/
if (nowayout) {
goto ping;
}
/*
* See if the program wrote a 'V' and if so disable
* the watchdog on release.
*/
for (i = 0; i < len; i++) {
char c;
if (get_user(c, data + i)) {
return -EFAULT;
}
if (c == 'V') {
expect_close = 42;
}
}
ping:
spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
ubi32_wdt_keepalive();
spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
return len;
}
/*
* ubi32_wdt_ioctl()
* Query the watchdog device.
*
* Query basic information from the device or ping it, as outlined by the
* watchdog API.
*/
static long ubi32_wdt_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ubi32_wdt_info, sizeof(ubi32_wdt_info))) {
return -EFAULT;
}
return 0;
case WDIOC_GETSTATUS: {
unsigned long flags;
int running;
spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
running = ubi32_wdt_running();
spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
return running;
}
case WDIOC_GETBOOTSTATUS:
return ubicom32_get_reset_reason();
case WDIOC_SETOPTIONS: {
unsigned long flags;
int options, ret = -EINVAL;
/*
* The sample application does not pass a pointer
* but directly passes a value of 1 or 2; however
* all of the implementations (and thus probably
* the real applications) pass a pointer to a value.
*
* It should be noted that WDIOC_SETOPTIONS is defined as
* _IOR(WATCHDOG_IOCTL_BASE, 4, int), which means
* that it should be an int and NOT a pointer.
*
* TODO: Examine this code for future chips.
* TODO: Report the sample code defect.
*/
if ((int)p < MIN_PROCESSOR_ADDRESS) {
options = (int)p;
} else {
if (get_user(options, p))
return -EFAULT;
}
spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
if (options & WDIOS_DISABLECARD) {
ubi32_wdt_stop();
ret = 0;
}
if (options & WDIOS_ENABLECARD) {
ubi32_wdt_start();
ret = 0;
}
spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
return ret;
}
case WDIOC_KEEPALIVE: {
unsigned long flags;
spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
ubi32_wdt_keepalive();
spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
return 0;
}
case WDIOC_SETTIMEOUT: {
int new_timeout;
unsigned long flags;
int ret = 0;
if (get_user(new_timeout, p))
return -EFAULT;
spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
ret = ubi32_wdt_set_timeout(new_timeout);
spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
return ret;
}
case WDIOC_GETTIMEOUT:
return put_user(timeout, p);
case WDIOC_GETTIMELEFT: {
unsigned long flags;
int remaining = 0;
spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
remaining = ubi32_wdt_remaining();
spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
return put_user(remaining, p);
}
default:
return -ENOTTY;
}
}
/*
* ubi32_wdt_notify_sys()
* Notification callback function for system events.
*
* Turn off the watchdog during a SYS_DOWN or SYS_HALT.
*/
static int ubi32_wdt_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT) {
unsigned long flags;
spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
ubi32_wdt_stop();
spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
}
return NOTIFY_DONE;
}
#ifdef CONFIG_PM
static int state_before_suspend;
/*
* ubi32_wdt_suspend()
* suspend the watchdog
*
* Remember if the watchdog was running and stop it.
*/
static int ubi32_wdt_suspend(struct platform_device *pdev, pm_message_t state)
{
unsigned long flags;
spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
state_before_suspend = ubi32_wdt_running();
ubi32_wdt_stop();
spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
return 0;
}
/*
* ubi32_wdt_resume()
* Resume the watchdog
*
* If the watchdog was running, turn it back on.
*/
static int ubi32_wdt_resume(struct platform_device *pdev)
{
if (state_before_suspend) {
unsigned long flags;
spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
ubi32_wdt_set_timeout(timeout);
ubi32_wdt_start();
spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
}
return 0;
}
#else
# define ubi32_wdt_suspend NULL
# define ubi32_wdt_resume NULL
#endif
static const struct file_operations ubi32_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = ubi32_wdt_write,
.unlocked_ioctl = ubi32_wdt_ioctl,
.open = ubi32_wdt_open,
.release = ubi32_wdt_release,
};
static struct miscdevice ubi32_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &ubi32_wdt_fops,
};
static struct watchdog_info ubi32_wdt_info = {
.identity = "Ubicom32 Watchdog",
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};
static struct notifier_block ubi32_wdt_notifier = {
.notifier_call = ubi32_wdt_notify_sys,
};
/*
* ubi32_wdt_probe()
* Probe/register the watchdog module
*
* Registers the misc device and notifier handler. Actual device
* initialization is handled by ubi32_wdt_open().
*/
static int __devinit ubi32_wdt_probe(struct platform_device *pdev)
{
int ret;
ret = register_reboot_notifier(&ubi32_wdt_notifier);
if (ret) {
printk(KERN_ERR PFX
"cannot register reboot notifier (err=%d)\n", ret);
return ret;
}
ret = misc_register(&ubi32_wdt_miscdev);
if (ret) {
printk(KERN_ERR PFX
"cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
unregister_reboot_notifier(&ubi32_wdt_notifier);
return ret;
}
printk(KERN_INFO PFX "initialized: timeout=%d sec (nowayout=%d)\n",
timeout, nowayout);
return 0;
}
/*
* ubi32_wdt_remove()
* Uninstall the module
*
* Unregisters the misc device and notifier handler. Actual device
* deinitialization is handled by ubi32_wdt_close().
*/
static int __devexit ubi32_wdt_remove(struct platform_device *pdev)
{
misc_deregister(&ubi32_wdt_miscdev);
unregister_reboot_notifier(&ubi32_wdt_notifier);
return 0;
}
static struct platform_device *ubi32_wdt_device;
static struct platform_driver ubi32_wdt_driver = {
.probe = ubi32_wdt_probe,
.remove = __devexit_p(ubi32_wdt_remove),
.suspend = ubi32_wdt_suspend,
.resume = ubi32_wdt_resume,
.driver = {
.name = WATCHDOG_NAME,
.owner = THIS_MODULE,
},
};
/*
* ubi32_wdt_init()
* Initialize the watchdog.
*
* Checks the module params and registers the platform device & driver.
* Real work is in the platform probe function.
*/
static int __init ubi32_wdt_init(void)
{
unsigned long flags;
int ret;
/*
* Check that the timeout value is within range
*/
spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
ret = ubi32_wdt_set_timeout(timeout);
spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
if (ret) {
return ret;
}
/*
* Since this is an on-chip device and needs no board-specific
* resources, we'll handle all the platform device stuff here.
*/
ret = platform_driver_register(&ubi32_wdt_driver);
if (ret) {
printk(KERN_ERR PFX "unable to register driver\n");
return ret;
}
ubi32_wdt_device = platform_device_register_simple(WATCHDOG_NAME, -1, NULL, 0);
if (IS_ERR(ubi32_wdt_device)) {
printk(KERN_ERR PFX "unable to register device\n");
platform_driver_unregister(&ubi32_wdt_driver);
return PTR_ERR(ubi32_wdt_device);
}
return 0;
}
/*
* ubi32_wdt_exit()
* Deinitialize module
*
* Back out the platform device & driver steps. Real work is in the
* platform remove function.
*/
static void __exit ubi32_wdt_exit(void)
{
platform_device_unregister(ubi32_wdt_device);
platform_driver_unregister(&ubi32_wdt_driver);
}
module_init(ubi32_wdt_init);
module_exit(ubi32_wdt_exit);
MODULE_AUTHOR("Sol Kavy<sol@ubicom.com>");
MODULE_DESCRIPTION("Ubicom32 Watchdog Device Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default="
__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");