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linux/drivers/watchdog/orion5x_wdt.c
Thomas Reitmayr 6462c6160a [ARM] orion5x: Change names of defines for Reset-Out-Mask register 
The name of the define for the Reset-Out-Mask register as well as its
bit for the watchdog reset are changed to match the names used for
Kirkwood (which in turn match the processor specification more
closely). There is no functional change.

This patch prepares for adding orion5x_wdt as a platform device to
Kirkwood.

Signed-off-by: Thomas Reitmayr <treitmayr@devbase.at>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
2009-06-08 13:04:59 -04:00

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/*
* drivers/watchdog/orion5x_wdt.c
*
* Watchdog driver for Orion5x processors
*
* Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/init.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <mach/bridge-regs.h>
#include <plat/orion5x_wdt.h>
/*
* Watchdog timer block registers.
*/
#define TIMER_CTRL (TIMER_VIRT_BASE + 0x0000)
#define WDT_EN 0x0010
#define WDT_VAL (TIMER_VIRT_BASE + 0x0024)
#define WDT_MAX_CYCLE_COUNT 0xffffffff
#define WDT_IN_USE 0
#define WDT_OK_TO_CLOSE 1
static int nowayout = WATCHDOG_NOWAYOUT;
static int heartbeat = -1; /* module parameter (seconds) */
static unsigned int wdt_max_duration; /* (seconds) */
static unsigned int wdt_tclk;
static unsigned long wdt_status;
static spinlock_t wdt_lock;
static void orion5x_wdt_ping(void)
{
spin_lock(&wdt_lock);
/* Reload watchdog duration */
writel(wdt_tclk * heartbeat, WDT_VAL);
spin_unlock(&wdt_lock);
}
static void orion5x_wdt_enable(void)
{
u32 reg;
spin_lock(&wdt_lock);
/* Set watchdog duration */
writel(wdt_tclk * heartbeat, WDT_VAL);
/* Clear watchdog timer interrupt */
reg = readl(BRIDGE_CAUSE);
reg &= ~WDT_INT_REQ;
writel(reg, BRIDGE_CAUSE);
/* Enable watchdog timer */
reg = readl(TIMER_CTRL);
reg |= WDT_EN;
writel(reg, TIMER_CTRL);
/* Enable reset on watchdog */
reg = readl(RSTOUTn_MASK);
reg |= WDT_RESET_OUT_EN;
writel(reg, RSTOUTn_MASK);
spin_unlock(&wdt_lock);
}
static void orion5x_wdt_disable(void)
{
u32 reg;
spin_lock(&wdt_lock);
/* Disable reset on watchdog */
reg = readl(RSTOUTn_MASK);
reg &= ~WDT_RESET_OUT_EN;
writel(reg, RSTOUTn_MASK);
/* Disable watchdog timer */
reg = readl(TIMER_CTRL);
reg &= ~WDT_EN;
writel(reg, TIMER_CTRL);
spin_unlock(&wdt_lock);
}
static int orion5x_wdt_get_timeleft(int *time_left)
{
spin_lock(&wdt_lock);
*time_left = readl(WDT_VAL) / wdt_tclk;
spin_unlock(&wdt_lock);
return 0;
}
static int orion5x_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(WDT_IN_USE, &wdt_status))
return -EBUSY;
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
orion5x_wdt_enable();
return nonseekable_open(inode, file);
}
static ssize_t orion5x_wdt_write(struct file *file, const char *data,
size_t len, loff_t *ppos)
{
if (len) {
if (!nowayout) {
size_t i;
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
set_bit(WDT_OK_TO_CLOSE, &wdt_status);
}
}
orion5x_wdt_ping();
}
return len;
}
static int orion5x_wdt_settimeout(int new_time)
{
if ((new_time <= 0) || (new_time > wdt_max_duration))
return -EINVAL;
/* Set new watchdog time to be used when
* orion5x_wdt_enable() or orion5x_wdt_ping() is called. */
heartbeat = new_time;
return 0;
}
static const struct watchdog_info ident = {
.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING,
.identity = "Orion5x Watchdog",
};
static long orion5x_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int ret = -ENOTTY;
int time;
switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user((struct watchdog_info *)arg, &ident,
sizeof(ident)) ? -EFAULT : 0;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
ret = put_user(0, (int *)arg);
break;
case WDIOC_KEEPALIVE:
orion5x_wdt_ping();
ret = 0;
break;
case WDIOC_SETTIMEOUT:
ret = get_user(time, (int *)arg);
if (ret)
break;
if (orion5x_wdt_settimeout(time)) {
ret = -EINVAL;
break;
}
orion5x_wdt_ping();
/* Fall through */
case WDIOC_GETTIMEOUT:
ret = put_user(heartbeat, (int *)arg);
break;
case WDIOC_GETTIMELEFT:
if (orion5x_wdt_get_timeleft(&time)) {
ret = -EINVAL;
break;
}
ret = put_user(time, (int *)arg);
break;
}
return ret;
}
static int orion5x_wdt_release(struct inode *inode, struct file *file)
{
if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
orion5x_wdt_disable();
else
printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
"timer will not stop\n");
clear_bit(WDT_IN_USE, &wdt_status);
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
return 0;
}
static const struct file_operations orion5x_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = orion5x_wdt_write,
.unlocked_ioctl = orion5x_wdt_ioctl,
.open = orion5x_wdt_open,
.release = orion5x_wdt_release,
};
static struct miscdevice orion5x_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &orion5x_wdt_fops,
};
static int __devinit orion5x_wdt_probe(struct platform_device *pdev)
{
struct orion5x_wdt_platform_data *pdata = pdev->dev.platform_data;
int ret;
if (pdata) {
wdt_tclk = pdata->tclk;
} else {
printk(KERN_ERR "Orion5x Watchdog misses platform data\n");
return -ENODEV;
}
if (orion5x_wdt_miscdev.parent)
return -EBUSY;
orion5x_wdt_miscdev.parent = &pdev->dev;
wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk;
if (orion5x_wdt_settimeout(heartbeat))
heartbeat = wdt_max_duration;
ret = misc_register(&orion5x_wdt_miscdev);
if (ret)
return ret;
printk(KERN_INFO "Orion5x Watchdog Timer: Initial timeout %d sec%s\n",
heartbeat, nowayout ? ", nowayout" : "");
return 0;
}
static int __devexit orion5x_wdt_remove(struct platform_device *pdev)
{
int ret;
if (test_bit(WDT_IN_USE, &wdt_status)) {
orion5x_wdt_disable();
clear_bit(WDT_IN_USE, &wdt_status);
}
ret = misc_deregister(&orion5x_wdt_miscdev);
if (!ret)
orion5x_wdt_miscdev.parent = NULL;
return ret;
}
static void orion5x_wdt_shutdown(struct platform_device *pdev)
{
if (test_bit(WDT_IN_USE, &wdt_status))
orion5x_wdt_disable();
}
static struct platform_driver orion5x_wdt_driver = {
.probe = orion5x_wdt_probe,
.remove = __devexit_p(orion5x_wdt_remove),
.shutdown = orion5x_wdt_shutdown,
.driver = {
.owner = THIS_MODULE,
.name = "orion5x_wdt",
},
};
static int __init orion5x_wdt_init(void)
{
spin_lock_init(&wdt_lock);
return platform_driver_register(&orion5x_wdt_driver);
}
static void __exit orion5x_wdt_exit(void)
{
platform_driver_unregister(&orion5x_wdt_driver);
}
module_init(orion5x_wdt_init);
module_exit(orion5x_wdt_exit);
MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
MODULE_DESCRIPTION("Orion5x Processor Watchdog");
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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