mpcore_wdt: Add percpu support for ARM11 MPCore watchdogs
George G. Davis
gdavis at mvista.com
Wed Jun 9 11:59:19 EDT 2010
Signed-off-by: George G. Davis <gdavis at mvista.com>
diff --git a/drivers/watchdog/mpcore_wdt.c b/drivers/watchdog/mpcore_wdt.c
index b8ec7ac..d624d8d 100644
--- a/drivers/watchdog/mpcore_wdt.c
+++ b/drivers/watchdog/mpcore_wdt.c
@@ -42,11 +42,14 @@ struct mpcore_wdt {
int irq;
unsigned int perturb;
char expect_close;
+ int margin;
+ int nowayout;
+ int noboot;
+ char name[12];
+ spinlock_t lock;
+ struct miscdevice miscdev;
};
-static struct platform_device *mpcore_wdt_dev;
-static DEFINE_SPINLOCK(wdt_lock);
-
#define TIMER_MARGIN 60
static int mpcore_margin = TIMER_MARGIN;
module_param(mpcore_margin, int, 0);
@@ -97,25 +100,25 @@ static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt)
{
unsigned long count;
- spin_lock(&wdt_lock);
+ spin_lock(&wdt->lock);
/* Assume prescale is set to 256 */
count = __raw_readl(wdt->base + TWD_WDOG_COUNTER);
count = (0xFFFFFFFFU - count) * (HZ / 5);
- count = (count / 256) * mpcore_margin;
+ count = (count / 256) * wdt->margin;
/* Reload the counter */
writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
wdt->perturb = wdt->perturb ? 0 : 1;
- spin_unlock(&wdt_lock);
+ spin_unlock(&wdt->lock);
}
static void mpcore_wdt_stop(struct mpcore_wdt *wdt)
{
- spin_lock(&wdt_lock);
+ spin_lock(&wdt->lock);
writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
writel(0x0, wdt->base + TWD_WDOG_CONTROL);
- spin_unlock(&wdt_lock);
+ spin_unlock(&wdt->lock);
}
static void mpcore_wdt_start(struct mpcore_wdt *wdt)
@@ -125,7 +128,7 @@ static void mpcore_wdt_start(struct mpcore_wdt *wdt)
/* This loads the count register but does NOT start the count yet */
mpcore_wdt_keepalive(wdt);
- if (mpcore_noboot) {
+ if (wdt->noboot) {
/* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
} else {
@@ -134,12 +137,12 @@ static void mpcore_wdt_start(struct mpcore_wdt *wdt)
}
}
-static int mpcore_wdt_set_heartbeat(int t)
+static int mpcore_wdt_set_heartbeat(int *p, int t)
{
if (t < 0x0001 || t > 0xFFFF)
return -EINVAL;
- mpcore_margin = t;
+ *p = t;
return 0;
}
@@ -148,12 +151,13 @@ static int mpcore_wdt_set_heartbeat(int t)
*/
static int mpcore_wdt_open(struct inode *inode, struct file *file)
{
- struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_dev);
+ struct mpcore_wdt *wdt = container_of(file->private_data,
+ struct mpcore_wdt, miscdev);
if (test_and_set_bit(0, &wdt->timer_alive))
return -EBUSY;
- if (nowayout)
+ if (wdt->nowayout)
__module_get(THIS_MODULE);
file->private_data = wdt;
@@ -172,7 +176,7 @@ static int mpcore_wdt_release(struct inode *inode, struct file *file)
/*
* Shut off the timer.
- * Lock it in if it's a module and we set nowayout
+ * Lock it in if it's a module and we set wdt->nowayout
*/
if (wdt->expect_close == 42)
mpcore_wdt_stop(wdt);
@@ -195,7 +199,7 @@ static ssize_t mpcore_wdt_write(struct file *file, const char *data,
* Refresh the timer.
*/
if (len) {
- if (!nowayout) {
+ if (!wdt->nowayout) {
size_t i;
/* In case it was set long ago */
@@ -271,14 +275,14 @@ static long mpcore_wdt_ioctl(struct file *file, unsigned int cmd,
break;
case WDIOC_SETTIMEOUT:
- ret = mpcore_wdt_set_heartbeat(uarg.i);
+ ret = mpcore_wdt_set_heartbeat(&wdt->margin, uarg.i);
if (ret)
break;
mpcore_wdt_keepalive(wdt);
/* Fall */
case WDIOC_GETTIMEOUT:
- uarg.i = mpcore_margin;
+ uarg.i = wdt->margin;
ret = 0;
break;
@@ -318,20 +322,14 @@ static const struct file_operations mpcore_wdt_fops = {
.release = mpcore_wdt_release,
};
-static struct miscdevice mpcore_wdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &mpcore_wdt_fops,
-};
-
static int __devinit mpcore_wdt_probe(struct platform_device *dev)
{
struct mpcore_wdt *wdt;
struct resource *res;
int ret;
- /* We only accept one device, and it must have an id of -1 */
- if (dev->id != -1)
+ /* Support up to four devices having an id of 0..3 */
+ if (dev->id < 0 || dev->id > 3)
return -ENODEV;
res = platform_get_resource(dev, IORESOURCE_MEM, 0);
@@ -358,8 +356,12 @@ static int __devinit mpcore_wdt_probe(struct platform_device *dev)
goto err_free;
}
- mpcore_wdt_miscdev.parent = &dev->dev;
- ret = misc_register(&mpcore_wdt_miscdev);
+ snprintf(wdt->name, ARRAY_SIZE(wdt->name), "watchdog%d", dev->id);
+ wdt->miscdev.parent = &dev->dev;
+ wdt->miscdev.minor = MISC_DYNAMIC_MINOR,
+ wdt->miscdev.name = wdt->name,
+ wdt->miscdev.fops = &mpcore_wdt_fops,
+ ret = misc_register(&wdt->miscdev);
if (ret) {
dev_printk(KERN_ERR, wdt->dev,
"cannot register miscdev on minor=%d (err=%d)\n",
@@ -367,22 +369,28 @@ static int __devinit mpcore_wdt_probe(struct platform_device *dev)
goto err_misc;
}
- ret = request_irq(wdt->irq, mpcore_wdt_fire, IRQF_DISABLED,
- "mpcore_wdt", wdt);
+ ret = request_irq(wdt->irq, mpcore_wdt_fire,
+ IRQF_DISABLED |
+ IRQF_SHARED |
+ IRQF_NOBALANCING |
+ IRQF_PERCPU, "mpcore_wdt", wdt);
if (ret) {
dev_printk(KERN_ERR, wdt->dev,
"cannot register IRQ%d for watchdog\n", wdt->irq);
goto err_irq;
}
+ spin_lock_init(&wdt->lock);
+ wdt->margin = mpcore_margin;
+ wdt->nowayout = nowayout;
+ wdt->noboot = mpcore_noboot;
mpcore_wdt_stop(wdt);
platform_set_drvdata(dev, wdt);
- mpcore_wdt_dev = dev;
return 0;
err_irq:
- misc_deregister(&mpcore_wdt_miscdev);
+ misc_deregister(&wdt->miscdev);
err_misc:
iounmap(wdt->base);
err_free:
@@ -397,9 +405,7 @@ static int __devexit mpcore_wdt_remove(struct platform_device *dev)
platform_set_drvdata(dev, NULL);
- misc_deregister(&mpcore_wdt_miscdev);
-
- mpcore_wdt_dev = NULL;
+ misc_deregister(&wdt->miscdev);
free_irq(wdt->irq, wdt);
iounmap(wdt->base);
@@ -421,7 +427,7 @@ static struct platform_driver mpcore_wdt_driver = {
};
static char banner[] __initdata = KERN_INFO "MPcore Watchdog Timer: 0.1. "
- "mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n";
+ "mpcore_noboot=%d mpcore_margin=%d sec (nowayout=%d)\n";
static int __init mpcore_wdt_init(void)
{
@@ -429,8 +435,8 @@ static int __init mpcore_wdt_init(void)
* Check that the margin value is within it's range;
* if not reset to the default
*/
- if (mpcore_wdt_set_heartbeat(mpcore_margin)) {
- mpcore_wdt_set_heartbeat(TIMER_MARGIN);
+ if (mpcore_wdt_set_heartbeat(&mpcore_margin, mpcore_margin)) {
+ mpcore_wdt_set_heartbeat(&mpcore_margin, TIMER_MARGIN);
printk(KERN_INFO "mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n",
TIMER_MARGIN);
}
HTH!
--
Regards,
George
>
> Thanks,
> John
>
>
>
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