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path: root/drivers/watchdog/rc32434_wdt.c
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Diffstat (limited to 'drivers/watchdog/rc32434_wdt.c')
-rw-r--r--drivers/watchdog/rc32434_wdt.c168
1 files changed, 69 insertions, 99 deletions
diff --git a/drivers/watchdog/rc32434_wdt.c b/drivers/watchdog/rc32434_wdt.c
index 57027f4653c..f3553fa40b1 100644
--- a/drivers/watchdog/rc32434_wdt.c
+++ b/drivers/watchdog/rc32434_wdt.c
@@ -34,104 +34,89 @@
#include <asm/time.h>
#include <asm/mach-rc32434/integ.h>
-#define MAX_TIMEOUT 20
-#define RC32434_WDT_INTERVAL (15 * HZ)
-
-#define VERSION "0.2"
+#define VERSION "0.4"
static struct {
- struct completion stop;
- int running;
- struct timer_list timer;
- int queue;
- int default_ticks;
unsigned long inuse;
} rc32434_wdt_device;
static struct integ __iomem *wdt_reg;
-static int ticks = 100 * HZ;
static int expect_close;
-static int timeout;
+
+/* Board internal clock speed in Hz,
+ * the watchdog timer ticks at. */
+extern unsigned int idt_cpu_freq;
+
+/* translate wtcompare value to seconds and vice versa */
+#define WTCOMP2SEC(x) (x / idt_cpu_freq)
+#define SEC2WTCOMP(x) (x * idt_cpu_freq)
+
+/* Use a default timeout of 20s. This should be
+ * safe for CPU clock speeds up to 400MHz, as
+ * ((2 ^ 32) - 1) / (400MHz / 2) = 21s. */
+#define WATCHDOG_TIMEOUT 20
+
+static int timeout = WATCHDOG_TIMEOUT;
static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+/* apply or and nand masks to data read from addr and write back */
+#define SET_BITS(addr, or, nand) \
+ writel((readl(&addr) | or) & ~nand, &addr)
static void rc32434_wdt_start(void)
{
- u32 val;
-
- if (!rc32434_wdt_device.inuse) {
- writel(0, &wdt_reg->wtcount);
+ u32 or, nand;
- val = RC32434_ERR_WRE;
- writel(readl(&wdt_reg->errcs) | val, &wdt_reg->errcs);
+ /* zero the counter before enabling */
+ writel(0, &wdt_reg->wtcount);
- val = RC32434_WTC_EN;
- writel(readl(&wdt_reg->wtc) | val, &wdt_reg->wtc);
- }
- rc32434_wdt_device.running++;
-}
+ /* don't generate a non-maskable interrupt,
+ * do a warm reset instead */
+ nand = 1 << RC32434_ERR_WNE;
+ or = 1 << RC32434_ERR_WRE;
-static void rc32434_wdt_stop(void)
-{
- u32 val;
+ /* reset the ERRCS timeout bit in case it's set */
+ nand |= 1 << RC32434_ERR_WTO;
- if (rc32434_wdt_device.running) {
+ SET_BITS(wdt_reg->errcs, or, nand);
- val = ~RC32434_WTC_EN;
- writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);
+ /* reset WTC timeout bit and enable WDT */
+ nand = 1 << RC32434_WTC_TO;
+ or = 1 << RC32434_WTC_EN;
- val = ~RC32434_ERR_WRE;
- writel(readl(&wdt_reg->errcs) & val, &wdt_reg->errcs);
+ SET_BITS(wdt_reg->wtc, or, nand);
+}
- rc32434_wdt_device.running = 0;
- }
+static void rc32434_wdt_stop(void)
+{
+ /* Disable WDT */
+ SET_BITS(wdt_reg->wtc, 0, 1 << RC32434_WTC_EN);
}
-static void rc32434_wdt_set(int new_timeout)
+static int rc32434_wdt_set(int new_timeout)
{
- u32 cmp = new_timeout * HZ;
- u32 state, val;
+ int max_to = WTCOMP2SEC((u32)-1);
+ if (new_timeout < 0 || new_timeout > max_to) {
+ printk(KERN_ERR KBUILD_MODNAME
+ ": timeout value must be between 0 and %d",
+ max_to);
+ return -EINVAL;
+ }
timeout = new_timeout;
- /*
- * store and disable WTC
- */
- state = (u32)(readl(&wdt_reg->wtc) & RC32434_WTC_EN);
- val = ~RC32434_WTC_EN;
- writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);
-
- writel(0, &wdt_reg->wtcount);
- writel(cmp, &wdt_reg->wtcompare);
-
- /*
- * restore WTC
- */
-
- writel(readl(&wdt_reg->wtc) | state, &wdt_reg);
-}
+ writel(SEC2WTCOMP(timeout), &wdt_reg->wtcompare);
-static void rc32434_wdt_reset(void)
-{
- ticks = rc32434_wdt_device.default_ticks;
+ return 0;
}
-static void rc32434_wdt_update(unsigned long unused)
+static void rc32434_wdt_ping(void)
{
- if (rc32434_wdt_device.running)
- ticks--;
-
writel(0, &wdt_reg->wtcount);
-
- if (rc32434_wdt_device.queue && ticks)
- mod_timer(&rc32434_wdt_device.timer,
- jiffies + RC32434_WDT_INTERVAL);
- else
- complete(&rc32434_wdt_device.stop);
}
static int rc32434_wdt_open(struct inode *inode, struct file *file)
@@ -142,19 +127,23 @@ static int rc32434_wdt_open(struct inode *inode, struct file *file)
if (nowayout)
__module_get(THIS_MODULE);
+ rc32434_wdt_start();
+ rc32434_wdt_ping();
+
return nonseekable_open(inode, file);
}
static int rc32434_wdt_release(struct inode *inode, struct file *file)
{
- if (expect_close && nowayout == 0) {
+ if (expect_close == 42) {
rc32434_wdt_stop();
printk(KERN_INFO KBUILD_MODNAME ": disabling watchdog timer\n");
module_put(THIS_MODULE);
- } else
+ } else {
printk(KERN_CRIT KBUILD_MODNAME
": device closed unexpectedly. WDT will not stop !\n");
-
+ rc32434_wdt_ping();
+ }
clear_bit(0, &rc32434_wdt_device.inuse);
return 0;
}
@@ -174,10 +163,10 @@ static ssize_t rc32434_wdt_write(struct file *file, const char *data,
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
- expect_close = 1;
+ expect_close = 42;
}
}
- rc32434_wdt_update(0);
+ rc32434_wdt_ping();
return len;
}
return 0;
@@ -197,11 +186,11 @@ static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd,
};
switch (cmd) {
case WDIOC_KEEPALIVE:
- rc32434_wdt_reset();
+ rc32434_wdt_ping();
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
- value = readl(&wdt_reg->wtcount);
+ value = 0;
if (copy_to_user(argp, &value, sizeof(int)))
return -EFAULT;
break;
@@ -218,6 +207,7 @@ static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd,
break;
case WDIOS_DISABLECARD:
rc32434_wdt_stop();
+ break;
default:
return -EINVAL;
}
@@ -225,11 +215,9 @@ static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd,
case WDIOC_SETTIMEOUT:
if (copy_from_user(&new_timeout, argp, sizeof(int)))
return -EFAULT;
- if (new_timeout < 1)
+ if (rc32434_wdt_set(new_timeout))
return -EINVAL;
- if (new_timeout > MAX_TIMEOUT)
- return -EINVAL;
- rc32434_wdt_set(new_timeout);
+ /* Fall through */
case WDIOC_GETTIMEOUT:
return copy_to_user(argp, &timeout, sizeof(int));
default:
@@ -254,15 +242,15 @@ static struct miscdevice rc32434_wdt_miscdev = {
.fops = &rc32434_wdt_fops,
};
-static char banner[] = KERN_INFO KBUILD_MODNAME
+static char banner[] __devinitdata = KERN_INFO KBUILD_MODNAME
": Watchdog Timer version " VERSION ", timer margin: %d sec\n";
-static int rc32434_wdt_probe(struct platform_device *pdev)
+static int __devinit rc32434_wdt_probe(struct platform_device *pdev)
{
int ret;
struct resource *r;
- r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb500_wdt_res");
+ r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb532_wdt_res");
if (!r) {
printk(KERN_ERR KBUILD_MODNAME
"failed to retrieve resources\n");
@@ -277,24 +265,12 @@ static int rc32434_wdt_probe(struct platform_device *pdev)
}
ret = misc_register(&rc32434_wdt_miscdev);
-
if (ret < 0) {
printk(KERN_ERR KBUILD_MODNAME
"failed to register watchdog device\n");
goto unmap;
}
- init_completion(&rc32434_wdt_device.stop);
- rc32434_wdt_device.queue = 0;
-
- clear_bit(0, &rc32434_wdt_device.inuse);
-
- setup_timer(&rc32434_wdt_device.timer, rc32434_wdt_update, 0L);
-
- rc32434_wdt_device.default_ticks = ticks;
-
- rc32434_wdt_start();
-
printk(banner, timeout);
return 0;
@@ -304,23 +280,17 @@ unmap:
return ret;
}
-static int rc32434_wdt_remove(struct platform_device *pdev)
+static int __devexit rc32434_wdt_remove(struct platform_device *pdev)
{
- if (rc32434_wdt_device.queue) {
- rc32434_wdt_device.queue = 0;
- wait_for_completion(&rc32434_wdt_device.stop);
- }
misc_deregister(&rc32434_wdt_miscdev);
-
iounmap(wdt_reg);
-
return 0;
}
static struct platform_driver rc32434_wdt = {
.probe = rc32434_wdt_probe,
- .remove = rc32434_wdt_remove,
- .driver = {
+ .remove = __devexit_p(rc32434_wdt_remove),
+ .driver = {
.name = "rc32434_wdt",
}
};
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-15 01:06:40 +0000