[WATCHDOG] bfin: fix max timeout calculation

[linux-beck.git] / drivers / watchdog / bfin_wdt.c

diff --git a/drivers/watchdog/bfin_wdt.c b/drivers/watchdog/bfin_wdt.c
index 067a57cb3f829baf263a9d92f8b345a566c639cc..2159e668751cd7db5e9ddfb39c96984573801539 100644 (file)
--- a/drivers/watchdog/bfin_wdt.c
+++ b/drivers/watchdog/bfin_wdt.c
@@ -1,9 +1,8 @@
 /*
  * Blackfin On-Chip Watchdog Driver
- *  Supports BF53[123]/BF53[467]/BF54[2489]/BF561
  *
  * Originally based on softdog.c
- * Copyright 2006-2007 Analog Devices Inc.
+ * Copyright 2006-2010 Analog Devices Inc.
  * Copyright 2006-2007 Michele d'Amico
  * Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>
  *
@@ -27,10 +26,15 @@
 #include <linux/uaccess.h>
 #include <asm/blackfin.h>
 
-#define stamp(fmt, args...) pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)
+#define stamp(fmt, args...) \
+       pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)
 #define stampit() stamp("here i am")
-#define pr_devinit(fmt, args...) ({ static const __devinitconst char __fmt[] = fmt; printk(__fmt, ## args); })
-#define pr_init(fmt, args...) ({ static const __initconst char __fmt[] = fmt; printk(__fmt, ## args); })
+#define pr_devinit(fmt, args...) \
+       ({ static const __devinitconst char __fmt[] = fmt; \
+       printk(__fmt, ## args); })
+#define pr_init(fmt, args...) \
+       ({ static const __initconst char __fmt[] = fmt; \
+       printk(__fmt, ## args); })
 
 #define WATCHDOG_NAME "bfin-wdt"
 #define PFX WATCHDOG_NAME ": "
@@ -132,13 +136,15 @@ static int bfin_wdt_running(void)
  */
 static int bfin_wdt_set_timeout(unsigned long t)
 {
-       u32 cnt;
+       u32 cnt, max_t, sclk;
        unsigned long flags;
 
-       stampit();
+       sclk = get_sclk();
+       max_t = -1 / sclk;
+       cnt = t * sclk;
+       stamp("maxtimeout=%us newtimeout=%lus (cnt=%#x)", max_t, t, cnt);
 
-       cnt = t * get_sclk();
-       if (cnt < get_sclk()) {
+       if (t > max_t) {
                printk(KERN_WARNING PFX "timeout value is too large\n");
                return -EINVAL;
        }
@@ -476,7 +482,8 @@ static int __init bfin_wdt_init(void)
                return ret;
        }
 
-       bfin_wdt_device = platform_device_register_simple(WATCHDOG_NAME, -1, NULL, 0);
+       bfin_wdt_device = platform_device_register_simple(WATCHDOG_NAME,
+                                                               -1, NULL, 0);
        if (IS_ERR(bfin_wdt_device)) {
                pr_init(KERN_ERR PFX "unable to register device\n");
                platform_driver_unregister(&bfin_wdt_driver);