[PATCH 1/1] watchdog:improve w83627hf_wdt to timeout in minutes

[Tony Chung <tonychung00@gmail.com>]

The current maximum of 255 seconds is insufficient.
For example, crash dump could take 5+ minutes.

Signed-off-by: Tony Chung <tonychung00@gmail.com>
---
 drivers/watchdog/w83627hf_wdt.c |   73 ++++++++++++++++++++++++++++++--------
 1 files changed, 57 insertions(+), 16 deletions(-)

diff --git a/drivers/watchdog/w83627hf_wdt.c b/drivers/watchdog/w83627hf_wdt.c
index 92f1326..d26adfb 100644
--- a/drivers/watchdog/w83627hf_wdt.c
+++ b/drivers/watchdog/w83627hf_wdt.c
@@ -58,7 +58,7 @@ MODULE_PARM_DESC(wdt_io, "w83627hf/thf WDT io port (default 0x2E)");
 static int timeout = WATCHDOG_TIMEOUT;	/* in seconds */
 module_param(timeout, int, 0);
 MODULE_PARM_DESC(timeout,
-		"Watchdog timeout in seconds. 1 <= timeout <= 255, default="
+		"Watchdog timeout in seconds. 1 <= timeout <= 15300, default="
 				__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
 
 static bool nowayout = WATCHDOG_NOWAYOUT;
@@ -67,6 +67,29 @@ MODULE_PARM_DESC(nowayout,
 		"Watchdog cannot be stopped once started (default="
 				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
+/* timeout unit in minute */
+static bool use_minute;
+static char *unit;
+static int max_timeout = 15300; /* 255*60 seconds */
+
+static inline int wdt_round_secs_to_minute(int t)
+{
+	return (t + 59) / 60;
+}
+
+static inline int wdt_use_minute(int t)
+{
+	if (t > 255) {
+		t = wdt_round_secs_to_minute(t);
+		use_minute = 1;
+		unit = "minutes";
+	} else {
+		use_minute = 0;
+		unit = "secs";
+	}
+	return t;
+}
+
 /*
  *	Kernel methods.
  */
@@ -107,6 +130,23 @@ static void w83627hf_unselect_wd_register(void)
 	outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
 }
 
+/* set CRF5 register */
+static void w83627hf_set_crf5(void)
+{
+	unsigned char t;
+
+	outb_p(0xF5, WDT_EFER); /* Select CRF5 */
+	t = inb_p(WDT_EFDR);      /* read CRF5 */
+	t &= ~0x0C;               /* set second mode & disable keyboard
+				    turning off watchdog */
+	t |= 0x02;		  /* enable the WDTO# output low pulse
+				    to the KBRST# pin (PIN60) */
+	if (use_minute)
+		t |= 0x80;        /* set timeout in minute */
+
+	outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
+}
+
 /* tyan motherboards seem to set F5 to 0x4C ?
  * So explicitly init to appropriate value. */
 
@@ -116,21 +156,16 @@ static void w83627hf_init(void)
 
 	w83627hf_select_wd_register();
 
+	w83627hf_set_crf5();
+
 	outb_p(0xF6, WDT_EFER); /* Select CRF6 */
 	t = inb_p(WDT_EFDR);      /* read CRF6 */
 	if (t != 0) {
-		pr_info("Watchdog already running. Resetting timeout to %d sec\n",
-			timeout);
+		pr_info("Watchdog already running.  Reset timeout to %d %s\n",
+			timeout, unit);
 		outb_p(timeout, WDT_EFDR);    /* Write back to CRF6 */
 	}
 
-	outb_p(0xF5, WDT_EFER); /* Select CRF5 */
-	t = inb_p(WDT_EFDR);      /* read CRF5 */
-	t &= ~0x0C;               /* set second mode & disable keyboard
-				    turning off watchdog */
-	t |= 0x02;		  /* enable the WDTO# output low pulse
-				    to the KBRST# pin (PIN60) */
-	outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
 
 	outb_p(0xF7, WDT_EFER); /* Select CRF7 */
 	t = inb_p(WDT_EFDR);      /* read CRF7 */
@@ -147,6 +182,9 @@ static void wdt_set_time(int timeout)
 
 	w83627hf_select_wd_register();
 
+	if (use_minute)
+		w83627hf_set_crf5();
+
 	outb_p(0xF6, WDT_EFER);    /* Select CRF6 */
 	outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
 
@@ -169,9 +207,9 @@ static int wdt_disable(void)
 
 static int wdt_set_heartbeat(int t)
 {
-	if (t < 1 || t > 255)
+	if (t < 1 || t > max_timeout)
 		return -EINVAL;
-	timeout = t;
+	timeout = wdt_use_minute(t);
 	return 0;
 }
 
@@ -262,9 +300,11 @@ static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		wdt_ping();
 		/* Fall */
 	case WDIOC_GETTIMEOUT:
-		return put_user(timeout, p);
+		timeval = (use_minute) ? timeout * 60 : timeout;
+		return put_user(timeval, p);
 	case WDIOC_GETTIMELEFT:
 		timeval = wdt_get_time();
+		timeval = (use_minute) ? timeval * 60 : timeval;
 		return put_user(timeval, p);
 	default:
 		return -ENOTTY;
@@ -346,7 +386,8 @@ static int __init wdt_init(void)
 
 	if (wdt_set_heartbeat(timeout)) {
 		wdt_set_heartbeat(WATCHDOG_TIMEOUT);
-		pr_info("timeout value must be 1 <= timeout <= 255, using %d\n",
+		pr_info("timeout value must be 1 <= timeout <= %d, using %d\n",
+			max_timeout,
 			WATCHDOG_TIMEOUT);
 	}
 
@@ -371,8 +412,8 @@ static int __init wdt_init(void)
 		goto unreg_reboot;
 	}
 
-	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
-		timeout, nowayout);
+	pr_info("initialized. timeout=%d %s (nowayout=%d)\n",
+		timeout, unit, nowayout);
 
 out:
 	return ret;
-- 
1.7.0.4