booke/watchdog: refine and clean up the codes

Basically, this patch does the following:
1. Move the codes of parsing boot parameters from setup-common.c
   to driver. In this way, code reader can know directly that
   there are boot parameters that can change the timeout.
2. Make boot parameter 'booke_wdt_period' effective.
   currently, when driver is loaded, default timeout is always
   being used in stead of booke_wdt_period.
3. Wrap up the watchdog timeout in device struct and clean up
   unnecessary codes.

Signed-off-by: Tang Yuantian <yuantian.tang@freescale.com>
Acked-by: Scott Wood <scottwood@freescale.com>
Reviewed-by: Li Yang <leoli@freescale.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

arch/powerpc/kernel/setup-common.c

@@ -718,33 +718,6 @@ static int powerpc_debugfs_init(void)
 arch_initcall(powerpc_debugfs_init);
 #endif
 
-#ifdef CONFIG_BOOKE_WDT
-extern u32 booke_wdt_enabled;
-extern u32 booke_wdt_period;
-
-/* Checks wdt=x and wdt_period=xx command-line option */
-notrace int __init early_parse_wdt(char *p)
-{
-	if (p && strncmp(p, "0", 1) != 0)
-		booke_wdt_enabled = 1;
-
-	return 0;
-}
-early_param("wdt", early_parse_wdt);
-
-int __init early_parse_wdt_period(char *p)
-{
-	unsigned long ret;
-	if (p) {
-		if (!kstrtol(p, 0, &ret))
-			booke_wdt_period = ret;
-	}
-
-	return 0;
-}
-early_param("wdt_period", early_parse_wdt_period);
-#endif	/* CONFIG_BOOKE_WDT */
-
 void ppc_printk_progress(char *s, unsigned short hex)
 {
 	pr_info("%s\n", s);

drivers/watchdog/booke_wdt.c

@@ -41,6 +41,28 @@ u32 booke_wdt_period = CONFIG_BOOKE_WDT_DEFAULT_TIMEOUT;
 #define WDTP_MASK	(TCR_WP_MASK)
 #endif
 
+/* Checks wdt=x and wdt_period=xx command-line option */
+notrace int __init early_parse_wdt(char *p)
+{
+	if (p && strncmp(p, "0", 1) != 0)
+		booke_wdt_enabled = 1;
+
+	return 0;
+}
+early_param("wdt", early_parse_wdt);
+
+int __init early_parse_wdt_period(char *p)
+{
+	unsigned long ret;
+	if (p) {
+		if (!kstrtol(p, 0, &ret))
+			booke_wdt_period = ret;
+	}
+
+	return 0;
+}
+early_param("wdt_period", early_parse_wdt_period);
+
 #ifdef CONFIG_PPC_FSL_BOOK3E
 
 /* For the specified period, determine the number of seconds
@@ -103,17 +125,18 @@ static unsigned int sec_to_period(unsigned int secs)
 static void __booke_wdt_set(void *data)
 {
 	u32 val;
+	struct watchdog_device *wdog = data;
 
 	val = mfspr(SPRN_TCR);
 	val &= ~WDTP_MASK;
-	val |= WDTP(booke_wdt_period);
+	val |= WDTP(sec_to_period(wdog->timeout));
 
 	mtspr(SPRN_TCR, val);
 }
 
-static void booke_wdt_set(void)
+static void booke_wdt_set(void *data)
 {
-	on_each_cpu(__booke_wdt_set, NULL, 0);
+	on_each_cpu(__booke_wdt_set, data, 0);
 }
 
 static void __booke_wdt_ping(void *data)
@@ -131,12 +154,13 @@ static int booke_wdt_ping(struct watchdog_device *wdog)
 static void __booke_wdt_enable(void *data)
 {
 	u32 val;
+	struct watchdog_device *wdog = data;
 
 	/* clear status before enabling watchdog */
 	__booke_wdt_ping(NULL);
 	val = mfspr(SPRN_TCR);
 	val &= ~WDTP_MASK;
-	val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(booke_wdt_period));
+	val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(sec_to_period(wdog->timeout)));
 
 	mtspr(SPRN_TCR, val);
 }
@@ -162,25 +186,17 @@ static void __booke_wdt_disable(void *data)
 
 }
 
-static void __booke_wdt_start(struct watchdog_device *wdog)
+static int booke_wdt_start(struct watchdog_device *wdog)
 {
-	on_each_cpu(__booke_wdt_enable, NULL, 0);
+	on_each_cpu(__booke_wdt_enable, wdog, 0);
 	pr_debug("watchdog enabled (timeout = %u sec)\n", wdog->timeout);
-}
 
-static int booke_wdt_start(struct watchdog_device *wdog)
-{
-	if (booke_wdt_enabled == 0) {
-		booke_wdt_enabled = 1;
-		__booke_wdt_start(wdog);
-	}
 	return 0;
 }
 
 static int booke_wdt_stop(struct watchdog_device *wdog)
 {
 	on_each_cpu(__booke_wdt_disable, NULL, 0);
-	booke_wdt_enabled = 0;
 	pr_debug("watchdog disabled\n");
 
 	return 0;
@@ -191,9 +207,8 @@ static int booke_wdt_set_timeout(struct watchdog_device *wdt_dev,
 {
 	if (timeout > MAX_WDT_TIMEOUT)
 		return -EINVAL;
-	booke_wdt_period = sec_to_period(timeout);
 	wdt_dev->timeout = timeout;
-	booke_wdt_set();
+	booke_wdt_set(wdt_dev);
 
 	return 0;
 }
@@ -231,10 +246,10 @@ static int __init booke_wdt_init(void)
 	pr_info("powerpc book-e watchdog driver loaded\n");
 	booke_wdt_info.firmware_version = cur_cpu_spec->pvr_value;
 	booke_wdt_set_timeout(&booke_wdt_dev,
-			      period_to_sec(CONFIG_BOOKE_WDT_DEFAULT_TIMEOUT));
+			      period_to_sec(booke_wdt_period));
 	watchdog_set_nowayout(&booke_wdt_dev, nowayout);
 	if (booke_wdt_enabled)
-		__booke_wdt_start(&booke_wdt_dev);
+		booke_wdt_start(&booke_wdt_dev);
 
 	ret = watchdog_register_device(&booke_wdt_dev);