powerpc: Fix Book-E watchdog timer interval setting

This patch fixes the setting of the Book-E watchdog timer interval setup
on initialization and by ioctl().

On initialization the period bits have to be masked before setting
a new period.

In WDIOC_SETTIMEOUT ioctl we have to use the correct mask.

Signed-off-by: Matthias Fuchs <matthias.fuchs@esd-electronics.com>
Acked-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/watchdog/booke_wdt.c b/drivers/watchdog/booke_wdt.c
index c3b78a76f173..225398fd5049 100644
--- a/drivers/watchdog/booke_wdt.c
+++ b/drivers/watchdog/booke_wdt.c
@@ -42,8 +42,10 @@ u32 booke_wdt_period = WDT_PERIOD_DEFAULT;
 
 #ifdef  CONFIG_FSL_BOOKE
 #define WDTP(x)         ((((63-x)&0x3)<<30)|(((63-x)&0x3c)<<15))
+#define WDTP_MASK       (WDTP(0))
 #else
 #define WDTP(x)         (TCR_WP(x))
+#define WDTP_MASK       (TCR_WP_MASK)
 #endif
 
 static DEFINE_SPINLOCK(booke_wdt_lock);
@@ -65,6 +67,7 @@ static void __booke_wdt_enable(void *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));
 
         mtspr(SPRN_TCR, val);
@@ -114,7 +117,7 @@ static long booke_wdt_ioctl(struct file *file,
         case WDIOC_SETTIMEOUT:
                 if (get_user(booke_wdt_period, p))
                         return -EFAULT;
-                mtspr(SPRN_TCR, (mfspr(SPRN_TCR) & ~WDTP(0)) |
+                mtspr(SPRN_TCR, (mfspr(SPRN_TCR) & ~WDTP_MASK) |
                                                 WDTP(booke_wdt_period));
                 return 0;
         case WDIOC_GETTIMEOUT: