diff --git a/drivers/mfd/sm501.c b/drivers/mfd/sm501.c
index 81e6d09..1f9233b 100644
--- a/drivers/mfd/sm501.c
+++ b/drivers/mfd/sm501.c
@@ -514,9 +514,9 @@
 	unsigned long mode = smc501_readl(sm->regs + SM501_POWER_MODE_CONTROL);
 	unsigned long gate = smc501_readl(sm->regs + SM501_CURRENT_GATE);
 	unsigned long clock = smc501_readl(sm->regs + SM501_CURRENT_CLOCK);
-	unsigned char reg;
 	unsigned int pll_reg = 0;
 	unsigned long sm501_freq; /* the actual frequency achieved */
+	u64 reg;
 
 	struct sm501_clock to;