diff --git a/drivers/clocksource/sh_mtu2.c b/drivers/clocksource/sh_mtu2.c
index 354b27d14a19..62812f80b5cc 100644
--- a/drivers/clocksource/sh_mtu2.c
+++ b/drivers/clocksource/sh_mtu2.c
@@ -328,12 +328,13 @@ static int sh_mtu2_register(struct sh_mtu2_channel *ch, const char *name)
 	return 0;
 }
 
+static const unsigned int sh_mtu2_channel_offsets[] = {
+	0x300, 0x380, 0x000,
+};
+
 static int sh_mtu2_setup_channel(struct sh_mtu2_channel *ch, unsigned int index,
 				 struct sh_mtu2_device *mtu)
 {
-	static const unsigned int channel_offsets[] = {
-		0x300, 0x380, 0x000,
-	};
 	char name[6];
 	int irq;
 	int ret;
@@ -356,7 +357,7 @@ static int sh_mtu2_setup_channel(struct sh_mtu2_channel *ch, unsigned int index,
 		return ret;
 	}
 
-	ch->base = mtu->mapbase + channel_offsets[index];
+	ch->base = mtu->mapbase + sh_mtu2_channel_offsets[index];
 	ch->index = index;
 
 	return sh_mtu2_register(ch, dev_name(&mtu->pdev->dev));
@@ -408,7 +409,12 @@ static int sh_mtu2_setup(struct sh_mtu2_device *mtu,
 	}
 
 	/* Allocate and setup the channels. */
-	mtu->num_channels = 3;
+	ret = platform_irq_count(pdev);
+	if (ret < 0)
+		goto err_unmap;
+
+	mtu->num_channels = min_t(unsigned int, ret,
+				  ARRAY_SIZE(sh_mtu2_channel_offsets));
 
 	mtu->channels = kcalloc(mtu->num_channels, sizeof(*mtu->channels),
 				GFP_KERNEL);