diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c b/drivers/media/platform/rcar-vin/rcar-dma.c
index 482d89bae657..905d975b2909 100644
--- a/drivers/media/platform/rcar-vin/rcar-dma.c
+++ b/drivers/media/platform/rcar-vin/rcar-dma.c
@@ -16,6 +16,7 @@
 
 #include <linux/delay.h>
 #include <linux/interrupt.h>
+#include <linux/pm_runtime.h>
 
 #include <media/videobuf2-dma-contig.h>
 
@@ -1157,3 +1158,39 @@ error:
 
 	return ret;
 }
+
+/* -----------------------------------------------------------------------------
+ * Gen3 CHSEL manipulation
+ */
+
+/*
+ * There is no need to have locking around changing the routing
+ * as it's only possible to do so when no VIN in the group is
+ * streaming so nothing can race with the VNMC register.
+ */
+int rvin_set_channel_routing(struct rvin_dev *vin, u8 chsel)
+{
+	u32 ifmd, vnmc;
+	int ret;
+
+	ret = pm_runtime_get_sync(vin->dev);
+	if (ret < 0)
+		return ret;
+
+	/* Make register writes take effect immediately. */
+	vnmc = rvin_read(vin, VNMC_REG);
+	rvin_write(vin, vnmc & ~VNMC_VUP, VNMC_REG);
+
+	ifmd = VNCSI_IFMD_DES1 | VNCSI_IFMD_DES0 | VNCSI_IFMD_CSI_CHSEL(chsel);
+
+	rvin_write(vin, ifmd, VNCSI_IFMD_REG);
+
+	vin_dbg(vin, "Set IFMD 0x%x\n", ifmd);
+
+	/* Restore VNMC. */
+	rvin_write(vin, vnmc, VNMC_REG);
+
+	pm_runtime_put(vin->dev);
+
+	return ret;
+}
diff --git a/drivers/media/platform/rcar-vin/rcar-vin.h b/drivers/media/platform/rcar-vin/rcar-vin.h
index 321283f1618a..c19ddc5e08cb 100644
--- a/drivers/media/platform/rcar-vin/rcar-vin.h
+++ b/drivers/media/platform/rcar-vin/rcar-vin.h
@@ -169,4 +169,6 @@ const struct rvin_video_format *rvin_format_from_pixel(u32 pixelformat);
 /* Cropping, composing and scaling */
 void rvin_crop_scale_comp(struct rvin_dev *vin);
 
+int rvin_set_channel_routing(struct rvin_dev *vin, u8 chsel);
+
 #endif