diff --git a/drivers/gpu/drm/sprd/sprd_dsi.c b/drivers/gpu/drm/sprd/sprd_dsi.c
index 0b69c140eab36f897d903bd7615c7e4754396762..44a7a579660fd16b63ec81f704133f2515ecc41e 100644
--- a/drivers/gpu/drm/sprd/sprd_dsi.c
+++ b/drivers/gpu/drm/sprd/sprd_dsi.c
@@ -209,7 +209,7 @@ static int regmap_tst_io_read(void *context, u32 reg, u32 *val)
 	return 0;
 }
 
-static struct regmap_bus regmap_tst_io = {
+static const struct regmap_bus regmap_tst_io = {
 	.reg_write = regmap_tst_io_write,
 	.reg_read = regmap_tst_io_read,
 };