diff --git a/drivers/gpu/drm/sti/sti_compositor.c b/drivers/gpu/drm/sti/sti_compositor.c
index 134201ecc6fd..a8441ae2623a 100644
--- a/drivers/gpu/drm/sti/sti_compositor.c
+++ b/drivers/gpu/drm/sti/sti_compositor.c
@@ -25,7 +25,7 @@
 /*
  * stiH407 compositor properties
  */
-struct sti_compositor_data stih407_compositor_data = {
+static const struct sti_compositor_data stih407_compositor_data = {
 	.nb_subdev = 8,
 	.subdev_desc = {
 			{STI_CURSOR_SUBDEV, (int)STI_CURSOR, 0x000},
@@ -46,7 +46,7 @@ struct sti_compositor_data stih407_compositor_data = {
  * Moreover, GDPx is different for Main and Aux Mixer. So this subdev map does
  * not fit for stiH416 if we want to enable the MIXER_AUX.
  */
-struct sti_compositor_data stih416_compositor_data = {
+static const struct sti_compositor_data stih416_compositor_data = {
 	.nb_subdev = 3,
 	.subdev_desc = {
 			{STI_GPD_SUBDEV, (int)STI_GDP_0, 0x100},
diff --git a/drivers/gpu/drm/sti/sti_cursor.c b/drivers/gpu/drm/sti/sti_cursor.c
index 3b53f7f2e3fc..651f231c4615 100644
--- a/drivers/gpu/drm/sti/sti_cursor.c
+++ b/drivers/gpu/drm/sti/sti_cursor.c
@@ -345,7 +345,7 @@ static int sti_cursor_late_register(struct drm_plane *drm_plane)
 	return cursor_debugfs_init(cursor, drm_plane->dev->primary);
 }
 
-struct drm_plane_funcs sti_cursor_plane_helpers_funcs = {
+static const struct drm_plane_funcs sti_cursor_plane_helpers_funcs = {
 	.update_plane = drm_atomic_helper_update_plane,
 	.disable_plane = drm_atomic_helper_disable_plane,
 	.destroy = sti_cursor_destroy,
diff --git a/drivers/gpu/drm/sti/sti_drv.c b/drivers/gpu/drm/sti/sti_drv.c
index 7cd3804c6dee..e6f0706bc6c7 100644
--- a/drivers/gpu/drm/sti/sti_drv.c
+++ b/drivers/gpu/drm/sti/sti_drv.c
@@ -140,7 +140,7 @@ err:
 	return ret;
 }
 
-void sti_drm_dbg_cleanup(struct drm_minor *minor)
+static void sti_drm_dbg_cleanup(struct drm_minor *minor)
 {
 	drm_debugfs_remove_files(sti_drm_dbg_list,
 				 ARRAY_SIZE(sti_drm_dbg_list), minor);
diff --git a/drivers/gpu/drm/sti/sti_dvo.c b/drivers/gpu/drm/sti/sti_dvo.c
index 00881eb4536e..e8c1ed08a9f7 100644
--- a/drivers/gpu/drm/sti/sti_dvo.c
+++ b/drivers/gpu/drm/sti/sti_dvo.c
@@ -17,6 +17,7 @@
 #include <drm/drm_panel.h>
 
 #include "sti_awg_utils.h"
+#include "sti_drv.h"
 #include "sti_mixer.h"
 
 /* DVO registers */
@@ -106,7 +107,7 @@ struct sti_dvo_connector {
 	container_of(x, struct sti_dvo_connector, drm_connector)
 
 #define BLANKING_LEVEL 16
-int dvo_awg_generate_code(struct sti_dvo *dvo, u8 *ram_size, u32 *ram_code)
+static int dvo_awg_generate_code(struct sti_dvo *dvo, u8 *ram_size, u32 *ram_code)
 {
 	struct drm_display_mode *mode = &dvo->mode;
 	struct dvo_config *config = dvo->config;
diff --git a/drivers/gpu/drm/sti/sti_gdp.c b/drivers/gpu/drm/sti/sti_gdp.c
index 3fc62c1ea9c2..27b617db4a38 100644
--- a/drivers/gpu/drm/sti/sti_gdp.c
+++ b/drivers/gpu/drm/sti/sti_gdp.c
@@ -473,8 +473,8 @@ static void sti_gdp_disable(struct sti_gdp *gdp)
  * RETURNS:
  * 0 on success.
  */
-int sti_gdp_field_cb(struct notifier_block *nb,
-		unsigned long event, void *data)
+static int sti_gdp_field_cb(struct notifier_block *nb,
+			    unsigned long event, void *data)
 {
 	struct sti_gdp *gdp = container_of(nb, struct sti_gdp, vtg_field_nb);
 
@@ -882,7 +882,7 @@ static int sti_gdp_late_register(struct drm_plane *drm_plane)
 	return gdp_debugfs_init(gdp, drm_plane->dev->primary);
 }
 
-struct drm_plane_funcs sti_gdp_plane_helpers_funcs = {
+static const struct drm_plane_funcs sti_gdp_plane_helpers_funcs = {
 	.update_plane = drm_atomic_helper_update_plane,
 	.disable_plane = drm_atomic_helper_disable_plane,
 	.destroy = sti_gdp_destroy,
diff --git a/drivers/gpu/drm/sti/sti_hqvdp.c b/drivers/gpu/drm/sti/sti_hqvdp.c
index b5ee783e3e7c..04546ebb75d7 100644
--- a/drivers/gpu/drm/sti/sti_hqvdp.c
+++ b/drivers/gpu/drm/sti/sti_hqvdp.c
@@ -17,6 +17,7 @@
 #include "sti_hqvdp_lut.h"
 #include "sti_plane.h"
 #include "sti_vtg.h"
+#include "sti_drv.h"
 
 /* Firmware name */
 #define HQVDP_FMW_NAME          "hqvdp-stih407.bin"
@@ -783,7 +784,7 @@ static void sti_hqvdp_disable(struct sti_hqvdp *hqvdp)
  * RETURNS:
  * 0 on success.
  */
-int sti_hqvdp_vtg_cb(struct notifier_block *nb, unsigned long evt, void *data)
+static int sti_hqvdp_vtg_cb(struct notifier_block *nb, unsigned long evt, void *data)
 {
 	struct sti_hqvdp *hqvdp = container_of(nb, struct sti_hqvdp, vtg_nb);
 	int btm_cmd_offset, top_cmd_offest;
@@ -1250,7 +1251,7 @@ static int sti_hqvdp_late_register(struct drm_plane *drm_plane)
 	return hqvdp_debugfs_init(hqvdp, drm_plane->dev->primary);
 }
 
-struct drm_plane_funcs sti_hqvdp_plane_helpers_funcs = {
+static const struct drm_plane_funcs sti_hqvdp_plane_helpers_funcs = {
 	.update_plane = drm_atomic_helper_update_plane,
 	.disable_plane = drm_atomic_helper_disable_plane,
 	.destroy = sti_hqvdp_destroy,
@@ -1289,7 +1290,7 @@ static struct drm_plane *sti_hqvdp_create(struct drm_device *drm_dev,
 	return &hqvdp->plane.drm_plane;
 }
 
-int sti_hqvdp_bind(struct device *dev, struct device *master, void *data)
+static int sti_hqvdp_bind(struct device *dev, struct device *master, void *data)
 {
 	struct sti_hqvdp *hqvdp = dev_get_drvdata(dev);
 	struct drm_device *drm_dev = data;
diff --git a/drivers/gpu/drm/sti/sti_mixer.c b/drivers/gpu/drm/sti/sti_mixer.c
index 7d9aea805eab..b78cec538aaa 100644
--- a/drivers/gpu/drm/sti/sti_mixer.c
+++ b/drivers/gpu/drm/sti/sti_mixer.c
@@ -358,7 +358,7 @@ int sti_mixer_set_plane_status(struct sti_mixer *mixer,
 	return 0;
 }
 
-void sti_mixer_set_matrix(struct sti_mixer *mixer)
+static void sti_mixer_set_matrix(struct sti_mixer *mixer)
 {
 	unsigned int i;
 
diff --git a/drivers/gpu/drm/sti/sti_tvout.c b/drivers/gpu/drm/sti/sti_tvout.c
index e25995b35715..cc07e069a770 100644
--- a/drivers/gpu/drm/sti/sti_tvout.c
+++ b/drivers/gpu/drm/sti/sti_tvout.c
@@ -18,6 +18,7 @@
 #include <drm/drm_crtc_helper.h>
 
 #include "sti_crtc.h"
+#include "sti_drv.h"
 #include "sti_vtg.h"
 
 /* glue registers */
diff --git a/drivers/gpu/drm/sti/sti_vtac.c b/drivers/gpu/drm/sti/sti_vtac.c
index b1eb0d77630d..cf7fe8a1db42 100644
--- a/drivers/gpu/drm/sti/sti_vtac.c
+++ b/drivers/gpu/drm/sti/sti_vtac.c
@@ -12,6 +12,8 @@
 
 #include <drm/drmP.h>
 
+#include "sti_drv.h"
+
 /* registers offset */
 #define VTAC_CONFIG                     0x00
 #define VTAC_RX_FIFO_CONFIG             0x04
diff --git a/drivers/gpu/drm/sti/sti_vtg.c b/drivers/gpu/drm/sti/sti_vtg.c
index 0bdc385eec17..a8882bdd0f8b 100644
--- a/drivers/gpu/drm/sti/sti_vtg.c
+++ b/drivers/gpu/drm/sti/sti_vtg.c
@@ -13,6 +13,7 @@
 
 #include <drm/drmP.h>
 
+#include "sti_drv.h"
 #include "sti_vtg.h"
 
 #define VTG_MODE_MASTER         0
@@ -72,7 +73,7 @@
 #define AWG_DELAY_ED        (-8)
 #define AWG_DELAY_SD        (-7)
 
-LIST_HEAD(vtg_lookup);
+static LIST_HEAD(vtg_lookup);
 
 /*
  * STI VTG register offset structure