drm/vc4: hdmi: Constify drm_display_mode

We don't modify the drm_display_mode pointer we have in the driver in
most places, so let's make them const.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220829134731.213478-2-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -335,7 +335,7 @@ static int vc4_hdmi_connector_get_modes(struct drm_connector *connector)
 
 	if (vc4_hdmi->disable_4kp60) {
 		struct drm_device *drm = connector->dev;
-		struct drm_display_mode *mode;
+		const struct drm_display_mode *mode;
 
 		list_for_each_entry(mode, &connector->probed_modes, head) {
 			if (vc4_hdmi_mode_needs_scrambling(mode, 8, VC4_HDMI_OUTPUT_RGB)) {
@@ -709,7 +709,7 @@ static void vc4_hdmi_set_infoframes(struct drm_encoder *encoder)
 }
 
 static bool vc4_hdmi_supports_scrambling(struct drm_encoder *encoder,
-					 struct drm_display_mode *mode)
+					 const struct drm_display_mode *mode)
 {
 	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
 	struct drm_display_info *display = &vc4_hdmi->connector.display_info;
@@ -732,7 +732,7 @@ static void vc4_hdmi_enable_scrambling(struct drm_encoder *encoder)
 {
 	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
 	struct drm_device *drm = vc4_hdmi->connector.dev;
-	struct drm_display_mode *mode = &vc4_hdmi->saved_adjusted_mode;
+	const struct drm_display_mode *mode = &vc4_hdmi->saved_adjusted_mode;
 	unsigned long flags;
 	int idx;
 
@@ -1077,7 +1077,7 @@ static void vc5_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi,
 
 static void vc4_hdmi_set_timings(struct vc4_hdmi *vc4_hdmi,
 				 struct drm_connector_state *state,
-				 struct drm_display_mode *mode)
+				 const struct drm_display_mode *mode)
 {
 	struct drm_device *drm = vc4_hdmi->connector.dev;
 	bool hsync_pos = mode->flags & DRM_MODE_FLAG_PHSYNC;
@@ -1141,7 +1141,7 @@ static void vc4_hdmi_set_timings(struct vc4_hdmi *vc4_hdmi,
 
 static void vc5_hdmi_set_timings(struct vc4_hdmi *vc4_hdmi,
 				 struct drm_connector_state *state,
-				 struct drm_display_mode *mode)
+				 const struct drm_display_mode *mode)
 {
 	struct drm_device *drm = vc4_hdmi->connector.dev;
 	const struct vc4_hdmi_connector_state *vc4_state =
@@ -1303,7 +1303,7 @@ static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
 		drm_atomic_get_new_connector_state(state, connector);
 	struct vc4_hdmi_connector_state *vc4_conn_state =
 		conn_state_to_vc4_hdmi_conn_state(conn_state);
-	struct drm_display_mode *mode = &vc4_hdmi->saved_adjusted_mode;
+	const struct drm_display_mode *mode = &vc4_hdmi->saved_adjusted_mode;
 	unsigned long tmds_char_rate = vc4_conn_state->tmds_char_rate;
 	unsigned long bvb_rate, hsm_rate;
 	unsigned long flags;
@@ -1416,7 +1416,7 @@ static void vc4_hdmi_encoder_pre_crtc_enable(struct drm_encoder *encoder,
 	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
 	struct drm_device *drm = vc4_hdmi->connector.dev;
 	struct drm_connector *connector = &vc4_hdmi->connector;
-	struct drm_display_mode *mode = &vc4_hdmi->saved_adjusted_mode;
+	const struct drm_display_mode *mode = &vc4_hdmi->saved_adjusted_mode;
 	struct drm_connector_state *conn_state =
 		drm_atomic_get_new_connector_state(state, connector);
 	unsigned long flags;
@@ -1445,7 +1445,7 @@ static void vc4_hdmi_encoder_post_crtc_enable(struct drm_encoder *encoder,
 {
 	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
 	struct drm_device *drm = vc4_hdmi->connector.dev;
-	struct drm_display_mode *mode = &vc4_hdmi->saved_adjusted_mode;
+	const struct drm_display_mode *mode = &vc4_hdmi->saved_adjusted_mode;
 	struct drm_display_info *display = &vc4_hdmi->connector.display_info;
 	bool hsync_pos = mode->flags & DRM_MODE_FLAG_PHSYNC;
 	bool vsync_pos = mode->flags & DRM_MODE_FLAG_PVSYNC;

drivers/gpu/drm/vc4/vc4_hdmi.h

@@ -72,7 +72,7 @@ struct vc4_hdmi_variant {
 	/* Callback to configure the video timings in the HDMI block */
 	void (*set_timings)(struct vc4_hdmi *vc4_hdmi,
 			    struct drm_connector_state *state,
-			    struct drm_display_mode *mode);
+			    const struct drm_display_mode *mode);
 
 	/* Callback to initialize the PHY according to the connector state */
 	void (*phy_init)(struct vc4_hdmi *vc4_hdmi,