drm: make mode_valid callback optional

Many drm connectors do not need mode validation.
The patch makes this callback optional and removes dumb implementations.

v2: Rebase:
- imx move to a shared (but still dummy) ->mode_valid implementation.
- probe helpers have been extracted to drm_probe_helper.c

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Documentation/DocBook/drm.tmpl

@@ -1903,8 +1903,8 @@ void intel_crt_init(struct drm_device *dev)
           <para>
             The function filters out modes larger than
             <parameter>max_width</parameter> and <parameter>max_height</parameter>
-            if specified. It then calls the connector
-            <methodname>mode_valid</methodname> helper operation for  each mode in
+            if specified. It then calls the optional connector
+            <methodname>mode_valid</methodname> helper operation for each mode in
             the probed list to check whether the mode is valid for the connector.
           </para>
         </listitem>
@@ -2265,7 +2265,7 @@ void intel_crt_init(struct drm_device *dev)
           <para>
             Verify whether a mode is valid for the connector. Return MODE_OK for
             supported modes and one of the enum drm_mode_status values (MODE_*)
-            for unsupported modes. This operation is mandatory.
+            for unsupported modes. This operation is optional.
           </para>
           <para>
             As the mode rejection reason is currently not used beside for

drivers/gpu/drm/ast/ast_mode.c

@@ -743,12 +743,6 @@ static int ast_get_modes(struct drm_connector *connector)
 	return 0;
 }
 
-static int ast_mode_valid(struct drm_connector *connector,
-			  struct drm_display_mode *mode)
-{
-	return MODE_OK;
-}
-
 static void ast_connector_destroy(struct drm_connector *connector)
 {
 	struct ast_connector *ast_connector = to_ast_connector(connector);
@@ -765,7 +759,6 @@ ast_connector_detect(struct drm_connector *connector, bool force)
 }
 
 static const struct drm_connector_helper_funcs ast_connector_helper_funcs = {
-	.mode_valid = ast_mode_valid,
 	.get_modes = ast_get_modes,
 	.best_encoder = ast_best_single_encoder,
 };

drivers/gpu/drm/bridge/ptn3460.c

@@ -225,12 +225,6 @@ int ptn3460_get_modes(struct drm_connector *connector)
 	return num_modes;
 }
 
-static int ptn3460_mode_valid(struct drm_connector *connector,
-		struct drm_display_mode *mode)
-{
-	return MODE_OK;
-}
-
 struct drm_encoder *ptn3460_best_encoder(struct drm_connector *connector)
 {
 	struct ptn3460_bridge *ptn_bridge;
@@ -242,7 +236,6 @@ struct drm_encoder *ptn3460_best_encoder(struct drm_connector *connector)
 
 struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {
 	.get_modes = ptn3460_get_modes,
-	.mode_valid = ptn3460_mode_valid,
 	.best_encoder = ptn3460_best_encoder,
 };
 

drivers/gpu/drm/cirrus/cirrus_mode.c

@@ -505,13 +505,6 @@ static int cirrus_vga_get_modes(struct drm_connector *connector)
 	return count;
 }
 
-static int cirrus_vga_mode_valid(struct drm_connector *connector,
-				 struct drm_display_mode *mode)
-{
-	/* Any mode we've added is valid */
-	return MODE_OK;
-}
-
 static struct drm_encoder *cirrus_connector_best_encoder(struct drm_connector
 						  *connector)
 {
@@ -546,7 +539,6 @@ static void cirrus_connector_destroy(struct drm_connector *connector)
 
 struct drm_connector_helper_funcs cirrus_vga_connector_helper_funcs = {
 	.get_modes = cirrus_vga_get_modes,
-	.mode_valid = cirrus_vga_mode_valid,
 	.best_encoder = cirrus_connector_best_encoder,
 };
 

drivers/gpu/drm/drm_probe_helper.c

@@ -169,7 +169,7 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
 	drm_mode_validate_flag(connector, mode_flags);
 
 	list_for_each_entry(mode, &connector->modes, head) {
-		if (mode->status == MODE_OK)
+		if (mode->status == MODE_OK && connector_funcs->mode_valid)
 			mode->status = connector_funcs->mode_valid(connector,
 								   mode);
 	}

drivers/gpu/drm/exynos/exynos_dp_core.c

@@ -949,12 +949,6 @@ static int exynos_dp_get_modes(struct drm_connector *connector)
 	return 1;
 }
 
-static int exynos_dp_mode_valid(struct drm_connector *connector,
-			struct drm_display_mode *mode)
-{
-	return MODE_OK;
-}
-
 static struct drm_encoder *exynos_dp_best_encoder(
 			struct drm_connector *connector)
 {
@@ -965,7 +959,6 @@ static struct drm_encoder *exynos_dp_best_encoder(
 
 static struct drm_connector_helper_funcs exynos_dp_connector_helper_funcs = {
 	.get_modes = exynos_dp_get_modes,
-	.mode_valid = exynos_dp_mode_valid,
 	.best_encoder = exynos_dp_best_encoder,
 };
 

drivers/gpu/drm/exynos/exynos_drm_dpi.c

@@ -94,12 +94,6 @@ static int exynos_dpi_get_modes(struct drm_connector *connector)
 	return 0;
 }
 
-static int exynos_dpi_mode_valid(struct drm_connector *connector,
-				 struct drm_display_mode *mode)
-{
-	return MODE_OK;
-}
-
 static struct drm_encoder *
 exynos_dpi_best_encoder(struct drm_connector *connector)
 {
@@ -110,7 +104,6 @@ exynos_dpi_best_encoder(struct drm_connector *connector)
 
 static struct drm_connector_helper_funcs exynos_dpi_connector_helper_funcs = {
 	.get_modes = exynos_dpi_get_modes,
-	.mode_valid = exynos_dpi_mode_valid,
 	.best_encoder = exynos_dpi_best_encoder,
 };
 

drivers/gpu/drm/exynos/exynos_drm_vidi.c

@@ -533,12 +533,6 @@ static int vidi_get_modes(struct drm_connector *connector)
 	return drm_add_edid_modes(connector, edid);
 }
 
-static int vidi_mode_valid(struct drm_connector *connector,
-			struct drm_display_mode *mode)
-{
-	return MODE_OK;
-}
-
 static struct drm_encoder *vidi_best_encoder(struct drm_connector *connector)
 {
 	struct vidi_context *ctx = ctx_from_connector(connector);
@@ -548,7 +542,6 @@ static struct drm_encoder *vidi_best_encoder(struct drm_connector *connector)
 
 static struct drm_connector_helper_funcs vidi_connector_helper_funcs = {
 	.get_modes = vidi_get_modes,
-	.mode_valid = vidi_mode_valid,
 	.best_encoder = vidi_best_encoder,
 };
 

drivers/gpu/drm/rcar-du/rcar_du_lvdscon.c

@@ -57,15 +57,8 @@ static int rcar_du_lvds_connector_get_modes(struct drm_connector *connector)
 	return 1;
 }
 
-static int rcar_du_lvds_connector_mode_valid(struct drm_connector *connector,
-					    struct drm_display_mode *mode)
-{
-	return MODE_OK;
-}
-
 static const struct drm_connector_helper_funcs connector_helper_funcs = {
 	.get_modes = rcar_du_lvds_connector_get_modes,
-	.mode_valid = rcar_du_lvds_connector_mode_valid,
 	.best_encoder = rcar_du_connector_best_encoder,
 };
 

drivers/gpu/drm/rcar-du/rcar_du_vgacon.c

@@ -25,15 +25,8 @@ static int rcar_du_vga_connector_get_modes(struct drm_connector *connector)
 	return 0;
 }
 
-static int rcar_du_vga_connector_mode_valid(struct drm_connector *connector,
-					    struct drm_display_mode *mode)
-{
-	return MODE_OK;
-}
-
 static const struct drm_connector_helper_funcs connector_helper_funcs = {
 	.get_modes = rcar_du_vga_connector_get_modes,
-	.mode_valid = rcar_du_vga_connector_mode_valid,
 	.best_encoder = rcar_du_connector_best_encoder,
 };
 

drivers/gpu/drm/shmobile/shmob_drm_crtc.c

@@ -674,12 +674,6 @@ static int shmob_drm_connector_get_modes(struct drm_connector *connector)
 	return 1;
 }
 
-static int shmob_drm_connector_mode_valid(struct drm_connector *connector,
-					  struct drm_display_mode *mode)
-{
-	return MODE_OK;
-}
-
 static struct drm_encoder *
 shmob_drm_connector_best_encoder(struct drm_connector *connector)
 {
@@ -690,7 +684,6 @@ shmob_drm_connector_best_encoder(struct drm_connector *connector)
 
 static const struct drm_connector_helper_funcs connector_helper_funcs = {
 	.get_modes = shmob_drm_connector_get_modes,
-	.mode_valid = shmob_drm_connector_mode_valid,
 	.best_encoder = shmob_drm_connector_best_encoder,
 };
 

drivers/staging/imx-drm/imx-drm-core.c

@@ -200,13 +200,6 @@ static const struct file_operations imx_drm_driver_fops = {
 	.llseek = noop_llseek,
 };
 
-int imx_drm_connector_mode_valid(struct drm_connector *connector,
-	struct drm_display_mode *mode)
-{
-	return MODE_OK;
-}
-EXPORT_SYMBOL(imx_drm_connector_mode_valid);
-
 void imx_drm_connector_destroy(struct drm_connector *connector)
 {
 	drm_sysfs_connector_remove(connector);

drivers/staging/imx-drm/imx-drm.h

@@ -50,8 +50,6 @@ int imx_drm_encoder_get_mux_id(struct device_node *node,
 int imx_drm_encoder_parse_of(struct drm_device *drm,
 	struct drm_encoder *encoder, struct device_node *np);
 
-int imx_drm_connector_mode_valid(struct drm_connector *connector,
-	struct drm_display_mode *mode);
 void imx_drm_connector_destroy(struct drm_connector *connector);
 void imx_drm_encoder_destroy(struct drm_encoder *encoder);
 

drivers/staging/imx-drm/imx-hdmi.c

@@ -1492,7 +1492,6 @@ static struct drm_connector_funcs imx_hdmi_connector_funcs = {
 
 static struct drm_connector_helper_funcs imx_hdmi_connector_helper_funcs = {
 	.get_modes = imx_hdmi_connector_get_modes,
-	.mode_valid = imx_drm_connector_mode_valid,
 	.best_encoder = imx_hdmi_connector_best_encoder,
 };
 

drivers/staging/imx-drm/imx-ldb.c

@@ -317,7 +317,6 @@ static struct drm_connector_funcs imx_ldb_connector_funcs = {
 static struct drm_connector_helper_funcs imx_ldb_connector_helper_funcs = {
 	.get_modes = imx_ldb_connector_get_modes,
 	.best_encoder = imx_ldb_connector_best_encoder,
-	.mode_valid = imx_drm_connector_mode_valid,
 };
 
 static struct drm_encoder_funcs imx_ldb_encoder_funcs = {

drivers/staging/imx-drm/imx-tve.c

@@ -251,10 +251,6 @@ static int imx_tve_connector_mode_valid(struct drm_connector *connector,
 	unsigned long rate;
 	int ret;
 
-	ret = imx_drm_connector_mode_valid(connector, mode);
-	if (ret != MODE_OK)
-		return ret;
-
 	/* pixel clock with 2x oversampling */
 	rate = clk_round_rate(tve->clk, 2000UL * mode->clock) / 2000;
 	if (rate == mode->clock)

drivers/staging/imx-drm/parallel-display.c

@@ -148,7 +148,6 @@ static struct drm_connector_funcs imx_pd_connector_funcs = {
 static struct drm_connector_helper_funcs imx_pd_connector_helper_funcs = {
 	.get_modes = imx_pd_connector_get_modes,
 	.best_encoder = imx_pd_connector_best_encoder,
-	.mode_valid = imx_drm_connector_mode_valid,
 };
 
 static struct drm_encoder_funcs imx_pd_encoder_funcs = {

include/drm/drm_crtc_helper.h

@@ -114,7 +114,7 @@ struct drm_encoder_helper_funcs {
 /**
  * drm_connector_helper_funcs - helper operations for connectors
  * @get_modes: get mode list for this connector
- * @mode_valid: is this mode valid on the given connector?
+ * @mode_valid (optional): is this mode valid on the given connector?
  *
  * The helper operations are called by the mid-layer CRTC helper.
  */