drm/atomic-helper: Add a TV properties reset helper

The drm_tv_create_properties() function will create a bunch of properties,
but it's up to each and every driver using that function to properly reset
the state of these properties leading to inconsistent behaviours.

Let's create a helper that will take care of it.

Reviewed-by: Noralf Trønnes <[e-mail]>
Tested-by: Mateusz Kwiatkowski <[e-mail]>
Acked-in-principle-or-something-like-that-by: Daniel Vetter <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Maxime Ripard <[e-mail]>

drivers/gpu/drm/drm_atomic_state_helper.c

···
 EXPORT_SYMBOL(drm_atomic_helper_connector_tv_margins_reset);
 
 /**
+ * drm_atomic_helper_connector_tv_reset - Resets Analog TV connector properties
+ * @connector: DRM connector
+ *
+ * Resets the analog TV properties attached to a connector
+ */
+void drm_atomic_helper_connector_tv_reset(struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+	struct drm_cmdline_mode *cmdline = &connector->cmdline_mode;
+	struct drm_connector_state *state = connector->state;
+	struct drm_property *prop;
+	uint64_t val;
+
+	prop = dev->mode_config.tv_mode_property;
+	if (prop)
+		if (!drm_object_property_get_default_value(&connector->base,
+							   prop, &val))
+			state->tv.mode = val;
+
+	if (cmdline->tv_mode_specified)
+		state->tv.mode = cmdline->tv_mode;
+
+	prop = dev->mode_config.tv_select_subconnector_property;
+	if (prop)
+		if (!drm_object_property_get_default_value(&connector->base,
+							   prop, &val))
+			state->tv.select_subconnector = val;
+
+	prop = dev->mode_config.tv_subconnector_property;
+	if (prop)
+		if (!drm_object_property_get_default_value(&connector->base,
+							   prop, &val))
+			state->tv.subconnector = val;
+
+	prop = dev->mode_config.tv_brightness_property;
+	if (prop)
+		if (!drm_object_property_get_default_value(&connector->base,
+							   prop, &val))
+			state->tv.brightness = val;
+
+	prop = dev->mode_config.tv_contrast_property;
+	if (prop)
+		if (!drm_object_property_get_default_value(&connector->base,
+							   prop, &val))
+			state->tv.contrast = val;
+
+	prop = dev->mode_config.tv_flicker_reduction_property;
+	if (prop)
+		if (!drm_object_property_get_default_value(&connector->base,
+							   prop, &val))
+			state->tv.flicker_reduction = val;
+
+	prop = dev->mode_config.tv_overscan_property;
+	if (prop)
+		if (!drm_object_property_get_default_value(&connector->base,
+							   prop, &val))
+			state->tv.overscan = val;
+
+	prop = dev->mode_config.tv_saturation_property;
+	if (prop)
+		if (!drm_object_property_get_default_value(&connector->base,
+							   prop, &val))
+			state->tv.saturation = val;
+
+	prop = dev->mode_config.tv_hue_property;
+	if (prop)
+		if (!drm_object_property_get_default_value(&connector->base,
+							   prop, &val))
+			state->tv.hue = val;
+
+	drm_atomic_helper_connector_tv_margins_reset(connector);
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_tv_reset);
+
+/**
  * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state
  * @connector: connector object
  * @state: atomic connector state

include/drm/drm_atomic_state_helper.h

···
 void __drm_atomic_helper_connector_reset(struct drm_connector *connector,
 					 struct drm_connector_state *conn_state);
 void drm_atomic_helper_connector_reset(struct drm_connector *connector);
+void drm_atomic_helper_connector_tv_reset(struct drm_connector *connector);
 void drm_atomic_helper_connector_tv_margins_reset(struct drm_connector *connector);
 void
 __drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,