diff options
Diffstat (limited to 'drivers/gpu/drm/drm_connector.c')
| -rw-r--r-- | drivers/gpu/drm/drm_connector.c | 180 |
1 files changed, 177 insertions, 3 deletions
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c index 4943cef178be..da8ae80c2750 100644 --- a/drivers/gpu/drm/drm_connector.c +++ b/drivers/gpu/drm/drm_connector.c @@ -260,9 +260,7 @@ int drm_connector_init(struct drm_device *dev, if (connector_type != DRM_MODE_CONNECTOR_VIRTUAL && connector_type != DRM_MODE_CONNECTOR_WRITEBACK) - drm_object_attach_property(&connector->base, - config->edid_property, - 0); + drm_connector_attach_edid_property(connector); drm_object_attach_property(&connector->base, config->dpms_property, 0); @@ -295,6 +293,24 @@ out_put: EXPORT_SYMBOL(drm_connector_init); /** + * drm_connector_attach_edid_property - attach edid property. + * @connector: the connector + * + * Some connector types like DRM_MODE_CONNECTOR_VIRTUAL do not get a + * edid property attached by default. This function can be used to + * explicitly enable the edid property in these cases. + */ +void drm_connector_attach_edid_property(struct drm_connector *connector) +{ + struct drm_mode_config *config = &connector->dev->mode_config; + + drm_object_attach_property(&connector->base, + config->edid_property, + 0); +} +EXPORT_SYMBOL(drm_connector_attach_edid_property); + +/** * drm_connector_attach_encoder - attach a connector to an encoder * @connector: connector to attach * @encoder: encoder to attach @connector to @@ -916,6 +932,13 @@ DRM_ENUM_NAME_FN(drm_get_content_protection_name, drm_cp_enum_list) * is no longer protected and userspace should take appropriate action * (whatever that might be). * + * max bpc: + * This range property is used by userspace to limit the bit depth. When + * used the driver would limit the bpc in accordance with the valid range + * supported by the hardware and sink. Drivers to use the function + * drm_connector_attach_max_bpc_property() to create and attach the + * property to the connector during initialization. + * * Connectors also have one standardized atomic property: * * CRTC_ID: @@ -1256,6 +1279,105 @@ int drm_mode_create_scaling_mode_property(struct drm_device *dev) EXPORT_SYMBOL(drm_mode_create_scaling_mode_property); /** + * DOC: Variable refresh properties + * + * Variable refresh rate capable displays can dynamically adjust their + * refresh rate by extending the duration of their vertical front porch + * until page flip or timeout occurs. This can reduce or remove stuttering + * and latency in scenarios where the page flip does not align with the + * vblank interval. + * + * An example scenario would be an application flipping at a constant rate + * of 48Hz on a 60Hz display. The page flip will frequently miss the vblank + * interval and the same contents will be displayed twice. This can be + * observed as stuttering for content with motion. + * + * If variable refresh rate was active on a display that supported a + * variable refresh range from 35Hz to 60Hz no stuttering would be observable + * for the example scenario. The minimum supported variable refresh rate of + * 35Hz is below the page flip frequency and the vertical front porch can + * be extended until the page flip occurs. The vblank interval will be + * directly aligned to the page flip rate. + * + * Not all userspace content is suitable for use with variable refresh rate. + * Large and frequent changes in vertical front porch duration may worsen + * perceived stuttering for input sensitive applications. + * + * Panel brightness will also vary with vertical front porch duration. Some + * panels may have noticeable differences in brightness between the minimum + * vertical front porch duration and the maximum vertical front porch duration. + * Large and frequent changes in vertical front porch duration may produce + * observable flickering for such panels. + * + * Userspace control for variable refresh rate is supported via properties + * on the &drm_connector and &drm_crtc objects. + * + * "vrr_capable": + * Optional &drm_connector boolean property that drivers should attach + * with drm_connector_attach_vrr_capable_property() on connectors that + * could support variable refresh rates. Drivers should update the + * property value by calling drm_connector_set_vrr_capable_property(). + * + * Absence of the property should indicate absence of support. + * + * "vrr_enabled": + * Default &drm_crtc boolean property that notifies the driver that the + * content on the CRTC is suitable for variable refresh rate presentation. + * The driver will take this property as a hint to enable variable + * refresh rate support if the receiver supports it, ie. if the + * "vrr_capable" property is true on the &drm_connector object. The + * vertical front porch duration will be extended until page-flip or + * timeout when enabled. + * + * The minimum vertical front porch duration is defined as the vertical + * front porch duration for the current mode. + * + * The maximum vertical front porch duration is greater than or equal to + * the minimum vertical front porch duration. The duration is derived + * from the minimum supported variable refresh rate for the connector. + * + * The driver may place further restrictions within these minimum + * and maximum bounds. + * + * The semantics for the vertical blank timestamp differ when + * variable refresh rate is active. The vertical blank timestamp + * is defined to be an estimate using the current mode's fixed + * refresh rate timings. The semantics for the page-flip event + * timestamp remain the same. + */ + +/** + * drm_connector_attach_vrr_capable_property - creates the + * vrr_capable property + * @connector: connector to create the vrr_capable property on. + * + * This is used by atomic drivers to add support for querying + * variable refresh rate capability for a connector. + * + * Returns: + * Zero on success, negative errono on failure. + */ +int drm_connector_attach_vrr_capable_property( + struct drm_connector *connector) +{ + struct drm_device *dev = connector->dev; + struct drm_property *prop; + + if (!connector->vrr_capable_property) { + prop = drm_property_create_bool(dev, DRM_MODE_PROP_IMMUTABLE, + "vrr_capable"); + if (!prop) + return -ENOMEM; + + connector->vrr_capable_property = prop; + drm_object_attach_property(&connector->base, prop, 0); + } + + return 0; +} +EXPORT_SYMBOL(drm_connector_attach_vrr_capable_property); + +/** * drm_connector_attach_scaling_mode_property - attach atomic scaling mode property * @connector: connector to attach scaling mode property on. * @scaling_mode_mask: or'ed mask of BIT(%DRM_MODE_SCALE_\*). @@ -1584,6 +1706,58 @@ void drm_connector_set_link_status_property(struct drm_connector *connector, EXPORT_SYMBOL(drm_connector_set_link_status_property); /** + * drm_connector_attach_max_bpc_property - attach "max bpc" property + * @connector: connector to attach max bpc property on. + * @min: The minimum bit depth supported by the connector. + * @max: The maximum bit depth supported by the connector. + * + * This is used to add support for limiting the bit depth on a connector. + * + * Returns: + * Zero on success, negative errno on failure. + */ +int drm_connector_attach_max_bpc_property(struct drm_connector *connector, + int min, int max) +{ + struct drm_device *dev = connector->dev; + struct drm_property *prop; + + prop = connector->max_bpc_property; + if (!prop) { + prop = drm_property_create_range(dev, 0, "max bpc", min, max); + if (!prop) + return -ENOMEM; + + connector->max_bpc_property = prop; + } + + drm_object_attach_property(&connector->base, prop, max); + connector->state->max_requested_bpc = max; + connector->state->max_bpc = max; + + return 0; +} +EXPORT_SYMBOL(drm_connector_attach_max_bpc_property); + +/** + * drm_connector_set_vrr_capable_property - sets the variable refresh rate + * capable property for a connector + * @connector: drm connector + * @capable: True if the connector is variable refresh rate capable + * + * Should be used by atomic drivers to update the indicated support for + * variable refresh rate over a connector. + */ +void drm_connector_set_vrr_capable_property( + struct drm_connector *connector, bool capable) +{ + drm_object_property_set_value(&connector->base, + connector->vrr_capable_property, + capable); +} +EXPORT_SYMBOL(drm_connector_set_vrr_capable_property); + +/** * drm_connector_init_panel_orientation_property - * initialize the connecters panel_orientation property * @connector: connector for which to init the panel-orientation property. |