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drm/bridge: Add connector-related bridge operations and data
To support implementation of DRM connectors on top of DRM bridges instead of by bridges, the drm_bridge needs to expose new operations and data: - Output detection, hot-plug notification, mode retrieval and EDID retrieval operations - Bitmask of supported operations - Bridge output type - I2C adapter for DDC access Add and document these. Three new bridge helper functions are also added to handle hot plug notification in a way that is as transparent as possible for the bridges. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org> Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com> Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200226112514.12455-8-laurent.pinchart@ideasonboard.com
This commit is contained in:
Laurent Pinchart
Tomi Valkeinen
parent
0451369bc5
commit
11f6c4b1b2
@ -95,6 +95,8 @@ static LIST_HEAD(bridge_list);
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*/
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void drm_bridge_add(struct drm_bridge *bridge)
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{
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mutex_init(&bridge->hpd_mutex);
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mutex_lock(&bridge_lock);
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list_add_tail(&bridge->list, &bridge_list);
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mutex_unlock(&bridge_lock);
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@ -111,6 +113,8 @@ void drm_bridge_remove(struct drm_bridge *bridge)
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mutex_lock(&bridge_lock);
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list_del_init(&bridge->list);
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mutex_unlock(&bridge_lock);
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mutex_destroy(&bridge->hpd_mutex);
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}
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EXPORT_SYMBOL(drm_bridge_remove);
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@ -241,7 +245,7 @@ void drm_bridge_detach(struct drm_bridge *bridge)
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* Bridge drivers expose operations through the &drm_bridge_funcs structure.
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* The DRM internals (atomic and CRTC helpers) use the helpers defined in
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* drm_bridge.c to call bridge operations. Those operations are divided in
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* two big categories to support different parts of the bridge usage.
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* three big categories to support different parts of the bridge usage.
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*
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* - The encoder-related operations support control of the bridges in the
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* chain, and are roughly counterparts to the &drm_encoder_helper_funcs
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@ -271,6 +275,43 @@ void drm_bridge_detach(struct drm_bridge *bridge)
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* implement them shall thus also implement the atomic version of the
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* encoder-related operations. This feature is not supported by the legacy
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* CRTC helpers.
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*
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* - The connector-related operations support implementing a &drm_connector
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* based on a chain of bridges. DRM bridges traditionally create a
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* &drm_connector for bridges meant to be used at the end of the chain. This
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* puts additional burden on bridge drivers, especially for bridges that may
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* be used in the middle of a chain or at the end of it. Furthermore, it
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* requires all operations of the &drm_connector to be handled by a single
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* bridge, which doesn't always match the hardware architecture.
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*
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* To simplify bridge drivers and make the connector implementation more
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* flexible, a new model allows bridges to unconditionally skip creation of
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* &drm_connector and instead expose &drm_bridge_funcs operations to support
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* an externally-implemented &drm_connector. Those operations are
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* &drm_bridge_funcs.detect, &drm_bridge_funcs.get_modes,
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* &drm_bridge_funcs.get_edid, &drm_bridge_funcs.hpd_notify,
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* &drm_bridge_funcs.hpd_enable and &drm_bridge_funcs.hpd_disable. When
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* implemented, display drivers shall create a &drm_connector instance for
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* each chain of bridges, and implement those connector instances based on
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* the bridge connector operations.
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*
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* Bridge drivers shall implement the connector-related operations for all
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* the features that the bridge hardware support. For instance, if a bridge
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* supports reading EDID, the &drm_bridge_funcs.get_edid shall be
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* implemented. This however doesn't mean that the DDC lines are wired to the
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* bridge on a particular platform, as they could also be connected to an I2C
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* controller of the SoC. Support for the connector-related operations on the
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* running platform is reported through the &drm_bridge.ops flags. Bridge
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* drivers shall detect which operations they can support on the platform
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* (usually this information is provided by ACPI or DT), and set the
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* &drm_bridge.ops flags for all supported operations. A flag shall only be
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* set if the corresponding &drm_bridge_funcs operation is implemented, but
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* an implemented operation doesn't necessarily imply that the corresponding
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* flag will be set. Display drivers shall use the &drm_bridge.ops flags to
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* decide which bridge to delegate a connector operation to. This mechanism
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* allows providing a single static const &drm_bridge_funcs instance in
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* bridge drivers, improving security by storing function pointers in
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* read-only memory.
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*/
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/**
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@ -970,6 +1011,164 @@ int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
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}
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EXPORT_SYMBOL(drm_atomic_bridge_chain_check);
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/**
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* drm_bridge_detect - check if anything is attached to the bridge output
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* @bridge: bridge control structure
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*
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* If the bridge supports output detection, as reported by the
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* DRM_BRIDGE_OP_DETECT bridge ops flag, call &drm_bridge_funcs.detect for the
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* bridge and return the connection status. Otherwise return
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* connector_status_unknown.
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*
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* RETURNS:
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* The detection status on success, or connector_status_unknown if the bridge
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* doesn't support output detection.
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*/
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enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge)
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{
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if (!(bridge->ops & DRM_BRIDGE_OP_DETECT))
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return connector_status_unknown;
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return bridge->funcs->detect(bridge);
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}
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EXPORT_SYMBOL_GPL(drm_bridge_detect);
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/**
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* drm_bridge_get_modes - fill all modes currently valid for the sink into the
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* @connector
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* @bridge: bridge control structure
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* @connector: the connector to fill with modes
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*
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* If the bridge supports output modes retrieval, as reported by the
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* DRM_BRIDGE_OP_MODES bridge ops flag, call &drm_bridge_funcs.get_modes to
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* fill the connector with all valid modes and return the number of modes
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* added. Otherwise return 0.
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*
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* RETURNS:
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* The number of modes added to the connector.
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*/
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int drm_bridge_get_modes(struct drm_bridge *bridge,
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struct drm_connector *connector)
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{
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if (!(bridge->ops & DRM_BRIDGE_OP_MODES))
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return 0;
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return bridge->funcs->get_modes(bridge, connector);
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}
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EXPORT_SYMBOL_GPL(drm_bridge_get_modes);
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/**
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* drm_bridge_get_edid - get the EDID data of the connected display
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* @bridge: bridge control structure
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* @connector: the connector to read EDID for
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*
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* If the bridge supports output EDID retrieval, as reported by the
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* DRM_BRIDGE_OP_EDID bridge ops flag, call &drm_bridge_funcs.get_edid to
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* get the EDID and return it. Otherwise return ERR_PTR(-ENOTSUPP).
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*
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* RETURNS:
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* The retrieved EDID on success, or an error pointer otherwise.
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*/
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struct edid *drm_bridge_get_edid(struct drm_bridge *bridge,
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struct drm_connector *connector)
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{
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if (!(bridge->ops & DRM_BRIDGE_OP_EDID))
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return ERR_PTR(-ENOTSUPP);
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return bridge->funcs->get_edid(bridge, connector);
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}
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EXPORT_SYMBOL_GPL(drm_bridge_get_edid);
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/**
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* drm_bridge_hpd_enable - enable hot plug detection for the bridge
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* @bridge: bridge control structure
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* @cb: hot-plug detection callback
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* @data: data to be passed to the hot-plug detection callback
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*
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* Call &drm_bridge_funcs.hpd_enable if implemented and register the given @cb
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* and @data as hot plug notification callback. From now on the @cb will be
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* called with @data when an output status change is detected by the bridge,
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* until hot plug notification gets disabled with drm_bridge_hpd_disable().
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*
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* Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in
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* bridge->ops. This function shall not be called when the flag is not set.
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*
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* Only one hot plug detection callback can be registered at a time, it is an
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* error to call this function when hot plug detection is already enabled for
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* the bridge.
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*/
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void drm_bridge_hpd_enable(struct drm_bridge *bridge,
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void (*cb)(void *data,
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enum drm_connector_status status),
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void *data)
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{
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if (!(bridge->ops & DRM_BRIDGE_OP_HPD))
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return;
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mutex_lock(&bridge->hpd_mutex);
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if (WARN(bridge->hpd_cb, "Hot plug detection already enabled\n"))
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goto unlock;
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bridge->hpd_cb = cb;
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bridge->hpd_data = data;
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if (bridge->funcs->hpd_enable)
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bridge->funcs->hpd_enable(bridge);
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unlock:
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mutex_unlock(&bridge->hpd_mutex);
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}
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EXPORT_SYMBOL_GPL(drm_bridge_hpd_enable);
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/**
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* drm_bridge_hpd_disable - disable hot plug detection for the bridge
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* @bridge: bridge control structure
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*
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* Call &drm_bridge_funcs.hpd_disable if implemented and unregister the hot
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* plug detection callback previously registered with drm_bridge_hpd_enable().
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* Once this function returns the callback will not be called by the bridge
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* when an output status change occurs.
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*
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* Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in
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* bridge->ops. This function shall not be called when the flag is not set.
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*/
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void drm_bridge_hpd_disable(struct drm_bridge *bridge)
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{
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if (!(bridge->ops & DRM_BRIDGE_OP_HPD))
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return;
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mutex_lock(&bridge->hpd_mutex);
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if (bridge->funcs->hpd_disable)
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bridge->funcs->hpd_disable(bridge);
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bridge->hpd_cb = NULL;
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bridge->hpd_data = NULL;
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mutex_unlock(&bridge->hpd_mutex);
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}
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EXPORT_SYMBOL_GPL(drm_bridge_hpd_disable);
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/**
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* drm_bridge_hpd_notify - notify hot plug detection events
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* @bridge: bridge control structure
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* @status: output connection status
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*
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* Bridge drivers shall call this function to report hot plug events when they
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* detect a change in the output status, when hot plug detection has been
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* enabled by drm_bridge_hpd_enable().
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*
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* This function shall be called in a context that can sleep.
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*/
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void drm_bridge_hpd_notify(struct drm_bridge *bridge,
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enum drm_connector_status status)
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{
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mutex_lock(&bridge->hpd_mutex);
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if (bridge->hpd_cb)
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bridge->hpd_cb(bridge->hpd_data, status);
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mutex_unlock(&bridge->hpd_mutex);
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}
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EXPORT_SYMBOL_GPL(drm_bridge_hpd_notify);
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#ifdef CONFIG_OF
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/**
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* of_drm_find_bridge - find the bridge corresponding to the device node in
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@ -23,8 +23,9 @@
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#ifndef __DRM_BRIDGE_H__
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#define __DRM_BRIDGE_H__
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#include <linux/list.h>
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#include <linux/ctype.h>
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#include <linux/list.h>
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#include <linux/mutex.h>
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#include <drm/drm_atomic.h>
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#include <drm/drm_encoder.h>
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@ -33,7 +34,10 @@
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struct drm_bridge;
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struct drm_bridge_timings;
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struct drm_connector;
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struct drm_panel;
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struct edid;
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struct i2c_adapter;
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/**
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* struct drm_bridge_funcs - drm_bridge control functions
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@ -497,6 +501,119 @@ struct drm_bridge_funcs {
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* giving the reason of the failure otherwise.
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*/
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struct drm_bridge_state *(*atomic_reset)(struct drm_bridge *bridge);
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/**
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* @detect:
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*
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* Check if anything is attached to the bridge output.
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*
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* This callback is optional, if not implemented the bridge will be
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* considered as always having a component attached to its output.
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* Bridges that implement this callback shall set the
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* DRM_BRIDGE_OP_DETECT flag in their &drm_bridge->ops.
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*
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* RETURNS:
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*
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* drm_connector_status indicating the bridge output status.
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*/
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enum drm_connector_status (*detect)(struct drm_bridge *bridge);
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/**
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* @get_modes:
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*
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* Fill all modes currently valid for the sink into the &drm_connector
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* with drm_mode_probed_add().
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*
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* The @get_modes callback is mostly intended to support non-probeable
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* displays such as many fixed panels. Bridges that support reading
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* EDID shall leave @get_modes unimplemented and implement the
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* &drm_bridge_funcs->get_edid callback instead.
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*
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* This callback is optional. Bridges that implement it shall set the
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* DRM_BRIDGE_OP_MODES flag in their &drm_bridge->ops.
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*
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* The connector parameter shall be used for the sole purpose of
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* filling modes, and shall not be stored internally by bridge drivers
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* for future usage.
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*
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* RETURNS:
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*
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* The number of modes added by calling drm_mode_probed_add().
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*/
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int (*get_modes)(struct drm_bridge *bridge,
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struct drm_connector *connector);
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/**
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* @get_edid:
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*
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* Read and parse the EDID data of the connected display.
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*
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* The @get_edid callback is the preferred way of reporting mode
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* information for a display connected to the bridge output. Bridges
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* that support reading EDID shall implement this callback and leave
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* the @get_modes callback unimplemented.
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*
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* The caller of this operation shall first verify the output
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* connection status and refrain from reading EDID from a disconnected
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* output.
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*
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* This callback is optional. Bridges that implement it shall set the
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* DRM_BRIDGE_OP_EDID flag in their &drm_bridge->ops.
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*
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* The connector parameter shall be used for the sole purpose of EDID
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* retrieval and parsing, and shall not be stored internally by bridge
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* drivers for future usage.
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*
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* RETURNS:
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*
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* An edid structure newly allocated with kmalloc() (or similar) on
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* success, or NULL otherwise. The caller is responsible for freeing
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* the returned edid structure with kfree().
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*/
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struct edid *(*get_edid)(struct drm_bridge *bridge,
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struct drm_connector *connector);
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/**
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* @hpd_notify:
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*
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* Notify the bridge of hot plug detection.
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*
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* This callback is optional, it may be implemented by bridges that
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* need to be notified of display connection or disconnection for
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* internal reasons. One use case is to reset the internal state of CEC
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* controllers for HDMI bridges.
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*/
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void (*hpd_notify)(struct drm_bridge *bridge,
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enum drm_connector_status status);
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/**
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* @hpd_enable:
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*
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* Enable hot plug detection. From now on the bridge shall call
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* drm_bridge_hpd_notify() each time a change is detected in the output
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* connection status, until hot plug detection gets disabled with
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* @hpd_disable.
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*
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* This callback is optional and shall only be implemented by bridges
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* that support hot-plug notification without polling. Bridges that
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* implement it shall also implement the @hpd_disable callback and set
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* the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
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*/
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void (*hpd_enable)(struct drm_bridge *bridge);
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/**
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* @hpd_disable:
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*
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* Disable hot plug detection. Once this function returns the bridge
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* shall not call drm_bridge_hpd_notify() when a change in the output
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* connection status occurs.
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*
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* This callback is optional and shall only be implemented by bridges
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* that support hot-plug notification without polling. Bridges that
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* implement it shall also implement the @hpd_enable callback and set
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* the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
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*/
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void (*hpd_disable)(struct drm_bridge *bridge);
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};
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/**
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@ -535,6 +652,39 @@ struct drm_bridge_timings {
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bool dual_link;
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};
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/**
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* enum drm_bridge_ops - Bitmask of operations supported by the bridge
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*/
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enum drm_bridge_ops {
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/**
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* @DRM_BRIDGE_OP_DETECT: The bridge can detect displays connected to
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* its output. Bridges that set this flag shall implement the
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* &drm_bridge_funcs->detect callback.
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*/
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DRM_BRIDGE_OP_DETECT = BIT(0),
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/**
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* @DRM_BRIDGE_OP_EDID: The bridge can retrieve the EDID of the display
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* connected to its output. Bridges that set this flag shall implement
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* the &drm_bridge_funcs->get_edid callback.
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*/
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DRM_BRIDGE_OP_EDID = BIT(1),
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/**
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* @DRM_BRIDGE_OP_HPD: The bridge can detect hot-plug and hot-unplug
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* without requiring polling. Bridges that set this flag shall
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* implement the &drm_bridge_funcs->hpd_enable and
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* &drm_bridge_funcs->hpd_disable callbacks if they support enabling
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* and disabling hot-plug detection dynamically.
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*/
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DRM_BRIDGE_OP_HPD = BIT(2),
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/**
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* @DRM_BRIDGE_OP_MODES: The bridge can retrieve the modes supported
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* by the display at its output. This does not include reading EDID
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* which is separately covered by @DRM_BRIDGE_OP_EDID. Bridges that set
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* this flag shall implement the &drm_bridge_funcs->get_modes callback.
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*/
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DRM_BRIDGE_OP_MODES = BIT(3),
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};
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/**
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* struct drm_bridge - central DRM bridge control structure
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*/
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@ -563,6 +713,33 @@ struct drm_bridge {
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const struct drm_bridge_funcs *funcs;
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/** @driver_private: pointer to the bridge driver's internal context */
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void *driver_private;
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/** @ops: bitmask of operations supported by the bridge */
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enum drm_bridge_ops ops;
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/**
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* @type: Type of the connection at the bridge output
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* (DRM_MODE_CONNECTOR_*). For bridges at the end of this chain this
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* identifies the type of connected display.
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*/
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int type;
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/**
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* @ddc: Associated I2C adapter for DDC access, if any.
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*/
|
||||
struct i2c_adapter *ddc;
|
||||
/** private: */
|
||||
/**
|
||||
* @hpd_mutex: Protects the @hpd_cb and @hpd_data fields.
|
||||
*/
|
||||
struct mutex hpd_mutex;
|
||||
/**
|
||||
* @hpd_cb: Hot plug detection callback, registered with
|
||||
* drm_bridge_hpd_enable().
|
||||
*/
|
||||
void (*hpd_cb)(void *data, enum drm_connector_status status);
|
||||
/**
|
||||
* @hpd_data: Private data passed to the Hot plug detection callback
|
||||
* @hpd_cb.
|
||||
*/
|
||||
void *hpd_data;
|
||||
};
|
||||
|
||||
static inline struct drm_bridge *
|
||||
@ -669,6 +846,19 @@ drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
|
||||
u32 output_fmt,
|
||||
unsigned int *num_input_fmts);
|
||||
|
||||
enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge);
|
||||
int drm_bridge_get_modes(struct drm_bridge *bridge,
|
||||
struct drm_connector *connector);
|
||||
struct edid *drm_bridge_get_edid(struct drm_bridge *bridge,
|
||||
struct drm_connector *connector);
|
||||
void drm_bridge_hpd_enable(struct drm_bridge *bridge,
|
||||
void (*cb)(void *data,
|
||||
enum drm_connector_status status),
|
||||
void *data);
|
||||
void drm_bridge_hpd_disable(struct drm_bridge *bridge);
|
||||
void drm_bridge_hpd_notify(struct drm_bridge *bridge,
|
||||
enum drm_connector_status status);
|
||||
|
||||
#ifdef CONFIG_DRM_PANEL_BRIDGE
|
||||
struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel);
|
||||
struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
|
||||
|
||||
Loading…
Reference in New Issue
Block a user