DOC: overview
In DRM connectors are the general abstraction for display sinks, and include
als fixed panels or anything else that can display pixels in some form. As
opposed to all other KMS objects representing hardware (like CRTC, encoder or
plane abstractions) connectors can be hotplugged and unplugged at runtime.
KMS driver must create, initialize, register and attach at a &struct
drm_connector for each such sink. The instance is created as other KMS
objects and initialized by setting the following fields. The connector is
initialized with a call to drm_connector_init() with a pointer to the
&struct drm_connector_funcs and a connector type, and then exposed to
userspace with a call to drm_connector_register().
Connectors must be attached to an encoder to be used. For devices that map
connectors to encoders 1:1, the connector should be attached at
initialization time with a call to drm_mode_connector_attach_encoder(). The
driver must also set the &drm_connector.encoder field to point to the
attached encoder.
For connectors which are not fixed (like built-in panels) the driver needs to
support hotplug notifications. The simplest way to do that is by using the
probe helpers, see drm_kms_helper_poll_init() for connectors which don't have
hardware support for hotplug interrupts. Connectors with hardware hotplug
support can instead use e.g. drm_helper_hpd_irq_event().
4.4的內核，結構體是放在crtc.h裏面的。最新的5.1kernel已經有drm_connector.h頭文件。
Each connector may be connected to one or more CRTCs, or may be clonable by another connector if they can share a CRTC. Each connector also has a specific position in the broader display (referred to as a 'screen' though it could
span multiple monitors).
dpms可以認爲是一個顯示能源管理系統，一般用於計算機功耗的管理。
struct drm_connector_funcs {
/**
* @dpms:
*
* Legacy entry point to set the per-connector DPMS state. Legacy DPMS
* is exposed as a standard property on the connector, but diverted to
* this callback in the drm core. Note that atomic drivers don't
* implement the 4 level DPMS support on the connector any more, but
* instead only have an on/off "ACTIVE" property on the CRTC object.
*
* This hook is not used by atomic drivers, remapping of the legacy DPMS
* property is entirely handled in the DRM core.
*
* RETURNS:
*
* 0 on success or a negative error code on failure.
*/
int (*dpms)(struct drm_connector *connector, int mode);
/**
* @reset:
*
* Reset connector hardware and software state to off. This function isn't
* called by the core directly, only through drm_mode_config_reset().
* It's not a helper hook only for historical reasons.
*
* Atomic drivers can use drm_atomic_helper_connector_reset() to reset
* atomic state using this hook.
*/
void (*reset)(struct drm_connector *connector);
/**
* @detect:
*
* Check to see if anything is attached to the connector. The parameter
* force is set to false whilst polling, true when checking the
* connector due to a user request. force can be used by the driver to
* avoid expensive, destructive operations during automated probing.
*
* This callback is optional, if not implemented the connector will be
* considered as always being attached.
*
* FIXME:
*
* Note that this hook is only called by the probe helper. It's not in
* the helper library vtable purely for historical reasons. The only DRM
* core entry point to probe connector state is @fill_modes.
*
* Note that the helper library will already hold
* &drm_mode_config.connection_mutex. Drivers which need to grab additional
* locks to avoid races with concurrent modeset changes need to use
* &drm_connector_helper_funcs.detect_ctx instead.
*
* RETURNS:
*
* drm_connector_status indicating the connector's status.
*/
enum drm_connector_status (*detect)(struct drm_connector *connector,
bool force);
/**
* @force:
*
* This function is called to update internal encoder state when the
* connector is forced to a certain state by userspace, either through
* the sysfs interfaces or on the kernel cmdline. In that case the
* @detect callback isn't called.
*
* FIXME:
*
* Note that this hook is only called by the probe helper. It's not in
* the helper library vtable purely for historical reasons. The only DRM
* core entry point to probe connector state is @fill_modes.
*/
void (*force)(struct drm_connector *connector);
/**
* @fill_modes:
*
* Entry point for output detection and basic mode validation. The
* driver should reprobe the output if needed (e.g. when hotplug
* handling is unreliable), add all detected modes to &drm_connector.modes
* and filter out any the device can't support in any configuration. It
* also needs to filter out any modes wider or higher than the
* parameters max_width and max_height indicate.
*
* The drivers must also prune any modes no longer valid from
* &drm_connector.modes. Furthermore it must update
* &drm_connector.status and &drm_connector.edid. If no EDID has been
* received for this output connector->edid must be NULL.
*
* Drivers using the probe helpers should use
* drm_helper_probe_single_connector_modes() to implement this
* function.
*
* RETURNS:
*
* The number of modes detected and filled into &drm_connector.modes.
*/
int (*fill_modes)(struct drm_connector *connector, uint32_t max_width, uint32_t max_height);
/**
* @set_property:
*
* This is the legacy entry point to update a property attached to the
* connector.
*
* This callback is optional if the driver does not support any legacy
* driver-private properties. For atomic drivers it is not used because
* property handling is done entirely in the DRM core.
*
* RETURNS:
*
* 0 on success or a negative error code on failure.
*/
int (*set_property)(struct drm_connector *connector, struct drm_property *property,
uint64_t val);
/**
* @late_register:
*
* This optional hook can be used to register additional userspace
* interfaces attached to the connector, light backlight control, i2c,
* DP aux or similar interfaces. It is called late in the driver load
* sequence from drm_connector_register() when registering all the
* core drm connector interfaces. Everything added from this callback
* should be unregistered in the early_unregister callback.
*
* This is called while holding &drm_connector.mutex.
*
* Returns:
*
* 0 on success, or a negative error code on failure.
*/
int (*late_register)(struct drm_connector *connector);
/**
* @early_unregister:
*
* This optional hook should be used to unregister the additional
* userspace interfaces attached to the connector from
* late_register(). It is called from drm_connector_unregister(),
* early in the driver unload sequence to disable userspace access
* before data structures are torndown.
*
* This is called while holding &drm_connector.mutex.
*/
void (*early_unregister)(struct drm_connector *connector);
/**
* @destroy:
*
* Clean up connector resources. This is called at driver unload time
* through drm_mode_config_cleanup(). It can also be called at runtime
* when a connector is being hot-unplugged for drivers that support
* connector hotplugging (e.g. DisplayPort MST).
*/
void (*destroy)(struct drm_connector *connector);
/**
* @atomic_duplicate_state:
*
* Duplicate the current atomic state for this connector and return it.
* The core and helpers guarantee that any atomic state duplicated with
* this hook and still owned by the caller (i.e. not transferred to the
* driver by calling &drm_mode_config_funcs.atomic_commit) will be
* cleaned up by calling the @atomic_destroy_state hook in this
* structure.
*
* This callback is mandatory for atomic drivers.
*
* Atomic drivers which don't subclass &struct drm_connector_state should use
* drm_atomic_helper_connector_duplicate_state(). Drivers that subclass the
* state structure to extend it with driver-private state should use
* __drm_atomic_helper_connector_duplicate_state() to make sure shared state is
* duplicated in a consistent fashion across drivers.
*
* It is an error to call this hook before &drm_connector.state has been
* initialized correctly.
*
* NOTE:
*
* If the duplicate state references refcounted resources this hook must
* acquire a reference for each of them. The driver must release these
* references again in @atomic_destroy_state.
*
* RETURNS:
*
* Duplicated atomic state or NULL when the allocation failed.
*/
struct drm_connector_state *(*atomic_duplicate_state)(struct drm_connector *connector);
/**
* @atomic_destroy_state:
*
* Destroy a state duplicated with @atomic_duplicate_state and release
* or unreference all resources it references
*
* This callback is mandatory for atomic drivers.
*/
void (*atomic_destroy_state)(struct drm_connector *connector,
struct drm_connector_state *state);
/**
* @atomic_set_property:
*
* Decode a driver-private property value and store the decoded value
* into the passed-in state structure. Since the atomic core decodes all
* standardized properties (even for extensions beyond the core set of
* properties which might not be implemented by all drivers) this
* requires drivers to subclass the state structure.
*
* Such driver-private properties should really only be implemented for
* truly hardware/vendor specific state. Instead it is preferred to
* standardize atomic extension and decode the properties used to expose
* such an extension in the core.
*
* Do not call this function directly, use
* drm_atomic_connector_set_property() instead.
*
* This callback is optional if the driver does not support any
* driver-private atomic properties.
*
* NOTE:
*
* This function is called in the state assembly phase of atomic
* modesets, which can be aborted for any reason (including on
* userspace's request to just check whether a configuration would be
* possible). Drivers MUST NOT touch any persistent state (hardware or
* software) or data structures except the passed in @state parameter.
*
* Also since userspace controls in which order properties are set this
* function must not do any input validation (since the state update is
* incomplete and hence likely inconsistent). Instead any such input
* validation must be done in the various atomic_check callbacks.
*
* RETURNS:
*
* 0 if the property has been found, -EINVAL if the property isn't
* implemented by the driver (which shouldn't ever happen, the core only
* asks for properties attached to this connector). No other validation
* is allowed by the driver. The core already checks that the property
* value is within the range (integer, valid enum value, ...) the driver
* set when registering the property.
*/
int (*atomic_set_property)(struct drm_connector *connector,
struct drm_connector_state *state,
struct drm_property *property,
uint64_t val);
/**
* @atomic_get_property:
*
* Reads out the decoded driver-private property. This is used to
* implement the GETCONNECTOR IOCTL.
*
* Do not call this function directly, use
* drm_atomic_connector_get_property() instead.
*
* This callback is optional if the driver does not support any
* driver-private atomic properties.
*
* RETURNS:
*
* 0 on success, -EINVAL if the property isn't implemented by the
* driver (which shouldn't ever happen, the core only asks for
* properties attached to this connector).
*/
int (*atomic_get_property)(struct drm_connector *connector,
const struct drm_connector_state *state,
struct drm_property *property,
uint64_t *val);
/**
* @atomic_print_state:
*
* If driver subclasses &struct drm_connector_state, it should implement
* this optional hook for printing additional driver specific state.
*
* Do not call this directly, use drm_atomic_connector_print_state()
* instead.
*/
void (*atomic_print_state)(struct drm_printer *p,
const struct drm_connector_state *state);
};
/**
* struct drm_connector - central DRM connector control structure
*
* Each connector may be connected to one or more CRTCs, or may be clonable by
* another connector if they can share a CRTC. Each connector also has a specific
* position in the broader display (referred to as a 'screen' though it could
* span multiple monitors).
*/
struct drm_connector {
/** @dev: parent DRM device */
struct drm_device *dev;
/** @kdev: kernel device for sysfs attributes */
struct device *kdev;
/** @attr: sysfs attributes */
struct device_attribute *attr;
/**
* @head:
*
* List of all connectors on a @dev, linked from
* &drm_mode_config.connector_list. Protected by
* &drm_mode_config.connector_list_lock, but please only use
* &drm_connector_list_iter to walk this list.
*/
struct list_head head;
/** @base: base KMS object */
struct drm_mode_object base;
/** @name: human readable name, can be overwritten by the driver */
char *name;
/**
* @mutex: Lock for general connector state, but currently only protects
* @registered. Most of the connector state is still protected by
* &drm_mode_config.mutex.
*/
struct mutex mutex;
/**
* @index: Compacted connector index, which matches the position inside
* the mode_config.list for drivers not supporting hot-add/removing. Can
* be used as an array index. It is invariant over the lifetime of the
* connector.
*/
unsigned index;
/**
* @connector_type:
* one of the DRM_MODE_CONNECTOR_<foo> types from drm_mode.h
*/
int connector_type;
/** @connector_type_id: index into connector type enum */
int connector_type_id;
/**
* @interlace_allowed:
* Can this connector handle interlaced modes? Only used by
* drm_helper_probe_single_connector_modes() for mode filtering.
*/
bool interlace_allowed;
/**
* @doublescan_allowed:
* Can this connector handle doublescan? Only used by
* drm_helper_probe_single_connector_modes() for mode filtering.
*/
bool doublescan_allowed;
/**
* @stereo_allowed:
* Can this connector handle stereo modes? Only used by
* drm_helper_probe_single_connector_modes() for mode filtering.
*/
bool stereo_allowed;
/**
* @ycbcr_420_allowed : This bool indicates if this connector is
* capable of handling YCBCR 420 output. While parsing the EDID
* blocks it's very helpful to know if the source is capable of
* handling YCBCR 420 outputs.
*/
bool ycbcr_420_allowed;
/**
* @registration_state: Is this connector initializing, exposed
* (registered) with userspace, or unregistered?
*
* Protected by @mutex.
*/
enum drm_connector_registration_state registration_state;
/**
* @modes:
* Modes available on this connector (from fill_modes() + user).
* Protected by &drm_mode_config.mutex.
*/
struct list_head modes;
/**
* @status:
* One of the drm_connector_status enums (connected, not, or unknown).
* Protected by &drm_mode_config.mutex.
*/
enum drm_connector_status status;
/**
* @probed_modes:
* These are modes added by probing with DDC or the BIOS, before
* filtering is applied. Used by the probe helpers. Protected by
* &drm_mode_config.mutex.
*/
struct list_head probed_modes;
/**
* @display_info: Display information is filled from EDID information
* when a display is detected. For non hot-pluggable displays such as
* flat panels in embedded systems, the driver should initialize the
* &drm_display_info.width_mm and &drm_display_info.height_mm fields
* with the physical size of the display.
*
* Protected by &drm_mode_config.mutex.
*/
struct drm_display_info display_info;
/** @funcs: connector control functions */
const struct drm_connector_funcs *funcs;
/**
* @edid_blob_ptr: DRM property containing EDID if present. Protected by
* &drm_mode_config.mutex. This should be updated only by calling
* drm_connector_update_edid_property().
*/
struct drm_property_blob *edid_blob_ptr;
/** @properties: property tracking for this connector */
struct drm_object_properties properties;
/**
* @scaling_mode_property: Optional atomic property to control the
* upscaling. See drm_connector_attach_content_protection_property().
*/
struct drm_property *scaling_mode_property;
/**
* @vrr_capable_property: Optional property to help userspace
* query hardware support for variable refresh rate on a connector.
* connector. Drivers can add the property to a connector by
* calling drm_connector_attach_vrr_capable_property().
*
* This should be updated only by calling
* drm_connector_set_vrr_capable_property().
*/
struct drm_property *vrr_capable_property;
/**
* @content_protection_property: DRM ENUM property for content
* protection. See drm_connector_attach_content_protection_property().
*/
struct drm_property *content_protection_property;
/**
* @path_blob_ptr:
*
* DRM blob property data for the DP MST path property. This should only
* be updated by calling drm_connector_set_path_property().
*/
struct drm_property_blob *path_blob_ptr;
/**
* @max_bpc_property: Default connector property for the max bpc to be
* driven out of the connector.
*/
struct drm_property *max_bpc_property;
#define DRM_CONNECTOR_POLL_HPD (1 << 0)
#define DRM_CONNECTOR_POLL_CONNECT (1 << 1)
#define DRM_CONNECTOR_POLL_DISCONNECT (1 << 2)
/**
* @polled:
*
* Connector polling mode, a combination of
*
* DRM_CONNECTOR_POLL_HPD
* The connector generates hotplug events and doesn't need to be
* periodically polled. The CONNECT and DISCONNECT flags must not
* be set together with the HPD flag.
*
* DRM_CONNECTOR_POLL_CONNECT
* Periodically poll the connector for connection.
*
* DRM_CONNECTOR_POLL_DISCONNECT
* Periodically poll the connector for disconnection, without
* causing flickering even when the connector is in use. DACs should
* rarely do this without a lot of testing.
*
* Set to 0 for connectors that don't support connection status
* discovery.
*/
uint8_t polled;
/**
* @dpms: Current dpms state. For legacy drivers the
* &drm_connector_funcs.dpms callback must update this. For atomic
* drivers, this is handled by the core atomic code, and drivers must
* only take &drm_crtc_state.active into account.
*/
int dpms;
/** @helper_private: mid-layer private data */
const struct drm_connector_helper_funcs *helper_private;
/** @cmdline_mode: mode line parsed from the kernel cmdline for this connector */
struct drm_cmdline_mode cmdline_mode;
/** @force: a DRM_FORCE_<foo> state for forced mode sets */
enum drm_connector_force force;
/** @override_edid: has the EDID been overwritten through debugfs for testing? */
bool override_edid;
#define DRM_CONNECTOR_MAX_ENCODER 3
/**
* @encoder_ids: Valid encoders for this connector. Please only use
* drm_connector_for_each_possible_encoder() to enumerate these.
*/
uint32_t encoder_ids[DRM_CONNECTOR_MAX_ENCODER];
/**
* @encoder: Currently bound encoder driving this connector, if any.
* Only really meaningful for non-atomic drivers. Atomic drivers should
* instead look at &drm_connector_state.best_encoder, and in case they
* need the CRTC driving this output, &drm_connector_state.crtc.
*/
struct drm_encoder *encoder;
#define MAX_ELD_BYTES 128
/** @eld: EDID-like data, if present */
uint8_t eld[MAX_ELD_BYTES];
/** @latency_present: AV delay info from ELD, if found */
bool latency_present[2];
/**
* @video_latency: Video latency info from ELD, if found.
* [0]: progressive, [1]: interlaced
*/
int video_latency[2];
/**
* @audio_latency: audio latency info from ELD, if found
* [0]: progressive, [1]: interlaced
*/
int audio_latency[2];
/**
* @null_edid_counter: track sinks that give us all zeros for the EDID.
* Needed to workaround some HW bugs where we get all 0s
*/
int null_edid_counter;
/** @bad_edid_counter: track sinks that give us an EDID with invalid checksum */
unsigned bad_edid_counter;
/**
* @edid_corrupt: Indicates whether the last read EDID was corrupt. Used
* in Displayport compliance testing - Displayport Link CTS Core 1.2
* rev1.1 4.2.2.6
*/
bool edid_corrupt;
/** @debugfs_entry: debugfs directory for this connector */
struct dentry *debugfs_entry;
/**
* @state:
*
* Current atomic state for this connector.
*
* This is protected by &drm_mode_config.connection_mutex. Note that
* nonblocking atomic commits access the current connector state without
* taking locks. Either by going through the &struct drm_atomic_state
* pointers, see for_each_oldnew_connector_in_state(),
* for_each_old_connector_in_state() and
* for_each_new_connector_in_state(). Or through careful ordering of
* atomic commit operations as implemented in the atomic helpers, see
* &struct drm_crtc_commit.
*/
struct drm_connector_state *state;
/* DisplayID bits. FIXME: Extract into a substruct? */
/**
* @tile_blob_ptr:
*
* DRM blob property data for the tile property (used mostly by DP MST).
* This is meant for screens which are driven through separate display
* pipelines represented by &drm_crtc, which might not be running with
* genlocked clocks. For tiled panels which are genlocked, like
* dual-link LVDS or dual-link DSI, the driver should try to not expose
* the tiling and virtualize both &drm_crtc and &drm_plane if needed.
*
* This should only be updated by calling
* drm_connector_set_tile_property().
*/
struct drm_property_blob *tile_blob_ptr;
/** @has_tile: is this connector connected to a tiled monitor */
bool has_tile;
/** @tile_group: tile group for the connected monitor */
struct drm_tile_group *tile_group;
/** @tile_is_single_monitor: whether the tile is one monitor housing */
bool tile_is_single_monitor;
/** @num_h_tile: number of horizontal tiles in the tile group */
/** @num_v_tile: number of vertical tiles in the tile group */
uint8_t num_h_tile, num_v_tile;
/** @tile_h_loc: horizontal location of this tile */
/** @tile_v_loc: vertical location of this tile */
uint8_t tile_h_loc, tile_v_loc;
/** @tile_h_size: horizontal size of this tile. */
/** @tile_v_size: vertical size of this tile. */
uint16_t tile_h_size, tile_v_size;
/**
* @free_node:
*
* List used only by &drm_connector_list_iter to be able to clean up a
* connector from any context, in conjunction with
* &drm_mode_config.connector_free_work.
*/
struct llist_node free_node;
};
/msm/Makefile:42: sde/sde_connector.o \
./msm/Makefile:58: hdmi/hdmi_connector.o \
./msm/Makefile:68: edp/edp_connector.o \
./Makefile:17: drm_framebuffer.o drm_connector.o drm_blend.o \
Hdmi_connector.c 此文件諸多關聯相關hdmi文件
_hdmi_connector_init裏面有：
+msm-hdmi-hotplug-work
+drm_connector_init（添加hdmi_connector_funcs）
+drm_connector_helper_add（添加msm_hdmi_connector_helper_funs）
+hpd_enable
+drm_mode_connector_attach_encoder
Hpd_enable裏面有：
+enable_hpd_clock
+ hdmi_set_mode
+ hdmi_phy_reset
Edp_connector.c 關聯edp_crtl.c
_edp_connector_init
+drm_connector_init
+drm_connector_helper_add
+drm_mode_connector_attach_encoder