https://bootlin.com/doc/training/graphics/graphics-slides.pdf
/**
* struct drm_bridge - central DRM bridge control structure
*/
struct drm_bridge {
/** @dev: DRM device this bridge belongs to */
struct drm_device *dev;
/** @encoder: encoder to which this bridge is connected */
struct drm_encoder *encoder;
/** @next: the next bridge in the encoder chain */
struct drm_bridge *next;
#ifdef CONFIG_OF
/** @of_node: device node pointer to the bridge */
struct device_node *of_node;
#endif
/** @list: to keep track of all added bridges */
struct list_head list;
/**
* @timings:
*
* the timing specification for the bridge, if any (may be NULL)
*/
const struct drm_bridge_timings *timings;
/** @funcs: control functions */
const struct drm_bridge_funcs *funcs;
/** @driver_private: pointer to the bridge driver's internal context */
void *driver_private;
};
/**
* struct drm_bridge_funcs - drm_bridge control functions
*/
struct drm_bridge_funcs {
/**
* @attach:
*
* This callback is invoked whenever our bridge is being attached to a
* &drm_encoder.
*
* The attach callback is optional.
*
* RETURNS:
*
* Zero on success, error code on failure.
*/
int (*attach)(struct drm_bridge *bridge);
/**
* @detach:
*
* This callback is invoked whenever our bridge is being detached from a
* &drm_encoder.
*
* The detach callback is optional.
*/
void (*detach)(struct drm_bridge *bridge);
/**
* @mode_valid:
*
* This callback is used to check if a specific mode is valid in this
* bridge. This should be implemented if the bridge has some sort of
* restriction in the modes it can display. For example, a given bridge
* may be responsible to set a clock value. If the clock can not
* produce all the values for the available modes then this callback
* can be used to restrict the number of modes to only the ones that
* can be displayed.
*
* This hook is used by the probe helpers to filter the mode list in
* drm_helper_probe_single_connector_modes(), and it is used by the
* atomic helpers to validate modes supplied by userspace in
* drm_atomic_helper_check_modeset().
*
* This function is optional.
*
* NOTE:
*
* Since this function is both called from the check phase of an atomic
* commit, and the mode validation in the probe paths it is not allowed
* to look at anything else but the passed-in mode, and validate it
* against configuration-invariant hardward constraints. Any further
* limits which depend upon the configuration can only be checked in
* @mode_fixup.
*
* RETURNS:
*
* drm_mode_status Enum
*/
enum drm_mode_status (*mode_valid)(struct drm_bridge *bridge,
const struct drm_display_mode *mode);
/**
* @mode_fixup:
*
* This callback is used to validate and adjust a mode. The parameter
* mode is the display mode that should be fed to the next element in
* the display chain, either the final &drm_connector or the next
* &drm_bridge. The parameter adjusted_mode is the input mode the bridge
* requires. It can be modified by this callback and does not need to
* match mode. See also &drm_crtc_state.adjusted_mode for more details.
*
* This is the only hook that allows a bridge to reject a modeset. If
* this function passes all other callbacks must succeed for this
* configuration.
*
* The mode_fixup callback is optional.
*
* NOTE:
*
* This function is called in the check 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 beware that userspace can request its own custom modes, neither
* core nor helpers filter modes to the list of probe modes reported by
* the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
* that modes are filtered consistently put any bridge constraints and
* limits checks into @mode_valid.
*
* RETURNS:
*
* True if an acceptable configuration is possible, false if the modeset
* operation should be rejected.
*/
bool (*mode_fixup)(struct drm_bridge *bridge,
const struct drm_display_mode *mode,
struct drm_display_mode *adjusted_mode);
/**
* @disable:
*
* This callback should disable the bridge. It is called right before
* the preceding element in the display pipe is disabled. If the
* preceding element is a bridge this means it's called before that
* bridge's @disable vfunc. If the preceding element is a &drm_encoder
* it's called right before the &drm_encoder_helper_funcs.disable,
* &drm_encoder_helper_funcs.prepare or &drm_encoder_helper_funcs.dpms
* hook.
*
* The bridge can assume that the display pipe (i.e. clocks and timing
* signals) feeding it is still running when this callback is called.
*
* The disable callback is optional.
*/
void (*disable)(struct drm_bridge *bridge);
/**
* @post_disable:
*
* This callback should disable the bridge. It is called right after the
* preceding element in the display pipe is disabled. If the preceding
* element is a bridge this means it's called after that bridge's
* @post_disable function. If the preceding element is a &drm_encoder
* it's called right after the encoder's
* &drm_encoder_helper_funcs.disable, &drm_encoder_helper_funcs.prepare
* or &drm_encoder_helper_funcs.dpms hook.
*
* The bridge must assume that the display pipe (i.e. clocks and timing
* singals) feeding it is no longer running when this callback is
* called.
*
* The post_disable callback is optional.
*/
void (*post_disable)(struct drm_bridge *bridge);
/**
* @mode_set:
*
* This callback should set the given mode on the bridge. It is called
* after the @mode_set callback for the preceding element in the display
* pipeline has been called already. If the bridge is the first element
* then this would be &drm_encoder_helper_funcs.mode_set. The display
* pipe (i.e. clocks and timing signals) is off when this function is
* called.
*
* The adjusted_mode parameter is the mode output by the CRTC for the
* first bridge in the chain. It can be different from the mode
* parameter that contains the desired mode for the connector at the end
* of the bridges chain, for instance when the first bridge in the chain
* performs scaling. The adjusted mode is mostly useful for the first
* bridge in the chain and is likely irrelevant for the other bridges.
*
* For atomic drivers the adjusted_mode is the mode stored in
* &drm_crtc_state.adjusted_mode.
*
* NOTE:
*
* If a need arises to store and access modes adjusted for other
* locations than the connection between the CRTC and the first bridge,
* the DRM framework will have to be extended with DRM bridge states.
*/
void (*mode_set)(struct drm_bridge *bridge,
const struct drm_display_mode *mode,
const struct drm_display_mode *adjusted_mode);
/**
* @pre_enable:
*
* This callback should enable the bridge. It is called right before
* the preceding element in the display pipe is enabled. If the
* preceding element is a bridge this means it's called before that
* bridge's @pre_enable function. If the preceding element is a
* &drm_encoder it's called right before the encoder's
* &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
* &drm_encoder_helper_funcs.dpms hook.
*
* The display pipe (i.e. clocks and timing signals) feeding this bridge
* will not yet be running when this callback is called. The bridge must
* not enable the display link feeding the next bridge in the chain (if
* there is one) when this callback is called.
*
* The pre_enable callback is optional.
*/
void (*pre_enable)(struct drm_bridge *bridge);
/**
* @enable:
*
* This callback should enable the bridge. It is called right after
* the preceding element in the display pipe is enabled. If the
* preceding element is a bridge this means it's called after that
* bridge's @enable function. If the preceding element is a
* &drm_encoder it's called right after the encoder's
* &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
* &drm_encoder_helper_funcs.dpms hook.
*
* The bridge can assume that the display pipe (i.e. clocks and timing
* signals) feeding it is running when this callback is called. This
* callback must enable the display link feeding the next bridge in the
* chain if there is one.
*
* The enable callback is optional.
*/
void (*enable)(struct drm_bridge *bridge);
};
./msm/Makefile: hdmi/hdmi_bridge.o \
./msm/Makefile: edp/edp_bridge.o \
./Makefile: drm_modeset_lock.o drm_atomic.o drm_bridge.o \
./Makefile:drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o
./Makefile:obj-y += bridge/
Hdmi_bridge.c 全部代码围绕drm-bridge-funcs实现。开启关闭设备+模式设置【设置hdmi寄存器，配置regulator】
_hdmi_bridge_init 包含
+drm_bridge_attach
+bridge->funcs = &msm_hdmi_bridge_funcs;
static const struct drm_bridge_funcs msm_hdmi_bridge_funcs = {
.pre_enable = msm_hdmi_bridge_pre_enable,
.enable = msm_hdmi_bridge_enable,
.disable = msm_hdmi_bridge_disable,
.post_disable = msm_hdmi_bridge_post_disable,
.mode_set = msm_hdmi_bridge_mode_set,
};
msm_hdmi_bridge_mode_set设置h,v等分辨率的大小
+hdmi_write
+msm_hdmi_audio_update
msm_hdmi_config_avi_infoframe
Edp_bridge.c
_edp_bridge_init
+ bridge->funcs = &edp_bridge_funcs;
+ drm_bridge_attach
static const struct drm_bridge_funcs edp_bridge_funcs = {
.pre_enable = edp_bridge_pre_enable,
.enable = edp_bridge_enable,
.disable = edp_bridge_disable,
.post_disable = edp_bridge_post_disable,
.mode_set = edp_bridge_mode_set,
};
edp_bridge_mode_set
+ msm_edp_ctrl_timing_cfg