SYNOPSIS

struct drm_bridge_funcs {
int (* attach) (struct drm_bridge *bridge);
bool (* mode_fixup) (struct drm_bridge *bridge,const struct drm_display_mode *mode,struct drm_display_mode *adjusted_mode);
void (* disable) (struct drm_bridge *bridge);
void (* post_disable) (struct drm_bridge *bridge);
void (* mode_set) (struct drm_bridge *bridge,struct drm_display_mode *mode,struct drm_display_mode *adjusted_mode);
void (* pre_enable) (struct drm_bridge *bridge);
void (* enable) (struct drm_bridge *bridge);
};

MEMBERS

attach

Called during drm_bridge_attach

mode_fixup

This callback is used to validate and adjust a mode. The paramater 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.

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.

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.

RETURNS:

True if an acceptable configuration is possible, false if the modeset operation should be rejected.

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 function. If the preceding element is a drm_encoder it's called right before the encoder's ->disable, ->prepare or ->dpms hook from struct drm_encoder_helper_funcs.

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.

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 ->disable, ->prepare or ->dpms hook from struct drm_encoder_helper_funcs.

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.

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. The display pipe (i.e. clocks and timing signals) is off when this function is called.

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 ->enable, ->commit or ->dpms hook from struct drm_encoder_helper_funcs.

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.

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 ->enable, ->commit or ->dpms hook from struct drm_encoder_helper_funcs.

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.

AUTHORS

Jesse Barnes <[email protected]>
Intel Corporation,         
        

Initial version

Laurent Pinchart <[email protected]>
Ideas on board SPRL,         
        

Driver internals

Daniel Vetter <[email protected]>
Intel Corporation,         
        

Contributions all over the place

Lukas Wunner <[email protected]>

vga_switcheroo documentation

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