diff options
Diffstat (limited to 'include/drm/drm_bridge.h')
-rw-r--r-- | include/drm/drm_bridge.h | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index ae0595c70132..46e15526b087 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -36,6 +36,38 @@ struct drm_bridge_timings; struct drm_panel; /** + * struct drm_bus_cfg - bus configuration + * + * This structure stores the configuration of a physical bus between two + * components in an output pipeline, usually between two bridges, an encoder + * and a bridge, or a bridge and a connector. + * + * The bus configuration is stored in &drm_bridge_state separately for the + * input and output buses, as seen from the point of view of each bridge. The + * bus configuration of a bridge output is usually identical to the + * configuration of the next bridge's input, but may differ if the signals are + * modified between the two bridges, for instance by an inverter on the board. + * The input and output configurations of a bridge may differ if the bridge + * modifies the signals internally, for instance by performing format + * conversion, or modifying signals polarities. + */ +struct drm_bus_cfg { + /** + * @format: format used on this bus (one of the MEDIA_BUS_FMT_* format) + * + * This field should not be directly modified by drivers + * (&drm_atomic_bridge_chain_select_bus_fmts() takes care of the bus + * format negotiation). + */ + u32 format; + + /** + * @flags: DRM_BUS_* flags used on this bus + */ + u32 flags; +}; + +/** * struct drm_bridge_state - Atomic bridge state object * @base: inherit from &drm_private_state * @bridge: the bridge this state refers to @@ -44,6 +76,16 @@ struct drm_bridge_state { struct drm_private_state base; struct drm_bridge *bridge; + + /** + * @input_bus_cfg: input bus configuration + */ + struct drm_bus_cfg input_bus_cfg; + + /** + * @output_bus_cfg: input bus configuration + */ + struct drm_bus_cfg output_bus_cfg; }; static inline struct drm_bridge_state * @@ -388,6 +430,72 @@ struct drm_bridge_funcs { struct drm_bridge_state *state); /** + * @atomic_get_output_bus_fmts: + * + * Return the supported bus formats on the output end of a bridge. + * The returned array must be allocated with kmalloc() and will be + * freed by the caller. If the allocation fails, NULL should be + * returned. num_output_fmts must be set to the returned array size. + * Formats listed in the returned array should be listed in decreasing + * preference order (the core will try all formats until it finds one + * that works). + * + * This method is only called on the last element of the bridge chain + * as part of the bus format negotiation process that happens in + * &drm_atomic_bridge_chain_select_bus_fmts(). + * This method is optional. When not implemented, the core will + * fall back to &drm_connector.display_info.bus_formats[0] if + * &drm_connector.display_info.num_bus_formats > 0, + * or to MEDIA_BUS_FMT_FIXED otherwise. + */ + u32 *(*atomic_get_output_bus_fmts)(struct drm_bridge *bridge, + struct drm_bridge_state *bridge_state, + struct drm_crtc_state *crtc_state, + struct drm_connector_state *conn_state, + unsigned int *num_output_fmts); + + /** + * @atomic_get_input_bus_fmts: + * + * Return the supported bus formats on the input end of a bridge for + * a specific output bus format. + * + * The returned array must be allocated with kmalloc() and will be + * freed by the caller. If the allocation fails, NULL should be + * returned. num_output_fmts must be set to the returned array size. + * Formats listed in the returned array should be listed in decreasing + * preference order (the core will try all formats until it finds one + * that works). When the format is not supported NULL should be + * returned and *num_output_fmts should be set to 0. + * + * This method is called on all elements of the bridge chain as part of + * the bus format negotiation process that happens in + * &drm_atomic_bridge_chain_select_bus_fmts(). + * This method is optional. When not implemented, the core will bypass + * bus format negotiation on this element of the bridge without + * failing, and the previous element in the chain will be passed + * MEDIA_BUS_FMT_FIXED as its output bus format. + * + * Bridge drivers that need to support being linked to bridges that are + * not supporting bus format negotiation should handle the + * output_fmt == MEDIA_BUS_FMT_FIXED case appropriately, by selecting a + * sensible default value or extracting this information from somewhere + * else (FW property, &drm_display_mode, &drm_display_info, ...) + * + * Note: Even if input format selection on the first bridge has no + * impact on the negotiation process (bus format negotiation stops once + * we reach the first element of the chain), drivers are expected to + * return accurate input formats as the input format may be used to + * configure the CRTC output appropriately. + */ + u32 *(*atomic_get_input_bus_fmts)(struct drm_bridge *bridge, + struct drm_bridge_state *bridge_state, + struct drm_crtc_state *crtc_state, + struct drm_connector_state *conn_state, + u32 output_fmt, + unsigned int *num_input_fmts); + + /** * @atomic_check: * * This method is responsible for checking bridge state correctness. @@ -401,6 +509,14 @@ struct drm_bridge_funcs { * called when &drm_bridge_funcs.atomic_check() is implemented, so only * one of them should be provided. * + * If drivers need to tweak &drm_bridge_state.input_bus_cfg.flags or + * &drm_bridge_state.output_bus_cfg.flags it should should happen in + * this function. By default the &drm_bridge_state.output_bus_cfg.flags + * field is set to the next bridge + * &drm_bridge_state.input_bus_cfg.flags value or + * &drm_connector.display_info.bus_flags if the bridge is the last + * element in the chain. + * * RETURNS: * zero if the check passed, a negative error code otherwise. */ @@ -588,6 +704,14 @@ void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge, void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge, struct drm_atomic_state *state); +u32 * +drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge, + struct drm_bridge_state *bridge_state, + struct drm_crtc_state *crtc_state, + struct drm_connector_state *conn_state, + u32 output_fmt, + unsigned int *num_input_fmts); + void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge, struct drm_bridge_state *state); void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge, |