Revert "drm/bridge: Add the necessary bits to support bus format negotiation"

This reverts commit e351e4d5eaec ("drm/bridge: Add the necessary bits
to support bus format negotiation"). Commit 6ed7e9625fa6 ("drm/bridge:
Add a drm_bridge_state object") introduced a circular dependency
between drm.ko and drm_kms_helper.ko which uncovered a misdesign in
how the whole thing was implemented. Let's revert all patches depending
on the bridge_state infrastructure for now.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200107185807.606999-3-boris.brezillon@collabora.com

1 files changed, 0 insertions, 124 deletions

diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 46e15526b087..ae0595c70132 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -36,38 +36,6 @@ 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
@@ -76,16 +44,6 @@ 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 *
@@ -430,72 +388,6 @@ 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.
@@ -509,14 +401,6 @@ 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.
 	 */
@@ -704,14 +588,6 @@ 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,