user/sven/linux.git/drivers/gpu/drm/drm_bridge.c, branch v5.7

drm: Add helper to create a connector for a chain of bridges

2020-02-26T11:31:41Z

drm/bridge: Extend bridge API to disable connector creation

2020-02-26T11:31:23Z

Most bridge drivers create a DRM connector to model the connector at the output of the bridge. This model is historical and has worked pretty well so far, but causes several issues: - It prevents supporting more complex display pipelines where DRM connector operations are split over multiple components. For instance a pipeline with a bridge connected to the DDC signals to read EDID data, and another one connected to the HPD signal to detect connection and disconnection, will not be possible to support through this model. - It requires every bridge driver to implement similar connector handling code, resulting in code duplication. - It assumes that a bridge will either be wired to a connector or to another bridge, but doesn't support bridges that can be used in both positions very well (although there is some ad-hoc support for this in the analogix_dp bridge driver). In order to solve these issues, ownership of the connector should be moved to the display controller driver (where it can be implemented using helpers provided by the core). Extend the bridge API to allow disabling connector creation in bridge drivers as a first step towards the new model. The new flags argument to the bridge .attach() operation allows instructing the bridge driver to skip creating a connector. Unconditionally set the new flags argument to 0 for now to keep the existing behaviour, and modify all existing bridge drivers to return an error when connector creation is not requested as they don't support this feature yet. The change is based on the following semantic patch, with manual review and edits. @ rule1 @ identifier funcs; identifier fn; @@ struct drm_bridge_funcs funcs = { ..., .attach = fn }; @ depends on rule1 @ identifier rule1.fn; identifier bridge; statement S, S1; @@ int fn( struct drm_bridge *bridge + , enum drm_bridge_attach_flags flags ) { ... when != S + if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) { + DRM_ERROR("Fix bridge driver to make connector optional!"); + return -EINVAL; + } + S1 ... } @ depends on rule1 @ identifier rule1.fn; identifier bridge, flags; expression E1, E2, E3; @@ int fn( struct drm_bridge *bridge, enum drm_bridge_attach_flags flags ) { <... drm_bridge_attach(E1, E2, E3 + , flags ) ...> } @@ expression E1, E2, E3; @@ drm_bridge_attach(E1, E2, E3 + , 0 ) Signed-off-by: Laurent Pinchart Reviewed-by: Boris Brezillon Acked-by: Sam Ravnborg Reviewed-by: Tomi Valkeinen Tested-by: Sebastian Reichel Reviewed-by: Sebastian Reichel Acked-by: Daniel Vetter Signed-off-by: Tomi Valkeinen Link: https://patchwork.freedesktop.org/patch/msgid/20200226112514.12455-10-laurent.pinchart@ideasonboard.com

drm/bridge: Add connector-related bridge operations and data

2020-02-26T11:31:22Z

To support implementation of DRM connectors on top of DRM bridges instead of by bridges, the drm_bridge needs to expose new operations and data: - Output detection, hot-plug notification, mode retrieval and EDID retrieval operations - Bitmask of supported operations - Bridge output type - I2C adapter for DDC access Add and document these. Three new bridge helper functions are also added to handle hot plug notification in a way that is as transparent as possible for the bridges. Signed-off-by: Laurent Pinchart Reviewed-by: Boris Brezillon Reviewed-by: Sam Ravnborg Tested-by: Sebastian Reichel Reviewed-by: Sebastian Reichel Acked-by: Daniel Vetter Signed-off-by: Tomi Valkeinen Link: https://patchwork.freedesktop.org/patch/msgid/20200226112514.12455-8-laurent.pinchart@ideasonboard.com

drm/bridge: Improve overview documentation

2020-02-26T11:31:21Z

Clean up the drm_bridge overview documentation, and expand the operations documentation to provide more details on API usage. Signed-off-by: Laurent Pinchart Reviewed-by: Daniel Vetter Signed-off-by: Tomi Valkeinen Link: https://patchwork.freedesktop.org/patch/msgid/20200226112514.12455-7-laurent.pinchart@ideasonboard.com

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

2020-01-31T15:39:53Z

drm_bridge_state is extended to describe the input and output bus configurations. These bus configurations are exposed through the drm_bus_cfg struct which encodes 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. Bus format negotiation is automated by the core, drivers just have to implement the ->atomic_get_{output,input}_bus_fmts() hooks if they want to take part to this negotiation. Negotiation happens in reverse order, starting from the last element of the chain (the one directly connected to the display) up to the first element of the chain (the one connected to the encoder). During this negotiation all supported formats are tested until we find one that works, meaning that the formats array should be in decreasing preference order (assuming the driver has a preference order). Note that the bus format negotiation works even if some elements in the chain don't implement the ->atomic_get_{output,input}_bus_fmts() hooks. In that case, the core advertises only MEDIA_BUS_FMT_FIXED and lets the previous bridge element decide what to do (most of the time, bridge drivers will pick a default bus format or extract this piece of information from somewhere else, like a FW property). v10: * Add changelog to the commit message v9: * No changes v8: * Fix a test in drm_atomic_bridge_chain_select_bus_fmts() (Reported by Jonas) v7: * Adapt the code to deal with the fact that not all bridges in the chain have a bridge state v5 -> v6: * No changes v4: * Enhance the doc * Fix typos * Rename some parameters/fields * Reword the commit message v3: * Fix the commit message (Reported by Laurent) * Document the fact that bus formats should not be directly modified by drivers (Suggested by Laurent) * Document the fact that format order matters (Suggested by Laurent) * Propagate bus flags by default * Document the fact that drivers can tweak bus flags if needed * Let ->atomic_get_{output,input}_bus_fmts() allocate the bus format array (Suggested by Laurent) * Add a drm_atomic_helper_bridge_propagate_bus_fmt() * Mandate that bridge drivers return accurate input_fmts even if they are known to be the first element in the bridge chain v2: * Rework things to support more complex use cases Signed-off-by: Boris Brezillon Signed-off-by: Neil Armstrong [narmstrong: fixed doc in include/drm/drm_bridge.h:69 fmt->format] Reviewed-by: Jernej Skrabec Tested-by: Jonas Karlman Link: https://patchwork.freedesktop.org/patch/msgid/20200128135514.108171-7-boris.brezillon@collabora.com

drm/bridge: Add an ->atomic_check() hook

2020-01-31T15:00:25Z

So that bridge drivers have a way to check/reject an atomic operation. The drm_atomic_bridge_chain_check() (which is just a wrapper around the ->atomic_check() hook) is called in place of drm_bridge_chain_mode_fixup() (when ->atomic_check() is not implemented, the core falls back on ->mode_fixup(), so the behavior should stay the same for existing bridge drivers). v10: * Add changelog to the commit message v8 -> v9: * No changes v7: * Fix a NULL pointer dereference v5 -> v6: * No changes v4: * Add R-bs v3: * No changes v2: * Clarify the fact that ->atomic_check() is replacing ->mode_fixup() Signed-off-by: Boris Brezillon Reviewed-by: Neil Armstrong Reviewed-by: Laurent Pinchart Signed-off-by: Neil Armstrong Reviewed by: Jernej Skrabec Tested-by: Jonas Karlman Link: https://patchwork.freedesktop.org/patch/msgid/20200128135514.108171-6-boris.brezillon@collabora.com

drm/bridge: Patch atomic hooks to take a drm_bridge_state

2020-01-31T15:00:24Z

This way the drm_bridge_funcs interface is consistent with the rest of the subsystem. The drivers implementing those hooks are patched too. v10: * Add changelog to the commit message v8 -> v9: * No changes v7: * Adjust things to the bridge_state changes v6: * Also fixed rcar-du/rcar_lvds.c same as analogix/analogix_dp_core.c v5: * No changes v4: * Rename func params into old_bridge_state * Add Laurent's Rb v3: * Old state clarification moved to a separate patch v2: * Pass the old bridge state Signed-off-by: Boris Brezillon Reviewed-by: Laurent Pinchart Signed-off-by: Neil Armstrong [narmstrong: renamed state as old_bridge_state in rcar_lvds_atomic_disable] Reviewed by: Jernej Skrabec Tested-by: Jonas Karlman Link: https://patchwork.freedesktop.org/patch/msgid/20200128135514.108171-5-boris.brezillon@collabora.com

drm/bridge: Add a drm_bridge_state object

2020-01-31T15:00:21Z

One of the last remaining objects to not have its atomic state. This is being motivated by our attempt to support runtime bus-format negotiation between elements of the bridge chain. This patch just paves the road for such a feature by adding a new drm_bridge_state object inheriting from drm_private_obj so we can re-use some of the existing state initialization/tracking logic. v10: * Add changelog to the commit message v9: * Clarify the fact that the bridge->atomic_reset() and {connector,plane,crtc,...}->reset() semantics are different * Move the drm_atomic_private_obj_init() call back to drm_bridge_attach() * Check the presence of ->atomic_duplicate_state instead of ->atomic_reset in drm_atomic_add_encoder_bridges() * Fix copy&paste errors in the atomic bridge state helpers doc * Add A-b/R-b tags v8: * Move bridge state helpers out of the CONFIG_DEBUGFS section v7: * Move helpers, struct-defs, ... to atomic helper files to avoid the drm -> drm_kms_helper -> drm circular dep * Stop providing default implementation for atomic state reset, duplicate and destroy hooks (has to do with the helper/core split) * Drop all R-b/T-b as helpers have now be moved to other places v6: * Made helpers private, removed doc and moved them to satisfy dependencies * Renamed helpers to _default_ v5: * Re-introduced the helpers from v4 v4: * Fix the doc * Kill default helpers (inlined) * Fix drm_atomic_get_bridge_state() to check for an ERR_PTR() * Add Neil's R-b v3: * No changes v2: * Use drm_for_each_bridge_in_chain() * Rename helpers to be more consistent with the rest of the DRM API * Improve/fix the doc Signed-off-by: Boris Brezillon Signed-off-by: Neil Armstrong Reviewed-by: Neil Armstrong Acked-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20200128135514.108171-2-boris.brezillon@collabora.com

Revert "drm/bridge: Add a drm_bridge_state object"

2020-01-07T23:34:34Z

This reverts commit 6ed7e9625fa6 ("drm/bridge: Add a drm_bridge_state object") which introduced a circular dependency between drm.ko and drm_kms_helper.ko. Looks like the helper/core split is not appropriate and fixing that is not simple. Signed-off-by: Boris Brezillon Acked-by: Neil Armstrong Link: https://patchwork.freedesktop.org/patch/msgid/20200107185807.606999-6-boris.brezillon@collabora.com

Revert "drm/bridge: Patch atomic hooks to take a drm_bridge_state"

2020-01-07T23:34:28Z

This reverts commit f7619a58ef92 ("drm/bridge: Patch atomic hooks to take a drm_bridge_state"). 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 Acked-by: Neil Armstrong Link: https://patchwork.freedesktop.org/patch/msgid/20200107185807.606999-5-boris.brezillon@collabora.com