| /* |
| * Copyright (c) 2014 Samsung Electronics Co., Ltd |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sub license, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the |
| * next paragraph) shall be included in all copies or substantial portions |
| * of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
| * DEALINGS IN THE SOFTWARE. |
| */ |
| |
| #include <linux/err.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| |
| #include <drm/drm_atomic_state_helper.h> |
| #include <drm/drm_bridge.h> |
| #include <drm/drm_encoder.h> |
| #include <drm/drm_print.h> |
| |
| #include "drm_crtc_internal.h" |
| |
| /** |
| * DOC: overview |
| * |
| * &struct drm_bridge represents a device that hangs on to an encoder. These are |
| * handy when a regular &drm_encoder entity isn't enough to represent the entire |
| * encoder chain. |
| * |
| * A bridge is always attached to a single &drm_encoder at a time, but can be |
| * either connected to it directly, or through a chain of bridges:: |
| * |
| * [ CRTC ---> ] Encoder ---> Bridge A ---> Bridge B |
| * |
| * Here, the output of the encoder feeds to bridge A, and that furthers feeds to |
| * bridge B. Bridge chains can be arbitrarily long, and shall be fully linear: |
| * Chaining multiple bridges to the output of a bridge, or the same bridge to |
| * the output of different bridges, is not supported. |
| * |
| * Display drivers are responsible for linking encoders with the first bridge |
| * in the chains. This is done by acquiring the appropriate bridge with |
| * of_drm_find_bridge() or drm_of_find_panel_or_bridge(), or creating it for a |
| * panel with drm_panel_bridge_add_typed() (or the managed version |
| * devm_drm_panel_bridge_add_typed()). Once acquired, the bridge shall be |
| * attached to the encoder with a call to drm_bridge_attach(). |
| * |
| * Bridges are responsible for linking themselves with the next bridge in the |
| * chain, if any. This is done the same way as for encoders, with the call to |
| * drm_bridge_attach() occurring in the &drm_bridge_funcs.attach operation. |
| * |
| * Once these links are created, the bridges can participate along with encoder |
| * functions to perform mode validation and fixup (through |
| * drm_bridge_chain_mode_valid() and drm_atomic_bridge_chain_check()), mode |
| * setting (through drm_bridge_chain_mode_set()), enable (through |
| * drm_atomic_bridge_chain_pre_enable() and drm_atomic_bridge_chain_enable()) |
| * and disable (through drm_atomic_bridge_chain_disable() and |
| * drm_atomic_bridge_chain_post_disable()). Those functions call the |
| * corresponding operations provided in &drm_bridge_funcs in sequence for all |
| * bridges in the chain. |
| * |
| * For display drivers that use the atomic helpers |
| * drm_atomic_helper_check_modeset(), |
| * drm_atomic_helper_commit_modeset_enables() and |
| * drm_atomic_helper_commit_modeset_disables() (either directly in hand-rolled |
| * commit check and commit tail handlers, or through the higher-level |
| * drm_atomic_helper_check() and drm_atomic_helper_commit_tail() or |
| * drm_atomic_helper_commit_tail_rpm() helpers), this is done transparently and |
| * requires no intervention from the driver. For other drivers, the relevant |
| * DRM bridge chain functions shall be called manually. |
| * |
| * Bridges also participate in implementing the &drm_connector at the end of |
| * the bridge chain. Display drivers may use the drm_bridge_connector_init() |
| * helper to create the &drm_connector, or implement it manually on top of the |
| * connector-related operations exposed by the bridge (see the overview |
| * documentation of bridge operations for more details). |
| * |
| * &drm_bridge, like &drm_panel, aren't &drm_mode_object entities like planes, |
| * CRTCs, encoders or connectors and hence are not visible to userspace. They |
| * just provide additional hooks to get the desired output at the end of the |
| * encoder chain. |
| */ |
| |
| static DEFINE_MUTEX(bridge_lock); |
| static LIST_HEAD(bridge_list); |
| |
| /** |
| * drm_bridge_add - add the given bridge to the global bridge list |
| * |
| * @bridge: bridge control structure |
| */ |
| void drm_bridge_add(struct drm_bridge *bridge) |
| { |
| mutex_init(&bridge->hpd_mutex); |
| |
| mutex_lock(&bridge_lock); |
| list_add_tail(&bridge->list, &bridge_list); |
| mutex_unlock(&bridge_lock); |
| } |
| EXPORT_SYMBOL(drm_bridge_add); |
| |
| /** |
| * drm_bridge_remove - remove the given bridge from the global bridge list |
| * |
| * @bridge: bridge control structure |
| */ |
| void drm_bridge_remove(struct drm_bridge *bridge) |
| { |
| mutex_lock(&bridge_lock); |
| list_del_init(&bridge->list); |
| mutex_unlock(&bridge_lock); |
| |
| mutex_destroy(&bridge->hpd_mutex); |
| } |
| EXPORT_SYMBOL(drm_bridge_remove); |
| |
| static struct drm_private_state * |
| drm_bridge_atomic_duplicate_priv_state(struct drm_private_obj *obj) |
| { |
| struct drm_bridge *bridge = drm_priv_to_bridge(obj); |
| struct drm_bridge_state *state; |
| |
| state = bridge->funcs->atomic_duplicate_state(bridge); |
| return state ? &state->base : NULL; |
| } |
| |
| static void |
| drm_bridge_atomic_destroy_priv_state(struct drm_private_obj *obj, |
| struct drm_private_state *s) |
| { |
| struct drm_bridge_state *state = drm_priv_to_bridge_state(s); |
| struct drm_bridge *bridge = drm_priv_to_bridge(obj); |
| |
| bridge->funcs->atomic_destroy_state(bridge, state); |
| } |
| |
| static const struct drm_private_state_funcs drm_bridge_priv_state_funcs = { |
| .atomic_duplicate_state = drm_bridge_atomic_duplicate_priv_state, |
| .atomic_destroy_state = drm_bridge_atomic_destroy_priv_state, |
| }; |
| |
| /** |
| * drm_bridge_attach - attach the bridge to an encoder's chain |
| * |
| * @encoder: DRM encoder |
| * @bridge: bridge to attach |
| * @previous: previous bridge in the chain (optional) |
| * @flags: DRM_BRIDGE_ATTACH_* flags |
| * |
| * Called by a kms driver to link the bridge to an encoder's chain. The previous |
| * argument specifies the previous bridge in the chain. If NULL, the bridge is |
| * linked directly at the encoder's output. Otherwise it is linked at the |
| * previous bridge's output. |
| * |
| * If non-NULL the previous bridge must be already attached by a call to this |
| * function. |
| * |
| * Note that bridges attached to encoders are auto-detached during encoder |
| * cleanup in drm_encoder_cleanup(), so drm_bridge_attach() should generally |
| * *not* be balanced with a drm_bridge_detach() in driver code. |
| * |
| * RETURNS: |
| * Zero on success, error code on failure |
| */ |
| int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge, |
| struct drm_bridge *previous, |
| enum drm_bridge_attach_flags flags) |
| { |
| int ret; |
| |
| if (!encoder || !bridge) |
| return -EINVAL; |
| |
| if (previous && (!previous->dev || previous->encoder != encoder)) |
| return -EINVAL; |
| |
| if (bridge->dev) |
| return -EBUSY; |
| |
| bridge->dev = encoder->dev; |
| bridge->encoder = encoder; |
| |
| if (previous) |
| list_add(&bridge->chain_node, &previous->chain_node); |
| else |
| list_add(&bridge->chain_node, &encoder->bridge_chain); |
| |
| if (bridge->funcs->attach) { |
| ret = bridge->funcs->attach(bridge, flags); |
| if (ret < 0) |
| goto err_reset_bridge; |
| } |
| |
| if (bridge->funcs->atomic_reset) { |
| struct drm_bridge_state *state; |
| |
| state = bridge->funcs->atomic_reset(bridge); |
| if (IS_ERR(state)) { |
| ret = PTR_ERR(state); |
| goto err_detach_bridge; |
| } |
| |
| drm_atomic_private_obj_init(bridge->dev, &bridge->base, |
| &state->base, |
| &drm_bridge_priv_state_funcs); |
| } |
| |
| return 0; |
| |
| err_detach_bridge: |
| if (bridge->funcs->detach) |
| bridge->funcs->detach(bridge); |
| |
| err_reset_bridge: |
| bridge->dev = NULL; |
| bridge->encoder = NULL; |
| list_del(&bridge->chain_node); |
| |
| #ifdef CONFIG_OF |
| DRM_ERROR("failed to attach bridge %pOF to encoder %s: %d\n", |
| bridge->of_node, encoder->name, ret); |
| #else |
| DRM_ERROR("failed to attach bridge to encoder %s: %d\n", |
| encoder->name, ret); |
| #endif |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(drm_bridge_attach); |
| |
| void drm_bridge_detach(struct drm_bridge *bridge) |
| { |
| if (WARN_ON(!bridge)) |
| return; |
| |
| if (WARN_ON(!bridge->dev)) |
| return; |
| |
| if (bridge->funcs->atomic_reset) |
| drm_atomic_private_obj_fini(&bridge->base); |
| |
| if (bridge->funcs->detach) |
| bridge->funcs->detach(bridge); |
| |
| list_del(&bridge->chain_node); |
| bridge->dev = NULL; |
| } |
| |
| /** |
| * DOC: bridge operations |
| * |
| * Bridge drivers expose operations through the &drm_bridge_funcs structure. |
| * The DRM internals (atomic and CRTC helpers) use the helpers defined in |
| * drm_bridge.c to call bridge operations. Those operations are divided in |
| * three big categories to support different parts of the bridge usage. |
| * |
| * - The encoder-related operations support control of the bridges in the |
| * chain, and are roughly counterparts to the &drm_encoder_helper_funcs |
| * operations. They are used by the legacy CRTC and the atomic modeset |
| * helpers to perform mode validation, fixup and setting, and enable and |
| * disable the bridge automatically. |
| * |
| * The enable and disable operations are split in |
| * &drm_bridge_funcs.pre_enable, &drm_bridge_funcs.enable, |
| * &drm_bridge_funcs.disable and &drm_bridge_funcs.post_disable to provide |
| * finer-grained control. |
| * |
| * Bridge drivers may implement the legacy version of those operations, or |
| * the atomic version (prefixed with atomic\_), in which case they shall also |
| * implement the atomic state bookkeeping operations |
| * (&drm_bridge_funcs.atomic_duplicate_state, |
| * &drm_bridge_funcs.atomic_destroy_state and &drm_bridge_funcs.reset). |
| * Mixing atomic and non-atomic versions of the operations is not supported. |
| * |
| * - The bus format negotiation operations |
| * &drm_bridge_funcs.atomic_get_output_bus_fmts and |
| * &drm_bridge_funcs.atomic_get_input_bus_fmts allow bridge drivers to |
| * negotiate the formats transmitted between bridges in the chain when |
| * multiple formats are supported. Negotiation for formats is performed |
| * transparently for display drivers by the atomic modeset helpers. Only |
| * atomic versions of those operations exist, bridge drivers that need to |
| * implement them shall thus also implement the atomic version of the |
| * encoder-related operations. This feature is not supported by the legacy |
| * CRTC helpers. |
| * |
| * - The connector-related operations support implementing a &drm_connector |
| * based on a chain of bridges. DRM bridges traditionally create a |
| * &drm_connector for bridges meant to be used at the end of the chain. This |
| * puts additional burden on bridge drivers, especially for bridges that may |
| * be used in the middle of a chain or at the end of it. Furthermore, it |
| * requires all operations of the &drm_connector to be handled by a single |
| * bridge, which doesn't always match the hardware architecture. |
| * |
| * To simplify bridge drivers and make the connector implementation more |
| * flexible, a new model allows bridges to unconditionally skip creation of |
| * &drm_connector and instead expose &drm_bridge_funcs operations to support |
| * an externally-implemented &drm_connector. Those operations are |
| * &drm_bridge_funcs.detect, &drm_bridge_funcs.get_modes, |
| * &drm_bridge_funcs.get_edid, &drm_bridge_funcs.hpd_notify, |
| * &drm_bridge_funcs.hpd_enable and &drm_bridge_funcs.hpd_disable. When |
| * implemented, display drivers shall create a &drm_connector instance for |
| * each chain of bridges, and implement those connector instances based on |
| * the bridge connector operations. |
| * |
| * Bridge drivers shall implement the connector-related operations for all |
| * the features that the bridge hardware support. For instance, if a bridge |
| * supports reading EDID, the &drm_bridge_funcs.get_edid shall be |
| * implemented. This however doesn't mean that the DDC lines are wired to the |
| * bridge on a particular platform, as they could also be connected to an I2C |
| * controller of the SoC. Support for the connector-related operations on the |
| * running platform is reported through the &drm_bridge.ops flags. Bridge |
| * drivers shall detect which operations they can support on the platform |
| * (usually this information is provided by ACPI or DT), and set the |
| * &drm_bridge.ops flags for all supported operations. A flag shall only be |
| * set if the corresponding &drm_bridge_funcs operation is implemented, but |
| * an implemented operation doesn't necessarily imply that the corresponding |
| * flag will be set. Display drivers shall use the &drm_bridge.ops flags to |
| * decide which bridge to delegate a connector operation to. This mechanism |
| * allows providing a single static const &drm_bridge_funcs instance in |
| * bridge drivers, improving security by storing function pointers in |
| * read-only memory. |
| * |
| * In order to ease transition, bridge drivers may support both the old and |
| * new models by making connector creation optional and implementing the |
| * connected-related bridge operations. Connector creation is then controlled |
| * by the flags argument to the drm_bridge_attach() function. Display drivers |
| * that support the new model and create connectors themselves shall set the |
| * %DRM_BRIDGE_ATTACH_NO_CONNECTOR flag, and bridge drivers shall then skip |
| * connector creation. For intermediate bridges in the chain, the flag shall |
| * be passed to the drm_bridge_attach() call for the downstream bridge. |
| * Bridge drivers that implement the new model only shall return an error |
| * from their &drm_bridge_funcs.attach handler when the |
| * %DRM_BRIDGE_ATTACH_NO_CONNECTOR flag is not set. New display drivers |
| * should use the new model, and convert the bridge drivers they use if |
| * needed, in order to gradually transition to the new model. |
| */ |
| |
| /** |
| * drm_bridge_chain_mode_fixup - fixup proposed mode for all bridges in the |
| * encoder chain |
| * @bridge: bridge control structure |
| * @mode: desired mode to be set for the bridge |
| * @adjusted_mode: updated mode that works for this bridge |
| * |
| * Calls &drm_bridge_funcs.mode_fixup for all the bridges in the |
| * encoder chain, starting from the first bridge to the last. |
| * |
| * Note: the bridge passed should be the one closest to the encoder |
| * |
| * RETURNS: |
| * true on success, false on failure |
| */ |
| bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge, |
| const struct drm_display_mode *mode, |
| struct drm_display_mode *adjusted_mode) |
| { |
| struct drm_encoder *encoder; |
| |
| if (!bridge) |
| return true; |
| |
| encoder = bridge->encoder; |
| list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { |
| if (!bridge->funcs->mode_fixup) |
| continue; |
| |
| if (!bridge->funcs->mode_fixup(bridge, mode, adjusted_mode)) |
| return false; |
| } |
| |
| return true; |
| } |
| EXPORT_SYMBOL(drm_bridge_chain_mode_fixup); |
| |
| /** |
| * drm_bridge_chain_mode_valid - validate the mode against all bridges in the |
| * encoder chain. |
| * @bridge: bridge control structure |
| * @info: display info against which the mode shall be validated |
| * @mode: desired mode to be validated |
| * |
| * Calls &drm_bridge_funcs.mode_valid for all the bridges in the encoder |
| * chain, starting from the first bridge to the last. If at least one bridge |
| * does not accept the mode the function returns the error code. |
| * |
| * Note: the bridge passed should be the one closest to the encoder. |
| * |
| * RETURNS: |
| * MODE_OK on success, drm_mode_status Enum error code on failure |
| */ |
| enum drm_mode_status |
| drm_bridge_chain_mode_valid(struct drm_bridge *bridge, |
| const struct drm_display_info *info, |
| const struct drm_display_mode *mode) |
| { |
| struct drm_encoder *encoder; |
| |
| if (!bridge) |
| return MODE_OK; |
| |
| encoder = bridge->encoder; |
| list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { |
| enum drm_mode_status ret; |
| |
| if (!bridge->funcs->mode_valid) |
| continue; |
| |
| ret = bridge->funcs->mode_valid(bridge, info, mode); |
| if (ret != MODE_OK) |
| return ret; |
| } |
| |
| return MODE_OK; |
| } |
| EXPORT_SYMBOL(drm_bridge_chain_mode_valid); |
| |
| /** |
| * drm_bridge_chain_disable - disables all bridges in the encoder chain |
| * @bridge: bridge control structure |
| * |
| * Calls &drm_bridge_funcs.disable op for all the bridges in the encoder |
| * chain, starting from the last bridge to the first. These are called before |
| * calling the encoder's prepare op. |
| * |
| * Note: the bridge passed should be the one closest to the encoder |
| */ |
| void drm_bridge_chain_disable(struct drm_bridge *bridge) |
| { |
| struct drm_encoder *encoder; |
| struct drm_bridge *iter; |
| |
| if (!bridge) |
| return; |
| |
| encoder = bridge->encoder; |
| list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) { |
| if (iter->funcs->disable) |
| iter->funcs->disable(iter); |
| |
| if (iter == bridge) |
| break; |
| } |
| } |
| EXPORT_SYMBOL(drm_bridge_chain_disable); |
| |
| /** |
| * drm_bridge_chain_post_disable - cleans up after disabling all bridges in the |
| * encoder chain |
| * @bridge: bridge control structure |
| * |
| * Calls &drm_bridge_funcs.post_disable op for all the bridges in the |
| * encoder chain, starting from the first bridge to the last. These are called |
| * after completing the encoder's prepare op. |
| * |
| * Note: the bridge passed should be the one closest to the encoder |
| */ |
| void drm_bridge_chain_post_disable(struct drm_bridge *bridge) |
| { |
| struct drm_encoder *encoder; |
| |
| if (!bridge) |
| return; |
| |
| encoder = bridge->encoder; |
| list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { |
| if (bridge->funcs->post_disable) |
| bridge->funcs->post_disable(bridge); |
| } |
| } |
| EXPORT_SYMBOL(drm_bridge_chain_post_disable); |
| |
| /** |
| * drm_bridge_chain_mode_set - set proposed mode for all bridges in the |
| * encoder chain |
| * @bridge: bridge control structure |
| * @mode: desired mode to be set for the encoder chain |
| * @adjusted_mode: updated mode that works for this encoder chain |
| * |
| * Calls &drm_bridge_funcs.mode_set op for all the bridges in the |
| * encoder chain, starting from the first bridge to the last. |
| * |
| * Note: the bridge passed should be the one closest to the encoder |
| */ |
| void drm_bridge_chain_mode_set(struct drm_bridge *bridge, |
| const struct drm_display_mode *mode, |
| const struct drm_display_mode *adjusted_mode) |
| { |
| struct drm_encoder *encoder; |
| |
| if (!bridge) |
| return; |
| |
| encoder = bridge->encoder; |
| list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { |
| if (bridge->funcs->mode_set) |
| bridge->funcs->mode_set(bridge, mode, adjusted_mode); |
| } |
| } |
| EXPORT_SYMBOL(drm_bridge_chain_mode_set); |
| |
| /** |
| * drm_bridge_chain_pre_enable - prepares for enabling all bridges in the |
| * encoder chain |
| * @bridge: bridge control structure |
| * |
| * Calls &drm_bridge_funcs.pre_enable op for all the bridges in the encoder |
| * chain, starting from the last bridge to the first. These are called |
| * before calling the encoder's commit op. |
| * |
| * Note: the bridge passed should be the one closest to the encoder |
| */ |
| void drm_bridge_chain_pre_enable(struct drm_bridge *bridge) |
| { |
| struct drm_encoder *encoder; |
| struct drm_bridge *iter; |
| |
| if (!bridge) |
| return; |
| |
| encoder = bridge->encoder; |
| list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) { |
| if (iter->funcs->pre_enable) |
| iter->funcs->pre_enable(iter); |
| |
| if (iter == bridge) |
| break; |
| } |
| } |
| EXPORT_SYMBOL(drm_bridge_chain_pre_enable); |
| |
| /** |
| * drm_bridge_chain_enable - enables all bridges in the encoder chain |
| * @bridge: bridge control structure |
| * |
| * Calls &drm_bridge_funcs.enable op for all the bridges in the encoder |
| * chain, starting from the first bridge to the last. These are called |
| * after completing the encoder's commit op. |
| * |
| * Note that the bridge passed should be the one closest to the encoder |
| */ |
| void drm_bridge_chain_enable(struct drm_bridge *bridge) |
| { |
| struct drm_encoder *encoder; |
| |
| if (!bridge) |
| return; |
| |
| encoder = bridge->encoder; |
| list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { |
| if (bridge->funcs->enable) |
| bridge->funcs->enable(bridge); |
| } |
| } |
| EXPORT_SYMBOL(drm_bridge_chain_enable); |
| |
| /** |
| * drm_atomic_bridge_chain_disable - disables all bridges in the encoder chain |
| * @bridge: bridge control structure |
| * @old_state: old atomic state |
| * |
| * Calls &drm_bridge_funcs.atomic_disable (falls back on |
| * &drm_bridge_funcs.disable) op for all the bridges in the encoder chain, |
| * starting from the last bridge to the first. These are called before calling |
| * &drm_encoder_helper_funcs.atomic_disable |
| * |
| * Note: the bridge passed should be the one closest to the encoder |
| */ |
| void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge, |
| struct drm_atomic_state *old_state) |
| { |
| struct drm_encoder *encoder; |
| struct drm_bridge *iter; |
| |
| if (!bridge) |
| return; |
| |
| encoder = bridge->encoder; |
| list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) { |
| if (iter->funcs->atomic_disable) { |
| struct drm_bridge_state *old_bridge_state; |
| |
| old_bridge_state = |
| drm_atomic_get_old_bridge_state(old_state, |
| iter); |
| if (WARN_ON(!old_bridge_state)) |
| return; |
| |
| iter->funcs->atomic_disable(iter, old_bridge_state); |
| } else if (iter->funcs->disable) { |
| iter->funcs->disable(iter); |
| } |
| |
| if (iter == bridge) |
| break; |
| } |
| } |
| EXPORT_SYMBOL(drm_atomic_bridge_chain_disable); |
| |
| /** |
| * drm_atomic_bridge_chain_post_disable - cleans up after disabling all bridges |
| * in the encoder chain |
| * @bridge: bridge control structure |
| * @old_state: old atomic state |
| * |
| * Calls &drm_bridge_funcs.atomic_post_disable (falls back on |
| * &drm_bridge_funcs.post_disable) op for all the bridges in the encoder chain, |
| * starting from the first bridge to the last. These are called after completing |
| * &drm_encoder_helper_funcs.atomic_disable |
| * |
| * Note: the bridge passed should be the one closest to the encoder |
| */ |
| void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge, |
| struct drm_atomic_state *old_state) |
| { |
| struct drm_encoder *encoder; |
| |
| if (!bridge) |
| return; |
| |
| encoder = bridge->encoder; |
| list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { |
| if (bridge->funcs->atomic_post_disable) { |
| struct drm_bridge_state *old_bridge_state; |
| |
| old_bridge_state = |
| drm_atomic_get_old_bridge_state(old_state, |
| bridge); |
| if (WARN_ON(!old_bridge_state)) |
| return; |
| |
| bridge->funcs->atomic_post_disable(bridge, |
| old_bridge_state); |
| } else if (bridge->funcs->post_disable) { |
| bridge->funcs->post_disable(bridge); |
| } |
| } |
| } |
| EXPORT_SYMBOL(drm_atomic_bridge_chain_post_disable); |
| |
| /** |
| * drm_atomic_bridge_chain_pre_enable - prepares for enabling all bridges in |
| * the encoder chain |
| * @bridge: bridge control structure |
| * @old_state: old atomic state |
| * |
| * Calls &drm_bridge_funcs.atomic_pre_enable (falls back on |
| * &drm_bridge_funcs.pre_enable) op for all the bridges in the encoder chain, |
| * starting from the last bridge to the first. These are called before calling |
| * &drm_encoder_helper_funcs.atomic_enable |
| * |
| * Note: the bridge passed should be the one closest to the encoder |
| */ |
| void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge, |
| struct drm_atomic_state *old_state) |
| { |
| struct drm_encoder *encoder; |
| struct drm_bridge *iter; |
| |
| if (!bridge) |
| return; |
| |
| encoder = bridge->encoder; |
| list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) { |
| if (iter->funcs->atomic_pre_enable) { |
| struct drm_bridge_state *old_bridge_state; |
| |
| old_bridge_state = |
| drm_atomic_get_old_bridge_state(old_state, |
| iter); |
| if (WARN_ON(!old_bridge_state)) |
| return; |
| |
| iter->funcs->atomic_pre_enable(iter, old_bridge_state); |
| } else if (iter->funcs->pre_enable) { |
| iter->funcs->pre_enable(iter); |
| } |
| |
| if (iter == bridge) |
| break; |
| } |
| } |
| EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable); |
| |
| /** |
| * drm_atomic_bridge_chain_enable - enables all bridges in the encoder chain |
| * @bridge: bridge control structure |
| * @old_state: old atomic state |
| * |
| * Calls &drm_bridge_funcs.atomic_enable (falls back on |
| * &drm_bridge_funcs.enable) op for all the bridges in the encoder chain, |
| * starting from the first bridge to the last. These are called after completing |
| * &drm_encoder_helper_funcs.atomic_enable |
| * |
| * Note: the bridge passed should be the one closest to the encoder |
| */ |
| void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge, |
| struct drm_atomic_state *old_state) |
| { |
| struct drm_encoder *encoder; |
| |
| if (!bridge) |
| return; |
| |
| encoder = bridge->encoder; |
| list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { |
| if (bridge->funcs->atomic_enable) { |
| struct drm_bridge_state *old_bridge_state; |
| |
| old_bridge_state = |
| drm_atomic_get_old_bridge_state(old_state, |
| bridge); |
| if (WARN_ON(!old_bridge_state)) |
| return; |
| |
| bridge->funcs->atomic_enable(bridge, old_bridge_state); |
| } else if (bridge->funcs->enable) { |
| bridge->funcs->enable(bridge); |
| } |
| } |
| } |
| EXPORT_SYMBOL(drm_atomic_bridge_chain_enable); |
| |
| static int drm_atomic_bridge_check(struct drm_bridge *bridge, |
| struct drm_crtc_state *crtc_state, |
| struct drm_connector_state *conn_state) |
| { |
| if (bridge->funcs->atomic_check) { |
| struct drm_bridge_state *bridge_state; |
| int ret; |
| |
| bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state, |
| bridge); |
| if (WARN_ON(!bridge_state)) |
| return -EINVAL; |
| |
| ret = bridge->funcs->atomic_check(bridge, bridge_state, |
| crtc_state, conn_state); |
| if (ret) |
| return ret; |
| } else if (bridge->funcs->mode_fixup) { |
| if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode, |
| &crtc_state->adjusted_mode)) |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int select_bus_fmt_recursive(struct drm_bridge *first_bridge, |
| struct drm_bridge *cur_bridge, |
| struct drm_crtc_state *crtc_state, |
| struct drm_connector_state *conn_state, |
| u32 out_bus_fmt) |
| { |
| struct drm_bridge_state *cur_state; |
| unsigned int num_in_bus_fmts, i; |
| struct drm_bridge *prev_bridge; |
| u32 *in_bus_fmts; |
| int ret; |
| |
| prev_bridge = drm_bridge_get_prev_bridge(cur_bridge); |
| cur_state = drm_atomic_get_new_bridge_state(crtc_state->state, |
| cur_bridge); |
| |
| /* |
| * If bus format negotiation is not supported by this bridge, let's |
| * pass MEDIA_BUS_FMT_FIXED to the previous bridge in the chain and |
| * hope that it can handle this situation gracefully (by providing |
| * appropriate default values). |
| */ |
| if (!cur_bridge->funcs->atomic_get_input_bus_fmts) { |
| if (cur_bridge != first_bridge) { |
| ret = select_bus_fmt_recursive(first_bridge, |
| prev_bridge, crtc_state, |
| conn_state, |
| MEDIA_BUS_FMT_FIXED); |
| if (ret) |
| return ret; |
| } |
| |
| /* |
| * Driver does not implement the atomic state hooks, but that's |
| * fine, as long as it does not access the bridge state. |
| */ |
| if (cur_state) { |
| cur_state->input_bus_cfg.format = MEDIA_BUS_FMT_FIXED; |
| cur_state->output_bus_cfg.format = out_bus_fmt; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * If the driver implements ->atomic_get_input_bus_fmts() it |
| * should also implement the atomic state hooks. |
| */ |
| if (WARN_ON(!cur_state)) |
| return -EINVAL; |
| |
| in_bus_fmts = cur_bridge->funcs->atomic_get_input_bus_fmts(cur_bridge, |
| cur_state, |
| crtc_state, |
| conn_state, |
| out_bus_fmt, |
| &num_in_bus_fmts); |
| if (!num_in_bus_fmts) |
| return -ENOTSUPP; |
| else if (!in_bus_fmts) |
| return -ENOMEM; |
| |
| if (first_bridge == cur_bridge) { |
| cur_state->input_bus_cfg.format = in_bus_fmts[0]; |
| cur_state->output_bus_cfg.format = out_bus_fmt; |
| kfree(in_bus_fmts); |
| return 0; |
| } |
| |
| for (i = 0; i < num_in_bus_fmts; i++) { |
| ret = select_bus_fmt_recursive(first_bridge, prev_bridge, |
| crtc_state, conn_state, |
| in_bus_fmts[i]); |
| if (ret != -ENOTSUPP) |
| break; |
| } |
| |
| if (!ret) { |
| cur_state->input_bus_cfg.format = in_bus_fmts[i]; |
| cur_state->output_bus_cfg.format = out_bus_fmt; |
| } |
| |
| kfree(in_bus_fmts); |
| return ret; |
| } |
| |
| /* |
| * This function is called by &drm_atomic_bridge_chain_check() just before |
| * calling &drm_bridge_funcs.atomic_check() on all elements of the chain. |
| * It performs bus format negotiation between bridge elements. The negotiation |
| * happens in reverse order, starting from the last element in the chain up to |
| * @bridge. |
| * |
| * Negotiation starts by retrieving supported output bus formats on the last |
| * bridge element and testing them one by one. The test is recursive, meaning |
| * that for each tested output format, the whole chain will be walked backward, |
| * and each element will have to choose an input bus format that can be |
| * transcoded to the requested output format. When a bridge element does not |
| * support transcoding into a specific output format -ENOTSUPP is returned and |
| * the next bridge element will have to try a different format. If none of the |
| * combinations worked, -ENOTSUPP is returned and the atomic modeset will fail. |
| * |
| * This implementation is relying on |
| * &drm_bridge_funcs.atomic_get_output_bus_fmts() and |
| * &drm_bridge_funcs.atomic_get_input_bus_fmts() to gather supported |
| * input/output formats. |
| * |
| * When &drm_bridge_funcs.atomic_get_output_bus_fmts() is not implemented by |
| * the last element of the chain, &drm_atomic_bridge_chain_select_bus_fmts() |
| * tries a single format: &drm_connector.display_info.bus_formats[0] if |
| * available, MEDIA_BUS_FMT_FIXED otherwise. |
| * |
| * When &drm_bridge_funcs.atomic_get_input_bus_fmts() is not implemented, |
| * &drm_atomic_bridge_chain_select_bus_fmts() skips the negotiation on the |
| * bridge element that lacks this hook and asks the previous element in the |
| * chain to try MEDIA_BUS_FMT_FIXED. It's up to bridge drivers to decide what |
| * to do in that case (fail if they want to enforce bus format negotiation, or |
| * provide a reasonable default if they need to support pipelines where not |
| * all elements support bus format negotiation). |
| */ |
| static int |
| drm_atomic_bridge_chain_select_bus_fmts(struct drm_bridge *bridge, |
| struct drm_crtc_state *crtc_state, |
| struct drm_connector_state *conn_state) |
| { |
| struct drm_connector *conn = conn_state->connector; |
| struct drm_encoder *encoder = bridge->encoder; |
| struct drm_bridge_state *last_bridge_state; |
| unsigned int i, num_out_bus_fmts; |
| struct drm_bridge *last_bridge; |
| u32 *out_bus_fmts; |
| int ret = 0; |
| |
| last_bridge = list_last_entry(&encoder->bridge_chain, |
| struct drm_bridge, chain_node); |
| last_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state, |
| last_bridge); |
| |
| if (last_bridge->funcs->atomic_get_output_bus_fmts) { |
| const struct drm_bridge_funcs *funcs = last_bridge->funcs; |
| |
| /* |
| * If the driver implements ->atomic_get_output_bus_fmts() it |
| * should also implement the atomic state hooks. |
| */ |
| if (WARN_ON(!last_bridge_state)) |
| return -EINVAL; |
| |
| out_bus_fmts = funcs->atomic_get_output_bus_fmts(last_bridge, |
| last_bridge_state, |
| crtc_state, |
| conn_state, |
| &num_out_bus_fmts); |
| if (!num_out_bus_fmts) |
| return -ENOTSUPP; |
| else if (!out_bus_fmts) |
| return -ENOMEM; |
| } else { |
| num_out_bus_fmts = 1; |
| out_bus_fmts = kmalloc(sizeof(*out_bus_fmts), GFP_KERNEL); |
| if (!out_bus_fmts) |
| return -ENOMEM; |
| |
| if (conn->display_info.num_bus_formats && |
| conn->display_info.bus_formats) |
| out_bus_fmts[0] = conn->display_info.bus_formats[0]; |
| else |
| out_bus_fmts[0] = MEDIA_BUS_FMT_FIXED; |
| } |
| |
| for (i = 0; i < num_out_bus_fmts; i++) { |
| ret = select_bus_fmt_recursive(bridge, last_bridge, crtc_state, |
| conn_state, out_bus_fmts[i]); |
| if (ret != -ENOTSUPP) |
| break; |
| } |
| |
| kfree(out_bus_fmts); |
| |
| return ret; |
| } |
| |
| static void |
| drm_atomic_bridge_propagate_bus_flags(struct drm_bridge *bridge, |
| struct drm_connector *conn, |
| struct drm_atomic_state *state) |
| { |
| struct drm_bridge_state *bridge_state, *next_bridge_state; |
| struct drm_bridge *next_bridge; |
| u32 output_flags = 0; |
| |
| bridge_state = drm_atomic_get_new_bridge_state(state, bridge); |
| |
| /* No bridge state attached to this bridge => nothing to propagate. */ |
| if (!bridge_state) |
| return; |
| |
| next_bridge = drm_bridge_get_next_bridge(bridge); |
| |
| /* |
| * Let's try to apply the most common case here, that is, propagate |
| * display_info flags for the last bridge, and propagate the input |
| * flags of the next bridge element to the output end of the current |
| * bridge when the bridge is not the last one. |
| * There are exceptions to this rule, like when signal inversion is |
| * happening at the board level, but that's something drivers can deal |
| * with from their &drm_bridge_funcs.atomic_check() implementation by |
| * simply overriding the flags value we've set here. |
| */ |
| if (!next_bridge) { |
| output_flags = conn->display_info.bus_flags; |
| } else { |
| next_bridge_state = drm_atomic_get_new_bridge_state(state, |
| next_bridge); |
| /* |
| * No bridge state attached to the next bridge, just leave the |
| * flags to 0. |
| */ |
| if (next_bridge_state) |
| output_flags = next_bridge_state->input_bus_cfg.flags; |
| } |
| |
| bridge_state->output_bus_cfg.flags = output_flags; |
| |
| /* |
| * Propagate the output flags to the input end of the bridge. Again, it's |
| * not necessarily what all bridges want, but that's what most of them |
| * do, and by doing that by default we avoid forcing drivers to |
| * duplicate the "dummy propagation" logic. |
| */ |
| bridge_state->input_bus_cfg.flags = output_flags; |
| } |
| |
| /** |
| * drm_atomic_bridge_chain_check() - Do an atomic check on the bridge chain |
| * @bridge: bridge control structure |
| * @crtc_state: new CRTC state |
| * @conn_state: new connector state |
| * |
| * First trigger a bus format negotiation before calling |
| * &drm_bridge_funcs.atomic_check() (falls back on |
| * &drm_bridge_funcs.mode_fixup()) op for all the bridges in the encoder chain, |
| * starting from the last bridge to the first. These are called before calling |
| * &drm_encoder_helper_funcs.atomic_check() |
| * |
| * RETURNS: |
| * 0 on success, a negative error code on failure |
| */ |
| int drm_atomic_bridge_chain_check(struct drm_bridge *bridge, |
| struct drm_crtc_state *crtc_state, |
| struct drm_connector_state *conn_state) |
| { |
| struct drm_connector *conn = conn_state->connector; |
| struct drm_encoder *encoder; |
| struct drm_bridge *iter; |
| int ret; |
| |
| if (!bridge) |
| return 0; |
| |
| ret = drm_atomic_bridge_chain_select_bus_fmts(bridge, crtc_state, |
| conn_state); |
| if (ret) |
| return ret; |
| |
| encoder = bridge->encoder; |
| list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) { |
| int ret; |
| |
| /* |
| * Bus flags are propagated by default. If a bridge needs to |
| * tweak the input bus flags for any reason, it should happen |
| * in its &drm_bridge_funcs.atomic_check() implementation such |
| * that preceding bridges in the chain can propagate the new |
| * bus flags. |
| */ |
| drm_atomic_bridge_propagate_bus_flags(iter, conn, |
| crtc_state->state); |
| |
| ret = drm_atomic_bridge_check(iter, crtc_state, conn_state); |
| if (ret) |
| return ret; |
| |
| if (iter == bridge) |
| break; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_atomic_bridge_chain_check); |
| |
| /** |
| * drm_bridge_detect - check if anything is attached to the bridge output |
| * @bridge: bridge control structure |
| * |
| * If the bridge supports output detection, as reported by the |
| * DRM_BRIDGE_OP_DETECT bridge ops flag, call &drm_bridge_funcs.detect for the |
| * bridge and return the connection status. Otherwise return |
| * connector_status_unknown. |
| * |
| * RETURNS: |
| * The detection status on success, or connector_status_unknown if the bridge |
| * doesn't support output detection. |
| */ |
| enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge) |
| { |
| if (!(bridge->ops & DRM_BRIDGE_OP_DETECT)) |
| return connector_status_unknown; |
| |
| return bridge->funcs->detect(bridge); |
| } |
| EXPORT_SYMBOL_GPL(drm_bridge_detect); |
| |
| /** |
| * drm_bridge_get_modes - fill all modes currently valid for the sink into the |
| * @connector |
| * @bridge: bridge control structure |
| * @connector: the connector to fill with modes |
| * |
| * If the bridge supports output modes retrieval, as reported by the |
| * DRM_BRIDGE_OP_MODES bridge ops flag, call &drm_bridge_funcs.get_modes to |
| * fill the connector with all valid modes and return the number of modes |
| * added. Otherwise return 0. |
| * |
| * RETURNS: |
| * The number of modes added to the connector. |
| */ |
| int drm_bridge_get_modes(struct drm_bridge *bridge, |
| struct drm_connector *connector) |
| { |
| if (!(bridge->ops & DRM_BRIDGE_OP_MODES)) |
| return 0; |
| |
| return bridge->funcs->get_modes(bridge, connector); |
| } |
| EXPORT_SYMBOL_GPL(drm_bridge_get_modes); |
| |
| /** |
| * drm_bridge_get_edid - get the EDID data of the connected display |
| * @bridge: bridge control structure |
| * @connector: the connector to read EDID for |
| * |
| * If the bridge supports output EDID retrieval, as reported by the |
| * DRM_BRIDGE_OP_EDID bridge ops flag, call &drm_bridge_funcs.get_edid to |
| * get the EDID and return it. Otherwise return NULL. |
| * |
| * RETURNS: |
| * The retrieved EDID on success, or NULL otherwise. |
| */ |
| struct edid *drm_bridge_get_edid(struct drm_bridge *bridge, |
| struct drm_connector *connector) |
| { |
| if (!(bridge->ops & DRM_BRIDGE_OP_EDID)) |
| return NULL; |
| |
| return bridge->funcs->get_edid(bridge, connector); |
| } |
| EXPORT_SYMBOL_GPL(drm_bridge_get_edid); |
| |
| /** |
| * drm_bridge_hpd_enable - enable hot plug detection for the bridge |
| * @bridge: bridge control structure |
| * @cb: hot-plug detection callback |
| * @data: data to be passed to the hot-plug detection callback |
| * |
| * Call &drm_bridge_funcs.hpd_enable if implemented and register the given @cb |
| * and @data as hot plug notification callback. From now on the @cb will be |
| * called with @data when an output status change is detected by the bridge, |
| * until hot plug notification gets disabled with drm_bridge_hpd_disable(). |
| * |
| * Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in |
| * bridge->ops. This function shall not be called when the flag is not set. |
| * |
| * Only one hot plug detection callback can be registered at a time, it is an |
| * error to call this function when hot plug detection is already enabled for |
| * the bridge. |
| */ |
| void drm_bridge_hpd_enable(struct drm_bridge *bridge, |
| void (*cb)(void *data, |
| enum drm_connector_status status), |
| void *data) |
| { |
| if (!(bridge->ops & DRM_BRIDGE_OP_HPD)) |
| return; |
| |
| mutex_lock(&bridge->hpd_mutex); |
| |
| if (WARN(bridge->hpd_cb, "Hot plug detection already enabled\n")) |
| goto unlock; |
| |
| bridge->hpd_cb = cb; |
| bridge->hpd_data = data; |
| |
| if (bridge->funcs->hpd_enable) |
| bridge->funcs->hpd_enable(bridge); |
| |
| unlock: |
| mutex_unlock(&bridge->hpd_mutex); |
| } |
| EXPORT_SYMBOL_GPL(drm_bridge_hpd_enable); |
| |
| /** |
| * drm_bridge_hpd_disable - disable hot plug detection for the bridge |
| * @bridge: bridge control structure |
| * |
| * Call &drm_bridge_funcs.hpd_disable if implemented and unregister the hot |
| * plug detection callback previously registered with drm_bridge_hpd_enable(). |
| * Once this function returns the callback will not be called by the bridge |
| * when an output status change occurs. |
| * |
| * Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in |
| * bridge->ops. This function shall not be called when the flag is not set. |
| */ |
| void drm_bridge_hpd_disable(struct drm_bridge *bridge) |
| { |
| if (!(bridge->ops & DRM_BRIDGE_OP_HPD)) |
| return; |
| |
| mutex_lock(&bridge->hpd_mutex); |
| if (bridge->funcs->hpd_disable) |
| bridge->funcs->hpd_disable(bridge); |
| |
| bridge->hpd_cb = NULL; |
| bridge->hpd_data = NULL; |
| mutex_unlock(&bridge->hpd_mutex); |
| } |
| EXPORT_SYMBOL_GPL(drm_bridge_hpd_disable); |
| |
| /** |
| * drm_bridge_hpd_notify - notify hot plug detection events |
| * @bridge: bridge control structure |
| * @status: output connection status |
| * |
| * Bridge drivers shall call this function to report hot plug events when they |
| * detect a change in the output status, when hot plug detection has been |
| * enabled by drm_bridge_hpd_enable(). |
| * |
| * This function shall be called in a context that can sleep. |
| */ |
| void drm_bridge_hpd_notify(struct drm_bridge *bridge, |
| enum drm_connector_status status) |
| { |
| mutex_lock(&bridge->hpd_mutex); |
| if (bridge->hpd_cb) |
| bridge->hpd_cb(bridge->hpd_data, status); |
| mutex_unlock(&bridge->hpd_mutex); |
| } |
| EXPORT_SYMBOL_GPL(drm_bridge_hpd_notify); |
| |
| #ifdef CONFIG_OF |
| /** |
| * of_drm_find_bridge - find the bridge corresponding to the device node in |
| * the global bridge list |
| * |
| * @np: device node |
| * |
| * RETURNS: |
| * drm_bridge control struct on success, NULL on failure |
| */ |
| struct drm_bridge *of_drm_find_bridge(struct device_node *np) |
| { |
| struct drm_bridge *bridge; |
| |
| mutex_lock(&bridge_lock); |
| |
| list_for_each_entry(bridge, &bridge_list, list) { |
| if (bridge->of_node == np) { |
| mutex_unlock(&bridge_lock); |
| return bridge; |
| } |
| } |
| |
| mutex_unlock(&bridge_lock); |
| return NULL; |
| } |
| EXPORT_SYMBOL(of_drm_find_bridge); |
| #endif |
| |
| MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>"); |
| MODULE_DESCRIPTION("DRM bridge infrastructure"); |
| MODULE_LICENSE("GPL and additional rights"); |