| /* |
| * 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_bridge.h> |
| #include <drm/drm_encoder.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 an intermediate bridge:: |
| * |
| * encoder ---> bridge B ---> bridge A |
| * |
| * Here, the output of the encoder feeds to bridge B, and that furthers feeds to |
| * bridge A. |
| * |
| * The driver using the bridge is responsible to make the associations between |
| * the encoder and bridges. Once these links are made, the bridges will |
| * participate along with encoder functions to perform mode_set/enable/disable |
| * through the ops provided in &drm_bridge_funcs. |
| * |
| * 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. |
| * |
| * Bridges can also be chained up using the &drm_bridge.next pointer. |
| * |
| * Both legacy CRTC helpers and the new atomic modeset helpers support bridges. |
| */ |
| |
| 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_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); |
| } |
| EXPORT_SYMBOL(drm_bridge_remove); |
| |
| /** |
| * 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) |
| * |
| * 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) |
| { |
| 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 (bridge->funcs->attach) { |
| ret = bridge->funcs->attach(bridge); |
| if (ret < 0) { |
| bridge->dev = NULL; |
| bridge->encoder = NULL; |
| return ret; |
| } |
| } |
| |
| if (previous) |
| previous->next = bridge; |
| else |
| encoder->bridge = bridge; |
| |
| return 0; |
| } |
| 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->detach) |
| bridge->funcs->detach(bridge); |
| |
| bridge->dev = NULL; |
| } |
| |
| /** |
| * DOC: bridge callbacks |
| * |
| * The &drm_bridge_funcs ops are populated by the bridge driver. The DRM |
| * internals (atomic and CRTC helpers) use the helpers defined in drm_bridge.c |
| * These helpers call a specific &drm_bridge_funcs op for all the bridges |
| * during encoder configuration. |
| * |
| * For detailed specification of the bridge callbacks see &drm_bridge_funcs. |
| */ |
| |
| /** |
| * drm_bridge_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_mode_fixup(struct drm_bridge *bridge, |
| const struct drm_display_mode *mode, |
| struct drm_display_mode *adjusted_mode) |
| { |
| bool ret = true; |
| |
| if (!bridge) |
| return true; |
| |
| if (bridge->funcs->mode_fixup) |
| ret = bridge->funcs->mode_fixup(bridge, mode, adjusted_mode); |
| |
| ret = ret && drm_bridge_mode_fixup(bridge->next, mode, adjusted_mode); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(drm_bridge_mode_fixup); |
| |
| /** |
| * drm_bridge_mode_valid - validate the mode against all bridges in the |
| * encoder chain. |
| * @bridge: bridge control structure |
| * @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_mode_valid(struct drm_bridge *bridge, |
| const struct drm_display_mode *mode) |
| { |
| enum drm_mode_status ret = MODE_OK; |
| |
| if (!bridge) |
| return ret; |
| |
| if (bridge->funcs->mode_valid) |
| ret = bridge->funcs->mode_valid(bridge, mode); |
| |
| if (ret != MODE_OK) |
| return ret; |
| |
| return drm_bridge_mode_valid(bridge->next, mode); |
| } |
| EXPORT_SYMBOL(drm_bridge_mode_valid); |
| |
| /** |
| * drm_bridge_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_disable(struct drm_bridge *bridge) |
| { |
| if (!bridge) |
| return; |
| |
| drm_bridge_disable(bridge->next); |
| |
| if (bridge->funcs->disable) |
| bridge->funcs->disable(bridge); |
| } |
| EXPORT_SYMBOL(drm_bridge_disable); |
| |
| /** |
| * drm_bridge_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_post_disable(struct drm_bridge *bridge) |
| { |
| if (!bridge) |
| return; |
| |
| if (bridge->funcs->post_disable) |
| bridge->funcs->post_disable(bridge); |
| |
| drm_bridge_post_disable(bridge->next); |
| } |
| EXPORT_SYMBOL(drm_bridge_post_disable); |
| |
| /** |
| * drm_bridge_mode_set - set 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_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_mode_set(struct drm_bridge *bridge, |
| const struct drm_display_mode *mode, |
| const struct drm_display_mode *adjusted_mode) |
| { |
| if (!bridge) |
| return; |
| |
| if (bridge->funcs->mode_set) |
| bridge->funcs->mode_set(bridge, mode, adjusted_mode); |
| |
| drm_bridge_mode_set(bridge->next, mode, adjusted_mode); |
| } |
| EXPORT_SYMBOL(drm_bridge_mode_set); |
| |
| /** |
| * drm_bridge_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_pre_enable(struct drm_bridge *bridge) |
| { |
| if (!bridge) |
| return; |
| |
| drm_bridge_pre_enable(bridge->next); |
| |
| if (bridge->funcs->pre_enable) |
| bridge->funcs->pre_enable(bridge); |
| } |
| EXPORT_SYMBOL(drm_bridge_pre_enable); |
| |
| /** |
| * drm_bridge_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_enable(struct drm_bridge *bridge) |
| { |
| if (!bridge) |
| return; |
| |
| if (bridge->funcs->enable) |
| bridge->funcs->enable(bridge); |
| |
| drm_bridge_enable(bridge->next); |
| } |
| EXPORT_SYMBOL(drm_bridge_enable); |
| |
| /** |
| * drm_atomic_bridge_disable - disables all bridges in the encoder chain |
| * @bridge: bridge control structure |
| * @state: atomic state being committed |
| * |
| * 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_disable(struct drm_bridge *bridge, |
| struct drm_atomic_state *state) |
| { |
| if (!bridge) |
| return; |
| |
| drm_atomic_bridge_disable(bridge->next, state); |
| |
| if (bridge->funcs->atomic_disable) |
| bridge->funcs->atomic_disable(bridge, state); |
| else if (bridge->funcs->disable) |
| bridge->funcs->disable(bridge); |
| } |
| EXPORT_SYMBOL(drm_atomic_bridge_disable); |
| |
| /** |
| * drm_atomic_bridge_post_disable - cleans up after disabling all bridges in the |
| * encoder chain |
| * @bridge: bridge control structure |
| * @state: atomic state being committed |
| * |
| * 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_post_disable(struct drm_bridge *bridge, |
| struct drm_atomic_state *state) |
| { |
| if (!bridge) |
| return; |
| |
| if (bridge->funcs->atomic_post_disable) |
| bridge->funcs->atomic_post_disable(bridge, state); |
| else if (bridge->funcs->post_disable) |
| bridge->funcs->post_disable(bridge); |
| |
| drm_atomic_bridge_post_disable(bridge->next, state); |
| } |
| EXPORT_SYMBOL(drm_atomic_bridge_post_disable); |
| |
| /** |
| * drm_atomic_bridge_pre_enable - prepares for enabling all bridges in the |
| * encoder chain |
| * @bridge: bridge control structure |
| * @state: atomic state being committed |
| * |
| * 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_pre_enable(struct drm_bridge *bridge, |
| struct drm_atomic_state *state) |
| { |
| if (!bridge) |
| return; |
| |
| drm_atomic_bridge_pre_enable(bridge->next, state); |
| |
| if (bridge->funcs->atomic_pre_enable) |
| bridge->funcs->atomic_pre_enable(bridge, state); |
| else if (bridge->funcs->pre_enable) |
| bridge->funcs->pre_enable(bridge); |
| } |
| EXPORT_SYMBOL(drm_atomic_bridge_pre_enable); |
| |
| /** |
| * drm_atomic_bridge_enable - enables all bridges in the encoder chain |
| * @bridge: bridge control structure |
| * @state: atomic state being committed |
| * |
| * 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_enable(struct drm_bridge *bridge, |
| struct drm_atomic_state *state) |
| { |
| if (!bridge) |
| return; |
| |
| if (bridge->funcs->atomic_enable) |
| bridge->funcs->atomic_enable(bridge, state); |
| else if (bridge->funcs->enable) |
| bridge->funcs->enable(bridge); |
| |
| drm_atomic_bridge_enable(bridge->next, state); |
| } |
| EXPORT_SYMBOL(drm_atomic_bridge_enable); |
| |
| #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"); |