| /* |
| * 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 <drm/drm_crtc.h> |
| |
| #include "drm/drmP.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 next pointer in struct &drm_bridge. |
| * |
| * 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 |
| * |
| * RETURNS: |
| * Unconditionally returns Zero. |
| */ |
| int drm_bridge_add(struct drm_bridge *bridge) |
| { |
| mutex_lock(&bridge_lock); |
| list_add_tail(&bridge->list, &bridge_list); |
| mutex_unlock(&bridge_lock); |
| |
| return 0; |
| } |
| 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 - associate given bridge to our DRM device |
| * |
| * @dev: DRM device |
| * @bridge: bridge control structure |
| * |
| * called by a kms driver to link one of our encoder/bridge to the given |
| * bridge. |
| * |
| * Note that setting up links between the bridge and our encoder/bridge |
| * objects needs to be handled by the kms driver itself |
| * |
| * RETURNS: |
| * Zero on success, error code on failure |
| */ |
| int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge) |
| { |
| if (!dev || !bridge) |
| return -EINVAL; |
| |
| if (bridge->dev) |
| return -EBUSY; |
| |
| bridge->dev = dev; |
| |
| if (bridge->funcs->attach) |
| return bridge->funcs->attach(bridge); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_bridge_attach); |
| |
| /** |
| * 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 ->mode_fixup() &drm_bridge_funcs 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 |
| * |
| * 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_disable - calls ->disable() &drm_bridge_funcs op for all |
| * bridges in the encoder chain. |
| * @bridge: bridge control structure |
| * |
| * Calls ->disable() &drm_bridge_funcs 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 - calls ->post_disable() &drm_bridge_funcs op for |
| * all bridges in the encoder chain. |
| * @bridge: bridge control structure |
| * |
| * Calls ->post_disable() &drm_bridge_funcs 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 ->mode_set() &drm_bridge_funcs 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, |
| struct drm_display_mode *mode, |
| 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 - calls ->pre_enable() &drm_bridge_funcs op for all |
| * bridges in the encoder chain. |
| * @bridge: bridge control structure |
| * |
| * Calls ->pre_enable() &drm_bridge_funcs 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 - calls ->enable() &drm_bridge_funcs op for all bridges |
| * in the encoder chain. |
| * @bridge: bridge control structure |
| * |
| * Calls ->enable() &drm_bridge_funcs 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); |
| |
| #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"); |