drivers/gpu/drm/drm_bridge.c

   1 /*
   2  * Copyright (c) 2014 Samsung Electronics Co., Ltd
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sub license,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the
  12  * next paragraph) shall be included in all copies or substantial portions
  13  * of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 #include <linux/err.h>
  25 #include <linux/module.h>
  26
  27 #include <drm/drm_crtc.h>
  28
  29 #include "drm/drmP.h"
  30
  31 static DEFINE_MUTEX(bridge_lock);
  32 static LIST_HEAD(bridge_list);
  33
  34 int drm_bridge_add(struct drm_bridge *bridge)
  35 {
  36         mutex_lock(&bridge_lock);
  37         list_add_tail(&bridge->list, &bridge_list);
  38         mutex_unlock(&bridge_lock);
  39
  40         return 0;
  41 }
  42 EXPORT_SYMBOL(drm_bridge_add);
  43
  44 void drm_bridge_remove(struct drm_bridge *bridge)
  45 {
  46         mutex_lock(&bridge_lock);
  47         list_del_init(&bridge->list);
  48         mutex_unlock(&bridge_lock);
  49 }
  50 EXPORT_SYMBOL(drm_bridge_remove);
  51
  52 extern int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge)
  53 {
  54         if (!dev || !bridge)
  55                 return -EINVAL;
  56
  57         if (bridge->dev)
  58                 return -EBUSY;
  59
  60         bridge->dev = dev;
  61
  62         if (bridge->funcs->attach)
  63                 return bridge->funcs->attach(bridge);
  64
  65         return 0;
  66 }
  67 EXPORT_SYMBOL(drm_bridge_attach);
  68
  69 #ifdef CONFIG_OF
  70 struct drm_bridge *of_drm_find_bridge(struct device_node *np)
  71 {
  72         struct drm_bridge *bridge;
  73
  74         mutex_lock(&bridge_lock);
  75
  76         list_for_each_entry(bridge, &bridge_list, list) {
  77                 if (bridge->of_node == np) {
  78                         mutex_unlock(&bridge_lock);
  79                         return bridge;
  80                 }
  81         }
  82
  83         mutex_unlock(&bridge_lock);
  84         return NULL;
  85 }
  86 EXPORT_SYMBOL(of_drm_find_bridge);
  87 #endif
  88
  89 MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>");
  90 MODULE_DESCRIPTION("DRM bridge infrastructure");
  91 MODULE_LICENSE("GPL and additional rights");