blob: 3dfe3c886502d8b9abac5492075aded558f26b3e [file] [log] [blame]
Thierry Redingaead40e2013-08-30 13:36:43 +02001/*
2 * Copyright (C) 2013, NVIDIA Corporation. All rights reserved.
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#include <drm/drm_panel.h>
29
30static DEFINE_MUTEX(panel_lock);
31static LIST_HEAD(panel_list);
32
Thierry Reding83127f62016-05-06 16:01:37 +020033/**
34 * DOC: drm panel
35 *
36 * The DRM panel helpers allow drivers to register panel objects with a
37 * central registry and provide functions to retrieve those panels in display
38 * drivers.
39 */
40
41/**
42 * drm_panel_init - initialize a panel
43 * @panel: DRM panel
44 *
45 * Sets up internal fields of the panel so that it can subsequently be added
46 * to the registry.
47 */
Thierry Redingaead40e2013-08-30 13:36:43 +020048void drm_panel_init(struct drm_panel *panel)
49{
50 INIT_LIST_HEAD(&panel->list);
51}
52EXPORT_SYMBOL(drm_panel_init);
53
Thierry Reding83127f62016-05-06 16:01:37 +020054/**
55 * drm_panel_add - add a panel to the global registry
56 * @panel: panel to add
57 *
58 * Add a panel to the global registry so that it can be looked up by display
59 * drivers.
60 *
61 * Return: 0 on success or a negative error code on failure.
62 */
Thierry Redingaead40e2013-08-30 13:36:43 +020063int drm_panel_add(struct drm_panel *panel)
64{
65 mutex_lock(&panel_lock);
66 list_add_tail(&panel->list, &panel_list);
67 mutex_unlock(&panel_lock);
68
69 return 0;
70}
71EXPORT_SYMBOL(drm_panel_add);
72
Thierry Reding83127f62016-05-06 16:01:37 +020073/**
74 * drm_panel_remove - remove a panel from the global registry
75 * @panel: DRM panel
76 *
77 * Removes a panel from the global registry.
78 */
Thierry Redingaead40e2013-08-30 13:36:43 +020079void drm_panel_remove(struct drm_panel *panel)
80{
81 mutex_lock(&panel_lock);
82 list_del_init(&panel->list);
83 mutex_unlock(&panel_lock);
84}
85EXPORT_SYMBOL(drm_panel_remove);
86
Thierry Reding83127f62016-05-06 16:01:37 +020087/**
88 * drm_panel_attach - attach a panel to a connector
89 * @panel: DRM panel
90 * @connector: DRM connector
91 *
92 * After obtaining a pointer to a DRM panel a display driver calls this
93 * function to attach a panel to a connector.
94 *
95 * An error is returned if the panel is already attached to another connector.
96 *
97 * Return: 0 on success or a negative error code on failure.
98 */
Thierry Redingaead40e2013-08-30 13:36:43 +020099int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector)
100{
101 if (panel->connector)
102 return -EBUSY;
103
104 panel->connector = connector;
105 panel->drm = connector->dev;
106
107 return 0;
108}
109EXPORT_SYMBOL(drm_panel_attach);
110
Thierry Reding83127f62016-05-06 16:01:37 +0200111/**
112 * drm_panel_detach - detach a panel from a connector
113 * @panel: DRM panel
114 *
115 * Detaches a panel from the connector it is attached to. If a panel is not
116 * attached to any connector this is effectively a no-op.
117 *
118 * Return: 0 on success or a negative error code on failure.
119 */
Thierry Redingaead40e2013-08-30 13:36:43 +0200120int drm_panel_detach(struct drm_panel *panel)
121{
122 panel->connector = NULL;
123 panel->drm = NULL;
124
125 return 0;
126}
127EXPORT_SYMBOL(drm_panel_detach);
128
129#ifdef CONFIG_OF
Thierry Reding83127f62016-05-06 16:01:37 +0200130/**
131 * of_drm_find_panel - look up a panel using a device tree node
132 * @np: device tree node of the panel
133 *
134 * Searches the set of registered panels for one that matches the given device
135 * tree node. If a matching panel is found, return a pointer to it.
136 *
137 * Return: A pointer to the panel registered for the specified device tree
138 * node or NULL if no panel matching the device tree node can be found.
139 */
Thierry Redingaead40e2013-08-30 13:36:43 +0200140struct drm_panel *of_drm_find_panel(struct device_node *np)
141{
142 struct drm_panel *panel;
143
144 mutex_lock(&panel_lock);
145
146 list_for_each_entry(panel, &panel_list, list) {
147 if (panel->dev->of_node == np) {
148 mutex_unlock(&panel_lock);
149 return panel;
150 }
151 }
152
153 mutex_unlock(&panel_lock);
154 return NULL;
155}
156EXPORT_SYMBOL(of_drm_find_panel);
157#endif
158
159MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
160MODULE_DESCRIPTION("DRM panel infrastructure");
161MODULE_LICENSE("GPL and additional rights");