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aead40ea TR |
1 | /* |
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 | ||
30 | static DEFINE_MUTEX(panel_lock); | |
31 | static LIST_HEAD(panel_list); | |
32 | ||
83127f67 TR |
33 | /** |
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 | */ | |
aead40ea TR |
48 | void drm_panel_init(struct drm_panel *panel) |
49 | { | |
50 | INIT_LIST_HEAD(&panel->list); | |
51 | } | |
52 | EXPORT_SYMBOL(drm_panel_init); | |
53 | ||
83127f67 TR |
54 | /** |
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 | */ | |
aead40ea TR |
63 | int 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 | } | |
71 | EXPORT_SYMBOL(drm_panel_add); | |
72 | ||
83127f67 TR |
73 | /** |
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 | */ | |
aead40ea TR |
79 | void 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 | } | |
85 | EXPORT_SYMBOL(drm_panel_remove); | |
86 | ||
83127f67 TR |
87 | /** |
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 | * | |
38992c57 JS |
97 | * When unloading, the driver should detach from the panel by calling |
98 | * drm_panel_detach(). | |
99 | * | |
83127f67 TR |
100 | * Return: 0 on success or a negative error code on failure. |
101 | */ | |
aead40ea TR |
102 | int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector) |
103 | { | |
104 | if (panel->connector) | |
105 | return -EBUSY; | |
106 | ||
107 | panel->connector = connector; | |
108 | panel->drm = connector->dev; | |
109 | ||
110 | return 0; | |
111 | } | |
112 | EXPORT_SYMBOL(drm_panel_attach); | |
113 | ||
83127f67 TR |
114 | /** |
115 | * drm_panel_detach - detach a panel from a connector | |
116 | * @panel: DRM panel | |
117 | * | |
118 | * Detaches a panel from the connector it is attached to. If a panel is not | |
119 | * attached to any connector this is effectively a no-op. | |
120 | * | |
38992c57 JS |
121 | * This function should not be called by the panel device itself. It |
122 | * is only for the drm device that called drm_panel_attach(). | |
123 | * | |
83127f67 TR |
124 | * Return: 0 on success or a negative error code on failure. |
125 | */ | |
aead40ea TR |
126 | int drm_panel_detach(struct drm_panel *panel) |
127 | { | |
128 | panel->connector = NULL; | |
129 | panel->drm = NULL; | |
130 | ||
131 | return 0; | |
132 | } | |
133 | EXPORT_SYMBOL(drm_panel_detach); | |
134 | ||
135 | #ifdef CONFIG_OF | |
83127f67 TR |
136 | /** |
137 | * of_drm_find_panel - look up a panel using a device tree node | |
138 | * @np: device tree node of the panel | |
139 | * | |
140 | * Searches the set of registered panels for one that matches the given device | |
141 | * tree node. If a matching panel is found, return a pointer to it. | |
142 | * | |
143 | * Return: A pointer to the panel registered for the specified device tree | |
5fa8e4a2 | 144 | * node or an ERR_PTR() if no panel matching the device tree node can be found. |
3eb3cd04 | 145 | * |
c59eb3cf | 146 | * Possible error codes returned by this function: |
3eb3cd04 | 147 | * |
c59eb3cf BB |
148 | * - EPROBE_DEFER: the panel device has not been probed yet, and the caller |
149 | * should retry later | |
150 | * - ENODEV: the device is not available (status != "okay" or "ok") | |
83127f67 | 151 | */ |
327bc443 | 152 | struct drm_panel *of_drm_find_panel(const struct device_node *np) |
aead40ea TR |
153 | { |
154 | struct drm_panel *panel; | |
155 | ||
c59eb3cf BB |
156 | if (!of_device_is_available(np)) |
157 | return ERR_PTR(-ENODEV); | |
158 | ||
aead40ea TR |
159 | mutex_lock(&panel_lock); |
160 | ||
161 | list_for_each_entry(panel, &panel_list, list) { | |
162 | if (panel->dev->of_node == np) { | |
163 | mutex_unlock(&panel_lock); | |
164 | return panel; | |
165 | } | |
166 | } | |
167 | ||
168 | mutex_unlock(&panel_lock); | |
5fa8e4a2 | 169 | return ERR_PTR(-EPROBE_DEFER); |
aead40ea TR |
170 | } |
171 | EXPORT_SYMBOL(of_drm_find_panel); | |
172 | #endif | |
173 | ||
174 | MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>"); | |
175 | MODULE_DESCRIPTION("DRM panel infrastructure"); | |
176 | MODULE_LICENSE("GPL and additional rights"); |