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 #ifndef __DRM_PANEL_H__
25 #define __DRM_PANEL_H__
26
27 #include <linux/err.h>
28 #include <linux/errno.h>
29 #include <linux/list.h>
30
31 struct device_node;
32 struct drm_connector;
33 struct drm_device;
34 struct drm_panel;
35 struct display_timing;
36
37 /**
38 * struct drm_panel_funcs - perform operations on a given panel
39 *
40 * The .prepare() function is typically called before the display controller
41 * starts to transmit video data. Panel drivers can use this to turn the panel
42 * on and wait for it to become ready. If additional configuration is required
43 * (via a control bus such as I2C, SPI or DSI for example) this is a good time
44 * to do that.
45 *
46 * After the display controller has started transmitting video data, it's safe
47 * to call the .enable() function. This will typically enable the backlight to
48 * make the image on screen visible. Some panels require a certain amount of
49 * time or frames before the image is displayed. This function is responsible
50 * for taking this into account before enabling the backlight to avoid visual
51 * glitches.
52 *
53 * Before stopping video transmission from the display controller it can be
54 * necessary to turn off the panel to avoid visual glitches. This is done in
55 * the .disable() function. Analogously to .enable() this typically involves
56 * turning off the backlight and waiting for some time to make sure no image
57 * is visible on the panel. It is then safe for the display controller to
58 * cease transmission of video data.
59 *
60 * To save power when no video data is transmitted, a driver can power down
61 * the panel. This is the job of the .unprepare() function.
62 */
63 struct drm_panel_funcs {
64 /**
65 * @prepare:
66 *
67 * Turn on panel and perform set up.
68 */
69 int (*prepare)(struct drm_panel *panel);
70
71 /**
72 * @enable:
73 *
74 * Enable panel (turn on back light, etc.).
75 */
76 int (*enable)(struct drm_panel *panel);
77
78 /**
79 * @disable:
80 *
81 * Disable panel (turn off back light, etc.).
82 */
83 int (*disable)(struct drm_panel *panel);
84
85 /**
86 * @unprepare:
87 *
88 * Turn off panel.
89 */
90 int (*unprepare)(struct drm_panel *panel);
91
92 /**
93 * @get_modes:
94 *
95 * Add modes to the connector that the panel is attached to and
96 * return the number of modes added.
97 */
98 int (*get_modes)(struct drm_panel *panel);
99
100 /**
101 * @get_timings:
102 *
103 * Copy display timings into the provided array and return
104 * the number of display timings available.
105 */
106 int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
107 struct display_timing *timings);
108 };
109
110 /**
111 * struct drm_panel - DRM panel object
112 */
113 struct drm_panel {
114 /**
115 * @drm:
116 *
117 * DRM device owning the panel.
118 */
119 struct drm_device *drm;
120
121 /**
122 * @connector:
123 *
124 * DRM connector that the panel is attached to.
125 */
126 struct drm_connector *connector;
127
128 /**
129 * @dev:
130 *
131 * Parent device of the panel.
132 */
133 struct device *dev;
134
135 /**
136 * @funcs:
137 *
138 * Operations that can be performed on the panel.
139 */
140 const struct drm_panel_funcs *funcs;
141
142 /**
143 * @list:
144 *
145 * Panel entry in registry.
146 */
147 struct list_head list;
148 };
149
150 void drm_panel_init(struct drm_panel *panel);
151
152 int drm_panel_add(struct drm_panel *panel);
153 void drm_panel_remove(struct drm_panel *panel);
154
155 int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector);
156 void drm_panel_detach(struct drm_panel *panel);
157
158 int drm_panel_prepare(struct drm_panel *panel);
159 int drm_panel_unprepare(struct drm_panel *panel);
160
161 int drm_panel_enable(struct drm_panel *panel);
162 int drm_panel_disable(struct drm_panel *panel);
163
164 int drm_panel_get_modes(struct drm_panel *panel);
165
166 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
167 struct drm_panel *of_drm_find_panel(const struct device_node *np);
168 #else
169 static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
170 {
171 return ERR_PTR(-ENODEV);
172 }
173 #endif
174
175 #endif