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 backlight_device;
32 struct device_node;
33 struct drm_connector;
34 struct drm_device;
35 struct drm_panel;
36 struct display_timing;
37
38 enum drm_panel_orientation;
39
40 /**
41 * struct drm_panel_funcs - perform operations on a given panel
42 *
43 * The .prepare() function is typically called before the display controller
44 * starts to transmit video data. Panel drivers can use this to turn the panel
45 * on and wait for it to become ready. If additional configuration is required
46 * (via a control bus such as I2C, SPI or DSI for example) this is a good time
47 * to do that.
48 *
49 * After the display controller has started transmitting video data, it's safe
50 * to call the .enable() function. This will typically enable the backlight to
51 * make the image on screen visible. Some panels require a certain amount of
52 * time or frames before the image is displayed. This function is responsible
53 * for taking this into account before enabling the backlight to avoid visual
54 * glitches.
55 *
56 * Before stopping video transmission from the display controller it can be
57 * necessary to turn off the panel to avoid visual glitches. This is done in
58 * the .disable() function. Analogously to .enable() this typically involves
59 * turning off the backlight and waiting for some time to make sure no image
60 * is visible on the panel. It is then safe for the display controller to
61 * cease transmission of video data.
62 *
63 * To save power when no video data is transmitted, a driver can power down
64 * the panel. This is the job of the .unprepare() function.
65 *
66 * Backlight can be handled automatically if configured using
67 * drm_panel_of_backlight() or drm_panel_dp_aux_backlight(). Then the driver
68 * does not need to implement the functionality to enable/disable backlight.
69 */
70 struct drm_panel_funcs {
71 /**
72 * @prepare:
73 *
74 * Turn on panel and perform set up.
75 *
76 * This function is optional.
77 */
78 int (*prepare)(struct drm_panel *panel);
79
80 /**
81 * @enable:
82 *
83 * Enable panel (turn on back light, etc.).
84 *
85 * This function is optional.
86 */
87 int (*enable)(struct drm_panel *panel);
88
89 /**
90 * @disable:
91 *
92 * Disable panel (turn off back light, etc.).
93 *
94 * This function is optional.
95 */
96 int (*disable)(struct drm_panel *panel);
97
98 /**
99 * @unprepare:
100 *
101 * Turn off panel.
102 *
103 * This function is optional.
104 */
105 int (*unprepare)(struct drm_panel *panel);
106
107 /**
108 * @get_modes:
109 *
110 * Add modes to the connector that the panel is attached to
111 * and returns the number of modes added.
112 *
113 * This function is mandatory.
114 */
115 int (*get_modes)(struct drm_panel *panel,
116 struct drm_connector *connector);
117
118 /**
119 * @get_timings:
120 *
121 * Copy display timings into the provided array and return
122 * the number of display timings available.
123 *
124 * This function is optional.
125 */
126 int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
127 struct display_timing *timings);
128 };
129
130 /**
131 * struct drm_panel - DRM panel object
132 */
133 struct drm_panel {
134 /**
135 * @dev:
136 *
137 * Parent device of the panel.
138 */
139 struct device *dev;
140
141 /**
142 * @backlight:
143 *
144 * Backlight device, used to turn on backlight after the call
145 * to enable(), and to turn off backlight before the call to
146 * disable().
147 * backlight is set by drm_panel_of_backlight() or
148 * drm_panel_dp_aux_backlight() and drivers shall not assign it.
149 */
150 struct backlight_device *backlight;
151
152 /**
153 * @funcs:
154 *
155 * Operations that can be performed on the panel.
156 */
157 const struct drm_panel_funcs *funcs;
158
159 /**
160 * @connector_type:
161 *
162 * Type of the panel as a DRM_MODE_CONNECTOR_* value. This is used to
163 * initialise the drm_connector corresponding to the panel with the
164 * correct connector type.
165 */
166 int connector_type;
167
168 /**
169 * @list:
170 *
171 * Panel entry in registry.
172 */
173 struct list_head list;
174 };
175
176 void drm_panel_init(struct drm_panel *panel, struct device *dev,
177 const struct drm_panel_funcs *funcs,
178 int connector_type);
179
180 void drm_panel_add(struct drm_panel *panel);
181 void drm_panel_remove(struct drm_panel *panel);
182
183 int drm_panel_prepare(struct drm_panel *panel);
184 int drm_panel_unprepare(struct drm_panel *panel);
185
186 int drm_panel_enable(struct drm_panel *panel);
187 int drm_panel_disable(struct drm_panel *panel);
188
189 int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector);
190
191 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
192 struct drm_panel *of_drm_find_panel(const struct device_node *np);
193 int of_drm_get_panel_orientation(const struct device_node *np,
194 enum drm_panel_orientation *orientation);
195 #else
of_drm_find_panel(const struct device_node * np)196 static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
197 {
198 return ERR_PTR(-ENODEV);
199 }
200
of_drm_get_panel_orientation(const struct device_node * np,enum drm_panel_orientation * orientation)201 static inline int of_drm_get_panel_orientation(const struct device_node *np,
202 enum drm_panel_orientation *orientation)
203 {
204 return -ENODEV;
205 }
206 #endif
207
208 #if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
209 (IS_MODULE(CONFIG_DRM) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
210 int drm_panel_of_backlight(struct drm_panel *panel);
211 #else
drm_panel_of_backlight(struct drm_panel * panel)212 static inline int drm_panel_of_backlight(struct drm_panel *panel)
213 {
214 return 0;
215 }
216 #endif
217
218 #endif
219