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 dentry;
33 struct device_node;
34 struct drm_connector;
35 struct drm_device;
36 struct drm_panel;
37 struct display_timing;
38
39 enum drm_panel_orientation;
40
41 /**
42 * struct drm_panel_funcs - perform operations on a given panel
43 *
44 * The .prepare() function is typically called before the display controller
45 * starts to transmit video data. Panel drivers can use this to turn the panel
46 * on and wait for it to become ready. If additional configuration is required
47 * (via a control bus such as I2C, SPI or DSI for example) this is a good time
48 * to do that.
49 *
50 * After the display controller has started transmitting video data, it's safe
51 * to call the .enable() function. This will typically enable the backlight to
52 * make the image on screen visible. Some panels require a certain amount of
53 * time or frames before the image is displayed. This function is responsible
54 * for taking this into account before enabling the backlight to avoid visual
55 * glitches.
56 *
57 * Before stopping video transmission from the display controller it can be
58 * necessary to turn off the panel to avoid visual glitches. This is done in
59 * the .disable() function. Analogously to .enable() this typically involves
60 * turning off the backlight and waiting for some time to make sure no image
61 * is visible on the panel. It is then safe for the display controller to
62 * cease transmission of video data.
63 *
64 * To save power when no video data is transmitted, a driver can power down
65 * the panel. This is the job of the .unprepare() function.
66 *
67 * Backlight can be handled automatically if configured using
68 * drm_panel_of_backlight() or drm_panel_dp_aux_backlight(). Then the driver
69 * does not need to implement the functionality to enable/disable backlight.
70 */
71 struct drm_panel_funcs {
72 /**
73 * @prepare:
74 *
75 * Turn on panel and perform set up.
76 *
77 * This function is optional.
78 */
79 int (*prepare)(struct drm_panel *panel);
80
81 /**
82 * @enable:
83 *
84 * Enable panel (turn on back light, etc.).
85 *
86 * This function is optional.
87 */
88 int (*enable)(struct drm_panel *panel);
89
90 /**
91 * @disable:
92 *
93 * Disable panel (turn off back light, etc.).
94 *
95 * This function is optional.
96 */
97 int (*disable)(struct drm_panel *panel);
98
99 /**
100 * @unprepare:
101 *
102 * Turn off panel.
103 *
104 * This function is optional.
105 */
106 int (*unprepare)(struct drm_panel *panel);
107
108 /**
109 * @get_modes:
110 *
111 * Add modes to the connector that the panel is attached to
112 * and returns the number of modes added.
113 *
114 * This function is mandatory.
115 */
116 int (*get_modes)(struct drm_panel *panel,
117 struct drm_connector *connector);
118
119 /**
120 * @get_orientation:
121 *
122 * Return the panel orientation set by device tree or EDID.
123 *
124 * This function is optional.
125 */
126 enum drm_panel_orientation (*get_orientation)(struct drm_panel *panel);
127
128 /**
129 * @get_timings:
130 *
131 * Copy display timings into the provided array and return
132 * the number of display timings available.
133 *
134 * This function is optional.
135 */
136 int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
137 struct display_timing *timings);
138
139 /**
140 * @debugfs_init:
141 *
142 * Allows panels to create panels-specific debugfs files.
143 */
144 void (*debugfs_init)(struct drm_panel *panel, struct dentry *root);
145 };
146
147 /**
148 * struct drm_panel - DRM panel object
149 */
150 struct drm_panel {
151 /**
152 * @dev:
153 *
154 * Parent device of the panel.
155 */
156 struct device *dev;
157
158 /**
159 * @backlight:
160 *
161 * Backlight device, used to turn on backlight after the call
162 * to enable(), and to turn off backlight before the call to
163 * disable().
164 * backlight is set by drm_panel_of_backlight() or
165 * drm_panel_dp_aux_backlight() and drivers shall not assign it.
166 */
167 struct backlight_device *backlight;
168
169 /**
170 * @funcs:
171 *
172 * Operations that can be performed on the panel.
173 */
174 const struct drm_panel_funcs *funcs;
175
176 /**
177 * @connector_type:
178 *
179 * Type of the panel as a DRM_MODE_CONNECTOR_* value. This is used to
180 * initialise the drm_connector corresponding to the panel with the
181 * correct connector type.
182 */
183 int connector_type;
184
185 /**
186 * @list:
187 *
188 * Panel entry in registry.
189 */
190 struct list_head list;
191 };
192
193 void drm_panel_init(struct drm_panel *panel, struct device *dev,
194 const struct drm_panel_funcs *funcs,
195 int connector_type);
196
197 void drm_panel_add(struct drm_panel *panel);
198 void drm_panel_remove(struct drm_panel *panel);
199
200 int drm_panel_prepare(struct drm_panel *panel);
201 int drm_panel_unprepare(struct drm_panel *panel);
202
203 int drm_panel_enable(struct drm_panel *panel);
204 int drm_panel_disable(struct drm_panel *panel);
205
206 int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector);
207
208 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
209 struct drm_panel *of_drm_find_panel(const struct device_node *np);
210 int of_drm_get_panel_orientation(const struct device_node *np,
211 enum drm_panel_orientation *orientation);
212 #else
of_drm_find_panel(const struct device_node * np)213 static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
214 {
215 return ERR_PTR(-ENODEV);
216 }
217
of_drm_get_panel_orientation(const struct device_node * np,enum drm_panel_orientation * orientation)218 static inline int of_drm_get_panel_orientation(const struct device_node *np,
219 enum drm_panel_orientation *orientation)
220 {
221 return -ENODEV;
222 }
223 #endif
224
225 #if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
226 (IS_MODULE(CONFIG_DRM) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
227 int drm_panel_of_backlight(struct drm_panel *panel);
228 #else
drm_panel_of_backlight(struct drm_panel * panel)229 static inline int drm_panel_of_backlight(struct drm_panel *panel)
230 {
231 return 0;
232 }
233 #endif
234
235 #endif
236
