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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#include <linux/mutex.h>
31
32struct backlight_device;
33struct dentry;
34struct device_node;
35struct drm_connector;
36struct drm_device;
37struct drm_panel_follower;
38struct drm_panel;
39struct display_timing;
40
41enum drm_panel_orientation;
42
43/**
44 * struct drm_panel_funcs - perform operations on a given panel
45 *
46 * The .prepare() function is typically called before the display controller
47 * starts to transmit video data. Panel drivers can use this to turn the panel
48 * on and wait for it to become ready. If additional configuration is required
49 * (via a control bus such as I2C, SPI or DSI for example) this is a good time
50 * to do that.
51 *
52 * After the display controller has started transmitting video data, it's safe
53 * to call the .enable() function. This will typically enable the backlight to
54 * make the image on screen visible. Some panels require a certain amount of
55 * time or frames before the image is displayed. This function is responsible
56 * for taking this into account before enabling the backlight to avoid visual
57 * glitches.
58 *
59 * Before stopping video transmission from the display controller it can be
60 * necessary to turn off the panel to avoid visual glitches. This is done in
61 * the .disable() function. Analogously to .enable() this typically involves
62 * turning off the backlight and waiting for some time to make sure no image
63 * is visible on the panel. It is then safe for the display controller to
64 * cease transmission of video data.
65 *
66 * To save power when no video data is transmitted, a driver can power down
67 * the panel. This is the job of the .unprepare() function.
68 *
69 * Backlight can be handled automatically if configured using
70 * drm_panel_of_backlight() or drm_panel_dp_aux_backlight(). Then the driver
71 * does not need to implement the functionality to enable/disable backlight.
72 */
73struct drm_panel_funcs {
74 /**
75 * @prepare:
76 *
77 * Turn on panel and perform set up.
78 *
79 * This function is optional.
80 */
81 int (*prepare)(struct drm_panel *panel);
82
83 /**
84 * @enable:
85 *
86 * Enable panel (turn on back light, etc.).
87 *
88 * This function is optional.
89 */
90 int (*enable)(struct drm_panel *panel);
91
92 /**
93 * @disable:
94 *
95 * Disable panel (turn off back light, etc.).
96 *
97 * This function is optional.
98 */
99 int (*disable)(struct drm_panel *panel);
100
101 /**
102 * @unprepare:
103 *
104 * Turn off panel.
105 *
106 * This function is optional.
107 */
108 int (*unprepare)(struct drm_panel *panel);
109
110 /**
111 * @get_modes:
112 *
113 * Add modes to the connector that the panel is attached to
114 * and returns the number of modes added.
115 *
116 * This function is mandatory.
117 */
118 int (*get_modes)(struct drm_panel *panel,
119 struct drm_connector *connector);
120
121 /**
122 * @get_orientation:
123 *
124 * Return the panel orientation set by device tree or EDID.
125 *
126 * This function is optional.
127 */
128 enum drm_panel_orientation (*get_orientation)(struct drm_panel *panel);
129
130 /**
131 * @get_timings:
132 *
133 * Copy display timings into the provided array and return
134 * the number of display timings available.
135 *
136 * This function is optional.
137 */
138 int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
139 struct display_timing *timings);
140
141 /**
142 * @debugfs_init:
143 *
144 * Allows panels to create panels-specific debugfs files.
145 */
146 void (*debugfs_init)(struct drm_panel *panel, struct dentry *root);
147};
148
149struct drm_panel_follower_funcs {
150 /**
151 * @panel_prepared:
152 *
153 * Called after the panel has been powered on.
154 */
155 int (*panel_prepared)(struct drm_panel_follower *follower);
156
157 /**
158 * @panel_unpreparing:
159 *
160 * Called before the panel is powered off.
161 */
162 int (*panel_unpreparing)(struct drm_panel_follower *follower);
163};
164
165struct drm_panel_follower {
166 /**
167 * @funcs:
168 *
169 * Dependent device callbacks; should be initted by the caller.
170 */
171 const struct drm_panel_follower_funcs *funcs;
172
173 /**
174 * @list
175 *
176 * Used for linking into panel's list; set by drm_panel_add_follower().
177 */
178 struct list_head list;
179
180 /**
181 * @panel
182 *
183 * The panel we're dependent on; set by drm_panel_add_follower().
184 */
185 struct drm_panel *panel;
186};
187
188/**
189 * struct drm_panel - DRM panel object
190 */
191struct drm_panel {
192 /**
193 * @dev:
194 *
195 * Parent device of the panel.
196 */
197 struct device *dev;
198
199 /**
200 * @backlight:
201 *
202 * Backlight device, used to turn on backlight after the call
203 * to enable(), and to turn off backlight before the call to
204 * disable().
205 * backlight is set by drm_panel_of_backlight() or
206 * drm_panel_dp_aux_backlight() and drivers shall not assign it.
207 */
208 struct backlight_device *backlight;
209
210 /**
211 * @funcs:
212 *
213 * Operations that can be performed on the panel.
214 */
215 const struct drm_panel_funcs *funcs;
216
217 /**
218 * @connector_type:
219 *
220 * Type of the panel as a DRM_MODE_CONNECTOR_* value. This is used to
221 * initialise the drm_connector corresponding to the panel with the
222 * correct connector type.
223 */
224 int connector_type;
225
226 /**
227 * @list:
228 *
229 * Panel entry in registry.
230 */
231 struct list_head list;
232
233 /**
234 * @followers:
235 *
236 * A list of struct drm_panel_follower dependent on this panel.
237 */
238 struct list_head followers;
239
240 /**
241 * @follower_lock:
242 *
243 * Lock for followers list.
244 */
245 struct mutex follower_lock;
246
247 /**
248 * @prepare_prev_first:
249 *
250 * The previous controller should be prepared first, before the prepare
251 * for the panel is called. This is largely required for DSI panels
252 * where the DSI host controller should be initialised to LP-11 before
253 * the panel is powered up.
254 */
255 bool prepare_prev_first;
256
257 /**
258 * @prepared:
259 *
260 * If true then the panel has been prepared.
261 */
262 bool prepared;
263
264 /**
265 * @enabled:
266 *
267 * If true then the panel has been enabled.
268 */
269 bool enabled;
270};
271
272void drm_panel_init(struct drm_panel *panel, struct device *dev,
273 const struct drm_panel_funcs *funcs,
274 int connector_type);
275
276void drm_panel_add(struct drm_panel *panel);
277void drm_panel_remove(struct drm_panel *panel);
278
279int drm_panel_prepare(struct drm_panel *panel);
280int drm_panel_unprepare(struct drm_panel *panel);
281
282int drm_panel_enable(struct drm_panel *panel);
283int drm_panel_disable(struct drm_panel *panel);
284
285int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector);
286
287#if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
288struct drm_panel *of_drm_find_panel(const struct device_node *np);
289int of_drm_get_panel_orientation(const struct device_node *np,
290 enum drm_panel_orientation *orientation);
291#else
292static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
293{
294 return ERR_PTR(-ENODEV);
295}
296
297static inline int of_drm_get_panel_orientation(const struct device_node *np,
298 enum drm_panel_orientation *orientation)
299{
300 return -ENODEV;
301}
302#endif
303
304#if defined(CONFIG_DRM_PANEL)
305bool drm_is_panel_follower(struct device *dev);
306int drm_panel_add_follower(struct device *follower_dev,
307 struct drm_panel_follower *follower);
308void drm_panel_remove_follower(struct drm_panel_follower *follower);
309int devm_drm_panel_add_follower(struct device *follower_dev,
310 struct drm_panel_follower *follower);
311#else
312static inline bool drm_is_panel_follower(struct device *dev)
313{
314 return false;
315}
316
317static inline int drm_panel_add_follower(struct device *follower_dev,
318 struct drm_panel_follower *follower)
319{
320 return -ENODEV;
321}
322
323static inline void drm_panel_remove_follower(struct drm_panel_follower *follower) { }
324static inline int devm_drm_panel_add_follower(struct device *follower_dev,
325 struct drm_panel_follower *follower)
326{
327 return -ENODEV;
328}
329#endif
330
331#if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
332 (IS_MODULE(CONFIG_DRM) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
333int drm_panel_of_backlight(struct drm_panel *panel);
334#else
335static inline int drm_panel_of_backlight(struct drm_panel *panel)
336{
337 return 0;
338}
339#endif
340
341#endif
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/list.h>
28
29struct drm_connector;
30struct drm_device;
31struct drm_panel;
32struct display_timing;
33
34/**
35 * struct drm_panel_funcs - perform operations on a given panel
36 * @disable: disable panel (turn off back light, etc.)
37 * @unprepare: turn off panel
38 * @prepare: turn on panel and perform set up
39 * @enable: enable panel (turn on back light, etc.)
40 * @get_modes: add modes to the connector that the panel is attached to and
41 * return the number of modes added
42 * @get_timings: copy display timings into the provided array and return
43 * the number of display timings available
44 *
45 * The .prepare() function is typically called before the display controller
46 * starts to transmit video data. Panel drivers can use this to turn the panel
47 * on and wait for it to become ready. If additional configuration is required
48 * (via a control bus such as I2C, SPI or DSI for example) this is a good time
49 * to do that.
50 *
51 * After the display controller has started transmitting video data, it's safe
52 * to call the .enable() function. This will typically enable the backlight to
53 * make the image on screen visible. Some panels require a certain amount of
54 * time or frames before the image is displayed. This function is responsible
55 * for taking this into account before enabling the backlight to avoid visual
56 * glitches.
57 *
58 * Before stopping video transmission from the display controller it can be
59 * necessary to turn off the panel to avoid visual glitches. This is done in
60 * the .disable() function. Analogously to .enable() this typically involves
61 * turning off the backlight and waiting for some time to make sure no image
62 * is visible on the panel. It is then safe for the display controller to
63 * cease transmission of video data.
64 *
65 * To save power when no video data is transmitted, a driver can power down
66 * the panel. This is the job of the .unprepare() function.
67 */
68struct drm_panel_funcs {
69 int (*disable)(struct drm_panel *panel);
70 int (*unprepare)(struct drm_panel *panel);
71 int (*prepare)(struct drm_panel *panel);
72 int (*enable)(struct drm_panel *panel);
73 int (*get_modes)(struct drm_panel *panel);
74 int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
75 struct display_timing *timings);
76};
77
78/**
79 * struct drm_panel - DRM panel object
80 * @drm: DRM device owning the panel
81 * @connector: DRM connector that the panel is attached to
82 * @dev: parent device of the panel
83 * @funcs: operations that can be performed on the panel
84 * @list: panel entry in registry
85 */
86struct drm_panel {
87 struct drm_device *drm;
88 struct drm_connector *connector;
89 struct device *dev;
90
91 const struct drm_panel_funcs *funcs;
92
93 struct list_head list;
94};
95
96/**
97 * drm_disable_unprepare - power off a panel
98 * @panel: DRM panel
99 *
100 * Calling this function will completely power off a panel (assert the panel's
101 * reset, turn off power supplies, ...). After this function has completed, it
102 * is usually no longer possible to communicate with the panel until another
103 * call to drm_panel_prepare().
104 *
105 * Return: 0 on success or a negative error code on failure.
106 */
107static inline int drm_panel_unprepare(struct drm_panel *panel)
108{
109 if (panel && panel->funcs && panel->funcs->unprepare)
110 return panel->funcs->unprepare(panel);
111
112 return panel ? -ENOSYS : -EINVAL;
113}
114
115/**
116 * drm_panel_disable - disable a panel
117 * @panel: DRM panel
118 *
119 * This will typically turn off the panel's backlight or disable the display
120 * drivers. For smart panels it should still be possible to communicate with
121 * the integrated circuitry via any command bus after this call.
122 *
123 * Return: 0 on success or a negative error code on failure.
124 */
125static inline int drm_panel_disable(struct drm_panel *panel)
126{
127 if (panel && panel->funcs && panel->funcs->disable)
128 return panel->funcs->disable(panel);
129
130 return panel ? -ENOSYS : -EINVAL;
131}
132
133/**
134 * drm_panel_prepare - power on a panel
135 * @panel: DRM panel
136 *
137 * Calling this function will enable power and deassert any reset signals to
138 * the panel. After this has completed it is possible to communicate with any
139 * integrated circuitry via a command bus.
140 *
141 * Return: 0 on success or a negative error code on failure.
142 */
143static inline int drm_panel_prepare(struct drm_panel *panel)
144{
145 if (panel && panel->funcs && panel->funcs->prepare)
146 return panel->funcs->prepare(panel);
147
148 return panel ? -ENOSYS : -EINVAL;
149}
150
151/**
152 * drm_panel_enable - enable a panel
153 * @panel: DRM panel
154 *
155 * Calling this function will cause the panel display drivers to be turned on
156 * and the backlight to be enabled. Content will be visible on screen after
157 * this call completes.
158 *
159 * Return: 0 on success or a negative error code on failure.
160 */
161static inline int drm_panel_enable(struct drm_panel *panel)
162{
163 if (panel && panel->funcs && panel->funcs->enable)
164 return panel->funcs->enable(panel);
165
166 return panel ? -ENOSYS : -EINVAL;
167}
168
169/**
170 * drm_panel_get_modes - probe the available display modes of a panel
171 * @panel: DRM panel
172 *
173 * The modes probed from the panel are automatically added to the connector
174 * that the panel is attached to.
175 *
176 * Return: The number of modes available from the panel on success or a
177 * negative error code on failure.
178 */
179static inline int drm_panel_get_modes(struct drm_panel *panel)
180{
181 if (panel && panel->funcs && panel->funcs->get_modes)
182 return panel->funcs->get_modes(panel);
183
184 return panel ? -ENOSYS : -EINVAL;
185}
186
187void drm_panel_init(struct drm_panel *panel);
188
189int drm_panel_add(struct drm_panel *panel);
190void drm_panel_remove(struct drm_panel *panel);
191
192int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector);
193int drm_panel_detach(struct drm_panel *panel);
194
195#ifdef CONFIG_OF
196struct drm_panel *of_drm_find_panel(struct device_node *np);
197#else
198static inline struct drm_panel *of_drm_find_panel(struct device_node *np)
199{
200 return NULL;
201}
202#endif
203
204#endif