summaryrefslogtreecommitdiff
path: root/include/drm/drm_panel.h
blob: d6c73f79c131e3c89251d5c2ea58d5ea7f9fa6f6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
/*
 * Copyright (C) 2013, NVIDIA Corporation.  All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sub license,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#ifndef __DRM_PANEL_H__
#define __DRM_PANEL_H__

#include <linux/err.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/mutex.h>

struct backlight_device;
struct dentry;
struct device_node;
struct drm_connector;
struct drm_device;
struct drm_panel_follower;
struct drm_panel;
struct display_timing;

enum drm_panel_orientation;

/**
 * struct drm_panel_funcs - perform operations on a given panel
 *
 * The .prepare() function is typically called before the display controller
 * starts to transmit video data. Panel drivers can use this to turn the panel
 * on and wait for it to become ready. If additional configuration is required
 * (via a control bus such as I2C, SPI or DSI for example) this is a good time
 * to do that.
 *
 * After the display controller has started transmitting video data, it's safe
 * to call the .enable() function. This will typically enable the backlight to
 * make the image on screen visible. Some panels require a certain amount of
 * time or frames before the image is displayed. This function is responsible
 * for taking this into account before enabling the backlight to avoid visual
 * glitches.
 *
 * Before stopping video transmission from the display controller it can be
 * necessary to turn off the panel to avoid visual glitches. This is done in
 * the .disable() function. Analogously to .enable() this typically involves
 * turning off the backlight and waiting for some time to make sure no image
 * is visible on the panel. It is then safe for the display controller to
 * cease transmission of video data.
 *
 * To save power when no video data is transmitted, a driver can power down
 * the panel. This is the job of the .unprepare() function.
 *
 * Backlight can be handled automatically if configured using
 * drm_panel_of_backlight() or drm_panel_dp_aux_backlight(). Then the driver
 * does not need to implement the functionality to enable/disable backlight.
 */
struct drm_panel_funcs {
	/**
	 * @prepare:
	 *
	 * Turn on panel and perform set up.
	 *
	 * This function is optional.
	 */
	int (*prepare)(struct drm_panel *panel);

	/**
	 * @enable:
	 *
	 * Enable panel (turn on back light, etc.).
	 *
	 * This function is optional.
	 */
	int (*enable)(struct drm_panel *panel);

	/**
	 * @disable:
	 *
	 * Disable panel (turn off back light, etc.).
	 *
	 * This function is optional.
	 */
	int (*disable)(struct drm_panel *panel);

	/**
	 * @unprepare:
	 *
	 * Turn off panel.
	 *
	 * This function is optional.
	 */
	int (*unprepare)(struct drm_panel *panel);

	/**
	 * @get_modes:
	 *
	 * Add modes to the connector that the panel is attached to
	 * and returns the number of modes added.
	 *
	 * This function is mandatory.
	 */
	int (*get_modes)(struct drm_panel *panel,
			 struct drm_connector *connector);

	/**
	 * @get_orientation:
	 *
	 * Return the panel orientation set by device tree or EDID.
	 *
	 * This function is optional.
	 */
	enum drm_panel_orientation (*get_orientation)(struct drm_panel *panel);

	/**
	 * @get_timings:
	 *
	 * Copy display timings into the provided array and return
	 * the number of display timings available.
	 *
	 * This function is optional.
	 */
	int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
			   struct display_timing *timings);

	/**
	 * @debugfs_init:
	 *
	 * Allows panels to create panels-specific debugfs files.
	 */
	void (*debugfs_init)(struct drm_panel *panel, struct dentry *root);
};

struct drm_panel_follower_funcs {
	/**
	 * @panel_prepared:
	 *
	 * Called after the panel has been powered on.
	 */
	int (*panel_prepared)(struct drm_panel_follower *follower);

	/**
	 * @panel_unpreparing:
	 *
	 * Called before the panel is powered off.
	 */
	int (*panel_unpreparing)(struct drm_panel_follower *follower);
};

struct drm_panel_follower {
	/**
	 * @funcs:
	 *
	 * Dependent device callbacks; should be initted by the caller.
	 */
	const struct drm_panel_follower_funcs *funcs;

	/**
	 * @list
	 *
	 * Used for linking into panel's list; set by drm_panel_add_follower().
	 */
	struct list_head list;

	/**
	 * @panel
	 *
	 * The panel we're dependent on; set by drm_panel_add_follower().
	 */
	struct drm_panel *panel;
};

/**
 * struct drm_panel - DRM panel object
 */
struct drm_panel {
	/**
	 * @dev:
	 *
	 * Parent device of the panel.
	 */
	struct device *dev;

	/**
	 * @backlight:
	 *
	 * Backlight device, used to turn on backlight after the call
	 * to enable(), and to turn off backlight before the call to
	 * disable().
	 * backlight is set by drm_panel_of_backlight() or
	 * drm_panel_dp_aux_backlight() and drivers shall not assign it.
	 */
	struct backlight_device *backlight;

	/**
	 * @funcs:
	 *
	 * Operations that can be performed on the panel.
	 */
	const struct drm_panel_funcs *funcs;

	/**
	 * @connector_type:
	 *
	 * Type of the panel as a DRM_MODE_CONNECTOR_* value. This is used to
	 * initialise the drm_connector corresponding to the panel with the
	 * correct connector type.
	 */
	int connector_type;

	/**
	 * @list:
	 *
	 * Panel entry in registry.
	 */
	struct list_head list;

	/**
	 * @followers:
	 *
	 * A list of struct drm_panel_follower dependent on this panel.
	 */
	struct list_head followers;

	/**
	 * @followers_lock:
	 *
	 * Lock for followers list.
	 */
	struct mutex follower_lock;

	/**
	 * @prepare_prev_first:
	 *
	 * The previous controller should be prepared first, before the prepare
	 * for the panel is called. This is largely required for DSI panels
	 * where the DSI host controller should be initialised to LP-11 before
	 * the panel is powered up.
	 */
	bool prepare_prev_first;

	/**
	 * @prepared:
	 *
	 * If true then the panel has been prepared.
	 */
	bool prepared;

	/**
	 * @enabled:
	 *
	 * If true then the panel has been enabled.
	 */
	bool enabled;
};

void drm_panel_init(struct drm_panel *panel, struct device *dev,
		    const struct drm_panel_funcs *funcs,
		    int connector_type);

void drm_panel_add(struct drm_panel *panel);
void drm_panel_remove(struct drm_panel *panel);

int drm_panel_prepare(struct drm_panel *panel);
int drm_panel_unprepare(struct drm_panel *panel);

int drm_panel_enable(struct drm_panel *panel);
int drm_panel_disable(struct drm_panel *panel);

int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector);

#if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
struct drm_panel *of_drm_find_panel(const struct device_node *np);
int of_drm_get_panel_orientation(const struct device_node *np,
				 enum drm_panel_orientation *orientation);
#else
static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
{
	return ERR_PTR(-ENODEV);
}

static inline int of_drm_get_panel_orientation(const struct device_node *np,
					       enum drm_panel_orientation *orientation)
{
	return -ENODEV;
}
#endif

#if defined(CONFIG_DRM_PANEL)
bool drm_is_panel_follower(struct device *dev);
int drm_panel_add_follower(struct device *follower_dev,
			   struct drm_panel_follower *follower);
void drm_panel_remove_follower(struct drm_panel_follower *follower);
int devm_drm_panel_add_follower(struct device *follower_dev,
				struct drm_panel_follower *follower);
#else
static inline bool drm_is_panel_follower(struct device *dev)
{
	return false;
}

static inline int drm_panel_add_follower(struct device *follower_dev,
					 struct drm_panel_follower *follower)
{
	return -ENODEV;
}

static inline void drm_panel_remove_follower(struct drm_panel_follower *follower) { }
static inline int devm_drm_panel_add_follower(struct device *follower_dev,
					      struct drm_panel_follower *follower)
{
	return -ENODEV;
}
#endif

#if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
	(IS_MODULE(CONFIG_DRM) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
int drm_panel_of_backlight(struct drm_panel *panel);
#else
static inline int drm_panel_of_backlight(struct drm_panel *panel)
{
	return 0;
}
#endif

#endif