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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#include <linux/kref.h>
32
33struct backlight_device;
34struct dentry;
35struct device_node;
36struct drm_connector;
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 /**
165 * @panel_enabled:
166 *
167 * Called after the panel and the backlight have been enabled.
168 */
169 int (*panel_enabled)(struct drm_panel_follower *follower);
170
171 /**
172 * @panel_disabling:
173 *
174 * Called before the panel and the backlight are disabled.
175 */
176 int (*panel_disabling)(struct drm_panel_follower *follower);
177};
178
179struct drm_panel_follower {
180 /**
181 * @funcs:
182 *
183 * Dependent device callbacks; should be initted by the caller.
184 */
185 const struct drm_panel_follower_funcs *funcs;
186
187 /**
188 * @list
189 *
190 * Used for linking into panel's list; set by drm_panel_add_follower().
191 */
192 struct list_head list;
193
194 /**
195 * @panel
196 *
197 * The panel we're dependent on; set by drm_panel_add_follower().
198 */
199 struct drm_panel *panel;
200};
201
202/**
203 * struct drm_panel - DRM panel object
204 */
205struct drm_panel {
206 /**
207 * @dev:
208 *
209 * Parent device of the panel.
210 */
211 struct device *dev;
212
213 /**
214 * @backlight:
215 *
216 * Backlight device, used to turn on backlight after the call
217 * to enable(), and to turn off backlight before the call to
218 * disable().
219 * backlight is set by drm_panel_of_backlight() or
220 * drm_panel_dp_aux_backlight() and drivers shall not assign it.
221 */
222 struct backlight_device *backlight;
223
224 /**
225 * @funcs:
226 *
227 * Operations that can be performed on the panel.
228 */
229 const struct drm_panel_funcs *funcs;
230
231 /**
232 * @connector_type:
233 *
234 * Type of the panel as a DRM_MODE_CONNECTOR_* value. This is used to
235 * initialise the drm_connector corresponding to the panel with the
236 * correct connector type.
237 */
238 int connector_type;
239
240 /**
241 * @list:
242 *
243 * Panel entry in registry.
244 */
245 struct list_head list;
246
247 /**
248 * @followers:
249 *
250 * A list of struct drm_panel_follower dependent on this panel.
251 */
252 struct list_head followers;
253
254 /**
255 * @follower_lock:
256 *
257 * Lock for followers list.
258 */
259 struct mutex follower_lock;
260
261 /**
262 * @prepare_prev_first:
263 *
264 * The previous controller should be prepared first, before the prepare
265 * for the panel is called. This is largely required for DSI panels
266 * where the DSI host controller should be initialised to LP-11 before
267 * the panel is powered up.
268 */
269 bool prepare_prev_first;
270
271 /**
272 * @prepared:
273 *
274 * If true then the panel has been prepared.
275 */
276 bool prepared;
277
278 /**
279 * @enabled:
280 *
281 * If true then the panel has been enabled.
282 */
283 bool enabled;
284
285 /**
286 * @container: Pointer to the private driver struct embedding this
287 * @struct drm_panel.
288 */
289 void *container;
290
291 /**
292 * @refcount: reference count of users referencing this panel.
293 */
294 struct kref refcount;
295};
296
297void *__devm_drm_panel_alloc(struct device *dev, size_t size, size_t offset,
298 const struct drm_panel_funcs *funcs,
299 int connector_type);
300
301/**
302 * devm_drm_panel_alloc - Allocate and initialize a refcounted panel.
303 *
304 * @dev: struct device of the panel device
305 * @type: the type of the struct which contains struct &drm_panel
306 * @member: the name of the &drm_panel within @type
307 * @funcs: callbacks for this panel
308 * @connector_type: the connector type (DRM_MODE_CONNECTOR_*) corresponding to
309 * the panel interface
310 *
311 * The reference count of the returned panel is initialized to 1. This
312 * reference will be automatically dropped via devm (by calling
313 * drm_panel_put()) when @dev is removed.
314 *
315 * Returns:
316 * Pointer to container structure embedding the panel, ERR_PTR on failure.
317 */
318#define devm_drm_panel_alloc(dev, type, member, funcs, connector_type) \
319 ((type *)__devm_drm_panel_alloc(dev, sizeof(type), \
320 offsetof(type, member), funcs, \
321 connector_type))
322
323struct drm_panel *drm_panel_get(struct drm_panel *panel);
324void drm_panel_put(struct drm_panel *panel);
325
326void drm_panel_add(struct drm_panel *panel);
327void drm_panel_remove(struct drm_panel *panel);
328int devm_drm_panel_add(struct device *dev, struct drm_panel *panel);
329
330void drm_panel_prepare(struct drm_panel *panel);
331void drm_panel_unprepare(struct drm_panel *panel);
332
333void drm_panel_enable(struct drm_panel *panel);
334void drm_panel_disable(struct drm_panel *panel);
335
336int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector);
337
338#if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
339struct drm_panel *of_drm_find_panel(const struct device_node *np);
340#else
341static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
342{
343 return ERR_PTR(-ENODEV);
344}
345#endif
346
347#if defined(CONFIG_DRM_PANEL)
348bool drm_is_panel_follower(struct device *dev);
349int drm_panel_add_follower(struct device *follower_dev,
350 struct drm_panel_follower *follower);
351void drm_panel_remove_follower(struct drm_panel_follower *follower);
352int devm_drm_panel_add_follower(struct device *follower_dev,
353 struct drm_panel_follower *follower);
354#else
355static inline bool drm_is_panel_follower(struct device *dev)
356{
357 return false;
358}
359
360static inline int drm_panel_add_follower(struct device *follower_dev,
361 struct drm_panel_follower *follower)
362{
363 return -ENODEV;
364}
365
366static inline void drm_panel_remove_follower(struct drm_panel_follower *follower) { }
367static inline int devm_drm_panel_add_follower(struct device *follower_dev,
368 struct drm_panel_follower *follower)
369{
370 return -ENODEV;
371}
372#endif
373
374#if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
375 (IS_MODULE(CONFIG_DRM) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
376int drm_panel_of_backlight(struct drm_panel *panel);
377#else
378static inline int drm_panel_of_backlight(struct drm_panel *panel)
379{
380 return 0;
381}
382#endif
383
384#endif