Line data Source code
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 : #include <linux/backlight.h>
25 : #include <linux/err.h>
26 : #include <linux/module.h>
27 :
28 : #include <drm/drm_crtc.h>
29 : #include <drm/drm_panel.h>
30 : #include <drm/drm_print.h>
31 :
32 : static DEFINE_MUTEX(panel_lock);
33 : static LIST_HEAD(panel_list);
34 :
35 : /**
36 : * DOC: drm panel
37 : *
38 : * The DRM panel helpers allow drivers to register panel objects with a
39 : * central registry and provide functions to retrieve those panels in display
40 : * drivers.
41 : *
42 : * For easy integration into drivers using the &drm_bridge infrastructure please
43 : * take look at drm_panel_bridge_add() and devm_drm_panel_bridge_add().
44 : */
45 :
46 : /**
47 : * drm_panel_init - initialize a panel
48 : * @panel: DRM panel
49 : * @dev: parent device of the panel
50 : * @funcs: panel operations
51 : * @connector_type: the connector type (DRM_MODE_CONNECTOR_*) corresponding to
52 : * the panel interface
53 : *
54 : * Initialize the panel structure for subsequent registration with
55 : * drm_panel_add().
56 : */
57 0 : void drm_panel_init(struct drm_panel *panel, struct device *dev,
58 : const struct drm_panel_funcs *funcs, int connector_type)
59 : {
60 0 : INIT_LIST_HEAD(&panel->list);
61 0 : INIT_LIST_HEAD(&panel->followers);
62 0 : mutex_init(&panel->follower_lock);
63 0 : panel->dev = dev;
64 0 : panel->funcs = funcs;
65 0 : panel->connector_type = connector_type;
66 0 : }
67 : EXPORT_SYMBOL(drm_panel_init);
68 :
69 : /**
70 : * drm_panel_add - add a panel to the global registry
71 : * @panel: panel to add
72 : *
73 : * Add a panel to the global registry so that it can be looked up by display
74 : * drivers.
75 : */
76 0 : void drm_panel_add(struct drm_panel *panel)
77 : {
78 0 : mutex_lock(&panel_lock);
79 0 : list_add_tail(&panel->list, &panel_list);
80 0 : mutex_unlock(&panel_lock);
81 0 : }
82 : EXPORT_SYMBOL(drm_panel_add);
83 :
84 : /**
85 : * drm_panel_remove - remove a panel from the global registry
86 : * @panel: DRM panel
87 : *
88 : * Removes a panel from the global registry.
89 : */
90 0 : void drm_panel_remove(struct drm_panel *panel)
91 : {
92 0 : mutex_lock(&panel_lock);
93 0 : list_del_init(&panel->list);
94 0 : mutex_unlock(&panel_lock);
95 0 : }
96 : EXPORT_SYMBOL(drm_panel_remove);
97 :
98 : /**
99 : * drm_panel_prepare - power on a panel
100 : * @panel: DRM panel
101 : *
102 : * Calling this function will enable power and deassert any reset signals to
103 : * the panel. After this has completed it is possible to communicate with any
104 : * integrated circuitry via a command bus.
105 : *
106 : * Return: 0 on success or a negative error code on failure.
107 : */
108 0 : int drm_panel_prepare(struct drm_panel *panel)
109 : {
110 : struct drm_panel_follower *follower;
111 : int ret;
112 :
113 0 : if (!panel)
114 : return -EINVAL;
115 :
116 0 : if (panel->prepared) {
117 0 : dev_warn(panel->dev, "Skipping prepare of already prepared panel\n");
118 0 : return 0;
119 : }
120 :
121 0 : mutex_lock(&panel->follower_lock);
122 :
123 0 : if (panel->funcs && panel->funcs->prepare) {
124 0 : ret = panel->funcs->prepare(panel);
125 0 : if (ret < 0)
126 : goto exit;
127 : }
128 0 : panel->prepared = true;
129 :
130 0 : list_for_each_entry(follower, &panel->followers, list) {
131 0 : ret = follower->funcs->panel_prepared(follower);
132 0 : if (ret < 0)
133 0 : dev_info(panel->dev, "%ps failed: %d\n",
134 : follower->funcs->panel_prepared, ret);
135 : }
136 :
137 : ret = 0;
138 : exit:
139 0 : mutex_unlock(&panel->follower_lock);
140 :
141 0 : return ret;
142 : }
143 : EXPORT_SYMBOL(drm_panel_prepare);
144 :
145 : /**
146 : * drm_panel_unprepare - power off a panel
147 : * @panel: DRM panel
148 : *
149 : * Calling this function will completely power off a panel (assert the panel's
150 : * reset, turn off power supplies, ...). After this function has completed, it
151 : * is usually no longer possible to communicate with the panel until another
152 : * call to drm_panel_prepare().
153 : *
154 : * Return: 0 on success or a negative error code on failure.
155 : */
156 0 : int drm_panel_unprepare(struct drm_panel *panel)
157 : {
158 : struct drm_panel_follower *follower;
159 : int ret;
160 :
161 0 : if (!panel)
162 : return -EINVAL;
163 :
164 0 : if (!panel->prepared) {
165 0 : dev_warn(panel->dev, "Skipping unprepare of already unprepared panel\n");
166 0 : return 0;
167 : }
168 :
169 0 : mutex_lock(&panel->follower_lock);
170 :
171 0 : list_for_each_entry(follower, &panel->followers, list) {
172 0 : ret = follower->funcs->panel_unpreparing(follower);
173 0 : if (ret < 0)
174 0 : dev_info(panel->dev, "%ps failed: %d\n",
175 : follower->funcs->panel_unpreparing, ret);
176 : }
177 :
178 0 : if (panel->funcs && panel->funcs->unprepare) {
179 0 : ret = panel->funcs->unprepare(panel);
180 0 : if (ret < 0)
181 : goto exit;
182 : }
183 0 : panel->prepared = false;
184 :
185 0 : ret = 0;
186 : exit:
187 0 : mutex_unlock(&panel->follower_lock);
188 :
189 0 : return ret;
190 : }
191 : EXPORT_SYMBOL(drm_panel_unprepare);
192 :
193 : /**
194 : * drm_panel_enable - enable a panel
195 : * @panel: DRM panel
196 : *
197 : * Calling this function will cause the panel display drivers to be turned on
198 : * and the backlight to be enabled. Content will be visible on screen after
199 : * this call completes.
200 : *
201 : * Return: 0 on success or a negative error code on failure.
202 : */
203 0 : int drm_panel_enable(struct drm_panel *panel)
204 : {
205 : int ret;
206 :
207 0 : if (!panel)
208 : return -EINVAL;
209 :
210 0 : if (panel->enabled) {
211 0 : dev_warn(panel->dev, "Skipping enable of already enabled panel\n");
212 0 : return 0;
213 : }
214 :
215 0 : if (panel->funcs && panel->funcs->enable) {
216 0 : ret = panel->funcs->enable(panel);
217 0 : if (ret < 0)
218 : return ret;
219 : }
220 0 : panel->enabled = true;
221 :
222 0 : ret = backlight_enable(panel->backlight);
223 0 : if (ret < 0)
224 0 : DRM_DEV_INFO(panel->dev, "failed to enable backlight: %d\n",
225 : ret);
226 :
227 : return 0;
228 : }
229 : EXPORT_SYMBOL(drm_panel_enable);
230 :
231 : /**
232 : * drm_panel_disable - disable a panel
233 : * @panel: DRM panel
234 : *
235 : * This will typically turn off the panel's backlight or disable the display
236 : * drivers. For smart panels it should still be possible to communicate with
237 : * the integrated circuitry via any command bus after this call.
238 : *
239 : * Return: 0 on success or a negative error code on failure.
240 : */
241 0 : int drm_panel_disable(struct drm_panel *panel)
242 : {
243 : int ret;
244 :
245 0 : if (!panel)
246 : return -EINVAL;
247 :
248 0 : if (!panel->enabled) {
249 0 : dev_warn(panel->dev, "Skipping disable of already disabled panel\n");
250 0 : return 0;
251 : }
252 :
253 0 : ret = backlight_disable(panel->backlight);
254 0 : if (ret < 0)
255 0 : DRM_DEV_INFO(panel->dev, "failed to disable backlight: %d\n",
256 : ret);
257 :
258 0 : if (panel->funcs && panel->funcs->disable) {
259 0 : ret = panel->funcs->disable(panel);
260 0 : if (ret < 0)
261 : return ret;
262 : }
263 0 : panel->enabled = false;
264 :
265 0 : return 0;
266 : }
267 : EXPORT_SYMBOL(drm_panel_disable);
268 :
269 : /**
270 : * drm_panel_get_modes - probe the available display modes of a panel
271 : * @panel: DRM panel
272 : * @connector: DRM connector
273 : *
274 : * The modes probed from the panel are automatically added to the connector
275 : * that the panel is attached to.
276 : *
277 : * Return: The number of modes available from the panel on success or a
278 : * negative error code on failure.
279 : */
280 0 : int drm_panel_get_modes(struct drm_panel *panel,
281 : struct drm_connector *connector)
282 : {
283 0 : if (!panel)
284 : return -EINVAL;
285 :
286 0 : if (panel->funcs && panel->funcs->get_modes)
287 0 : return panel->funcs->get_modes(panel, connector);
288 :
289 : return -EOPNOTSUPP;
290 : }
291 : EXPORT_SYMBOL(drm_panel_get_modes);
292 :
293 : #ifdef CONFIG_OF
294 : /**
295 : * of_drm_find_panel - look up a panel using a device tree node
296 : * @np: device tree node of the panel
297 : *
298 : * Searches the set of registered panels for one that matches the given device
299 : * tree node. If a matching panel is found, return a pointer to it.
300 : *
301 : * Return: A pointer to the panel registered for the specified device tree
302 : * node or an ERR_PTR() if no panel matching the device tree node can be found.
303 : *
304 : * Possible error codes returned by this function:
305 : *
306 : * - EPROBE_DEFER: the panel device has not been probed yet, and the caller
307 : * should retry later
308 : * - ENODEV: the device is not available (status != "okay" or "ok")
309 : */
310 : struct drm_panel *of_drm_find_panel(const struct device_node *np)
311 : {
312 : struct drm_panel *panel;
313 :
314 : if (!of_device_is_available(np))
315 : return ERR_PTR(-ENODEV);
316 :
317 : mutex_lock(&panel_lock);
318 :
319 : list_for_each_entry(panel, &panel_list, list) {
320 : if (panel->dev->of_node == np) {
321 : mutex_unlock(&panel_lock);
322 : return panel;
323 : }
324 : }
325 :
326 : mutex_unlock(&panel_lock);
327 : return ERR_PTR(-EPROBE_DEFER);
328 : }
329 : EXPORT_SYMBOL(of_drm_find_panel);
330 :
331 : /**
332 : * of_drm_get_panel_orientation - look up the orientation of the panel through
333 : * the "rotation" binding from a device tree node
334 : * @np: device tree node of the panel
335 : * @orientation: orientation enum to be filled in
336 : *
337 : * Looks up the rotation of a panel in the device tree. The orientation of the
338 : * panel is expressed as a property name "rotation" in the device tree. The
339 : * rotation in the device tree is counter clockwise.
340 : *
341 : * Return: 0 when a valid rotation value (0, 90, 180, or 270) is read or the
342 : * rotation property doesn't exist. Return a negative error code on failure.
343 : */
344 : int of_drm_get_panel_orientation(const struct device_node *np,
345 : enum drm_panel_orientation *orientation)
346 : {
347 : int rotation, ret;
348 :
349 : ret = of_property_read_u32(np, "rotation", &rotation);
350 : if (ret == -EINVAL) {
351 : /* Don't return an error if there's no rotation property. */
352 : *orientation = DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
353 : return 0;
354 : }
355 :
356 : if (ret < 0)
357 : return ret;
358 :
359 : if (rotation == 0)
360 : *orientation = DRM_MODE_PANEL_ORIENTATION_NORMAL;
361 : else if (rotation == 90)
362 : *orientation = DRM_MODE_PANEL_ORIENTATION_RIGHT_UP;
363 : else if (rotation == 180)
364 : *orientation = DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP;
365 : else if (rotation == 270)
366 : *orientation = DRM_MODE_PANEL_ORIENTATION_LEFT_UP;
367 : else
368 : return -EINVAL;
369 :
370 : return 0;
371 : }
372 : EXPORT_SYMBOL(of_drm_get_panel_orientation);
373 : #endif
374 :
375 : /**
376 : * drm_is_panel_follower() - Check if the device is a panel follower
377 : * @dev: The 'struct device' to check
378 : *
379 : * This checks to see if a device needs to be power sequenced together with
380 : * a panel using the panel follower API.
381 : * At the moment panels can only be followed on device tree enabled systems.
382 : * The "panel" property of the follower points to the panel to be followed.
383 : *
384 : * Return: true if we should be power sequenced with a panel; false otherwise.
385 : */
386 0 : bool drm_is_panel_follower(struct device *dev)
387 : {
388 : /*
389 : * The "panel" property is actually a phandle, but for simplicity we
390 : * don't bother trying to parse it here. We just need to know if the
391 : * property is there.
392 : */
393 0 : return of_property_read_bool(dev->of_node, "panel");
394 : }
395 : EXPORT_SYMBOL(drm_is_panel_follower);
396 :
397 : /**
398 : * drm_panel_add_follower() - Register something to follow panel state.
399 : * @follower_dev: The 'struct device' for the follower.
400 : * @follower: The panel follower descriptor for the follower.
401 : *
402 : * A panel follower is called right after preparing the panel and right before
403 : * unpreparing the panel. It's primary intention is to power on an associated
404 : * touchscreen, though it could be used for any similar devices. Multiple
405 : * devices are allowed the follow the same panel.
406 : *
407 : * If a follower is added to a panel that's already been turned on, the
408 : * follower's prepare callback is called right away.
409 : *
410 : * At the moment panels can only be followed on device tree enabled systems.
411 : * The "panel" property of the follower points to the panel to be followed.
412 : *
413 : * Return: 0 or an error code. Note that -ENODEV means that we detected that
414 : * follower_dev is not actually following a panel. The caller may
415 : * choose to ignore this return value if following a panel is optional.
416 : */
417 0 : int drm_panel_add_follower(struct device *follower_dev,
418 : struct drm_panel_follower *follower)
419 : {
420 : struct device_node *panel_np;
421 : struct drm_panel *panel;
422 : int ret;
423 :
424 0 : panel_np = of_parse_phandle(follower_dev->of_node, "panel", 0);
425 : if (!panel_np)
426 : return -ENODEV;
427 :
428 : panel = of_drm_find_panel(panel_np);
429 : of_node_put(panel_np);
430 : if (IS_ERR(panel))
431 : return PTR_ERR(panel);
432 :
433 : get_device(panel->dev);
434 : follower->panel = panel;
435 :
436 : mutex_lock(&panel->follower_lock);
437 :
438 : list_add_tail(&follower->list, &panel->followers);
439 : if (panel->prepared) {
440 : ret = follower->funcs->panel_prepared(follower);
441 : if (ret < 0)
442 : dev_info(panel->dev, "%ps failed: %d\n",
443 : follower->funcs->panel_prepared, ret);
444 : }
445 :
446 : mutex_unlock(&panel->follower_lock);
447 :
448 : return 0;
449 : }
450 : EXPORT_SYMBOL(drm_panel_add_follower);
451 :
452 : /**
453 : * drm_panel_remove_follower() - Reverse drm_panel_add_follower().
454 : * @follower: The panel follower descriptor for the follower.
455 : *
456 : * Undo drm_panel_add_follower(). This includes calling the follower's
457 : * unprepare function if we're removed from a panel that's currently prepared.
458 : *
459 : * Return: 0 or an error code.
460 : */
461 0 : void drm_panel_remove_follower(struct drm_panel_follower *follower)
462 : {
463 0 : struct drm_panel *panel = follower->panel;
464 : int ret;
465 :
466 0 : mutex_lock(&panel->follower_lock);
467 :
468 0 : if (panel->prepared) {
469 0 : ret = follower->funcs->panel_unpreparing(follower);
470 0 : if (ret < 0)
471 0 : dev_info(panel->dev, "%ps failed: %d\n",
472 : follower->funcs->panel_unpreparing, ret);
473 : }
474 0 : list_del_init(&follower->list);
475 :
476 0 : mutex_unlock(&panel->follower_lock);
477 :
478 0 : put_device(panel->dev);
479 0 : }
480 : EXPORT_SYMBOL(drm_panel_remove_follower);
481 :
482 : static void drm_panel_remove_follower_void(void *follower)
483 : {
484 : drm_panel_remove_follower(follower);
485 : }
486 :
487 : /**
488 : * devm_drm_panel_add_follower() - devm version of drm_panel_add_follower()
489 : * @follower_dev: The 'struct device' for the follower.
490 : * @follower: The panel follower descriptor for the follower.
491 : *
492 : * Handles calling drm_panel_remove_follower() using devm on the follower_dev.
493 : *
494 : * Return: 0 or an error code.
495 : */
496 0 : int devm_drm_panel_add_follower(struct device *follower_dev,
497 : struct drm_panel_follower *follower)
498 : {
499 : int ret;
500 :
501 0 : ret = drm_panel_add_follower(follower_dev, follower);
502 : if (ret)
503 : return ret;
504 :
505 : return devm_add_action_or_reset(follower_dev,
506 : drm_panel_remove_follower_void, follower);
507 : }
508 : EXPORT_SYMBOL(devm_drm_panel_add_follower);
509 :
510 : #if IS_REACHABLE(CONFIG_BACKLIGHT_CLASS_DEVICE)
511 : /**
512 : * drm_panel_of_backlight - use backlight device node for backlight
513 : * @panel: DRM panel
514 : *
515 : * Use this function to enable backlight handling if your panel
516 : * uses device tree and has a backlight phandle.
517 : *
518 : * When the panel is enabled backlight will be enabled after a
519 : * successful call to &drm_panel_funcs.enable()
520 : *
521 : * When the panel is disabled backlight will be disabled before the
522 : * call to &drm_panel_funcs.disable().
523 : *
524 : * A typical implementation for a panel driver supporting device tree
525 : * will call this function at probe time. Backlight will then be handled
526 : * transparently without requiring any intervention from the driver.
527 : * drm_panel_of_backlight() must be called after the call to drm_panel_init().
528 : *
529 : * Return: 0 on success or a negative error code on failure.
530 : */
531 : int drm_panel_of_backlight(struct drm_panel *panel)
532 : {
533 : struct backlight_device *backlight;
534 :
535 : if (!panel || !panel->dev)
536 : return -EINVAL;
537 :
538 : backlight = devm_of_find_backlight(panel->dev);
539 :
540 : if (IS_ERR(backlight))
541 : return PTR_ERR(backlight);
542 :
543 : panel->backlight = backlight;
544 : return 0;
545 : }
546 : EXPORT_SYMBOL(drm_panel_of_backlight);
547 : #endif
548 :
549 : MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
550 : MODULE_DESCRIPTION("DRM panel infrastructure");
551 : MODULE_LICENSE("GPL and additional rights");
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