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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#include <linux/err.h>
25#include <linux/module.h>
26
27#include <drm/drm_crtc.h>
28#include <drm/drm_panel.h>
29
30static DEFINE_MUTEX(panel_lock);
31static LIST_HEAD(panel_list);
32
33void drm_panel_init(struct drm_panel *panel)
34{
35 INIT_LIST_HEAD(&panel->list);
36}
37EXPORT_SYMBOL(drm_panel_init);
38
39int drm_panel_add(struct drm_panel *panel)
40{
41 mutex_lock(&panel_lock);
42 list_add_tail(&panel->list, &panel_list);
43 mutex_unlock(&panel_lock);
44
45 return 0;
46}
47EXPORT_SYMBOL(drm_panel_add);
48
49void drm_panel_remove(struct drm_panel *panel)
50{
51 mutex_lock(&panel_lock);
52 list_del_init(&panel->list);
53 mutex_unlock(&panel_lock);
54}
55EXPORT_SYMBOL(drm_panel_remove);
56
57int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector)
58{
59 if (panel->connector)
60 return -EBUSY;
61
62 panel->connector = connector;
63 panel->drm = connector->dev;
64
65 return 0;
66}
67EXPORT_SYMBOL(drm_panel_attach);
68
69int drm_panel_detach(struct drm_panel *panel)
70{
71 panel->connector = NULL;
72 panel->drm = NULL;
73
74 return 0;
75}
76EXPORT_SYMBOL(drm_panel_detach);
77
78#ifdef CONFIG_OF
79struct drm_panel *of_drm_find_panel(struct device_node *np)
80{
81 struct drm_panel *panel;
82
83 mutex_lock(&panel_lock);
84
85 list_for_each_entry(panel, &panel_list, list) {
86 if (panel->dev->of_node == np) {
87 mutex_unlock(&panel_lock);
88 return panel;
89 }
90 }
91
92 mutex_unlock(&panel_lock);
93 return NULL;
94}
95EXPORT_SYMBOL(of_drm_find_panel);
96#endif
97
98MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
99MODULE_DESCRIPTION("DRM panel infrastructure");
100MODULE_LICENSE("GPL and additional rights");
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
32static DEFINE_MUTEX(panel_lock);
33static 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 */
57void drm_panel_init(struct drm_panel *panel, struct device *dev,
58 const struct drm_panel_funcs *funcs, int connector_type)
59{
60 INIT_LIST_HEAD(&panel->list);
61 INIT_LIST_HEAD(&panel->followers);
62 mutex_init(&panel->follower_lock);
63 panel->dev = dev;
64 panel->funcs = funcs;
65 panel->connector_type = connector_type;
66}
67EXPORT_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 */
76void drm_panel_add(struct drm_panel *panel)
77{
78 mutex_lock(&panel_lock);
79 list_add_tail(&panel->list, &panel_list);
80 mutex_unlock(&panel_lock);
81}
82EXPORT_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 */
90void drm_panel_remove(struct drm_panel *panel)
91{
92 mutex_lock(&panel_lock);
93 list_del_init(&panel->list);
94 mutex_unlock(&panel_lock);
95}
96EXPORT_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 */
108int drm_panel_prepare(struct drm_panel *panel)
109{
110 struct drm_panel_follower *follower;
111 int ret;
112
113 if (!panel)
114 return -EINVAL;
115
116 if (panel->prepared) {
117 dev_warn(panel->dev, "Skipping prepare of already prepared panel\n");
118 return 0;
119 }
120
121 mutex_lock(&panel->follower_lock);
122
123 if (panel->funcs && panel->funcs->prepare) {
124 ret = panel->funcs->prepare(panel);
125 if (ret < 0)
126 goto exit;
127 }
128 panel->prepared = true;
129
130 list_for_each_entry(follower, &panel->followers, list) {
131 ret = follower->funcs->panel_prepared(follower);
132 if (ret < 0)
133 dev_info(panel->dev, "%ps failed: %d\n",
134 follower->funcs->panel_prepared, ret);
135 }
136
137 ret = 0;
138exit:
139 mutex_unlock(&panel->follower_lock);
140
141 return ret;
142}
143EXPORT_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 */
156int drm_panel_unprepare(struct drm_panel *panel)
157{
158 struct drm_panel_follower *follower;
159 int ret;
160
161 if (!panel)
162 return -EINVAL;
163
164 if (!panel->prepared) {
165 dev_warn(panel->dev, "Skipping unprepare of already unprepared panel\n");
166 return 0;
167 }
168
169 mutex_lock(&panel->follower_lock);
170
171 list_for_each_entry(follower, &panel->followers, list) {
172 ret = follower->funcs->panel_unpreparing(follower);
173 if (ret < 0)
174 dev_info(panel->dev, "%ps failed: %d\n",
175 follower->funcs->panel_unpreparing, ret);
176 }
177
178 if (panel->funcs && panel->funcs->unprepare) {
179 ret = panel->funcs->unprepare(panel);
180 if (ret < 0)
181 goto exit;
182 }
183 panel->prepared = false;
184
185 ret = 0;
186exit:
187 mutex_unlock(&panel->follower_lock);
188
189 return ret;
190}
191EXPORT_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 */
203int drm_panel_enable(struct drm_panel *panel)
204{
205 int ret;
206
207 if (!panel)
208 return -EINVAL;
209
210 if (panel->enabled) {
211 dev_warn(panel->dev, "Skipping enable of already enabled panel\n");
212 return 0;
213 }
214
215 if (panel->funcs && panel->funcs->enable) {
216 ret = panel->funcs->enable(panel);
217 if (ret < 0)
218 return ret;
219 }
220 panel->enabled = true;
221
222 ret = backlight_enable(panel->backlight);
223 if (ret < 0)
224 DRM_DEV_INFO(panel->dev, "failed to enable backlight: %d\n",
225 ret);
226
227 return 0;
228}
229EXPORT_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 */
241int drm_panel_disable(struct drm_panel *panel)
242{
243 int ret;
244
245 if (!panel)
246 return -EINVAL;
247
248 if (!panel->enabled) {
249 dev_warn(panel->dev, "Skipping disable of already disabled panel\n");
250 return 0;
251 }
252
253 ret = backlight_disable(panel->backlight);
254 if (ret < 0)
255 DRM_DEV_INFO(panel->dev, "failed to disable backlight: %d\n",
256 ret);
257
258 if (panel->funcs && panel->funcs->disable) {
259 ret = panel->funcs->disable(panel);
260 if (ret < 0)
261 return ret;
262 }
263 panel->enabled = false;
264
265 return 0;
266}
267EXPORT_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 */
280int drm_panel_get_modes(struct drm_panel *panel,
281 struct drm_connector *connector)
282{
283 if (!panel)
284 return -EINVAL;
285
286 if (panel->funcs && panel->funcs->get_modes)
287 return panel->funcs->get_modes(panel, connector);
288
289 return -EOPNOTSUPP;
290}
291EXPORT_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 */
310struct 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}
329EXPORT_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 */
344int 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}
372EXPORT_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 */
386bool 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 return of_property_read_bool(dev->of_node, "panel");
394}
395EXPORT_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 */
417int 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 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}
450EXPORT_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 */
461void drm_panel_remove_follower(struct drm_panel_follower *follower)
462{
463 struct drm_panel *panel = follower->panel;
464 int ret;
465
466 mutex_lock(&panel->follower_lock);
467
468 if (panel->prepared) {
469 ret = follower->funcs->panel_unpreparing(follower);
470 if (ret < 0)
471 dev_info(panel->dev, "%ps failed: %d\n",
472 follower->funcs->panel_unpreparing, ret);
473 }
474 list_del_init(&follower->list);
475
476 mutex_unlock(&panel->follower_lock);
477
478 put_device(panel->dev);
479}
480EXPORT_SYMBOL(drm_panel_remove_follower);
481
482static 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 */
496int devm_drm_panel_add_follower(struct device *follower_dev,
497 struct drm_panel_follower *follower)
498{
499 int ret;
500
501 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}
508EXPORT_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 */
531int 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}
546EXPORT_SYMBOL(drm_panel_of_backlight);
547#endif
548
549MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
550MODULE_DESCRIPTION("DRM panel infrastructure");
551MODULE_LICENSE("GPL and additional rights");