1 /*
2  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
3  * Authors:
4  *	Inki Dae <inki.dae@samsung.com>
5  *	Joonyoung Shim <jy0922.shim@samsung.com>
6  *	Seung-Woo Kim <sw0312.kim@samsung.com>
7  *
8  * This program is free software; you can redistribute  it and/or modify it
9  * under  the terms of  the GNU General  Public License as published by the
10  * Free Software Foundation;  either version 2 of the  License, or (at your
11  * option) any later version.
12  */
13 
14 #include <linux/pm_runtime.h>
15 #include <drm/drmP.h>
16 #include <drm/drm_atomic.h>
17 #include <drm/drm_atomic_helper.h>
18 #include <drm/drm_crtc_helper.h>
19 
20 #include <linux/component.h>
21 
22 #include <drm/exynos_drm.h>
23 
24 #include "exynos_drm_drv.h"
25 #include "exynos_drm_crtc.h"
26 #include "exynos_drm_fbdev.h"
27 #include "exynos_drm_fb.h"
28 #include "exynos_drm_gem.h"
29 #include "exynos_drm_plane.h"
30 #include "exynos_drm_vidi.h"
31 #include "exynos_drm_g2d.h"
32 #include "exynos_drm_ipp.h"
33 #include "exynos_drm_iommu.h"
34 
35 #define DRIVER_NAME	"exynos"
36 #define DRIVER_DESC	"Samsung SoC DRM"
37 #define DRIVER_DATE	"20110530"
38 #define DRIVER_MAJOR	1
39 #define DRIVER_MINOR	0
40 
41 struct exynos_atomic_commit {
42 	struct work_struct	work;
43 	struct drm_device	*dev;
44 	struct drm_atomic_state *state;
45 	u32			crtcs;
46 };
47 
48 static void exynos_atomic_commit_complete(struct exynos_atomic_commit *commit)
49 {
50 	struct drm_device *dev = commit->dev;
51 	struct exynos_drm_private *priv = dev->dev_private;
52 	struct drm_atomic_state *state = commit->state;
53 
54 	drm_atomic_helper_commit_modeset_disables(dev, state);
55 
56 	drm_atomic_helper_commit_modeset_enables(dev, state);
57 
58 	/*
59 	 * Exynos can't update planes with CRTCs and encoders disabled,
60 	 * its updates routines, specially for FIMD, requires the clocks
61 	 * to be enabled. So it is necessary to handle the modeset operations
62 	 * *before* the commit_planes() step, this way it will always
63 	 * have the relevant clocks enabled to perform the update.
64 	 */
65 
66 	drm_atomic_helper_commit_planes(dev, state, 0);
67 
68 	drm_atomic_helper_wait_for_vblanks(dev, state);
69 
70 	drm_atomic_helper_cleanup_planes(dev, state);
71 
72 	drm_atomic_state_put(state);
73 
74 	spin_lock(&priv->lock);
75 	priv->pending &= ~commit->crtcs;
76 	spin_unlock(&priv->lock);
77 
78 	wake_up_all(&priv->wait);
79 
80 	kfree(commit);
81 }
82 
83 static void exynos_drm_atomic_work(struct work_struct *work)
84 {
85 	struct exynos_atomic_commit *commit = container_of(work,
86 				struct exynos_atomic_commit, work);
87 
88 	exynos_atomic_commit_complete(commit);
89 }
90 
91 static struct device *exynos_drm_get_dma_device(void);
92 
93 static int exynos_drm_load(struct drm_device *dev, unsigned long flags)
94 {
95 	struct exynos_drm_private *private;
96 	struct drm_encoder *encoder;
97 	unsigned int clone_mask;
98 	int cnt, ret;
99 
100 	private = kzalloc(sizeof(struct exynos_drm_private), GFP_KERNEL);
101 	if (!private)
102 		return -ENOMEM;
103 
104 	init_waitqueue_head(&private->wait);
105 	spin_lock_init(&private->lock);
106 
107 	dev_set_drvdata(dev->dev, dev);
108 	dev->dev_private = (void *)private;
109 
110 	/* the first real CRTC device is used for all dma mapping operations */
111 	private->dma_dev = exynos_drm_get_dma_device();
112 	if (!private->dma_dev) {
113 		DRM_ERROR("no device found for DMA mapping operations.\n");
114 		ret = -ENODEV;
115 		goto err_free_private;
116 	}
117 	DRM_INFO("Exynos DRM: using %s device for DMA mapping operations\n",
118 		 dev_name(private->dma_dev));
119 
120 	/* create common IOMMU mapping for all devices attached to Exynos DRM */
121 	ret = drm_create_iommu_mapping(dev);
122 	if (ret < 0) {
123 		DRM_ERROR("failed to create iommu mapping.\n");
124 		goto err_free_private;
125 	}
126 
127 	drm_mode_config_init(dev);
128 
129 	exynos_drm_mode_config_init(dev);
130 
131 	/* setup possible_clones. */
132 	cnt = 0;
133 	clone_mask = 0;
134 	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head)
135 		clone_mask |= (1 << (cnt++));
136 
137 	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head)
138 		encoder->possible_clones = clone_mask;
139 
140 	platform_set_drvdata(dev->platformdev, dev);
141 
142 	/* Try to bind all sub drivers. */
143 	ret = component_bind_all(dev->dev, dev);
144 	if (ret)
145 		goto err_mode_config_cleanup;
146 
147 	ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
148 	if (ret)
149 		goto err_unbind_all;
150 
151 	/* Probe non kms sub drivers and virtual display driver. */
152 	ret = exynos_drm_device_subdrv_probe(dev);
153 	if (ret)
154 		goto err_cleanup_vblank;
155 
156 	drm_mode_config_reset(dev);
157 
158 	/*
159 	 * enable drm irq mode.
160 	 * - with irq_enabled = true, we can use the vblank feature.
161 	 *
162 	 * P.S. note that we wouldn't use drm irq handler but
163 	 *	just specific driver own one instead because
164 	 *	drm framework supports only one irq handler.
165 	 */
166 	dev->irq_enabled = true;
167 
168 	/* init kms poll for handling hpd */
169 	drm_kms_helper_poll_init(dev);
170 
171 	/* force connectors detection */
172 	drm_helper_hpd_irq_event(dev);
173 
174 	return 0;
175 
176 err_cleanup_vblank:
177 	drm_vblank_cleanup(dev);
178 err_unbind_all:
179 	component_unbind_all(dev->dev, dev);
180 err_mode_config_cleanup:
181 	drm_mode_config_cleanup(dev);
182 	drm_release_iommu_mapping(dev);
183 err_free_private:
184 	kfree(private);
185 
186 	return ret;
187 }
188 
189 static int exynos_drm_unload(struct drm_device *dev)
190 {
191 	exynos_drm_device_subdrv_remove(dev);
192 
193 	exynos_drm_fbdev_fini(dev);
194 	drm_kms_helper_poll_fini(dev);
195 
196 	drm_vblank_cleanup(dev);
197 	component_unbind_all(dev->dev, dev);
198 	drm_mode_config_cleanup(dev);
199 	drm_release_iommu_mapping(dev);
200 
201 	kfree(dev->dev_private);
202 	dev->dev_private = NULL;
203 
204 	return 0;
205 }
206 
207 static int commit_is_pending(struct exynos_drm_private *priv, u32 crtcs)
208 {
209 	bool pending;
210 
211 	spin_lock(&priv->lock);
212 	pending = priv->pending & crtcs;
213 	spin_unlock(&priv->lock);
214 
215 	return pending;
216 }
217 
218 int exynos_atomic_commit(struct drm_device *dev, struct drm_atomic_state *state,
219 			 bool nonblock)
220 {
221 	struct exynos_drm_private *priv = dev->dev_private;
222 	struct exynos_atomic_commit *commit;
223 	struct drm_crtc *crtc;
224 	struct drm_crtc_state *crtc_state;
225 	int i, ret;
226 
227 	commit = kzalloc(sizeof(*commit), GFP_KERNEL);
228 	if (!commit)
229 		return -ENOMEM;
230 
231 	ret = drm_atomic_helper_prepare_planes(dev, state);
232 	if (ret) {
233 		kfree(commit);
234 		return ret;
235 	}
236 
237 	/* This is the point of no return */
238 
239 	INIT_WORK(&commit->work, exynos_drm_atomic_work);
240 	commit->dev = dev;
241 	commit->state = state;
242 
243 	/* Wait until all affected CRTCs have completed previous commits and
244 	 * mark them as pending.
245 	 */
246 	for_each_crtc_in_state(state, crtc, crtc_state, i)
247 		commit->crtcs |= drm_crtc_mask(crtc);
248 
249 	wait_event(priv->wait, !commit_is_pending(priv, commit->crtcs));
250 
251 	spin_lock(&priv->lock);
252 	priv->pending |= commit->crtcs;
253 	spin_unlock(&priv->lock);
254 
255 	drm_atomic_helper_swap_state(state, true);
256 
257 	drm_atomic_state_get(state);
258 	if (nonblock)
259 		schedule_work(&commit->work);
260 	else
261 		exynos_atomic_commit_complete(commit);
262 
263 	return 0;
264 }
265 
266 int exynos_atomic_check(struct drm_device *dev,
267 			struct drm_atomic_state *state)
268 {
269 	int ret;
270 
271 	ret = drm_atomic_helper_check_modeset(dev, state);
272 	if (ret)
273 		return ret;
274 
275 	ret = drm_atomic_normalize_zpos(dev, state);
276 	if (ret)
277 		return ret;
278 
279 	ret = drm_atomic_helper_check_planes(dev, state);
280 	if (ret)
281 		return ret;
282 
283 	return ret;
284 }
285 
286 static int exynos_drm_open(struct drm_device *dev, struct drm_file *file)
287 {
288 	struct drm_exynos_file_private *file_priv;
289 	int ret;
290 
291 	file_priv = kzalloc(sizeof(*file_priv), GFP_KERNEL);
292 	if (!file_priv)
293 		return -ENOMEM;
294 
295 	file->driver_priv = file_priv;
296 
297 	ret = exynos_drm_subdrv_open(dev, file);
298 	if (ret)
299 		goto err_file_priv_free;
300 
301 	return ret;
302 
303 err_file_priv_free:
304 	kfree(file_priv);
305 	file->driver_priv = NULL;
306 	return ret;
307 }
308 
309 static void exynos_drm_preclose(struct drm_device *dev,
310 					struct drm_file *file)
311 {
312 	struct drm_crtc *crtc;
313 
314 	exynos_drm_subdrv_close(dev, file);
315 
316 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head)
317 		exynos_drm_crtc_cancel_page_flip(crtc, file);
318 }
319 
320 static void exynos_drm_postclose(struct drm_device *dev, struct drm_file *file)
321 {
322 	kfree(file->driver_priv);
323 	file->driver_priv = NULL;
324 }
325 
326 static void exynos_drm_lastclose(struct drm_device *dev)
327 {
328 	exynos_drm_fbdev_restore_mode(dev);
329 }
330 
331 static const struct vm_operations_struct exynos_drm_gem_vm_ops = {
332 	.fault = exynos_drm_gem_fault,
333 	.open = drm_gem_vm_open,
334 	.close = drm_gem_vm_close,
335 };
336 
337 static const struct drm_ioctl_desc exynos_ioctls[] = {
338 	DRM_IOCTL_DEF_DRV(EXYNOS_GEM_CREATE, exynos_drm_gem_create_ioctl,
339 			DRM_AUTH | DRM_RENDER_ALLOW),
340 	DRM_IOCTL_DEF_DRV(EXYNOS_GEM_MAP, exynos_drm_gem_map_ioctl,
341 			DRM_AUTH | DRM_RENDER_ALLOW),
342 	DRM_IOCTL_DEF_DRV(EXYNOS_GEM_GET, exynos_drm_gem_get_ioctl,
343 			DRM_RENDER_ALLOW),
344 	DRM_IOCTL_DEF_DRV(EXYNOS_VIDI_CONNECTION, vidi_connection_ioctl,
345 			DRM_AUTH),
346 	DRM_IOCTL_DEF_DRV(EXYNOS_G2D_GET_VER, exynos_g2d_get_ver_ioctl,
347 			DRM_AUTH | DRM_RENDER_ALLOW),
348 	DRM_IOCTL_DEF_DRV(EXYNOS_G2D_SET_CMDLIST, exynos_g2d_set_cmdlist_ioctl,
349 			DRM_AUTH | DRM_RENDER_ALLOW),
350 	DRM_IOCTL_DEF_DRV(EXYNOS_G2D_EXEC, exynos_g2d_exec_ioctl,
351 			DRM_AUTH | DRM_RENDER_ALLOW),
352 	DRM_IOCTL_DEF_DRV(EXYNOS_IPP_GET_PROPERTY, exynos_drm_ipp_get_property,
353 			DRM_AUTH | DRM_RENDER_ALLOW),
354 	DRM_IOCTL_DEF_DRV(EXYNOS_IPP_SET_PROPERTY, exynos_drm_ipp_set_property,
355 			DRM_AUTH | DRM_RENDER_ALLOW),
356 	DRM_IOCTL_DEF_DRV(EXYNOS_IPP_QUEUE_BUF, exynos_drm_ipp_queue_buf,
357 			DRM_AUTH | DRM_RENDER_ALLOW),
358 	DRM_IOCTL_DEF_DRV(EXYNOS_IPP_CMD_CTRL, exynos_drm_ipp_cmd_ctrl,
359 			DRM_AUTH | DRM_RENDER_ALLOW),
360 };
361 
362 static const struct file_operations exynos_drm_driver_fops = {
363 	.owner		= THIS_MODULE,
364 	.open		= drm_open,
365 	.mmap		= exynos_drm_gem_mmap,
366 	.poll		= drm_poll,
367 	.read		= drm_read,
368 	.unlocked_ioctl	= drm_ioctl,
369 	.compat_ioctl = drm_compat_ioctl,
370 	.release	= drm_release,
371 };
372 
373 static struct drm_driver exynos_drm_driver = {
374 	.driver_features	= DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME
375 				  | DRIVER_ATOMIC | DRIVER_RENDER,
376 	.load			= exynos_drm_load,
377 	.unload			= exynos_drm_unload,
378 	.open			= exynos_drm_open,
379 	.preclose		= exynos_drm_preclose,
380 	.lastclose		= exynos_drm_lastclose,
381 	.postclose		= exynos_drm_postclose,
382 	.get_vblank_counter	= drm_vblank_no_hw_counter,
383 	.enable_vblank		= exynos_drm_crtc_enable_vblank,
384 	.disable_vblank		= exynos_drm_crtc_disable_vblank,
385 	.gem_free_object_unlocked = exynos_drm_gem_free_object,
386 	.gem_vm_ops		= &exynos_drm_gem_vm_ops,
387 	.dumb_create		= exynos_drm_gem_dumb_create,
388 	.dumb_map_offset	= exynos_drm_gem_dumb_map_offset,
389 	.dumb_destroy		= drm_gem_dumb_destroy,
390 	.prime_handle_to_fd	= drm_gem_prime_handle_to_fd,
391 	.prime_fd_to_handle	= drm_gem_prime_fd_to_handle,
392 	.gem_prime_export	= drm_gem_prime_export,
393 	.gem_prime_import	= drm_gem_prime_import,
394 	.gem_prime_get_sg_table	= exynos_drm_gem_prime_get_sg_table,
395 	.gem_prime_import_sg_table	= exynos_drm_gem_prime_import_sg_table,
396 	.gem_prime_vmap		= exynos_drm_gem_prime_vmap,
397 	.gem_prime_vunmap	= exynos_drm_gem_prime_vunmap,
398 	.gem_prime_mmap		= exynos_drm_gem_prime_mmap,
399 	.ioctls			= exynos_ioctls,
400 	.num_ioctls		= ARRAY_SIZE(exynos_ioctls),
401 	.fops			= &exynos_drm_driver_fops,
402 	.name	= DRIVER_NAME,
403 	.desc	= DRIVER_DESC,
404 	.date	= DRIVER_DATE,
405 	.major	= DRIVER_MAJOR,
406 	.minor	= DRIVER_MINOR,
407 };
408 
409 #ifdef CONFIG_PM_SLEEP
410 static int exynos_drm_suspend(struct device *dev)
411 {
412 	struct drm_device *drm_dev = dev_get_drvdata(dev);
413 	struct drm_connector *connector;
414 
415 	if (pm_runtime_suspended(dev) || !drm_dev)
416 		return 0;
417 
418 	drm_modeset_lock_all(drm_dev);
419 	drm_for_each_connector(connector, drm_dev) {
420 		int old_dpms = connector->dpms;
421 
422 		if (connector->funcs->dpms)
423 			connector->funcs->dpms(connector, DRM_MODE_DPMS_OFF);
424 
425 		/* Set the old mode back to the connector for resume */
426 		connector->dpms = old_dpms;
427 	}
428 	drm_modeset_unlock_all(drm_dev);
429 
430 	return 0;
431 }
432 
433 static int exynos_drm_resume(struct device *dev)
434 {
435 	struct drm_device *drm_dev = dev_get_drvdata(dev);
436 	struct drm_connector *connector;
437 
438 	if (pm_runtime_suspended(dev) || !drm_dev)
439 		return 0;
440 
441 	drm_modeset_lock_all(drm_dev);
442 	drm_for_each_connector(connector, drm_dev) {
443 		if (connector->funcs->dpms) {
444 			int dpms = connector->dpms;
445 
446 			connector->dpms = DRM_MODE_DPMS_OFF;
447 			connector->funcs->dpms(connector, dpms);
448 		}
449 	}
450 	drm_modeset_unlock_all(drm_dev);
451 
452 	return 0;
453 }
454 #endif
455 
456 static const struct dev_pm_ops exynos_drm_pm_ops = {
457 	SET_SYSTEM_SLEEP_PM_OPS(exynos_drm_suspend, exynos_drm_resume)
458 };
459 
460 /* forward declaration */
461 static struct platform_driver exynos_drm_platform_driver;
462 
463 struct exynos_drm_driver_info {
464 	struct platform_driver *driver;
465 	unsigned int flags;
466 };
467 
468 #define DRM_COMPONENT_DRIVER	BIT(0)	/* supports component framework */
469 #define DRM_VIRTUAL_DEVICE	BIT(1)	/* create virtual platform device */
470 #define DRM_DMA_DEVICE		BIT(2)	/* can be used for dma allocations */
471 
472 #define DRV_PTR(drv, cond) (IS_ENABLED(cond) ? &drv : NULL)
473 
474 /*
475  * Connector drivers should not be placed before associated crtc drivers,
476  * because connector requires pipe number of its crtc during initialization.
477  */
478 static struct exynos_drm_driver_info exynos_drm_drivers[] = {
479 	{
480 		DRV_PTR(fimd_driver, CONFIG_DRM_EXYNOS_FIMD),
481 		DRM_COMPONENT_DRIVER | DRM_DMA_DEVICE
482 	}, {
483 		DRV_PTR(exynos5433_decon_driver, CONFIG_DRM_EXYNOS5433_DECON),
484 		DRM_COMPONENT_DRIVER | DRM_DMA_DEVICE
485 	}, {
486 		DRV_PTR(decon_driver, CONFIG_DRM_EXYNOS7_DECON),
487 		DRM_COMPONENT_DRIVER | DRM_DMA_DEVICE
488 	}, {
489 		DRV_PTR(mixer_driver, CONFIG_DRM_EXYNOS_MIXER),
490 		DRM_COMPONENT_DRIVER | DRM_DMA_DEVICE
491 	}, {
492 		DRV_PTR(mic_driver, CONFIG_DRM_EXYNOS_MIC),
493 		DRM_COMPONENT_DRIVER
494 	}, {
495 		DRV_PTR(dp_driver, CONFIG_DRM_EXYNOS_DP),
496 		DRM_COMPONENT_DRIVER
497 	}, {
498 		DRV_PTR(dsi_driver, CONFIG_DRM_EXYNOS_DSI),
499 		DRM_COMPONENT_DRIVER
500 	}, {
501 		DRV_PTR(hdmi_driver, CONFIG_DRM_EXYNOS_HDMI),
502 		DRM_COMPONENT_DRIVER
503 	}, {
504 		DRV_PTR(vidi_driver, CONFIG_DRM_EXYNOS_VIDI),
505 		DRM_COMPONENT_DRIVER | DRM_VIRTUAL_DEVICE
506 	}, {
507 		DRV_PTR(g2d_driver, CONFIG_DRM_EXYNOS_G2D),
508 	}, {
509 		DRV_PTR(fimc_driver, CONFIG_DRM_EXYNOS_FIMC),
510 	}, {
511 		DRV_PTR(rotator_driver, CONFIG_DRM_EXYNOS_ROTATOR),
512 	}, {
513 		DRV_PTR(gsc_driver, CONFIG_DRM_EXYNOS_GSC),
514 	}, {
515 		DRV_PTR(ipp_driver, CONFIG_DRM_EXYNOS_IPP),
516 		DRM_VIRTUAL_DEVICE
517 	}, {
518 		&exynos_drm_platform_driver,
519 		DRM_VIRTUAL_DEVICE
520 	}
521 };
522 
523 static int compare_dev(struct device *dev, void *data)
524 {
525 	return dev == (struct device *)data;
526 }
527 
528 static struct component_match *exynos_drm_match_add(struct device *dev)
529 {
530 	struct component_match *match = NULL;
531 	int i;
532 
533 	for (i = 0; i < ARRAY_SIZE(exynos_drm_drivers); ++i) {
534 		struct exynos_drm_driver_info *info = &exynos_drm_drivers[i];
535 		struct device *p = NULL, *d;
536 
537 		if (!info->driver || !(info->flags & DRM_COMPONENT_DRIVER))
538 			continue;
539 
540 		while ((d = bus_find_device(&platform_bus_type, p,
541 					    &info->driver->driver,
542 					    (void *)platform_bus_type.match))) {
543 			put_device(p);
544 			component_match_add(dev, &match, compare_dev, d);
545 			p = d;
546 		}
547 		put_device(p);
548 	}
549 
550 	return match ?: ERR_PTR(-ENODEV);
551 }
552 
553 static int exynos_drm_bind(struct device *dev)
554 {
555 	return drm_platform_init(&exynos_drm_driver, to_platform_device(dev));
556 }
557 
558 static void exynos_drm_unbind(struct device *dev)
559 {
560 	drm_put_dev(dev_get_drvdata(dev));
561 }
562 
563 static const struct component_master_ops exynos_drm_ops = {
564 	.bind		= exynos_drm_bind,
565 	.unbind		= exynos_drm_unbind,
566 };
567 
568 static int exynos_drm_platform_probe(struct platform_device *pdev)
569 {
570 	struct component_match *match;
571 
572 	pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
573 	exynos_drm_driver.num_ioctls = ARRAY_SIZE(exynos_ioctls);
574 
575 	match = exynos_drm_match_add(&pdev->dev);
576 	if (IS_ERR(match))
577 		return PTR_ERR(match);
578 
579 	return component_master_add_with_match(&pdev->dev, &exynos_drm_ops,
580 					       match);
581 }
582 
583 static int exynos_drm_platform_remove(struct platform_device *pdev)
584 {
585 	component_master_del(&pdev->dev, &exynos_drm_ops);
586 	return 0;
587 }
588 
589 static struct platform_driver exynos_drm_platform_driver = {
590 	.probe	= exynos_drm_platform_probe,
591 	.remove	= exynos_drm_platform_remove,
592 	.driver	= {
593 		.name	= "exynos-drm",
594 		.pm	= &exynos_drm_pm_ops,
595 	},
596 };
597 
598 static struct device *exynos_drm_get_dma_device(void)
599 {
600 	int i;
601 
602 	for (i = 0; i < ARRAY_SIZE(exynos_drm_drivers); ++i) {
603 		struct exynos_drm_driver_info *info = &exynos_drm_drivers[i];
604 		struct device *dev;
605 
606 		if (!info->driver || !(info->flags & DRM_DMA_DEVICE))
607 			continue;
608 
609 		while ((dev = bus_find_device(&platform_bus_type, NULL,
610 					    &info->driver->driver,
611 					    (void *)platform_bus_type.match))) {
612 			put_device(dev);
613 			return dev;
614 		}
615 	}
616 	return NULL;
617 }
618 
619 static void exynos_drm_unregister_devices(void)
620 {
621 	int i;
622 
623 	for (i = ARRAY_SIZE(exynos_drm_drivers) - 1; i >= 0; --i) {
624 		struct exynos_drm_driver_info *info = &exynos_drm_drivers[i];
625 		struct device *dev;
626 
627 		if (!info->driver || !(info->flags & DRM_VIRTUAL_DEVICE))
628 			continue;
629 
630 		while ((dev = bus_find_device(&platform_bus_type, NULL,
631 					    &info->driver->driver,
632 					    (void *)platform_bus_type.match))) {
633 			put_device(dev);
634 			platform_device_unregister(to_platform_device(dev));
635 		}
636 	}
637 }
638 
639 static int exynos_drm_register_devices(void)
640 {
641 	struct platform_device *pdev;
642 	int i;
643 
644 	for (i = 0; i < ARRAY_SIZE(exynos_drm_drivers); ++i) {
645 		struct exynos_drm_driver_info *info = &exynos_drm_drivers[i];
646 
647 		if (!info->driver || !(info->flags & DRM_VIRTUAL_DEVICE))
648 			continue;
649 
650 		pdev = platform_device_register_simple(
651 					info->driver->driver.name, -1, NULL, 0);
652 		if (IS_ERR(pdev))
653 			goto fail;
654 	}
655 
656 	return 0;
657 fail:
658 	exynos_drm_unregister_devices();
659 	return PTR_ERR(pdev);
660 }
661 
662 static void exynos_drm_unregister_drivers(void)
663 {
664 	int i;
665 
666 	for (i = ARRAY_SIZE(exynos_drm_drivers) - 1; i >= 0; --i) {
667 		struct exynos_drm_driver_info *info = &exynos_drm_drivers[i];
668 
669 		if (!info->driver)
670 			continue;
671 
672 		platform_driver_unregister(info->driver);
673 	}
674 }
675 
676 static int exynos_drm_register_drivers(void)
677 {
678 	int i, ret;
679 
680 	for (i = 0; i < ARRAY_SIZE(exynos_drm_drivers); ++i) {
681 		struct exynos_drm_driver_info *info = &exynos_drm_drivers[i];
682 
683 		if (!info->driver)
684 			continue;
685 
686 		ret = platform_driver_register(info->driver);
687 		if (ret)
688 			goto fail;
689 	}
690 	return 0;
691 fail:
692 	exynos_drm_unregister_drivers();
693 	return ret;
694 }
695 
696 static int exynos_drm_init(void)
697 {
698 	int ret;
699 
700 	ret = exynos_drm_register_devices();
701 	if (ret)
702 		return ret;
703 
704 	ret = exynos_drm_register_drivers();
705 	if (ret)
706 		goto err_unregister_pdevs;
707 
708 	return 0;
709 
710 err_unregister_pdevs:
711 	exynos_drm_unregister_devices();
712 
713 	return ret;
714 }
715 
716 static void exynos_drm_exit(void)
717 {
718 	exynos_drm_unregister_drivers();
719 	exynos_drm_unregister_devices();
720 }
721 
722 module_init(exynos_drm_init);
723 module_exit(exynos_drm_exit);
724 
725 MODULE_AUTHOR("Inki Dae <inki.dae@samsung.com>");
726 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
727 MODULE_AUTHOR("Seung-Woo Kim <sw0312.kim@samsung.com>");
728 MODULE_DESCRIPTION("Samsung SoC DRM Driver");
729 MODULE_LICENSE("GPL");
730