1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015 MediaTek Inc.
4  * Author: YT SHEN <yt.shen@mediatek.com>
5  */
6 
7 #include <linux/component.h>
8 #include <linux/iommu.h>
9 #include <linux/module.h>
10 #include <linux/of_address.h>
11 #include <linux/of_platform.h>
12 #include <linux/pm_runtime.h>
13 #include <linux/soc/mediatek/mtk-mmsys.h>
14 #include <linux/dma-mapping.h>
15 
16 #include <drm/drm_atomic.h>
17 #include <drm/drm_atomic_helper.h>
18 #include <drm/drm_drv.h>
19 #include <drm/drm_fb_helper.h>
20 #include <drm/drm_fourcc.h>
21 #include <drm/drm_gem.h>
22 #include <drm/drm_gem_cma_helper.h>
23 #include <drm/drm_gem_framebuffer_helper.h>
24 #include <drm/drm_of.h>
25 #include <drm/drm_probe_helper.h>
26 #include <drm/drm_vblank.h>
27 
28 #include "mtk_drm_crtc.h"
29 #include "mtk_drm_ddp.h"
30 #include "mtk_drm_ddp.h"
31 #include "mtk_drm_ddp_comp.h"
32 #include "mtk_drm_drv.h"
33 #include "mtk_drm_gem.h"
34 
35 #define DRIVER_NAME "mediatek"
36 #define DRIVER_DESC "Mediatek SoC DRM"
37 #define DRIVER_DATE "20150513"
38 #define DRIVER_MAJOR 1
39 #define DRIVER_MINOR 0
40 
41 static const struct drm_mode_config_helper_funcs mtk_drm_mode_config_helpers = {
42 	.atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
43 };
44 
45 static struct drm_framebuffer *
46 mtk_drm_mode_fb_create(struct drm_device *dev,
47 		       struct drm_file *file,
48 		       const struct drm_mode_fb_cmd2 *cmd)
49 {
50 	const struct drm_format_info *info = drm_get_format_info(dev, cmd);
51 
52 	if (info->num_planes != 1)
53 		return ERR_PTR(-EINVAL);
54 
55 	return drm_gem_fb_create(dev, file, cmd);
56 }
57 
58 static const struct drm_mode_config_funcs mtk_drm_mode_config_funcs = {
59 	.fb_create = mtk_drm_mode_fb_create,
60 	.atomic_check = drm_atomic_helper_check,
61 	.atomic_commit = drm_atomic_helper_commit,
62 };
63 
64 static const enum mtk_ddp_comp_id mt2701_mtk_ddp_main[] = {
65 	DDP_COMPONENT_OVL0,
66 	DDP_COMPONENT_RDMA0,
67 	DDP_COMPONENT_COLOR0,
68 	DDP_COMPONENT_BLS,
69 	DDP_COMPONENT_DSI0,
70 };
71 
72 static const enum mtk_ddp_comp_id mt2701_mtk_ddp_ext[] = {
73 	DDP_COMPONENT_RDMA1,
74 	DDP_COMPONENT_DPI0,
75 };
76 
77 static const enum mtk_ddp_comp_id mt2712_mtk_ddp_main[] = {
78 	DDP_COMPONENT_OVL0,
79 	DDP_COMPONENT_COLOR0,
80 	DDP_COMPONENT_AAL0,
81 	DDP_COMPONENT_OD0,
82 	DDP_COMPONENT_RDMA0,
83 	DDP_COMPONENT_DPI0,
84 	DDP_COMPONENT_PWM0,
85 };
86 
87 static const enum mtk_ddp_comp_id mt2712_mtk_ddp_ext[] = {
88 	DDP_COMPONENT_OVL1,
89 	DDP_COMPONENT_COLOR1,
90 	DDP_COMPONENT_AAL1,
91 	DDP_COMPONENT_OD1,
92 	DDP_COMPONENT_RDMA1,
93 	DDP_COMPONENT_DPI1,
94 	DDP_COMPONENT_PWM1,
95 };
96 
97 static const enum mtk_ddp_comp_id mt2712_mtk_ddp_third[] = {
98 	DDP_COMPONENT_RDMA2,
99 	DDP_COMPONENT_DSI3,
100 	DDP_COMPONENT_PWM2,
101 };
102 
103 static const enum mtk_ddp_comp_id mt8173_mtk_ddp_main[] = {
104 	DDP_COMPONENT_OVL0,
105 	DDP_COMPONENT_COLOR0,
106 	DDP_COMPONENT_AAL0,
107 	DDP_COMPONENT_OD0,
108 	DDP_COMPONENT_RDMA0,
109 	DDP_COMPONENT_UFOE,
110 	DDP_COMPONENT_DSI0,
111 	DDP_COMPONENT_PWM0,
112 };
113 
114 static const enum mtk_ddp_comp_id mt8173_mtk_ddp_ext[] = {
115 	DDP_COMPONENT_OVL1,
116 	DDP_COMPONENT_COLOR1,
117 	DDP_COMPONENT_GAMMA,
118 	DDP_COMPONENT_RDMA1,
119 	DDP_COMPONENT_DPI0,
120 };
121 
122 static const struct mtk_mmsys_driver_data mt2701_mmsys_driver_data = {
123 	.main_path = mt2701_mtk_ddp_main,
124 	.main_len = ARRAY_SIZE(mt2701_mtk_ddp_main),
125 	.ext_path = mt2701_mtk_ddp_ext,
126 	.ext_len = ARRAY_SIZE(mt2701_mtk_ddp_ext),
127 	.shadow_register = true,
128 };
129 
130 static const struct mtk_mmsys_driver_data mt2712_mmsys_driver_data = {
131 	.main_path = mt2712_mtk_ddp_main,
132 	.main_len = ARRAY_SIZE(mt2712_mtk_ddp_main),
133 	.ext_path = mt2712_mtk_ddp_ext,
134 	.ext_len = ARRAY_SIZE(mt2712_mtk_ddp_ext),
135 	.third_path = mt2712_mtk_ddp_third,
136 	.third_len = ARRAY_SIZE(mt2712_mtk_ddp_third),
137 };
138 
139 static const struct mtk_mmsys_driver_data mt8173_mmsys_driver_data = {
140 	.main_path = mt8173_mtk_ddp_main,
141 	.main_len = ARRAY_SIZE(mt8173_mtk_ddp_main),
142 	.ext_path = mt8173_mtk_ddp_ext,
143 	.ext_len = ARRAY_SIZE(mt8173_mtk_ddp_ext),
144 };
145 
146 static int mtk_drm_kms_init(struct drm_device *drm)
147 {
148 	struct mtk_drm_private *private = drm->dev_private;
149 	struct platform_device *pdev;
150 	struct device_node *np;
151 	struct device *dma_dev;
152 	int ret;
153 
154 	if (!iommu_present(&platform_bus_type))
155 		return -EPROBE_DEFER;
156 
157 	pdev = of_find_device_by_node(private->mutex_node);
158 	if (!pdev) {
159 		dev_err(drm->dev, "Waiting for disp-mutex device %pOF\n",
160 			private->mutex_node);
161 		of_node_put(private->mutex_node);
162 		return -EPROBE_DEFER;
163 	}
164 	private->mutex_dev = &pdev->dev;
165 
166 	ret = drmm_mode_config_init(drm);
167 	if (ret)
168 		return ret;
169 
170 	drm->mode_config.min_width = 64;
171 	drm->mode_config.min_height = 64;
172 
173 	/*
174 	 * set max width and height as default value(4096x4096).
175 	 * this value would be used to check framebuffer size limitation
176 	 * at drm_mode_addfb().
177 	 */
178 	drm->mode_config.max_width = 4096;
179 	drm->mode_config.max_height = 4096;
180 	drm->mode_config.funcs = &mtk_drm_mode_config_funcs;
181 	drm->mode_config.helper_private = &mtk_drm_mode_config_helpers;
182 
183 	ret = component_bind_all(drm->dev, drm);
184 	if (ret)
185 		return ret;
186 
187 	/*
188 	 * We currently support two fixed data streams, each optional,
189 	 * and each statically assigned to a crtc:
190 	 * OVL0 -> COLOR0 -> AAL -> OD -> RDMA0 -> UFOE -> DSI0 ...
191 	 */
192 	ret = mtk_drm_crtc_create(drm, private->data->main_path,
193 				  private->data->main_len);
194 	if (ret < 0)
195 		goto err_component_unbind;
196 	/* ... and OVL1 -> COLOR1 -> GAMMA -> RDMA1 -> DPI0. */
197 	ret = mtk_drm_crtc_create(drm, private->data->ext_path,
198 				  private->data->ext_len);
199 	if (ret < 0)
200 		goto err_component_unbind;
201 
202 	ret = mtk_drm_crtc_create(drm, private->data->third_path,
203 				  private->data->third_len);
204 	if (ret < 0)
205 		goto err_component_unbind;
206 
207 	/* Use OVL device for all DMA memory allocations */
208 	np = private->comp_node[private->data->main_path[0]] ?:
209 	     private->comp_node[private->data->ext_path[0]];
210 	pdev = of_find_device_by_node(np);
211 	if (!pdev) {
212 		ret = -ENODEV;
213 		dev_err(drm->dev, "Need at least one OVL device\n");
214 		goto err_component_unbind;
215 	}
216 
217 	dma_dev = &pdev->dev;
218 	private->dma_dev = dma_dev;
219 
220 	/*
221 	 * Configure the DMA segment size to make sure we get contiguous IOVA
222 	 * when importing PRIME buffers.
223 	 */
224 	if (!dma_dev->dma_parms) {
225 		private->dma_parms_allocated = true;
226 		dma_dev->dma_parms =
227 			devm_kzalloc(drm->dev, sizeof(*dma_dev->dma_parms),
228 				     GFP_KERNEL);
229 	}
230 	if (!dma_dev->dma_parms) {
231 		ret = -ENOMEM;
232 		goto err_component_unbind;
233 	}
234 
235 	ret = dma_set_max_seg_size(dma_dev, (unsigned int)DMA_BIT_MASK(32));
236 	if (ret) {
237 		dev_err(dma_dev, "Failed to set DMA segment size\n");
238 		goto err_unset_dma_parms;
239 	}
240 
241 	/*
242 	 * We don't use the drm_irq_install() helpers provided by the DRM
243 	 * core, so we need to set this manually in order to allow the
244 	 * DRM_IOCTL_WAIT_VBLANK to operate correctly.
245 	 */
246 	drm->irq_enabled = true;
247 	ret = drm_vblank_init(drm, MAX_CRTC);
248 	if (ret < 0)
249 		goto err_unset_dma_parms;
250 
251 	drm_kms_helper_poll_init(drm);
252 	drm_mode_config_reset(drm);
253 
254 	return 0;
255 
256 err_unset_dma_parms:
257 	if (private->dma_parms_allocated)
258 		dma_dev->dma_parms = NULL;
259 err_component_unbind:
260 	component_unbind_all(drm->dev, drm);
261 
262 	return ret;
263 }
264 
265 static void mtk_drm_kms_deinit(struct drm_device *drm)
266 {
267 	struct mtk_drm_private *private = drm->dev_private;
268 
269 	drm_kms_helper_poll_fini(drm);
270 	drm_atomic_helper_shutdown(drm);
271 
272 	if (private->dma_parms_allocated)
273 		private->dma_dev->dma_parms = NULL;
274 
275 	component_unbind_all(drm->dev, drm);
276 }
277 
278 static const struct file_operations mtk_drm_fops = {
279 	.owner = THIS_MODULE,
280 	.open = drm_open,
281 	.release = drm_release,
282 	.unlocked_ioctl = drm_ioctl,
283 	.mmap = mtk_drm_gem_mmap,
284 	.poll = drm_poll,
285 	.read = drm_read,
286 	.compat_ioctl = drm_compat_ioctl,
287 };
288 
289 /*
290  * We need to override this because the device used to import the memory is
291  * not dev->dev, as drm_gem_prime_import() expects.
292  */
293 struct drm_gem_object *mtk_drm_gem_prime_import(struct drm_device *dev,
294 						struct dma_buf *dma_buf)
295 {
296 	struct mtk_drm_private *private = dev->dev_private;
297 
298 	return drm_gem_prime_import_dev(dev, dma_buf, private->dma_dev);
299 }
300 
301 static struct drm_driver mtk_drm_driver = {
302 	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
303 
304 	.gem_free_object_unlocked = mtk_drm_gem_free_object,
305 	.gem_vm_ops = &drm_gem_cma_vm_ops,
306 	.dumb_create = mtk_drm_gem_dumb_create,
307 
308 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
309 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
310 	.gem_prime_import = mtk_drm_gem_prime_import,
311 	.gem_prime_get_sg_table = mtk_gem_prime_get_sg_table,
312 	.gem_prime_import_sg_table = mtk_gem_prime_import_sg_table,
313 	.gem_prime_mmap = mtk_drm_gem_mmap_buf,
314 	.gem_prime_vmap = mtk_drm_gem_prime_vmap,
315 	.gem_prime_vunmap = mtk_drm_gem_prime_vunmap,
316 	.fops = &mtk_drm_fops,
317 
318 	.name = DRIVER_NAME,
319 	.desc = DRIVER_DESC,
320 	.date = DRIVER_DATE,
321 	.major = DRIVER_MAJOR,
322 	.minor = DRIVER_MINOR,
323 };
324 
325 static int compare_of(struct device *dev, void *data)
326 {
327 	return dev->of_node == data;
328 }
329 
330 static int mtk_drm_bind(struct device *dev)
331 {
332 	struct mtk_drm_private *private = dev_get_drvdata(dev);
333 	struct drm_device *drm;
334 	int ret;
335 
336 	drm = drm_dev_alloc(&mtk_drm_driver, dev);
337 	if (IS_ERR(drm))
338 		return PTR_ERR(drm);
339 
340 	drm->dev_private = private;
341 	private->drm = drm;
342 
343 	ret = mtk_drm_kms_init(drm);
344 	if (ret < 0)
345 		goto err_free;
346 
347 	ret = drm_dev_register(drm, 0);
348 	if (ret < 0)
349 		goto err_deinit;
350 
351 	drm_fbdev_generic_setup(drm, 32);
352 
353 	return 0;
354 
355 err_deinit:
356 	mtk_drm_kms_deinit(drm);
357 err_free:
358 	drm_dev_put(drm);
359 	return ret;
360 }
361 
362 static void mtk_drm_unbind(struct device *dev)
363 {
364 	struct mtk_drm_private *private = dev_get_drvdata(dev);
365 
366 	drm_dev_unregister(private->drm);
367 	mtk_drm_kms_deinit(private->drm);
368 	drm_dev_put(private->drm);
369 	private->num_pipes = 0;
370 	private->drm = NULL;
371 }
372 
373 static const struct component_master_ops mtk_drm_ops = {
374 	.bind		= mtk_drm_bind,
375 	.unbind		= mtk_drm_unbind,
376 };
377 
378 static const struct of_device_id mtk_ddp_comp_dt_ids[] = {
379 	{ .compatible = "mediatek,mt2701-disp-ovl",
380 	  .data = (void *)MTK_DISP_OVL },
381 	{ .compatible = "mediatek,mt8173-disp-ovl",
382 	  .data = (void *)MTK_DISP_OVL },
383 	{ .compatible = "mediatek,mt2701-disp-rdma",
384 	  .data = (void *)MTK_DISP_RDMA },
385 	{ .compatible = "mediatek,mt8173-disp-rdma",
386 	  .data = (void *)MTK_DISP_RDMA },
387 	{ .compatible = "mediatek,mt8173-disp-wdma",
388 	  .data = (void *)MTK_DISP_WDMA },
389 	{ .compatible = "mediatek,mt2701-disp-color",
390 	  .data = (void *)MTK_DISP_COLOR },
391 	{ .compatible = "mediatek,mt8173-disp-color",
392 	  .data = (void *)MTK_DISP_COLOR },
393 	{ .compatible = "mediatek,mt8173-disp-aal",
394 	  .data = (void *)MTK_DISP_AAL},
395 	{ .compatible = "mediatek,mt8173-disp-gamma",
396 	  .data = (void *)MTK_DISP_GAMMA, },
397 	{ .compatible = "mediatek,mt8173-disp-ufoe",
398 	  .data = (void *)MTK_DISP_UFOE },
399 	{ .compatible = "mediatek,mt2701-dsi",
400 	  .data = (void *)MTK_DSI },
401 	{ .compatible = "mediatek,mt8173-dsi",
402 	  .data = (void *)MTK_DSI },
403 	{ .compatible = "mediatek,mt2701-dpi",
404 	  .data = (void *)MTK_DPI },
405 	{ .compatible = "mediatek,mt8173-dpi",
406 	  .data = (void *)MTK_DPI },
407 	{ .compatible = "mediatek,mt2701-disp-mutex",
408 	  .data = (void *)MTK_DISP_MUTEX },
409 	{ .compatible = "mediatek,mt2712-disp-mutex",
410 	  .data = (void *)MTK_DISP_MUTEX },
411 	{ .compatible = "mediatek,mt8173-disp-mutex",
412 	  .data = (void *)MTK_DISP_MUTEX },
413 	{ .compatible = "mediatek,mt2701-disp-pwm",
414 	  .data = (void *)MTK_DISP_BLS },
415 	{ .compatible = "mediatek,mt8173-disp-pwm",
416 	  .data = (void *)MTK_DISP_PWM },
417 	{ .compatible = "mediatek,mt8173-disp-od",
418 	  .data = (void *)MTK_DISP_OD },
419 	{ }
420 };
421 
422 static const struct of_device_id mtk_drm_of_ids[] = {
423 	{ .compatible = "mediatek,mt2701-mmsys",
424 	  .data = &mt2701_mmsys_driver_data},
425 	{ .compatible = "mediatek,mt2712-mmsys",
426 	  .data = &mt2712_mmsys_driver_data},
427 	{ .compatible = "mediatek,mt8173-mmsys",
428 	  .data = &mt8173_mmsys_driver_data},
429 	{ }
430 };
431 
432 static int mtk_drm_probe(struct platform_device *pdev)
433 {
434 	struct device *dev = &pdev->dev;
435 	struct device_node *phandle = dev->parent->of_node;
436 	const struct of_device_id *of_id;
437 	struct mtk_drm_private *private;
438 	struct device_node *node;
439 	struct component_match *match = NULL;
440 	int ret;
441 	int i;
442 
443 	private = devm_kzalloc(dev, sizeof(*private), GFP_KERNEL);
444 	if (!private)
445 		return -ENOMEM;
446 
447 	private->mmsys_dev = dev->parent;
448 	if (!private->mmsys_dev) {
449 		dev_err(dev, "Failed to get MMSYS device\n");
450 		return -ENODEV;
451 	}
452 
453 	of_id = of_match_node(mtk_drm_of_ids, phandle);
454 	if (!of_id)
455 		return -ENODEV;
456 
457 	private->data = of_id->data;
458 
459 	/* Iterate over sibling DISP function blocks */
460 	for_each_child_of_node(phandle->parent, node) {
461 		const struct of_device_id *of_id;
462 		enum mtk_ddp_comp_type comp_type;
463 		int comp_id;
464 
465 		of_id = of_match_node(mtk_ddp_comp_dt_ids, node);
466 		if (!of_id)
467 			continue;
468 
469 		if (!of_device_is_available(node)) {
470 			dev_dbg(dev, "Skipping disabled component %pOF\n",
471 				node);
472 			continue;
473 		}
474 
475 		comp_type = (enum mtk_ddp_comp_type)of_id->data;
476 
477 		if (comp_type == MTK_DISP_MUTEX) {
478 			private->mutex_node = of_node_get(node);
479 			continue;
480 		}
481 
482 		comp_id = mtk_ddp_comp_get_id(node, comp_type);
483 		if (comp_id < 0) {
484 			dev_warn(dev, "Skipping unknown component %pOF\n",
485 				 node);
486 			continue;
487 		}
488 
489 		private->comp_node[comp_id] = of_node_get(node);
490 
491 		/*
492 		 * Currently only the COLOR, OVL, RDMA, DSI, and DPI blocks have
493 		 * separate component platform drivers and initialize their own
494 		 * DDP component structure. The others are initialized here.
495 		 */
496 		if (comp_type == MTK_DISP_COLOR ||
497 		    comp_type == MTK_DISP_OVL ||
498 		    comp_type == MTK_DISP_OVL_2L ||
499 		    comp_type == MTK_DISP_RDMA ||
500 		    comp_type == MTK_DSI ||
501 		    comp_type == MTK_DPI) {
502 			dev_info(dev, "Adding component match for %pOF\n",
503 				 node);
504 			drm_of_component_match_add(dev, &match, compare_of,
505 						   node);
506 		} else {
507 			struct mtk_ddp_comp *comp;
508 
509 			comp = devm_kzalloc(dev, sizeof(*comp), GFP_KERNEL);
510 			if (!comp) {
511 				ret = -ENOMEM;
512 				of_node_put(node);
513 				goto err_node;
514 			}
515 
516 			ret = mtk_ddp_comp_init(dev->parent, node, comp,
517 						comp_id, NULL);
518 			if (ret) {
519 				of_node_put(node);
520 				goto err_node;
521 			}
522 
523 			private->ddp_comp[comp_id] = comp;
524 		}
525 	}
526 
527 	if (!private->mutex_node) {
528 		dev_err(dev, "Failed to find disp-mutex node\n");
529 		ret = -ENODEV;
530 		goto err_node;
531 	}
532 
533 	pm_runtime_enable(dev);
534 
535 	platform_set_drvdata(pdev, private);
536 
537 	ret = component_master_add_with_match(dev, &mtk_drm_ops, match);
538 	if (ret)
539 		goto err_pm;
540 
541 	return 0;
542 
543 err_pm:
544 	pm_runtime_disable(dev);
545 err_node:
546 	of_node_put(private->mutex_node);
547 	for (i = 0; i < DDP_COMPONENT_ID_MAX; i++)
548 		of_node_put(private->comp_node[i]);
549 	return ret;
550 }
551 
552 static int mtk_drm_remove(struct platform_device *pdev)
553 {
554 	struct mtk_drm_private *private = platform_get_drvdata(pdev);
555 	int i;
556 
557 	component_master_del(&pdev->dev, &mtk_drm_ops);
558 	pm_runtime_disable(&pdev->dev);
559 	of_node_put(private->mutex_node);
560 	for (i = 0; i < DDP_COMPONENT_ID_MAX; i++)
561 		of_node_put(private->comp_node[i]);
562 
563 	return 0;
564 }
565 
566 #ifdef CONFIG_PM_SLEEP
567 static int mtk_drm_sys_suspend(struct device *dev)
568 {
569 	struct mtk_drm_private *private = dev_get_drvdata(dev);
570 	struct drm_device *drm = private->drm;
571 	int ret;
572 
573 	ret = drm_mode_config_helper_suspend(drm);
574 
575 	return ret;
576 }
577 
578 static int mtk_drm_sys_resume(struct device *dev)
579 {
580 	struct mtk_drm_private *private = dev_get_drvdata(dev);
581 	struct drm_device *drm = private->drm;
582 	int ret;
583 
584 	ret = drm_mode_config_helper_resume(drm);
585 
586 	return ret;
587 }
588 #endif
589 
590 static SIMPLE_DEV_PM_OPS(mtk_drm_pm_ops, mtk_drm_sys_suspend,
591 			 mtk_drm_sys_resume);
592 
593 static struct platform_driver mtk_drm_platform_driver = {
594 	.probe	= mtk_drm_probe,
595 	.remove	= mtk_drm_remove,
596 	.driver	= {
597 		.name	= "mediatek-drm",
598 		.pm     = &mtk_drm_pm_ops,
599 	},
600 };
601 
602 static struct platform_driver * const mtk_drm_drivers[] = {
603 	&mtk_ddp_driver,
604 	&mtk_disp_color_driver,
605 	&mtk_disp_ovl_driver,
606 	&mtk_disp_rdma_driver,
607 	&mtk_dpi_driver,
608 	&mtk_drm_platform_driver,
609 	&mtk_mipi_tx_driver,
610 	&mtk_dsi_driver,
611 };
612 
613 static int __init mtk_drm_init(void)
614 {
615 	return platform_register_drivers(mtk_drm_drivers,
616 					 ARRAY_SIZE(mtk_drm_drivers));
617 }
618 
619 static void __exit mtk_drm_exit(void)
620 {
621 	platform_unregister_drivers(mtk_drm_drivers,
622 				    ARRAY_SIZE(mtk_drm_drivers));
623 }
624 
625 module_init(mtk_drm_init);
626 module_exit(mtk_drm_exit);
627 
628 MODULE_AUTHOR("YT SHEN <yt.shen@mediatek.com>");
629 MODULE_DESCRIPTION("Mediatek SoC DRM driver");
630 MODULE_LICENSE("GPL v2");
631