1 /*
2  * Copyright (C) 2012 Texas Instruments
3  * Author: Rob Clark <robdclark@gmail.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published by
7  * the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 /* LCDC DRM driver, based on da8xx-fb */
19 
20 #include <linux/component.h>
21 #include <linux/pinctrl/consumer.h>
22 #include <linux/suspend.h>
23 #include <drm/drm_atomic.h>
24 #include <drm/drm_atomic_helper.h>
25 
26 #include "tilcdc_drv.h"
27 #include "tilcdc_regs.h"
28 #include "tilcdc_tfp410.h"
29 #include "tilcdc_panel.h"
30 #include "tilcdc_external.h"
31 
32 #include "drm_fb_helper.h"
33 
34 static LIST_HEAD(module_list);
35 
36 static const u32 tilcdc_rev1_formats[] = { DRM_FORMAT_RGB565 };
37 
38 static const u32 tilcdc_straight_formats[] = { DRM_FORMAT_RGB565,
39 					       DRM_FORMAT_BGR888,
40 					       DRM_FORMAT_XBGR8888 };
41 
42 static const u32 tilcdc_crossed_formats[] = { DRM_FORMAT_BGR565,
43 					      DRM_FORMAT_RGB888,
44 					      DRM_FORMAT_XRGB8888 };
45 
46 static const u32 tilcdc_legacy_formats[] = { DRM_FORMAT_RGB565,
47 					     DRM_FORMAT_RGB888,
48 					     DRM_FORMAT_XRGB8888 };
49 
50 void tilcdc_module_init(struct tilcdc_module *mod, const char *name,
51 		const struct tilcdc_module_ops *funcs)
52 {
53 	mod->name = name;
54 	mod->funcs = funcs;
55 	INIT_LIST_HEAD(&mod->list);
56 	list_add(&mod->list, &module_list);
57 }
58 
59 void tilcdc_module_cleanup(struct tilcdc_module *mod)
60 {
61 	list_del(&mod->list);
62 }
63 
64 static struct of_device_id tilcdc_of_match[];
65 
66 static struct drm_framebuffer *tilcdc_fb_create(struct drm_device *dev,
67 		struct drm_file *file_priv, const struct drm_mode_fb_cmd2 *mode_cmd)
68 {
69 	return drm_fb_cma_create(dev, file_priv, mode_cmd);
70 }
71 
72 static void tilcdc_fb_output_poll_changed(struct drm_device *dev)
73 {
74 	struct tilcdc_drm_private *priv = dev->dev_private;
75 	drm_fbdev_cma_hotplug_event(priv->fbdev);
76 }
77 
78 static int tilcdc_atomic_check(struct drm_device *dev,
79 			       struct drm_atomic_state *state)
80 {
81 	int ret;
82 
83 	ret = drm_atomic_helper_check_modeset(dev, state);
84 	if (ret)
85 		return ret;
86 
87 	ret = drm_atomic_helper_check_planes(dev, state);
88 	if (ret)
89 		return ret;
90 
91 	/*
92 	 * tilcdc ->atomic_check can update ->mode_changed if pixel format
93 	 * changes, hence will we check modeset changes again.
94 	 */
95 	ret = drm_atomic_helper_check_modeset(dev, state);
96 	if (ret)
97 		return ret;
98 
99 	return ret;
100 }
101 
102 static int tilcdc_commit(struct drm_device *dev,
103 		  struct drm_atomic_state *state,
104 		  bool async)
105 {
106 	int ret;
107 
108 	ret = drm_atomic_helper_prepare_planes(dev, state);
109 	if (ret)
110 		return ret;
111 
112 	drm_atomic_helper_swap_state(state, true);
113 
114 	/*
115 	 * Everything below can be run asynchronously without the need to grab
116 	 * any modeset locks at all under one condition: It must be guaranteed
117 	 * that the asynchronous work has either been cancelled (if the driver
118 	 * supports it, which at least requires that the framebuffers get
119 	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
120 	 * before the new state gets committed on the software side with
121 	 * drm_atomic_helper_swap_state().
122 	 *
123 	 * This scheme allows new atomic state updates to be prepared and
124 	 * checked in parallel to the asynchronous completion of the previous
125 	 * update. Which is important since compositors need to figure out the
126 	 * composition of the next frame right after having submitted the
127 	 * current layout.
128 	 */
129 
130 	drm_atomic_helper_commit_modeset_disables(dev, state);
131 
132 	drm_atomic_helper_commit_planes(dev, state, 0);
133 
134 	drm_atomic_helper_commit_modeset_enables(dev, state);
135 
136 	drm_atomic_helper_wait_for_vblanks(dev, state);
137 
138 	drm_atomic_helper_cleanup_planes(dev, state);
139 
140 	return 0;
141 }
142 
143 static const struct drm_mode_config_funcs mode_config_funcs = {
144 	.fb_create = tilcdc_fb_create,
145 	.output_poll_changed = tilcdc_fb_output_poll_changed,
146 	.atomic_check = tilcdc_atomic_check,
147 	.atomic_commit = tilcdc_commit,
148 };
149 
150 static void modeset_init(struct drm_device *dev)
151 {
152 	struct tilcdc_drm_private *priv = dev->dev_private;
153 	struct tilcdc_module *mod;
154 
155 	list_for_each_entry(mod, &module_list, list) {
156 		DBG("loading module: %s", mod->name);
157 		mod->funcs->modeset_init(mod, dev);
158 	}
159 
160 	dev->mode_config.min_width = 0;
161 	dev->mode_config.min_height = 0;
162 	dev->mode_config.max_width = tilcdc_crtc_max_width(priv->crtc);
163 	dev->mode_config.max_height = 2048;
164 	dev->mode_config.funcs = &mode_config_funcs;
165 }
166 
167 #ifdef CONFIG_CPU_FREQ
168 static int cpufreq_transition(struct notifier_block *nb,
169 				     unsigned long val, void *data)
170 {
171 	struct tilcdc_drm_private *priv = container_of(nb,
172 			struct tilcdc_drm_private, freq_transition);
173 
174 	if (val == CPUFREQ_POSTCHANGE)
175 		tilcdc_crtc_update_clk(priv->crtc);
176 
177 	return 0;
178 }
179 #endif
180 
181 /*
182  * DRM operations:
183  */
184 
185 static void tilcdc_fini(struct drm_device *dev)
186 {
187 	struct tilcdc_drm_private *priv = dev->dev_private;
188 
189 	if (priv->crtc)
190 		tilcdc_crtc_shutdown(priv->crtc);
191 
192 	if (priv->is_registered)
193 		drm_dev_unregister(dev);
194 
195 	drm_kms_helper_poll_fini(dev);
196 
197 	if (priv->fbdev)
198 		drm_fbdev_cma_fini(priv->fbdev);
199 
200 	drm_irq_uninstall(dev);
201 	drm_mode_config_cleanup(dev);
202 	tilcdc_remove_external_device(dev);
203 
204 #ifdef CONFIG_CPU_FREQ
205 	if (priv->freq_transition.notifier_call)
206 		cpufreq_unregister_notifier(&priv->freq_transition,
207 					    CPUFREQ_TRANSITION_NOTIFIER);
208 #endif
209 
210 	if (priv->clk)
211 		clk_put(priv->clk);
212 
213 	if (priv->mmio)
214 		iounmap(priv->mmio);
215 
216 	if (priv->wq) {
217 		flush_workqueue(priv->wq);
218 		destroy_workqueue(priv->wq);
219 	}
220 
221 	dev->dev_private = NULL;
222 
223 	pm_runtime_disable(dev->dev);
224 
225 	drm_dev_unref(dev);
226 }
227 
228 static int tilcdc_init(struct drm_driver *ddrv, struct device *dev)
229 {
230 	struct drm_device *ddev;
231 	struct platform_device *pdev = to_platform_device(dev);
232 	struct device_node *node = dev->of_node;
233 	struct tilcdc_drm_private *priv;
234 	struct resource *res;
235 	u32 bpp = 0;
236 	int ret;
237 
238 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
239 	if (!priv) {
240 		dev_err(dev, "failed to allocate private data\n");
241 		return -ENOMEM;
242 	}
243 
244 	ddev = drm_dev_alloc(ddrv, dev);
245 	if (IS_ERR(ddev))
246 		return PTR_ERR(ddev);
247 
248 	ddev->platformdev = pdev;
249 	ddev->dev_private = priv;
250 	platform_set_drvdata(pdev, ddev);
251 	drm_mode_config_init(ddev);
252 
253 	priv->is_componentized =
254 		tilcdc_get_external_components(dev, NULL) > 0;
255 
256 	priv->wq = alloc_ordered_workqueue("tilcdc", 0);
257 	if (!priv->wq) {
258 		ret = -ENOMEM;
259 		goto init_failed;
260 	}
261 
262 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
263 	if (!res) {
264 		dev_err(dev, "failed to get memory resource\n");
265 		ret = -EINVAL;
266 		goto init_failed;
267 	}
268 
269 	priv->mmio = ioremap_nocache(res->start, resource_size(res));
270 	if (!priv->mmio) {
271 		dev_err(dev, "failed to ioremap\n");
272 		ret = -ENOMEM;
273 		goto init_failed;
274 	}
275 
276 	priv->clk = clk_get(dev, "fck");
277 	if (IS_ERR(priv->clk)) {
278 		dev_err(dev, "failed to get functional clock\n");
279 		ret = -ENODEV;
280 		goto init_failed;
281 	}
282 
283 #ifdef CONFIG_CPU_FREQ
284 	priv->freq_transition.notifier_call = cpufreq_transition;
285 	ret = cpufreq_register_notifier(&priv->freq_transition,
286 			CPUFREQ_TRANSITION_NOTIFIER);
287 	if (ret) {
288 		dev_err(dev, "failed to register cpufreq notifier\n");
289 		priv->freq_transition.notifier_call = NULL;
290 		goto init_failed;
291 	}
292 #endif
293 
294 	if (of_property_read_u32(node, "max-bandwidth", &priv->max_bandwidth))
295 		priv->max_bandwidth = TILCDC_DEFAULT_MAX_BANDWIDTH;
296 
297 	DBG("Maximum Bandwidth Value %d", priv->max_bandwidth);
298 
299 	if (of_property_read_u32(node, "max-width", &priv->max_width))
300 		priv->max_width = TILCDC_DEFAULT_MAX_WIDTH;
301 
302 	DBG("Maximum Horizontal Pixel Width Value %dpixels", priv->max_width);
303 
304 	if (of_property_read_u32(node, "max-pixelclock",
305 					&priv->max_pixelclock))
306 		priv->max_pixelclock = TILCDC_DEFAULT_MAX_PIXELCLOCK;
307 
308 	DBG("Maximum Pixel Clock Value %dKHz", priv->max_pixelclock);
309 
310 	pm_runtime_enable(dev);
311 
312 	/* Determine LCD IP Version */
313 	pm_runtime_get_sync(dev);
314 	switch (tilcdc_read(ddev, LCDC_PID_REG)) {
315 	case 0x4c100102:
316 		priv->rev = 1;
317 		break;
318 	case 0x4f200800:
319 	case 0x4f201000:
320 		priv->rev = 2;
321 		break;
322 	default:
323 		dev_warn(dev, "Unknown PID Reg value 0x%08x, "
324 			"defaulting to LCD revision 1\n",
325 			tilcdc_read(ddev, LCDC_PID_REG));
326 		priv->rev = 1;
327 		break;
328 	}
329 
330 	pm_runtime_put_sync(dev);
331 
332 	if (priv->rev == 1) {
333 		DBG("Revision 1 LCDC supports only RGB565 format");
334 		priv->pixelformats = tilcdc_rev1_formats;
335 		priv->num_pixelformats = ARRAY_SIZE(tilcdc_rev1_formats);
336 		bpp = 16;
337 	} else {
338 		const char *str = "\0";
339 
340 		of_property_read_string(node, "blue-and-red-wiring", &str);
341 		if (0 == strcmp(str, "crossed")) {
342 			DBG("Configured for crossed blue and red wires");
343 			priv->pixelformats = tilcdc_crossed_formats;
344 			priv->num_pixelformats =
345 				ARRAY_SIZE(tilcdc_crossed_formats);
346 			bpp = 32; /* Choose bpp with RGB support for fbdef */
347 		} else if (0 == strcmp(str, "straight")) {
348 			DBG("Configured for straight blue and red wires");
349 			priv->pixelformats = tilcdc_straight_formats;
350 			priv->num_pixelformats =
351 				ARRAY_SIZE(tilcdc_straight_formats);
352 			bpp = 16; /* Choose bpp with RGB support for fbdef */
353 		} else {
354 			DBG("Blue and red wiring '%s' unknown, use legacy mode",
355 			    str);
356 			priv->pixelformats = tilcdc_legacy_formats;
357 			priv->num_pixelformats =
358 				ARRAY_SIZE(tilcdc_legacy_formats);
359 			bpp = 16; /* This is just a guess */
360 		}
361 	}
362 
363 	ret = tilcdc_crtc_create(ddev);
364 	if (ret < 0) {
365 		dev_err(dev, "failed to create crtc\n");
366 		goto init_failed;
367 	}
368 	modeset_init(ddev);
369 
370 	if (priv->is_componentized) {
371 		ret = component_bind_all(dev, ddev);
372 		if (ret < 0)
373 			goto init_failed;
374 
375 		ret = tilcdc_add_component_encoder(ddev);
376 		if (ret < 0)
377 			goto init_failed;
378 	} else {
379 		ret = tilcdc_attach_external_device(ddev);
380 		if (ret)
381 			goto init_failed;
382 	}
383 
384 	if (!priv->external_connector &&
385 	    ((priv->num_encoders == 0) || (priv->num_connectors == 0))) {
386 		dev_err(dev, "no encoders/connectors found\n");
387 		ret = -ENXIO;
388 		goto init_failed;
389 	}
390 
391 	ret = drm_vblank_init(ddev, 1);
392 	if (ret < 0) {
393 		dev_err(dev, "failed to initialize vblank\n");
394 		goto init_failed;
395 	}
396 
397 	ret = drm_irq_install(ddev, platform_get_irq(pdev, 0));
398 	if (ret < 0) {
399 		dev_err(dev, "failed to install IRQ handler\n");
400 		goto init_failed;
401 	}
402 
403 	drm_mode_config_reset(ddev);
404 
405 	priv->fbdev = drm_fbdev_cma_init(ddev, bpp,
406 			ddev->mode_config.num_crtc,
407 			ddev->mode_config.num_connector);
408 	if (IS_ERR(priv->fbdev)) {
409 		ret = PTR_ERR(priv->fbdev);
410 		goto init_failed;
411 	}
412 
413 	drm_kms_helper_poll_init(ddev);
414 
415 	ret = drm_dev_register(ddev, 0);
416 	if (ret)
417 		goto init_failed;
418 
419 	priv->is_registered = true;
420 	return 0;
421 
422 init_failed:
423 	tilcdc_fini(ddev);
424 
425 	return ret;
426 }
427 
428 static void tilcdc_lastclose(struct drm_device *dev)
429 {
430 	struct tilcdc_drm_private *priv = dev->dev_private;
431 	drm_fbdev_cma_restore_mode(priv->fbdev);
432 }
433 
434 static irqreturn_t tilcdc_irq(int irq, void *arg)
435 {
436 	struct drm_device *dev = arg;
437 	struct tilcdc_drm_private *priv = dev->dev_private;
438 	return tilcdc_crtc_irq(priv->crtc);
439 }
440 
441 static int tilcdc_enable_vblank(struct drm_device *dev, unsigned int pipe)
442 {
443 	return 0;
444 }
445 
446 static void tilcdc_disable_vblank(struct drm_device *dev, unsigned int pipe)
447 {
448 	return;
449 }
450 
451 #if defined(CONFIG_DEBUG_FS)
452 static const struct {
453 	const char *name;
454 	uint8_t  rev;
455 	uint8_t  save;
456 	uint32_t reg;
457 } registers[] =		{
458 #define REG(rev, save, reg) { #reg, rev, save, reg }
459 		/* exists in revision 1: */
460 		REG(1, false, LCDC_PID_REG),
461 		REG(1, true,  LCDC_CTRL_REG),
462 		REG(1, false, LCDC_STAT_REG),
463 		REG(1, true,  LCDC_RASTER_CTRL_REG),
464 		REG(1, true,  LCDC_RASTER_TIMING_0_REG),
465 		REG(1, true,  LCDC_RASTER_TIMING_1_REG),
466 		REG(1, true,  LCDC_RASTER_TIMING_2_REG),
467 		REG(1, true,  LCDC_DMA_CTRL_REG),
468 		REG(1, true,  LCDC_DMA_FB_BASE_ADDR_0_REG),
469 		REG(1, true,  LCDC_DMA_FB_CEILING_ADDR_0_REG),
470 		REG(1, true,  LCDC_DMA_FB_BASE_ADDR_1_REG),
471 		REG(1, true,  LCDC_DMA_FB_CEILING_ADDR_1_REG),
472 		/* new in revision 2: */
473 		REG(2, false, LCDC_RAW_STAT_REG),
474 		REG(2, false, LCDC_MASKED_STAT_REG),
475 		REG(2, true, LCDC_INT_ENABLE_SET_REG),
476 		REG(2, false, LCDC_INT_ENABLE_CLR_REG),
477 		REG(2, false, LCDC_END_OF_INT_IND_REG),
478 		REG(2, true,  LCDC_CLK_ENABLE_REG),
479 #undef REG
480 };
481 
482 #endif
483 
484 #ifdef CONFIG_DEBUG_FS
485 static int tilcdc_regs_show(struct seq_file *m, void *arg)
486 {
487 	struct drm_info_node *node = (struct drm_info_node *) m->private;
488 	struct drm_device *dev = node->minor->dev;
489 	struct tilcdc_drm_private *priv = dev->dev_private;
490 	unsigned i;
491 
492 	pm_runtime_get_sync(dev->dev);
493 
494 	seq_printf(m, "revision: %d\n", priv->rev);
495 
496 	for (i = 0; i < ARRAY_SIZE(registers); i++)
497 		if (priv->rev >= registers[i].rev)
498 			seq_printf(m, "%s:\t %08x\n", registers[i].name,
499 					tilcdc_read(dev, registers[i].reg));
500 
501 	pm_runtime_put_sync(dev->dev);
502 
503 	return 0;
504 }
505 
506 static int tilcdc_mm_show(struct seq_file *m, void *arg)
507 {
508 	struct drm_info_node *node = (struct drm_info_node *) m->private;
509 	struct drm_device *dev = node->minor->dev;
510 	return drm_mm_dump_table(m, &dev->vma_offset_manager->vm_addr_space_mm);
511 }
512 
513 static struct drm_info_list tilcdc_debugfs_list[] = {
514 		{ "regs", tilcdc_regs_show, 0 },
515 		{ "mm",   tilcdc_mm_show,   0 },
516 		{ "fb",   drm_fb_cma_debugfs_show, 0 },
517 };
518 
519 static int tilcdc_debugfs_init(struct drm_minor *minor)
520 {
521 	struct drm_device *dev = minor->dev;
522 	struct tilcdc_module *mod;
523 	int ret;
524 
525 	ret = drm_debugfs_create_files(tilcdc_debugfs_list,
526 			ARRAY_SIZE(tilcdc_debugfs_list),
527 			minor->debugfs_root, minor);
528 
529 	list_for_each_entry(mod, &module_list, list)
530 		if (mod->funcs->debugfs_init)
531 			mod->funcs->debugfs_init(mod, minor);
532 
533 	if (ret) {
534 		dev_err(dev->dev, "could not install tilcdc_debugfs_list\n");
535 		return ret;
536 	}
537 
538 	return ret;
539 }
540 
541 static void tilcdc_debugfs_cleanup(struct drm_minor *minor)
542 {
543 	struct tilcdc_module *mod;
544 	drm_debugfs_remove_files(tilcdc_debugfs_list,
545 			ARRAY_SIZE(tilcdc_debugfs_list), minor);
546 
547 	list_for_each_entry(mod, &module_list, list)
548 		if (mod->funcs->debugfs_cleanup)
549 			mod->funcs->debugfs_cleanup(mod, minor);
550 }
551 #endif
552 
553 static const struct file_operations fops = {
554 	.owner              = THIS_MODULE,
555 	.open               = drm_open,
556 	.release            = drm_release,
557 	.unlocked_ioctl     = drm_ioctl,
558 	.compat_ioctl       = drm_compat_ioctl,
559 	.poll               = drm_poll,
560 	.read               = drm_read,
561 	.llseek             = no_llseek,
562 	.mmap               = drm_gem_cma_mmap,
563 };
564 
565 static struct drm_driver tilcdc_driver = {
566 	.driver_features    = (DRIVER_HAVE_IRQ | DRIVER_GEM | DRIVER_MODESET |
567 			       DRIVER_PRIME | DRIVER_ATOMIC),
568 	.lastclose          = tilcdc_lastclose,
569 	.irq_handler        = tilcdc_irq,
570 	.get_vblank_counter = drm_vblank_no_hw_counter,
571 	.enable_vblank      = tilcdc_enable_vblank,
572 	.disable_vblank     = tilcdc_disable_vblank,
573 	.gem_free_object_unlocked = drm_gem_cma_free_object,
574 	.gem_vm_ops         = &drm_gem_cma_vm_ops,
575 	.dumb_create        = drm_gem_cma_dumb_create,
576 	.dumb_map_offset    = drm_gem_cma_dumb_map_offset,
577 	.dumb_destroy       = drm_gem_dumb_destroy,
578 
579 	.prime_handle_to_fd	= drm_gem_prime_handle_to_fd,
580 	.prime_fd_to_handle	= drm_gem_prime_fd_to_handle,
581 	.gem_prime_import	= drm_gem_prime_import,
582 	.gem_prime_export	= drm_gem_prime_export,
583 	.gem_prime_get_sg_table	= drm_gem_cma_prime_get_sg_table,
584 	.gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
585 	.gem_prime_vmap		= drm_gem_cma_prime_vmap,
586 	.gem_prime_vunmap	= drm_gem_cma_prime_vunmap,
587 	.gem_prime_mmap		= drm_gem_cma_prime_mmap,
588 #ifdef CONFIG_DEBUG_FS
589 	.debugfs_init       = tilcdc_debugfs_init,
590 	.debugfs_cleanup    = tilcdc_debugfs_cleanup,
591 #endif
592 	.fops               = &fops,
593 	.name               = "tilcdc",
594 	.desc               = "TI LCD Controller DRM",
595 	.date               = "20121205",
596 	.major              = 1,
597 	.minor              = 0,
598 };
599 
600 /*
601  * Power management:
602  */
603 
604 #ifdef CONFIG_PM_SLEEP
605 static int tilcdc_pm_suspend(struct device *dev)
606 {
607 	struct drm_device *ddev = dev_get_drvdata(dev);
608 	struct tilcdc_drm_private *priv = ddev->dev_private;
609 
610 	priv->saved_state = drm_atomic_helper_suspend(ddev);
611 
612 	/* Select sleep pin state */
613 	pinctrl_pm_select_sleep_state(dev);
614 
615 	return 0;
616 }
617 
618 static int tilcdc_pm_resume(struct device *dev)
619 {
620 	struct drm_device *ddev = dev_get_drvdata(dev);
621 	struct tilcdc_drm_private *priv = ddev->dev_private;
622 	int ret = 0;
623 
624 	/* Select default pin state */
625 	pinctrl_pm_select_default_state(dev);
626 
627 	if (priv->saved_state)
628 		ret = drm_atomic_helper_resume(ddev, priv->saved_state);
629 
630 	return ret;
631 }
632 #endif
633 
634 static const struct dev_pm_ops tilcdc_pm_ops = {
635 	SET_SYSTEM_SLEEP_PM_OPS(tilcdc_pm_suspend, tilcdc_pm_resume)
636 };
637 
638 /*
639  * Platform driver:
640  */
641 static int tilcdc_bind(struct device *dev)
642 {
643 	return tilcdc_init(&tilcdc_driver, dev);
644 }
645 
646 static void tilcdc_unbind(struct device *dev)
647 {
648 	struct drm_device *ddev = dev_get_drvdata(dev);
649 
650 	/* Check if a subcomponent has already triggered the unloading. */
651 	if (!ddev->dev_private)
652 		return;
653 
654 	tilcdc_fini(dev_get_drvdata(dev));
655 }
656 
657 static const struct component_master_ops tilcdc_comp_ops = {
658 	.bind = tilcdc_bind,
659 	.unbind = tilcdc_unbind,
660 };
661 
662 static int tilcdc_pdev_probe(struct platform_device *pdev)
663 {
664 	struct component_match *match = NULL;
665 	int ret;
666 
667 	/* bail out early if no DT data: */
668 	if (!pdev->dev.of_node) {
669 		dev_err(&pdev->dev, "device-tree data is missing\n");
670 		return -ENXIO;
671 	}
672 
673 	ret = tilcdc_get_external_components(&pdev->dev, &match);
674 	if (ret < 0)
675 		return ret;
676 	else if (ret == 0)
677 		return tilcdc_init(&tilcdc_driver, &pdev->dev);
678 	else
679 		return component_master_add_with_match(&pdev->dev,
680 						       &tilcdc_comp_ops,
681 						       match);
682 }
683 
684 static int tilcdc_pdev_remove(struct platform_device *pdev)
685 {
686 	int ret;
687 
688 	ret = tilcdc_get_external_components(&pdev->dev, NULL);
689 	if (ret < 0)
690 		return ret;
691 	else if (ret == 0)
692 		tilcdc_fini(platform_get_drvdata(pdev));
693 	else
694 		component_master_del(&pdev->dev, &tilcdc_comp_ops);
695 
696 	return 0;
697 }
698 
699 static struct of_device_id tilcdc_of_match[] = {
700 		{ .compatible = "ti,am33xx-tilcdc", },
701 		{ .compatible = "ti,da850-tilcdc", },
702 		{ },
703 };
704 MODULE_DEVICE_TABLE(of, tilcdc_of_match);
705 
706 static struct platform_driver tilcdc_platform_driver = {
707 	.probe      = tilcdc_pdev_probe,
708 	.remove     = tilcdc_pdev_remove,
709 	.driver     = {
710 		.name   = "tilcdc",
711 		.pm     = &tilcdc_pm_ops,
712 		.of_match_table = tilcdc_of_match,
713 	},
714 };
715 
716 static int __init tilcdc_drm_init(void)
717 {
718 	DBG("init");
719 	tilcdc_tfp410_init();
720 	tilcdc_panel_init();
721 	return platform_driver_register(&tilcdc_platform_driver);
722 }
723 
724 static void __exit tilcdc_drm_fini(void)
725 {
726 	DBG("fini");
727 	platform_driver_unregister(&tilcdc_platform_driver);
728 	tilcdc_panel_fini();
729 	tilcdc_tfp410_fini();
730 }
731 
732 module_init(tilcdc_drm_init);
733 module_exit(tilcdc_drm_fini);
734 
735 MODULE_AUTHOR("Rob Clark <robdclark@gmail.com");
736 MODULE_DESCRIPTION("TI LCD Controller DRM Driver");
737 MODULE_LICENSE("GPL");
738