xref: /openbmc/linux/drivers/media/dvb-core/dvbdev.c (revision e5242c5f)
1 // SPDX-License-Identifier: LGPL-2.1-or-later
2 /*
3  * dvbdev.c
4  *
5  * Copyright (C) 2000 Ralph  Metzler <ralph@convergence.de>
6  *                  & Marcus Metzler <marcus@convergence.de>
7  *                    for convergence integrated media GmbH
8  */
9 
10 #define pr_fmt(fmt) "dvbdev: " fmt
11 
12 #include <linux/types.h>
13 #include <linux/errno.h>
14 #include <linux/string.h>
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/i2c.h>
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/device.h>
21 #include <linux/fs.h>
22 #include <linux/cdev.h>
23 #include <linux/mutex.h>
24 #include <media/dvbdev.h>
25 
26 /* Due to enum tuner_pad_index */
27 #include <media/tuner.h>
28 
29 static DEFINE_MUTEX(dvbdev_mutex);
30 static LIST_HEAD(dvbdevfops_list);
31 static int dvbdev_debug;
32 
33 module_param(dvbdev_debug, int, 0644);
34 MODULE_PARM_DESC(dvbdev_debug, "Turn on/off device debugging (default:off).");
35 
36 #define dprintk(fmt, arg...) do {					\
37 	if (dvbdev_debug)						\
38 		printk(KERN_DEBUG pr_fmt("%s: " fmt),			\
39 		       __func__, ##arg);				\
40 } while (0)
41 
42 static LIST_HEAD(dvb_adapter_list);
43 static DEFINE_MUTEX(dvbdev_register_lock);
44 
45 static const char * const dnames[] = {
46 	[DVB_DEVICE_VIDEO] =		"video",
47 	[DVB_DEVICE_AUDIO] =		"audio",
48 	[DVB_DEVICE_SEC] =		"sec",
49 	[DVB_DEVICE_FRONTEND] =		"frontend",
50 	[DVB_DEVICE_DEMUX] =		"demux",
51 	[DVB_DEVICE_DVR] =		"dvr",
52 	[DVB_DEVICE_CA] =		"ca",
53 	[DVB_DEVICE_NET] =		"net",
54 	[DVB_DEVICE_OSD] =		"osd"
55 };
56 
57 #ifdef CONFIG_DVB_DYNAMIC_MINORS
58 #define MAX_DVB_MINORS		256
59 #define DVB_MAX_IDS		MAX_DVB_MINORS
60 #else
61 #define DVB_MAX_IDS		4
62 
63 static const u8 minor_type[] = {
64 	[DVB_DEVICE_VIDEO]      = 0,
65 	[DVB_DEVICE_AUDIO]      = 1,
66 	[DVB_DEVICE_SEC]        = 2,
67 	[DVB_DEVICE_FRONTEND]   = 3,
68 	[DVB_DEVICE_DEMUX]      = 4,
69 	[DVB_DEVICE_DVR]        = 5,
70 	[DVB_DEVICE_CA]         = 6,
71 	[DVB_DEVICE_NET]        = 7,
72 	[DVB_DEVICE_OSD]        = 8,
73 };
74 
75 #define nums2minor(num, type, id) \
76 	(((num) << 6) | ((id) << 4) | minor_type[type])
77 
78 #define MAX_DVB_MINORS		(DVB_MAX_ADAPTERS * 64)
79 #endif
80 
81 static struct class *dvb_class;
82 
83 static struct dvb_device *dvb_minors[MAX_DVB_MINORS];
84 static DECLARE_RWSEM(minor_rwsem);
85 
86 static int dvb_device_open(struct inode *inode, struct file *file)
87 {
88 	struct dvb_device *dvbdev;
89 	unsigned int minor = iminor(inode);
90 
91 	if (minor >= MAX_DVB_MINORS)
92 		return -ENODEV;
93 
94 	mutex_lock(&dvbdev_mutex);
95 	down_read(&minor_rwsem);
96 
97 	dvbdev = dvb_minors[minor];
98 
99 	if (dvbdev && dvbdev->fops) {
100 		int err = 0;
101 		const struct file_operations *new_fops;
102 
103 		new_fops = fops_get(dvbdev->fops);
104 		if (!new_fops)
105 			goto fail;
106 		file->private_data = dvb_device_get(dvbdev);
107 		replace_fops(file, new_fops);
108 		if (file->f_op->open)
109 			err = file->f_op->open(inode, file);
110 		up_read(&minor_rwsem);
111 		mutex_unlock(&dvbdev_mutex);
112 		if (err)
113 			dvb_device_put(dvbdev);
114 		return err;
115 	}
116 fail:
117 	up_read(&minor_rwsem);
118 	mutex_unlock(&dvbdev_mutex);
119 	return -ENODEV;
120 }
121 
122 static const struct file_operations dvb_device_fops = {
123 	.owner =	THIS_MODULE,
124 	.open =		dvb_device_open,
125 	.llseek =	noop_llseek,
126 };
127 
128 static struct cdev dvb_device_cdev;
129 
130 int dvb_generic_open(struct inode *inode, struct file *file)
131 {
132 	struct dvb_device *dvbdev = file->private_data;
133 
134 	if (!dvbdev)
135 		return -ENODEV;
136 
137 	if (!dvbdev->users)
138 		return -EBUSY;
139 
140 	if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
141 		if (!dvbdev->readers)
142 			return -EBUSY;
143 		dvbdev->readers--;
144 	} else {
145 		if (!dvbdev->writers)
146 			return -EBUSY;
147 		dvbdev->writers--;
148 	}
149 
150 	dvbdev->users--;
151 	return 0;
152 }
153 EXPORT_SYMBOL(dvb_generic_open);
154 
155 int dvb_generic_release(struct inode *inode, struct file *file)
156 {
157 	struct dvb_device *dvbdev = file->private_data;
158 
159 	if (!dvbdev)
160 		return -ENODEV;
161 
162 	if ((file->f_flags & O_ACCMODE) == O_RDONLY)
163 		dvbdev->readers++;
164 	else
165 		dvbdev->writers++;
166 
167 	dvbdev->users++;
168 
169 	dvb_device_put(dvbdev);
170 
171 	return 0;
172 }
173 EXPORT_SYMBOL(dvb_generic_release);
174 
175 long dvb_generic_ioctl(struct file *file,
176 		       unsigned int cmd, unsigned long arg)
177 {
178 	struct dvb_device *dvbdev = file->private_data;
179 
180 	if (!dvbdev)
181 		return -ENODEV;
182 
183 	if (!dvbdev->kernel_ioctl)
184 		return -EINVAL;
185 
186 	return dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
187 }
188 EXPORT_SYMBOL(dvb_generic_ioctl);
189 
190 static int dvbdev_get_free_id(struct dvb_adapter *adap, int type)
191 {
192 	u32 id = 0;
193 
194 	while (id < DVB_MAX_IDS) {
195 		struct dvb_device *dev;
196 
197 		list_for_each_entry(dev, &adap->device_list, list_head)
198 			if (dev->type == type && dev->id == id)
199 				goto skip;
200 		return id;
201 skip:
202 		id++;
203 	}
204 	return -ENFILE;
205 }
206 
207 static void dvb_media_device_free(struct dvb_device *dvbdev)
208 {
209 #if defined(CONFIG_MEDIA_CONTROLLER_DVB)
210 	if (dvbdev->entity) {
211 		media_device_unregister_entity(dvbdev->entity);
212 		kfree(dvbdev->entity);
213 		kfree(dvbdev->pads);
214 		dvbdev->entity = NULL;
215 		dvbdev->pads = NULL;
216 	}
217 
218 	if (dvbdev->tsout_entity) {
219 		int i;
220 
221 		for (i = 0; i < dvbdev->tsout_num_entities; i++) {
222 			media_device_unregister_entity(&dvbdev->tsout_entity[i]);
223 			kfree(dvbdev->tsout_entity[i].name);
224 		}
225 		kfree(dvbdev->tsout_entity);
226 		kfree(dvbdev->tsout_pads);
227 		dvbdev->tsout_entity = NULL;
228 		dvbdev->tsout_pads = NULL;
229 
230 		dvbdev->tsout_num_entities = 0;
231 	}
232 
233 	if (dvbdev->intf_devnode) {
234 		media_devnode_remove(dvbdev->intf_devnode);
235 		dvbdev->intf_devnode = NULL;
236 	}
237 
238 	if (dvbdev->adapter->conn) {
239 		media_device_unregister_entity(dvbdev->adapter->conn);
240 		kfree(dvbdev->adapter->conn);
241 		dvbdev->adapter->conn = NULL;
242 		kfree(dvbdev->adapter->conn_pads);
243 		dvbdev->adapter->conn_pads = NULL;
244 	}
245 #endif
246 }
247 
248 #if defined(CONFIG_MEDIA_CONTROLLER_DVB)
249 static int dvb_create_tsout_entity(struct dvb_device *dvbdev,
250 				   const char *name, int npads)
251 {
252 	int i;
253 
254 	dvbdev->tsout_pads = kcalloc(npads, sizeof(*dvbdev->tsout_pads),
255 				     GFP_KERNEL);
256 	if (!dvbdev->tsout_pads)
257 		return -ENOMEM;
258 
259 	dvbdev->tsout_entity = kcalloc(npads, sizeof(*dvbdev->tsout_entity),
260 				       GFP_KERNEL);
261 	if (!dvbdev->tsout_entity)
262 		return -ENOMEM;
263 
264 	dvbdev->tsout_num_entities = npads;
265 
266 	for (i = 0; i < npads; i++) {
267 		struct media_pad *pads = &dvbdev->tsout_pads[i];
268 		struct media_entity *entity = &dvbdev->tsout_entity[i];
269 		int ret;
270 
271 		entity->name = kasprintf(GFP_KERNEL, "%s #%d", name, i);
272 		if (!entity->name)
273 			return -ENOMEM;
274 
275 		entity->function = MEDIA_ENT_F_IO_DTV;
276 		pads->flags = MEDIA_PAD_FL_SINK;
277 
278 		ret = media_entity_pads_init(entity, 1, pads);
279 		if (ret < 0)
280 			return ret;
281 
282 		ret = media_device_register_entity(dvbdev->adapter->mdev,
283 						   entity);
284 		if (ret < 0)
285 			return ret;
286 	}
287 	return 0;
288 }
289 
290 #define DEMUX_TSOUT	"demux-tsout"
291 #define DVR_TSOUT	"dvr-tsout"
292 
293 static int dvb_create_media_entity(struct dvb_device *dvbdev,
294 				   int type, int demux_sink_pads)
295 {
296 	int i, ret, npads;
297 
298 	switch (type) {
299 	case DVB_DEVICE_FRONTEND:
300 		npads = 2;
301 		break;
302 	case DVB_DEVICE_DVR:
303 		ret = dvb_create_tsout_entity(dvbdev, DVR_TSOUT,
304 					      demux_sink_pads);
305 		return ret;
306 	case DVB_DEVICE_DEMUX:
307 		npads = 1 + demux_sink_pads;
308 		ret = dvb_create_tsout_entity(dvbdev, DEMUX_TSOUT,
309 					      demux_sink_pads);
310 		if (ret < 0)
311 			return ret;
312 		break;
313 	case DVB_DEVICE_CA:
314 		npads = 2;
315 		break;
316 	case DVB_DEVICE_NET:
317 		/*
318 		 * We should be creating entities for the MPE/ULE
319 		 * decapsulation hardware (or software implementation).
320 		 *
321 		 * However, the number of for the MPE/ULE decaps may not be
322 		 * fixed. As we don't have yet dynamic support for PADs at
323 		 * the Media Controller, let's not create the decap
324 		 * entities yet.
325 		 */
326 		return 0;
327 	default:
328 		return 0;
329 	}
330 
331 	dvbdev->entity = kzalloc(sizeof(*dvbdev->entity), GFP_KERNEL);
332 	if (!dvbdev->entity)
333 		return -ENOMEM;
334 
335 	dvbdev->entity->name = dvbdev->name;
336 
337 	if (npads) {
338 		dvbdev->pads = kcalloc(npads, sizeof(*dvbdev->pads),
339 				       GFP_KERNEL);
340 		if (!dvbdev->pads) {
341 			kfree(dvbdev->entity);
342 			dvbdev->entity = NULL;
343 			return -ENOMEM;
344 		}
345 	}
346 
347 	switch (type) {
348 	case DVB_DEVICE_FRONTEND:
349 		dvbdev->entity->function = MEDIA_ENT_F_DTV_DEMOD;
350 		dvbdev->pads[0].flags = MEDIA_PAD_FL_SINK;
351 		dvbdev->pads[1].flags = MEDIA_PAD_FL_SOURCE;
352 		break;
353 	case DVB_DEVICE_DEMUX:
354 		dvbdev->entity->function = MEDIA_ENT_F_TS_DEMUX;
355 		dvbdev->pads[0].flags = MEDIA_PAD_FL_SINK;
356 		for (i = 1; i < npads; i++)
357 			dvbdev->pads[i].flags = MEDIA_PAD_FL_SOURCE;
358 		break;
359 	case DVB_DEVICE_CA:
360 		dvbdev->entity->function = MEDIA_ENT_F_DTV_CA;
361 		dvbdev->pads[0].flags = MEDIA_PAD_FL_SINK;
362 		dvbdev->pads[1].flags = MEDIA_PAD_FL_SOURCE;
363 		break;
364 	default:
365 		/* Should never happen, as the first switch prevents it */
366 		kfree(dvbdev->entity);
367 		kfree(dvbdev->pads);
368 		dvbdev->entity = NULL;
369 		dvbdev->pads = NULL;
370 		return 0;
371 	}
372 
373 	if (npads) {
374 		ret = media_entity_pads_init(dvbdev->entity, npads, dvbdev->pads);
375 		if (ret)
376 			return ret;
377 	}
378 	ret = media_device_register_entity(dvbdev->adapter->mdev,
379 					   dvbdev->entity);
380 	if (ret)
381 		return ret;
382 
383 	pr_info("%s: media entity '%s' registered.\n",
384 		__func__, dvbdev->entity->name);
385 
386 	return 0;
387 }
388 #endif
389 
390 static int dvb_register_media_device(struct dvb_device *dvbdev,
391 				     int type, int minor,
392 				     unsigned int demux_sink_pads)
393 {
394 #if defined(CONFIG_MEDIA_CONTROLLER_DVB)
395 	struct media_link *link;
396 	u32 intf_type;
397 	int ret;
398 
399 	if (!dvbdev->adapter->mdev)
400 		return 0;
401 
402 	ret = dvb_create_media_entity(dvbdev, type, demux_sink_pads);
403 	if (ret)
404 		return ret;
405 
406 	switch (type) {
407 	case DVB_DEVICE_FRONTEND:
408 		intf_type = MEDIA_INTF_T_DVB_FE;
409 		break;
410 	case DVB_DEVICE_DEMUX:
411 		intf_type = MEDIA_INTF_T_DVB_DEMUX;
412 		break;
413 	case DVB_DEVICE_DVR:
414 		intf_type = MEDIA_INTF_T_DVB_DVR;
415 		break;
416 	case DVB_DEVICE_CA:
417 		intf_type = MEDIA_INTF_T_DVB_CA;
418 		break;
419 	case DVB_DEVICE_NET:
420 		intf_type = MEDIA_INTF_T_DVB_NET;
421 		break;
422 	default:
423 		return 0;
424 	}
425 
426 	dvbdev->intf_devnode = media_devnode_create(dvbdev->adapter->mdev,
427 						    intf_type, 0,
428 						    DVB_MAJOR, minor);
429 
430 	if (!dvbdev->intf_devnode)
431 		return -ENOMEM;
432 
433 	/*
434 	 * Create the "obvious" link, e. g. the ones that represent
435 	 * a direct association between an interface and an entity.
436 	 * Other links should be created elsewhere, like:
437 	 *		DVB FE intf    -> tuner
438 	 *		DVB demux intf -> dvr
439 	 */
440 
441 	if (!dvbdev->entity)
442 		return 0;
443 
444 	link = media_create_intf_link(dvbdev->entity,
445 				      &dvbdev->intf_devnode->intf,
446 				      MEDIA_LNK_FL_ENABLED |
447 				      MEDIA_LNK_FL_IMMUTABLE);
448 	if (!link)
449 		return -ENOMEM;
450 #endif
451 	return 0;
452 }
453 
454 int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
455 			const struct dvb_device *template, void *priv,
456 			enum dvb_device_type type, int demux_sink_pads)
457 {
458 	struct dvb_device *dvbdev;
459 	struct file_operations *dvbdevfops = NULL;
460 	struct dvbdevfops_node *node = NULL, *new_node = NULL;
461 	struct device *clsdev;
462 	int minor;
463 	int id, ret;
464 
465 	mutex_lock(&dvbdev_register_lock);
466 
467 	id = dvbdev_get_free_id(adap, type);
468 	if (id < 0) {
469 		mutex_unlock(&dvbdev_register_lock);
470 		*pdvbdev = NULL;
471 		pr_err("%s: couldn't find free device id\n", __func__);
472 		return -ENFILE;
473 	}
474 
475 	*pdvbdev = dvbdev = kzalloc(sizeof(*dvbdev), GFP_KERNEL);
476 	if (!dvbdev) {
477 		mutex_unlock(&dvbdev_register_lock);
478 		return -ENOMEM;
479 	}
480 
481 	/*
482 	 * When a device of the same type is probe()d more than once,
483 	 * the first allocated fops are used. This prevents memory leaks
484 	 * that can occur when the same device is probe()d repeatedly.
485 	 */
486 	list_for_each_entry(node, &dvbdevfops_list, list_head) {
487 		if (node->fops->owner == adap->module &&
488 		    node->type == type && node->template == template) {
489 			dvbdevfops = node->fops;
490 			break;
491 		}
492 	}
493 
494 	if (!dvbdevfops) {
495 		dvbdevfops = kmemdup(template->fops, sizeof(*dvbdevfops), GFP_KERNEL);
496 		if (!dvbdevfops) {
497 			kfree(dvbdev);
498 			*pdvbdev = NULL;
499 			mutex_unlock(&dvbdev_register_lock);
500 			return -ENOMEM;
501 		}
502 
503 		new_node = kzalloc(sizeof(*new_node), GFP_KERNEL);
504 		if (!new_node) {
505 			kfree(dvbdevfops);
506 			kfree(dvbdev);
507 			*pdvbdev = NULL;
508 			mutex_unlock(&dvbdev_register_lock);
509 			return -ENOMEM;
510 		}
511 
512 		new_node->fops = dvbdevfops;
513 		new_node->type = type;
514 		new_node->template = template;
515 		list_add_tail(&new_node->list_head, &dvbdevfops_list);
516 	}
517 
518 	memcpy(dvbdev, template, sizeof(struct dvb_device));
519 	kref_init(&dvbdev->ref);
520 	dvbdev->type = type;
521 	dvbdev->id = id;
522 	dvbdev->adapter = adap;
523 	dvbdev->priv = priv;
524 	dvbdev->fops = dvbdevfops;
525 	init_waitqueue_head(&dvbdev->wait_queue);
526 	dvbdevfops->owner = adap->module;
527 	list_add_tail(&dvbdev->list_head, &adap->device_list);
528 	down_write(&minor_rwsem);
529 #ifdef CONFIG_DVB_DYNAMIC_MINORS
530 	for (minor = 0; minor < MAX_DVB_MINORS; minor++)
531 		if (!dvb_minors[minor])
532 			break;
533 #else
534 	minor = nums2minor(adap->num, type, id);
535 #endif
536 	if (minor >= MAX_DVB_MINORS) {
537 		if (new_node) {
538 			list_del(&new_node->list_head);
539 			kfree(dvbdevfops);
540 			kfree(new_node);
541 		}
542 		list_del(&dvbdev->list_head);
543 		kfree(dvbdev);
544 		*pdvbdev = NULL;
545 		up_write(&minor_rwsem);
546 		mutex_unlock(&dvbdev_register_lock);
547 		return -EINVAL;
548 	}
549 
550 	dvbdev->minor = minor;
551 	dvb_minors[minor] = dvb_device_get(dvbdev);
552 	up_write(&minor_rwsem);
553 	ret = dvb_register_media_device(dvbdev, type, minor, demux_sink_pads);
554 	if (ret) {
555 		pr_err("%s: dvb_register_media_device failed to create the mediagraph\n",
556 		       __func__);
557 		if (new_node) {
558 			list_del(&new_node->list_head);
559 			kfree(dvbdevfops);
560 			kfree(new_node);
561 		}
562 		dvb_media_device_free(dvbdev);
563 		list_del(&dvbdev->list_head);
564 		kfree(dvbdev);
565 		*pdvbdev = NULL;
566 		mutex_unlock(&dvbdev_register_lock);
567 		return ret;
568 	}
569 
570 	clsdev = device_create(dvb_class, adap->device,
571 			       MKDEV(DVB_MAJOR, minor),
572 			       dvbdev, "dvb%d.%s%d", adap->num, dnames[type], id);
573 	if (IS_ERR(clsdev)) {
574 		pr_err("%s: failed to create device dvb%d.%s%d (%ld)\n",
575 		       __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
576 		if (new_node) {
577 			list_del(&new_node->list_head);
578 			kfree(dvbdevfops);
579 			kfree(new_node);
580 		}
581 		dvb_media_device_free(dvbdev);
582 		list_del(&dvbdev->list_head);
583 		kfree(dvbdev);
584 		*pdvbdev = NULL;
585 		mutex_unlock(&dvbdev_register_lock);
586 		return PTR_ERR(clsdev);
587 	}
588 
589 	dprintk("DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
590 		adap->num, dnames[type], id, minor, minor);
591 
592 	mutex_unlock(&dvbdev_register_lock);
593 	return 0;
594 }
595 EXPORT_SYMBOL(dvb_register_device);
596 
597 void dvb_remove_device(struct dvb_device *dvbdev)
598 {
599 	if (!dvbdev)
600 		return;
601 
602 	down_write(&minor_rwsem);
603 	dvb_minors[dvbdev->minor] = NULL;
604 	dvb_device_put(dvbdev);
605 	up_write(&minor_rwsem);
606 
607 	dvb_media_device_free(dvbdev);
608 
609 	device_destroy(dvb_class, MKDEV(DVB_MAJOR, dvbdev->minor));
610 
611 	list_del(&dvbdev->list_head);
612 }
613 EXPORT_SYMBOL(dvb_remove_device);
614 
615 static void dvb_free_device(struct kref *ref)
616 {
617 	struct dvb_device *dvbdev = container_of(ref, struct dvb_device, ref);
618 
619 	kfree(dvbdev);
620 }
621 
622 struct dvb_device *dvb_device_get(struct dvb_device *dvbdev)
623 {
624 	kref_get(&dvbdev->ref);
625 	return dvbdev;
626 }
627 EXPORT_SYMBOL(dvb_device_get);
628 
629 void dvb_device_put(struct dvb_device *dvbdev)
630 {
631 	if (dvbdev)
632 		kref_put(&dvbdev->ref, dvb_free_device);
633 }
634 
635 void dvb_unregister_device(struct dvb_device *dvbdev)
636 {
637 	dvb_remove_device(dvbdev);
638 	dvb_device_put(dvbdev);
639 }
640 EXPORT_SYMBOL(dvb_unregister_device);
641 
642 #ifdef CONFIG_MEDIA_CONTROLLER_DVB
643 
644 static int dvb_create_io_intf_links(struct dvb_adapter *adap,
645 				    struct media_interface *intf,
646 				    char *name)
647 {
648 	struct media_device *mdev = adap->mdev;
649 	struct media_entity *entity;
650 	struct media_link *link;
651 
652 	media_device_for_each_entity(entity, mdev) {
653 		if (entity->function == MEDIA_ENT_F_IO_DTV) {
654 			if (strncmp(entity->name, name, strlen(name)))
655 				continue;
656 			link = media_create_intf_link(entity, intf,
657 						      MEDIA_LNK_FL_ENABLED |
658 						      MEDIA_LNK_FL_IMMUTABLE);
659 			if (!link)
660 				return -ENOMEM;
661 		}
662 	}
663 	return 0;
664 }
665 
666 int dvb_create_media_graph(struct dvb_adapter *adap,
667 			   bool create_rf_connector)
668 {
669 	struct media_device *mdev = adap->mdev;
670 	struct media_entity *entity, *tuner = NULL, *demod = NULL, *conn;
671 	struct media_entity *demux = NULL, *ca = NULL;
672 	struct media_link *link;
673 	struct media_interface *intf;
674 	unsigned int demux_pad = 0;
675 	unsigned int dvr_pad = 0;
676 	unsigned int ntuner = 0, ndemod = 0;
677 	int ret, pad_source, pad_sink;
678 	static const char *connector_name = "Television";
679 
680 	if (!mdev)
681 		return 0;
682 
683 	media_device_for_each_entity(entity, mdev) {
684 		switch (entity->function) {
685 		case MEDIA_ENT_F_TUNER:
686 			tuner = entity;
687 			ntuner++;
688 			break;
689 		case MEDIA_ENT_F_DTV_DEMOD:
690 			demod = entity;
691 			ndemod++;
692 			break;
693 		case MEDIA_ENT_F_TS_DEMUX:
694 			demux = entity;
695 			break;
696 		case MEDIA_ENT_F_DTV_CA:
697 			ca = entity;
698 			break;
699 		}
700 	}
701 
702 	/*
703 	 * Prepare to signalize to media_create_pad_links() that multiple
704 	 * entities of the same type exists and a 1:n or n:1 links need to be
705 	 * created.
706 	 * NOTE: if both tuner and demod have multiple instances, it is up
707 	 * to the caller driver to create such links.
708 	 */
709 	if (ntuner > 1)
710 		tuner = NULL;
711 	if (ndemod > 1)
712 		demod = NULL;
713 
714 	if (create_rf_connector) {
715 		conn = kzalloc(sizeof(*conn), GFP_KERNEL);
716 		if (!conn)
717 			return -ENOMEM;
718 		adap->conn = conn;
719 
720 		adap->conn_pads = kzalloc(sizeof(*adap->conn_pads), GFP_KERNEL);
721 		if (!adap->conn_pads)
722 			return -ENOMEM;
723 
724 		conn->flags = MEDIA_ENT_FL_CONNECTOR;
725 		conn->function = MEDIA_ENT_F_CONN_RF;
726 		conn->name = connector_name;
727 		adap->conn_pads->flags = MEDIA_PAD_FL_SOURCE;
728 
729 		ret = media_entity_pads_init(conn, 1, adap->conn_pads);
730 		if (ret)
731 			return ret;
732 
733 		ret = media_device_register_entity(mdev, conn);
734 		if (ret)
735 			return ret;
736 
737 		if (!ntuner) {
738 			ret = media_create_pad_links(mdev,
739 						     MEDIA_ENT_F_CONN_RF,
740 						     conn, 0,
741 						     MEDIA_ENT_F_DTV_DEMOD,
742 						     demod, 0,
743 						     MEDIA_LNK_FL_ENABLED,
744 						     false);
745 		} else {
746 			pad_sink = media_get_pad_index(tuner, MEDIA_PAD_FL_SINK,
747 						       PAD_SIGNAL_ANALOG);
748 			if (pad_sink < 0)
749 				return -EINVAL;
750 			ret = media_create_pad_links(mdev,
751 						     MEDIA_ENT_F_CONN_RF,
752 						     conn, 0,
753 						     MEDIA_ENT_F_TUNER,
754 						     tuner, pad_sink,
755 						     MEDIA_LNK_FL_ENABLED,
756 						     false);
757 		}
758 		if (ret)
759 			return ret;
760 	}
761 
762 	if (ntuner && ndemod) {
763 		/* NOTE: first found tuner source pad presumed correct */
764 		pad_source = media_get_pad_index(tuner, MEDIA_PAD_FL_SOURCE,
765 						 PAD_SIGNAL_ANALOG);
766 		if (pad_source < 0)
767 			return -EINVAL;
768 		ret = media_create_pad_links(mdev,
769 					     MEDIA_ENT_F_TUNER,
770 					     tuner, pad_source,
771 					     MEDIA_ENT_F_DTV_DEMOD,
772 					     demod, 0, MEDIA_LNK_FL_ENABLED,
773 					     false);
774 		if (ret)
775 			return ret;
776 	}
777 
778 	if (ndemod && demux) {
779 		ret = media_create_pad_links(mdev,
780 					     MEDIA_ENT_F_DTV_DEMOD,
781 					     demod, 1,
782 					     MEDIA_ENT_F_TS_DEMUX,
783 					     demux, 0, MEDIA_LNK_FL_ENABLED,
784 					     false);
785 		if (ret)
786 			return ret;
787 	}
788 	if (demux && ca) {
789 		ret = media_create_pad_link(demux, 1, ca,
790 					    0, MEDIA_LNK_FL_ENABLED);
791 		if (ret)
792 			return ret;
793 	}
794 
795 	/* Create demux links for each ringbuffer/pad */
796 	if (demux) {
797 		media_device_for_each_entity(entity, mdev) {
798 			if (entity->function == MEDIA_ENT_F_IO_DTV) {
799 				if (!strncmp(entity->name, DVR_TSOUT,
800 					     strlen(DVR_TSOUT))) {
801 					ret = media_create_pad_link(demux,
802 								    ++dvr_pad,
803 								    entity, 0, 0);
804 					if (ret)
805 						return ret;
806 				}
807 				if (!strncmp(entity->name, DEMUX_TSOUT,
808 					     strlen(DEMUX_TSOUT))) {
809 					ret = media_create_pad_link(demux,
810 								    ++demux_pad,
811 								    entity, 0, 0);
812 					if (ret)
813 						return ret;
814 				}
815 			}
816 		}
817 	}
818 
819 	/* Create interface links for FE->tuner, DVR->demux and CA->ca */
820 	media_device_for_each_intf(intf, mdev) {
821 		if (intf->type == MEDIA_INTF_T_DVB_CA && ca) {
822 			link = media_create_intf_link(ca, intf,
823 						      MEDIA_LNK_FL_ENABLED |
824 						      MEDIA_LNK_FL_IMMUTABLE);
825 			if (!link)
826 				return -ENOMEM;
827 		}
828 
829 		if (intf->type == MEDIA_INTF_T_DVB_FE && tuner) {
830 			link = media_create_intf_link(tuner, intf,
831 						      MEDIA_LNK_FL_ENABLED |
832 						      MEDIA_LNK_FL_IMMUTABLE);
833 			if (!link)
834 				return -ENOMEM;
835 		}
836 #if 0
837 		/*
838 		 * Indirect link - let's not create yet, as we don't know how
839 		 *		   to handle indirect links, nor if this will
840 		 *		   actually be needed.
841 		 */
842 		if (intf->type == MEDIA_INTF_T_DVB_DVR && demux) {
843 			link = media_create_intf_link(demux, intf,
844 						      MEDIA_LNK_FL_ENABLED |
845 						      MEDIA_LNK_FL_IMMUTABLE);
846 			if (!link)
847 				return -ENOMEM;
848 		}
849 #endif
850 		if (intf->type == MEDIA_INTF_T_DVB_DVR) {
851 			ret = dvb_create_io_intf_links(adap, intf, DVR_TSOUT);
852 			if (ret)
853 				return ret;
854 		}
855 		if (intf->type == MEDIA_INTF_T_DVB_DEMUX) {
856 			ret = dvb_create_io_intf_links(adap, intf, DEMUX_TSOUT);
857 			if (ret)
858 				return ret;
859 		}
860 	}
861 	return 0;
862 }
863 EXPORT_SYMBOL_GPL(dvb_create_media_graph);
864 #endif
865 
866 static int dvbdev_check_free_adapter_num(int num)
867 {
868 	struct list_head *entry;
869 
870 	list_for_each(entry, &dvb_adapter_list) {
871 		struct dvb_adapter *adap;
872 
873 		adap = list_entry(entry, struct dvb_adapter, list_head);
874 		if (adap->num == num)
875 			return 0;
876 	}
877 	return 1;
878 }
879 
880 static int dvbdev_get_free_adapter_num(void)
881 {
882 	int num = 0;
883 
884 	while (num < DVB_MAX_ADAPTERS) {
885 		if (dvbdev_check_free_adapter_num(num))
886 			return num;
887 		num++;
888 	}
889 
890 	return -ENFILE;
891 }
892 
893 int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
894 			 struct module *module, struct device *device,
895 			 short *adapter_nums)
896 {
897 	int i, num;
898 
899 	mutex_lock(&dvbdev_register_lock);
900 
901 	for (i = 0; i < DVB_MAX_ADAPTERS; ++i) {
902 		num = adapter_nums[i];
903 		if (num >= 0  &&  num < DVB_MAX_ADAPTERS) {
904 		/* use the one the driver asked for */
905 			if (dvbdev_check_free_adapter_num(num))
906 				break;
907 		} else {
908 			num = dvbdev_get_free_adapter_num();
909 			break;
910 		}
911 		num = -1;
912 	}
913 
914 	if (num < 0) {
915 		mutex_unlock(&dvbdev_register_lock);
916 		return -ENFILE;
917 	}
918 
919 	memset(adap, 0, sizeof(struct dvb_adapter));
920 	INIT_LIST_HEAD(&adap->device_list);
921 
922 	pr_info("DVB: registering new adapter (%s)\n", name);
923 
924 	adap->num = num;
925 	adap->name = name;
926 	adap->module = module;
927 	adap->device = device;
928 	adap->mfe_shared = 0;
929 	adap->mfe_dvbdev = NULL;
930 	mutex_init(&adap->mfe_lock);
931 
932 #ifdef CONFIG_MEDIA_CONTROLLER_DVB
933 	mutex_init(&adap->mdev_lock);
934 #endif
935 
936 	list_add_tail(&adap->list_head, &dvb_adapter_list);
937 
938 	mutex_unlock(&dvbdev_register_lock);
939 
940 	return num;
941 }
942 EXPORT_SYMBOL(dvb_register_adapter);
943 
944 int dvb_unregister_adapter(struct dvb_adapter *adap)
945 {
946 	mutex_lock(&dvbdev_register_lock);
947 	list_del(&adap->list_head);
948 	mutex_unlock(&dvbdev_register_lock);
949 	return 0;
950 }
951 EXPORT_SYMBOL(dvb_unregister_adapter);
952 
953 /*
954  * if the miracle happens and "generic_usercopy()" is included into
955  * the kernel, then this can vanish. please don't make the mistake and
956  * define this as video_usercopy(). this will introduce a dependency
957  * to the v4l "videodev.o" module, which is unnecessary for some
958  * cards (ie. the budget dvb-cards don't need the v4l module...)
959  */
960 int dvb_usercopy(struct file *file,
961 		 unsigned int cmd, unsigned long arg,
962 		 int (*func)(struct file *file,
963 			     unsigned int cmd, void *arg))
964 {
965 	char    sbuf[128] = {};
966 	void    *mbuf = NULL;
967 	void    *parg = NULL;
968 	int     err  = -EINVAL;
969 
970 	/*  Copy arguments into temp kernel buffer  */
971 	switch (_IOC_DIR(cmd)) {
972 	case _IOC_NONE:
973 		/*
974 		 * For this command, the pointer is actually an integer
975 		 * argument.
976 		 */
977 		parg = (void *)arg;
978 		break;
979 	case _IOC_READ: /* some v4l ioctls are marked wrong ... */
980 	case _IOC_WRITE:
981 	case (_IOC_WRITE | _IOC_READ):
982 		if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
983 			parg = sbuf;
984 		} else {
985 			/* too big to allocate from stack */
986 			mbuf = kmalloc(_IOC_SIZE(cmd), GFP_KERNEL);
987 			if (!mbuf)
988 				return -ENOMEM;
989 			parg = mbuf;
990 		}
991 
992 		err = -EFAULT;
993 		if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
994 			goto out;
995 		break;
996 	}
997 
998 	/* call driver */
999 	err = func(file, cmd, parg);
1000 	if (err == -ENOIOCTLCMD)
1001 		err = -ENOTTY;
1002 
1003 	if (err < 0)
1004 		goto out;
1005 
1006 	/*  Copy results into user buffer  */
1007 	switch (_IOC_DIR(cmd)) {
1008 	case _IOC_READ:
1009 	case (_IOC_WRITE | _IOC_READ):
1010 		if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
1011 			err = -EFAULT;
1012 		break;
1013 	}
1014 
1015 out:
1016 	kfree(mbuf);
1017 	return err;
1018 }
1019 
1020 #if IS_ENABLED(CONFIG_I2C)
1021 struct i2c_client *dvb_module_probe(const char *module_name,
1022 				    const char *name,
1023 				    struct i2c_adapter *adap,
1024 				    unsigned char addr,
1025 				    void *platform_data)
1026 {
1027 	struct i2c_client *client;
1028 	struct i2c_board_info *board_info;
1029 
1030 	board_info = kzalloc(sizeof(*board_info), GFP_KERNEL);
1031 	if (!board_info)
1032 		return NULL;
1033 
1034 	if (name)
1035 		strscpy(board_info->type, name, I2C_NAME_SIZE);
1036 	else
1037 		strscpy(board_info->type, module_name, I2C_NAME_SIZE);
1038 
1039 	board_info->addr = addr;
1040 	board_info->platform_data = platform_data;
1041 	request_module(module_name);
1042 	client = i2c_new_client_device(adap, board_info);
1043 	if (!i2c_client_has_driver(client)) {
1044 		kfree(board_info);
1045 		return NULL;
1046 	}
1047 
1048 	if (!try_module_get(client->dev.driver->owner)) {
1049 		i2c_unregister_device(client);
1050 		client = NULL;
1051 	}
1052 
1053 	kfree(board_info);
1054 	return client;
1055 }
1056 EXPORT_SYMBOL_GPL(dvb_module_probe);
1057 
1058 void dvb_module_release(struct i2c_client *client)
1059 {
1060 	if (!client)
1061 		return;
1062 
1063 	module_put(client->dev.driver->owner);
1064 	i2c_unregister_device(client);
1065 }
1066 EXPORT_SYMBOL_GPL(dvb_module_release);
1067 #endif
1068 
1069 static int dvb_uevent(const struct device *dev, struct kobj_uevent_env *env)
1070 {
1071 	const struct dvb_device *dvbdev = dev_get_drvdata(dev);
1072 
1073 	add_uevent_var(env, "DVB_ADAPTER_NUM=%d", dvbdev->adapter->num);
1074 	add_uevent_var(env, "DVB_DEVICE_TYPE=%s", dnames[dvbdev->type]);
1075 	add_uevent_var(env, "DVB_DEVICE_NUM=%d", dvbdev->id);
1076 	return 0;
1077 }
1078 
1079 static char *dvb_devnode(const struct device *dev, umode_t *mode)
1080 {
1081 	const struct dvb_device *dvbdev = dev_get_drvdata(dev);
1082 
1083 	return kasprintf(GFP_KERNEL, "dvb/adapter%d/%s%d",
1084 		dvbdev->adapter->num, dnames[dvbdev->type], dvbdev->id);
1085 }
1086 
1087 static int __init init_dvbdev(void)
1088 {
1089 	int retval;
1090 	dev_t dev = MKDEV(DVB_MAJOR, 0);
1091 
1092 	retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB");
1093 	if (retval != 0) {
1094 		pr_err("dvb-core: unable to get major %d\n", DVB_MAJOR);
1095 		return retval;
1096 	}
1097 
1098 	cdev_init(&dvb_device_cdev, &dvb_device_fops);
1099 	retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS);
1100 	if (retval != 0) {
1101 		pr_err("dvb-core: unable register character device\n");
1102 		goto error;
1103 	}
1104 
1105 	dvb_class = class_create("dvb");
1106 	if (IS_ERR(dvb_class)) {
1107 		retval = PTR_ERR(dvb_class);
1108 		goto error;
1109 	}
1110 	dvb_class->dev_uevent = dvb_uevent;
1111 	dvb_class->devnode = dvb_devnode;
1112 	return 0;
1113 
1114 error:
1115 	cdev_del(&dvb_device_cdev);
1116 	unregister_chrdev_region(dev, MAX_DVB_MINORS);
1117 	return retval;
1118 }
1119 
1120 static void __exit exit_dvbdev(void)
1121 {
1122 	struct dvbdevfops_node *node, *next;
1123 
1124 	class_destroy(dvb_class);
1125 	cdev_del(&dvb_device_cdev);
1126 	unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
1127 
1128 	list_for_each_entry_safe(node, next, &dvbdevfops_list, list_head) {
1129 		list_del(&node->list_head);
1130 		kfree(node->fops);
1131 		kfree(node);
1132 	}
1133 }
1134 
1135 subsys_initcall(init_dvbdev);
1136 module_exit(exit_dvbdev);
1137 
1138 MODULE_DESCRIPTION("DVB Core Driver");
1139 MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
1140 MODULE_LICENSE("GPL");
1141