xref: /openbmc/linux/drivers/media/dvb-core/dvbdev.c (revision 60eb644b)
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 
90 	mutex_lock(&dvbdev_mutex);
91 	down_read(&minor_rwsem);
92 	dvbdev = dvb_minors[iminor(inode)];
93 
94 	if (dvbdev && dvbdev->fops) {
95 		int err = 0;
96 		const struct file_operations *new_fops;
97 
98 		new_fops = fops_get(dvbdev->fops);
99 		if (!new_fops)
100 			goto fail;
101 		file->private_data = dvb_device_get(dvbdev);
102 		replace_fops(file, new_fops);
103 		if (file->f_op->open)
104 			err = file->f_op->open(inode, file);
105 		up_read(&minor_rwsem);
106 		mutex_unlock(&dvbdev_mutex);
107 		return err;
108 	}
109 fail:
110 	up_read(&minor_rwsem);
111 	mutex_unlock(&dvbdev_mutex);
112 	return -ENODEV;
113 }
114 
115 
116 static const struct file_operations dvb_device_fops =
117 {
118 	.owner =	THIS_MODULE,
119 	.open =		dvb_device_open,
120 	.llseek =	noop_llseek,
121 };
122 
123 static struct cdev dvb_device_cdev;
124 
125 int dvb_generic_open(struct inode *inode, struct file *file)
126 {
127 	struct dvb_device *dvbdev = file->private_data;
128 
129 	if (!dvbdev)
130 		return -ENODEV;
131 
132 	if (!dvbdev->users)
133 		return -EBUSY;
134 
135 	if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
136 		if (!dvbdev->readers)
137 			return -EBUSY;
138 		dvbdev->readers--;
139 	} else {
140 		if (!dvbdev->writers)
141 			return -EBUSY;
142 		dvbdev->writers--;
143 	}
144 
145 	dvbdev->users--;
146 	return 0;
147 }
148 EXPORT_SYMBOL(dvb_generic_open);
149 
150 
151 int dvb_generic_release(struct inode *inode, struct file *file)
152 {
153 	struct dvb_device *dvbdev = file->private_data;
154 
155 	if (!dvbdev)
156 		return -ENODEV;
157 
158 	if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
159 		dvbdev->readers++;
160 	} else {
161 		dvbdev->writers++;
162 	}
163 
164 	dvbdev->users++;
165 
166 	dvb_device_put(dvbdev);
167 
168 	return 0;
169 }
170 EXPORT_SYMBOL(dvb_generic_release);
171 
172 
173 long dvb_generic_ioctl(struct file *file,
174 		       unsigned int cmd, unsigned long arg)
175 {
176 	struct dvb_device *dvbdev = file->private_data;
177 
178 	if (!dvbdev)
179 		return -ENODEV;
180 
181 	if (!dvbdev->kernel_ioctl)
182 		return -EINVAL;
183 
184 	return dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
185 }
186 EXPORT_SYMBOL(dvb_generic_ioctl);
187 
188 
189 static int dvbdev_get_free_id (struct dvb_adapter *adap, int type)
190 {
191 	u32 id = 0;
192 
193 	while (id < DVB_MAX_IDS) {
194 		struct dvb_device *dev;
195 		list_for_each_entry(dev, &adap->device_list, list_head)
196 			if (dev->type == type && dev->id == id)
197 				goto skip;
198 		return id;
199 skip:
200 		id++;
201 	}
202 	return -ENFILE;
203 }
204 
205 static void dvb_media_device_free(struct dvb_device *dvbdev)
206 {
207 #if defined(CONFIG_MEDIA_CONTROLLER_DVB)
208 	if (dvbdev->entity) {
209 		media_device_unregister_entity(dvbdev->entity);
210 		kfree(dvbdev->entity);
211 		kfree(dvbdev->pads);
212 		dvbdev->entity = NULL;
213 		dvbdev->pads = NULL;
214 	}
215 
216 	if (dvbdev->tsout_entity) {
217 		int i;
218 
219 		for (i = 0; i < dvbdev->tsout_num_entities; i++) {
220 			media_device_unregister_entity(&dvbdev->tsout_entity[i]);
221 			kfree(dvbdev->tsout_entity[i].name);
222 		}
223 		kfree(dvbdev->tsout_entity);
224 		kfree(dvbdev->tsout_pads);
225 		dvbdev->tsout_entity = NULL;
226 		dvbdev->tsout_pads = NULL;
227 
228 		dvbdev->tsout_num_entities = 0;
229 	}
230 
231 	if (dvbdev->intf_devnode) {
232 		media_devnode_remove(dvbdev->intf_devnode);
233 		dvbdev->intf_devnode = NULL;
234 	}
235 
236 	if (dvbdev->adapter->conn) {
237 		media_device_unregister_entity(dvbdev->adapter->conn);
238 		kfree(dvbdev->adapter->conn);
239 		dvbdev->adapter->conn = NULL;
240 		kfree(dvbdev->adapter->conn_pads);
241 		dvbdev->adapter->conn_pads = NULL;
242 	}
243 #endif
244 }
245 
246 #if defined(CONFIG_MEDIA_CONTROLLER_DVB)
247 static int dvb_create_tsout_entity(struct dvb_device *dvbdev,
248 				    const char *name, int npads)
249 {
250 	int i;
251 
252 	dvbdev->tsout_pads = kcalloc(npads, sizeof(*dvbdev->tsout_pads),
253 				     GFP_KERNEL);
254 	if (!dvbdev->tsout_pads)
255 		return -ENOMEM;
256 
257 	dvbdev->tsout_entity = kcalloc(npads, sizeof(*dvbdev->tsout_entity),
258 				       GFP_KERNEL);
259 	if (!dvbdev->tsout_entity)
260 		return -ENOMEM;
261 
262 	dvbdev->tsout_num_entities = npads;
263 
264 	for (i = 0; i < npads; i++) {
265 		struct media_pad *pads = &dvbdev->tsout_pads[i];
266 		struct media_entity *entity = &dvbdev->tsout_entity[i];
267 		int ret;
268 
269 		entity->name = kasprintf(GFP_KERNEL, "%s #%d", name, i);
270 		if (!entity->name)
271 			return -ENOMEM;
272 
273 		entity->function = MEDIA_ENT_F_IO_DTV;
274 		pads->flags = MEDIA_PAD_FL_SINK;
275 
276 		ret = media_entity_pads_init(entity, 1, pads);
277 		if (ret < 0)
278 			return ret;
279 
280 		ret = media_device_register_entity(dvbdev->adapter->mdev,
281 						   entity);
282 		if (ret < 0)
283 			return ret;
284 	}
285 	return 0;
286 }
287 
288 #define DEMUX_TSOUT	"demux-tsout"
289 #define DVR_TSOUT	"dvr-tsout"
290 
291 static int dvb_create_media_entity(struct dvb_device *dvbdev,
292 				   int type, int demux_sink_pads)
293 {
294 	int i, ret, npads;
295 
296 	switch (type) {
297 	case DVB_DEVICE_FRONTEND:
298 		npads = 2;
299 		break;
300 	case DVB_DEVICE_DVR:
301 		ret = dvb_create_tsout_entity(dvbdev, DVR_TSOUT,
302 					      demux_sink_pads);
303 		return ret;
304 	case DVB_DEVICE_DEMUX:
305 		npads = 1 + demux_sink_pads;
306 		ret = dvb_create_tsout_entity(dvbdev, DEMUX_TSOUT,
307 					      demux_sink_pads);
308 		if (ret < 0)
309 			return ret;
310 		break;
311 	case DVB_DEVICE_CA:
312 		npads = 2;
313 		break;
314 	case DVB_DEVICE_NET:
315 		/*
316 		 * We should be creating entities for the MPE/ULE
317 		 * decapsulation hardware (or software implementation).
318 		 *
319 		 * However, the number of for the MPE/ULE decaps may not be
320 		 * fixed. As we don't have yet dynamic support for PADs at
321 		 * the Media Controller, let's not create the decap
322 		 * entities yet.
323 		 */
324 		return 0;
325 	default:
326 		return 0;
327 	}
328 
329 	dvbdev->entity = kzalloc(sizeof(*dvbdev->entity), GFP_KERNEL);
330 	if (!dvbdev->entity)
331 		return -ENOMEM;
332 
333 	dvbdev->entity->name = dvbdev->name;
334 
335 	if (npads) {
336 		dvbdev->pads = kcalloc(npads, sizeof(*dvbdev->pads),
337 				       GFP_KERNEL);
338 		if (!dvbdev->pads) {
339 			kfree(dvbdev->entity);
340 			dvbdev->entity = NULL;
341 			return -ENOMEM;
342 		}
343 	}
344 
345 	switch (type) {
346 	case DVB_DEVICE_FRONTEND:
347 		dvbdev->entity->function = MEDIA_ENT_F_DTV_DEMOD;
348 		dvbdev->pads[0].flags = MEDIA_PAD_FL_SINK;
349 		dvbdev->pads[1].flags = MEDIA_PAD_FL_SOURCE;
350 		break;
351 	case DVB_DEVICE_DEMUX:
352 		dvbdev->entity->function = MEDIA_ENT_F_TS_DEMUX;
353 		dvbdev->pads[0].flags = MEDIA_PAD_FL_SINK;
354 		for (i = 1; i < npads; i++)
355 			dvbdev->pads[i].flags = MEDIA_PAD_FL_SOURCE;
356 		break;
357 	case DVB_DEVICE_CA:
358 		dvbdev->entity->function = MEDIA_ENT_F_DTV_CA;
359 		dvbdev->pads[0].flags = MEDIA_PAD_FL_SINK;
360 		dvbdev->pads[1].flags = MEDIA_PAD_FL_SOURCE;
361 		break;
362 	default:
363 		/* Should never happen, as the first switch prevents it */
364 		kfree(dvbdev->entity);
365 		kfree(dvbdev->pads);
366 		dvbdev->entity = NULL;
367 		dvbdev->pads = NULL;
368 		return 0;
369 	}
370 
371 	if (npads) {
372 		ret = media_entity_pads_init(dvbdev->entity, npads, dvbdev->pads);
373 		if (ret)
374 			return ret;
375 	}
376 	ret = media_device_register_entity(dvbdev->adapter->mdev,
377 					   dvbdev->entity);
378 	if (ret)
379 		return ret;
380 
381 	pr_info("%s: media entity '%s' registered.\n",
382 		__func__, dvbdev->entity->name);
383 
384 	return 0;
385 }
386 #endif
387 
388 static int dvb_register_media_device(struct dvb_device *dvbdev,
389 				     int type, int minor,
390 				     unsigned demux_sink_pads)
391 {
392 #if defined(CONFIG_MEDIA_CONTROLLER_DVB)
393 	struct media_link *link;
394 	u32 intf_type;
395 	int ret;
396 
397 	if (!dvbdev->adapter->mdev)
398 		return 0;
399 
400 	ret = dvb_create_media_entity(dvbdev, type, demux_sink_pads);
401 	if (ret)
402 		return ret;
403 
404 	switch (type) {
405 	case DVB_DEVICE_FRONTEND:
406 		intf_type = MEDIA_INTF_T_DVB_FE;
407 		break;
408 	case DVB_DEVICE_DEMUX:
409 		intf_type = MEDIA_INTF_T_DVB_DEMUX;
410 		break;
411 	case DVB_DEVICE_DVR:
412 		intf_type = MEDIA_INTF_T_DVB_DVR;
413 		break;
414 	case DVB_DEVICE_CA:
415 		intf_type = MEDIA_INTF_T_DVB_CA;
416 		break;
417 	case DVB_DEVICE_NET:
418 		intf_type = MEDIA_INTF_T_DVB_NET;
419 		break;
420 	default:
421 		return 0;
422 	}
423 
424 	dvbdev->intf_devnode = media_devnode_create(dvbdev->adapter->mdev,
425 						    intf_type, 0,
426 						    DVB_MAJOR, minor);
427 
428 	if (!dvbdev->intf_devnode)
429 		return -ENOMEM;
430 
431 	/*
432 	 * Create the "obvious" link, e. g. the ones that represent
433 	 * a direct association between an interface and an entity.
434 	 * Other links should be created elsewhere, like:
435 	 *		DVB FE intf    -> tuner
436 	 *		DVB demux intf -> dvr
437 	 */
438 
439 	if (!dvbdev->entity)
440 		return 0;
441 
442 	link = media_create_intf_link(dvbdev->entity,
443 				      &dvbdev->intf_devnode->intf,
444 				      MEDIA_LNK_FL_ENABLED |
445 				      MEDIA_LNK_FL_IMMUTABLE);
446 	if (!link)
447 		return -ENOMEM;
448 #endif
449 	return 0;
450 }
451 
452 int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
453 			const struct dvb_device *template, void *priv,
454 			enum dvb_device_type type, int demux_sink_pads)
455 {
456 	struct dvb_device *dvbdev;
457 	struct file_operations *dvbdevfops = NULL;
458 	struct dvbdevfops_node *node = NULL, *new_node = NULL;
459 	struct device *clsdev;
460 	int minor;
461 	int id, ret;
462 
463 	mutex_lock(&dvbdev_register_lock);
464 
465 	if ((id = dvbdev_get_free_id (adap, type)) < 0) {
466 		mutex_unlock(&dvbdev_register_lock);
467 		*pdvbdev = NULL;
468 		pr_err("%s: couldn't find free device id\n", __func__);
469 		return -ENFILE;
470 	}
471 
472 	*pdvbdev = dvbdev = kzalloc(sizeof(*dvbdev), GFP_KERNEL);
473 	if (!dvbdev){
474 		mutex_unlock(&dvbdev_register_lock);
475 		return -ENOMEM;
476 	}
477 
478 	/*
479 	 * When a device of the same type is probe()d more than once,
480 	 * the first allocated fops are used. This prevents memory leaks
481 	 * that can occur when the same device is probe()d repeatedly.
482 	 */
483 	list_for_each_entry(node, &dvbdevfops_list, list_head) {
484 		if (node->fops->owner == adap->module &&
485 				node->type == type &&
486 				node->template == template) {
487 			dvbdevfops = node->fops;
488 			break;
489 		}
490 	}
491 
492 	if (dvbdevfops == NULL) {
493 		dvbdevfops = kmemdup(template->fops, sizeof(*dvbdevfops), GFP_KERNEL);
494 		if (!dvbdevfops) {
495 			kfree(dvbdev);
496 			mutex_unlock(&dvbdev_register_lock);
497 			return -ENOMEM;
498 		}
499 
500 		new_node = kzalloc(sizeof(struct dvbdevfops_node), GFP_KERNEL);
501 		if (!new_node) {
502 			kfree(dvbdevfops);
503 			kfree(dvbdev);
504 			mutex_unlock(&dvbdev_register_lock);
505 			return -ENOMEM;
506 		}
507 
508 		new_node->fops = dvbdevfops;
509 		new_node->type = type;
510 		new_node->template = template;
511 		list_add_tail (&new_node->list_head, &dvbdevfops_list);
512 	}
513 
514 	memcpy(dvbdev, template, sizeof(struct dvb_device));
515 	kref_init(&dvbdev->ref);
516 	dvbdev->type = type;
517 	dvbdev->id = id;
518 	dvbdev->adapter = adap;
519 	dvbdev->priv = priv;
520 	dvbdev->fops = dvbdevfops;
521 	init_waitqueue_head (&dvbdev->wait_queue);
522 	dvbdevfops->owner = adap->module;
523 	list_add_tail (&dvbdev->list_head, &adap->device_list);
524 	down_write(&minor_rwsem);
525 #ifdef CONFIG_DVB_DYNAMIC_MINORS
526 	for (minor = 0; minor < MAX_DVB_MINORS; minor++)
527 		if (dvb_minors[minor] == NULL)
528 			break;
529 	if (minor == MAX_DVB_MINORS) {
530 		if (new_node) {
531 			list_del (&new_node->list_head);
532 			kfree(dvbdevfops);
533 			kfree(new_node);
534 		}
535 		list_del (&dvbdev->list_head);
536 		kfree(dvbdev);
537 		up_write(&minor_rwsem);
538 		mutex_unlock(&dvbdev_register_lock);
539 		return -EINVAL;
540 	}
541 #else
542 	minor = nums2minor(adap->num, type, id);
543 #endif
544 	dvbdev->minor = minor;
545 	dvb_minors[minor] = dvb_device_get(dvbdev);
546 	up_write(&minor_rwsem);
547 	ret = dvb_register_media_device(dvbdev, type, minor, demux_sink_pads);
548 	if (ret) {
549 		pr_err("%s: dvb_register_media_device failed to create the mediagraph\n",
550 		      __func__);
551 		if (new_node) {
552 			list_del (&new_node->list_head);
553 			kfree(dvbdevfops);
554 			kfree(new_node);
555 		}
556 		dvb_media_device_free(dvbdev);
557 		list_del (&dvbdev->list_head);
558 		kfree(dvbdev);
559 		mutex_unlock(&dvbdev_register_lock);
560 		return ret;
561 	}
562 
563 	clsdev = device_create(dvb_class, adap->device,
564 			       MKDEV(DVB_MAJOR, minor),
565 			       dvbdev, "dvb%d.%s%d", adap->num, dnames[type], id);
566 	if (IS_ERR(clsdev)) {
567 		pr_err("%s: failed to create device dvb%d.%s%d (%ld)\n",
568 		       __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
569 		if (new_node) {
570 			list_del (&new_node->list_head);
571 			kfree(dvbdevfops);
572 			kfree(new_node);
573 		}
574 		dvb_media_device_free(dvbdev);
575 		list_del (&dvbdev->list_head);
576 		kfree(dvbdev);
577 		mutex_unlock(&dvbdev_register_lock);
578 		return PTR_ERR(clsdev);
579 	}
580 
581 	dprintk("DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
582 		adap->num, dnames[type], id, minor, minor);
583 
584 	mutex_unlock(&dvbdev_register_lock);
585 	return 0;
586 }
587 EXPORT_SYMBOL(dvb_register_device);
588 
589 
590 void dvb_remove_device(struct dvb_device *dvbdev)
591 {
592 	if (!dvbdev)
593 		return;
594 
595 	down_write(&minor_rwsem);
596 	dvb_minors[dvbdev->minor] = NULL;
597 	dvb_device_put(dvbdev);
598 	up_write(&minor_rwsem);
599 
600 	dvb_media_device_free(dvbdev);
601 
602 	device_destroy(dvb_class, MKDEV(DVB_MAJOR, dvbdev->minor));
603 
604 	list_del (&dvbdev->list_head);
605 }
606 EXPORT_SYMBOL(dvb_remove_device);
607 
608 
609 static void dvb_free_device(struct kref *ref)
610 {
611 	struct dvb_device *dvbdev = container_of(ref, struct dvb_device, ref);
612 
613 	kfree (dvbdev);
614 }
615 
616 
617 struct dvb_device *dvb_device_get(struct dvb_device *dvbdev)
618 {
619 	kref_get(&dvbdev->ref);
620 	return dvbdev;
621 }
622 EXPORT_SYMBOL(dvb_device_get);
623 
624 
625 void dvb_device_put(struct dvb_device *dvbdev)
626 {
627 	if (dvbdev)
628 		kref_put(&dvbdev->ref, dvb_free_device);
629 }
630 
631 
632 void dvb_unregister_device(struct dvb_device *dvbdev)
633 {
634 	dvb_remove_device(dvbdev);
635 	dvb_device_put(dvbdev);
636 }
637 EXPORT_SYMBOL(dvb_unregister_device);
638 
639 
640 #ifdef CONFIG_MEDIA_CONTROLLER_DVB
641 
642 static int dvb_create_io_intf_links(struct dvb_adapter *adap,
643 				    struct media_interface *intf,
644 				    char *name)
645 {
646 	struct media_device *mdev = adap->mdev;
647 	struct media_entity *entity;
648 	struct media_link *link;
649 
650 	media_device_for_each_entity(entity, mdev) {
651 		if (entity->function == MEDIA_ENT_F_IO_DTV) {
652 			if (strncmp(entity->name, name, strlen(name)))
653 				continue;
654 			link = media_create_intf_link(entity, intf,
655 						      MEDIA_LNK_FL_ENABLED |
656 						      MEDIA_LNK_FL_IMMUTABLE);
657 			if (!link)
658 				return -ENOMEM;
659 		}
660 	}
661 	return 0;
662 }
663 
664 int dvb_create_media_graph(struct dvb_adapter *adap,
665 			   bool create_rf_connector)
666 {
667 	struct media_device *mdev = adap->mdev;
668 	struct media_entity *entity, *tuner = NULL, *demod = NULL, *conn;
669 	struct media_entity *demux = NULL, *ca = NULL;
670 	struct media_link *link;
671 	struct media_interface *intf;
672 	unsigned demux_pad = 0;
673 	unsigned dvr_pad = 0;
674 	unsigned ntuner = 0, ndemod = 0;
675 	int ret, pad_source, pad_sink;
676 	static const char *connector_name = "Television";
677 
678 	if (!mdev)
679 		return 0;
680 
681 	media_device_for_each_entity(entity, mdev) {
682 		switch (entity->function) {
683 		case MEDIA_ENT_F_TUNER:
684 			tuner = entity;
685 			ntuner++;
686 			break;
687 		case MEDIA_ENT_F_DTV_DEMOD:
688 			demod = entity;
689 			ndemod++;
690 			break;
691 		case MEDIA_ENT_F_TS_DEMUX:
692 			demux = entity;
693 			break;
694 		case MEDIA_ENT_F_DTV_CA:
695 			ca = entity;
696 			break;
697 		}
698 	}
699 
700 	/*
701 	 * Prepare to signalize to media_create_pad_links() that multiple
702 	 * entities of the same type exists and a 1:n or n:1 links need to be
703 	 * created.
704 	 * NOTE: if both tuner and demod have multiple instances, it is up
705 	 * to the caller driver to create such links.
706 	 */
707 	if (ntuner > 1)
708 		tuner = NULL;
709 	if (ndemod > 1)
710 		demod = NULL;
711 
712 	if (create_rf_connector) {
713 		conn = kzalloc(sizeof(*conn), GFP_KERNEL);
714 		if (!conn)
715 			return -ENOMEM;
716 		adap->conn = conn;
717 
718 		adap->conn_pads = kzalloc(sizeof(*adap->conn_pads), GFP_KERNEL);
719 		if (!adap->conn_pads)
720 			return -ENOMEM;
721 
722 		conn->flags = MEDIA_ENT_FL_CONNECTOR;
723 		conn->function = MEDIA_ENT_F_CONN_RF;
724 		conn->name = connector_name;
725 		adap->conn_pads->flags = MEDIA_PAD_FL_SOURCE;
726 
727 		ret = media_entity_pads_init(conn, 1, adap->conn_pads);
728 		if (ret)
729 			return ret;
730 
731 		ret = media_device_register_entity(mdev, conn);
732 		if (ret)
733 			return ret;
734 
735 		if (!ntuner) {
736 			ret = media_create_pad_links(mdev,
737 						     MEDIA_ENT_F_CONN_RF,
738 						     conn, 0,
739 						     MEDIA_ENT_F_DTV_DEMOD,
740 						     demod, 0,
741 						     MEDIA_LNK_FL_ENABLED,
742 						     false);
743 		} else {
744 			pad_sink = media_get_pad_index(tuner, true,
745 						       PAD_SIGNAL_ANALOG);
746 			if (pad_sink < 0)
747 				return -EINVAL;
748 			ret = media_create_pad_links(mdev,
749 						     MEDIA_ENT_F_CONN_RF,
750 						     conn, 0,
751 						     MEDIA_ENT_F_TUNER,
752 						     tuner, pad_sink,
753 						     MEDIA_LNK_FL_ENABLED,
754 						     false);
755 		}
756 		if (ret)
757 			return ret;
758 	}
759 
760 	if (ntuner && ndemod) {
761 		/* NOTE: first found tuner source pad presumed correct */
762 		pad_source = media_get_pad_index(tuner, false,
763 						 PAD_SIGNAL_ANALOG);
764 		if (pad_source < 0)
765 			return -EINVAL;
766 		ret = media_create_pad_links(mdev,
767 					     MEDIA_ENT_F_TUNER,
768 					     tuner, pad_source,
769 					     MEDIA_ENT_F_DTV_DEMOD,
770 					     demod, 0, MEDIA_LNK_FL_ENABLED,
771 					     false);
772 		if (ret)
773 			return ret;
774 	}
775 
776 	if (ndemod && demux) {
777 		ret = media_create_pad_links(mdev,
778 					     MEDIA_ENT_F_DTV_DEMOD,
779 					     demod, 1,
780 					     MEDIA_ENT_F_TS_DEMUX,
781 					     demux, 0, MEDIA_LNK_FL_ENABLED,
782 					     false);
783 		if (ret)
784 			return ret;
785 	}
786 	if (demux && ca) {
787 		ret = media_create_pad_link(demux, 1, ca,
788 					    0, MEDIA_LNK_FL_ENABLED);
789 		if (ret)
790 			return ret;
791 	}
792 
793 	/* Create demux links for each ringbuffer/pad */
794 	if (demux) {
795 		media_device_for_each_entity(entity, mdev) {
796 			if (entity->function == MEDIA_ENT_F_IO_DTV) {
797 				if (!strncmp(entity->name, DVR_TSOUT,
798 				    strlen(DVR_TSOUT))) {
799 					ret = media_create_pad_link(demux,
800 								++dvr_pad,
801 							    entity, 0, 0);
802 					if (ret)
803 						return ret;
804 				}
805 				if (!strncmp(entity->name, DEMUX_TSOUT,
806 				    strlen(DEMUX_TSOUT))) {
807 					ret = media_create_pad_link(demux,
808 							      ++demux_pad,
809 							    entity, 0, 0);
810 					if (ret)
811 						return ret;
812 				}
813 			}
814 		}
815 	}
816 
817 	/* Create interface links for FE->tuner, DVR->demux and CA->ca */
818 	media_device_for_each_intf(intf, mdev) {
819 		if (intf->type == MEDIA_INTF_T_DVB_CA && ca) {
820 			link = media_create_intf_link(ca, intf,
821 						      MEDIA_LNK_FL_ENABLED |
822 						      MEDIA_LNK_FL_IMMUTABLE);
823 			if (!link)
824 				return -ENOMEM;
825 		}
826 
827 		if (intf->type == MEDIA_INTF_T_DVB_FE && tuner) {
828 			link = media_create_intf_link(tuner, intf,
829 						      MEDIA_LNK_FL_ENABLED |
830 						      MEDIA_LNK_FL_IMMUTABLE);
831 			if (!link)
832 				return -ENOMEM;
833 		}
834 #if 0
835 		/*
836 		 * Indirect link - let's not create yet, as we don't know how
837 		 *		   to handle indirect links, nor if this will
838 		 *		   actually be needed.
839 		 */
840 		if (intf->type == MEDIA_INTF_T_DVB_DVR && demux) {
841 			link = media_create_intf_link(demux, intf,
842 						      MEDIA_LNK_FL_ENABLED |
843 						      MEDIA_LNK_FL_IMMUTABLE);
844 			if (!link)
845 				return -ENOMEM;
846 		}
847 #endif
848 		if (intf->type == MEDIA_INTF_T_DVB_DVR) {
849 			ret = dvb_create_io_intf_links(adap, intf, DVR_TSOUT);
850 			if (ret)
851 				return ret;
852 		}
853 		if (intf->type == MEDIA_INTF_T_DVB_DEMUX) {
854 			ret = dvb_create_io_intf_links(adap, intf, DEMUX_TSOUT);
855 			if (ret)
856 				return ret;
857 		}
858 	}
859 	return 0;
860 }
861 EXPORT_SYMBOL_GPL(dvb_create_media_graph);
862 #endif
863 
864 static int dvbdev_check_free_adapter_num(int num)
865 {
866 	struct list_head *entry;
867 	list_for_each(entry, &dvb_adapter_list) {
868 		struct dvb_adapter *adap;
869 		adap = list_entry(entry, struct dvb_adapter, list_head);
870 		if (adap->num == num)
871 			return 0;
872 	}
873 	return 1;
874 }
875 
876 static int dvbdev_get_free_adapter_num (void)
877 {
878 	int num = 0;
879 
880 	while (num < DVB_MAX_ADAPTERS) {
881 		if (dvbdev_check_free_adapter_num(num))
882 			return num;
883 		num++;
884 	}
885 
886 	return -ENFILE;
887 }
888 
889 
890 int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
891 			 struct module *module, struct device *device,
892 			 short *adapter_nums)
893 {
894 	int i, num;
895 
896 	mutex_lock(&dvbdev_register_lock);
897 
898 	for (i = 0; i < DVB_MAX_ADAPTERS; ++i) {
899 		num = adapter_nums[i];
900 		if (num >= 0  &&  num < DVB_MAX_ADAPTERS) {
901 		/* use the one the driver asked for */
902 			if (dvbdev_check_free_adapter_num(num))
903 				break;
904 		} else {
905 			num = dvbdev_get_free_adapter_num();
906 			break;
907 		}
908 		num = -1;
909 	}
910 
911 	if (num < 0) {
912 		mutex_unlock(&dvbdev_register_lock);
913 		return -ENFILE;
914 	}
915 
916 	memset (adap, 0, sizeof(struct dvb_adapter));
917 	INIT_LIST_HEAD (&adap->device_list);
918 
919 	pr_info("DVB: registering new adapter (%s)\n", name);
920 
921 	adap->num = num;
922 	adap->name = name;
923 	adap->module = module;
924 	adap->device = device;
925 	adap->mfe_shared = 0;
926 	adap->mfe_dvbdev = NULL;
927 	mutex_init (&adap->mfe_lock);
928 
929 #ifdef CONFIG_MEDIA_CONTROLLER_DVB
930 	mutex_init(&adap->mdev_lock);
931 #endif
932 
933 	list_add_tail (&adap->list_head, &dvb_adapter_list);
934 
935 	mutex_unlock(&dvbdev_register_lock);
936 
937 	return num;
938 }
939 EXPORT_SYMBOL(dvb_register_adapter);
940 
941 
942 int dvb_unregister_adapter(struct dvb_adapter *adap)
943 {
944 	mutex_lock(&dvbdev_register_lock);
945 	list_del (&adap->list_head);
946 	mutex_unlock(&dvbdev_register_lock);
947 	return 0;
948 }
949 EXPORT_SYMBOL(dvb_unregister_adapter);
950 
951 /* if the miracle happens and "generic_usercopy()" is included into
952    the kernel, then this can vanish. please don't make the mistake and
953    define this as video_usercopy(). this will introduce a dependency
954    to the v4l "videodev.o" module, which is unnecessary for some
955    cards (ie. the budget dvb-cards don't need the v4l module...) */
956 int dvb_usercopy(struct file *file,
957 		     unsigned int cmd, unsigned long arg,
958 		     int (*func)(struct file *file,
959 		     unsigned int cmd, void *arg))
960 {
961 	char    sbuf[128];
962 	void    *mbuf = NULL;
963 	void    *parg = NULL;
964 	int     err  = -EINVAL;
965 
966 	/*  Copy arguments into temp kernel buffer  */
967 	switch (_IOC_DIR(cmd)) {
968 	case _IOC_NONE:
969 		/*
970 		 * For this command, the pointer is actually an integer
971 		 * argument.
972 		 */
973 		parg = (void *) arg;
974 		break;
975 	case _IOC_READ: /* some v4l ioctls are marked wrong ... */
976 	case _IOC_WRITE:
977 	case (_IOC_WRITE | _IOC_READ):
978 		if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
979 			parg = sbuf;
980 		} else {
981 			/* too big to allocate from stack */
982 			mbuf = kmalloc(_IOC_SIZE(cmd), GFP_KERNEL);
983 			if (NULL == mbuf)
984 				return -ENOMEM;
985 			parg = mbuf;
986 		}
987 
988 		err = -EFAULT;
989 		if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
990 			goto out;
991 		break;
992 	}
993 
994 	/* call driver */
995 	if ((err = func(file, cmd, parg)) == -ENOIOCTLCMD)
996 		err = -ENOTTY;
997 
998 	if (err < 0)
999 		goto out;
1000 
1001 	/*  Copy results into user buffer  */
1002 	switch (_IOC_DIR(cmd))
1003 	{
1004 	case _IOC_READ:
1005 	case (_IOC_WRITE | _IOC_READ):
1006 		if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
1007 			err = -EFAULT;
1008 		break;
1009 	}
1010 
1011 out:
1012 	kfree(mbuf);
1013 	return err;
1014 }
1015 
1016 #if IS_ENABLED(CONFIG_I2C)
1017 struct i2c_client *dvb_module_probe(const char *module_name,
1018 				    const char *name,
1019 				    struct i2c_adapter *adap,
1020 				    unsigned char addr,
1021 				    void *platform_data)
1022 {
1023 	struct i2c_client *client;
1024 	struct i2c_board_info *board_info;
1025 
1026 	board_info = kzalloc(sizeof(*board_info), GFP_KERNEL);
1027 	if (!board_info)
1028 		return NULL;
1029 
1030 	if (name)
1031 		strscpy(board_info->type, name, I2C_NAME_SIZE);
1032 	else
1033 		strscpy(board_info->type, module_name, I2C_NAME_SIZE);
1034 
1035 	board_info->addr = addr;
1036 	board_info->platform_data = platform_data;
1037 	request_module(module_name);
1038 	client = i2c_new_client_device(adap, board_info);
1039 	if (!i2c_client_has_driver(client)) {
1040 		kfree(board_info);
1041 		return NULL;
1042 	}
1043 
1044 	if (!try_module_get(client->dev.driver->owner)) {
1045 		i2c_unregister_device(client);
1046 		client = NULL;
1047 	}
1048 
1049 	kfree(board_info);
1050 	return client;
1051 }
1052 EXPORT_SYMBOL_GPL(dvb_module_probe);
1053 
1054 void dvb_module_release(struct i2c_client *client)
1055 {
1056 	if (!client)
1057 		return;
1058 
1059 	module_put(client->dev.driver->owner);
1060 	i2c_unregister_device(client);
1061 }
1062 EXPORT_SYMBOL_GPL(dvb_module_release);
1063 #endif
1064 
1065 static int dvb_uevent(const struct device *dev, struct kobj_uevent_env *env)
1066 {
1067 	const struct dvb_device *dvbdev = dev_get_drvdata(dev);
1068 
1069 	add_uevent_var(env, "DVB_ADAPTER_NUM=%d", dvbdev->adapter->num);
1070 	add_uevent_var(env, "DVB_DEVICE_TYPE=%s", dnames[dvbdev->type]);
1071 	add_uevent_var(env, "DVB_DEVICE_NUM=%d", dvbdev->id);
1072 	return 0;
1073 }
1074 
1075 static char *dvb_devnode(const struct device *dev, umode_t *mode)
1076 {
1077 	const struct dvb_device *dvbdev = dev_get_drvdata(dev);
1078 
1079 	return kasprintf(GFP_KERNEL, "dvb/adapter%d/%s%d",
1080 		dvbdev->adapter->num, dnames[dvbdev->type], dvbdev->id);
1081 }
1082 
1083 
1084 static int __init init_dvbdev(void)
1085 {
1086 	int retval;
1087 	dev_t dev = MKDEV(DVB_MAJOR, 0);
1088 
1089 	if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
1090 		pr_err("dvb-core: unable to get major %d\n", DVB_MAJOR);
1091 		return retval;
1092 	}
1093 
1094 	cdev_init(&dvb_device_cdev, &dvb_device_fops);
1095 	if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
1096 		pr_err("dvb-core: unable register character device\n");
1097 		goto error;
1098 	}
1099 
1100 	dvb_class = class_create("dvb");
1101 	if (IS_ERR(dvb_class)) {
1102 		retval = PTR_ERR(dvb_class);
1103 		goto error;
1104 	}
1105 	dvb_class->dev_uevent = dvb_uevent;
1106 	dvb_class->devnode = dvb_devnode;
1107 	return 0;
1108 
1109 error:
1110 	cdev_del(&dvb_device_cdev);
1111 	unregister_chrdev_region(dev, MAX_DVB_MINORS);
1112 	return retval;
1113 }
1114 
1115 
1116 static void __exit exit_dvbdev(void)
1117 {
1118 	struct dvbdevfops_node *node, *next;
1119 
1120 	class_destroy(dvb_class);
1121 	cdev_del(&dvb_device_cdev);
1122 	unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
1123 
1124 	list_for_each_entry_safe(node, next, &dvbdevfops_list, list_head) {
1125 		list_del (&node->list_head);
1126 		kfree(node->fops);
1127 		kfree(node);
1128 	}
1129 }
1130 
1131 subsys_initcall(init_dvbdev);
1132 module_exit(exit_dvbdev);
1133 
1134 MODULE_DESCRIPTION("DVB Core Driver");
1135 MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
1136 MODULE_LICENSE("GPL");
1137