xref: /openbmc/linux/drivers/media/dvb-core/dvbdev.c (revision 12eb4683) 
1 /*
2  * dvbdev.c
3  *
4  * Copyright (C) 2000 Ralph  Metzler <ralph@convergence.de>
5  *                  & Marcus Metzler <marcus@convergence.de>
6  *                    for convergence integrated media GmbH
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public License
10  * as published by the Free Software Foundation; either version 2.1
11  * of the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
21  *
22  */
23 
24 #include <linux/types.h>
25 #include <linux/errno.h>
26 #include <linux/string.h>
27 #include <linux/module.h>
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/slab.h>
31 #include <linux/device.h>
32 #include <linux/fs.h>
33 #include <linux/cdev.h>
34 #include <linux/mutex.h>
35 #include "dvbdev.h"
36 
37 static DEFINE_MUTEX(dvbdev_mutex);
38 static int dvbdev_debug;
39 
40 module_param(dvbdev_debug, int, 0644);
41 MODULE_PARM_DESC(dvbdev_debug, "Turn on/off device debugging (default:off).");
42 
43 #define dprintk if (dvbdev_debug) printk
44 
45 static LIST_HEAD(dvb_adapter_list);
46 static DEFINE_MUTEX(dvbdev_register_lock);
47 
48 static const char * const dnames[] = {
49 	"video", "audio", "sec", "frontend", "demux", "dvr", "ca",
50 	"net", "osd"
51 };
52 
53 #ifdef CONFIG_DVB_DYNAMIC_MINORS
54 #define MAX_DVB_MINORS		256
55 #define DVB_MAX_IDS		MAX_DVB_MINORS
56 #else
57 #define DVB_MAX_IDS		4
58 #define nums2minor(num,type,id)	((num << 6) | (id << 4) | type)
59 #define MAX_DVB_MINORS		(DVB_MAX_ADAPTERS*64)
60 #endif
61 
62 static struct class *dvb_class;
63 
64 static struct dvb_device *dvb_minors[MAX_DVB_MINORS];
65 static DECLARE_RWSEM(minor_rwsem);
66 
67 static int dvb_device_open(struct inode *inode, struct file *file)
68 {
69 	struct dvb_device *dvbdev;
70 
71 	mutex_lock(&dvbdev_mutex);
72 	down_read(&minor_rwsem);
73 	dvbdev = dvb_minors[iminor(inode)];
74 
75 	if (dvbdev && dvbdev->fops) {
76 		int err = 0;
77 		const struct file_operations *new_fops;
78 
79 		new_fops = fops_get(dvbdev->fops);
80 		if (!new_fops)
81 			goto fail;
82 		file->private_data = dvbdev;
83 		replace_fops(file, new_fops);
84 		if (file->f_op->open)
85 			err = file->f_op->open(inode,file);
86 		up_read(&minor_rwsem);
87 		mutex_unlock(&dvbdev_mutex);
88 		return err;
89 	}
90 fail:
91 	up_read(&minor_rwsem);
92 	mutex_unlock(&dvbdev_mutex);
93 	return -ENODEV;
94 }
95 
96 
97 static const struct file_operations dvb_device_fops =
98 {
99 	.owner =	THIS_MODULE,
100 	.open =		dvb_device_open,
101 	.llseek =	noop_llseek,
102 };
103 
104 static struct cdev dvb_device_cdev;
105 
106 int dvb_generic_open(struct inode *inode, struct file *file)
107 {
108 	struct dvb_device *dvbdev = file->private_data;
109 
110 	if (!dvbdev)
111 		return -ENODEV;
112 
113 	if (!dvbdev->users)
114 		return -EBUSY;
115 
116 	if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
117 		if (!dvbdev->readers)
118 			return -EBUSY;
119 		dvbdev->readers--;
120 	} else {
121 		if (!dvbdev->writers)
122 			return -EBUSY;
123 		dvbdev->writers--;
124 	}
125 
126 	dvbdev->users--;
127 	return 0;
128 }
129 EXPORT_SYMBOL(dvb_generic_open);
130 
131 
132 int dvb_generic_release(struct inode *inode, struct file *file)
133 {
134 	struct dvb_device *dvbdev = file->private_data;
135 
136 	if (!dvbdev)
137 		return -ENODEV;
138 
139 	if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
140 		dvbdev->readers++;
141 	} else {
142 		dvbdev->writers++;
143 	}
144 
145 	dvbdev->users++;
146 	return 0;
147 }
148 EXPORT_SYMBOL(dvb_generic_release);
149 
150 
151 long dvb_generic_ioctl(struct file *file,
152 		       unsigned int cmd, unsigned long arg)
153 {
154 	struct dvb_device *dvbdev = file->private_data;
155 
156 	if (!dvbdev)
157 		return -ENODEV;
158 
159 	if (!dvbdev->kernel_ioctl)
160 		return -EINVAL;
161 
162 	return dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
163 }
164 EXPORT_SYMBOL(dvb_generic_ioctl);
165 
166 
167 static int dvbdev_get_free_id (struct dvb_adapter *adap, int type)
168 {
169 	u32 id = 0;
170 
171 	while (id < DVB_MAX_IDS) {
172 		struct dvb_device *dev;
173 		list_for_each_entry(dev, &adap->device_list, list_head)
174 			if (dev->type == type && dev->id == id)
175 				goto skip;
176 		return id;
177 skip:
178 		id++;
179 	}
180 	return -ENFILE;
181 }
182 
183 
184 int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
185 			const struct dvb_device *template, void *priv, int type)
186 {
187 	struct dvb_device *dvbdev;
188 	struct file_operations *dvbdevfops;
189 	struct device *clsdev;
190 	int minor;
191 	int id;
192 
193 	mutex_lock(&dvbdev_register_lock);
194 
195 	if ((id = dvbdev_get_free_id (adap, type)) < 0){
196 		mutex_unlock(&dvbdev_register_lock);
197 		*pdvbdev = NULL;
198 		printk(KERN_ERR "%s: couldn't find free device id\n", __func__);
199 		return -ENFILE;
200 	}
201 
202 	*pdvbdev = dvbdev = kmalloc(sizeof(struct dvb_device), GFP_KERNEL);
203 
204 	if (!dvbdev){
205 		mutex_unlock(&dvbdev_register_lock);
206 		return -ENOMEM;
207 	}
208 
209 	dvbdevfops = kzalloc(sizeof(struct file_operations), GFP_KERNEL);
210 
211 	if (!dvbdevfops){
212 		kfree (dvbdev);
213 		mutex_unlock(&dvbdev_register_lock);
214 		return -ENOMEM;
215 	}
216 
217 	memcpy(dvbdev, template, sizeof(struct dvb_device));
218 	dvbdev->type = type;
219 	dvbdev->id = id;
220 	dvbdev->adapter = adap;
221 	dvbdev->priv = priv;
222 	dvbdev->fops = dvbdevfops;
223 	init_waitqueue_head (&dvbdev->wait_queue);
224 
225 	memcpy(dvbdevfops, template->fops, sizeof(struct file_operations));
226 	dvbdevfops->owner = adap->module;
227 
228 	list_add_tail (&dvbdev->list_head, &adap->device_list);
229 
230 	down_write(&minor_rwsem);
231 #ifdef CONFIG_DVB_DYNAMIC_MINORS
232 	for (minor = 0; minor < MAX_DVB_MINORS; minor++)
233 		if (dvb_minors[minor] == NULL)
234 			break;
235 
236 	if (minor == MAX_DVB_MINORS) {
237 		kfree(dvbdevfops);
238 		kfree(dvbdev);
239 		up_write(&minor_rwsem);
240 		mutex_unlock(&dvbdev_register_lock);
241 		return -EINVAL;
242 	}
243 #else
244 	minor = nums2minor(adap->num, type, id);
245 #endif
246 
247 	dvbdev->minor = minor;
248 	dvb_minors[minor] = dvbdev;
249 	up_write(&minor_rwsem);
250 
251 	mutex_unlock(&dvbdev_register_lock);
252 
253 	clsdev = device_create(dvb_class, adap->device,
254 			       MKDEV(DVB_MAJOR, minor),
255 			       dvbdev, "dvb%d.%s%d", adap->num, dnames[type], id);
256 	if (IS_ERR(clsdev)) {
257 		printk(KERN_ERR "%s: failed to create device dvb%d.%s%d (%ld)\n",
258 		       __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
259 		return PTR_ERR(clsdev);
260 	}
261 
262 	dprintk(KERN_DEBUG "DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
263 		adap->num, dnames[type], id, minor, minor);
264 
265 	return 0;
266 }
267 EXPORT_SYMBOL(dvb_register_device);
268 
269 
270 void dvb_unregister_device(struct dvb_device *dvbdev)
271 {
272 	if (!dvbdev)
273 		return;
274 
275 	down_write(&minor_rwsem);
276 	dvb_minors[dvbdev->minor] = NULL;
277 	up_write(&minor_rwsem);
278 
279 	device_destroy(dvb_class, MKDEV(DVB_MAJOR, dvbdev->minor));
280 
281 	list_del (&dvbdev->list_head);
282 	kfree (dvbdev->fops);
283 	kfree (dvbdev);
284 }
285 EXPORT_SYMBOL(dvb_unregister_device);
286 
287 static int dvbdev_check_free_adapter_num(int num)
288 {
289 	struct list_head *entry;
290 	list_for_each(entry, &dvb_adapter_list) {
291 		struct dvb_adapter *adap;
292 		adap = list_entry(entry, struct dvb_adapter, list_head);
293 		if (adap->num == num)
294 			return 0;
295 	}
296 	return 1;
297 }
298 
299 static int dvbdev_get_free_adapter_num (void)
300 {
301 	int num = 0;
302 
303 	while (num < DVB_MAX_ADAPTERS) {
304 		if (dvbdev_check_free_adapter_num(num))
305 			return num;
306 		num++;
307 	}
308 
309 	return -ENFILE;
310 }
311 
312 
313 int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
314 			 struct module *module, struct device *device,
315 			 short *adapter_nums)
316 {
317 	int i, num;
318 
319 	mutex_lock(&dvbdev_register_lock);
320 
321 	for (i = 0; i < DVB_MAX_ADAPTERS; ++i) {
322 		num = adapter_nums[i];
323 		if (num >= 0  &&  num < DVB_MAX_ADAPTERS) {
324 		/* use the one the driver asked for */
325 			if (dvbdev_check_free_adapter_num(num))
326 				break;
327 		} else {
328 			num = dvbdev_get_free_adapter_num();
329 			break;
330 		}
331 		num = -1;
332 	}
333 
334 	if (num < 0) {
335 		mutex_unlock(&dvbdev_register_lock);
336 		return -ENFILE;
337 	}
338 
339 	memset (adap, 0, sizeof(struct dvb_adapter));
340 	INIT_LIST_HEAD (&adap->device_list);
341 
342 	printk(KERN_INFO "DVB: registering new adapter (%s)\n", name);
343 
344 	adap->num = num;
345 	adap->name = name;
346 	adap->module = module;
347 	adap->device = device;
348 	adap->mfe_shared = 0;
349 	adap->mfe_dvbdev = NULL;
350 	mutex_init (&adap->mfe_lock);
351 
352 	list_add_tail (&adap->list_head, &dvb_adapter_list);
353 
354 	mutex_unlock(&dvbdev_register_lock);
355 
356 	return num;
357 }
358 EXPORT_SYMBOL(dvb_register_adapter);
359 
360 
361 int dvb_unregister_adapter(struct dvb_adapter *adap)
362 {
363 	mutex_lock(&dvbdev_register_lock);
364 	list_del (&adap->list_head);
365 	mutex_unlock(&dvbdev_register_lock);
366 	return 0;
367 }
368 EXPORT_SYMBOL(dvb_unregister_adapter);
369 
370 /* if the miracle happens and "generic_usercopy()" is included into
371    the kernel, then this can vanish. please don't make the mistake and
372    define this as video_usercopy(). this will introduce a dependecy
373    to the v4l "videodev.o" module, which is unnecessary for some
374    cards (ie. the budget dvb-cards don't need the v4l module...) */
375 int dvb_usercopy(struct file *file,
376 		     unsigned int cmd, unsigned long arg,
377 		     int (*func)(struct file *file,
378 		     unsigned int cmd, void *arg))
379 {
380 	char    sbuf[128];
381 	void    *mbuf = NULL;
382 	void    *parg = NULL;
383 	int     err  = -EINVAL;
384 
385 	/*  Copy arguments into temp kernel buffer  */
386 	switch (_IOC_DIR(cmd)) {
387 	case _IOC_NONE:
388 		/*
389 		 * For this command, the pointer is actually an integer
390 		 * argument.
391 		 */
392 		parg = (void *) arg;
393 		break;
394 	case _IOC_READ: /* some v4l ioctls are marked wrong ... */
395 	case _IOC_WRITE:
396 	case (_IOC_WRITE | _IOC_READ):
397 		if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
398 			parg = sbuf;
399 		} else {
400 			/* too big to allocate from stack */
401 			mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
402 			if (NULL == mbuf)
403 				return -ENOMEM;
404 			parg = mbuf;
405 		}
406 
407 		err = -EFAULT;
408 		if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
409 			goto out;
410 		break;
411 	}
412 
413 	/* call driver */
414 	if ((err = func(file, cmd, parg)) == -ENOIOCTLCMD)
415 		err = -ENOTTY;
416 
417 	if (err < 0)
418 		goto out;
419 
420 	/*  Copy results into user buffer  */
421 	switch (_IOC_DIR(cmd))
422 	{
423 	case _IOC_READ:
424 	case (_IOC_WRITE | _IOC_READ):
425 		if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
426 			err = -EFAULT;
427 		break;
428 	}
429 
430 out:
431 	kfree(mbuf);
432 	return err;
433 }
434 
435 static int dvb_uevent(struct device *dev, struct kobj_uevent_env *env)
436 {
437 	struct dvb_device *dvbdev = dev_get_drvdata(dev);
438 
439 	add_uevent_var(env, "DVB_ADAPTER_NUM=%d", dvbdev->adapter->num);
440 	add_uevent_var(env, "DVB_DEVICE_TYPE=%s", dnames[dvbdev->type]);
441 	add_uevent_var(env, "DVB_DEVICE_NUM=%d", dvbdev->id);
442 	return 0;
443 }
444 
445 static char *dvb_devnode(struct device *dev, umode_t *mode)
446 {
447 	struct dvb_device *dvbdev = dev_get_drvdata(dev);
448 
449 	return kasprintf(GFP_KERNEL, "dvb/adapter%d/%s%d",
450 		dvbdev->adapter->num, dnames[dvbdev->type], dvbdev->id);
451 }
452 
453 
454 static int __init init_dvbdev(void)
455 {
456 	int retval;
457 	dev_t dev = MKDEV(DVB_MAJOR, 0);
458 
459 	if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
460 		printk(KERN_ERR "dvb-core: unable to get major %d\n", DVB_MAJOR);
461 		return retval;
462 	}
463 
464 	cdev_init(&dvb_device_cdev, &dvb_device_fops);
465 	if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
466 		printk(KERN_ERR "dvb-core: unable register character device\n");
467 		goto error;
468 	}
469 
470 	dvb_class = class_create(THIS_MODULE, "dvb");
471 	if (IS_ERR(dvb_class)) {
472 		retval = PTR_ERR(dvb_class);
473 		goto error;
474 	}
475 	dvb_class->dev_uevent = dvb_uevent;
476 	dvb_class->devnode = dvb_devnode;
477 	return 0;
478 
479 error:
480 	cdev_del(&dvb_device_cdev);
481 	unregister_chrdev_region(dev, MAX_DVB_MINORS);
482 	return retval;
483 }
484 
485 
486 static void __exit exit_dvbdev(void)
487 {
488 	class_destroy(dvb_class);
489 	cdev_del(&dvb_device_cdev);
490 	unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
491 }
492 
493 subsys_initcall(init_dvbdev);
494 module_exit(exit_dvbdev);
495 
496 MODULE_DESCRIPTION("DVB Core Driver");
497 MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
498 MODULE_LICENSE("GPL");
499