consolidate the reassignments of ->f_op in ->open() instances
[deliverable/linux.git] / drivers / media / dvb-core / dvbdev.c
CommitLineData
1da177e4
LT
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>
1da177e4 28#include <linux/kernel.h>
1da177e4
LT
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>
1e4baed3 34#include <linux/mutex.h>
1da177e4
LT
35#include "dvbdev.h"
36
72024f1e 37static DEFINE_MUTEX(dvbdev_mutex);
1da177e4
LT
38static int dvbdev_debug;
39
40module_param(dvbdev_debug, int, 0644);
41MODULE_PARM_DESC(dvbdev_debug, "Turn on/off device debugging (default:off).");
42
43#define dprintk if (dvbdev_debug) printk
44
45static LIST_HEAD(dvb_adapter_list);
1e4baed3 46static DEFINE_MUTEX(dvbdev_register_lock);
1da177e4
LT
47
48static const char * const dnames[] = {
afd1a0c9 49 "video", "audio", "sec", "frontend", "demux", "dvr", "ca",
1da177e4
LT
50 "net", "osd"
51};
52
5dd3f307
AO
53#ifdef CONFIG_DVB_DYNAMIC_MINORS
54#define MAX_DVB_MINORS 256
55#define DVB_MAX_IDS MAX_DVB_MINORS
56#else
1da177e4
LT
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)
5dd3f307 60#endif
1da177e4 61
56b22935 62static struct class *dvb_class;
1da177e4 63
5dd3f307
AO
64static struct dvb_device *dvb_minors[MAX_DVB_MINORS];
65static DECLARE_RWSEM(minor_rwsem);
1da177e4
LT
66
67static int dvb_device_open(struct inode *inode, struct file *file)
68{
69 struct dvb_device *dvbdev;
70
72024f1e 71 mutex_lock(&dvbdev_mutex);
5dd3f307
AO
72 down_read(&minor_rwsem);
73 dvbdev = dvb_minors[iminor(inode)];
1da177e4
LT
74
75 if (dvbdev && dvbdev->fops) {
76 int err = 0;
e84f9e57 77 const struct file_operations *new_fops;
1da177e4 78
e84f9e57
AV
79 new_fops = fops_get(dvbdev->fops);
80 if (!new_fops)
f41ced8f 81 goto fail;
e84f9e57
AV
82 file->private_data = dvbdev;
83 replace_fops(file, new_fops);
84 if (file->f_op->open)
50c25fff 85 err = file->f_op->open(inode,file);
5dd3f307 86 up_read(&minor_rwsem);
72024f1e 87 mutex_unlock(&dvbdev_mutex);
afd1a0c9 88 return err;
1da177e4 89 }
f41ced8f 90fail:
5dd3f307 91 up_read(&minor_rwsem);
72024f1e 92 mutex_unlock(&dvbdev_mutex);
1da177e4
LT
93 return -ENODEV;
94}
95
96
27a643b1 97static const struct file_operations dvb_device_fops =
1da177e4
LT
98{
99 .owner = THIS_MODULE,
100 .open = dvb_device_open,
6038f373 101 .llseek = noop_llseek,
1da177e4
LT
102};
103
7e7654a9 104static struct cdev dvb_device_cdev;
1da177e4
LT
105
106int dvb_generic_open(struct inode *inode, struct file *file)
107{
afd1a0c9 108 struct dvb_device *dvbdev = file->private_data;
1da177e4 109
afd1a0c9
MCC
110 if (!dvbdev)
111 return -ENODEV;
1da177e4
LT
112
113 if (!dvbdev->users)
afd1a0c9 114 return -EBUSY;
1da177e4
LT
115
116 if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
afd1a0c9
MCC
117 if (!dvbdev->readers)
118 return -EBUSY;
1da177e4
LT
119 dvbdev->readers--;
120 } else {
afd1a0c9
MCC
121 if (!dvbdev->writers)
122 return -EBUSY;
1da177e4
LT
123 dvbdev->writers--;
124 }
125
126 dvbdev->users--;
127 return 0;
128}
129EXPORT_SYMBOL(dvb_generic_open);
130
131
132int dvb_generic_release(struct inode *inode, struct file *file)
133{
afd1a0c9 134 struct dvb_device *dvbdev = file->private_data;
1da177e4
LT
135
136 if (!dvbdev)
afd1a0c9 137 return -ENODEV;
1da177e4
LT
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}
148EXPORT_SYMBOL(dvb_generic_release);
149
150
16ef8def
AB
151long dvb_generic_ioctl(struct file *file,
152 unsigned int cmd, unsigned long arg)
1da177e4 153{
afd1a0c9 154 struct dvb_device *dvbdev = file->private_data;
1da177e4 155
afd1a0c9
MCC
156 if (!dvbdev)
157 return -ENODEV;
1da177e4
LT
158
159 if (!dvbdev->kernel_ioctl)
160 return -EINVAL;
161
72024f1e 162 return dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
1da177e4
LT
163}
164EXPORT_SYMBOL(dvb_generic_ioctl);
165
166
167static int dvbdev_get_free_id (struct dvb_adapter *adap, int type)
168{
169 u32 id = 0;
170
171 while (id < DVB_MAX_IDS) {
79482619
TP
172 struct dvb_device *dev;
173 list_for_each_entry(dev, &adap->device_list, list_head)
1da177e4
LT
174 if (dev->type == type && dev->id == id)
175 goto skip;
1da177e4
LT
176 return id;
177skip:
178 id++;
179 }
180 return -ENFILE;
181}
182
183
184int 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;
b6190102 188 struct file_operations *dvbdevfops;
5f553388 189 struct device *clsdev;
5dd3f307 190 int minor;
1da177e4
LT
191 int id;
192
c2788502 193 mutex_lock(&dvbdev_register_lock);
1da177e4 194
b6190102 195 if ((id = dvbdev_get_free_id (adap, type)) < 0){
1e4baed3 196 mutex_unlock(&dvbdev_register_lock);
1da177e4 197 *pdvbdev = NULL;
46b4f7c1 198 printk(KERN_ERR "%s: couldn't find free device id\n", __func__);
1da177e4
LT
199 return -ENFILE;
200 }
201
202 *pdvbdev = dvbdev = kmalloc(sizeof(struct dvb_device), GFP_KERNEL);
203
b6190102
MS
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);
1e4baed3 213 mutex_unlock(&dvbdev_register_lock);
1da177e4
LT
214 return -ENOMEM;
215 }
216
1da177e4
LT
217 memcpy(dvbdev, template, sizeof(struct dvb_device));
218 dvbdev->type = type;
219 dvbdev->id = id;
220 dvbdev->adapter = adap;
221 dvbdev->priv = priv;
b6190102 222 dvbdev->fops = dvbdevfops;
ca5be9cd 223 init_waitqueue_head (&dvbdev->wait_queue);
1da177e4 224
784e29d2
JE
225 memcpy(dvbdevfops, template->fops, sizeof(struct file_operations));
226 dvbdevfops->owner = adap->module;
1da177e4
LT
227
228 list_add_tail (&dvbdev->list_head, &adap->device_list);
229
5dd3f307
AO
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);
82163edc 239 up_write(&minor_rwsem);
5dd3f307
AO
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
f47f4763
AQ
251 mutex_unlock(&dvbdev_register_lock);
252
a9b12619 253 clsdev = device_create(dvb_class, adap->device,
b7496780 254 MKDEV(DVB_MAJOR, minor),
a5f4c0ce 255 dvbdev, "dvb%d.%s%d", adap->num, dnames[type], id);
4abdcf93
SA
256 if (IS_ERR(clsdev)) {
257 printk(KERN_ERR "%s: failed to create device dvb%d.%s%d (%ld)\n",
46b4f7c1 258 __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
4abdcf93
SA
259 return PTR_ERR(clsdev);
260 }
1da177e4 261
900858ec 262 dprintk(KERN_DEBUG "DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
5dd3f307 263 adap->num, dnames[type], id, minor, minor);
1da177e4
LT
264
265 return 0;
266}
267EXPORT_SYMBOL(dvb_register_device);
268
269
270void dvb_unregister_device(struct dvb_device *dvbdev)
271{
272 if (!dvbdev)
273 return;
274
5dd3f307
AO
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));
1da177e4
LT
280
281 list_del (&dvbdev->list_head);
b6190102 282 kfree (dvbdev->fops);
1da177e4
LT
283 kfree (dvbdev);
284}
285EXPORT_SYMBOL(dvb_unregister_device);
286
78e92006
JG
287static 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}
1da177e4
LT
298
299static int dvbdev_get_free_adapter_num (void)
300{
301 int num = 0;
302
303 while (num < DVB_MAX_ADAPTERS) {
78e92006
JG
304 if (dvbdev_check_free_adapter_num(num))
305 return num;
1da177e4
LT
306 num++;
307 }
308
309 return -ENFILE;
310}
311
312
78e92006
JG
313int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
314 struct module *module, struct device *device,
315 short *adapter_nums)
1da177e4 316{
78e92006 317 int i, num;
1da177e4 318
c2788502 319 mutex_lock(&dvbdev_register_lock);
1da177e4 320
78e92006
JG
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) {
1e4baed3 335 mutex_unlock(&dvbdev_register_lock);
1da177e4
LT
336 return -ENFILE;
337 }
338
1da177e4
LT
339 memset (adap, 0, sizeof(struct dvb_adapter));
340 INIT_LIST_HEAD (&adap->device_list);
341
900858ec 342 printk(KERN_INFO "DVB: registering new adapter (%s)\n", name);
1da177e4 343
1da177e4
LT
344 adap->num = num;
345 adap->name = name;
346 adap->module = module;
d09dbf92 347 adap->device = device;
59b1842d
DB
348 adap->mfe_shared = 0;
349 adap->mfe_dvbdev = NULL;
350 mutex_init (&adap->mfe_lock);
1da177e4
LT
351
352 list_add_tail (&adap->list_head, &dvb_adapter_list);
353
1e4baed3 354 mutex_unlock(&dvbdev_register_lock);
1da177e4
LT
355
356 return num;
357}
358EXPORT_SYMBOL(dvb_register_adapter);
359
360
361int dvb_unregister_adapter(struct dvb_adapter *adap)
362{
c2788502 363 mutex_lock(&dvbdev_register_lock);
1da177e4 364 list_del (&adap->list_head);
1e4baed3 365 mutex_unlock(&dvbdev_register_lock);
1da177e4
LT
366 return 0;
367}
368EXPORT_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...) */
16ef8def 375int dvb_usercopy(struct file *file,
afd1a0c9 376 unsigned int cmd, unsigned long arg,
16ef8def 377 int (*func)(struct file *file,
1da177e4
LT
378 unsigned int cmd, void *arg))
379{
afd1a0c9
MCC
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:
1da177e4
LT
388 /*
389 * For this command, the pointer is actually an integer
390 * argument.
391 */
392 parg = (void *) arg;
393 break;
afd1a0c9
MCC
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)) {
50c25fff 398 parg = sbuf;
afd1a0c9 399 } else {
50c25fff
MK
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;
afd1a0c9
MCC
405 }
406
407 err = -EFAULT;
408 if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
50c25fff 409 goto out;
afd1a0c9
MCC
410 break;
411 }
412
413 /* call driver */
16ef8def 414 if ((err = func(file, cmd, parg)) == -ENOIOCTLCMD)
d9751fd0 415 err = -ENOTTY;
afd1a0c9
MCC
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)))
50c25fff 426 err = -EFAULT;
afd1a0c9
MCC
427 break;
428 }
1da177e4
LT
429
430out:
afd1a0c9
MCC
431 kfree(mbuf);
432 return err;
1da177e4
LT
433}
434
a5f4c0ce
KS
435static int dvb_uevent(struct device *dev, struct kobj_uevent_env *env)
436{
437 struct dvb_device *dvbdev = dev_get_drvdata(dev);
438
a5f4c0ce 439 add_uevent_var(env, "DVB_ADAPTER_NUM=%d", dvbdev->adapter->num);
763d19bb
KS
440 add_uevent_var(env, "DVB_DEVICE_TYPE=%s", dnames[dvbdev->type]);
441 add_uevent_var(env, "DVB_DEVICE_NUM=%d", dvbdev->id);
a5f4c0ce
KS
442 return 0;
443}
444
2c9ede55 445static char *dvb_devnode(struct device *dev, umode_t *mode)
8a8bdcc7
KS
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
1da177e4
LT
454static 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) {
900858ec 460 printk(KERN_ERR "dvb-core: unable to get major %d\n", DVB_MAJOR);
1da177e4
LT
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) {
900858ec 466 printk(KERN_ERR "dvb-core: unable register character device\n");
1da177e4
LT
467 goto error;
468 }
469
56b22935 470 dvb_class = class_create(THIS_MODULE, "dvb");
1da177e4
LT
471 if (IS_ERR(dvb_class)) {
472 retval = PTR_ERR(dvb_class);
473 goto error;
474 }
a5f4c0ce 475 dvb_class->dev_uevent = dvb_uevent;
e454cea2 476 dvb_class->devnode = dvb_devnode;
1da177e4
LT
477 return 0;
478
479error:
480 cdev_del(&dvb_device_cdev);
481 unregister_chrdev_region(dev, MAX_DVB_MINORS);
482 return retval;
483}
484
485
486static void __exit exit_dvbdev(void)
487{
56b22935 488 class_destroy(dvb_class);
1da177e4 489 cdev_del(&dvb_device_cdev);
afd1a0c9 490 unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
1da177e4
LT
491}
492
4abdcf93 493subsys_initcall(init_dvbdev);
1da177e4
LT
494module_exit(exit_dvbdev);
495
496MODULE_DESCRIPTION("DVB Core Driver");
497MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
498MODULE_LICENSE("GPL");
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