Free Electrons

Embedded Linux Experts

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
/*
 * dvbdev.c
 *
 * Copyright (C) 2000 Ralph  Metzler <ralph@convergence.de>
 *                  & Marcus Metzler <marcus@convergence.de>
 *                    for convergence integrated media GmbH
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/mutex.h>
#include "dvbdev.h"

static DEFINE_MUTEX(dvbdev_mutex);
static int dvbdev_debug;

module_param(dvbdev_debug, int, 0644);
MODULE_PARM_DESC(dvbdev_debug, "Turn on/off device debugging (default:off).");

#define dprintk if (dvbdev_debug) printk

static LIST_HEAD(dvb_adapter_list);
static DEFINE_MUTEX(dvbdev_register_lock);

static const char * const dnames[] = {
	"video", "audio", "sec", "frontend", "demux", "dvr", "ca",
	"net", "osd"
};

#ifdef CONFIG_DVB_DYNAMIC_MINORS
#define MAX_DVB_MINORS		256
#define DVB_MAX_IDS		MAX_DVB_MINORS
#else
#define DVB_MAX_IDS		4
#define nums2minor(num,type,id)	((num << 6) | (id << 4) | type)
#define MAX_DVB_MINORS		(DVB_MAX_ADAPTERS*64)
#endif

static struct class *dvb_class;

static struct dvb_device *dvb_minors[MAX_DVB_MINORS];
static DECLARE_RWSEM(minor_rwsem);

static int dvb_device_open(struct inode *inode, struct file *file)
{
	struct dvb_device *dvbdev;

	mutex_lock(&dvbdev_mutex);
	down_read(&minor_rwsem);
	dvbdev = dvb_minors[iminor(inode)];

	if (dvbdev && dvbdev->fops) {
		int err = 0;
		const struct file_operations *old_fops;

		file->private_data = dvbdev;
		old_fops = file->f_op;
		file->f_op = fops_get(dvbdev->fops);
		if (file->f_op == NULL) {
			file->f_op = old_fops;
			goto fail;
		}
		if(file->f_op->open)
			err = file->f_op->open(inode,file);
		if (err) {
			fops_put(file->f_op);
			file->f_op = fops_get(old_fops);
		}
		fops_put(old_fops);
		up_read(&minor_rwsem);
		mutex_unlock(&dvbdev_mutex);
		return err;
	}
fail:
	up_read(&minor_rwsem);
	mutex_unlock(&dvbdev_mutex);
	return -ENODEV;
}


static const struct file_operations dvb_device_fops =
{
	.owner =	THIS_MODULE,
	.open =		dvb_device_open,
	.llseek =	noop_llseek,
};

static struct cdev dvb_device_cdev;

int dvb_generic_open(struct inode *inode, struct file *file)
{
	struct dvb_device *dvbdev = file->private_data;

	if (!dvbdev)
		return -ENODEV;

	if (!dvbdev->users)
		return -EBUSY;

	if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
		if (!dvbdev->readers)
			return -EBUSY;
		dvbdev->readers--;
	} else {
		if (!dvbdev->writers)
			return -EBUSY;
		dvbdev->writers--;
	}

	dvbdev->users--;
	return 0;
}
EXPORT_SYMBOL(dvb_generic_open);


int dvb_generic_release(struct inode *inode, struct file *file)
{
	struct dvb_device *dvbdev = file->private_data;

	if (!dvbdev)
		return -ENODEV;

	if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
		dvbdev->readers++;
	} else {
		dvbdev->writers++;
	}

	dvbdev->users++;
	return 0;
}
EXPORT_SYMBOL(dvb_generic_release);


long dvb_generic_ioctl(struct file *file,
		       unsigned int cmd, unsigned long arg)
{
	struct dvb_device *dvbdev = file->private_data;

	if (!dvbdev)
		return -ENODEV;

	if (!dvbdev->kernel_ioctl)
		return -EINVAL;

	return dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
}
EXPORT_SYMBOL(dvb_generic_ioctl);


static int dvbdev_get_free_id (struct dvb_adapter *adap, int type)
{
	u32 id = 0;

	while (id < DVB_MAX_IDS) {
		struct dvb_device *dev;
		list_for_each_entry(dev, &adap->device_list, list_head)
			if (dev->type == type && dev->id == id)
				goto skip;
		return id;
skip:
		id++;
	}
	return -ENFILE;
}


int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
			const struct dvb_device *template, void *priv, int type)
{
	struct dvb_device *dvbdev;
	struct file_operations *dvbdevfops;
	struct device *clsdev;
	int minor;
	int id;

	mutex_lock(&dvbdev_register_lock);

	if ((id = dvbdev_get_free_id (adap, type)) < 0){
		mutex_unlock(&dvbdev_register_lock);
		*pdvbdev = NULL;
		printk(KERN_ERR "%s: couldn't find free device id\n", __func__);
		return -ENFILE;
	}

	*pdvbdev = dvbdev = kmalloc(sizeof(struct dvb_device), GFP_KERNEL);

	if (!dvbdev){
		mutex_unlock(&dvbdev_register_lock);
		return -ENOMEM;
	}

	dvbdevfops = kzalloc(sizeof(struct file_operations), GFP_KERNEL);

	if (!dvbdevfops){
		kfree (dvbdev);
		mutex_unlock(&dvbdev_register_lock);
		return -ENOMEM;
	}

	memcpy(dvbdev, template, sizeof(struct dvb_device));
	dvbdev->type = type;
	dvbdev->id = id;
	dvbdev->adapter = adap;
	dvbdev->priv = priv;
	dvbdev->fops = dvbdevfops;
	init_waitqueue_head (&dvbdev->wait_queue);

	memcpy(dvbdevfops, template->fops, sizeof(struct file_operations));
	dvbdevfops->owner = adap->module;

	list_add_tail (&dvbdev->list_head, &adap->device_list);

	down_write(&minor_rwsem);
#ifdef CONFIG_DVB_DYNAMIC_MINORS
	for (minor = 0; minor < MAX_DVB_MINORS; minor++)
		if (dvb_minors[minor] == NULL)
			break;

	if (minor == MAX_DVB_MINORS) {
		kfree(dvbdevfops);
		kfree(dvbdev);
		mutex_unlock(&dvbdev_register_lock);
		return -EINVAL;
	}
#else
	minor = nums2minor(adap->num, type, id);
#endif

	dvbdev->minor = minor;
	dvb_minors[minor] = dvbdev;
	up_write(&minor_rwsem);

	mutex_unlock(&dvbdev_register_lock);

	clsdev = device_create(dvb_class, adap->device,
			       MKDEV(DVB_MAJOR, minor),
			       dvbdev, "dvb%d.%s%d", adap->num, dnames[type], id);
	if (IS_ERR(clsdev)) {
		printk(KERN_ERR "%s: failed to create device dvb%d.%s%d (%ld)\n",
		       __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
		return PTR_ERR(clsdev);
	}

	dprintk(KERN_DEBUG "DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
		adap->num, dnames[type], id, minor, minor);

	return 0;
}
EXPORT_SYMBOL(dvb_register_device);


void dvb_unregister_device(struct dvb_device *dvbdev)
{
	if (!dvbdev)
		return;

	down_write(&minor_rwsem);
	dvb_minors[dvbdev->minor] = NULL;
	up_write(&minor_rwsem);

	device_destroy(dvb_class, MKDEV(DVB_MAJOR, dvbdev->minor));

	list_del (&dvbdev->list_head);
	kfree (dvbdev->fops);
	kfree (dvbdev);
}
EXPORT_SYMBOL(dvb_unregister_device);

static int dvbdev_check_free_adapter_num(int num)
{
	struct list_head *entry;
	list_for_each(entry, &dvb_adapter_list) {
		struct dvb_adapter *adap;
		adap = list_entry(entry, struct dvb_adapter, list_head);
		if (adap->num == num)
			return 0;
	}
	return 1;
}

static int dvbdev_get_free_adapter_num (void)
{
	int num = 0;

	while (num < DVB_MAX_ADAPTERS) {
		if (dvbdev_check_free_adapter_num(num))
			return num;
		num++;
	}

	return -ENFILE;
}


int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
			 struct module *module, struct device *device,
			 short *adapter_nums)
{
	int i, num;

	mutex_lock(&dvbdev_register_lock);

	for (i = 0; i < DVB_MAX_ADAPTERS; ++i) {
		num = adapter_nums[i];
		if (num >= 0  &&  num < DVB_MAX_ADAPTERS) {
		/* use the one the driver asked for */
			if (dvbdev_check_free_adapter_num(num))
				break;
		} else {
			num = dvbdev_get_free_adapter_num();
			break;
		}
		num = -1;
	}

	if (num < 0) {
		mutex_unlock(&dvbdev_register_lock);
		return -ENFILE;
	}

	memset (adap, 0, sizeof(struct dvb_adapter));
	INIT_LIST_HEAD (&adap->device_list);

	printk(KERN_INFO "DVB: registering new adapter (%s)\n", name);

	adap->num = num;
	adap->name = name;
	adap->module = module;
	adap->device = device;
	adap->mfe_shared = 0;
	adap->mfe_dvbdev = NULL;
	mutex_init (&adap->mfe_lock);

	list_add_tail (&adap->list_head, &dvb_adapter_list);

	mutex_unlock(&dvbdev_register_lock);

	return num;
}
EXPORT_SYMBOL(dvb_register_adapter);


int dvb_unregister_adapter(struct dvb_adapter *adap)
{
	mutex_lock(&dvbdev_register_lock);
	list_del (&adap->list_head);
	mutex_unlock(&dvbdev_register_lock);
	return 0;
}
EXPORT_SYMBOL(dvb_unregister_adapter);

/* if the miracle happens and "generic_usercopy()" is included into
   the kernel, then this can vanish. please don't make the mistake and
   define this as video_usercopy(). this will introduce a dependecy
   to the v4l "videodev.o" module, which is unnecessary for some
   cards (ie. the budget dvb-cards don't need the v4l module...) */
int dvb_usercopy(struct file *file,
		     unsigned int cmd, unsigned long arg,
		     int (*func)(struct file *file,
		     unsigned int cmd, void *arg))
{
	char    sbuf[128];
	void    *mbuf = NULL;
	void    *parg = NULL;
	int     err  = -EINVAL;

	/*  Copy arguments into temp kernel buffer  */
	switch (_IOC_DIR(cmd)) {
	case _IOC_NONE:
		/*
		 * For this command, the pointer is actually an integer
		 * argument.
		 */
		parg = (void *) arg;
		break;
	case _IOC_READ: /* some v4l ioctls are marked wrong ... */
	case _IOC_WRITE:
	case (_IOC_WRITE | _IOC_READ):
		if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
			parg = sbuf;
		} else {
			/* too big to allocate from stack */
			mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
			if (NULL == mbuf)
				return -ENOMEM;
			parg = mbuf;
		}

		err = -EFAULT;
		if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
			goto out;
		break;
	}

	/* call driver */
	mutex_lock(&dvbdev_mutex);
	if ((err = func(file, cmd, parg)) == -ENOIOCTLCMD)
		err = -EINVAL;
	mutex_unlock(&dvbdev_mutex);

	if (err < 0)
		goto out;

	/*  Copy results into user buffer  */
	switch (_IOC_DIR(cmd))
	{
	case _IOC_READ:
	case (_IOC_WRITE | _IOC_READ):
		if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
			err = -EFAULT;
		break;
	}

out:
	kfree(mbuf);
	return err;
}

static int dvb_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	struct dvb_device *dvbdev = dev_get_drvdata(dev);

	add_uevent_var(env, "DVB_ADAPTER_NUM=%d", dvbdev->adapter->num);
	add_uevent_var(env, "DVB_DEVICE_TYPE=%s", dnames[dvbdev->type]);
	add_uevent_var(env, "DVB_DEVICE_NUM=%d", dvbdev->id);
	return 0;
}

static char *dvb_devnode(struct device *dev, umode_t *mode)
{
	struct dvb_device *dvbdev = dev_get_drvdata(dev);

	return kasprintf(GFP_KERNEL, "dvb/adapter%d/%s%d",
		dvbdev->adapter->num, dnames[dvbdev->type], dvbdev->id);
}


static int __init init_dvbdev(void)
{
	int retval;
	dev_t dev = MKDEV(DVB_MAJOR, 0);

	if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
		printk(KERN_ERR "dvb-core: unable to get major %d\n", DVB_MAJOR);
		return retval;
	}

	cdev_init(&dvb_device_cdev, &dvb_device_fops);
	if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
		printk(KERN_ERR "dvb-core: unable register character device\n");
		goto error;
	}

	dvb_class = class_create(THIS_MODULE, "dvb");
	if (IS_ERR(dvb_class)) {
		retval = PTR_ERR(dvb_class);
		goto error;
	}
	dvb_class->dev_uevent = dvb_uevent;
	dvb_class->devnode = dvb_devnode;
	return 0;

error:
	cdev_del(&dvb_device_cdev);
	unregister_chrdev_region(dev, MAX_DVB_MINORS);
	return retval;
}


static void __exit exit_dvbdev(void)
{
	class_destroy(dvb_class);
	cdev_del(&dvb_device_cdev);
	unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
}

subsys_initcall(init_dvbdev);
module_exit(exit_dvbdev);

MODULE_DESCRIPTION("DVB Core Driver");
MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
MODULE_LICENSE("GPL");