1/*
2    i2c-dev.c - i2c-bus driver, char device interface
3
4    Copyright (C) 1995-97 Simon G. Vogl
5    Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
6    Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
7
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 2 of the License, or
11    (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
19/* Note that this is a complete rewrite of Simon Vogl's i2c-dev module.
20   But I have used so much of his original code and ideas that it seems
21   only fair to recognize him as co-author -- Frodo */
22
23/* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */
24
25#include <linux/kernel.h>
26#include <linux/module.h>
27#include <linux/device.h>
28#include <linux/notifier.h>
29#include <linux/fs.h>
30#include <linux/slab.h>
31#include <linux/init.h>
32#include <linux/list.h>
33#include <linux/i2c.h>
34#include <linux/i2c-dev.h>
35#include <linux/jiffies.h>
36#include <linux/uaccess.h>
37
38/*
39 * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a
40 * slave (i2c_client) with which messages will be exchanged.  It's coupled
41 * with a character special file which is accessed by user mode drivers.
42 *
43 * The list of i2c_dev structures is parallel to the i2c_adapter lists
44 * maintained by the driver model, and is updated using bus notifications.
45 */
46struct i2c_dev {
47	struct list_head list;
48	struct i2c_adapter *adap;
49	struct device *dev;
50};
51
52#define I2C_MINORS	256
53static LIST_HEAD(i2c_dev_list);
54static DEFINE_SPINLOCK(i2c_dev_list_lock);
55
56static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
57{
58	struct i2c_dev *i2c_dev;
59
60	spin_lock(&i2c_dev_list_lock);
61	list_for_each_entry(i2c_dev, &i2c_dev_list, list) {
62		if (i2c_dev->adap->nr == index)
63			goto found;
64	}
65	i2c_dev = NULL;
66found:
67	spin_unlock(&i2c_dev_list_lock);
68	return i2c_dev;
69}
70
71static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
72{
73	struct i2c_dev *i2c_dev;
74
75	if (adap->nr >= I2C_MINORS) {
76		printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
77		       adap->nr);
78		return ERR_PTR(-ENODEV);
79	}
80
81	i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
82	if (!i2c_dev)
83		return ERR_PTR(-ENOMEM);
84	i2c_dev->adap = adap;
85
86	spin_lock(&i2c_dev_list_lock);
87	list_add_tail(&i2c_dev->list, &i2c_dev_list);
88	spin_unlock(&i2c_dev_list_lock);
89	return i2c_dev;
90}
91
92static void return_i2c_dev(struct i2c_dev *i2c_dev)
93{
94	spin_lock(&i2c_dev_list_lock);
95	list_del(&i2c_dev->list);
96	spin_unlock(&i2c_dev_list_lock);
97	kfree(i2c_dev);
98}
99
100static ssize_t name_show(struct device *dev,
101			 struct device_attribute *attr, char *buf)
102{
103	struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt));
104
105	if (!i2c_dev)
106		return -ENODEV;
107	return sprintf(buf, "%s\n", i2c_dev->adap->name);
108}
109static DEVICE_ATTR_RO(name);
110
111static struct attribute *i2c_attrs[] = {
112	&dev_attr_name.attr,
113	NULL,
114};
115ATTRIBUTE_GROUPS(i2c);
116
117/* ------------------------------------------------------------------------- */
118
119/*
120 * After opening an instance of this character special file, a file
121 * descriptor starts out associated only with an i2c_adapter (and bus).
122 *
123 * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg
124 * traffic to any devices on the bus used by that adapter.  That's because
125 * the i2c_msg vectors embed all the addressing information they need, and
126 * are submitted directly to an i2c_adapter.  However, SMBus-only adapters
127 * don't support that interface.
128 *
129 * To use read()/write() system calls on that file descriptor, or to use
130 * SMBus interfaces (and work with SMBus-only hosts!), you must first issue
131 * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl.  That configures an anonymous
132 * (never registered) i2c_client so it holds the addressing information
133 * needed by those system calls and by this SMBus interface.
134 */
135
136static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count,
137		loff_t *offset)
138{
139	char *tmp;
140	int ret;
141
142	struct i2c_client *client = file->private_data;
143
144	if (count > 8192)
145		count = 8192;
146
147	tmp = kmalloc(count, GFP_KERNEL);
148	if (tmp == NULL)
149		return -ENOMEM;
150
151	pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n",
152		iminor(file_inode(file)), count);
153
154	ret = i2c_master_recv(client, tmp, count);
155	if (ret >= 0)
156		ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret;
157	kfree(tmp);
158	return ret;
159}
160
161static ssize_t i2cdev_write(struct file *file, const char __user *buf,
162		size_t count, loff_t *offset)
163{
164	int ret;
165	char *tmp;
166	struct i2c_client *client = file->private_data;
167
168	if (count > 8192)
169		count = 8192;
170
171	tmp = memdup_user(buf, count);
172	if (IS_ERR(tmp))
173		return PTR_ERR(tmp);
174
175	pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n",
176		iminor(file_inode(file)), count);
177
178	ret = i2c_master_send(client, tmp, count);
179	kfree(tmp);
180	return ret;
181}
182
183static int i2cdev_check(struct device *dev, void *addrp)
184{
185	struct i2c_client *client = i2c_verify_client(dev);
186
187	if (!client || client->addr != *(unsigned int *)addrp)
188		return 0;
189
190	return dev->driver ? -EBUSY : 0;
191}
192
193/* walk up mux tree */
194static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
195{
196	struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
197	int result;
198
199	result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
200	if (!result && parent)
201		result = i2cdev_check_mux_parents(parent, addr);
202
203	return result;
204}
205
206/* recurse down mux tree */
207static int i2cdev_check_mux_children(struct device *dev, void *addrp)
208{
209	int result;
210
211	if (dev->type == &i2c_adapter_type)
212		result = device_for_each_child(dev, addrp,
213						i2cdev_check_mux_children);
214	else
215		result = i2cdev_check(dev, addrp);
216
217	return result;
218}
219
220/* This address checking function differs from the one in i2c-core
221   in that it considers an address with a registered device, but no
222   driver bound to it, as NOT busy. */
223static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
224{
225	struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
226	int result = 0;
227
228	if (parent)
229		result = i2cdev_check_mux_parents(parent, addr);
230
231	if (!result)
232		result = device_for_each_child(&adapter->dev, &addr,
233						i2cdev_check_mux_children);
234
235	return result;
236}
237
238static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
239		unsigned long arg)
240{
241	struct i2c_rdwr_ioctl_data rdwr_arg;
242	struct i2c_msg *rdwr_pa;
243	u8 __user **data_ptrs;
244	int i, res;
245
246	if (copy_from_user(&rdwr_arg,
247			   (struct i2c_rdwr_ioctl_data __user *)arg,
248			   sizeof(rdwr_arg)))
249		return -EFAULT;
250
251	/* Put an arbitrary limit on the number of messages that can
252	 * be sent at once */
253	if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
254		return -EINVAL;
255
256	rdwr_pa = memdup_user(rdwr_arg.msgs,
257			      rdwr_arg.nmsgs * sizeof(struct i2c_msg));
258	if (IS_ERR(rdwr_pa))
259		return PTR_ERR(rdwr_pa);
260
261	data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
262	if (data_ptrs == NULL) {
263		kfree(rdwr_pa);
264		return -ENOMEM;
265	}
266
267	res = 0;
268	for (i = 0; i < rdwr_arg.nmsgs; i++) {
269		/* Limit the size of the message to a sane amount */
270		if (rdwr_pa[i].len > 8192) {
271			res = -EINVAL;
272			break;
273		}
274
275		data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
276		rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len);
277		if (IS_ERR(rdwr_pa[i].buf)) {
278			res = PTR_ERR(rdwr_pa[i].buf);
279			break;
280		}
281
282		/*
283		 * If the message length is received from the slave (similar
284		 * to SMBus block read), we must ensure that the buffer will
285		 * be large enough to cope with a message length of
286		 * I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus
287		 * drivers allow. The first byte in the buffer must be
288		 * pre-filled with the number of extra bytes, which must be
289		 * at least one to hold the message length, but can be
290		 * greater (for example to account for a checksum byte at
291		 * the end of the message.)
292		 */
293		if (rdwr_pa[i].flags & I2C_M_RECV_LEN) {
294			if (!(rdwr_pa[i].flags & I2C_M_RD) ||
295			    rdwr_pa[i].buf[0] < 1 ||
296			    rdwr_pa[i].len < rdwr_pa[i].buf[0] +
297					     I2C_SMBUS_BLOCK_MAX) {
298				res = -EINVAL;
299				break;
300			}
301
302			rdwr_pa[i].len = rdwr_pa[i].buf[0];
303		}
304	}
305	if (res < 0) {
306		int j;
307		for (j = 0; j < i; ++j)
308			kfree(rdwr_pa[j].buf);
309		kfree(data_ptrs);
310		kfree(rdwr_pa);
311		return res;
312	}
313
314	res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs);
315	while (i-- > 0) {
316		if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) {
317			if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf,
318					 rdwr_pa[i].len))
319				res = -EFAULT;
320		}
321		kfree(rdwr_pa[i].buf);
322	}
323	kfree(data_ptrs);
324	kfree(rdwr_pa);
325	return res;
326}
327
328static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
329		unsigned long arg)
330{
331	struct i2c_smbus_ioctl_data data_arg;
332	union i2c_smbus_data temp;
333	int datasize, res;
334
335	if (copy_from_user(&data_arg,
336			   (struct i2c_smbus_ioctl_data __user *) arg,
337			   sizeof(struct i2c_smbus_ioctl_data)))
338		return -EFAULT;
339	if ((data_arg.size != I2C_SMBUS_BYTE) &&
340	    (data_arg.size != I2C_SMBUS_QUICK) &&
341	    (data_arg.size != I2C_SMBUS_BYTE_DATA) &&
342	    (data_arg.size != I2C_SMBUS_WORD_DATA) &&
343	    (data_arg.size != I2C_SMBUS_PROC_CALL) &&
344	    (data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
345	    (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
346	    (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
347	    (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
348		dev_dbg(&client->adapter->dev,
349			"size out of range (%x) in ioctl I2C_SMBUS.\n",
350			data_arg.size);
351		return -EINVAL;
352	}
353	/* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
354	   so the check is valid if size==I2C_SMBUS_QUICK too. */
355	if ((data_arg.read_write != I2C_SMBUS_READ) &&
356	    (data_arg.read_write != I2C_SMBUS_WRITE)) {
357		dev_dbg(&client->adapter->dev,
358			"read_write out of range (%x) in ioctl I2C_SMBUS.\n",
359			data_arg.read_write);
360		return -EINVAL;
361	}
362
363	/* Note that command values are always valid! */
364
365	if ((data_arg.size == I2C_SMBUS_QUICK) ||
366	    ((data_arg.size == I2C_SMBUS_BYTE) &&
367	    (data_arg.read_write == I2C_SMBUS_WRITE)))
368		/* These are special: we do not use data */
369		return i2c_smbus_xfer(client->adapter, client->addr,
370				      client->flags, data_arg.read_write,
371				      data_arg.command, data_arg.size, NULL);
372
373	if (data_arg.data == NULL) {
374		dev_dbg(&client->adapter->dev,
375			"data is NULL pointer in ioctl I2C_SMBUS.\n");
376		return -EINVAL;
377	}
378
379	if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
380	    (data_arg.size == I2C_SMBUS_BYTE))
381		datasize = sizeof(data_arg.data->byte);
382	else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
383		 (data_arg.size == I2C_SMBUS_PROC_CALL))
384		datasize = sizeof(data_arg.data->word);
385	else /* size == smbus block, i2c block, or block proc. call */
386		datasize = sizeof(data_arg.data->block);
387
388	if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
389	    (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
390	    (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
391	    (data_arg.read_write == I2C_SMBUS_WRITE)) {
392		if (copy_from_user(&temp, data_arg.data, datasize))
393			return -EFAULT;
394	}
395	if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
396		/* Convert old I2C block commands to the new
397		   convention. This preserves binary compatibility. */
398		data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
399		if (data_arg.read_write == I2C_SMBUS_READ)
400			temp.block[0] = I2C_SMBUS_BLOCK_MAX;
401	}
402	res = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
403	      data_arg.read_write, data_arg.command, data_arg.size, &temp);
404	if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
405		     (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
406		     (data_arg.read_write == I2C_SMBUS_READ))) {
407		if (copy_to_user(data_arg.data, &temp, datasize))
408			return -EFAULT;
409	}
410	return res;
411}
412
413static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
414{
415	struct i2c_client *client = file->private_data;
416	unsigned long funcs;
417
418	dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
419		cmd, arg);
420
421	switch (cmd) {
422	case I2C_SLAVE:
423	case I2C_SLAVE_FORCE:
424		/* NOTE:  devices set up to work with "new style" drivers
425		 * can't use I2C_SLAVE, even when the device node is not
426		 * bound to a driver.  Only I2C_SLAVE_FORCE will work.
427		 *
428		 * Setting the PEC flag here won't affect kernel drivers,
429		 * which will be using the i2c_client node registered with
430		 * the driver model core.  Likewise, when that client has
431		 * the PEC flag already set, the i2c-dev driver won't see
432		 * (or use) this setting.
433		 */
434		if ((arg > 0x3ff) ||
435		    (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
436			return -EINVAL;
437		if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg))
438			return -EBUSY;
439		/* REVISIT: address could become busy later */
440		client->addr = arg;
441		return 0;
442	case I2C_TENBIT:
443		if (arg)
444			client->flags |= I2C_M_TEN;
445		else
446			client->flags &= ~I2C_M_TEN;
447		return 0;
448	case I2C_PEC:
449		if (arg)
450			client->flags |= I2C_CLIENT_PEC;
451		else
452			client->flags &= ~I2C_CLIENT_PEC;
453		return 0;
454	case I2C_FUNCS:
455		funcs = i2c_get_functionality(client->adapter);
456		return put_user(funcs, (unsigned long __user *)arg);
457
458	case I2C_RDWR:
459		return i2cdev_ioctl_rdrw(client, arg);
460
461	case I2C_SMBUS:
462		return i2cdev_ioctl_smbus(client, arg);
463
464	case I2C_RETRIES:
465		client->adapter->retries = arg;
466		break;
467	case I2C_TIMEOUT:
468		/* For historical reasons, user-space sets the timeout
469		 * value in units of 10 ms.
470		 */
471		client->adapter->timeout = msecs_to_jiffies(arg * 10);
472		break;
473	default:
474		/* NOTE:  returning a fault code here could cause trouble
475		 * in buggy userspace code.  Some old kernel bugs returned
476		 * zero in this case, and userspace code might accidentally
477		 * have depended on that bug.
478		 */
479		return -ENOTTY;
480	}
481	return 0;
482}
483
484static int i2cdev_open(struct inode *inode, struct file *file)
485{
486	unsigned int minor = iminor(inode);
487	struct i2c_client *client;
488	struct i2c_adapter *adap;
489	struct i2c_dev *i2c_dev;
490
491	i2c_dev = i2c_dev_get_by_minor(minor);
492	if (!i2c_dev)
493		return -ENODEV;
494
495	adap = i2c_get_adapter(i2c_dev->adap->nr);
496	if (!adap)
497		return -ENODEV;
498
499	/* This creates an anonymous i2c_client, which may later be
500	 * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE.
501	 *
502	 * This client is ** NEVER REGISTERED ** with the driver model
503	 * or I2C core code!!  It just holds private copies of addressing
504	 * information and maybe a PEC flag.
505	 */
506	client = kzalloc(sizeof(*client), GFP_KERNEL);
507	if (!client) {
508		i2c_put_adapter(adap);
509		return -ENOMEM;
510	}
511	snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
512
513	client->adapter = adap;
514	file->private_data = client;
515
516	return 0;
517}
518
519static int i2cdev_release(struct inode *inode, struct file *file)
520{
521	struct i2c_client *client = file->private_data;
522
523	i2c_put_adapter(client->adapter);
524	kfree(client);
525	file->private_data = NULL;
526
527	return 0;
528}
529
530static const struct file_operations i2cdev_fops = {
531	.owner		= THIS_MODULE,
532	.llseek		= no_llseek,
533	.read		= i2cdev_read,
534	.write		= i2cdev_write,
535	.unlocked_ioctl	= i2cdev_ioctl,
536	.open		= i2cdev_open,
537	.release	= i2cdev_release,
538};
539
540/* ------------------------------------------------------------------------- */
541
542static struct class *i2c_dev_class;
543
544static int i2cdev_attach_adapter(struct device *dev, void *dummy)
545{
546	struct i2c_adapter *adap;
547	struct i2c_dev *i2c_dev;
548	int res;
549
550	if (dev->type != &i2c_adapter_type)
551		return 0;
552	adap = to_i2c_adapter(dev);
553
554	i2c_dev = get_free_i2c_dev(adap);
555	if (IS_ERR(i2c_dev))
556		return PTR_ERR(i2c_dev);
557
558	/* register this i2c device with the driver core */
559	i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
560				     MKDEV(I2C_MAJOR, adap->nr), NULL,
561				     "i2c-%d", adap->nr);
562	if (IS_ERR(i2c_dev->dev)) {
563		res = PTR_ERR(i2c_dev->dev);
564		goto error;
565	}
566
567	pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
568		 adap->name, adap->nr);
569	return 0;
570error:
571	return_i2c_dev(i2c_dev);
572	return res;
573}
574
575static int i2cdev_detach_adapter(struct device *dev, void *dummy)
576{
577	struct i2c_adapter *adap;
578	struct i2c_dev *i2c_dev;
579
580	if (dev->type != &i2c_adapter_type)
581		return 0;
582	adap = to_i2c_adapter(dev);
583
584	i2c_dev = i2c_dev_get_by_minor(adap->nr);
585	if (!i2c_dev) /* attach_adapter must have failed */
586		return 0;
587
588	return_i2c_dev(i2c_dev);
589	device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
590
591	pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
592	return 0;
593}
594
595static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action,
596			 void *data)
597{
598	struct device *dev = data;
599
600	switch (action) {
601	case BUS_NOTIFY_ADD_DEVICE:
602		return i2cdev_attach_adapter(dev, NULL);
603	case BUS_NOTIFY_DEL_DEVICE:
604		return i2cdev_detach_adapter(dev, NULL);
605	}
606
607	return 0;
608}
609
610static struct notifier_block i2cdev_notifier = {
611	.notifier_call = i2cdev_notifier_call,
612};
613
614/* ------------------------------------------------------------------------- */
615
616/*
617 * module load/unload record keeping
618 */
619
620static int __init i2c_dev_init(void)
621{
622	int res;
623
624	printk(KERN_INFO "i2c /dev entries driver\n");
625
626	res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops);
627	if (res)
628		goto out;
629
630	i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
631	if (IS_ERR(i2c_dev_class)) {
632		res = PTR_ERR(i2c_dev_class);
633		goto out_unreg_chrdev;
634	}
635	i2c_dev_class->dev_groups = i2c_groups;
636
637	/* Keep track of adapters which will be added or removed later */
638	res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
639	if (res)
640		goto out_unreg_class;
641
642	/* Bind to already existing adapters right away */
643	i2c_for_each_dev(NULL, i2cdev_attach_adapter);
644
645	return 0;
646
647out_unreg_class:
648	class_destroy(i2c_dev_class);
649out_unreg_chrdev:
650	unregister_chrdev(I2C_MAJOR, "i2c");
651out:
652	printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
653	return res;
654}
655
656static void __exit i2c_dev_exit(void)
657{
658	bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier);
659	i2c_for_each_dev(NULL, i2cdev_detach_adapter);
660	class_destroy(i2c_dev_class);
661	unregister_chrdev(I2C_MAJOR, "i2c");
662}
663
664MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
665		"Simon G. Vogl <simon@tk.uni-linz.ac.at>");
666MODULE_DESCRIPTION("I2C /dev entries driver");
667MODULE_LICENSE("GPL");
668
669module_init(i2c_dev_init);
670module_exit(i2c_dev_exit);
671