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29#include <linux/kernel.h>
30#include <linux/module.h>
31#include <linux/fs.h>
32#include <linux/slab.h>
33#include <linux/init.h>
34#include <linux/list.h>
35#include <linux/i2c.h>
36#include <linux/i2c-dev.h>
37#include <linux/smp_lock.h>
38#include <linux/jiffies.h>
39#include <asm/uaccess.h>
40
41static struct i2c_driver i2cdev_driver;
42
43
44
45
46
47
48
49
50
51
52struct i2c_dev {
53 struct list_head list;
54 struct i2c_adapter *adap;
55 struct device *dev;
56};
57
58#define I2C_MINORS 256
59static LIST_HEAD(i2c_dev_list);
60static DEFINE_SPINLOCK(i2c_dev_list_lock);
61
62static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
63{
64 struct i2c_dev *i2c_dev;
65
66 spin_lock(&i2c_dev_list_lock);
67 list_for_each_entry(i2c_dev, &i2c_dev_list, list) {
68 if (i2c_dev->adap->nr == index)
69 goto found;
70 }
71 i2c_dev = NULL;
72found:
73 spin_unlock(&i2c_dev_list_lock);
74 return i2c_dev;
75}
76
77static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
78{
79 struct i2c_dev *i2c_dev;
80
81 if (adap->nr >= I2C_MINORS) {
82 printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
83 adap->nr);
84 return ERR_PTR(-ENODEV);
85 }
86
87 i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
88 if (!i2c_dev)
89 return ERR_PTR(-ENOMEM);
90 i2c_dev->adap = adap;
91
92 spin_lock(&i2c_dev_list_lock);
93 list_add_tail(&i2c_dev->list, &i2c_dev_list);
94 spin_unlock(&i2c_dev_list_lock);
95 return i2c_dev;
96}
97
98static void return_i2c_dev(struct i2c_dev *i2c_dev)
99{
100 spin_lock(&i2c_dev_list_lock);
101 list_del(&i2c_dev->list);
102 spin_unlock(&i2c_dev_list_lock);
103 kfree(i2c_dev);
104}
105
106static ssize_t show_adapter_name(struct device *dev,
107 struct device_attribute *attr, char *buf)
108{
109 struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt));
110
111 if (!i2c_dev)
112 return -ENODEV;
113 return sprintf(buf, "%s\n", i2c_dev->adap->name);
114}
115static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
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 = (struct i2c_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->f_path.dentry->d_inode), 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, size_t count,
162 loff_t *offset)
163{
164 int ret;
165 char *tmp;
166 struct i2c_client *client = (struct i2c_client *)file->private_data;
167
168 if (count > 8192)
169 count = 8192;
170
171 tmp = kmalloc(count,GFP_KERNEL);
172 if (tmp==NULL)
173 return -ENOMEM;
174 if (copy_from_user(tmp,buf,count)) {
175 kfree(tmp);
176 return -EFAULT;
177 }
178
179 pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n",
180 iminor(file->f_path.dentry->d_inode), count);
181
182 ret = i2c_master_send(client,tmp,count);
183 kfree(tmp);
184 return ret;
185}
186
187static int i2cdev_check(struct device *dev, void *addrp)
188{
189 struct i2c_client *client = i2c_verify_client(dev);
190
191 if (!client || client->addr != *(unsigned int *)addrp)
192 return 0;
193
194 return dev->driver ? -EBUSY : 0;
195}
196
197
198
199
200static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
201{
202 return device_for_each_child(&adapter->dev, &addr, i2cdev_check);
203}
204
205static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
206 unsigned long arg)
207{
208 struct i2c_rdwr_ioctl_data rdwr_arg;
209 struct i2c_msg *rdwr_pa;
210 u8 __user **data_ptrs;
211 int i, res;
212
213 if (copy_from_user(&rdwr_arg,
214 (struct i2c_rdwr_ioctl_data __user *)arg,
215 sizeof(rdwr_arg)))
216 return -EFAULT;
217
218
219
220 if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
221 return -EINVAL;
222
223 rdwr_pa = (struct i2c_msg *)
224 kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
225 GFP_KERNEL);
226 if (!rdwr_pa)
227 return -ENOMEM;
228
229 if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
230 rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
231 kfree(rdwr_pa);
232 return -EFAULT;
233 }
234
235 data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
236 if (data_ptrs == NULL) {
237 kfree(rdwr_pa);
238 return -ENOMEM;
239 }
240
241 res = 0;
242 for (i = 0; i < rdwr_arg.nmsgs; i++) {
243
244
245 if ((rdwr_pa[i].len > 8192) ||
246 (rdwr_pa[i].flags & I2C_M_RECV_LEN)) {
247 res = -EINVAL;
248 break;
249 }
250 data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
251 rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
252 if (rdwr_pa[i].buf == NULL) {
253 res = -ENOMEM;
254 break;
255 }
256 if (copy_from_user(rdwr_pa[i].buf, data_ptrs[i],
257 rdwr_pa[i].len)) {
258 ++i;
259 res = -EFAULT;
260 break;
261 }
262 }
263 if (res < 0) {
264 int j;
265 for (j = 0; j < i; ++j)
266 kfree(rdwr_pa[j].buf);
267 kfree(data_ptrs);
268 kfree(rdwr_pa);
269 return res;
270 }
271
272 res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs);
273 while (i-- > 0) {
274 if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) {
275 if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf,
276 rdwr_pa[i].len))
277 res = -EFAULT;
278 }
279 kfree(rdwr_pa[i].buf);
280 }
281 kfree(data_ptrs);
282 kfree(rdwr_pa);
283 return res;
284}
285
286static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
287 unsigned long arg)
288{
289 struct i2c_smbus_ioctl_data data_arg;
290 union i2c_smbus_data temp;
291 int datasize, res;
292
293 if (copy_from_user(&data_arg,
294 (struct i2c_smbus_ioctl_data __user *) arg,
295 sizeof(struct i2c_smbus_ioctl_data)))
296 return -EFAULT;
297 if ((data_arg.size != I2C_SMBUS_BYTE) &&
298 (data_arg.size != I2C_SMBUS_QUICK) &&
299 (data_arg.size != I2C_SMBUS_BYTE_DATA) &&
300 (data_arg.size != I2C_SMBUS_WORD_DATA) &&
301 (data_arg.size != I2C_SMBUS_PROC_CALL) &&
302 (data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
303 (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
304 (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
305 (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
306 dev_dbg(&client->adapter->dev,
307 "size out of range (%x) in ioctl I2C_SMBUS.\n",
308 data_arg.size);
309 return -EINVAL;
310 }
311
312
313 if ((data_arg.read_write != I2C_SMBUS_READ) &&
314 (data_arg.read_write != I2C_SMBUS_WRITE)) {
315 dev_dbg(&client->adapter->dev,
316 "read_write out of range (%x) in ioctl I2C_SMBUS.\n",
317 data_arg.read_write);
318 return -EINVAL;
319 }
320
321
322
323 if ((data_arg.size == I2C_SMBUS_QUICK) ||
324 ((data_arg.size == I2C_SMBUS_BYTE) &&
325 (data_arg.read_write == I2C_SMBUS_WRITE)))
326
327 return i2c_smbus_xfer(client->adapter, client->addr,
328 client->flags, data_arg.read_write,
329 data_arg.command, data_arg.size, NULL);
330
331 if (data_arg.data == NULL) {
332 dev_dbg(&client->adapter->dev,
333 "data is NULL pointer in ioctl I2C_SMBUS.\n");
334 return -EINVAL;
335 }
336
337 if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
338 (data_arg.size == I2C_SMBUS_BYTE))
339 datasize = sizeof(data_arg.data->byte);
340 else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
341 (data_arg.size == I2C_SMBUS_PROC_CALL))
342 datasize = sizeof(data_arg.data->word);
343 else
344 datasize = sizeof(data_arg.data->block);
345
346 if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
347 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
348 (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
349 (data_arg.read_write == I2C_SMBUS_WRITE)) {
350 if (copy_from_user(&temp, data_arg.data, datasize))
351 return -EFAULT;
352 }
353 if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
354
355
356 data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
357 if (data_arg.read_write == I2C_SMBUS_READ)
358 temp.block[0] = I2C_SMBUS_BLOCK_MAX;
359 }
360 res = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
361 data_arg.read_write, data_arg.command, data_arg.size, &temp);
362 if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
363 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
364 (data_arg.read_write == I2C_SMBUS_READ))) {
365 if (copy_to_user(data_arg.data, &temp, datasize))
366 return -EFAULT;
367 }
368 return res;
369}
370
371static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
372{
373 struct i2c_client *client = (struct i2c_client *)file->private_data;
374 unsigned long funcs;
375
376 dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
377 cmd, arg);
378
379 switch ( cmd ) {
380 case I2C_SLAVE:
381 case I2C_SLAVE_FORCE:
382
383
384
385
386
387
388
389
390
391
392 if ((arg > 0x3ff) ||
393 (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
394 return -EINVAL;
395 if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg))
396 return -EBUSY;
397
398 client->addr = arg;
399 return 0;
400 case I2C_TENBIT:
401 if (arg)
402 client->flags |= I2C_M_TEN;
403 else
404 client->flags &= ~I2C_M_TEN;
405 return 0;
406 case I2C_PEC:
407 if (arg)
408 client->flags |= I2C_CLIENT_PEC;
409 else
410 client->flags &= ~I2C_CLIENT_PEC;
411 return 0;
412 case I2C_FUNCS:
413 funcs = i2c_get_functionality(client->adapter);
414 return put_user(funcs, (unsigned long __user *)arg);
415
416 case I2C_RDWR:
417 return i2cdev_ioctl_rdrw(client, arg);
418
419 case I2C_SMBUS:
420 return i2cdev_ioctl_smbus(client, arg);
421
422 case I2C_RETRIES:
423 client->adapter->retries = arg;
424 break;
425 case I2C_TIMEOUT:
426
427
428
429 client->adapter->timeout = msecs_to_jiffies(arg * 10);
430 break;
431 default:
432
433
434
435
436
437 return -ENOTTY;
438 }
439 return 0;
440}
441
442static int i2cdev_open(struct inode *inode, struct file *file)
443{
444 unsigned int minor = iminor(inode);
445 struct i2c_client *client;
446 struct i2c_adapter *adap;
447 struct i2c_dev *i2c_dev;
448 int ret = 0;
449
450 lock_kernel();
451 i2c_dev = i2c_dev_get_by_minor(minor);
452 if (!i2c_dev) {
453 ret = -ENODEV;
454 goto out;
455 }
456
457 adap = i2c_get_adapter(i2c_dev->adap->nr);
458 if (!adap) {
459 ret = -ENODEV;
460 goto out;
461 }
462
463
464
465
466
467
468
469
470 client = kzalloc(sizeof(*client), GFP_KERNEL);
471 if (!client) {
472 i2c_put_adapter(adap);
473 ret = -ENOMEM;
474 goto out;
475 }
476 snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
477 client->driver = &i2cdev_driver;
478
479 client->adapter = adap;
480 file->private_data = client;
481
482out:
483 unlock_kernel();
484 return ret;
485}
486
487static int i2cdev_release(struct inode *inode, struct file *file)
488{
489 struct i2c_client *client = file->private_data;
490
491 i2c_put_adapter(client->adapter);
492 kfree(client);
493 file->private_data = NULL;
494
495 return 0;
496}
497
498static const struct file_operations i2cdev_fops = {
499 .owner = THIS_MODULE,
500 .llseek = no_llseek,
501 .read = i2cdev_read,
502 .write = i2cdev_write,
503 .unlocked_ioctl = i2cdev_ioctl,
504 .open = i2cdev_open,
505 .release = i2cdev_release,
506};
507
508
509
510
511
512
513
514
515
516static struct class *i2c_dev_class;
517
518static int i2cdev_attach_adapter(struct i2c_adapter *adap)
519{
520 struct i2c_dev *i2c_dev;
521 int res;
522
523 i2c_dev = get_free_i2c_dev(adap);
524 if (IS_ERR(i2c_dev))
525 return PTR_ERR(i2c_dev);
526
527
528 i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
529 MKDEV(I2C_MAJOR, adap->nr), NULL,
530 "i2c-%d", adap->nr);
531 if (IS_ERR(i2c_dev->dev)) {
532 res = PTR_ERR(i2c_dev->dev);
533 goto error;
534 }
535 res = device_create_file(i2c_dev->dev, &dev_attr_name);
536 if (res)
537 goto error_destroy;
538
539 pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
540 adap->name, adap->nr);
541 return 0;
542error_destroy:
543 device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
544error:
545 return_i2c_dev(i2c_dev);
546 return res;
547}
548
549static int i2cdev_detach_adapter(struct i2c_adapter *adap)
550{
551 struct i2c_dev *i2c_dev;
552
553 i2c_dev = i2c_dev_get_by_minor(adap->nr);
554 if (!i2c_dev)
555 return 0;
556
557 device_remove_file(i2c_dev->dev, &dev_attr_name);
558 return_i2c_dev(i2c_dev);
559 device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
560
561 pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
562 return 0;
563}
564
565static struct i2c_driver i2cdev_driver = {
566 .driver = {
567 .name = "dev_driver",
568 },
569 .attach_adapter = i2cdev_attach_adapter,
570 .detach_adapter = i2cdev_detach_adapter,
571};
572
573
574
575
576
577
578
579static int __init i2c_dev_init(void)
580{
581 int res;
582
583 printk(KERN_INFO "i2c /dev entries driver\n");
584
585 res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops);
586 if (res)
587 goto out;
588
589 i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
590 if (IS_ERR(i2c_dev_class)) {
591 res = PTR_ERR(i2c_dev_class);
592 goto out_unreg_chrdev;
593 }
594
595 res = i2c_add_driver(&i2cdev_driver);
596 if (res)
597 goto out_unreg_class;
598
599 return 0;
600
601out_unreg_class:
602 class_destroy(i2c_dev_class);
603out_unreg_chrdev:
604 unregister_chrdev(I2C_MAJOR, "i2c");
605out:
606 printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
607 return res;
608}
609
610static void __exit i2c_dev_exit(void)
611{
612 i2c_del_driver(&i2cdev_driver);
613 class_destroy(i2c_dev_class);
614 unregister_chrdev(I2C_MAJOR,"i2c");
615}
616
617MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
618 "Simon G. Vogl <simon@tk.uni-linz.ac.at>");
619MODULE_DESCRIPTION("I2C /dev entries driver");
620MODULE_LICENSE("GPL");
621
622module_init(i2c_dev_init);
623module_exit(i2c_dev_exit);
624