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29#include <linux/kernel.h>
30#include <linux/module.h>
31#include <linux/device.h>
32#include <linux/notifier.h>
33#include <linux/fs.h>
34#include <linux/slab.h>
35#include <linux/init.h>
36#include <linux/list.h>
37#include <linux/i2c.h>
38#include <linux/i2c-dev.h>
39#include <linux/jiffies.h>
40#include <linux/uaccess.h>
41
42
43
44
45
46
47
48
49
50struct i2c_dev {
51 struct list_head list;
52 struct i2c_adapter *adap;
53 struct device *dev;
54};
55
56#define I2C_MINORS 256
57static LIST_HEAD(i2c_dev_list);
58static DEFINE_SPINLOCK(i2c_dev_list_lock);
59
60static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
61{
62 struct i2c_dev *i2c_dev;
63
64 spin_lock(&i2c_dev_list_lock);
65 list_for_each_entry(i2c_dev, &i2c_dev_list, list) {
66 if (i2c_dev->adap->nr == index)
67 goto found;
68 }
69 i2c_dev = NULL;
70found:
71 spin_unlock(&i2c_dev_list_lock);
72 return i2c_dev;
73}
74
75static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
76{
77 struct i2c_dev *i2c_dev;
78
79 if (adap->nr >= I2C_MINORS) {
80 printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
81 adap->nr);
82 return ERR_PTR(-ENODEV);
83 }
84
85 i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
86 if (!i2c_dev)
87 return ERR_PTR(-ENOMEM);
88 i2c_dev->adap = adap;
89
90 spin_lock(&i2c_dev_list_lock);
91 list_add_tail(&i2c_dev->list, &i2c_dev_list);
92 spin_unlock(&i2c_dev_list_lock);
93 return i2c_dev;
94}
95
96static void return_i2c_dev(struct i2c_dev *i2c_dev)
97{
98 spin_lock(&i2c_dev_list_lock);
99 list_del(&i2c_dev->list);
100 spin_unlock(&i2c_dev_list_lock);
101 kfree(i2c_dev);
102}
103
104static ssize_t show_adapter_name(struct device *dev,
105 struct device_attribute *attr, char *buf)
106{
107 struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt));
108
109 if (!i2c_dev)
110 return -ENODEV;
111 return sprintf(buf, "%s\n", i2c_dev->adap->name);
112}
113static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count,
135 loff_t *offset)
136{
137 char *tmp;
138 int ret;
139
140 struct i2c_client *client = file->private_data;
141
142 if (count > 8192)
143 count = 8192;
144
145 tmp = kmalloc(count, GFP_KERNEL);
146 if (tmp == NULL)
147 return -ENOMEM;
148
149 pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n",
150 iminor(file->f_path.dentry->d_inode), count);
151
152 ret = i2c_master_recv(client, tmp, count);
153 if (ret >= 0)
154 ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret;
155 kfree(tmp);
156 return ret;
157}
158
159static ssize_t i2cdev_write(struct file *file, const char __user *buf,
160 size_t count, loff_t *offset)
161{
162 int ret;
163 char *tmp;
164 struct i2c_client *client = file->private_data;
165
166 if (count > 8192)
167 count = 8192;
168
169 tmp = memdup_user(buf, count);
170 if (IS_ERR(tmp))
171 return PTR_ERR(tmp);
172
173 pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n",
174 iminor(file->f_path.dentry->d_inode), count);
175
176 ret = i2c_master_send(client, tmp, count);
177 kfree(tmp);
178 return ret;
179}
180
181static int i2cdev_check(struct device *dev, void *addrp)
182{
183 struct i2c_client *client = i2c_verify_client(dev);
184
185 if (!client || client->addr != *(unsigned int *)addrp)
186 return 0;
187
188 return dev->driver ? -EBUSY : 0;
189}
190
191
192static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
193{
194 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
195 int result;
196
197 result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
198 if (!result && parent)
199 result = i2cdev_check_mux_parents(parent, addr);
200
201 return result;
202}
203
204
205static int i2cdev_check_mux_children(struct device *dev, void *addrp)
206{
207 int result;
208
209 if (dev->type == &i2c_adapter_type)
210 result = device_for_each_child(dev, addrp,
211 i2cdev_check_mux_children);
212 else
213 result = i2cdev_check(dev, addrp);
214
215 return result;
216}
217
218
219
220
221static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
222{
223 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
224 int result = 0;
225
226 if (parent)
227 result = i2cdev_check_mux_parents(parent, addr);
228
229 if (!result)
230 result = device_for_each_child(&adapter->dev, &addr,
231 i2cdev_check_mux_children);
232
233 return result;
234}
235
236static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
237 unsigned long arg)
238{
239 struct i2c_rdwr_ioctl_data rdwr_arg;
240 struct i2c_msg *rdwr_pa;
241 u8 __user **data_ptrs;
242 int i, res;
243
244 if (copy_from_user(&rdwr_arg,
245 (struct i2c_rdwr_ioctl_data __user *)arg,
246 sizeof(rdwr_arg)))
247 return -EFAULT;
248
249
250
251 if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
252 return -EINVAL;
253
254 rdwr_pa = kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), GFP_KERNEL);
255 if (!rdwr_pa)
256 return -ENOMEM;
257
258 if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
259 rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
260 kfree(rdwr_pa);
261 return -EFAULT;
262 }
263
264 data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
265 if (data_ptrs == NULL) {
266 kfree(rdwr_pa);
267 return -ENOMEM;
268 }
269
270 res = 0;
271 for (i = 0; i < rdwr_arg.nmsgs; i++) {
272
273
274 if ((rdwr_pa[i].len > 8192) ||
275 (rdwr_pa[i].flags & I2C_M_RECV_LEN)) {
276 res = -EINVAL;
277 break;
278 }
279 data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
280 rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len);
281 if (IS_ERR(rdwr_pa[i].buf)) {
282 res = PTR_ERR(rdwr_pa[i].buf);
283 break;
284 }
285 }
286 if (res < 0) {
287 int j;
288 for (j = 0; j < i; ++j)
289 kfree(rdwr_pa[j].buf);
290 kfree(data_ptrs);
291 kfree(rdwr_pa);
292 return res;
293 }
294
295 res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs);
296 while (i-- > 0) {
297 if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) {
298 if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf,
299 rdwr_pa[i].len))
300 res = -EFAULT;
301 }
302 kfree(rdwr_pa[i].buf);
303 }
304 kfree(data_ptrs);
305 kfree(rdwr_pa);
306 return res;
307}
308
309static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
310 unsigned long arg)
311{
312 struct i2c_smbus_ioctl_data data_arg;
313 union i2c_smbus_data temp;
314 int datasize, res;
315
316 if (copy_from_user(&data_arg,
317 (struct i2c_smbus_ioctl_data __user *) arg,
318 sizeof(struct i2c_smbus_ioctl_data)))
319 return -EFAULT;
320 if ((data_arg.size != I2C_SMBUS_BYTE) &&
321 (data_arg.size != I2C_SMBUS_QUICK) &&
322 (data_arg.size != I2C_SMBUS_BYTE_DATA) &&
323 (data_arg.size != I2C_SMBUS_WORD_DATA) &&
324 (data_arg.size != I2C_SMBUS_PROC_CALL) &&
325 (data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
326 (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
327 (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
328 (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
329 dev_dbg(&client->adapter->dev,
330 "size out of range (%x) in ioctl I2C_SMBUS.\n",
331 data_arg.size);
332 return -EINVAL;
333 }
334
335
336 if ((data_arg.read_write != I2C_SMBUS_READ) &&
337 (data_arg.read_write != I2C_SMBUS_WRITE)) {
338 dev_dbg(&client->adapter->dev,
339 "read_write out of range (%x) in ioctl I2C_SMBUS.\n",
340 data_arg.read_write);
341 return -EINVAL;
342 }
343
344
345
346 if ((data_arg.size == I2C_SMBUS_QUICK) ||
347 ((data_arg.size == I2C_SMBUS_BYTE) &&
348 (data_arg.read_write == I2C_SMBUS_WRITE)))
349
350 return i2c_smbus_xfer(client->adapter, client->addr,
351 client->flags, data_arg.read_write,
352 data_arg.command, data_arg.size, NULL);
353
354 if (data_arg.data == NULL) {
355 dev_dbg(&client->adapter->dev,
356 "data is NULL pointer in ioctl I2C_SMBUS.\n");
357 return -EINVAL;
358 }
359
360 if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
361 (data_arg.size == I2C_SMBUS_BYTE))
362 datasize = sizeof(data_arg.data->byte);
363 else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
364 (data_arg.size == I2C_SMBUS_PROC_CALL))
365 datasize = sizeof(data_arg.data->word);
366 else
367 datasize = sizeof(data_arg.data->block);
368
369 if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
370 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
371 (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
372 (data_arg.read_write == I2C_SMBUS_WRITE)) {
373 if (copy_from_user(&temp, data_arg.data, datasize))
374 return -EFAULT;
375 }
376 if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
377
378
379 data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
380 if (data_arg.read_write == I2C_SMBUS_READ)
381 temp.block[0] = I2C_SMBUS_BLOCK_MAX;
382 }
383 res = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
384 data_arg.read_write, data_arg.command, data_arg.size, &temp);
385 if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
386 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
387 (data_arg.read_write == I2C_SMBUS_READ))) {
388 if (copy_to_user(data_arg.data, &temp, datasize))
389 return -EFAULT;
390 }
391 return res;
392}
393
394static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
395{
396 struct i2c_client *client = file->private_data;
397 unsigned long funcs;
398
399 dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
400 cmd, arg);
401
402 switch (cmd) {
403 case I2C_SLAVE:
404 case I2C_SLAVE_FORCE:
405
406
407
408
409
410
411
412
413
414
415 if ((arg > 0x3ff) ||
416 (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
417 return -EINVAL;
418 if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg))
419 return -EBUSY;
420
421 client->addr = arg;
422 return 0;
423 case I2C_TENBIT:
424 if (arg)
425 client->flags |= I2C_M_TEN;
426 else
427 client->flags &= ~I2C_M_TEN;
428 return 0;
429 case I2C_PEC:
430 if (arg)
431 client->flags |= I2C_CLIENT_PEC;
432 else
433 client->flags &= ~I2C_CLIENT_PEC;
434 return 0;
435 case I2C_FUNCS:
436 funcs = i2c_get_functionality(client->adapter);
437 return put_user(funcs, (unsigned long __user *)arg);
438
439 case I2C_RDWR:
440 return i2cdev_ioctl_rdrw(client, arg);
441
442 case I2C_SMBUS:
443 return i2cdev_ioctl_smbus(client, arg);
444
445 case I2C_RETRIES:
446 client->adapter->retries = arg;
447 break;
448 case I2C_TIMEOUT:
449
450
451
452 client->adapter->timeout = msecs_to_jiffies(arg * 10);
453 break;
454 default:
455
456
457
458
459
460 return -ENOTTY;
461 }
462 return 0;
463}
464
465static int i2cdev_open(struct inode *inode, struct file *file)
466{
467 unsigned int minor = iminor(inode);
468 struct i2c_client *client;
469 struct i2c_adapter *adap;
470 struct i2c_dev *i2c_dev;
471
472 i2c_dev = i2c_dev_get_by_minor(minor);
473 if (!i2c_dev)
474 return -ENODEV;
475
476 adap = i2c_get_adapter(i2c_dev->adap->nr);
477 if (!adap)
478 return -ENODEV;
479
480
481
482
483
484
485
486
487 client = kzalloc(sizeof(*client), GFP_KERNEL);
488 if (!client) {
489 i2c_put_adapter(adap);
490 return -ENOMEM;
491 }
492 snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
493
494 client->adapter = adap;
495 file->private_data = client;
496
497 return 0;
498}
499
500static int i2cdev_release(struct inode *inode, struct file *file)
501{
502 struct i2c_client *client = file->private_data;
503
504 i2c_put_adapter(client->adapter);
505 kfree(client);
506 file->private_data = NULL;
507
508 return 0;
509}
510
511static const struct file_operations i2cdev_fops = {
512 .owner = THIS_MODULE,
513 .llseek = no_llseek,
514 .read = i2cdev_read,
515 .write = i2cdev_write,
516 .unlocked_ioctl = i2cdev_ioctl,
517 .open = i2cdev_open,
518 .release = i2cdev_release,
519};
520
521
522
523static struct class *i2c_dev_class;
524
525static int i2cdev_attach_adapter(struct device *dev, void *dummy)
526{
527 struct i2c_adapter *adap;
528 struct i2c_dev *i2c_dev;
529 int res;
530
531 if (dev->type != &i2c_adapter_type)
532 return 0;
533 adap = to_i2c_adapter(dev);
534
535 i2c_dev = get_free_i2c_dev(adap);
536 if (IS_ERR(i2c_dev))
537 return PTR_ERR(i2c_dev);
538
539
540 i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
541 MKDEV(I2C_MAJOR, adap->nr), NULL,
542 "i2c-%d", adap->nr);
543 if (IS_ERR(i2c_dev->dev)) {
544 res = PTR_ERR(i2c_dev->dev);
545 goto error;
546 }
547 res = device_create_file(i2c_dev->dev, &dev_attr_name);
548 if (res)
549 goto error_destroy;
550
551 pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
552 adap->name, adap->nr);
553 return 0;
554error_destroy:
555 device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
556error:
557 return_i2c_dev(i2c_dev);
558 return res;
559}
560
561static int i2cdev_detach_adapter(struct device *dev, void *dummy)
562{
563 struct i2c_adapter *adap;
564 struct i2c_dev *i2c_dev;
565
566 if (dev->type != &i2c_adapter_type)
567 return 0;
568 adap = to_i2c_adapter(dev);
569
570 i2c_dev = i2c_dev_get_by_minor(adap->nr);
571 if (!i2c_dev)
572 return 0;
573
574 device_remove_file(i2c_dev->dev, &dev_attr_name);
575 return_i2c_dev(i2c_dev);
576 device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
577
578 pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
579 return 0;
580}
581
582int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action,
583 void *data)
584{
585 struct device *dev = data;
586
587 switch (action) {
588 case BUS_NOTIFY_ADD_DEVICE:
589 return i2cdev_attach_adapter(dev, NULL);
590 case BUS_NOTIFY_DEL_DEVICE:
591 return i2cdev_detach_adapter(dev, NULL);
592 }
593
594 return 0;
595}
596
597static struct notifier_block i2cdev_notifier = {
598 .notifier_call = i2cdev_notifier_call,
599};
600
601
602
603
604
605
606
607static int __init i2c_dev_init(void)
608{
609 int res;
610
611 printk(KERN_INFO "i2c /dev entries driver\n");
612
613 res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops);
614 if (res)
615 goto out;
616
617 i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
618 if (IS_ERR(i2c_dev_class)) {
619 res = PTR_ERR(i2c_dev_class);
620 goto out_unreg_chrdev;
621 }
622
623
624 res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
625 if (res)
626 goto out_unreg_class;
627
628
629 i2c_for_each_dev(NULL, i2cdev_attach_adapter);
630
631 return 0;
632
633out_unreg_class:
634 class_destroy(i2c_dev_class);
635out_unreg_chrdev:
636 unregister_chrdev(I2C_MAJOR, "i2c");
637out:
638 printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
639 return res;
640}
641
642static void __exit i2c_dev_exit(void)
643{
644 bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier);
645 i2c_for_each_dev(NULL, i2cdev_detach_adapter);
646 class_destroy(i2c_dev_class);
647 unregister_chrdev(I2C_MAJOR, "i2c");
648}
649
650MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
651 "Simon G. Vogl <simon@tk.uni-linz.ac.at>");
652MODULE_DESCRIPTION("I2C /dev entries driver");
653MODULE_LICENSE("GPL");
654
655module_init(i2c_dev_init);
656module_exit(i2c_dev_exit);
657