i2c: Fix the i2c_smbus_read_i2c_block_data() prototype
[linux-2.6.git] / drivers / i2c / i2c-dev.c
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     You should have received a copy of the GNU General Public License
19     along with this program; if not, write to the Free Software
20     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 */
22
23 /* Note that this is a complete rewrite of Simon Vogl's i2c-dev module.
24    But I have used so much of his original code and ideas that it seems
25    only fair to recognize him as co-author -- Frodo */
26
27 /* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */
28
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 <asm/uaccess.h>
38
39 static struct i2c_driver i2cdev_driver;
40
41 struct i2c_dev {
42         struct list_head list;
43         struct i2c_adapter *adap;
44         struct device *dev;
45 };
46
47 #define I2C_MINORS      256
48 static LIST_HEAD(i2c_dev_list);
49 static DEFINE_SPINLOCK(i2c_dev_list_lock);
50
51 static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
52 {
53         struct i2c_dev *i2c_dev;
54
55         spin_lock(&i2c_dev_list_lock);
56         list_for_each_entry(i2c_dev, &i2c_dev_list, list) {
57                 if (i2c_dev->adap->nr == index)
58                         goto found;
59         }
60         i2c_dev = NULL;
61 found:
62         spin_unlock(&i2c_dev_list_lock);
63         return i2c_dev;
64 }
65
66 static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
67 {
68         struct i2c_dev *i2c_dev;
69
70         if (adap->nr >= I2C_MINORS) {
71                 printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
72                        adap->nr);
73                 return ERR_PTR(-ENODEV);
74         }
75
76         i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
77         if (!i2c_dev)
78                 return ERR_PTR(-ENOMEM);
79         i2c_dev->adap = adap;
80
81         spin_lock(&i2c_dev_list_lock);
82         list_add_tail(&i2c_dev->list, &i2c_dev_list);
83         spin_unlock(&i2c_dev_list_lock);
84         return i2c_dev;
85 }
86
87 static void return_i2c_dev(struct i2c_dev *i2c_dev)
88 {
89         spin_lock(&i2c_dev_list_lock);
90         list_del(&i2c_dev->list);
91         spin_unlock(&i2c_dev_list_lock);
92         kfree(i2c_dev);
93 }
94
95 static ssize_t show_adapter_name(struct device *dev,
96                                  struct device_attribute *attr, char *buf)
97 {
98         struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt));
99
100         if (!i2c_dev)
101                 return -ENODEV;
102         return sprintf(buf, "%s\n", i2c_dev->adap->name);
103 }
104 static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
105
106 static ssize_t i2cdev_read (struct file *file, char __user *buf, size_t count,
107                             loff_t *offset)
108 {
109         char *tmp;
110         int ret;
111
112         struct i2c_client *client = (struct i2c_client *)file->private_data;
113
114         if (count > 8192)
115                 count = 8192;
116
117         tmp = kmalloc(count,GFP_KERNEL);
118         if (tmp==NULL)
119                 return -ENOMEM;
120
121         pr_debug("i2c-dev: i2c-%d reading %zd bytes.\n",
122                 iminor(file->f_path.dentry->d_inode), count);
123
124         ret = i2c_master_recv(client,tmp,count);
125         if (ret >= 0)
126                 ret = copy_to_user(buf,tmp,count)?-EFAULT:ret;
127         kfree(tmp);
128         return ret;
129 }
130
131 static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t count,
132                              loff_t *offset)
133 {
134         int ret;
135         char *tmp;
136         struct i2c_client *client = (struct i2c_client *)file->private_data;
137
138         if (count > 8192)
139                 count = 8192;
140
141         tmp = kmalloc(count,GFP_KERNEL);
142         if (tmp==NULL)
143                 return -ENOMEM;
144         if (copy_from_user(tmp,buf,count)) {
145                 kfree(tmp);
146                 return -EFAULT;
147         }
148
149         pr_debug("i2c-dev: i2c-%d writing %zd bytes.\n",
150                 iminor(file->f_path.dentry->d_inode), count);
151
152         ret = i2c_master_send(client,tmp,count);
153         kfree(tmp);
154         return ret;
155 }
156
157 static int i2cdev_ioctl(struct inode *inode, struct file *file,
158                 unsigned int cmd, unsigned long arg)
159 {
160         struct i2c_client *client = (struct i2c_client *)file->private_data;
161         struct i2c_rdwr_ioctl_data rdwr_arg;
162         struct i2c_smbus_ioctl_data data_arg;
163         union i2c_smbus_data temp;
164         struct i2c_msg *rdwr_pa;
165         u8 __user **data_ptrs;
166         int i,datasize,res;
167         unsigned long funcs;
168
169         dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
170                 cmd, arg);
171
172         switch ( cmd ) {
173         case I2C_SLAVE:
174         case I2C_SLAVE_FORCE:
175                 if ((arg > 0x3ff) ||
176                     (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
177                         return -EINVAL;
178                 if ((cmd == I2C_SLAVE) && i2c_check_addr(client->adapter,arg))
179                         return -EBUSY;
180                 client->addr = arg;
181                 return 0;
182         case I2C_TENBIT:
183                 if (arg)
184                         client->flags |= I2C_M_TEN;
185                 else
186                         client->flags &= ~I2C_M_TEN;
187                 return 0;
188         case I2C_PEC:
189                 if (arg)
190                         client->flags |= I2C_CLIENT_PEC;
191                 else
192                         client->flags &= ~I2C_CLIENT_PEC;
193                 return 0;
194         case I2C_FUNCS:
195                 funcs = i2c_get_functionality(client->adapter);
196                 return put_user(funcs, (unsigned long __user *)arg);
197
198         case I2C_RDWR:
199                 if (copy_from_user(&rdwr_arg,
200                                    (struct i2c_rdwr_ioctl_data __user *)arg,
201                                    sizeof(rdwr_arg)))
202                         return -EFAULT;
203
204                 /* Put an arbitrary limit on the number of messages that can
205                  * be sent at once */
206                 if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
207                         return -EINVAL;
208
209                 rdwr_pa = (struct i2c_msg *)
210                         kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
211                         GFP_KERNEL);
212
213                 if (rdwr_pa == NULL) return -ENOMEM;
214
215                 if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
216                                    rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
217                         kfree(rdwr_pa);
218                         return -EFAULT;
219                 }
220
221                 data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
222                 if (data_ptrs == NULL) {
223                         kfree(rdwr_pa);
224                         return -ENOMEM;
225                 }
226
227                 res = 0;
228                 for( i=0; i<rdwr_arg.nmsgs; i++ ) {
229                         /* Limit the size of the message to a sane amount */
230                         if (rdwr_pa[i].len > 8192) {
231                                 res = -EINVAL;
232                                 break;
233                         }
234                         data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
235                         rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
236                         if(rdwr_pa[i].buf == NULL) {
237                                 res = -ENOMEM;
238                                 break;
239                         }
240                         if(copy_from_user(rdwr_pa[i].buf,
241                                 data_ptrs[i],
242                                 rdwr_pa[i].len)) {
243                                         ++i; /* Needs to be kfreed too */
244                                         res = -EFAULT;
245                                 break;
246                         }
247                 }
248                 if (res < 0) {
249                         int j;
250                         for (j = 0; j < i; ++j)
251                                 kfree(rdwr_pa[j].buf);
252                         kfree(data_ptrs);
253                         kfree(rdwr_pa);
254                         return res;
255                 }
256
257                 res = i2c_transfer(client->adapter,
258                         rdwr_pa,
259                         rdwr_arg.nmsgs);
260                 while(i-- > 0) {
261                         if( res>=0 && (rdwr_pa[i].flags & I2C_M_RD)) {
262                                 if(copy_to_user(
263                                         data_ptrs[i],
264                                         rdwr_pa[i].buf,
265                                         rdwr_pa[i].len)) {
266                                         res = -EFAULT;
267                                 }
268                         }
269                         kfree(rdwr_pa[i].buf);
270                 }
271                 kfree(data_ptrs);
272                 kfree(rdwr_pa);
273                 return res;
274
275         case I2C_SMBUS:
276                 if (copy_from_user(&data_arg,
277                                    (struct i2c_smbus_ioctl_data __user *) arg,
278                                    sizeof(struct i2c_smbus_ioctl_data)))
279                         return -EFAULT;
280                 if ((data_arg.size != I2C_SMBUS_BYTE) &&
281                     (data_arg.size != I2C_SMBUS_QUICK) &&
282                     (data_arg.size != I2C_SMBUS_BYTE_DATA) &&
283                     (data_arg.size != I2C_SMBUS_WORD_DATA) &&
284                     (data_arg.size != I2C_SMBUS_PROC_CALL) &&
285                     (data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
286                     (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
287                     (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
288                     (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
289                         dev_dbg(&client->adapter->dev,
290                                 "size out of range (%x) in ioctl I2C_SMBUS.\n",
291                                 data_arg.size);
292                         return -EINVAL;
293                 }
294                 /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
295                    so the check is valid if size==I2C_SMBUS_QUICK too. */
296                 if ((data_arg.read_write != I2C_SMBUS_READ) &&
297                     (data_arg.read_write != I2C_SMBUS_WRITE)) {
298                         dev_dbg(&client->adapter->dev,
299                                 "read_write out of range (%x) in ioctl I2C_SMBUS.\n",
300                                 data_arg.read_write);
301                         return -EINVAL;
302                 }
303
304                 /* Note that command values are always valid! */
305
306                 if ((data_arg.size == I2C_SMBUS_QUICK) ||
307                     ((data_arg.size == I2C_SMBUS_BYTE) &&
308                     (data_arg.read_write == I2C_SMBUS_WRITE)))
309                         /* These are special: we do not use data */
310                         return i2c_smbus_xfer(client->adapter, client->addr,
311                                               client->flags,
312                                               data_arg.read_write,
313                                               data_arg.command,
314                                               data_arg.size, NULL);
315
316                 if (data_arg.data == NULL) {
317                         dev_dbg(&client->adapter->dev,
318                                 "data is NULL pointer in ioctl I2C_SMBUS.\n");
319                         return -EINVAL;
320                 }
321
322                 if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
323                     (data_arg.size == I2C_SMBUS_BYTE))
324                         datasize = sizeof(data_arg.data->byte);
325                 else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
326                          (data_arg.size == I2C_SMBUS_PROC_CALL))
327                         datasize = sizeof(data_arg.data->word);
328                 else /* size == smbus block, i2c block, or block proc. call */
329                         datasize = sizeof(data_arg.data->block);
330
331                 if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
332                     (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
333                     (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
334                     (data_arg.read_write == I2C_SMBUS_WRITE)) {
335                         if (copy_from_user(&temp, data_arg.data, datasize))
336                                 return -EFAULT;
337                 }
338                 if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
339                         /* Convert old I2C block commands to the new
340                            convention. This preserves binary compatibility. */
341                         data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
342                         if (data_arg.read_write == I2C_SMBUS_READ)
343                                 temp.block[0] = I2C_SMBUS_BLOCK_MAX;
344                 }
345                 res = i2c_smbus_xfer(client->adapter,client->addr,client->flags,
346                       data_arg.read_write,
347                       data_arg.command,data_arg.size,&temp);
348                 if (! res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
349                               (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
350                               (data_arg.read_write == I2C_SMBUS_READ))) {
351                         if (copy_to_user(data_arg.data, &temp, datasize))
352                                 return -EFAULT;
353                 }
354                 return res;
355
356         default:
357                 return i2c_control(client,cmd,arg);
358         }
359         return 0;
360 }
361
362 static int i2cdev_open(struct inode *inode, struct file *file)
363 {
364         unsigned int minor = iminor(inode);
365         struct i2c_client *client;
366         struct i2c_adapter *adap;
367         struct i2c_dev *i2c_dev;
368
369         i2c_dev = i2c_dev_get_by_minor(minor);
370         if (!i2c_dev)
371                 return -ENODEV;
372
373         adap = i2c_get_adapter(i2c_dev->adap->nr);
374         if (!adap)
375                 return -ENODEV;
376
377         client = kzalloc(sizeof(*client), GFP_KERNEL);
378         if (!client) {
379                 i2c_put_adapter(adap);
380                 return -ENOMEM;
381         }
382         snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
383         client->driver = &i2cdev_driver;
384
385         /* registered with adapter, passed as client to user */
386         client->adapter = adap;
387         file->private_data = client;
388
389         return 0;
390 }
391
392 static int i2cdev_release(struct inode *inode, struct file *file)
393 {
394         struct i2c_client *client = file->private_data;
395
396         i2c_put_adapter(client->adapter);
397         kfree(client);
398         file->private_data = NULL;
399
400         return 0;
401 }
402
403 static const struct file_operations i2cdev_fops = {
404         .owner          = THIS_MODULE,
405         .llseek         = no_llseek,
406         .read           = i2cdev_read,
407         .write          = i2cdev_write,
408         .ioctl          = i2cdev_ioctl,
409         .open           = i2cdev_open,
410         .release        = i2cdev_release,
411 };
412
413 static struct class *i2c_dev_class;
414
415 static int i2cdev_attach_adapter(struct i2c_adapter *adap)
416 {
417         struct i2c_dev *i2c_dev;
418         int res;
419
420         i2c_dev = get_free_i2c_dev(adap);
421         if (IS_ERR(i2c_dev))
422                 return PTR_ERR(i2c_dev);
423
424         /* register this i2c device with the driver core */
425         i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
426                                      MKDEV(I2C_MAJOR, adap->nr),
427                                      "i2c-%d", adap->nr);
428         if (IS_ERR(i2c_dev->dev)) {
429                 res = PTR_ERR(i2c_dev->dev);
430                 goto error;
431         }
432         res = device_create_file(i2c_dev->dev, &dev_attr_name);
433         if (res)
434                 goto error_destroy;
435
436         pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
437                  adap->name, adap->nr);
438         return 0;
439 error_destroy:
440         device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
441 error:
442         return_i2c_dev(i2c_dev);
443         return res;
444 }
445
446 static int i2cdev_detach_adapter(struct i2c_adapter *adap)
447 {
448         struct i2c_dev *i2c_dev;
449
450         i2c_dev = i2c_dev_get_by_minor(adap->nr);
451         if (!i2c_dev) /* attach_adapter must have failed */
452                 return 0;
453
454         device_remove_file(i2c_dev->dev, &dev_attr_name);
455         return_i2c_dev(i2c_dev);
456         device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
457
458         pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
459         return 0;
460 }
461
462 static int i2cdev_detach_client(struct i2c_client *client)
463 {
464         return 0;
465 }
466
467 static struct i2c_driver i2cdev_driver = {
468         .driver = {
469                 .name   = "dev_driver",
470         },
471         .id             = I2C_DRIVERID_I2CDEV,
472         .attach_adapter = i2cdev_attach_adapter,
473         .detach_adapter = i2cdev_detach_adapter,
474         .detach_client  = i2cdev_detach_client,
475 };
476
477 static int __init i2c_dev_init(void)
478 {
479         int res;
480
481         printk(KERN_INFO "i2c /dev entries driver\n");
482
483         res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops);
484         if (res)
485                 goto out;
486
487         i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
488         if (IS_ERR(i2c_dev_class))
489                 goto out_unreg_chrdev;
490
491         res = i2c_add_driver(&i2cdev_driver);
492         if (res)
493                 goto out_unreg_class;
494
495         return 0;
496
497 out_unreg_class:
498         class_destroy(i2c_dev_class);
499 out_unreg_chrdev:
500         unregister_chrdev(I2C_MAJOR, "i2c");
501 out:
502         printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
503         return res;
504 }
505
506 static void __exit i2c_dev_exit(void)
507 {
508         i2c_del_driver(&i2cdev_driver);
509         class_destroy(i2c_dev_class);
510         unregister_chrdev(I2C_MAJOR,"i2c");
511 }
512
513 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
514                 "Simon G. Vogl <simon@tk.uni-linz.ac.at>");
515 MODULE_DESCRIPTION("I2C /dev entries driver");
516 MODULE_LICENSE("GPL");
517
518 module_init(i2c_dev_init);
519 module_exit(i2c_dev_exit);