blob: 86c4d0149e825a1c560bc58008faee5390b8b8be [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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/* The devfs code is contributed by Philipp Matthias Hahn
30 <pmhahn@titan.lahn.de> */
31
32#include <linux/config.h>
33#include <linux/kernel.h>
34#include <linux/module.h>
35#include <linux/fs.h>
36#include <linux/slab.h>
37#include <linux/smp_lock.h>
38#include <linux/devfs_fs_kernel.h>
39#include <linux/init.h>
40#include <linux/i2c.h>
41#include <linux/i2c-dev.h>
42#include <asm/uaccess.h>
43
44static struct i2c_client i2cdev_client_template;
45
46struct i2c_dev {
47 int minor;
48 struct i2c_adapter *adap;
49 struct class_device class_dev;
50 struct completion released; /* FIXME, we need a class_device_unregister() */
51};
52#define to_i2c_dev(d) container_of(d, struct i2c_dev, class_dev)
53
54#define I2C_MINORS 256
55static struct i2c_dev *i2c_dev_array[I2C_MINORS];
56static DEFINE_SPINLOCK(i2c_dev_array_lock);
57
58static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
59{
60 struct i2c_dev *i2c_dev;
61
62 spin_lock(&i2c_dev_array_lock);
63 i2c_dev = i2c_dev_array[index];
64 spin_unlock(&i2c_dev_array_lock);
65 return i2c_dev;
66}
67
68static struct i2c_dev *i2c_dev_get_by_adapter(struct i2c_adapter *adap)
69{
70 struct i2c_dev *i2c_dev = NULL;
71
72 spin_lock(&i2c_dev_array_lock);
73 if ((i2c_dev_array[adap->nr]) &&
74 (i2c_dev_array[adap->nr]->adap == adap))
75 i2c_dev = i2c_dev_array[adap->nr];
76 spin_unlock(&i2c_dev_array_lock);
77 return i2c_dev;
78}
79
80static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
81{
82 struct i2c_dev *i2c_dev;
83
84 i2c_dev = kmalloc(sizeof(*i2c_dev), GFP_KERNEL);
85 if (!i2c_dev)
86 return ERR_PTR(-ENOMEM);
87 memset(i2c_dev, 0x00, sizeof(*i2c_dev));
88
89 spin_lock(&i2c_dev_array_lock);
90 if (i2c_dev_array[adap->nr]) {
91 spin_unlock(&i2c_dev_array_lock);
92 dev_err(&adap->dev, "i2c-dev already has a device assigned to this adapter\n");
93 goto error;
94 }
95 i2c_dev->minor = adap->nr;
96 i2c_dev_array[adap->nr] = i2c_dev;
97 spin_unlock(&i2c_dev_array_lock);
98 return i2c_dev;
99error:
100 kfree(i2c_dev);
101 return ERR_PTR(-ENODEV);
102}
103
104static void return_i2c_dev(struct i2c_dev *i2c_dev)
105{
106 spin_lock(&i2c_dev_array_lock);
107 i2c_dev_array[i2c_dev->minor] = NULL;
108 spin_unlock(&i2c_dev_array_lock);
109}
110
111static ssize_t show_adapter_name(struct class_device *class_dev, char *buf)
112{
113 struct i2c_dev *i2c_dev = to_i2c_dev(class_dev);
114 return sprintf(buf, "%s\n", i2c_dev->adap->name);
115}
116static CLASS_DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
117
118static ssize_t i2cdev_read (struct file *file, char __user *buf, size_t count,
119 loff_t *offset)
120{
121 char *tmp;
122 int ret;
123
124 struct i2c_client *client = (struct i2c_client *)file->private_data;
125
126 if (count > 8192)
127 count = 8192;
128
129 tmp = kmalloc(count,GFP_KERNEL);
130 if (tmp==NULL)
131 return -ENOMEM;
132
133 pr_debug("i2c-dev: i2c-%d reading %zd bytes.\n",
134 iminor(file->f_dentry->d_inode), count);
135
136 ret = i2c_master_recv(client,tmp,count);
137 if (ret >= 0)
138 ret = copy_to_user(buf,tmp,count)?-EFAULT:ret;
139 kfree(tmp);
140 return ret;
141}
142
143static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t count,
144 loff_t *offset)
145{
146 int ret;
147 char *tmp;
148 struct i2c_client *client = (struct i2c_client *)file->private_data;
149
150 if (count > 8192)
151 count = 8192;
152
153 tmp = kmalloc(count,GFP_KERNEL);
154 if (tmp==NULL)
155 return -ENOMEM;
156 if (copy_from_user(tmp,buf,count)) {
157 kfree(tmp);
158 return -EFAULT;
159 }
160
161 pr_debug("i2c-dev: i2c-%d writing %zd bytes.\n",
162 iminor(file->f_dentry->d_inode), count);
163
164 ret = i2c_master_send(client,tmp,count);
165 kfree(tmp);
166 return ret;
167}
168
169static int i2cdev_ioctl(struct inode *inode, struct file *file,
170 unsigned int cmd, unsigned long arg)
171{
172 struct i2c_client *client = (struct i2c_client *)file->private_data;
173 struct i2c_rdwr_ioctl_data rdwr_arg;
174 struct i2c_smbus_ioctl_data data_arg;
175 union i2c_smbus_data temp;
176 struct i2c_msg *rdwr_pa;
177 u8 __user **data_ptrs;
178 int i,datasize,res;
179 unsigned long funcs;
180
181 dev_dbg(&client->adapter->dev, "i2c-%d ioctl, cmd: 0x%x, arg: %lx.\n",
182 iminor(inode),cmd, arg);
183
184 switch ( cmd ) {
185 case I2C_SLAVE:
186 case I2C_SLAVE_FORCE:
187 if ((arg > 0x3ff) ||
188 (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
189 return -EINVAL;
190 if ((cmd == I2C_SLAVE) && i2c_check_addr(client->adapter,arg))
191 return -EBUSY;
192 client->addr = arg;
193 return 0;
194 case I2C_TENBIT:
195 if (arg)
196 client->flags |= I2C_M_TEN;
197 else
198 client->flags &= ~I2C_M_TEN;
199 return 0;
200 case I2C_PEC:
201 if (arg)
202 client->flags |= I2C_CLIENT_PEC;
203 else
204 client->flags &= ~I2C_CLIENT_PEC;
205 return 0;
206 case I2C_FUNCS:
207 funcs = i2c_get_functionality(client->adapter);
208 return (copy_to_user((unsigned long __user *)arg, &funcs,
209 sizeof(unsigned long)))?-EFAULT:0;
210
211 case I2C_RDWR:
212 if (copy_from_user(&rdwr_arg,
213 (struct i2c_rdwr_ioctl_data __user *)arg,
214 sizeof(rdwr_arg)))
215 return -EFAULT;
216
217 /* Put an arbritrary limit on the number of messages that can
218 * be sent at once */
219 if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
220 return -EINVAL;
221
222 rdwr_pa = (struct i2c_msg *)
223 kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
224 GFP_KERNEL);
225
226 if (rdwr_pa == NULL) return -ENOMEM;
227
228 if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
229 rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
230 kfree(rdwr_pa);
231 return -EFAULT;
232 }
233
234 data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
235 if (data_ptrs == NULL) {
236 kfree(rdwr_pa);
237 return -ENOMEM;
238 }
239
240 res = 0;
241 for( i=0; i<rdwr_arg.nmsgs; i++ ) {
242 /* Limit the size of the message to a sane amount */
243 if (rdwr_pa[i].len > 8192) {
244 res = -EINVAL;
245 break;
246 }
247 data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
248 rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
249 if(rdwr_pa[i].buf == NULL) {
250 res = -ENOMEM;
251 break;
252 }
253 if(copy_from_user(rdwr_pa[i].buf,
254 data_ptrs[i],
255 rdwr_pa[i].len)) {
256 ++i; /* Needs to be kfreed too */
257 res = -EFAULT;
258 break;
259 }
260 }
261 if (res < 0) {
262 int j;
263 for (j = 0; j < i; ++j)
264 kfree(rdwr_pa[j].buf);
265 kfree(data_ptrs);
266 kfree(rdwr_pa);
267 return res;
268 }
269
270 res = i2c_transfer(client->adapter,
271 rdwr_pa,
272 rdwr_arg.nmsgs);
273 while(i-- > 0) {
274 if( res>=0 && (rdwr_pa[i].flags & I2C_M_RD)) {
275 if(copy_to_user(
276 data_ptrs[i],
277 rdwr_pa[i].buf,
278 rdwr_pa[i].len)) {
279 res = -EFAULT;
280 }
281 }
282 kfree(rdwr_pa[i].buf);
283 }
284 kfree(data_ptrs);
285 kfree(rdwr_pa);
286 return res;
287
288 case I2C_SMBUS:
289 if (copy_from_user(&data_arg,
290 (struct i2c_smbus_ioctl_data __user *) arg,
291 sizeof(struct i2c_smbus_ioctl_data)))
292 return -EFAULT;
293 if ((data_arg.size != I2C_SMBUS_BYTE) &&
294 (data_arg.size != I2C_SMBUS_QUICK) &&
295 (data_arg.size != I2C_SMBUS_BYTE_DATA) &&
296 (data_arg.size != I2C_SMBUS_WORD_DATA) &&
297 (data_arg.size != I2C_SMBUS_PROC_CALL) &&
298 (data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
299 (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
300 (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
301 dev_dbg(&client->adapter->dev,
302 "size out of range (%x) in ioctl I2C_SMBUS.\n",
303 data_arg.size);
304 return -EINVAL;
305 }
306 /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
307 so the check is valid if size==I2C_SMBUS_QUICK too. */
308 if ((data_arg.read_write != I2C_SMBUS_READ) &&
309 (data_arg.read_write != I2C_SMBUS_WRITE)) {
310 dev_dbg(&client->adapter->dev,
311 "read_write out of range (%x) in ioctl I2C_SMBUS.\n",
312 data_arg.read_write);
313 return -EINVAL;
314 }
315
316 /* Note that command values are always valid! */
317
318 if ((data_arg.size == I2C_SMBUS_QUICK) ||
319 ((data_arg.size == I2C_SMBUS_BYTE) &&
320 (data_arg.read_write == I2C_SMBUS_WRITE)))
321 /* These are special: we do not use data */
322 return i2c_smbus_xfer(client->adapter, client->addr,
323 client->flags,
324 data_arg.read_write,
325 data_arg.command,
326 data_arg.size, NULL);
327
328 if (data_arg.data == NULL) {
329 dev_dbg(&client->adapter->dev,
330 "data is NULL pointer in ioctl I2C_SMBUS.\n");
331 return -EINVAL;
332 }
333
334 if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
335 (data_arg.size == I2C_SMBUS_BYTE))
336 datasize = sizeof(data_arg.data->byte);
337 else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
338 (data_arg.size == I2C_SMBUS_PROC_CALL))
339 datasize = sizeof(data_arg.data->word);
340 else /* size == smbus block, i2c block, or block proc. call */
341 datasize = sizeof(data_arg.data->block);
342
343 if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
344 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
345 (data_arg.read_write == I2C_SMBUS_WRITE)) {
346 if (copy_from_user(&temp, data_arg.data, datasize))
347 return -EFAULT;
348 }
349 res = i2c_smbus_xfer(client->adapter,client->addr,client->flags,
350 data_arg.read_write,
351 data_arg.command,data_arg.size,&temp);
352 if (! res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
353 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
354 (data_arg.read_write == I2C_SMBUS_READ))) {
355 if (copy_to_user(data_arg.data, &temp, datasize))
356 return -EFAULT;
357 }
358 return res;
359
360 default:
361 return i2c_control(client,cmd,arg);
362 }
363 return 0;
364}
365
366static int i2cdev_open(struct inode *inode, struct file *file)
367{
368 unsigned int minor = iminor(inode);
369 struct i2c_client *client;
370 struct i2c_adapter *adap;
371 struct i2c_dev *i2c_dev;
372
373 i2c_dev = i2c_dev_get_by_minor(minor);
374 if (!i2c_dev)
375 return -ENODEV;
376
377 adap = i2c_get_adapter(i2c_dev->adap->nr);
378 if (!adap)
379 return -ENODEV;
380
381 client = kmalloc(sizeof(*client), GFP_KERNEL);
382 if (!client) {
383 i2c_put_adapter(adap);
384 return -ENOMEM;
385 }
386 memcpy(client, &i2cdev_client_template, sizeof(*client));
387
388 /* registered with adapter, passed as client to user */
389 client->adapter = adap;
390 file->private_data = client;
391
392 return 0;
393}
394
395static int i2cdev_release(struct inode *inode, struct file *file)
396{
397 struct i2c_client *client = file->private_data;
398
399 i2c_put_adapter(client->adapter);
400 kfree(client);
401 file->private_data = NULL;
402
403 return 0;
404}
405
406static struct file_operations i2cdev_fops = {
407 .owner = THIS_MODULE,
408 .llseek = no_llseek,
409 .read = i2cdev_read,
410 .write = i2cdev_write,
411 .ioctl = i2cdev_ioctl,
412 .open = i2cdev_open,
413 .release = i2cdev_release,
414};
415
416static void release_i2c_dev(struct class_device *dev)
417{
418 struct i2c_dev *i2c_dev = to_i2c_dev(dev);
419 complete(&i2c_dev->released);
420}
421
422static struct class i2c_dev_class = {
423 .name = "i2c-dev",
424 .release = &release_i2c_dev,
425};
426
427static int i2cdev_attach_adapter(struct i2c_adapter *adap)
428{
429 struct i2c_dev *i2c_dev;
430 int retval;
431
432 i2c_dev = get_free_i2c_dev(adap);
433 if (IS_ERR(i2c_dev))
434 return PTR_ERR(i2c_dev);
435
436 devfs_mk_cdev(MKDEV(I2C_MAJOR, i2c_dev->minor),
437 S_IFCHR|S_IRUSR|S_IWUSR, "i2c/%d", i2c_dev->minor);
438 dev_dbg(&adap->dev, "Registered as minor %d\n", i2c_dev->minor);
439
440 /* register this i2c device with the driver core */
441 i2c_dev->adap = adap;
442 if (adap->dev.parent == &platform_bus)
443 i2c_dev->class_dev.dev = &adap->dev;
444 else
445 i2c_dev->class_dev.dev = adap->dev.parent;
446 i2c_dev->class_dev.class = &i2c_dev_class;
447 i2c_dev->class_dev.devt = MKDEV(I2C_MAJOR, i2c_dev->minor);
448 snprintf(i2c_dev->class_dev.class_id, BUS_ID_SIZE, "i2c-%d", i2c_dev->minor);
449 retval = class_device_register(&i2c_dev->class_dev);
450 if (retval)
451 goto error;
452 class_device_create_file(&i2c_dev->class_dev, &class_device_attr_name);
453 return 0;
454error:
455 return_i2c_dev(i2c_dev);
456 kfree(i2c_dev);
457 return retval;
458}
459
460static int i2cdev_detach_adapter(struct i2c_adapter *adap)
461{
462 struct i2c_dev *i2c_dev;
463
464 i2c_dev = i2c_dev_get_by_adapter(adap);
465 if (!i2c_dev)
466 return -ENODEV;
467
468 init_completion(&i2c_dev->released);
469 devfs_remove("i2c/%d", i2c_dev->minor);
470 return_i2c_dev(i2c_dev);
471 class_device_unregister(&i2c_dev->class_dev);
472 wait_for_completion(&i2c_dev->released);
473 kfree(i2c_dev);
474
475 dev_dbg(&adap->dev, "Adapter unregistered\n");
476 return 0;
477}
478
479static int i2cdev_detach_client(struct i2c_client *client)
480{
481 return 0;
482}
483
484static int i2cdev_command(struct i2c_client *client, unsigned int cmd,
485 void *arg)
486{
487 return -1;
488}
489
490static struct i2c_driver i2cdev_driver = {
491 .owner = THIS_MODULE,
492 .name = "dev_driver",
493 .id = I2C_DRIVERID_I2CDEV,
494 .flags = I2C_DF_NOTIFY,
495 .attach_adapter = i2cdev_attach_adapter,
496 .detach_adapter = i2cdev_detach_adapter,
497 .detach_client = i2cdev_detach_client,
498 .command = i2cdev_command,
499};
500
501static struct i2c_client i2cdev_client_template = {
502 .name = "I2C /dev entry",
503 .addr = -1,
504 .driver = &i2cdev_driver,
505};
506
507static int __init i2c_dev_init(void)
508{
509 int res;
510
511 printk(KERN_INFO "i2c /dev entries driver\n");
512
513 res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops);
514 if (res)
515 goto out;
516
517 res = class_register(&i2c_dev_class);
518 if (res)
519 goto out_unreg_chrdev;
520
521 res = i2c_add_driver(&i2cdev_driver);
522 if (res)
523 goto out_unreg_class;
524
525 devfs_mk_dir("i2c");
526
527 return 0;
528
529out_unreg_class:
530 class_unregister(&i2c_dev_class);
531out_unreg_chrdev:
532 unregister_chrdev(I2C_MAJOR, "i2c");
533out:
534 printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
535 return res;
536}
537
538static void __exit i2c_dev_exit(void)
539{
540 i2c_del_driver(&i2cdev_driver);
541 class_unregister(&i2c_dev_class);
542 devfs_remove("i2c");
543 unregister_chrdev(I2C_MAJOR,"i2c");
544}
545
546MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
547 "Simon G. Vogl <simon@tk.uni-linz.ac.at>");
548MODULE_DESCRIPTION("I2C /dev entries driver");
549MODULE_LICENSE("GPL");
550
551module_init(i2c_dev_init);
552module_exit(i2c_dev_exit);