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1da177e4 LT |
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 | ||
1da177e4 LT |
29 | #include <linux/kernel.h> |
30 | #include <linux/module.h> | |
31 | #include <linux/fs.h> | |
32 | #include <linux/slab.h> | |
33 | #include <linux/smp_lock.h> | |
1da177e4 LT |
34 | #include <linux/init.h> |
35 | #include <linux/i2c.h> | |
36 | #include <linux/i2c-dev.h> | |
37 | #include <asm/uaccess.h> | |
38 | ||
39 | static struct i2c_client i2cdev_client_template; | |
40 | ||
41 | struct i2c_dev { | |
1da177e4 | 42 | struct i2c_adapter *adap; |
79472132 | 43 | struct class_device *class_dev; |
1da177e4 | 44 | }; |
1da177e4 LT |
45 | |
46 | #define I2C_MINORS 256 | |
47 | static struct i2c_dev *i2c_dev_array[I2C_MINORS]; | |
48 | static DEFINE_SPINLOCK(i2c_dev_array_lock); | |
49 | ||
50 | static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) | |
51 | { | |
52 | struct i2c_dev *i2c_dev; | |
53 | ||
54 | spin_lock(&i2c_dev_array_lock); | |
55 | i2c_dev = i2c_dev_array[index]; | |
56 | spin_unlock(&i2c_dev_array_lock); | |
57 | return i2c_dev; | |
58 | } | |
59 | ||
1da177e4 LT |
60 | static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) |
61 | { | |
62 | struct i2c_dev *i2c_dev; | |
63 | ||
5263ebb5 | 64 | i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); |
1da177e4 LT |
65 | if (!i2c_dev) |
66 | return ERR_PTR(-ENOMEM); | |
1da177e4 LT |
67 | |
68 | spin_lock(&i2c_dev_array_lock); | |
69 | if (i2c_dev_array[adap->nr]) { | |
70 | spin_unlock(&i2c_dev_array_lock); | |
71 | dev_err(&adap->dev, "i2c-dev already has a device assigned to this adapter\n"); | |
72 | goto error; | |
73 | } | |
9455e4c9 | 74 | i2c_dev->adap = adap; |
1da177e4 LT |
75 | i2c_dev_array[adap->nr] = i2c_dev; |
76 | spin_unlock(&i2c_dev_array_lock); | |
77 | return i2c_dev; | |
78 | error: | |
79 | kfree(i2c_dev); | |
80 | return ERR_PTR(-ENODEV); | |
81 | } | |
82 | ||
83 | static void return_i2c_dev(struct i2c_dev *i2c_dev) | |
84 | { | |
85 | spin_lock(&i2c_dev_array_lock); | |
9455e4c9 | 86 | i2c_dev_array[i2c_dev->adap->nr] = NULL; |
1da177e4 LT |
87 | spin_unlock(&i2c_dev_array_lock); |
88 | } | |
89 | ||
90 | static ssize_t show_adapter_name(struct class_device *class_dev, char *buf) | |
91 | { | |
79472132 GKH |
92 | struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(class_dev->devt)); |
93 | ||
94 | if (!i2c_dev) | |
95 | return -ENODEV; | |
1da177e4 LT |
96 | return sprintf(buf, "%s\n", i2c_dev->adap->name); |
97 | } | |
98 | static CLASS_DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL); | |
99 | ||
100 | static ssize_t i2cdev_read (struct file *file, char __user *buf, size_t count, | |
101 | loff_t *offset) | |
102 | { | |
103 | char *tmp; | |
104 | int ret; | |
105 | ||
106 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
107 | ||
108 | if (count > 8192) | |
109 | count = 8192; | |
110 | ||
111 | tmp = kmalloc(count,GFP_KERNEL); | |
112 | if (tmp==NULL) | |
113 | return -ENOMEM; | |
114 | ||
115 | pr_debug("i2c-dev: i2c-%d reading %zd bytes.\n", | |
116 | iminor(file->f_dentry->d_inode), count); | |
117 | ||
118 | ret = i2c_master_recv(client,tmp,count); | |
119 | if (ret >= 0) | |
120 | ret = copy_to_user(buf,tmp,count)?-EFAULT:ret; | |
121 | kfree(tmp); | |
122 | return ret; | |
123 | } | |
124 | ||
125 | static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t count, | |
126 | loff_t *offset) | |
127 | { | |
128 | int ret; | |
129 | char *tmp; | |
130 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
131 | ||
132 | if (count > 8192) | |
133 | count = 8192; | |
134 | ||
135 | tmp = kmalloc(count,GFP_KERNEL); | |
136 | if (tmp==NULL) | |
137 | return -ENOMEM; | |
138 | if (copy_from_user(tmp,buf,count)) { | |
139 | kfree(tmp); | |
140 | return -EFAULT; | |
141 | } | |
142 | ||
143 | pr_debug("i2c-dev: i2c-%d writing %zd bytes.\n", | |
144 | iminor(file->f_dentry->d_inode), count); | |
145 | ||
146 | ret = i2c_master_send(client,tmp,count); | |
147 | kfree(tmp); | |
148 | return ret; | |
149 | } | |
150 | ||
151 | static int i2cdev_ioctl(struct inode *inode, struct file *file, | |
152 | unsigned int cmd, unsigned long arg) | |
153 | { | |
154 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
155 | struct i2c_rdwr_ioctl_data rdwr_arg; | |
156 | struct i2c_smbus_ioctl_data data_arg; | |
157 | union i2c_smbus_data temp; | |
158 | struct i2c_msg *rdwr_pa; | |
159 | u8 __user **data_ptrs; | |
160 | int i,datasize,res; | |
161 | unsigned long funcs; | |
162 | ||
e8aafcb2 JD |
163 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
164 | cmd, arg); | |
1da177e4 LT |
165 | |
166 | switch ( cmd ) { | |
167 | case I2C_SLAVE: | |
168 | case I2C_SLAVE_FORCE: | |
169 | if ((arg > 0x3ff) || | |
170 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) | |
171 | return -EINVAL; | |
172 | if ((cmd == I2C_SLAVE) && i2c_check_addr(client->adapter,arg)) | |
173 | return -EBUSY; | |
174 | client->addr = arg; | |
175 | return 0; | |
176 | case I2C_TENBIT: | |
177 | if (arg) | |
178 | client->flags |= I2C_M_TEN; | |
179 | else | |
180 | client->flags &= ~I2C_M_TEN; | |
181 | return 0; | |
182 | case I2C_PEC: | |
183 | if (arg) | |
184 | client->flags |= I2C_CLIENT_PEC; | |
185 | else | |
186 | client->flags &= ~I2C_CLIENT_PEC; | |
187 | return 0; | |
188 | case I2C_FUNCS: | |
189 | funcs = i2c_get_functionality(client->adapter); | |
190 | return (copy_to_user((unsigned long __user *)arg, &funcs, | |
191 | sizeof(unsigned long)))?-EFAULT:0; | |
192 | ||
193 | case I2C_RDWR: | |
194 | if (copy_from_user(&rdwr_arg, | |
195 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
196 | sizeof(rdwr_arg))) | |
197 | return -EFAULT; | |
198 | ||
d68a861d | 199 | /* Put an arbitrary limit on the number of messages that can |
1da177e4 LT |
200 | * be sent at once */ |
201 | if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS) | |
202 | return -EINVAL; | |
203 | ||
204 | rdwr_pa = (struct i2c_msg *) | |
205 | kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), | |
206 | GFP_KERNEL); | |
207 | ||
208 | if (rdwr_pa == NULL) return -ENOMEM; | |
209 | ||
210 | if (copy_from_user(rdwr_pa, rdwr_arg.msgs, | |
211 | rdwr_arg.nmsgs * sizeof(struct i2c_msg))) { | |
212 | kfree(rdwr_pa); | |
213 | return -EFAULT; | |
214 | } | |
215 | ||
216 | data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL); | |
217 | if (data_ptrs == NULL) { | |
218 | kfree(rdwr_pa); | |
219 | return -ENOMEM; | |
220 | } | |
221 | ||
222 | res = 0; | |
223 | for( i=0; i<rdwr_arg.nmsgs; i++ ) { | |
224 | /* Limit the size of the message to a sane amount */ | |
225 | if (rdwr_pa[i].len > 8192) { | |
226 | res = -EINVAL; | |
227 | break; | |
228 | } | |
229 | data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; | |
230 | rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL); | |
231 | if(rdwr_pa[i].buf == NULL) { | |
232 | res = -ENOMEM; | |
233 | break; | |
234 | } | |
235 | if(copy_from_user(rdwr_pa[i].buf, | |
236 | data_ptrs[i], | |
237 | rdwr_pa[i].len)) { | |
238 | ++i; /* Needs to be kfreed too */ | |
239 | res = -EFAULT; | |
240 | break; | |
241 | } | |
242 | } | |
243 | if (res < 0) { | |
244 | int j; | |
245 | for (j = 0; j < i; ++j) | |
246 | kfree(rdwr_pa[j].buf); | |
247 | kfree(data_ptrs); | |
248 | kfree(rdwr_pa); | |
249 | return res; | |
250 | } | |
251 | ||
252 | res = i2c_transfer(client->adapter, | |
253 | rdwr_pa, | |
254 | rdwr_arg.nmsgs); | |
255 | while(i-- > 0) { | |
256 | if( res>=0 && (rdwr_pa[i].flags & I2C_M_RD)) { | |
257 | if(copy_to_user( | |
258 | data_ptrs[i], | |
259 | rdwr_pa[i].buf, | |
260 | rdwr_pa[i].len)) { | |
261 | res = -EFAULT; | |
262 | } | |
263 | } | |
264 | kfree(rdwr_pa[i].buf); | |
265 | } | |
266 | kfree(data_ptrs); | |
267 | kfree(rdwr_pa); | |
268 | return res; | |
269 | ||
270 | case I2C_SMBUS: | |
271 | if (copy_from_user(&data_arg, | |
272 | (struct i2c_smbus_ioctl_data __user *) arg, | |
273 | sizeof(struct i2c_smbus_ioctl_data))) | |
274 | return -EFAULT; | |
275 | if ((data_arg.size != I2C_SMBUS_BYTE) && | |
276 | (data_arg.size != I2C_SMBUS_QUICK) && | |
277 | (data_arg.size != I2C_SMBUS_BYTE_DATA) && | |
278 | (data_arg.size != I2C_SMBUS_WORD_DATA) && | |
279 | (data_arg.size != I2C_SMBUS_PROC_CALL) && | |
280 | (data_arg.size != I2C_SMBUS_BLOCK_DATA) && | |
281 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) && | |
282 | (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
283 | dev_dbg(&client->adapter->dev, | |
284 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
285 | data_arg.size); | |
286 | return -EINVAL; | |
287 | } | |
288 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, | |
289 | so the check is valid if size==I2C_SMBUS_QUICK too. */ | |
290 | if ((data_arg.read_write != I2C_SMBUS_READ) && | |
291 | (data_arg.read_write != I2C_SMBUS_WRITE)) { | |
292 | dev_dbg(&client->adapter->dev, | |
293 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", | |
294 | data_arg.read_write); | |
295 | return -EINVAL; | |
296 | } | |
297 | ||
298 | /* Note that command values are always valid! */ | |
299 | ||
300 | if ((data_arg.size == I2C_SMBUS_QUICK) || | |
301 | ((data_arg.size == I2C_SMBUS_BYTE) && | |
302 | (data_arg.read_write == I2C_SMBUS_WRITE))) | |
303 | /* These are special: we do not use data */ | |
304 | return i2c_smbus_xfer(client->adapter, client->addr, | |
305 | client->flags, | |
306 | data_arg.read_write, | |
307 | data_arg.command, | |
308 | data_arg.size, NULL); | |
309 | ||
310 | if (data_arg.data == NULL) { | |
311 | dev_dbg(&client->adapter->dev, | |
312 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
313 | return -EINVAL; | |
314 | } | |
315 | ||
316 | if ((data_arg.size == I2C_SMBUS_BYTE_DATA) || | |
317 | (data_arg.size == I2C_SMBUS_BYTE)) | |
318 | datasize = sizeof(data_arg.data->byte); | |
319 | else if ((data_arg.size == I2C_SMBUS_WORD_DATA) || | |
320 | (data_arg.size == I2C_SMBUS_PROC_CALL)) | |
321 | datasize = sizeof(data_arg.data->word); | |
322 | else /* size == smbus block, i2c block, or block proc. call */ | |
323 | datasize = sizeof(data_arg.data->block); | |
324 | ||
325 | if ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
326 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
327 | (data_arg.read_write == I2C_SMBUS_WRITE)) { | |
328 | if (copy_from_user(&temp, data_arg.data, datasize)) | |
329 | return -EFAULT; | |
330 | } | |
331 | res = i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
332 | data_arg.read_write, | |
333 | data_arg.command,data_arg.size,&temp); | |
334 | if (! res && ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
335 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
336 | (data_arg.read_write == I2C_SMBUS_READ))) { | |
337 | if (copy_to_user(data_arg.data, &temp, datasize)) | |
338 | return -EFAULT; | |
339 | } | |
340 | return res; | |
341 | ||
342 | default: | |
343 | return i2c_control(client,cmd,arg); | |
344 | } | |
345 | return 0; | |
346 | } | |
347 | ||
348 | static int i2cdev_open(struct inode *inode, struct file *file) | |
349 | { | |
350 | unsigned int minor = iminor(inode); | |
351 | struct i2c_client *client; | |
352 | struct i2c_adapter *adap; | |
353 | struct i2c_dev *i2c_dev; | |
354 | ||
355 | i2c_dev = i2c_dev_get_by_minor(minor); | |
356 | if (!i2c_dev) | |
357 | return -ENODEV; | |
358 | ||
359 | adap = i2c_get_adapter(i2c_dev->adap->nr); | |
360 | if (!adap) | |
361 | return -ENODEV; | |
362 | ||
363 | client = kmalloc(sizeof(*client), GFP_KERNEL); | |
364 | if (!client) { | |
365 | i2c_put_adapter(adap); | |
366 | return -ENOMEM; | |
367 | } | |
368 | memcpy(client, &i2cdev_client_template, sizeof(*client)); | |
369 | ||
370 | /* registered with adapter, passed as client to user */ | |
371 | client->adapter = adap; | |
372 | file->private_data = client; | |
373 | ||
374 | return 0; | |
375 | } | |
376 | ||
377 | static int i2cdev_release(struct inode *inode, struct file *file) | |
378 | { | |
379 | struct i2c_client *client = file->private_data; | |
380 | ||
381 | i2c_put_adapter(client->adapter); | |
382 | kfree(client); | |
383 | file->private_data = NULL; | |
384 | ||
385 | return 0; | |
386 | } | |
387 | ||
388 | static struct file_operations i2cdev_fops = { | |
389 | .owner = THIS_MODULE, | |
390 | .llseek = no_llseek, | |
391 | .read = i2cdev_read, | |
392 | .write = i2cdev_write, | |
393 | .ioctl = i2cdev_ioctl, | |
394 | .open = i2cdev_open, | |
395 | .release = i2cdev_release, | |
396 | }; | |
397 | ||
79472132 | 398 | static struct class *i2c_dev_class; |
1da177e4 LT |
399 | |
400 | static int i2cdev_attach_adapter(struct i2c_adapter *adap) | |
401 | { | |
402 | struct i2c_dev *i2c_dev; | |
1da177e4 LT |
403 | |
404 | i2c_dev = get_free_i2c_dev(adap); | |
405 | if (IS_ERR(i2c_dev)) | |
406 | return PTR_ERR(i2c_dev); | |
407 | ||
b6d7b3d1 | 408 | pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", |
9455e4c9 | 409 | adap->name, adap->nr); |
1da177e4 LT |
410 | |
411 | /* register this i2c device with the driver core */ | |
79472132 | 412 | i2c_dev->class_dev = class_device_create(i2c_dev_class, NULL, |
9455e4c9 JD |
413 | MKDEV(I2C_MAJOR, adap->nr), |
414 | &adap->dev, "i2c-%d", | |
415 | adap->nr); | |
79472132 | 416 | if (!i2c_dev->class_dev) |
1da177e4 | 417 | goto error; |
79472132 | 418 | class_device_create_file(i2c_dev->class_dev, &class_device_attr_name); |
1da177e4 LT |
419 | return 0; |
420 | error: | |
421 | return_i2c_dev(i2c_dev); | |
422 | kfree(i2c_dev); | |
79472132 | 423 | return -ENODEV; |
1da177e4 LT |
424 | } |
425 | ||
426 | static int i2cdev_detach_adapter(struct i2c_adapter *adap) | |
427 | { | |
428 | struct i2c_dev *i2c_dev; | |
429 | ||
9455e4c9 | 430 | i2c_dev = i2c_dev_get_by_minor(adap->nr); |
1da177e4 LT |
431 | if (!i2c_dev) |
432 | return -ENODEV; | |
433 | ||
1da177e4 | 434 | return_i2c_dev(i2c_dev); |
9455e4c9 | 435 | class_device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 LT |
436 | kfree(i2c_dev); |
437 | ||
b6d7b3d1 | 438 | pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
439 | return 0; |
440 | } | |
441 | ||
442 | static int i2cdev_detach_client(struct i2c_client *client) | |
443 | { | |
444 | return 0; | |
445 | } | |
446 | ||
1da177e4 | 447 | static struct i2c_driver i2cdev_driver = { |
35d8b2e6 | 448 | .driver = { |
35d8b2e6 LR |
449 | .name = "dev_driver", |
450 | }, | |
1da177e4 | 451 | .id = I2C_DRIVERID_I2CDEV, |
1da177e4 LT |
452 | .attach_adapter = i2cdev_attach_adapter, |
453 | .detach_adapter = i2cdev_detach_adapter, | |
454 | .detach_client = i2cdev_detach_client, | |
1da177e4 LT |
455 | }; |
456 | ||
457 | static struct i2c_client i2cdev_client_template = { | |
458 | .name = "I2C /dev entry", | |
459 | .addr = -1, | |
460 | .driver = &i2cdev_driver, | |
461 | }; | |
462 | ||
463 | static int __init i2c_dev_init(void) | |
464 | { | |
465 | int res; | |
466 | ||
467 | printk(KERN_INFO "i2c /dev entries driver\n"); | |
468 | ||
469 | res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops); | |
470 | if (res) | |
471 | goto out; | |
472 | ||
79472132 GKH |
473 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
474 | if (IS_ERR(i2c_dev_class)) | |
1da177e4 LT |
475 | goto out_unreg_chrdev; |
476 | ||
477 | res = i2c_add_driver(&i2cdev_driver); | |
478 | if (res) | |
479 | goto out_unreg_class; | |
480 | ||
1da177e4 LT |
481 | return 0; |
482 | ||
483 | out_unreg_class: | |
79472132 | 484 | class_destroy(i2c_dev_class); |
1da177e4 LT |
485 | out_unreg_chrdev: |
486 | unregister_chrdev(I2C_MAJOR, "i2c"); | |
487 | out: | |
488 | printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); | |
489 | return res; | |
490 | } | |
491 | ||
492 | static void __exit i2c_dev_exit(void) | |
493 | { | |
494 | i2c_del_driver(&i2cdev_driver); | |
79472132 | 495 | class_destroy(i2c_dev_class); |
1da177e4 LT |
496 | unregister_chrdev(I2C_MAJOR,"i2c"); |
497 | } | |
498 | ||
499 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
500 | "Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
501 | MODULE_DESCRIPTION("I2C /dev entries driver"); | |
502 | MODULE_LICENSE("GPL"); | |
503 | ||
504 | module_init(i2c_dev_init); | |
505 | module_exit(i2c_dev_exit); |