]>
Commit | Line | Data |
---|---|---|
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> | |
d052d1be | 37 | #include <linux/platform_device.h> |
1da177e4 LT |
38 | #include <asm/uaccess.h> |
39 | ||
40 | static struct i2c_client i2cdev_client_template; | |
41 | ||
42 | struct i2c_dev { | |
43 | int minor; | |
44 | struct i2c_adapter *adap; | |
79472132 | 45 | struct class_device *class_dev; |
1da177e4 LT |
46 | }; |
47 | #define to_i2c_dev(d) container_of(d, struct i2c_dev, class_dev) | |
48 | ||
49 | #define I2C_MINORS 256 | |
50 | static struct i2c_dev *i2c_dev_array[I2C_MINORS]; | |
51 | static DEFINE_SPINLOCK(i2c_dev_array_lock); | |
52 | ||
53 | static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) | |
54 | { | |
55 | struct i2c_dev *i2c_dev; | |
56 | ||
57 | spin_lock(&i2c_dev_array_lock); | |
58 | i2c_dev = i2c_dev_array[index]; | |
59 | spin_unlock(&i2c_dev_array_lock); | |
60 | return i2c_dev; | |
61 | } | |
62 | ||
63 | static struct i2c_dev *i2c_dev_get_by_adapter(struct i2c_adapter *adap) | |
64 | { | |
65 | struct i2c_dev *i2c_dev = NULL; | |
66 | ||
67 | spin_lock(&i2c_dev_array_lock); | |
68 | if ((i2c_dev_array[adap->nr]) && | |
69 | (i2c_dev_array[adap->nr]->adap == adap)) | |
70 | i2c_dev = i2c_dev_array[adap->nr]; | |
71 | spin_unlock(&i2c_dev_array_lock); | |
72 | return i2c_dev; | |
73 | } | |
74 | ||
75 | static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) | |
76 | { | |
77 | struct i2c_dev *i2c_dev; | |
78 | ||
5263ebb5 | 79 | i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); |
1da177e4 LT |
80 | if (!i2c_dev) |
81 | return ERR_PTR(-ENOMEM); | |
1da177e4 LT |
82 | |
83 | spin_lock(&i2c_dev_array_lock); | |
84 | if (i2c_dev_array[adap->nr]) { | |
85 | spin_unlock(&i2c_dev_array_lock); | |
86 | dev_err(&adap->dev, "i2c-dev already has a device assigned to this adapter\n"); | |
87 | goto error; | |
88 | } | |
89 | i2c_dev->minor = adap->nr; | |
90 | i2c_dev_array[adap->nr] = i2c_dev; | |
91 | spin_unlock(&i2c_dev_array_lock); | |
92 | return i2c_dev; | |
93 | error: | |
94 | kfree(i2c_dev); | |
95 | return ERR_PTR(-ENODEV); | |
96 | } | |
97 | ||
98 | static void return_i2c_dev(struct i2c_dev *i2c_dev) | |
99 | { | |
100 | spin_lock(&i2c_dev_array_lock); | |
101 | i2c_dev_array[i2c_dev->minor] = NULL; | |
102 | spin_unlock(&i2c_dev_array_lock); | |
103 | } | |
104 | ||
105 | static ssize_t show_adapter_name(struct class_device *class_dev, char *buf) | |
106 | { | |
79472132 GKH |
107 | struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(class_dev->devt)); |
108 | ||
109 | if (!i2c_dev) | |
110 | return -ENODEV; | |
1da177e4 LT |
111 | return sprintf(buf, "%s\n", i2c_dev->adap->name); |
112 | } | |
113 | static CLASS_DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL); | |
114 | ||
115 | static ssize_t i2cdev_read (struct file *file, char __user *buf, size_t count, | |
116 | loff_t *offset) | |
117 | { | |
118 | char *tmp; | |
119 | int ret; | |
120 | ||
121 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
122 | ||
123 | if (count > 8192) | |
124 | count = 8192; | |
125 | ||
126 | tmp = kmalloc(count,GFP_KERNEL); | |
127 | if (tmp==NULL) | |
128 | return -ENOMEM; | |
129 | ||
130 | pr_debug("i2c-dev: i2c-%d reading %zd bytes.\n", | |
131 | iminor(file->f_dentry->d_inode), count); | |
132 | ||
133 | ret = i2c_master_recv(client,tmp,count); | |
134 | if (ret >= 0) | |
135 | ret = copy_to_user(buf,tmp,count)?-EFAULT:ret; | |
136 | kfree(tmp); | |
137 | return ret; | |
138 | } | |
139 | ||
140 | static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t count, | |
141 | loff_t *offset) | |
142 | { | |
143 | int ret; | |
144 | char *tmp; | |
145 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
146 | ||
147 | if (count > 8192) | |
148 | count = 8192; | |
149 | ||
150 | tmp = kmalloc(count,GFP_KERNEL); | |
151 | if (tmp==NULL) | |
152 | return -ENOMEM; | |
153 | if (copy_from_user(tmp,buf,count)) { | |
154 | kfree(tmp); | |
155 | return -EFAULT; | |
156 | } | |
157 | ||
158 | pr_debug("i2c-dev: i2c-%d writing %zd bytes.\n", | |
159 | iminor(file->f_dentry->d_inode), count); | |
160 | ||
161 | ret = i2c_master_send(client,tmp,count); | |
162 | kfree(tmp); | |
163 | return ret; | |
164 | } | |
165 | ||
166 | static int i2cdev_ioctl(struct inode *inode, struct file *file, | |
167 | unsigned int cmd, unsigned long arg) | |
168 | { | |
169 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
170 | struct i2c_rdwr_ioctl_data rdwr_arg; | |
171 | struct i2c_smbus_ioctl_data data_arg; | |
172 | union i2c_smbus_data temp; | |
173 | struct i2c_msg *rdwr_pa; | |
174 | u8 __user **data_ptrs; | |
175 | int i,datasize,res; | |
176 | unsigned long funcs; | |
177 | ||
e8aafcb2 JD |
178 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
179 | cmd, arg); | |
1da177e4 LT |
180 | |
181 | switch ( cmd ) { | |
182 | case I2C_SLAVE: | |
183 | case I2C_SLAVE_FORCE: | |
184 | if ((arg > 0x3ff) || | |
185 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) | |
186 | return -EINVAL; | |
187 | if ((cmd == I2C_SLAVE) && i2c_check_addr(client->adapter,arg)) | |
188 | return -EBUSY; | |
189 | client->addr = arg; | |
190 | return 0; | |
191 | case I2C_TENBIT: | |
192 | if (arg) | |
193 | client->flags |= I2C_M_TEN; | |
194 | else | |
195 | client->flags &= ~I2C_M_TEN; | |
196 | return 0; | |
197 | case I2C_PEC: | |
198 | if (arg) | |
199 | client->flags |= I2C_CLIENT_PEC; | |
200 | else | |
201 | client->flags &= ~I2C_CLIENT_PEC; | |
202 | return 0; | |
203 | case I2C_FUNCS: | |
204 | funcs = i2c_get_functionality(client->adapter); | |
205 | return (copy_to_user((unsigned long __user *)arg, &funcs, | |
206 | sizeof(unsigned long)))?-EFAULT:0; | |
207 | ||
208 | case I2C_RDWR: | |
209 | if (copy_from_user(&rdwr_arg, | |
210 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
211 | sizeof(rdwr_arg))) | |
212 | return -EFAULT; | |
213 | ||
d68a861d | 214 | /* Put an arbitrary limit on the number of messages that can |
1da177e4 LT |
215 | * be sent at once */ |
216 | if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS) | |
217 | return -EINVAL; | |
218 | ||
219 | rdwr_pa = (struct i2c_msg *) | |
220 | kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), | |
221 | GFP_KERNEL); | |
222 | ||
223 | if (rdwr_pa == NULL) return -ENOMEM; | |
224 | ||
225 | if (copy_from_user(rdwr_pa, rdwr_arg.msgs, | |
226 | rdwr_arg.nmsgs * sizeof(struct i2c_msg))) { | |
227 | kfree(rdwr_pa); | |
228 | return -EFAULT; | |
229 | } | |
230 | ||
231 | data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL); | |
232 | if (data_ptrs == NULL) { | |
233 | kfree(rdwr_pa); | |
234 | return -ENOMEM; | |
235 | } | |
236 | ||
237 | res = 0; | |
238 | for( i=0; i<rdwr_arg.nmsgs; i++ ) { | |
239 | /* Limit the size of the message to a sane amount */ | |
240 | if (rdwr_pa[i].len > 8192) { | |
241 | res = -EINVAL; | |
242 | break; | |
243 | } | |
244 | data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; | |
245 | rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL); | |
246 | if(rdwr_pa[i].buf == NULL) { | |
247 | res = -ENOMEM; | |
248 | break; | |
249 | } | |
250 | if(copy_from_user(rdwr_pa[i].buf, | |
251 | data_ptrs[i], | |
252 | rdwr_pa[i].len)) { | |
253 | ++i; /* Needs to be kfreed too */ | |
254 | res = -EFAULT; | |
255 | break; | |
256 | } | |
257 | } | |
258 | if (res < 0) { | |
259 | int j; | |
260 | for (j = 0; j < i; ++j) | |
261 | kfree(rdwr_pa[j].buf); | |
262 | kfree(data_ptrs); | |
263 | kfree(rdwr_pa); | |
264 | return res; | |
265 | } | |
266 | ||
267 | res = i2c_transfer(client->adapter, | |
268 | rdwr_pa, | |
269 | rdwr_arg.nmsgs); | |
270 | while(i-- > 0) { | |
271 | if( res>=0 && (rdwr_pa[i].flags & I2C_M_RD)) { | |
272 | if(copy_to_user( | |
273 | data_ptrs[i], | |
274 | rdwr_pa[i].buf, | |
275 | rdwr_pa[i].len)) { | |
276 | res = -EFAULT; | |
277 | } | |
278 | } | |
279 | kfree(rdwr_pa[i].buf); | |
280 | } | |
281 | kfree(data_ptrs); | |
282 | kfree(rdwr_pa); | |
283 | return res; | |
284 | ||
285 | case I2C_SMBUS: | |
286 | if (copy_from_user(&data_arg, | |
287 | (struct i2c_smbus_ioctl_data __user *) arg, | |
288 | sizeof(struct i2c_smbus_ioctl_data))) | |
289 | return -EFAULT; | |
290 | if ((data_arg.size != I2C_SMBUS_BYTE) && | |
291 | (data_arg.size != I2C_SMBUS_QUICK) && | |
292 | (data_arg.size != I2C_SMBUS_BYTE_DATA) && | |
293 | (data_arg.size != I2C_SMBUS_WORD_DATA) && | |
294 | (data_arg.size != I2C_SMBUS_PROC_CALL) && | |
295 | (data_arg.size != I2C_SMBUS_BLOCK_DATA) && | |
296 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) && | |
297 | (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
298 | dev_dbg(&client->adapter->dev, | |
299 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
300 | data_arg.size); | |
301 | return -EINVAL; | |
302 | } | |
303 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, | |
304 | so the check is valid if size==I2C_SMBUS_QUICK too. */ | |
305 | if ((data_arg.read_write != I2C_SMBUS_READ) && | |
306 | (data_arg.read_write != I2C_SMBUS_WRITE)) { | |
307 | dev_dbg(&client->adapter->dev, | |
308 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", | |
309 | data_arg.read_write); | |
310 | return -EINVAL; | |
311 | } | |
312 | ||
313 | /* Note that command values are always valid! */ | |
314 | ||
315 | if ((data_arg.size == I2C_SMBUS_QUICK) || | |
316 | ((data_arg.size == I2C_SMBUS_BYTE) && | |
317 | (data_arg.read_write == I2C_SMBUS_WRITE))) | |
318 | /* These are special: we do not use data */ | |
319 | return i2c_smbus_xfer(client->adapter, client->addr, | |
320 | client->flags, | |
321 | data_arg.read_write, | |
322 | data_arg.command, | |
323 | data_arg.size, NULL); | |
324 | ||
325 | if (data_arg.data == NULL) { | |
326 | dev_dbg(&client->adapter->dev, | |
327 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
328 | return -EINVAL; | |
329 | } | |
330 | ||
331 | if ((data_arg.size == I2C_SMBUS_BYTE_DATA) || | |
332 | (data_arg.size == I2C_SMBUS_BYTE)) | |
333 | datasize = sizeof(data_arg.data->byte); | |
334 | else if ((data_arg.size == I2C_SMBUS_WORD_DATA) || | |
335 | (data_arg.size == I2C_SMBUS_PROC_CALL)) | |
336 | datasize = sizeof(data_arg.data->word); | |
337 | else /* size == smbus block, i2c block, or block proc. call */ | |
338 | datasize = sizeof(data_arg.data->block); | |
339 | ||
340 | if ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
341 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
342 | (data_arg.read_write == I2C_SMBUS_WRITE)) { | |
343 | if (copy_from_user(&temp, data_arg.data, datasize)) | |
344 | return -EFAULT; | |
345 | } | |
346 | res = i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
347 | data_arg.read_write, | |
348 | data_arg.command,data_arg.size,&temp); | |
349 | if (! res && ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
350 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
351 | (data_arg.read_write == I2C_SMBUS_READ))) { | |
352 | if (copy_to_user(data_arg.data, &temp, datasize)) | |
353 | return -EFAULT; | |
354 | } | |
355 | return res; | |
356 | ||
357 | default: | |
358 | return i2c_control(client,cmd,arg); | |
359 | } | |
360 | return 0; | |
361 | } | |
362 | ||
363 | static int i2cdev_open(struct inode *inode, struct file *file) | |
364 | { | |
365 | unsigned int minor = iminor(inode); | |
366 | struct i2c_client *client; | |
367 | struct i2c_adapter *adap; | |
368 | struct i2c_dev *i2c_dev; | |
369 | ||
370 | i2c_dev = i2c_dev_get_by_minor(minor); | |
371 | if (!i2c_dev) | |
372 | return -ENODEV; | |
373 | ||
374 | adap = i2c_get_adapter(i2c_dev->adap->nr); | |
375 | if (!adap) | |
376 | return -ENODEV; | |
377 | ||
378 | client = kmalloc(sizeof(*client), GFP_KERNEL); | |
379 | if (!client) { | |
380 | i2c_put_adapter(adap); | |
381 | return -ENOMEM; | |
382 | } | |
383 | memcpy(client, &i2cdev_client_template, sizeof(*client)); | |
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 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 | ||
79472132 | 413 | static struct class *i2c_dev_class; |
1da177e4 LT |
414 | |
415 | static int i2cdev_attach_adapter(struct i2c_adapter *adap) | |
416 | { | |
417 | struct i2c_dev *i2c_dev; | |
79472132 | 418 | struct device *dev; |
1da177e4 LT |
419 | |
420 | i2c_dev = get_free_i2c_dev(adap); | |
421 | if (IS_ERR(i2c_dev)) | |
422 | return PTR_ERR(i2c_dev); | |
423 | ||
b6d7b3d1 JD |
424 | pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", |
425 | adap->name, i2c_dev->minor); | |
1da177e4 LT |
426 | |
427 | /* register this i2c device with the driver core */ | |
428 | i2c_dev->adap = adap; | |
4941b395 | 429 | dev = &adap->dev; |
79472132 GKH |
430 | i2c_dev->class_dev = class_device_create(i2c_dev_class, NULL, |
431 | MKDEV(I2C_MAJOR, i2c_dev->minor), | |
432 | dev, "i2c-%d", i2c_dev->minor); | |
433 | if (!i2c_dev->class_dev) | |
1da177e4 | 434 | goto error; |
79472132 | 435 | class_device_create_file(i2c_dev->class_dev, &class_device_attr_name); |
1da177e4 LT |
436 | return 0; |
437 | error: | |
438 | return_i2c_dev(i2c_dev); | |
439 | kfree(i2c_dev); | |
79472132 | 440 | return -ENODEV; |
1da177e4 LT |
441 | } |
442 | ||
443 | static int i2cdev_detach_adapter(struct i2c_adapter *adap) | |
444 | { | |
445 | struct i2c_dev *i2c_dev; | |
446 | ||
447 | i2c_dev = i2c_dev_get_by_adapter(adap); | |
448 | if (!i2c_dev) | |
449 | return -ENODEV; | |
450 | ||
1da177e4 | 451 | return_i2c_dev(i2c_dev); |
79472132 | 452 | class_device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, i2c_dev->minor)); |
1da177e4 LT |
453 | kfree(i2c_dev); |
454 | ||
b6d7b3d1 | 455 | pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
456 | return 0; |
457 | } | |
458 | ||
459 | static int i2cdev_detach_client(struct i2c_client *client) | |
460 | { | |
461 | return 0; | |
462 | } | |
463 | ||
1da177e4 | 464 | static struct i2c_driver i2cdev_driver = { |
35d8b2e6 | 465 | .driver = { |
35d8b2e6 LR |
466 | .name = "dev_driver", |
467 | }, | |
1da177e4 | 468 | .id = I2C_DRIVERID_I2CDEV, |
1da177e4 LT |
469 | .attach_adapter = i2cdev_attach_adapter, |
470 | .detach_adapter = i2cdev_detach_adapter, | |
471 | .detach_client = i2cdev_detach_client, | |
1da177e4 LT |
472 | }; |
473 | ||
474 | static struct i2c_client i2cdev_client_template = { | |
475 | .name = "I2C /dev entry", | |
476 | .addr = -1, | |
477 | .driver = &i2cdev_driver, | |
478 | }; | |
479 | ||
480 | static int __init i2c_dev_init(void) | |
481 | { | |
482 | int res; | |
483 | ||
484 | printk(KERN_INFO "i2c /dev entries driver\n"); | |
485 | ||
486 | res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops); | |
487 | if (res) | |
488 | goto out; | |
489 | ||
79472132 GKH |
490 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
491 | if (IS_ERR(i2c_dev_class)) | |
1da177e4 LT |
492 | goto out_unreg_chrdev; |
493 | ||
494 | res = i2c_add_driver(&i2cdev_driver); | |
495 | if (res) | |
496 | goto out_unreg_class; | |
497 | ||
1da177e4 LT |
498 | return 0; |
499 | ||
500 | out_unreg_class: | |
79472132 | 501 | class_destroy(i2c_dev_class); |
1da177e4 LT |
502 | out_unreg_chrdev: |
503 | unregister_chrdev(I2C_MAJOR, "i2c"); | |
504 | out: | |
505 | printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); | |
506 | return res; | |
507 | } | |
508 | ||
509 | static void __exit i2c_dev_exit(void) | |
510 | { | |
511 | i2c_del_driver(&i2cdev_driver); | |
79472132 | 512 | class_destroy(i2c_dev_class); |
1da177e4 LT |
513 | unregister_chrdev(I2C_MAJOR,"i2c"); |
514 | } | |
515 | ||
516 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
517 | "Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
518 | MODULE_DESCRIPTION("I2C /dev entries driver"); | |
519 | MODULE_LICENSE("GPL"); | |
520 | ||
521 | module_init(i2c_dev_init); | |
522 | module_exit(i2c_dev_exit); |