Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
438d6c2c | 2 | i2c-dev.c - i2c-bus driver, char device interface |
1da177e4 LT |
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 | |
5694f8a8 JD |
20 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, |
21 | MA 02110-1301 USA. | |
1da177e4 LT |
22 | */ |
23 | ||
24 | /* Note that this is a complete rewrite of Simon Vogl's i2c-dev module. | |
25 | But I have used so much of his original code and ideas that it seems | |
26 | only fair to recognize him as co-author -- Frodo */ | |
27 | ||
28 | /* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */ | |
29 | ||
1da177e4 LT |
30 | #include <linux/kernel.h> |
31 | #include <linux/module.h> | |
9ea3e941 JD |
32 | #include <linux/device.h> |
33 | #include <linux/notifier.h> | |
1da177e4 LT |
34 | #include <linux/fs.h> |
35 | #include <linux/slab.h> | |
1da177e4 | 36 | #include <linux/init.h> |
f3b3aadb | 37 | #include <linux/list.h> |
1da177e4 LT |
38 | #include <linux/i2c.h> |
39 | #include <linux/i2c-dev.h> | |
cd97f39b | 40 | #include <linux/jiffies.h> |
ae5624fc | 41 | #include <linux/uaccess.h> |
1da177e4 | 42 | |
907135aa DB |
43 | /* |
44 | * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a | |
45 | * slave (i2c_client) with which messages will be exchanged. It's coupled | |
46 | * with a character special file which is accessed by user mode drivers. | |
47 | * | |
48 | * The list of i2c_dev structures is parallel to the i2c_adapter lists | |
9ea3e941 | 49 | * maintained by the driver model, and is updated using bus notifications. |
907135aa | 50 | */ |
1da177e4 | 51 | struct i2c_dev { |
f3b3aadb | 52 | struct list_head list; |
1da177e4 | 53 | struct i2c_adapter *adap; |
ac11d060 | 54 | struct device *dev; |
1da177e4 | 55 | }; |
1da177e4 LT |
56 | |
57 | #define I2C_MINORS 256 | |
f3b3aadb JD |
58 | static LIST_HEAD(i2c_dev_list); |
59 | static DEFINE_SPINLOCK(i2c_dev_list_lock); | |
1da177e4 LT |
60 | |
61 | static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) | |
62 | { | |
63 | struct i2c_dev *i2c_dev; | |
64 | ||
f3b3aadb JD |
65 | spin_lock(&i2c_dev_list_lock); |
66 | list_for_each_entry(i2c_dev, &i2c_dev_list, list) { | |
67 | if (i2c_dev->adap->nr == index) | |
68 | goto found; | |
69 | } | |
70 | i2c_dev = NULL; | |
71 | found: | |
72 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 LT |
73 | return i2c_dev; |
74 | } | |
75 | ||
1da177e4 LT |
76 | static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) |
77 | { | |
78 | struct i2c_dev *i2c_dev; | |
79 | ||
f3b3aadb JD |
80 | if (adap->nr >= I2C_MINORS) { |
81 | printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n", | |
82 | adap->nr); | |
83 | return ERR_PTR(-ENODEV); | |
84 | } | |
85 | ||
5263ebb5 | 86 | i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); |
1da177e4 LT |
87 | if (!i2c_dev) |
88 | return ERR_PTR(-ENOMEM); | |
9455e4c9 | 89 | i2c_dev->adap = adap; |
f3b3aadb JD |
90 | |
91 | spin_lock(&i2c_dev_list_lock); | |
92 | list_add_tail(&i2c_dev->list, &i2c_dev_list); | |
93 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 | 94 | return i2c_dev; |
1da177e4 LT |
95 | } |
96 | ||
97 | static void return_i2c_dev(struct i2c_dev *i2c_dev) | |
98 | { | |
f3b3aadb JD |
99 | spin_lock(&i2c_dev_list_lock); |
100 | list_del(&i2c_dev->list); | |
101 | spin_unlock(&i2c_dev_list_lock); | |
07125ab2 | 102 | kfree(i2c_dev); |
1da177e4 LT |
103 | } |
104 | ||
ac11d060 GKH |
105 | static ssize_t show_adapter_name(struct device *dev, |
106 | struct device_attribute *attr, char *buf) | |
1da177e4 | 107 | { |
ac11d060 | 108 | struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt)); |
79472132 GKH |
109 | |
110 | if (!i2c_dev) | |
111 | return -ENODEV; | |
1da177e4 LT |
112 | return sprintf(buf, "%s\n", i2c_dev->adap->name); |
113 | } | |
ac11d060 | 114 | static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL); |
1da177e4 | 115 | |
907135aa DB |
116 | /* ------------------------------------------------------------------------- */ |
117 | ||
118 | /* | |
119 | * After opening an instance of this character special file, a file | |
120 | * descriptor starts out associated only with an i2c_adapter (and bus). | |
121 | * | |
122 | * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg | |
123 | * traffic to any devices on the bus used by that adapter. That's because | |
124 | * the i2c_msg vectors embed all the addressing information they need, and | |
125 | * are submitted directly to an i2c_adapter. However, SMBus-only adapters | |
126 | * don't support that interface. | |
127 | * | |
128 | * To use read()/write() system calls on that file descriptor, or to use | |
129 | * SMBus interfaces (and work with SMBus-only hosts!), you must first issue | |
130 | * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous | |
131 | * (never registered) i2c_client so it holds the addressing information | |
132 | * needed by those system calls and by this SMBus interface. | |
133 | */ | |
134 | ||
ae5624fc FH |
135 | static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count, |
136 | loff_t *offset) | |
1da177e4 LT |
137 | { |
138 | char *tmp; | |
139 | int ret; | |
140 | ||
0be16c30 | 141 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
142 | |
143 | if (count > 8192) | |
144 | count = 8192; | |
145 | ||
ae5624fc FH |
146 | tmp = kmalloc(count, GFP_KERNEL); |
147 | if (tmp == NULL) | |
1da177e4 LT |
148 | return -ENOMEM; |
149 | ||
2ce5b34f | 150 | pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n", |
cba0a128 | 151 | iminor(file->f_path.dentry->d_inode), count); |
1da177e4 | 152 | |
ae5624fc | 153 | ret = i2c_master_recv(client, tmp, count); |
1da177e4 | 154 | if (ret >= 0) |
ae5624fc | 155 | ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret; |
1da177e4 LT |
156 | kfree(tmp); |
157 | return ret; | |
158 | } | |
159 | ||
ae5624fc FH |
160 | static ssize_t i2cdev_write(struct file *file, const char __user *buf, |
161 | size_t count, loff_t *offset) | |
1da177e4 LT |
162 | { |
163 | int ret; | |
164 | char *tmp; | |
0be16c30 | 165 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
166 | |
167 | if (count > 8192) | |
168 | count = 8192; | |
169 | ||
f1c2e33c JL |
170 | tmp = memdup_user(buf, count); |
171 | if (IS_ERR(tmp)) | |
172 | return PTR_ERR(tmp); | |
1da177e4 | 173 | |
2ce5b34f | 174 | pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n", |
cba0a128 | 175 | iminor(file->f_path.dentry->d_inode), count); |
1da177e4 | 176 | |
ae5624fc | 177 | ret = i2c_master_send(client, tmp, count); |
1da177e4 LT |
178 | kfree(tmp); |
179 | return ret; | |
180 | } | |
181 | ||
9b766b81 DB |
182 | static int i2cdev_check(struct device *dev, void *addrp) |
183 | { | |
184 | struct i2c_client *client = i2c_verify_client(dev); | |
185 | ||
186 | if (!client || client->addr != *(unsigned int *)addrp) | |
187 | return 0; | |
188 | ||
189 | return dev->driver ? -EBUSY : 0; | |
190 | } | |
191 | ||
0826374b ML |
192 | /* walk up mux tree */ |
193 | static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
194 | { | |
97cc4d49 | 195 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
196 | int result; |
197 | ||
198 | result = device_for_each_child(&adapter->dev, &addr, i2cdev_check); | |
97cc4d49 JD |
199 | if (!result && parent) |
200 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
201 | |
202 | return result; | |
203 | } | |
204 | ||
205 | /* recurse down mux tree */ | |
206 | static int i2cdev_check_mux_children(struct device *dev, void *addrp) | |
207 | { | |
208 | int result; | |
209 | ||
210 | if (dev->type == &i2c_adapter_type) | |
211 | result = device_for_each_child(dev, addrp, | |
212 | i2cdev_check_mux_children); | |
213 | else | |
214 | result = i2cdev_check(dev, addrp); | |
215 | ||
216 | return result; | |
217 | } | |
218 | ||
bd4217d8 JD |
219 | /* This address checking function differs from the one in i2c-core |
220 | in that it considers an address with a registered device, but no | |
9b766b81 | 221 | driver bound to it, as NOT busy. */ |
bd4217d8 JD |
222 | static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) |
223 | { | |
97cc4d49 | 224 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
225 | int result = 0; |
226 | ||
97cc4d49 JD |
227 | if (parent) |
228 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
229 | |
230 | if (!result) | |
231 | result = device_for_each_child(&adapter->dev, &addr, | |
232 | i2cdev_check_mux_children); | |
233 | ||
234 | return result; | |
bd4217d8 JD |
235 | } |
236 | ||
dba7997a JD |
237 | static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client, |
238 | unsigned long arg) | |
1da177e4 | 239 | { |
1da177e4 | 240 | struct i2c_rdwr_ioctl_data rdwr_arg; |
1da177e4 LT |
241 | struct i2c_msg *rdwr_pa; |
242 | u8 __user **data_ptrs; | |
dba7997a JD |
243 | int i, res; |
244 | ||
245 | if (copy_from_user(&rdwr_arg, | |
246 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
247 | sizeof(rdwr_arg))) | |
248 | return -EFAULT; | |
249 | ||
250 | /* Put an arbitrary limit on the number of messages that can | |
251 | * be sent at once */ | |
252 | if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS) | |
253 | return -EINVAL; | |
254 | ||
a699ed6f TM |
255 | rdwr_pa = memdup_user(rdwr_arg.msgs, |
256 | rdwr_arg.nmsgs * sizeof(struct i2c_msg)); | |
257 | if (IS_ERR(rdwr_pa)) | |
258 | return PTR_ERR(rdwr_pa); | |
dba7997a JD |
259 | |
260 | data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL); | |
261 | if (data_ptrs == NULL) { | |
262 | kfree(rdwr_pa); | |
263 | return -ENOMEM; | |
264 | } | |
265 | ||
266 | res = 0; | |
267 | for (i = 0; i < rdwr_arg.nmsgs; i++) { | |
268 | /* Limit the size of the message to a sane amount; | |
269 | * and don't let length change either. */ | |
270 | if ((rdwr_pa[i].len > 8192) || | |
271 | (rdwr_pa[i].flags & I2C_M_RECV_LEN)) { | |
272 | res = -EINVAL; | |
273 | break; | |
274 | } | |
275 | data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; | |
f1c2e33c JL |
276 | rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len); |
277 | if (IS_ERR(rdwr_pa[i].buf)) { | |
278 | res = PTR_ERR(rdwr_pa[i].buf); | |
dba7997a JD |
279 | break; |
280 | } | |
281 | } | |
282 | if (res < 0) { | |
283 | int j; | |
284 | for (j = 0; j < i; ++j) | |
285 | kfree(rdwr_pa[j].buf); | |
286 | kfree(data_ptrs); | |
287 | kfree(rdwr_pa); | |
288 | return res; | |
289 | } | |
290 | ||
291 | res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs); | |
292 | while (i-- > 0) { | |
293 | if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) { | |
294 | if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf, | |
295 | rdwr_pa[i].len)) | |
296 | res = -EFAULT; | |
297 | } | |
298 | kfree(rdwr_pa[i].buf); | |
299 | } | |
300 | kfree(data_ptrs); | |
301 | kfree(rdwr_pa); | |
302 | return res; | |
303 | } | |
304 | ||
305 | static noinline int i2cdev_ioctl_smbus(struct i2c_client *client, | |
306 | unsigned long arg) | |
307 | { | |
308 | struct i2c_smbus_ioctl_data data_arg; | |
309 | union i2c_smbus_data temp; | |
310 | int datasize, res; | |
311 | ||
312 | if (copy_from_user(&data_arg, | |
313 | (struct i2c_smbus_ioctl_data __user *) arg, | |
314 | sizeof(struct i2c_smbus_ioctl_data))) | |
315 | return -EFAULT; | |
316 | if ((data_arg.size != I2C_SMBUS_BYTE) && | |
317 | (data_arg.size != I2C_SMBUS_QUICK) && | |
318 | (data_arg.size != I2C_SMBUS_BYTE_DATA) && | |
319 | (data_arg.size != I2C_SMBUS_WORD_DATA) && | |
320 | (data_arg.size != I2C_SMBUS_PROC_CALL) && | |
321 | (data_arg.size != I2C_SMBUS_BLOCK_DATA) && | |
322 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) && | |
323 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) && | |
324 | (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
325 | dev_dbg(&client->adapter->dev, | |
326 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
327 | data_arg.size); | |
328 | return -EINVAL; | |
329 | } | |
330 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, | |
331 | so the check is valid if size==I2C_SMBUS_QUICK too. */ | |
332 | if ((data_arg.read_write != I2C_SMBUS_READ) && | |
333 | (data_arg.read_write != I2C_SMBUS_WRITE)) { | |
334 | dev_dbg(&client->adapter->dev, | |
335 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", | |
336 | data_arg.read_write); | |
337 | return -EINVAL; | |
338 | } | |
339 | ||
340 | /* Note that command values are always valid! */ | |
341 | ||
342 | if ((data_arg.size == I2C_SMBUS_QUICK) || | |
343 | ((data_arg.size == I2C_SMBUS_BYTE) && | |
344 | (data_arg.read_write == I2C_SMBUS_WRITE))) | |
345 | /* These are special: we do not use data */ | |
346 | return i2c_smbus_xfer(client->adapter, client->addr, | |
347 | client->flags, data_arg.read_write, | |
348 | data_arg.command, data_arg.size, NULL); | |
349 | ||
350 | if (data_arg.data == NULL) { | |
351 | dev_dbg(&client->adapter->dev, | |
352 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
353 | return -EINVAL; | |
354 | } | |
355 | ||
356 | if ((data_arg.size == I2C_SMBUS_BYTE_DATA) || | |
357 | (data_arg.size == I2C_SMBUS_BYTE)) | |
358 | datasize = sizeof(data_arg.data->byte); | |
359 | else if ((data_arg.size == I2C_SMBUS_WORD_DATA) || | |
360 | (data_arg.size == I2C_SMBUS_PROC_CALL)) | |
361 | datasize = sizeof(data_arg.data->word); | |
362 | else /* size == smbus block, i2c block, or block proc. call */ | |
363 | datasize = sizeof(data_arg.data->block); | |
364 | ||
365 | if ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
366 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
367 | (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) || | |
368 | (data_arg.read_write == I2C_SMBUS_WRITE)) { | |
369 | if (copy_from_user(&temp, data_arg.data, datasize)) | |
370 | return -EFAULT; | |
371 | } | |
372 | if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) { | |
373 | /* Convert old I2C block commands to the new | |
374 | convention. This preserves binary compatibility. */ | |
375 | data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA; | |
376 | if (data_arg.read_write == I2C_SMBUS_READ) | |
377 | temp.block[0] = I2C_SMBUS_BLOCK_MAX; | |
378 | } | |
379 | res = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
380 | data_arg.read_write, data_arg.command, data_arg.size, &temp); | |
381 | if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
382 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
383 | (data_arg.read_write == I2C_SMBUS_READ))) { | |
384 | if (copy_to_user(data_arg.data, &temp, datasize)) | |
385 | return -EFAULT; | |
386 | } | |
387 | return res; | |
388 | } | |
389 | ||
77e38bff | 390 | static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
dba7997a | 391 | { |
0be16c30 | 392 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
393 | unsigned long funcs; |
394 | ||
e8aafcb2 JD |
395 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
396 | cmd, arg); | |
1da177e4 | 397 | |
ae5624fc | 398 | switch (cmd) { |
1da177e4 LT |
399 | case I2C_SLAVE: |
400 | case I2C_SLAVE_FORCE: | |
907135aa DB |
401 | /* NOTE: devices set up to work with "new style" drivers |
402 | * can't use I2C_SLAVE, even when the device node is not | |
403 | * bound to a driver. Only I2C_SLAVE_FORCE will work. | |
404 | * | |
405 | * Setting the PEC flag here won't affect kernel drivers, | |
406 | * which will be using the i2c_client node registered with | |
407 | * the driver model core. Likewise, when that client has | |
408 | * the PEC flag already set, the i2c-dev driver won't see | |
409 | * (or use) this setting. | |
410 | */ | |
438d6c2c | 411 | if ((arg > 0x3ff) || |
1da177e4 LT |
412 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) |
413 | return -EINVAL; | |
bd4217d8 | 414 | if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg)) |
1da177e4 | 415 | return -EBUSY; |
bd4217d8 | 416 | /* REVISIT: address could become busy later */ |
1da177e4 LT |
417 | client->addr = arg; |
418 | return 0; | |
419 | case I2C_TENBIT: | |
420 | if (arg) | |
421 | client->flags |= I2C_M_TEN; | |
422 | else | |
423 | client->flags &= ~I2C_M_TEN; | |
424 | return 0; | |
425 | case I2C_PEC: | |
426 | if (arg) | |
427 | client->flags |= I2C_CLIENT_PEC; | |
428 | else | |
429 | client->flags &= ~I2C_CLIENT_PEC; | |
430 | return 0; | |
431 | case I2C_FUNCS: | |
432 | funcs = i2c_get_functionality(client->adapter); | |
2c003e8e | 433 | return put_user(funcs, (unsigned long __user *)arg); |
1da177e4 LT |
434 | |
435 | case I2C_RDWR: | |
dba7997a | 436 | return i2cdev_ioctl_rdrw(client, arg); |
1da177e4 LT |
437 | |
438 | case I2C_SMBUS: | |
dba7997a | 439 | return i2cdev_ioctl_smbus(client, arg); |
1da177e4 | 440 | |
53be7959 DB |
441 | case I2C_RETRIES: |
442 | client->adapter->retries = arg; | |
443 | break; | |
444 | case I2C_TIMEOUT: | |
cd97f39b JD |
445 | /* For historical reasons, user-space sets the timeout |
446 | * value in units of 10 ms. | |
447 | */ | |
448 | client->adapter->timeout = msecs_to_jiffies(arg * 10); | |
53be7959 | 449 | break; |
1da177e4 | 450 | default: |
53be7959 DB |
451 | /* NOTE: returning a fault code here could cause trouble |
452 | * in buggy userspace code. Some old kernel bugs returned | |
453 | * zero in this case, and userspace code might accidentally | |
454 | * have depended on that bug. | |
455 | */ | |
456 | return -ENOTTY; | |
1da177e4 LT |
457 | } |
458 | return 0; | |
459 | } | |
460 | ||
461 | static int i2cdev_open(struct inode *inode, struct file *file) | |
462 | { | |
463 | unsigned int minor = iminor(inode); | |
464 | struct i2c_client *client; | |
465 | struct i2c_adapter *adap; | |
466 | struct i2c_dev *i2c_dev; | |
467 | ||
468 | i2c_dev = i2c_dev_get_by_minor(minor); | |
9669f541 VS |
469 | if (!i2c_dev) |
470 | return -ENODEV; | |
1da177e4 LT |
471 | |
472 | adap = i2c_get_adapter(i2c_dev->adap->nr); | |
9669f541 VS |
473 | if (!adap) |
474 | return -ENODEV; | |
1da177e4 | 475 | |
907135aa DB |
476 | /* This creates an anonymous i2c_client, which may later be |
477 | * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE. | |
478 | * | |
479 | * This client is ** NEVER REGISTERED ** with the driver model | |
480 | * or I2C core code!! It just holds private copies of addressing | |
481 | * information and maybe a PEC flag. | |
482 | */ | |
22f76e74 | 483 | client = kzalloc(sizeof(*client), GFP_KERNEL); |
1da177e4 LT |
484 | if (!client) { |
485 | i2c_put_adapter(adap); | |
9669f541 | 486 | return -ENOMEM; |
1da177e4 | 487 | } |
22f76e74 | 488 | snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); |
1da177e4 | 489 | |
1da177e4 LT |
490 | client->adapter = adap; |
491 | file->private_data = client; | |
492 | ||
9669f541 | 493 | return 0; |
1da177e4 LT |
494 | } |
495 | ||
496 | static int i2cdev_release(struct inode *inode, struct file *file) | |
497 | { | |
498 | struct i2c_client *client = file->private_data; | |
499 | ||
500 | i2c_put_adapter(client->adapter); | |
501 | kfree(client); | |
502 | file->private_data = NULL; | |
503 | ||
504 | return 0; | |
505 | } | |
506 | ||
2b8693c0 | 507 | static const struct file_operations i2cdev_fops = { |
1da177e4 LT |
508 | .owner = THIS_MODULE, |
509 | .llseek = no_llseek, | |
510 | .read = i2cdev_read, | |
511 | .write = i2cdev_write, | |
77e38bff | 512 | .unlocked_ioctl = i2cdev_ioctl, |
1da177e4 LT |
513 | .open = i2cdev_open, |
514 | .release = i2cdev_release, | |
515 | }; | |
516 | ||
907135aa DB |
517 | /* ------------------------------------------------------------------------- */ |
518 | ||
79472132 | 519 | static struct class *i2c_dev_class; |
1da177e4 | 520 | |
9ea3e941 | 521 | static int i2cdev_attach_adapter(struct device *dev, void *dummy) |
1da177e4 | 522 | { |
9ea3e941 | 523 | struct i2c_adapter *adap; |
1da177e4 | 524 | struct i2c_dev *i2c_dev; |
defcb46e | 525 | int res; |
1da177e4 | 526 | |
9ea3e941 JD |
527 | if (dev->type != &i2c_adapter_type) |
528 | return 0; | |
529 | adap = to_i2c_adapter(dev); | |
530 | ||
1da177e4 LT |
531 | i2c_dev = get_free_i2c_dev(adap); |
532 | if (IS_ERR(i2c_dev)) | |
533 | return PTR_ERR(i2c_dev); | |
534 | ||
1da177e4 | 535 | /* register this i2c device with the driver core */ |
a9b12619 GKH |
536 | i2c_dev->dev = device_create(i2c_dev_class, &adap->dev, |
537 | MKDEV(I2C_MAJOR, adap->nr), NULL, | |
538 | "i2c-%d", adap->nr); | |
3bacb36d AM |
539 | if (IS_ERR(i2c_dev->dev)) { |
540 | res = PTR_ERR(i2c_dev->dev); | |
1da177e4 | 541 | goto error; |
defcb46e | 542 | } |
ac11d060 | 543 | res = device_create_file(i2c_dev->dev, &dev_attr_name); |
defcb46e JD |
544 | if (res) |
545 | goto error_destroy; | |
b32d20dc JD |
546 | |
547 | pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", | |
548 | adap->name, adap->nr); | |
1da177e4 | 549 | return 0; |
defcb46e | 550 | error_destroy: |
ac11d060 | 551 | device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 LT |
552 | error: |
553 | return_i2c_dev(i2c_dev); | |
defcb46e | 554 | return res; |
1da177e4 LT |
555 | } |
556 | ||
9ea3e941 | 557 | static int i2cdev_detach_adapter(struct device *dev, void *dummy) |
1da177e4 | 558 | { |
9ea3e941 | 559 | struct i2c_adapter *adap; |
1da177e4 LT |
560 | struct i2c_dev *i2c_dev; |
561 | ||
9ea3e941 JD |
562 | if (dev->type != &i2c_adapter_type) |
563 | return 0; | |
564 | adap = to_i2c_adapter(dev); | |
565 | ||
9455e4c9 | 566 | i2c_dev = i2c_dev_get_by_minor(adap->nr); |
b32d20dc JD |
567 | if (!i2c_dev) /* attach_adapter must have failed */ |
568 | return 0; | |
1da177e4 | 569 | |
ac11d060 | 570 | device_remove_file(i2c_dev->dev, &dev_attr_name); |
1da177e4 | 571 | return_i2c_dev(i2c_dev); |
ac11d060 | 572 | device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 | 573 | |
b6d7b3d1 | 574 | pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
575 | return 0; |
576 | } | |
577 | ||
eff245c8 | 578 | static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action, |
9ea3e941 JD |
579 | void *data) |
580 | { | |
581 | struct device *dev = data; | |
582 | ||
583 | switch (action) { | |
584 | case BUS_NOTIFY_ADD_DEVICE: | |
585 | return i2cdev_attach_adapter(dev, NULL); | |
586 | case BUS_NOTIFY_DEL_DEVICE: | |
587 | return i2cdev_detach_adapter(dev, NULL); | |
588 | } | |
589 | ||
590 | return 0; | |
591 | } | |
592 | ||
593 | static struct notifier_block i2cdev_notifier = { | |
594 | .notifier_call = i2cdev_notifier_call, | |
1da177e4 LT |
595 | }; |
596 | ||
907135aa DB |
597 | /* ------------------------------------------------------------------------- */ |
598 | ||
599 | /* | |
600 | * module load/unload record keeping | |
601 | */ | |
602 | ||
1da177e4 LT |
603 | static int __init i2c_dev_init(void) |
604 | { | |
605 | int res; | |
606 | ||
607 | printk(KERN_INFO "i2c /dev entries driver\n"); | |
608 | ||
609 | res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops); | |
610 | if (res) | |
611 | goto out; | |
612 | ||
79472132 | 613 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
e74783ec SW |
614 | if (IS_ERR(i2c_dev_class)) { |
615 | res = PTR_ERR(i2c_dev_class); | |
1da177e4 | 616 | goto out_unreg_chrdev; |
e74783ec | 617 | } |
1da177e4 | 618 | |
9ea3e941 JD |
619 | /* Keep track of adapters which will be added or removed later */ |
620 | res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier); | |
1da177e4 LT |
621 | if (res) |
622 | goto out_unreg_class; | |
623 | ||
9ea3e941 JD |
624 | /* Bind to already existing adapters right away */ |
625 | i2c_for_each_dev(NULL, i2cdev_attach_adapter); | |
626 | ||
1da177e4 LT |
627 | return 0; |
628 | ||
629 | out_unreg_class: | |
79472132 | 630 | class_destroy(i2c_dev_class); |
1da177e4 LT |
631 | out_unreg_chrdev: |
632 | unregister_chrdev(I2C_MAJOR, "i2c"); | |
633 | out: | |
634 | printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); | |
635 | return res; | |
636 | } | |
637 | ||
638 | static void __exit i2c_dev_exit(void) | |
639 | { | |
9ea3e941 JD |
640 | bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier); |
641 | i2c_for_each_dev(NULL, i2cdev_detach_adapter); | |
79472132 | 642 | class_destroy(i2c_dev_class); |
ae5624fc | 643 | unregister_chrdev(I2C_MAJOR, "i2c"); |
1da177e4 LT |
644 | } |
645 | ||
646 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
647 | "Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
648 | MODULE_DESCRIPTION("I2C /dev entries driver"); | |
649 | MODULE_LICENSE("GPL"); | |
650 | ||
651 | module_init(i2c_dev_init); | |
652 | module_exit(i2c_dev_exit); |