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 | |
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> | |
9ea3e941 JD |
31 | #include <linux/device.h> |
32 | #include <linux/notifier.h> | |
1da177e4 LT |
33 | #include <linux/fs.h> |
34 | #include <linux/slab.h> | |
1da177e4 | 35 | #include <linux/init.h> |
f3b3aadb | 36 | #include <linux/list.h> |
1da177e4 LT |
37 | #include <linux/i2c.h> |
38 | #include <linux/i2c-dev.h> | |
cd97f39b | 39 | #include <linux/jiffies.h> |
ae5624fc | 40 | #include <linux/uaccess.h> |
1da177e4 | 41 | |
907135aa DB |
42 | /* |
43 | * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a | |
44 | * slave (i2c_client) with which messages will be exchanged. It's coupled | |
45 | * with a character special file which is accessed by user mode drivers. | |
46 | * | |
47 | * The list of i2c_dev structures is parallel to the i2c_adapter lists | |
9ea3e941 | 48 | * maintained by the driver model, and is updated using bus notifications. |
907135aa | 49 | */ |
1da177e4 | 50 | struct i2c_dev { |
f3b3aadb | 51 | struct list_head list; |
1da177e4 | 52 | struct i2c_adapter *adap; |
ac11d060 | 53 | struct device *dev; |
1da177e4 | 54 | }; |
1da177e4 LT |
55 | |
56 | #define I2C_MINORS 256 | |
f3b3aadb JD |
57 | static LIST_HEAD(i2c_dev_list); |
58 | static DEFINE_SPINLOCK(i2c_dev_list_lock); | |
1da177e4 LT |
59 | |
60 | static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) | |
61 | { | |
62 | struct i2c_dev *i2c_dev; | |
63 | ||
f3b3aadb JD |
64 | spin_lock(&i2c_dev_list_lock); |
65 | list_for_each_entry(i2c_dev, &i2c_dev_list, list) { | |
66 | if (i2c_dev->adap->nr == index) | |
67 | goto found; | |
68 | } | |
69 | i2c_dev = NULL; | |
70 | found: | |
71 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 LT |
72 | return i2c_dev; |
73 | } | |
74 | ||
1da177e4 LT |
75 | static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) |
76 | { | |
77 | struct i2c_dev *i2c_dev; | |
78 | ||
f3b3aadb JD |
79 | if (adap->nr >= I2C_MINORS) { |
80 | printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n", | |
81 | adap->nr); | |
82 | return ERR_PTR(-ENODEV); | |
83 | } | |
84 | ||
5263ebb5 | 85 | i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); |
1da177e4 LT |
86 | if (!i2c_dev) |
87 | return ERR_PTR(-ENOMEM); | |
9455e4c9 | 88 | i2c_dev->adap = adap; |
f3b3aadb JD |
89 | |
90 | spin_lock(&i2c_dev_list_lock); | |
91 | list_add_tail(&i2c_dev->list, &i2c_dev_list); | |
92 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 | 93 | return i2c_dev; |
1da177e4 LT |
94 | } |
95 | ||
96 | static void return_i2c_dev(struct i2c_dev *i2c_dev) | |
97 | { | |
f3b3aadb JD |
98 | spin_lock(&i2c_dev_list_lock); |
99 | list_del(&i2c_dev->list); | |
100 | spin_unlock(&i2c_dev_list_lock); | |
07125ab2 | 101 | kfree(i2c_dev); |
1da177e4 LT |
102 | } |
103 | ||
ac11d060 GKH |
104 | static ssize_t show_adapter_name(struct device *dev, |
105 | struct device_attribute *attr, char *buf) | |
1da177e4 | 106 | { |
ac11d060 | 107 | struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt)); |
79472132 GKH |
108 | |
109 | if (!i2c_dev) | |
110 | return -ENODEV; | |
1da177e4 LT |
111 | return sprintf(buf, "%s\n", i2c_dev->adap->name); |
112 | } | |
ac11d060 | 113 | static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL); |
1da177e4 | 114 | |
907135aa DB |
115 | /* ------------------------------------------------------------------------- */ |
116 | ||
117 | /* | |
118 | * After opening an instance of this character special file, a file | |
119 | * descriptor starts out associated only with an i2c_adapter (and bus). | |
120 | * | |
121 | * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg | |
122 | * traffic to any devices on the bus used by that adapter. That's because | |
123 | * the i2c_msg vectors embed all the addressing information they need, and | |
124 | * are submitted directly to an i2c_adapter. However, SMBus-only adapters | |
125 | * don't support that interface. | |
126 | * | |
127 | * To use read()/write() system calls on that file descriptor, or to use | |
128 | * SMBus interfaces (and work with SMBus-only hosts!), you must first issue | |
129 | * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous | |
130 | * (never registered) i2c_client so it holds the addressing information | |
131 | * needed by those system calls and by this SMBus interface. | |
132 | */ | |
133 | ||
ae5624fc FH |
134 | static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count, |
135 | loff_t *offset) | |
1da177e4 LT |
136 | { |
137 | char *tmp; | |
138 | int ret; | |
139 | ||
0be16c30 | 140 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
141 | |
142 | if (count > 8192) | |
143 | count = 8192; | |
144 | ||
ae5624fc FH |
145 | tmp = kmalloc(count, GFP_KERNEL); |
146 | if (tmp == NULL) | |
1da177e4 LT |
147 | return -ENOMEM; |
148 | ||
2ce5b34f | 149 | pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n", |
cba0a128 | 150 | iminor(file->f_path.dentry->d_inode), count); |
1da177e4 | 151 | |
ae5624fc | 152 | ret = i2c_master_recv(client, tmp, count); |
1da177e4 | 153 | if (ret >= 0) |
ae5624fc | 154 | ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret; |
1da177e4 LT |
155 | kfree(tmp); |
156 | return ret; | |
157 | } | |
158 | ||
ae5624fc FH |
159 | static ssize_t i2cdev_write(struct file *file, const char __user *buf, |
160 | size_t count, loff_t *offset) | |
1da177e4 LT |
161 | { |
162 | int ret; | |
163 | char *tmp; | |
0be16c30 | 164 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
165 | |
166 | if (count > 8192) | |
167 | count = 8192; | |
168 | ||
f1c2e33c JL |
169 | tmp = memdup_user(buf, count); |
170 | if (IS_ERR(tmp)) | |
171 | return PTR_ERR(tmp); | |
1da177e4 | 172 | |
2ce5b34f | 173 | pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n", |
cba0a128 | 174 | iminor(file->f_path.dentry->d_inode), count); |
1da177e4 | 175 | |
ae5624fc | 176 | ret = i2c_master_send(client, tmp, count); |
1da177e4 LT |
177 | kfree(tmp); |
178 | return ret; | |
179 | } | |
180 | ||
9b766b81 DB |
181 | static int i2cdev_check(struct device *dev, void *addrp) |
182 | { | |
183 | struct i2c_client *client = i2c_verify_client(dev); | |
184 | ||
185 | if (!client || client->addr != *(unsigned int *)addrp) | |
186 | return 0; | |
187 | ||
188 | return dev->driver ? -EBUSY : 0; | |
189 | } | |
190 | ||
0826374b ML |
191 | /* walk up mux tree */ |
192 | static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
193 | { | |
97cc4d49 | 194 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
195 | int result; |
196 | ||
197 | result = device_for_each_child(&adapter->dev, &addr, i2cdev_check); | |
97cc4d49 JD |
198 | if (!result && parent) |
199 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
200 | |
201 | return result; | |
202 | } | |
203 | ||
204 | /* recurse down mux tree */ | |
205 | static int i2cdev_check_mux_children(struct device *dev, void *addrp) | |
206 | { | |
207 | int result; | |
208 | ||
209 | if (dev->type == &i2c_adapter_type) | |
210 | result = device_for_each_child(dev, addrp, | |
211 | i2cdev_check_mux_children); | |
212 | else | |
213 | result = i2cdev_check(dev, addrp); | |
214 | ||
215 | return result; | |
216 | } | |
217 | ||
bd4217d8 JD |
218 | /* This address checking function differs from the one in i2c-core |
219 | in that it considers an address with a registered device, but no | |
9b766b81 | 220 | driver bound to it, as NOT busy. */ |
bd4217d8 JD |
221 | static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) |
222 | { | |
97cc4d49 | 223 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
224 | int result = 0; |
225 | ||
97cc4d49 JD |
226 | if (parent) |
227 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
228 | |
229 | if (!result) | |
230 | result = device_for_each_child(&adapter->dev, &addr, | |
231 | i2cdev_check_mux_children); | |
232 | ||
233 | return result; | |
bd4217d8 JD |
234 | } |
235 | ||
dba7997a JD |
236 | static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client, |
237 | unsigned long arg) | |
1da177e4 | 238 | { |
1da177e4 | 239 | struct i2c_rdwr_ioctl_data rdwr_arg; |
1da177e4 LT |
240 | struct i2c_msg *rdwr_pa; |
241 | u8 __user **data_ptrs; | |
dba7997a JD |
242 | int i, res; |
243 | ||
244 | if (copy_from_user(&rdwr_arg, | |
245 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
246 | sizeof(rdwr_arg))) | |
247 | return -EFAULT; | |
248 | ||
249 | /* Put an arbitrary limit on the number of messages that can | |
250 | * be sent at once */ | |
251 | if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS) | |
252 | return -EINVAL; | |
253 | ||
35a56c5b | 254 | rdwr_pa = kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), GFP_KERNEL); |
dba7997a JD |
255 | if (!rdwr_pa) |
256 | return -ENOMEM; | |
257 | ||
258 | if (copy_from_user(rdwr_pa, rdwr_arg.msgs, | |
259 | rdwr_arg.nmsgs * sizeof(struct i2c_msg))) { | |
260 | kfree(rdwr_pa); | |
261 | return -EFAULT; | |
262 | } | |
263 | ||
264 | data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL); | |
265 | if (data_ptrs == NULL) { | |
266 | kfree(rdwr_pa); | |
267 | return -ENOMEM; | |
268 | } | |
269 | ||
270 | res = 0; | |
271 | for (i = 0; i < rdwr_arg.nmsgs; i++) { | |
272 | /* Limit the size of the message to a sane amount; | |
273 | * and don't let length change either. */ | |
274 | if ((rdwr_pa[i].len > 8192) || | |
275 | (rdwr_pa[i].flags & I2C_M_RECV_LEN)) { | |
276 | res = -EINVAL; | |
277 | break; | |
278 | } | |
279 | data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; | |
f1c2e33c JL |
280 | rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len); |
281 | if (IS_ERR(rdwr_pa[i].buf)) { | |
282 | res = PTR_ERR(rdwr_pa[i].buf); | |
dba7997a JD |
283 | break; |
284 | } | |
285 | } | |
286 | if (res < 0) { | |
287 | int j; | |
288 | for (j = 0; j < i; ++j) | |
289 | kfree(rdwr_pa[j].buf); | |
290 | kfree(data_ptrs); | |
291 | kfree(rdwr_pa); | |
292 | return res; | |
293 | } | |
294 | ||
295 | res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs); | |
296 | while (i-- > 0) { | |
297 | if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) { | |
298 | if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf, | |
299 | rdwr_pa[i].len)) | |
300 | res = -EFAULT; | |
301 | } | |
302 | kfree(rdwr_pa[i].buf); | |
303 | } | |
304 | kfree(data_ptrs); | |
305 | kfree(rdwr_pa); | |
306 | return res; | |
307 | } | |
308 | ||
309 | static noinline int i2cdev_ioctl_smbus(struct i2c_client *client, | |
310 | unsigned long arg) | |
311 | { | |
312 | struct i2c_smbus_ioctl_data data_arg; | |
313 | union i2c_smbus_data temp; | |
314 | int datasize, res; | |
315 | ||
316 | if (copy_from_user(&data_arg, | |
317 | (struct i2c_smbus_ioctl_data __user *) arg, | |
318 | sizeof(struct i2c_smbus_ioctl_data))) | |
319 | return -EFAULT; | |
320 | if ((data_arg.size != I2C_SMBUS_BYTE) && | |
321 | (data_arg.size != I2C_SMBUS_QUICK) && | |
322 | (data_arg.size != I2C_SMBUS_BYTE_DATA) && | |
323 | (data_arg.size != I2C_SMBUS_WORD_DATA) && | |
324 | (data_arg.size != I2C_SMBUS_PROC_CALL) && | |
325 | (data_arg.size != I2C_SMBUS_BLOCK_DATA) && | |
326 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) && | |
327 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) && | |
328 | (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
329 | dev_dbg(&client->adapter->dev, | |
330 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
331 | data_arg.size); | |
332 | return -EINVAL; | |
333 | } | |
334 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, | |
335 | so the check is valid if size==I2C_SMBUS_QUICK too. */ | |
336 | if ((data_arg.read_write != I2C_SMBUS_READ) && | |
337 | (data_arg.read_write != I2C_SMBUS_WRITE)) { | |
338 | dev_dbg(&client->adapter->dev, | |
339 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", | |
340 | data_arg.read_write); | |
341 | return -EINVAL; | |
342 | } | |
343 | ||
344 | /* Note that command values are always valid! */ | |
345 | ||
346 | if ((data_arg.size == I2C_SMBUS_QUICK) || | |
347 | ((data_arg.size == I2C_SMBUS_BYTE) && | |
348 | (data_arg.read_write == I2C_SMBUS_WRITE))) | |
349 | /* These are special: we do not use data */ | |
350 | return i2c_smbus_xfer(client->adapter, client->addr, | |
351 | client->flags, data_arg.read_write, | |
352 | data_arg.command, data_arg.size, NULL); | |
353 | ||
354 | if (data_arg.data == NULL) { | |
355 | dev_dbg(&client->adapter->dev, | |
356 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
357 | return -EINVAL; | |
358 | } | |
359 | ||
360 | if ((data_arg.size == I2C_SMBUS_BYTE_DATA) || | |
361 | (data_arg.size == I2C_SMBUS_BYTE)) | |
362 | datasize = sizeof(data_arg.data->byte); | |
363 | else if ((data_arg.size == I2C_SMBUS_WORD_DATA) || | |
364 | (data_arg.size == I2C_SMBUS_PROC_CALL)) | |
365 | datasize = sizeof(data_arg.data->word); | |
366 | else /* size == smbus block, i2c block, or block proc. call */ | |
367 | datasize = sizeof(data_arg.data->block); | |
368 | ||
369 | if ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
370 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
371 | (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) || | |
372 | (data_arg.read_write == I2C_SMBUS_WRITE)) { | |
373 | if (copy_from_user(&temp, data_arg.data, datasize)) | |
374 | return -EFAULT; | |
375 | } | |
376 | if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) { | |
377 | /* Convert old I2C block commands to the new | |
378 | convention. This preserves binary compatibility. */ | |
379 | data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA; | |
380 | if (data_arg.read_write == I2C_SMBUS_READ) | |
381 | temp.block[0] = I2C_SMBUS_BLOCK_MAX; | |
382 | } | |
383 | res = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
384 | data_arg.read_write, data_arg.command, data_arg.size, &temp); | |
385 | if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
386 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
387 | (data_arg.read_write == I2C_SMBUS_READ))) { | |
388 | if (copy_to_user(data_arg.data, &temp, datasize)) | |
389 | return -EFAULT; | |
390 | } | |
391 | return res; | |
392 | } | |
393 | ||
77e38bff | 394 | static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
dba7997a | 395 | { |
0be16c30 | 396 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
397 | unsigned long funcs; |
398 | ||
e8aafcb2 JD |
399 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
400 | cmd, arg); | |
1da177e4 | 401 | |
ae5624fc | 402 | switch (cmd) { |
1da177e4 LT |
403 | case I2C_SLAVE: |
404 | case I2C_SLAVE_FORCE: | |
907135aa DB |
405 | /* NOTE: devices set up to work with "new style" drivers |
406 | * can't use I2C_SLAVE, even when the device node is not | |
407 | * bound to a driver. Only I2C_SLAVE_FORCE will work. | |
408 | * | |
409 | * Setting the PEC flag here won't affect kernel drivers, | |
410 | * which will be using the i2c_client node registered with | |
411 | * the driver model core. Likewise, when that client has | |
412 | * the PEC flag already set, the i2c-dev driver won't see | |
413 | * (or use) this setting. | |
414 | */ | |
438d6c2c | 415 | if ((arg > 0x3ff) || |
1da177e4 LT |
416 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) |
417 | return -EINVAL; | |
bd4217d8 | 418 | if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg)) |
1da177e4 | 419 | return -EBUSY; |
bd4217d8 | 420 | /* REVISIT: address could become busy later */ |
1da177e4 LT |
421 | client->addr = arg; |
422 | return 0; | |
423 | case I2C_TENBIT: | |
424 | if (arg) | |
425 | client->flags |= I2C_M_TEN; | |
426 | else | |
427 | client->flags &= ~I2C_M_TEN; | |
428 | return 0; | |
429 | case I2C_PEC: | |
430 | if (arg) | |
431 | client->flags |= I2C_CLIENT_PEC; | |
432 | else | |
433 | client->flags &= ~I2C_CLIENT_PEC; | |
434 | return 0; | |
435 | case I2C_FUNCS: | |
436 | funcs = i2c_get_functionality(client->adapter); | |
2c003e8e | 437 | return put_user(funcs, (unsigned long __user *)arg); |
1da177e4 LT |
438 | |
439 | case I2C_RDWR: | |
dba7997a | 440 | return i2cdev_ioctl_rdrw(client, arg); |
1da177e4 LT |
441 | |
442 | case I2C_SMBUS: | |
dba7997a | 443 | return i2cdev_ioctl_smbus(client, arg); |
1da177e4 | 444 | |
53be7959 DB |
445 | case I2C_RETRIES: |
446 | client->adapter->retries = arg; | |
447 | break; | |
448 | case I2C_TIMEOUT: | |
cd97f39b JD |
449 | /* For historical reasons, user-space sets the timeout |
450 | * value in units of 10 ms. | |
451 | */ | |
452 | client->adapter->timeout = msecs_to_jiffies(arg * 10); | |
53be7959 | 453 | break; |
1da177e4 | 454 | default: |
53be7959 DB |
455 | /* NOTE: returning a fault code here could cause trouble |
456 | * in buggy userspace code. Some old kernel bugs returned | |
457 | * zero in this case, and userspace code might accidentally | |
458 | * have depended on that bug. | |
459 | */ | |
460 | return -ENOTTY; | |
1da177e4 LT |
461 | } |
462 | return 0; | |
463 | } | |
464 | ||
465 | static int i2cdev_open(struct inode *inode, struct file *file) | |
466 | { | |
467 | unsigned int minor = iminor(inode); | |
468 | struct i2c_client *client; | |
469 | struct i2c_adapter *adap; | |
470 | struct i2c_dev *i2c_dev; | |
471 | ||
472 | i2c_dev = i2c_dev_get_by_minor(minor); | |
9669f541 VS |
473 | if (!i2c_dev) |
474 | return -ENODEV; | |
1da177e4 LT |
475 | |
476 | adap = i2c_get_adapter(i2c_dev->adap->nr); | |
9669f541 VS |
477 | if (!adap) |
478 | return -ENODEV; | |
1da177e4 | 479 | |
907135aa DB |
480 | /* This creates an anonymous i2c_client, which may later be |
481 | * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE. | |
482 | * | |
483 | * This client is ** NEVER REGISTERED ** with the driver model | |
484 | * or I2C core code!! It just holds private copies of addressing | |
485 | * information and maybe a PEC flag. | |
486 | */ | |
22f76e74 | 487 | client = kzalloc(sizeof(*client), GFP_KERNEL); |
1da177e4 LT |
488 | if (!client) { |
489 | i2c_put_adapter(adap); | |
9669f541 | 490 | return -ENOMEM; |
1da177e4 | 491 | } |
22f76e74 | 492 | snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); |
1da177e4 | 493 | |
1da177e4 LT |
494 | client->adapter = adap; |
495 | file->private_data = client; | |
496 | ||
9669f541 | 497 | return 0; |
1da177e4 LT |
498 | } |
499 | ||
500 | static int i2cdev_release(struct inode *inode, struct file *file) | |
501 | { | |
502 | struct i2c_client *client = file->private_data; | |
503 | ||
504 | i2c_put_adapter(client->adapter); | |
505 | kfree(client); | |
506 | file->private_data = NULL; | |
507 | ||
508 | return 0; | |
509 | } | |
510 | ||
2b8693c0 | 511 | static const struct file_operations i2cdev_fops = { |
1da177e4 LT |
512 | .owner = THIS_MODULE, |
513 | .llseek = no_llseek, | |
514 | .read = i2cdev_read, | |
515 | .write = i2cdev_write, | |
77e38bff | 516 | .unlocked_ioctl = i2cdev_ioctl, |
1da177e4 LT |
517 | .open = i2cdev_open, |
518 | .release = i2cdev_release, | |
519 | }; | |
520 | ||
907135aa DB |
521 | /* ------------------------------------------------------------------------- */ |
522 | ||
79472132 | 523 | static struct class *i2c_dev_class; |
1da177e4 | 524 | |
9ea3e941 | 525 | static int i2cdev_attach_adapter(struct device *dev, void *dummy) |
1da177e4 | 526 | { |
9ea3e941 | 527 | struct i2c_adapter *adap; |
1da177e4 | 528 | struct i2c_dev *i2c_dev; |
defcb46e | 529 | int res; |
1da177e4 | 530 | |
9ea3e941 JD |
531 | if (dev->type != &i2c_adapter_type) |
532 | return 0; | |
533 | adap = to_i2c_adapter(dev); | |
534 | ||
1da177e4 LT |
535 | i2c_dev = get_free_i2c_dev(adap); |
536 | if (IS_ERR(i2c_dev)) | |
537 | return PTR_ERR(i2c_dev); | |
538 | ||
1da177e4 | 539 | /* register this i2c device with the driver core */ |
a9b12619 GKH |
540 | i2c_dev->dev = device_create(i2c_dev_class, &adap->dev, |
541 | MKDEV(I2C_MAJOR, adap->nr), NULL, | |
542 | "i2c-%d", adap->nr); | |
3bacb36d AM |
543 | if (IS_ERR(i2c_dev->dev)) { |
544 | res = PTR_ERR(i2c_dev->dev); | |
1da177e4 | 545 | goto error; |
defcb46e | 546 | } |
ac11d060 | 547 | res = device_create_file(i2c_dev->dev, &dev_attr_name); |
defcb46e JD |
548 | if (res) |
549 | goto error_destroy; | |
b32d20dc JD |
550 | |
551 | pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", | |
552 | adap->name, adap->nr); | |
1da177e4 | 553 | return 0; |
defcb46e | 554 | error_destroy: |
ac11d060 | 555 | device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 LT |
556 | error: |
557 | return_i2c_dev(i2c_dev); | |
defcb46e | 558 | return res; |
1da177e4 LT |
559 | } |
560 | ||
9ea3e941 | 561 | static int i2cdev_detach_adapter(struct device *dev, void *dummy) |
1da177e4 | 562 | { |
9ea3e941 | 563 | struct i2c_adapter *adap; |
1da177e4 LT |
564 | struct i2c_dev *i2c_dev; |
565 | ||
9ea3e941 JD |
566 | if (dev->type != &i2c_adapter_type) |
567 | return 0; | |
568 | adap = to_i2c_adapter(dev); | |
569 | ||
9455e4c9 | 570 | i2c_dev = i2c_dev_get_by_minor(adap->nr); |
b32d20dc JD |
571 | if (!i2c_dev) /* attach_adapter must have failed */ |
572 | return 0; | |
1da177e4 | 573 | |
ac11d060 | 574 | device_remove_file(i2c_dev->dev, &dev_attr_name); |
1da177e4 | 575 | return_i2c_dev(i2c_dev); |
ac11d060 | 576 | device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 | 577 | |
b6d7b3d1 | 578 | pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
579 | return 0; |
580 | } | |
581 | ||
eff245c8 | 582 | static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action, |
9ea3e941 JD |
583 | void *data) |
584 | { | |
585 | struct device *dev = data; | |
586 | ||
587 | switch (action) { | |
588 | case BUS_NOTIFY_ADD_DEVICE: | |
589 | return i2cdev_attach_adapter(dev, NULL); | |
590 | case BUS_NOTIFY_DEL_DEVICE: | |
591 | return i2cdev_detach_adapter(dev, NULL); | |
592 | } | |
593 | ||
594 | return 0; | |
595 | } | |
596 | ||
597 | static struct notifier_block i2cdev_notifier = { | |
598 | .notifier_call = i2cdev_notifier_call, | |
1da177e4 LT |
599 | }; |
600 | ||
907135aa DB |
601 | /* ------------------------------------------------------------------------- */ |
602 | ||
603 | /* | |
604 | * module load/unload record keeping | |
605 | */ | |
606 | ||
1da177e4 LT |
607 | static int __init i2c_dev_init(void) |
608 | { | |
609 | int res; | |
610 | ||
611 | printk(KERN_INFO "i2c /dev entries driver\n"); | |
612 | ||
613 | res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops); | |
614 | if (res) | |
615 | goto out; | |
616 | ||
79472132 | 617 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
e74783ec SW |
618 | if (IS_ERR(i2c_dev_class)) { |
619 | res = PTR_ERR(i2c_dev_class); | |
1da177e4 | 620 | goto out_unreg_chrdev; |
e74783ec | 621 | } |
1da177e4 | 622 | |
9ea3e941 JD |
623 | /* Keep track of adapters which will be added or removed later */ |
624 | res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier); | |
1da177e4 LT |
625 | if (res) |
626 | goto out_unreg_class; | |
627 | ||
9ea3e941 JD |
628 | /* Bind to already existing adapters right away */ |
629 | i2c_for_each_dev(NULL, i2cdev_attach_adapter); | |
630 | ||
1da177e4 LT |
631 | return 0; |
632 | ||
633 | out_unreg_class: | |
79472132 | 634 | class_destroy(i2c_dev_class); |
1da177e4 LT |
635 | out_unreg_chrdev: |
636 | unregister_chrdev(I2C_MAJOR, "i2c"); | |
637 | out: | |
638 | printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); | |
639 | return res; | |
640 | } | |
641 | ||
642 | static void __exit i2c_dev_exit(void) | |
643 | { | |
9ea3e941 JD |
644 | bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier); |
645 | i2c_for_each_dev(NULL, i2cdev_detach_adapter); | |
79472132 | 646 | class_destroy(i2c_dev_class); |
ae5624fc | 647 | unregister_chrdev(I2C_MAJOR, "i2c"); |
1da177e4 LT |
648 | } |
649 | ||
650 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
651 | "Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
652 | MODULE_DESCRIPTION("I2C /dev entries driver"); | |
653 | MODULE_LICENSE("GPL"); | |
654 | ||
655 | module_init(i2c_dev_init); | |
656 | module_exit(i2c_dev_exit); |