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 | ||
45f176ae GR |
105 | static ssize_t name_show(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 | } | |
45f176ae GR |
114 | static DEVICE_ATTR_RO(name); |
115 | ||
116 | static struct attribute *i2c_attrs[] = { | |
117 | &dev_attr_name.attr, | |
118 | NULL, | |
119 | }; | |
120 | ATTRIBUTE_GROUPS(i2c); | |
1da177e4 | 121 | |
907135aa DB |
122 | /* ------------------------------------------------------------------------- */ |
123 | ||
124 | /* | |
125 | * After opening an instance of this character special file, a file | |
126 | * descriptor starts out associated only with an i2c_adapter (and bus). | |
127 | * | |
128 | * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg | |
129 | * traffic to any devices on the bus used by that adapter. That's because | |
130 | * the i2c_msg vectors embed all the addressing information they need, and | |
131 | * are submitted directly to an i2c_adapter. However, SMBus-only adapters | |
132 | * don't support that interface. | |
133 | * | |
134 | * To use read()/write() system calls on that file descriptor, or to use | |
135 | * SMBus interfaces (and work with SMBus-only hosts!), you must first issue | |
136 | * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous | |
137 | * (never registered) i2c_client so it holds the addressing information | |
138 | * needed by those system calls and by this SMBus interface. | |
139 | */ | |
140 | ||
ae5624fc FH |
141 | static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count, |
142 | loff_t *offset) | |
1da177e4 LT |
143 | { |
144 | char *tmp; | |
145 | int ret; | |
146 | ||
0be16c30 | 147 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
148 | |
149 | if (count > 8192) | |
150 | count = 8192; | |
151 | ||
ae5624fc FH |
152 | tmp = kmalloc(count, GFP_KERNEL); |
153 | if (tmp == NULL) | |
1da177e4 LT |
154 | return -ENOMEM; |
155 | ||
2ce5b34f | 156 | pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n", |
496ad9aa | 157 | iminor(file_inode(file)), count); |
1da177e4 | 158 | |
ae5624fc | 159 | ret = i2c_master_recv(client, tmp, count); |
1da177e4 | 160 | if (ret >= 0) |
ae5624fc | 161 | ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret; |
1da177e4 LT |
162 | kfree(tmp); |
163 | return ret; | |
164 | } | |
165 | ||
ae5624fc FH |
166 | static ssize_t i2cdev_write(struct file *file, const char __user *buf, |
167 | size_t count, loff_t *offset) | |
1da177e4 LT |
168 | { |
169 | int ret; | |
170 | char *tmp; | |
0be16c30 | 171 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
172 | |
173 | if (count > 8192) | |
174 | count = 8192; | |
175 | ||
f1c2e33c JL |
176 | tmp = memdup_user(buf, count); |
177 | if (IS_ERR(tmp)) | |
178 | return PTR_ERR(tmp); | |
1da177e4 | 179 | |
2ce5b34f | 180 | pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n", |
496ad9aa | 181 | iminor(file_inode(file)), count); |
1da177e4 | 182 | |
ae5624fc | 183 | ret = i2c_master_send(client, tmp, count); |
1da177e4 LT |
184 | kfree(tmp); |
185 | return ret; | |
186 | } | |
187 | ||
9b766b81 DB |
188 | static int i2cdev_check(struct device *dev, void *addrp) |
189 | { | |
190 | struct i2c_client *client = i2c_verify_client(dev); | |
191 | ||
192 | if (!client || client->addr != *(unsigned int *)addrp) | |
193 | return 0; | |
194 | ||
195 | return dev->driver ? -EBUSY : 0; | |
196 | } | |
197 | ||
0826374b ML |
198 | /* walk up mux tree */ |
199 | static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
200 | { | |
97cc4d49 | 201 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
202 | int result; |
203 | ||
204 | result = device_for_each_child(&adapter->dev, &addr, i2cdev_check); | |
97cc4d49 JD |
205 | if (!result && parent) |
206 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
207 | |
208 | return result; | |
209 | } | |
210 | ||
211 | /* recurse down mux tree */ | |
212 | static int i2cdev_check_mux_children(struct device *dev, void *addrp) | |
213 | { | |
214 | int result; | |
215 | ||
216 | if (dev->type == &i2c_adapter_type) | |
217 | result = device_for_each_child(dev, addrp, | |
218 | i2cdev_check_mux_children); | |
219 | else | |
220 | result = i2cdev_check(dev, addrp); | |
221 | ||
222 | return result; | |
223 | } | |
224 | ||
bd4217d8 JD |
225 | /* This address checking function differs from the one in i2c-core |
226 | in that it considers an address with a registered device, but no | |
9b766b81 | 227 | driver bound to it, as NOT busy. */ |
bd4217d8 JD |
228 | static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) |
229 | { | |
97cc4d49 | 230 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
231 | int result = 0; |
232 | ||
97cc4d49 JD |
233 | if (parent) |
234 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
235 | |
236 | if (!result) | |
237 | result = device_for_each_child(&adapter->dev, &addr, | |
238 | i2cdev_check_mux_children); | |
239 | ||
240 | return result; | |
bd4217d8 JD |
241 | } |
242 | ||
dba7997a JD |
243 | static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client, |
244 | unsigned long arg) | |
1da177e4 | 245 | { |
1da177e4 | 246 | struct i2c_rdwr_ioctl_data rdwr_arg; |
1da177e4 LT |
247 | struct i2c_msg *rdwr_pa; |
248 | u8 __user **data_ptrs; | |
dba7997a JD |
249 | int i, res; |
250 | ||
251 | if (copy_from_user(&rdwr_arg, | |
252 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
253 | sizeof(rdwr_arg))) | |
254 | return -EFAULT; | |
255 | ||
256 | /* Put an arbitrary limit on the number of messages that can | |
257 | * be sent at once */ | |
258 | if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS) | |
259 | return -EINVAL; | |
260 | ||
a699ed6f TM |
261 | rdwr_pa = memdup_user(rdwr_arg.msgs, |
262 | rdwr_arg.nmsgs * sizeof(struct i2c_msg)); | |
263 | if (IS_ERR(rdwr_pa)) | |
264 | return PTR_ERR(rdwr_pa); | |
dba7997a JD |
265 | |
266 | data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL); | |
267 | if (data_ptrs == NULL) { | |
268 | kfree(rdwr_pa); | |
269 | return -ENOMEM; | |
270 | } | |
271 | ||
272 | res = 0; | |
273 | for (i = 0; i < rdwr_arg.nmsgs; i++) { | |
838bfa60 JD |
274 | /* Limit the size of the message to a sane amount */ |
275 | if (rdwr_pa[i].len > 8192) { | |
dba7997a JD |
276 | res = -EINVAL; |
277 | break; | |
278 | } | |
838bfa60 | 279 | |
dba7997a | 280 | data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; |
f1c2e33c JL |
281 | rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len); |
282 | if (IS_ERR(rdwr_pa[i].buf)) { | |
283 | res = PTR_ERR(rdwr_pa[i].buf); | |
dba7997a JD |
284 | break; |
285 | } | |
838bfa60 JD |
286 | |
287 | /* | |
288 | * If the message length is received from the slave (similar | |
289 | * to SMBus block read), we must ensure that the buffer will | |
290 | * be large enough to cope with a message length of | |
291 | * I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus | |
292 | * drivers allow. The first byte in the buffer must be | |
293 | * pre-filled with the number of extra bytes, which must be | |
294 | * at least one to hold the message length, but can be | |
295 | * greater (for example to account for a checksum byte at | |
296 | * the end of the message.) | |
297 | */ | |
298 | if (rdwr_pa[i].flags & I2C_M_RECV_LEN) { | |
299 | if (!(rdwr_pa[i].flags & I2C_M_RD) || | |
300 | rdwr_pa[i].buf[0] < 1 || | |
301 | rdwr_pa[i].len < rdwr_pa[i].buf[0] + | |
302 | I2C_SMBUS_BLOCK_MAX) { | |
303 | res = -EINVAL; | |
304 | break; | |
305 | } | |
306 | ||
307 | rdwr_pa[i].len = rdwr_pa[i].buf[0]; | |
308 | } | |
dba7997a JD |
309 | } |
310 | if (res < 0) { | |
311 | int j; | |
312 | for (j = 0; j < i; ++j) | |
313 | kfree(rdwr_pa[j].buf); | |
314 | kfree(data_ptrs); | |
315 | kfree(rdwr_pa); | |
316 | return res; | |
317 | } | |
318 | ||
319 | res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs); | |
320 | while (i-- > 0) { | |
321 | if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) { | |
322 | if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf, | |
323 | rdwr_pa[i].len)) | |
324 | res = -EFAULT; | |
325 | } | |
326 | kfree(rdwr_pa[i].buf); | |
327 | } | |
328 | kfree(data_ptrs); | |
329 | kfree(rdwr_pa); | |
330 | return res; | |
331 | } | |
332 | ||
333 | static noinline int i2cdev_ioctl_smbus(struct i2c_client *client, | |
334 | unsigned long arg) | |
335 | { | |
336 | struct i2c_smbus_ioctl_data data_arg; | |
337 | union i2c_smbus_data temp; | |
338 | int datasize, res; | |
339 | ||
340 | if (copy_from_user(&data_arg, | |
341 | (struct i2c_smbus_ioctl_data __user *) arg, | |
342 | sizeof(struct i2c_smbus_ioctl_data))) | |
343 | return -EFAULT; | |
344 | if ((data_arg.size != I2C_SMBUS_BYTE) && | |
345 | (data_arg.size != I2C_SMBUS_QUICK) && | |
346 | (data_arg.size != I2C_SMBUS_BYTE_DATA) && | |
347 | (data_arg.size != I2C_SMBUS_WORD_DATA) && | |
348 | (data_arg.size != I2C_SMBUS_PROC_CALL) && | |
349 | (data_arg.size != I2C_SMBUS_BLOCK_DATA) && | |
350 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) && | |
351 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) && | |
352 | (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
353 | dev_dbg(&client->adapter->dev, | |
354 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
355 | data_arg.size); | |
356 | return -EINVAL; | |
357 | } | |
358 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, | |
359 | so the check is valid if size==I2C_SMBUS_QUICK too. */ | |
360 | if ((data_arg.read_write != I2C_SMBUS_READ) && | |
361 | (data_arg.read_write != I2C_SMBUS_WRITE)) { | |
362 | dev_dbg(&client->adapter->dev, | |
363 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", | |
364 | data_arg.read_write); | |
365 | return -EINVAL; | |
366 | } | |
367 | ||
368 | /* Note that command values are always valid! */ | |
369 | ||
370 | if ((data_arg.size == I2C_SMBUS_QUICK) || | |
371 | ((data_arg.size == I2C_SMBUS_BYTE) && | |
372 | (data_arg.read_write == I2C_SMBUS_WRITE))) | |
373 | /* These are special: we do not use data */ | |
374 | return i2c_smbus_xfer(client->adapter, client->addr, | |
375 | client->flags, data_arg.read_write, | |
376 | data_arg.command, data_arg.size, NULL); | |
377 | ||
378 | if (data_arg.data == NULL) { | |
379 | dev_dbg(&client->adapter->dev, | |
380 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
381 | return -EINVAL; | |
382 | } | |
383 | ||
384 | if ((data_arg.size == I2C_SMBUS_BYTE_DATA) || | |
385 | (data_arg.size == I2C_SMBUS_BYTE)) | |
386 | datasize = sizeof(data_arg.data->byte); | |
387 | else if ((data_arg.size == I2C_SMBUS_WORD_DATA) || | |
388 | (data_arg.size == I2C_SMBUS_PROC_CALL)) | |
389 | datasize = sizeof(data_arg.data->word); | |
390 | else /* size == smbus block, i2c block, or block proc. call */ | |
391 | datasize = sizeof(data_arg.data->block); | |
392 | ||
393 | if ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
394 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
395 | (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) || | |
396 | (data_arg.read_write == I2C_SMBUS_WRITE)) { | |
397 | if (copy_from_user(&temp, data_arg.data, datasize)) | |
398 | return -EFAULT; | |
399 | } | |
400 | if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) { | |
401 | /* Convert old I2C block commands to the new | |
402 | convention. This preserves binary compatibility. */ | |
403 | data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA; | |
404 | if (data_arg.read_write == I2C_SMBUS_READ) | |
405 | temp.block[0] = I2C_SMBUS_BLOCK_MAX; | |
406 | } | |
407 | res = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
408 | data_arg.read_write, data_arg.command, data_arg.size, &temp); | |
409 | if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
410 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
411 | (data_arg.read_write == I2C_SMBUS_READ))) { | |
412 | if (copy_to_user(data_arg.data, &temp, datasize)) | |
413 | return -EFAULT; | |
414 | } | |
415 | return res; | |
416 | } | |
417 | ||
77e38bff | 418 | static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
dba7997a | 419 | { |
0be16c30 | 420 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
421 | unsigned long funcs; |
422 | ||
e8aafcb2 JD |
423 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
424 | cmd, arg); | |
1da177e4 | 425 | |
ae5624fc | 426 | switch (cmd) { |
1da177e4 LT |
427 | case I2C_SLAVE: |
428 | case I2C_SLAVE_FORCE: | |
907135aa DB |
429 | /* NOTE: devices set up to work with "new style" drivers |
430 | * can't use I2C_SLAVE, even when the device node is not | |
431 | * bound to a driver. Only I2C_SLAVE_FORCE will work. | |
432 | * | |
433 | * Setting the PEC flag here won't affect kernel drivers, | |
434 | * which will be using the i2c_client node registered with | |
435 | * the driver model core. Likewise, when that client has | |
436 | * the PEC flag already set, the i2c-dev driver won't see | |
437 | * (or use) this setting. | |
438 | */ | |
438d6c2c | 439 | if ((arg > 0x3ff) || |
1da177e4 LT |
440 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) |
441 | return -EINVAL; | |
bd4217d8 | 442 | if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg)) |
1da177e4 | 443 | return -EBUSY; |
bd4217d8 | 444 | /* REVISIT: address could become busy later */ |
1da177e4 LT |
445 | client->addr = arg; |
446 | return 0; | |
447 | case I2C_TENBIT: | |
448 | if (arg) | |
449 | client->flags |= I2C_M_TEN; | |
450 | else | |
451 | client->flags &= ~I2C_M_TEN; | |
452 | return 0; | |
453 | case I2C_PEC: | |
454 | if (arg) | |
455 | client->flags |= I2C_CLIENT_PEC; | |
456 | else | |
457 | client->flags &= ~I2C_CLIENT_PEC; | |
458 | return 0; | |
459 | case I2C_FUNCS: | |
460 | funcs = i2c_get_functionality(client->adapter); | |
2c003e8e | 461 | return put_user(funcs, (unsigned long __user *)arg); |
1da177e4 LT |
462 | |
463 | case I2C_RDWR: | |
dba7997a | 464 | return i2cdev_ioctl_rdrw(client, arg); |
1da177e4 LT |
465 | |
466 | case I2C_SMBUS: | |
dba7997a | 467 | return i2cdev_ioctl_smbus(client, arg); |
1da177e4 | 468 | |
53be7959 DB |
469 | case I2C_RETRIES: |
470 | client->adapter->retries = arg; | |
471 | break; | |
472 | case I2C_TIMEOUT: | |
cd97f39b JD |
473 | /* For historical reasons, user-space sets the timeout |
474 | * value in units of 10 ms. | |
475 | */ | |
476 | client->adapter->timeout = msecs_to_jiffies(arg * 10); | |
53be7959 | 477 | break; |
1da177e4 | 478 | default: |
53be7959 DB |
479 | /* NOTE: returning a fault code here could cause trouble |
480 | * in buggy userspace code. Some old kernel bugs returned | |
481 | * zero in this case, and userspace code might accidentally | |
482 | * have depended on that bug. | |
483 | */ | |
484 | return -ENOTTY; | |
1da177e4 LT |
485 | } |
486 | return 0; | |
487 | } | |
488 | ||
489 | static int i2cdev_open(struct inode *inode, struct file *file) | |
490 | { | |
491 | unsigned int minor = iminor(inode); | |
492 | struct i2c_client *client; | |
493 | struct i2c_adapter *adap; | |
494 | struct i2c_dev *i2c_dev; | |
495 | ||
496 | i2c_dev = i2c_dev_get_by_minor(minor); | |
9669f541 VS |
497 | if (!i2c_dev) |
498 | return -ENODEV; | |
1da177e4 LT |
499 | |
500 | adap = i2c_get_adapter(i2c_dev->adap->nr); | |
9669f541 VS |
501 | if (!adap) |
502 | return -ENODEV; | |
1da177e4 | 503 | |
907135aa DB |
504 | /* This creates an anonymous i2c_client, which may later be |
505 | * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE. | |
506 | * | |
507 | * This client is ** NEVER REGISTERED ** with the driver model | |
508 | * or I2C core code!! It just holds private copies of addressing | |
509 | * information and maybe a PEC flag. | |
510 | */ | |
22f76e74 | 511 | client = kzalloc(sizeof(*client), GFP_KERNEL); |
1da177e4 LT |
512 | if (!client) { |
513 | i2c_put_adapter(adap); | |
9669f541 | 514 | return -ENOMEM; |
1da177e4 | 515 | } |
22f76e74 | 516 | snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); |
1da177e4 | 517 | |
1da177e4 LT |
518 | client->adapter = adap; |
519 | file->private_data = client; | |
520 | ||
9669f541 | 521 | return 0; |
1da177e4 LT |
522 | } |
523 | ||
524 | static int i2cdev_release(struct inode *inode, struct file *file) | |
525 | { | |
526 | struct i2c_client *client = file->private_data; | |
527 | ||
528 | i2c_put_adapter(client->adapter); | |
529 | kfree(client); | |
530 | file->private_data = NULL; | |
531 | ||
532 | return 0; | |
533 | } | |
534 | ||
2b8693c0 | 535 | static const struct file_operations i2cdev_fops = { |
1da177e4 LT |
536 | .owner = THIS_MODULE, |
537 | .llseek = no_llseek, | |
538 | .read = i2cdev_read, | |
539 | .write = i2cdev_write, | |
77e38bff | 540 | .unlocked_ioctl = i2cdev_ioctl, |
1da177e4 LT |
541 | .open = i2cdev_open, |
542 | .release = i2cdev_release, | |
543 | }; | |
544 | ||
907135aa DB |
545 | /* ------------------------------------------------------------------------- */ |
546 | ||
79472132 | 547 | static struct class *i2c_dev_class; |
1da177e4 | 548 | |
9ea3e941 | 549 | static int i2cdev_attach_adapter(struct device *dev, void *dummy) |
1da177e4 | 550 | { |
9ea3e941 | 551 | struct i2c_adapter *adap; |
1da177e4 | 552 | struct i2c_dev *i2c_dev; |
defcb46e | 553 | int res; |
1da177e4 | 554 | |
9ea3e941 JD |
555 | if (dev->type != &i2c_adapter_type) |
556 | return 0; | |
557 | adap = to_i2c_adapter(dev); | |
558 | ||
1da177e4 LT |
559 | i2c_dev = get_free_i2c_dev(adap); |
560 | if (IS_ERR(i2c_dev)) | |
561 | return PTR_ERR(i2c_dev); | |
562 | ||
1da177e4 | 563 | /* register this i2c device with the driver core */ |
a9b12619 GKH |
564 | i2c_dev->dev = device_create(i2c_dev_class, &adap->dev, |
565 | MKDEV(I2C_MAJOR, adap->nr), NULL, | |
566 | "i2c-%d", adap->nr); | |
3bacb36d AM |
567 | if (IS_ERR(i2c_dev->dev)) { |
568 | res = PTR_ERR(i2c_dev->dev); | |
1da177e4 | 569 | goto error; |
defcb46e | 570 | } |
b32d20dc JD |
571 | |
572 | pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", | |
573 | adap->name, adap->nr); | |
1da177e4 LT |
574 | return 0; |
575 | error: | |
576 | return_i2c_dev(i2c_dev); | |
defcb46e | 577 | return res; |
1da177e4 LT |
578 | } |
579 | ||
9ea3e941 | 580 | static int i2cdev_detach_adapter(struct device *dev, void *dummy) |
1da177e4 | 581 | { |
9ea3e941 | 582 | struct i2c_adapter *adap; |
1da177e4 LT |
583 | struct i2c_dev *i2c_dev; |
584 | ||
9ea3e941 JD |
585 | if (dev->type != &i2c_adapter_type) |
586 | return 0; | |
587 | adap = to_i2c_adapter(dev); | |
588 | ||
9455e4c9 | 589 | i2c_dev = i2c_dev_get_by_minor(adap->nr); |
b32d20dc JD |
590 | if (!i2c_dev) /* attach_adapter must have failed */ |
591 | return 0; | |
1da177e4 | 592 | |
1da177e4 | 593 | return_i2c_dev(i2c_dev); |
ac11d060 | 594 | device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 | 595 | |
b6d7b3d1 | 596 | pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
597 | return 0; |
598 | } | |
599 | ||
eff245c8 | 600 | static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action, |
9ea3e941 JD |
601 | void *data) |
602 | { | |
603 | struct device *dev = data; | |
604 | ||
605 | switch (action) { | |
606 | case BUS_NOTIFY_ADD_DEVICE: | |
607 | return i2cdev_attach_adapter(dev, NULL); | |
608 | case BUS_NOTIFY_DEL_DEVICE: | |
609 | return i2cdev_detach_adapter(dev, NULL); | |
610 | } | |
611 | ||
612 | return 0; | |
613 | } | |
614 | ||
615 | static struct notifier_block i2cdev_notifier = { | |
616 | .notifier_call = i2cdev_notifier_call, | |
1da177e4 LT |
617 | }; |
618 | ||
907135aa DB |
619 | /* ------------------------------------------------------------------------- */ |
620 | ||
621 | /* | |
622 | * module load/unload record keeping | |
623 | */ | |
624 | ||
1da177e4 LT |
625 | static int __init i2c_dev_init(void) |
626 | { | |
627 | int res; | |
628 | ||
629 | printk(KERN_INFO "i2c /dev entries driver\n"); | |
630 | ||
631 | res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops); | |
632 | if (res) | |
633 | goto out; | |
634 | ||
79472132 | 635 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
e74783ec SW |
636 | if (IS_ERR(i2c_dev_class)) { |
637 | res = PTR_ERR(i2c_dev_class); | |
1da177e4 | 638 | goto out_unreg_chrdev; |
e74783ec | 639 | } |
45f176ae | 640 | i2c_dev_class->dev_groups = i2c_groups; |
1da177e4 | 641 | |
9ea3e941 JD |
642 | /* Keep track of adapters which will be added or removed later */ |
643 | res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier); | |
1da177e4 LT |
644 | if (res) |
645 | goto out_unreg_class; | |
646 | ||
9ea3e941 JD |
647 | /* Bind to already existing adapters right away */ |
648 | i2c_for_each_dev(NULL, i2cdev_attach_adapter); | |
649 | ||
1da177e4 LT |
650 | return 0; |
651 | ||
652 | out_unreg_class: | |
79472132 | 653 | class_destroy(i2c_dev_class); |
1da177e4 LT |
654 | out_unreg_chrdev: |
655 | unregister_chrdev(I2C_MAJOR, "i2c"); | |
656 | out: | |
657 | printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); | |
658 | return res; | |
659 | } | |
660 | ||
661 | static void __exit i2c_dev_exit(void) | |
662 | { | |
9ea3e941 JD |
663 | bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier); |
664 | i2c_for_each_dev(NULL, i2cdev_detach_adapter); | |
79472132 | 665 | class_destroy(i2c_dev_class); |
ae5624fc | 666 | unregister_chrdev(I2C_MAJOR, "i2c"); |
1da177e4 LT |
667 | } |
668 | ||
669 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
670 | "Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
671 | MODULE_DESCRIPTION("I2C /dev entries driver"); | |
672 | MODULE_LICENSE("GPL"); | |
673 | ||
674 | module_init(i2c_dev_init); | |
675 | module_exit(i2c_dev_exit); |