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. | |
1da177e4 LT |
17 | */ |
18 | ||
19 | /* Note that this is a complete rewrite of Simon Vogl's i2c-dev module. | |
20 | But I have used so much of his original code and ideas that it seems | |
21 | only fair to recognize him as co-author -- Frodo */ | |
22 | ||
23 | /* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */ | |
24 | ||
d6760b14 | 25 | #include <linux/cdev.h> |
9ea3e941 | 26 | #include <linux/device.h> |
1da177e4 | 27 | #include <linux/fs.h> |
1da177e4 | 28 | #include <linux/i2c-dev.h> |
a8766073 WS |
29 | #include <linux/i2c.h> |
30 | #include <linux/init.h> | |
cd97f39b | 31 | #include <linux/jiffies.h> |
a8766073 WS |
32 | #include <linux/kernel.h> |
33 | #include <linux/list.h> | |
34 | #include <linux/module.h> | |
35 | #include <linux/notifier.h> | |
36 | #include <linux/slab.h> | |
ae5624fc | 37 | #include <linux/uaccess.h> |
1da177e4 | 38 | |
907135aa DB |
39 | /* |
40 | * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a | |
41 | * slave (i2c_client) with which messages will be exchanged. It's coupled | |
42 | * with a character special file which is accessed by user mode drivers. | |
43 | * | |
44 | * The list of i2c_dev structures is parallel to the i2c_adapter lists | |
9ea3e941 | 45 | * maintained by the driver model, and is updated using bus notifications. |
907135aa | 46 | */ |
1da177e4 | 47 | struct i2c_dev { |
f3b3aadb | 48 | struct list_head list; |
1da177e4 | 49 | struct i2c_adapter *adap; |
ac11d060 | 50 | struct device *dev; |
d6760b14 | 51 | struct cdev cdev; |
1da177e4 | 52 | }; |
1da177e4 | 53 | |
d6760b14 | 54 | #define I2C_MINORS MINORMASK |
f3b3aadb JD |
55 | static LIST_HEAD(i2c_dev_list); |
56 | static DEFINE_SPINLOCK(i2c_dev_list_lock); | |
1da177e4 LT |
57 | |
58 | static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) | |
59 | { | |
60 | struct i2c_dev *i2c_dev; | |
61 | ||
f3b3aadb JD |
62 | spin_lock(&i2c_dev_list_lock); |
63 | list_for_each_entry(i2c_dev, &i2c_dev_list, list) { | |
64 | if (i2c_dev->adap->nr == index) | |
65 | goto found; | |
66 | } | |
67 | i2c_dev = NULL; | |
68 | found: | |
69 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 LT |
70 | return i2c_dev; |
71 | } | |
72 | ||
1da177e4 LT |
73 | static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) |
74 | { | |
75 | struct i2c_dev *i2c_dev; | |
76 | ||
f3b3aadb JD |
77 | if (adap->nr >= I2C_MINORS) { |
78 | printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n", | |
79 | adap->nr); | |
80 | return ERR_PTR(-ENODEV); | |
81 | } | |
82 | ||
5263ebb5 | 83 | i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); |
1da177e4 LT |
84 | if (!i2c_dev) |
85 | return ERR_PTR(-ENOMEM); | |
9455e4c9 | 86 | i2c_dev->adap = adap; |
f3b3aadb JD |
87 | |
88 | spin_lock(&i2c_dev_list_lock); | |
89 | list_add_tail(&i2c_dev->list, &i2c_dev_list); | |
90 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 | 91 | return i2c_dev; |
1da177e4 LT |
92 | } |
93 | ||
72a71f86 | 94 | static void put_i2c_dev(struct i2c_dev *i2c_dev) |
1da177e4 | 95 | { |
f3b3aadb JD |
96 | spin_lock(&i2c_dev_list_lock); |
97 | list_del(&i2c_dev->list); | |
98 | spin_unlock(&i2c_dev_list_lock); | |
07125ab2 | 99 | kfree(i2c_dev); |
1da177e4 LT |
100 | } |
101 | ||
45f176ae GR |
102 | static ssize_t name_show(struct device *dev, |
103 | struct device_attribute *attr, char *buf) | |
1da177e4 | 104 | { |
ac11d060 | 105 | struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt)); |
79472132 GKH |
106 | |
107 | if (!i2c_dev) | |
108 | return -ENODEV; | |
1da177e4 LT |
109 | return sprintf(buf, "%s\n", i2c_dev->adap->name); |
110 | } | |
45f176ae GR |
111 | static DEVICE_ATTR_RO(name); |
112 | ||
113 | static struct attribute *i2c_attrs[] = { | |
114 | &dev_attr_name.attr, | |
115 | NULL, | |
116 | }; | |
117 | ATTRIBUTE_GROUPS(i2c); | |
1da177e4 | 118 | |
907135aa DB |
119 | /* ------------------------------------------------------------------------- */ |
120 | ||
121 | /* | |
122 | * After opening an instance of this character special file, a file | |
123 | * descriptor starts out associated only with an i2c_adapter (and bus). | |
124 | * | |
125 | * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg | |
126 | * traffic to any devices on the bus used by that adapter. That's because | |
127 | * the i2c_msg vectors embed all the addressing information they need, and | |
128 | * are submitted directly to an i2c_adapter. However, SMBus-only adapters | |
129 | * don't support that interface. | |
130 | * | |
131 | * To use read()/write() system calls on that file descriptor, or to use | |
132 | * SMBus interfaces (and work with SMBus-only hosts!), you must first issue | |
133 | * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous | |
134 | * (never registered) i2c_client so it holds the addressing information | |
135 | * needed by those system calls and by this SMBus interface. | |
136 | */ | |
137 | ||
ae5624fc FH |
138 | static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count, |
139 | loff_t *offset) | |
1da177e4 LT |
140 | { |
141 | char *tmp; | |
142 | int ret; | |
143 | ||
0be16c30 | 144 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
145 | |
146 | if (count > 8192) | |
147 | count = 8192; | |
148 | ||
ae5624fc FH |
149 | tmp = kmalloc(count, GFP_KERNEL); |
150 | if (tmp == NULL) | |
1da177e4 LT |
151 | return -ENOMEM; |
152 | ||
2ce5b34f | 153 | pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n", |
496ad9aa | 154 | iminor(file_inode(file)), count); |
1da177e4 | 155 | |
ae5624fc | 156 | ret = i2c_master_recv(client, tmp, count); |
1da177e4 | 157 | if (ret >= 0) |
ae5624fc | 158 | ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret; |
1da177e4 LT |
159 | kfree(tmp); |
160 | return ret; | |
161 | } | |
162 | ||
ae5624fc FH |
163 | static ssize_t i2cdev_write(struct file *file, const char __user *buf, |
164 | size_t count, loff_t *offset) | |
1da177e4 LT |
165 | { |
166 | int ret; | |
167 | char *tmp; | |
0be16c30 | 168 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
169 | |
170 | if (count > 8192) | |
171 | count = 8192; | |
172 | ||
f1c2e33c JL |
173 | tmp = memdup_user(buf, count); |
174 | if (IS_ERR(tmp)) | |
175 | return PTR_ERR(tmp); | |
1da177e4 | 176 | |
2ce5b34f | 177 | pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n", |
496ad9aa | 178 | iminor(file_inode(file)), count); |
1da177e4 | 179 | |
ae5624fc | 180 | ret = i2c_master_send(client, tmp, count); |
1da177e4 LT |
181 | kfree(tmp); |
182 | return ret; | |
183 | } | |
184 | ||
9b766b81 DB |
185 | static int i2cdev_check(struct device *dev, void *addrp) |
186 | { | |
187 | struct i2c_client *client = i2c_verify_client(dev); | |
188 | ||
189 | if (!client || client->addr != *(unsigned int *)addrp) | |
190 | return 0; | |
191 | ||
192 | return dev->driver ? -EBUSY : 0; | |
193 | } | |
194 | ||
0826374b ML |
195 | /* walk up mux tree */ |
196 | static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
197 | { | |
97cc4d49 | 198 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
199 | int result; |
200 | ||
201 | result = device_for_each_child(&adapter->dev, &addr, i2cdev_check); | |
97cc4d49 JD |
202 | if (!result && parent) |
203 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
204 | |
205 | return result; | |
206 | } | |
207 | ||
208 | /* recurse down mux tree */ | |
209 | static int i2cdev_check_mux_children(struct device *dev, void *addrp) | |
210 | { | |
211 | int result; | |
212 | ||
213 | if (dev->type == &i2c_adapter_type) | |
214 | result = device_for_each_child(dev, addrp, | |
215 | i2cdev_check_mux_children); | |
216 | else | |
217 | result = i2cdev_check(dev, addrp); | |
218 | ||
219 | return result; | |
220 | } | |
221 | ||
bd4217d8 JD |
222 | /* This address checking function differs from the one in i2c-core |
223 | in that it considers an address with a registered device, but no | |
9b766b81 | 224 | driver bound to it, as NOT busy. */ |
bd4217d8 JD |
225 | static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) |
226 | { | |
97cc4d49 | 227 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
228 | int result = 0; |
229 | ||
97cc4d49 JD |
230 | if (parent) |
231 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
232 | |
233 | if (!result) | |
234 | result = device_for_each_child(&adapter->dev, &addr, | |
235 | i2cdev_check_mux_children); | |
236 | ||
237 | return result; | |
bd4217d8 JD |
238 | } |
239 | ||
c57d3e7a | 240 | static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client, |
dba7997a | 241 | unsigned long arg) |
1da177e4 | 242 | { |
1da177e4 | 243 | struct i2c_rdwr_ioctl_data rdwr_arg; |
1da177e4 LT |
244 | struct i2c_msg *rdwr_pa; |
245 | u8 __user **data_ptrs; | |
dba7997a JD |
246 | int i, res; |
247 | ||
248 | if (copy_from_user(&rdwr_arg, | |
249 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
250 | sizeof(rdwr_arg))) | |
251 | return -EFAULT; | |
252 | ||
253 | /* Put an arbitrary limit on the number of messages that can | |
254 | * be sent at once */ | |
c57d3e7a | 255 | if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) |
dba7997a JD |
256 | return -EINVAL; |
257 | ||
a699ed6f TM |
258 | rdwr_pa = memdup_user(rdwr_arg.msgs, |
259 | rdwr_arg.nmsgs * sizeof(struct i2c_msg)); | |
260 | if (IS_ERR(rdwr_pa)) | |
261 | return PTR_ERR(rdwr_pa); | |
dba7997a JD |
262 | |
263 | data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL); | |
264 | if (data_ptrs == NULL) { | |
265 | kfree(rdwr_pa); | |
266 | return -ENOMEM; | |
267 | } | |
268 | ||
269 | res = 0; | |
270 | for (i = 0; i < rdwr_arg.nmsgs; i++) { | |
838bfa60 JD |
271 | /* Limit the size of the message to a sane amount */ |
272 | if (rdwr_pa[i].len > 8192) { | |
dba7997a JD |
273 | res = -EINVAL; |
274 | break; | |
275 | } | |
838bfa60 | 276 | |
dba7997a | 277 | data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; |
f1c2e33c JL |
278 | rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len); |
279 | if (IS_ERR(rdwr_pa[i].buf)) { | |
280 | res = PTR_ERR(rdwr_pa[i].buf); | |
dba7997a JD |
281 | break; |
282 | } | |
838bfa60 JD |
283 | |
284 | /* | |
285 | * If the message length is received from the slave (similar | |
286 | * to SMBus block read), we must ensure that the buffer will | |
287 | * be large enough to cope with a message length of | |
288 | * I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus | |
289 | * drivers allow. The first byte in the buffer must be | |
290 | * pre-filled with the number of extra bytes, which must be | |
291 | * at least one to hold the message length, but can be | |
292 | * greater (for example to account for a checksum byte at | |
293 | * the end of the message.) | |
294 | */ | |
295 | if (rdwr_pa[i].flags & I2C_M_RECV_LEN) { | |
296 | if (!(rdwr_pa[i].flags & I2C_M_RD) || | |
297 | rdwr_pa[i].buf[0] < 1 || | |
298 | rdwr_pa[i].len < rdwr_pa[i].buf[0] + | |
299 | I2C_SMBUS_BLOCK_MAX) { | |
300 | res = -EINVAL; | |
301 | break; | |
302 | } | |
303 | ||
304 | rdwr_pa[i].len = rdwr_pa[i].buf[0]; | |
305 | } | |
dba7997a JD |
306 | } |
307 | if (res < 0) { | |
308 | int j; | |
309 | for (j = 0; j < i; ++j) | |
310 | kfree(rdwr_pa[j].buf); | |
311 | kfree(data_ptrs); | |
312 | kfree(rdwr_pa); | |
313 | return res; | |
314 | } | |
315 | ||
316 | res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs); | |
317 | while (i-- > 0) { | |
318 | if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) { | |
319 | if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf, | |
320 | rdwr_pa[i].len)) | |
321 | res = -EFAULT; | |
322 | } | |
323 | kfree(rdwr_pa[i].buf); | |
324 | } | |
325 | kfree(data_ptrs); | |
326 | kfree(rdwr_pa); | |
327 | return res; | |
328 | } | |
329 | ||
330 | static noinline int i2cdev_ioctl_smbus(struct i2c_client *client, | |
331 | unsigned long arg) | |
332 | { | |
333 | struct i2c_smbus_ioctl_data data_arg; | |
334 | union i2c_smbus_data temp; | |
335 | int datasize, res; | |
336 | ||
337 | if (copy_from_user(&data_arg, | |
338 | (struct i2c_smbus_ioctl_data __user *) arg, | |
339 | sizeof(struct i2c_smbus_ioctl_data))) | |
340 | return -EFAULT; | |
341 | if ((data_arg.size != I2C_SMBUS_BYTE) && | |
342 | (data_arg.size != I2C_SMBUS_QUICK) && | |
343 | (data_arg.size != I2C_SMBUS_BYTE_DATA) && | |
344 | (data_arg.size != I2C_SMBUS_WORD_DATA) && | |
345 | (data_arg.size != I2C_SMBUS_PROC_CALL) && | |
346 | (data_arg.size != I2C_SMBUS_BLOCK_DATA) && | |
347 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) && | |
348 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) && | |
349 | (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
350 | dev_dbg(&client->adapter->dev, | |
351 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
352 | data_arg.size); | |
353 | return -EINVAL; | |
354 | } | |
355 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, | |
356 | so the check is valid if size==I2C_SMBUS_QUICK too. */ | |
357 | if ((data_arg.read_write != I2C_SMBUS_READ) && | |
358 | (data_arg.read_write != I2C_SMBUS_WRITE)) { | |
359 | dev_dbg(&client->adapter->dev, | |
360 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", | |
361 | data_arg.read_write); | |
362 | return -EINVAL; | |
363 | } | |
364 | ||
365 | /* Note that command values are always valid! */ | |
366 | ||
367 | if ((data_arg.size == I2C_SMBUS_QUICK) || | |
368 | ((data_arg.size == I2C_SMBUS_BYTE) && | |
369 | (data_arg.read_write == I2C_SMBUS_WRITE))) | |
370 | /* These are special: we do not use data */ | |
371 | return i2c_smbus_xfer(client->adapter, client->addr, | |
372 | client->flags, data_arg.read_write, | |
373 | data_arg.command, data_arg.size, NULL); | |
374 | ||
375 | if (data_arg.data == NULL) { | |
376 | dev_dbg(&client->adapter->dev, | |
377 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
378 | return -EINVAL; | |
379 | } | |
380 | ||
381 | if ((data_arg.size == I2C_SMBUS_BYTE_DATA) || | |
382 | (data_arg.size == I2C_SMBUS_BYTE)) | |
383 | datasize = sizeof(data_arg.data->byte); | |
384 | else if ((data_arg.size == I2C_SMBUS_WORD_DATA) || | |
385 | (data_arg.size == I2C_SMBUS_PROC_CALL)) | |
386 | datasize = sizeof(data_arg.data->word); | |
387 | else /* size == smbus block, i2c block, or block proc. call */ | |
388 | datasize = sizeof(data_arg.data->block); | |
389 | ||
390 | if ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
391 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
392 | (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) || | |
393 | (data_arg.read_write == I2C_SMBUS_WRITE)) { | |
394 | if (copy_from_user(&temp, data_arg.data, datasize)) | |
395 | return -EFAULT; | |
396 | } | |
397 | if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) { | |
398 | /* Convert old I2C block commands to the new | |
399 | convention. This preserves binary compatibility. */ | |
400 | data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA; | |
401 | if (data_arg.read_write == I2C_SMBUS_READ) | |
402 | temp.block[0] = I2C_SMBUS_BLOCK_MAX; | |
403 | } | |
404 | res = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
405 | data_arg.read_write, data_arg.command, data_arg.size, &temp); | |
406 | if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
407 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
408 | (data_arg.read_write == I2C_SMBUS_READ))) { | |
409 | if (copy_to_user(data_arg.data, &temp, datasize)) | |
410 | return -EFAULT; | |
411 | } | |
412 | return res; | |
413 | } | |
414 | ||
77e38bff | 415 | static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
dba7997a | 416 | { |
0be16c30 | 417 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
418 | unsigned long funcs; |
419 | ||
e8aafcb2 JD |
420 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
421 | cmd, arg); | |
1da177e4 | 422 | |
ae5624fc | 423 | switch (cmd) { |
1da177e4 LT |
424 | case I2C_SLAVE: |
425 | case I2C_SLAVE_FORCE: | |
438d6c2c | 426 | if ((arg > 0x3ff) || |
1da177e4 LT |
427 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) |
428 | return -EINVAL; | |
bd4217d8 | 429 | if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg)) |
1da177e4 | 430 | return -EBUSY; |
bd4217d8 | 431 | /* REVISIT: address could become busy later */ |
1da177e4 LT |
432 | client->addr = arg; |
433 | return 0; | |
434 | case I2C_TENBIT: | |
435 | if (arg) | |
436 | client->flags |= I2C_M_TEN; | |
437 | else | |
438 | client->flags &= ~I2C_M_TEN; | |
439 | return 0; | |
440 | case I2C_PEC: | |
9e685c84 JD |
441 | /* |
442 | * Setting the PEC flag here won't affect kernel drivers, | |
443 | * which will be using the i2c_client node registered with | |
444 | * the driver model core. Likewise, when that client has | |
445 | * the PEC flag already set, the i2c-dev driver won't see | |
446 | * (or use) this setting. | |
447 | */ | |
1da177e4 LT |
448 | if (arg) |
449 | client->flags |= I2C_CLIENT_PEC; | |
450 | else | |
451 | client->flags &= ~I2C_CLIENT_PEC; | |
452 | return 0; | |
453 | case I2C_FUNCS: | |
454 | funcs = i2c_get_functionality(client->adapter); | |
2c003e8e | 455 | return put_user(funcs, (unsigned long __user *)arg); |
1da177e4 LT |
456 | |
457 | case I2C_RDWR: | |
c57d3e7a | 458 | return i2cdev_ioctl_rdwr(client, arg); |
1da177e4 LT |
459 | |
460 | case I2C_SMBUS: | |
dba7997a | 461 | return i2cdev_ioctl_smbus(client, arg); |
1da177e4 | 462 | |
53be7959 DB |
463 | case I2C_RETRIES: |
464 | client->adapter->retries = arg; | |
465 | break; | |
466 | case I2C_TIMEOUT: | |
cd97f39b JD |
467 | /* For historical reasons, user-space sets the timeout |
468 | * value in units of 10 ms. | |
469 | */ | |
470 | client->adapter->timeout = msecs_to_jiffies(arg * 10); | |
53be7959 | 471 | break; |
1da177e4 | 472 | default: |
53be7959 DB |
473 | /* NOTE: returning a fault code here could cause trouble |
474 | * in buggy userspace code. Some old kernel bugs returned | |
475 | * zero in this case, and userspace code might accidentally | |
476 | * have depended on that bug. | |
477 | */ | |
478 | return -ENOTTY; | |
1da177e4 LT |
479 | } |
480 | return 0; | |
481 | } | |
482 | ||
483 | static int i2cdev_open(struct inode *inode, struct file *file) | |
484 | { | |
485 | unsigned int minor = iminor(inode); | |
486 | struct i2c_client *client; | |
487 | struct i2c_adapter *adap; | |
488 | struct i2c_dev *i2c_dev; | |
489 | ||
490 | i2c_dev = i2c_dev_get_by_minor(minor); | |
9669f541 VS |
491 | if (!i2c_dev) |
492 | return -ENODEV; | |
1da177e4 LT |
493 | |
494 | adap = i2c_get_adapter(i2c_dev->adap->nr); | |
9669f541 VS |
495 | if (!adap) |
496 | return -ENODEV; | |
1da177e4 | 497 | |
907135aa DB |
498 | /* This creates an anonymous i2c_client, which may later be |
499 | * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE. | |
500 | * | |
501 | * This client is ** NEVER REGISTERED ** with the driver model | |
502 | * or I2C core code!! It just holds private copies of addressing | |
503 | * information and maybe a PEC flag. | |
504 | */ | |
22f76e74 | 505 | client = kzalloc(sizeof(*client), GFP_KERNEL); |
1da177e4 LT |
506 | if (!client) { |
507 | i2c_put_adapter(adap); | |
9669f541 | 508 | return -ENOMEM; |
1da177e4 | 509 | } |
22f76e74 | 510 | snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); |
1da177e4 | 511 | |
1da177e4 LT |
512 | client->adapter = adap; |
513 | file->private_data = client; | |
514 | ||
9669f541 | 515 | return 0; |
1da177e4 LT |
516 | } |
517 | ||
518 | static int i2cdev_release(struct inode *inode, struct file *file) | |
519 | { | |
520 | struct i2c_client *client = file->private_data; | |
521 | ||
522 | i2c_put_adapter(client->adapter); | |
523 | kfree(client); | |
524 | file->private_data = NULL; | |
525 | ||
526 | return 0; | |
527 | } | |
528 | ||
2b8693c0 | 529 | static const struct file_operations i2cdev_fops = { |
1da177e4 LT |
530 | .owner = THIS_MODULE, |
531 | .llseek = no_llseek, | |
532 | .read = i2cdev_read, | |
533 | .write = i2cdev_write, | |
77e38bff | 534 | .unlocked_ioctl = i2cdev_ioctl, |
1da177e4 LT |
535 | .open = i2cdev_open, |
536 | .release = i2cdev_release, | |
537 | }; | |
538 | ||
907135aa DB |
539 | /* ------------------------------------------------------------------------- */ |
540 | ||
79472132 | 541 | static struct class *i2c_dev_class; |
1da177e4 | 542 | |
9ea3e941 | 543 | static int i2cdev_attach_adapter(struct device *dev, void *dummy) |
1da177e4 | 544 | { |
9ea3e941 | 545 | struct i2c_adapter *adap; |
1da177e4 | 546 | struct i2c_dev *i2c_dev; |
defcb46e | 547 | int res; |
1da177e4 | 548 | |
9ea3e941 JD |
549 | if (dev->type != &i2c_adapter_type) |
550 | return 0; | |
551 | adap = to_i2c_adapter(dev); | |
552 | ||
1da177e4 LT |
553 | i2c_dev = get_free_i2c_dev(adap); |
554 | if (IS_ERR(i2c_dev)) | |
555 | return PTR_ERR(i2c_dev); | |
556 | ||
d6760b14 EN |
557 | cdev_init(&i2c_dev->cdev, &i2cdev_fops); |
558 | i2c_dev->cdev.owner = THIS_MODULE; | |
559 | res = cdev_add(&i2c_dev->cdev, MKDEV(I2C_MAJOR, adap->nr), 1); | |
560 | if (res) | |
561 | goto error_cdev; | |
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: | |
d6760b14 EN |
576 | cdev_del(&i2c_dev->cdev); |
577 | error_cdev: | |
72a71f86 | 578 | put_i2c_dev(i2c_dev); |
defcb46e | 579 | return res; |
1da177e4 LT |
580 | } |
581 | ||
9ea3e941 | 582 | static int i2cdev_detach_adapter(struct device *dev, void *dummy) |
1da177e4 | 583 | { |
9ea3e941 | 584 | struct i2c_adapter *adap; |
1da177e4 LT |
585 | struct i2c_dev *i2c_dev; |
586 | ||
9ea3e941 JD |
587 | if (dev->type != &i2c_adapter_type) |
588 | return 0; | |
589 | adap = to_i2c_adapter(dev); | |
590 | ||
9455e4c9 | 591 | i2c_dev = i2c_dev_get_by_minor(adap->nr); |
b32d20dc JD |
592 | if (!i2c_dev) /* attach_adapter must have failed */ |
593 | return 0; | |
1da177e4 | 594 | |
e6be18f6 | 595 | cdev_del(&i2c_dev->cdev); |
72a71f86 | 596 | put_i2c_dev(i2c_dev); |
ac11d060 | 597 | device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 | 598 | |
b6d7b3d1 | 599 | pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
600 | return 0; |
601 | } | |
602 | ||
eff245c8 | 603 | static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action, |
9ea3e941 JD |
604 | void *data) |
605 | { | |
606 | struct device *dev = data; | |
607 | ||
608 | switch (action) { | |
609 | case BUS_NOTIFY_ADD_DEVICE: | |
610 | return i2cdev_attach_adapter(dev, NULL); | |
611 | case BUS_NOTIFY_DEL_DEVICE: | |
612 | return i2cdev_detach_adapter(dev, NULL); | |
613 | } | |
614 | ||
615 | return 0; | |
616 | } | |
617 | ||
618 | static struct notifier_block i2cdev_notifier = { | |
619 | .notifier_call = i2cdev_notifier_call, | |
1da177e4 LT |
620 | }; |
621 | ||
907135aa DB |
622 | /* ------------------------------------------------------------------------- */ |
623 | ||
624 | /* | |
625 | * module load/unload record keeping | |
626 | */ | |
627 | ||
1da177e4 LT |
628 | static int __init i2c_dev_init(void) |
629 | { | |
630 | int res; | |
631 | ||
632 | printk(KERN_INFO "i2c /dev entries driver\n"); | |
633 | ||
d6760b14 | 634 | res = register_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS, "i2c"); |
1da177e4 LT |
635 | if (res) |
636 | goto out; | |
637 | ||
79472132 | 638 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
e74783ec SW |
639 | if (IS_ERR(i2c_dev_class)) { |
640 | res = PTR_ERR(i2c_dev_class); | |
1da177e4 | 641 | goto out_unreg_chrdev; |
e74783ec | 642 | } |
45f176ae | 643 | i2c_dev_class->dev_groups = i2c_groups; |
1da177e4 | 644 | |
9ea3e941 JD |
645 | /* Keep track of adapters which will be added or removed later */ |
646 | res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier); | |
1da177e4 LT |
647 | if (res) |
648 | goto out_unreg_class; | |
649 | ||
9ea3e941 JD |
650 | /* Bind to already existing adapters right away */ |
651 | i2c_for_each_dev(NULL, i2cdev_attach_adapter); | |
652 | ||
1da177e4 LT |
653 | return 0; |
654 | ||
655 | out_unreg_class: | |
79472132 | 656 | class_destroy(i2c_dev_class); |
1da177e4 | 657 | out_unreg_chrdev: |
d6760b14 | 658 | unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS); |
1da177e4 LT |
659 | out: |
660 | printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); | |
661 | return res; | |
662 | } | |
663 | ||
664 | static void __exit i2c_dev_exit(void) | |
665 | { | |
9ea3e941 JD |
666 | bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier); |
667 | i2c_for_each_dev(NULL, i2cdev_detach_adapter); | |
79472132 | 668 | class_destroy(i2c_dev_class); |
d6760b14 | 669 | unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS); |
1da177e4 LT |
670 | } |
671 | ||
672 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
673 | "Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
674 | MODULE_DESCRIPTION("I2C /dev entries driver"); | |
675 | MODULE_LICENSE("GPL"); | |
676 | ||
677 | module_init(i2c_dev_init); | |
678 | module_exit(i2c_dev_exit); |