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 | ||
9ea3e941 | 25 | #include <linux/device.h> |
1da177e4 | 26 | #include <linux/fs.h> |
1da177e4 | 27 | #include <linux/i2c-dev.h> |
a8766073 WS |
28 | #include <linux/i2c.h> |
29 | #include <linux/init.h> | |
cd97f39b | 30 | #include <linux/jiffies.h> |
a8766073 WS |
31 | #include <linux/kernel.h> |
32 | #include <linux/list.h> | |
33 | #include <linux/module.h> | |
34 | #include <linux/notifier.h> | |
35 | #include <linux/slab.h> | |
ae5624fc | 36 | #include <linux/uaccess.h> |
1da177e4 | 37 | |
907135aa DB |
38 | /* |
39 | * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a | |
40 | * slave (i2c_client) with which messages will be exchanged. It's coupled | |
41 | * with a character special file which is accessed by user mode drivers. | |
42 | * | |
43 | * The list of i2c_dev structures is parallel to the i2c_adapter lists | |
9ea3e941 | 44 | * maintained by the driver model, and is updated using bus notifications. |
907135aa | 45 | */ |
1da177e4 | 46 | struct i2c_dev { |
f3b3aadb | 47 | struct list_head list; |
1da177e4 | 48 | struct i2c_adapter *adap; |
ac11d060 | 49 | struct device *dev; |
1da177e4 | 50 | }; |
1da177e4 LT |
51 | |
52 | #define I2C_MINORS 256 | |
f3b3aadb JD |
53 | static LIST_HEAD(i2c_dev_list); |
54 | static DEFINE_SPINLOCK(i2c_dev_list_lock); | |
1da177e4 LT |
55 | |
56 | static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) | |
57 | { | |
58 | struct i2c_dev *i2c_dev; | |
59 | ||
f3b3aadb JD |
60 | spin_lock(&i2c_dev_list_lock); |
61 | list_for_each_entry(i2c_dev, &i2c_dev_list, list) { | |
62 | if (i2c_dev->adap->nr == index) | |
63 | goto found; | |
64 | } | |
65 | i2c_dev = NULL; | |
66 | found: | |
67 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 LT |
68 | return i2c_dev; |
69 | } | |
70 | ||
1da177e4 LT |
71 | static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) |
72 | { | |
73 | struct i2c_dev *i2c_dev; | |
74 | ||
f3b3aadb JD |
75 | if (adap->nr >= I2C_MINORS) { |
76 | printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n", | |
77 | adap->nr); | |
78 | return ERR_PTR(-ENODEV); | |
79 | } | |
80 | ||
5263ebb5 | 81 | i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); |
1da177e4 LT |
82 | if (!i2c_dev) |
83 | return ERR_PTR(-ENOMEM); | |
9455e4c9 | 84 | i2c_dev->adap = adap; |
f3b3aadb JD |
85 | |
86 | spin_lock(&i2c_dev_list_lock); | |
87 | list_add_tail(&i2c_dev->list, &i2c_dev_list); | |
88 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 | 89 | return i2c_dev; |
1da177e4 LT |
90 | } |
91 | ||
92 | static void return_i2c_dev(struct i2c_dev *i2c_dev) | |
93 | { | |
f3b3aadb JD |
94 | spin_lock(&i2c_dev_list_lock); |
95 | list_del(&i2c_dev->list); | |
96 | spin_unlock(&i2c_dev_list_lock); | |
07125ab2 | 97 | kfree(i2c_dev); |
1da177e4 LT |
98 | } |
99 | ||
45f176ae GR |
100 | static ssize_t name_show(struct device *dev, |
101 | struct device_attribute *attr, char *buf) | |
1da177e4 | 102 | { |
ac11d060 | 103 | struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt)); |
79472132 GKH |
104 | |
105 | if (!i2c_dev) | |
106 | return -ENODEV; | |
1da177e4 LT |
107 | return sprintf(buf, "%s\n", i2c_dev->adap->name); |
108 | } | |
45f176ae GR |
109 | static DEVICE_ATTR_RO(name); |
110 | ||
111 | static struct attribute *i2c_attrs[] = { | |
112 | &dev_attr_name.attr, | |
113 | NULL, | |
114 | }; | |
115 | ATTRIBUTE_GROUPS(i2c); | |
1da177e4 | 116 | |
907135aa DB |
117 | /* ------------------------------------------------------------------------- */ |
118 | ||
119 | /* | |
120 | * After opening an instance of this character special file, a file | |
121 | * descriptor starts out associated only with an i2c_adapter (and bus). | |
122 | * | |
123 | * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg | |
124 | * traffic to any devices on the bus used by that adapter. That's because | |
125 | * the i2c_msg vectors embed all the addressing information they need, and | |
126 | * are submitted directly to an i2c_adapter. However, SMBus-only adapters | |
127 | * don't support that interface. | |
128 | * | |
129 | * To use read()/write() system calls on that file descriptor, or to use | |
130 | * SMBus interfaces (and work with SMBus-only hosts!), you must first issue | |
131 | * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous | |
132 | * (never registered) i2c_client so it holds the addressing information | |
133 | * needed by those system calls and by this SMBus interface. | |
134 | */ | |
135 | ||
ae5624fc FH |
136 | static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count, |
137 | loff_t *offset) | |
1da177e4 LT |
138 | { |
139 | char *tmp; | |
140 | int ret; | |
141 | ||
0be16c30 | 142 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
143 | |
144 | if (count > 8192) | |
145 | count = 8192; | |
146 | ||
ae5624fc FH |
147 | tmp = kmalloc(count, GFP_KERNEL); |
148 | if (tmp == NULL) | |
1da177e4 LT |
149 | return -ENOMEM; |
150 | ||
2ce5b34f | 151 | pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n", |
496ad9aa | 152 | iminor(file_inode(file)), count); |
1da177e4 | 153 | |
ae5624fc | 154 | ret = i2c_master_recv(client, tmp, count); |
1da177e4 | 155 | if (ret >= 0) |
ae5624fc | 156 | ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret; |
1da177e4 LT |
157 | kfree(tmp); |
158 | return ret; | |
159 | } | |
160 | ||
ae5624fc FH |
161 | static ssize_t i2cdev_write(struct file *file, const char __user *buf, |
162 | size_t count, loff_t *offset) | |
1da177e4 LT |
163 | { |
164 | int ret; | |
165 | char *tmp; | |
0be16c30 | 166 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
167 | |
168 | if (count > 8192) | |
169 | count = 8192; | |
170 | ||
f1c2e33c JL |
171 | tmp = memdup_user(buf, count); |
172 | if (IS_ERR(tmp)) | |
173 | return PTR_ERR(tmp); | |
1da177e4 | 174 | |
2ce5b34f | 175 | pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n", |
496ad9aa | 176 | iminor(file_inode(file)), count); |
1da177e4 | 177 | |
ae5624fc | 178 | ret = i2c_master_send(client, tmp, count); |
1da177e4 LT |
179 | kfree(tmp); |
180 | return ret; | |
181 | } | |
182 | ||
9b766b81 DB |
183 | static int i2cdev_check(struct device *dev, void *addrp) |
184 | { | |
185 | struct i2c_client *client = i2c_verify_client(dev); | |
186 | ||
187 | if (!client || client->addr != *(unsigned int *)addrp) | |
188 | return 0; | |
189 | ||
190 | return dev->driver ? -EBUSY : 0; | |
191 | } | |
192 | ||
0826374b ML |
193 | /* walk up mux tree */ |
194 | static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
195 | { | |
97cc4d49 | 196 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
197 | int result; |
198 | ||
199 | result = device_for_each_child(&adapter->dev, &addr, i2cdev_check); | |
97cc4d49 JD |
200 | if (!result && parent) |
201 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
202 | |
203 | return result; | |
204 | } | |
205 | ||
206 | /* recurse down mux tree */ | |
207 | static int i2cdev_check_mux_children(struct device *dev, void *addrp) | |
208 | { | |
209 | int result; | |
210 | ||
211 | if (dev->type == &i2c_adapter_type) | |
212 | result = device_for_each_child(dev, addrp, | |
213 | i2cdev_check_mux_children); | |
214 | else | |
215 | result = i2cdev_check(dev, addrp); | |
216 | ||
217 | return result; | |
218 | } | |
219 | ||
bd4217d8 JD |
220 | /* This address checking function differs from the one in i2c-core |
221 | in that it considers an address with a registered device, but no | |
9b766b81 | 222 | driver bound to it, as NOT busy. */ |
bd4217d8 JD |
223 | static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) |
224 | { | |
97cc4d49 | 225 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
226 | int result = 0; |
227 | ||
97cc4d49 JD |
228 | if (parent) |
229 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
230 | |
231 | if (!result) | |
232 | result = device_for_each_child(&adapter->dev, &addr, | |
233 | i2cdev_check_mux_children); | |
234 | ||
235 | return result; | |
bd4217d8 JD |
236 | } |
237 | ||
c57d3e7a | 238 | static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client, |
dba7997a | 239 | unsigned long arg) |
1da177e4 | 240 | { |
1da177e4 | 241 | struct i2c_rdwr_ioctl_data rdwr_arg; |
1da177e4 LT |
242 | struct i2c_msg *rdwr_pa; |
243 | u8 __user **data_ptrs; | |
dba7997a JD |
244 | int i, res; |
245 | ||
246 | if (copy_from_user(&rdwr_arg, | |
247 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
248 | sizeof(rdwr_arg))) | |
249 | return -EFAULT; | |
250 | ||
251 | /* Put an arbitrary limit on the number of messages that can | |
252 | * be sent at once */ | |
c57d3e7a | 253 | if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) |
dba7997a JD |
254 | return -EINVAL; |
255 | ||
a699ed6f TM |
256 | rdwr_pa = memdup_user(rdwr_arg.msgs, |
257 | rdwr_arg.nmsgs * sizeof(struct i2c_msg)); | |
258 | if (IS_ERR(rdwr_pa)) | |
259 | return PTR_ERR(rdwr_pa); | |
dba7997a JD |
260 | |
261 | data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL); | |
262 | if (data_ptrs == NULL) { | |
263 | kfree(rdwr_pa); | |
264 | return -ENOMEM; | |
265 | } | |
266 | ||
267 | res = 0; | |
268 | for (i = 0; i < rdwr_arg.nmsgs; i++) { | |
838bfa60 JD |
269 | /* Limit the size of the message to a sane amount */ |
270 | if (rdwr_pa[i].len > 8192) { | |
dba7997a JD |
271 | res = -EINVAL; |
272 | break; | |
273 | } | |
838bfa60 | 274 | |
dba7997a | 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 | } | |
838bfa60 JD |
281 | |
282 | /* | |
283 | * If the message length is received from the slave (similar | |
284 | * to SMBus block read), we must ensure that the buffer will | |
285 | * be large enough to cope with a message length of | |
286 | * I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus | |
287 | * drivers allow. The first byte in the buffer must be | |
288 | * pre-filled with the number of extra bytes, which must be | |
289 | * at least one to hold the message length, but can be | |
290 | * greater (for example to account for a checksum byte at | |
291 | * the end of the message.) | |
292 | */ | |
293 | if (rdwr_pa[i].flags & I2C_M_RECV_LEN) { | |
294 | if (!(rdwr_pa[i].flags & I2C_M_RD) || | |
295 | rdwr_pa[i].buf[0] < 1 || | |
296 | rdwr_pa[i].len < rdwr_pa[i].buf[0] + | |
297 | I2C_SMBUS_BLOCK_MAX) { | |
298 | res = -EINVAL; | |
299 | break; | |
300 | } | |
301 | ||
302 | rdwr_pa[i].len = rdwr_pa[i].buf[0]; | |
303 | } | |
dba7997a JD |
304 | } |
305 | if (res < 0) { | |
306 | int j; | |
307 | for (j = 0; j < i; ++j) | |
308 | kfree(rdwr_pa[j].buf); | |
309 | kfree(data_ptrs); | |
310 | kfree(rdwr_pa); | |
311 | return res; | |
312 | } | |
313 | ||
314 | res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs); | |
315 | while (i-- > 0) { | |
316 | if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) { | |
317 | if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf, | |
318 | rdwr_pa[i].len)) | |
319 | res = -EFAULT; | |
320 | } | |
321 | kfree(rdwr_pa[i].buf); | |
322 | } | |
323 | kfree(data_ptrs); | |
324 | kfree(rdwr_pa); | |
325 | return res; | |
326 | } | |
327 | ||
328 | static noinline int i2cdev_ioctl_smbus(struct i2c_client *client, | |
329 | unsigned long arg) | |
330 | { | |
331 | struct i2c_smbus_ioctl_data data_arg; | |
332 | union i2c_smbus_data temp; | |
333 | int datasize, res; | |
334 | ||
335 | if (copy_from_user(&data_arg, | |
336 | (struct i2c_smbus_ioctl_data __user *) arg, | |
337 | sizeof(struct i2c_smbus_ioctl_data))) | |
338 | return -EFAULT; | |
339 | if ((data_arg.size != I2C_SMBUS_BYTE) && | |
340 | (data_arg.size != I2C_SMBUS_QUICK) && | |
341 | (data_arg.size != I2C_SMBUS_BYTE_DATA) && | |
342 | (data_arg.size != I2C_SMBUS_WORD_DATA) && | |
343 | (data_arg.size != I2C_SMBUS_PROC_CALL) && | |
344 | (data_arg.size != I2C_SMBUS_BLOCK_DATA) && | |
345 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) && | |
346 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) && | |
347 | (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
348 | dev_dbg(&client->adapter->dev, | |
349 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
350 | data_arg.size); | |
351 | return -EINVAL; | |
352 | } | |
353 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, | |
354 | so the check is valid if size==I2C_SMBUS_QUICK too. */ | |
355 | if ((data_arg.read_write != I2C_SMBUS_READ) && | |
356 | (data_arg.read_write != I2C_SMBUS_WRITE)) { | |
357 | dev_dbg(&client->adapter->dev, | |
358 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", | |
359 | data_arg.read_write); | |
360 | return -EINVAL; | |
361 | } | |
362 | ||
363 | /* Note that command values are always valid! */ | |
364 | ||
365 | if ((data_arg.size == I2C_SMBUS_QUICK) || | |
366 | ((data_arg.size == I2C_SMBUS_BYTE) && | |
367 | (data_arg.read_write == I2C_SMBUS_WRITE))) | |
368 | /* These are special: we do not use data */ | |
369 | return i2c_smbus_xfer(client->adapter, client->addr, | |
370 | client->flags, data_arg.read_write, | |
371 | data_arg.command, data_arg.size, NULL); | |
372 | ||
373 | if (data_arg.data == NULL) { | |
374 | dev_dbg(&client->adapter->dev, | |
375 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
376 | return -EINVAL; | |
377 | } | |
378 | ||
379 | if ((data_arg.size == I2C_SMBUS_BYTE_DATA) || | |
380 | (data_arg.size == I2C_SMBUS_BYTE)) | |
381 | datasize = sizeof(data_arg.data->byte); | |
382 | else if ((data_arg.size == I2C_SMBUS_WORD_DATA) || | |
383 | (data_arg.size == I2C_SMBUS_PROC_CALL)) | |
384 | datasize = sizeof(data_arg.data->word); | |
385 | else /* size == smbus block, i2c block, or block proc. call */ | |
386 | datasize = sizeof(data_arg.data->block); | |
387 | ||
388 | if ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
389 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
390 | (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) || | |
391 | (data_arg.read_write == I2C_SMBUS_WRITE)) { | |
392 | if (copy_from_user(&temp, data_arg.data, datasize)) | |
393 | return -EFAULT; | |
394 | } | |
395 | if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) { | |
396 | /* Convert old I2C block commands to the new | |
397 | convention. This preserves binary compatibility. */ | |
398 | data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA; | |
399 | if (data_arg.read_write == I2C_SMBUS_READ) | |
400 | temp.block[0] = I2C_SMBUS_BLOCK_MAX; | |
401 | } | |
402 | res = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
403 | data_arg.read_write, data_arg.command, data_arg.size, &temp); | |
404 | if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
405 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
406 | (data_arg.read_write == I2C_SMBUS_READ))) { | |
407 | if (copy_to_user(data_arg.data, &temp, datasize)) | |
408 | return -EFAULT; | |
409 | } | |
410 | return res; | |
411 | } | |
412 | ||
77e38bff | 413 | static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
dba7997a | 414 | { |
0be16c30 | 415 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
416 | unsigned long funcs; |
417 | ||
e8aafcb2 JD |
418 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
419 | cmd, arg); | |
1da177e4 | 420 | |
ae5624fc | 421 | switch (cmd) { |
1da177e4 LT |
422 | case I2C_SLAVE: |
423 | case I2C_SLAVE_FORCE: | |
438d6c2c | 424 | if ((arg > 0x3ff) || |
1da177e4 LT |
425 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) |
426 | return -EINVAL; | |
bd4217d8 | 427 | if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg)) |
1da177e4 | 428 | return -EBUSY; |
bd4217d8 | 429 | /* REVISIT: address could become busy later */ |
1da177e4 LT |
430 | client->addr = arg; |
431 | return 0; | |
432 | case I2C_TENBIT: | |
433 | if (arg) | |
434 | client->flags |= I2C_M_TEN; | |
435 | else | |
436 | client->flags &= ~I2C_M_TEN; | |
437 | return 0; | |
438 | case I2C_PEC: | |
9e685c84 JD |
439 | /* |
440 | * Setting the PEC flag here won't affect kernel drivers, | |
441 | * which will be using the i2c_client node registered with | |
442 | * the driver model core. Likewise, when that client has | |
443 | * the PEC flag already set, the i2c-dev driver won't see | |
444 | * (or use) this setting. | |
445 | */ | |
1da177e4 LT |
446 | if (arg) |
447 | client->flags |= I2C_CLIENT_PEC; | |
448 | else | |
449 | client->flags &= ~I2C_CLIENT_PEC; | |
450 | return 0; | |
451 | case I2C_FUNCS: | |
452 | funcs = i2c_get_functionality(client->adapter); | |
2c003e8e | 453 | return put_user(funcs, (unsigned long __user *)arg); |
1da177e4 LT |
454 | |
455 | case I2C_RDWR: | |
c57d3e7a | 456 | return i2cdev_ioctl_rdwr(client, arg); |
1da177e4 LT |
457 | |
458 | case I2C_SMBUS: | |
dba7997a | 459 | return i2cdev_ioctl_smbus(client, arg); |
1da177e4 | 460 | |
53be7959 DB |
461 | case I2C_RETRIES: |
462 | client->adapter->retries = arg; | |
463 | break; | |
464 | case I2C_TIMEOUT: | |
cd97f39b JD |
465 | /* For historical reasons, user-space sets the timeout |
466 | * value in units of 10 ms. | |
467 | */ | |
468 | client->adapter->timeout = msecs_to_jiffies(arg * 10); | |
53be7959 | 469 | break; |
1da177e4 | 470 | default: |
53be7959 DB |
471 | /* NOTE: returning a fault code here could cause trouble |
472 | * in buggy userspace code. Some old kernel bugs returned | |
473 | * zero in this case, and userspace code might accidentally | |
474 | * have depended on that bug. | |
475 | */ | |
476 | return -ENOTTY; | |
1da177e4 LT |
477 | } |
478 | return 0; | |
479 | } | |
480 | ||
481 | static int i2cdev_open(struct inode *inode, struct file *file) | |
482 | { | |
483 | unsigned int minor = iminor(inode); | |
484 | struct i2c_client *client; | |
485 | struct i2c_adapter *adap; | |
486 | struct i2c_dev *i2c_dev; | |
487 | ||
488 | i2c_dev = i2c_dev_get_by_minor(minor); | |
9669f541 VS |
489 | if (!i2c_dev) |
490 | return -ENODEV; | |
1da177e4 LT |
491 | |
492 | adap = i2c_get_adapter(i2c_dev->adap->nr); | |
9669f541 VS |
493 | if (!adap) |
494 | return -ENODEV; | |
1da177e4 | 495 | |
907135aa DB |
496 | /* This creates an anonymous i2c_client, which may later be |
497 | * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE. | |
498 | * | |
499 | * This client is ** NEVER REGISTERED ** with the driver model | |
500 | * or I2C core code!! It just holds private copies of addressing | |
501 | * information and maybe a PEC flag. | |
502 | */ | |
22f76e74 | 503 | client = kzalloc(sizeof(*client), GFP_KERNEL); |
1da177e4 LT |
504 | if (!client) { |
505 | i2c_put_adapter(adap); | |
9669f541 | 506 | return -ENOMEM; |
1da177e4 | 507 | } |
22f76e74 | 508 | snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); |
1da177e4 | 509 | |
1da177e4 LT |
510 | client->adapter = adap; |
511 | file->private_data = client; | |
512 | ||
9669f541 | 513 | return 0; |
1da177e4 LT |
514 | } |
515 | ||
516 | static int i2cdev_release(struct inode *inode, struct file *file) | |
517 | { | |
518 | struct i2c_client *client = file->private_data; | |
519 | ||
520 | i2c_put_adapter(client->adapter); | |
521 | kfree(client); | |
522 | file->private_data = NULL; | |
523 | ||
524 | return 0; | |
525 | } | |
526 | ||
2b8693c0 | 527 | static const struct file_operations i2cdev_fops = { |
1da177e4 LT |
528 | .owner = THIS_MODULE, |
529 | .llseek = no_llseek, | |
530 | .read = i2cdev_read, | |
531 | .write = i2cdev_write, | |
77e38bff | 532 | .unlocked_ioctl = i2cdev_ioctl, |
1da177e4 LT |
533 | .open = i2cdev_open, |
534 | .release = i2cdev_release, | |
535 | }; | |
536 | ||
907135aa DB |
537 | /* ------------------------------------------------------------------------- */ |
538 | ||
79472132 | 539 | static struct class *i2c_dev_class; |
1da177e4 | 540 | |
9ea3e941 | 541 | static int i2cdev_attach_adapter(struct device *dev, void *dummy) |
1da177e4 | 542 | { |
9ea3e941 | 543 | struct i2c_adapter *adap; |
1da177e4 | 544 | struct i2c_dev *i2c_dev; |
defcb46e | 545 | int res; |
1da177e4 | 546 | |
9ea3e941 JD |
547 | if (dev->type != &i2c_adapter_type) |
548 | return 0; | |
549 | adap = to_i2c_adapter(dev); | |
550 | ||
1da177e4 LT |
551 | i2c_dev = get_free_i2c_dev(adap); |
552 | if (IS_ERR(i2c_dev)) | |
553 | return PTR_ERR(i2c_dev); | |
554 | ||
1da177e4 | 555 | /* register this i2c device with the driver core */ |
a9b12619 GKH |
556 | i2c_dev->dev = device_create(i2c_dev_class, &adap->dev, |
557 | MKDEV(I2C_MAJOR, adap->nr), NULL, | |
558 | "i2c-%d", adap->nr); | |
3bacb36d AM |
559 | if (IS_ERR(i2c_dev->dev)) { |
560 | res = PTR_ERR(i2c_dev->dev); | |
1da177e4 | 561 | goto error; |
defcb46e | 562 | } |
b32d20dc JD |
563 | |
564 | pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", | |
565 | adap->name, adap->nr); | |
1da177e4 LT |
566 | return 0; |
567 | error: | |
568 | return_i2c_dev(i2c_dev); | |
defcb46e | 569 | return res; |
1da177e4 LT |
570 | } |
571 | ||
9ea3e941 | 572 | static int i2cdev_detach_adapter(struct device *dev, void *dummy) |
1da177e4 | 573 | { |
9ea3e941 | 574 | struct i2c_adapter *adap; |
1da177e4 LT |
575 | struct i2c_dev *i2c_dev; |
576 | ||
9ea3e941 JD |
577 | if (dev->type != &i2c_adapter_type) |
578 | return 0; | |
579 | adap = to_i2c_adapter(dev); | |
580 | ||
9455e4c9 | 581 | i2c_dev = i2c_dev_get_by_minor(adap->nr); |
b32d20dc JD |
582 | if (!i2c_dev) /* attach_adapter must have failed */ |
583 | return 0; | |
1da177e4 | 584 | |
1da177e4 | 585 | return_i2c_dev(i2c_dev); |
ac11d060 | 586 | device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 | 587 | |
b6d7b3d1 | 588 | pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
589 | return 0; |
590 | } | |
591 | ||
eff245c8 | 592 | static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action, |
9ea3e941 JD |
593 | void *data) |
594 | { | |
595 | struct device *dev = data; | |
596 | ||
597 | switch (action) { | |
598 | case BUS_NOTIFY_ADD_DEVICE: | |
599 | return i2cdev_attach_adapter(dev, NULL); | |
600 | case BUS_NOTIFY_DEL_DEVICE: | |
601 | return i2cdev_detach_adapter(dev, NULL); | |
602 | } | |
603 | ||
604 | return 0; | |
605 | } | |
606 | ||
607 | static struct notifier_block i2cdev_notifier = { | |
608 | .notifier_call = i2cdev_notifier_call, | |
1da177e4 LT |
609 | }; |
610 | ||
907135aa DB |
611 | /* ------------------------------------------------------------------------- */ |
612 | ||
613 | /* | |
614 | * module load/unload record keeping | |
615 | */ | |
616 | ||
1da177e4 LT |
617 | static int __init i2c_dev_init(void) |
618 | { | |
619 | int res; | |
620 | ||
621 | printk(KERN_INFO "i2c /dev entries driver\n"); | |
622 | ||
623 | res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops); | |
624 | if (res) | |
625 | goto out; | |
626 | ||
79472132 | 627 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
e74783ec SW |
628 | if (IS_ERR(i2c_dev_class)) { |
629 | res = PTR_ERR(i2c_dev_class); | |
1da177e4 | 630 | goto out_unreg_chrdev; |
e74783ec | 631 | } |
45f176ae | 632 | i2c_dev_class->dev_groups = i2c_groups; |
1da177e4 | 633 | |
9ea3e941 JD |
634 | /* Keep track of adapters which will be added or removed later */ |
635 | res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier); | |
1da177e4 LT |
636 | if (res) |
637 | goto out_unreg_class; | |
638 | ||
9ea3e941 JD |
639 | /* Bind to already existing adapters right away */ |
640 | i2c_for_each_dev(NULL, i2cdev_attach_adapter); | |
641 | ||
1da177e4 LT |
642 | return 0; |
643 | ||
644 | out_unreg_class: | |
79472132 | 645 | class_destroy(i2c_dev_class); |
1da177e4 LT |
646 | out_unreg_chrdev: |
647 | unregister_chrdev(I2C_MAJOR, "i2c"); | |
648 | out: | |
649 | printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); | |
650 | return res; | |
651 | } | |
652 | ||
653 | static void __exit i2c_dev_exit(void) | |
654 | { | |
9ea3e941 JD |
655 | bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier); |
656 | i2c_for_each_dev(NULL, i2cdev_detach_adapter); | |
79472132 | 657 | class_destroy(i2c_dev_class); |
ae5624fc | 658 | unregister_chrdev(I2C_MAJOR, "i2c"); |
1da177e4 LT |
659 | } |
660 | ||
661 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
662 | "Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
663 | MODULE_DESCRIPTION("I2C /dev entries driver"); | |
664 | MODULE_LICENSE("GPL"); | |
665 | ||
666 | module_init(i2c_dev_init); | |
667 | module_exit(i2c_dev_exit); |