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Commit | Line | Data |
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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 | 2 | /* |
438d6c2c | 3 | i2c-dev.c - i2c-bus driver, char device interface |
1da177e4 LT |
4 | |
5 | Copyright (C) 1995-97 Simon G. Vogl | |
6 | Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl> | |
7 | Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com> | |
8 | ||
1da177e4 LT |
9 | */ |
10 | ||
11 | /* Note that this is a complete rewrite of Simon Vogl's i2c-dev module. | |
12 | But I have used so much of his original code and ideas that it seems | |
13 | only fair to recognize him as co-author -- Frodo */ | |
14 | ||
15 | /* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */ | |
16 | ||
d6760b14 | 17 | #include <linux/cdev.h> |
f01adfab | 18 | #include <linux/compat.h> |
9ea3e941 | 19 | #include <linux/device.h> |
1da177e4 | 20 | #include <linux/fs.h> |
1da177e4 | 21 | #include <linux/i2c-dev.h> |
a8766073 WS |
22 | #include <linux/i2c.h> |
23 | #include <linux/init.h> | |
cd97f39b | 24 | #include <linux/jiffies.h> |
a8766073 WS |
25 | #include <linux/kernel.h> |
26 | #include <linux/list.h> | |
27 | #include <linux/module.h> | |
28 | #include <linux/notifier.h> | |
29 | #include <linux/slab.h> | |
ae5624fc | 30 | #include <linux/uaccess.h> |
1da177e4 | 31 | |
907135aa DB |
32 | /* |
33 | * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a | |
34 | * slave (i2c_client) with which messages will be exchanged. It's coupled | |
35 | * with a character special file which is accessed by user mode drivers. | |
36 | * | |
37 | * The list of i2c_dev structures is parallel to the i2c_adapter lists | |
9ea3e941 | 38 | * maintained by the driver model, and is updated using bus notifications. |
907135aa | 39 | */ |
1da177e4 | 40 | struct i2c_dev { |
f3b3aadb | 41 | struct list_head list; |
1da177e4 | 42 | struct i2c_adapter *adap; |
1413ef63 | 43 | struct device dev; |
d6760b14 | 44 | struct cdev cdev; |
1da177e4 | 45 | }; |
1da177e4 | 46 | |
8a6d508a | 47 | #define I2C_MINORS (MINORMASK + 1) |
f3b3aadb JD |
48 | static LIST_HEAD(i2c_dev_list); |
49 | static DEFINE_SPINLOCK(i2c_dev_list_lock); | |
1da177e4 LT |
50 | |
51 | static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) | |
52 | { | |
53 | struct i2c_dev *i2c_dev; | |
54 | ||
f3b3aadb JD |
55 | spin_lock(&i2c_dev_list_lock); |
56 | list_for_each_entry(i2c_dev, &i2c_dev_list, list) { | |
57 | if (i2c_dev->adap->nr == index) | |
58 | goto found; | |
59 | } | |
60 | i2c_dev = NULL; | |
61 | found: | |
62 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 LT |
63 | return i2c_dev; |
64 | } | |
65 | ||
1da177e4 LT |
66 | static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) |
67 | { | |
68 | struct i2c_dev *i2c_dev; | |
69 | ||
f3b3aadb JD |
70 | if (adap->nr >= I2C_MINORS) { |
71 | printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n", | |
72 | adap->nr); | |
73 | return ERR_PTR(-ENODEV); | |
74 | } | |
75 | ||
5263ebb5 | 76 | i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); |
1da177e4 LT |
77 | if (!i2c_dev) |
78 | return ERR_PTR(-ENOMEM); | |
9455e4c9 | 79 | i2c_dev->adap = adap; |
f3b3aadb JD |
80 | |
81 | spin_lock(&i2c_dev_list_lock); | |
82 | list_add_tail(&i2c_dev->list, &i2c_dev_list); | |
83 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 | 84 | return i2c_dev; |
1da177e4 LT |
85 | } |
86 | ||
1413ef63 | 87 | static void put_i2c_dev(struct i2c_dev *i2c_dev, bool del_cdev) |
1da177e4 | 88 | { |
f3b3aadb JD |
89 | spin_lock(&i2c_dev_list_lock); |
90 | list_del(&i2c_dev->list); | |
91 | spin_unlock(&i2c_dev_list_lock); | |
1413ef63 KH |
92 | if (del_cdev) |
93 | cdev_device_del(&i2c_dev->cdev, &i2c_dev->dev); | |
94 | put_device(&i2c_dev->dev); | |
1da177e4 LT |
95 | } |
96 | ||
45f176ae GR |
97 | static ssize_t name_show(struct device *dev, |
98 | struct device_attribute *attr, char *buf) | |
1da177e4 | 99 | { |
ac11d060 | 100 | struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt)); |
79472132 GKH |
101 | |
102 | if (!i2c_dev) | |
103 | return -ENODEV; | |
1da177e4 LT |
104 | return sprintf(buf, "%s\n", i2c_dev->adap->name); |
105 | } | |
45f176ae GR |
106 | static DEVICE_ATTR_RO(name); |
107 | ||
108 | static struct attribute *i2c_attrs[] = { | |
109 | &dev_attr_name.attr, | |
110 | NULL, | |
111 | }; | |
112 | ATTRIBUTE_GROUPS(i2c); | |
1da177e4 | 113 | |
907135aa DB |
114 | /* ------------------------------------------------------------------------- */ |
115 | ||
116 | /* | |
117 | * After opening an instance of this character special file, a file | |
118 | * descriptor starts out associated only with an i2c_adapter (and bus). | |
119 | * | |
120 | * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg | |
121 | * traffic to any devices on the bus used by that adapter. That's because | |
122 | * the i2c_msg vectors embed all the addressing information they need, and | |
123 | * are submitted directly to an i2c_adapter. However, SMBus-only adapters | |
124 | * don't support that interface. | |
125 | * | |
126 | * To use read()/write() system calls on that file descriptor, or to use | |
127 | * SMBus interfaces (and work with SMBus-only hosts!), you must first issue | |
128 | * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous | |
129 | * (never registered) i2c_client so it holds the addressing information | |
130 | * needed by those system calls and by this SMBus interface. | |
131 | */ | |
132 | ||
ae5624fc FH |
133 | static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count, |
134 | loff_t *offset) | |
1da177e4 LT |
135 | { |
136 | char *tmp; | |
137 | int ret; | |
138 | ||
0be16c30 | 139 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
140 | |
141 | if (count > 8192) | |
142 | count = 8192; | |
143 | ||
ae5624fc FH |
144 | tmp = kmalloc(count, GFP_KERNEL); |
145 | if (tmp == NULL) | |
1da177e4 LT |
146 | return -ENOMEM; |
147 | ||
2ce5b34f | 148 | pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n", |
496ad9aa | 149 | iminor(file_inode(file)), count); |
1da177e4 | 150 | |
ae5624fc | 151 | ret = i2c_master_recv(client, tmp, count); |
1da177e4 | 152 | if (ret >= 0) |
ae5624fc | 153 | ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret; |
1da177e4 LT |
154 | kfree(tmp); |
155 | return ret; | |
156 | } | |
157 | ||
ae5624fc FH |
158 | static ssize_t i2cdev_write(struct file *file, const char __user *buf, |
159 | size_t count, loff_t *offset) | |
1da177e4 LT |
160 | { |
161 | int ret; | |
162 | char *tmp; | |
0be16c30 | 163 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
164 | |
165 | if (count > 8192) | |
166 | count = 8192; | |
167 | ||
f1c2e33c JL |
168 | tmp = memdup_user(buf, count); |
169 | if (IS_ERR(tmp)) | |
170 | return PTR_ERR(tmp); | |
1da177e4 | 171 | |
2ce5b34f | 172 | pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n", |
496ad9aa | 173 | iminor(file_inode(file)), count); |
1da177e4 | 174 | |
ae5624fc | 175 | ret = i2c_master_send(client, tmp, count); |
1da177e4 LT |
176 | kfree(tmp); |
177 | return ret; | |
178 | } | |
179 | ||
9b766b81 DB |
180 | static int i2cdev_check(struct device *dev, void *addrp) |
181 | { | |
182 | struct i2c_client *client = i2c_verify_client(dev); | |
183 | ||
184 | if (!client || client->addr != *(unsigned int *)addrp) | |
185 | return 0; | |
186 | ||
187 | return dev->driver ? -EBUSY : 0; | |
188 | } | |
189 | ||
0826374b ML |
190 | /* walk up mux tree */ |
191 | static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
192 | { | |
97cc4d49 | 193 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
194 | int result; |
195 | ||
196 | result = device_for_each_child(&adapter->dev, &addr, i2cdev_check); | |
97cc4d49 JD |
197 | if (!result && parent) |
198 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
199 | |
200 | return result; | |
201 | } | |
202 | ||
203 | /* recurse down mux tree */ | |
204 | static int i2cdev_check_mux_children(struct device *dev, void *addrp) | |
205 | { | |
206 | int result; | |
207 | ||
208 | if (dev->type == &i2c_adapter_type) | |
209 | result = device_for_each_child(dev, addrp, | |
210 | i2cdev_check_mux_children); | |
211 | else | |
212 | result = i2cdev_check(dev, addrp); | |
213 | ||
214 | return result; | |
215 | } | |
216 | ||
bd4217d8 JD |
217 | /* This address checking function differs from the one in i2c-core |
218 | in that it considers an address with a registered device, but no | |
9b766b81 | 219 | driver bound to it, as NOT busy. */ |
bd4217d8 JD |
220 | static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) |
221 | { | |
97cc4d49 | 222 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
223 | int result = 0; |
224 | ||
97cc4d49 JD |
225 | if (parent) |
226 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
227 | |
228 | if (!result) | |
229 | result = device_for_each_child(&adapter->dev, &addr, | |
230 | i2cdev_check_mux_children); | |
231 | ||
232 | return result; | |
bd4217d8 JD |
233 | } |
234 | ||
c57d3e7a | 235 | static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client, |
7d5cb456 | 236 | unsigned nmsgs, struct i2c_msg *msgs) |
1da177e4 | 237 | { |
1da177e4 | 238 | u8 __user **data_ptrs; |
dba7997a JD |
239 | int i, res; |
240 | ||
6da2ec56 | 241 | data_ptrs = kmalloc_array(nmsgs, sizeof(u8 __user *), GFP_KERNEL); |
dba7997a | 242 | if (data_ptrs == NULL) { |
7d5cb456 | 243 | kfree(msgs); |
dba7997a JD |
244 | return -ENOMEM; |
245 | } | |
246 | ||
247 | res = 0; | |
7d5cb456 | 248 | for (i = 0; i < nmsgs; i++) { |
838bfa60 | 249 | /* Limit the size of the message to a sane amount */ |
7d5cb456 | 250 | if (msgs[i].len > 8192) { |
dba7997a JD |
251 | res = -EINVAL; |
252 | break; | |
253 | } | |
838bfa60 | 254 | |
7d5cb456 AV |
255 | data_ptrs[i] = (u8 __user *)msgs[i].buf; |
256 | msgs[i].buf = memdup_user(data_ptrs[i], msgs[i].len); | |
257 | if (IS_ERR(msgs[i].buf)) { | |
258 | res = PTR_ERR(msgs[i].buf); | |
dba7997a JD |
259 | break; |
260 | } | |
978336d4 WS |
261 | /* memdup_user allocates with GFP_KERNEL, so DMA is ok */ |
262 | msgs[i].flags |= I2C_M_DMA_SAFE; | |
838bfa60 JD |
263 | |
264 | /* | |
265 | * If the message length is received from the slave (similar | |
266 | * to SMBus block read), we must ensure that the buffer will | |
267 | * be large enough to cope with a message length of | |
268 | * I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus | |
269 | * drivers allow. The first byte in the buffer must be | |
270 | * pre-filled with the number of extra bytes, which must be | |
271 | * at least one to hold the message length, but can be | |
272 | * greater (for example to account for a checksum byte at | |
273 | * the end of the message.) | |
274 | */ | |
7d5cb456 AV |
275 | if (msgs[i].flags & I2C_M_RECV_LEN) { |
276 | if (!(msgs[i].flags & I2C_M_RD) || | |
23a27722 | 277 | msgs[i].len < 1 || msgs[i].buf[0] < 1 || |
7d5cb456 | 278 | msgs[i].len < msgs[i].buf[0] + |
838bfa60 | 279 | I2C_SMBUS_BLOCK_MAX) { |
a0692f0e | 280 | i++; |
838bfa60 JD |
281 | res = -EINVAL; |
282 | break; | |
283 | } | |
284 | ||
7d5cb456 | 285 | msgs[i].len = msgs[i].buf[0]; |
838bfa60 | 286 | } |
dba7997a JD |
287 | } |
288 | if (res < 0) { | |
289 | int j; | |
290 | for (j = 0; j < i; ++j) | |
7d5cb456 | 291 | kfree(msgs[j].buf); |
dba7997a | 292 | kfree(data_ptrs); |
7d5cb456 | 293 | kfree(msgs); |
dba7997a JD |
294 | return res; |
295 | } | |
296 | ||
7d5cb456 | 297 | res = i2c_transfer(client->adapter, msgs, nmsgs); |
dba7997a | 298 | while (i-- > 0) { |
7d5cb456 AV |
299 | if (res >= 0 && (msgs[i].flags & I2C_M_RD)) { |
300 | if (copy_to_user(data_ptrs[i], msgs[i].buf, | |
301 | msgs[i].len)) | |
dba7997a JD |
302 | res = -EFAULT; |
303 | } | |
7d5cb456 | 304 | kfree(msgs[i].buf); |
dba7997a JD |
305 | } |
306 | kfree(data_ptrs); | |
7d5cb456 | 307 | kfree(msgs); |
dba7997a JD |
308 | return res; |
309 | } | |
310 | ||
311 | static noinline int i2cdev_ioctl_smbus(struct i2c_client *client, | |
7d5cb456 AV |
312 | u8 read_write, u8 command, u32 size, |
313 | union i2c_smbus_data __user *data) | |
dba7997a | 314 | { |
30f939fe | 315 | union i2c_smbus_data temp = {}; |
dba7997a JD |
316 | int datasize, res; |
317 | ||
7d5cb456 AV |
318 | if ((size != I2C_SMBUS_BYTE) && |
319 | (size != I2C_SMBUS_QUICK) && | |
320 | (size != I2C_SMBUS_BYTE_DATA) && | |
321 | (size != I2C_SMBUS_WORD_DATA) && | |
322 | (size != I2C_SMBUS_PROC_CALL) && | |
323 | (size != I2C_SMBUS_BLOCK_DATA) && | |
324 | (size != I2C_SMBUS_I2C_BLOCK_BROKEN) && | |
325 | (size != I2C_SMBUS_I2C_BLOCK_DATA) && | |
326 | (size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
dba7997a JD |
327 | dev_dbg(&client->adapter->dev, |
328 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
7d5cb456 | 329 | size); |
dba7997a JD |
330 | return -EINVAL; |
331 | } | |
332 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, | |
333 | so the check is valid if size==I2C_SMBUS_QUICK too. */ | |
7d5cb456 AV |
334 | if ((read_write != I2C_SMBUS_READ) && |
335 | (read_write != I2C_SMBUS_WRITE)) { | |
dba7997a JD |
336 | dev_dbg(&client->adapter->dev, |
337 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", | |
7d5cb456 | 338 | read_write); |
dba7997a JD |
339 | return -EINVAL; |
340 | } | |
341 | ||
342 | /* Note that command values are always valid! */ | |
343 | ||
7d5cb456 AV |
344 | if ((size == I2C_SMBUS_QUICK) || |
345 | ((size == I2C_SMBUS_BYTE) && | |
346 | (read_write == I2C_SMBUS_WRITE))) | |
dba7997a JD |
347 | /* These are special: we do not use data */ |
348 | return i2c_smbus_xfer(client->adapter, client->addr, | |
7d5cb456 AV |
349 | client->flags, read_write, |
350 | command, size, NULL); | |
dba7997a | 351 | |
7d5cb456 | 352 | if (data == NULL) { |
dba7997a JD |
353 | dev_dbg(&client->adapter->dev, |
354 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
355 | return -EINVAL; | |
356 | } | |
357 | ||
7d5cb456 AV |
358 | if ((size == I2C_SMBUS_BYTE_DATA) || |
359 | (size == I2C_SMBUS_BYTE)) | |
360 | datasize = sizeof(data->byte); | |
361 | else if ((size == I2C_SMBUS_WORD_DATA) || | |
362 | (size == I2C_SMBUS_PROC_CALL)) | |
363 | datasize = sizeof(data->word); | |
dba7997a | 364 | else /* size == smbus block, i2c block, or block proc. call */ |
7d5cb456 | 365 | datasize = sizeof(data->block); |
dba7997a | 366 | |
7d5cb456 AV |
367 | if ((size == I2C_SMBUS_PROC_CALL) || |
368 | (size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
369 | (size == I2C_SMBUS_I2C_BLOCK_DATA) || | |
370 | (read_write == I2C_SMBUS_WRITE)) { | |
371 | if (copy_from_user(&temp, data, datasize)) | |
dba7997a JD |
372 | return -EFAULT; |
373 | } | |
7d5cb456 | 374 | if (size == I2C_SMBUS_I2C_BLOCK_BROKEN) { |
dba7997a JD |
375 | /* Convert old I2C block commands to the new |
376 | convention. This preserves binary compatibility. */ | |
7d5cb456 AV |
377 | size = I2C_SMBUS_I2C_BLOCK_DATA; |
378 | if (read_write == I2C_SMBUS_READ) | |
dba7997a JD |
379 | temp.block[0] = I2C_SMBUS_BLOCK_MAX; |
380 | } | |
381 | res = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
7d5cb456 AV |
382 | read_write, command, size, &temp); |
383 | if (!res && ((size == I2C_SMBUS_PROC_CALL) || | |
384 | (size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
385 | (read_write == I2C_SMBUS_READ))) { | |
386 | if (copy_to_user(data, &temp, datasize)) | |
dba7997a JD |
387 | return -EFAULT; |
388 | } | |
389 | return res; | |
390 | } | |
391 | ||
77e38bff | 392 | static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
dba7997a | 393 | { |
0be16c30 | 394 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
395 | unsigned long funcs; |
396 | ||
e8aafcb2 JD |
397 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
398 | cmd, arg); | |
1da177e4 | 399 | |
ae5624fc | 400 | switch (cmd) { |
1da177e4 LT |
401 | case I2C_SLAVE: |
402 | case I2C_SLAVE_FORCE: | |
438d6c2c | 403 | if ((arg > 0x3ff) || |
1da177e4 LT |
404 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) |
405 | return -EINVAL; | |
bd4217d8 | 406 | if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg)) |
1da177e4 | 407 | return -EBUSY; |
bd4217d8 | 408 | /* REVISIT: address could become busy later */ |
1da177e4 LT |
409 | client->addr = arg; |
410 | return 0; | |
411 | case I2C_TENBIT: | |
412 | if (arg) | |
413 | client->flags |= I2C_M_TEN; | |
414 | else | |
415 | client->flags &= ~I2C_M_TEN; | |
416 | return 0; | |
417 | case I2C_PEC: | |
9e685c84 JD |
418 | /* |
419 | * Setting the PEC flag here won't affect kernel drivers, | |
420 | * which will be using the i2c_client node registered with | |
421 | * the driver model core. Likewise, when that client has | |
422 | * the PEC flag already set, the i2c-dev driver won't see | |
423 | * (or use) this setting. | |
424 | */ | |
1da177e4 LT |
425 | if (arg) |
426 | client->flags |= I2C_CLIENT_PEC; | |
427 | else | |
428 | client->flags &= ~I2C_CLIENT_PEC; | |
429 | return 0; | |
430 | case I2C_FUNCS: | |
431 | funcs = i2c_get_functionality(client->adapter); | |
2c003e8e | 432 | return put_user(funcs, (unsigned long __user *)arg); |
1da177e4 | 433 | |
7d5cb456 AV |
434 | case I2C_RDWR: { |
435 | struct i2c_rdwr_ioctl_data rdwr_arg; | |
436 | struct i2c_msg *rdwr_pa; | |
437 | ||
438 | if (copy_from_user(&rdwr_arg, | |
439 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
440 | sizeof(rdwr_arg))) | |
441 | return -EFAULT; | |
442 | ||
443 | /* Put an arbitrary limit on the number of messages that can | |
444 | * be sent at once */ | |
445 | if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) | |
446 | return -EINVAL; | |
1da177e4 | 447 | |
7d5cb456 AV |
448 | rdwr_pa = memdup_user(rdwr_arg.msgs, |
449 | rdwr_arg.nmsgs * sizeof(struct i2c_msg)); | |
450 | if (IS_ERR(rdwr_pa)) | |
451 | return PTR_ERR(rdwr_pa); | |
452 | ||
453 | return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa); | |
454 | } | |
1da177e4 | 455 | |
7d5cb456 AV |
456 | case I2C_SMBUS: { |
457 | struct i2c_smbus_ioctl_data data_arg; | |
458 | if (copy_from_user(&data_arg, | |
459 | (struct i2c_smbus_ioctl_data __user *) arg, | |
460 | sizeof(struct i2c_smbus_ioctl_data))) | |
461 | return -EFAULT; | |
462 | return i2cdev_ioctl_smbus(client, data_arg.read_write, | |
463 | data_arg.command, | |
464 | data_arg.size, | |
465 | data_arg.data); | |
466 | } | |
53be7959 | 467 | case I2C_RETRIES: |
6ebec961 YZ |
468 | if (arg > INT_MAX) |
469 | return -EINVAL; | |
470 | ||
53be7959 DB |
471 | client->adapter->retries = arg; |
472 | break; | |
473 | case I2C_TIMEOUT: | |
6ebec961 YZ |
474 | if (arg > INT_MAX) |
475 | return -EINVAL; | |
476 | ||
cd97f39b JD |
477 | /* For historical reasons, user-space sets the timeout |
478 | * value in units of 10 ms. | |
479 | */ | |
480 | client->adapter->timeout = msecs_to_jiffies(arg * 10); | |
53be7959 | 481 | break; |
1da177e4 | 482 | default: |
53be7959 DB |
483 | /* NOTE: returning a fault code here could cause trouble |
484 | * in buggy userspace code. Some old kernel bugs returned | |
485 | * zero in this case, and userspace code might accidentally | |
486 | * have depended on that bug. | |
487 | */ | |
488 | return -ENOTTY; | |
1da177e4 LT |
489 | } |
490 | return 0; | |
491 | } | |
492 | ||
7d5cb456 AV |
493 | #ifdef CONFIG_COMPAT |
494 | ||
495 | struct i2c_smbus_ioctl_data32 { | |
496 | u8 read_write; | |
497 | u8 command; | |
498 | u32 size; | |
499 | compat_caddr_t data; /* union i2c_smbus_data *data */ | |
500 | }; | |
501 | ||
502 | struct i2c_msg32 { | |
503 | u16 addr; | |
504 | u16 flags; | |
505 | u16 len; | |
506 | compat_caddr_t buf; | |
507 | }; | |
508 | ||
509 | struct i2c_rdwr_ioctl_data32 { | |
510 | compat_caddr_t msgs; /* struct i2c_msg __user *msgs */ | |
511 | u32 nmsgs; | |
512 | }; | |
513 | ||
514 | static long compat_i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
515 | { | |
516 | struct i2c_client *client = file->private_data; | |
517 | unsigned long funcs; | |
518 | switch (cmd) { | |
519 | case I2C_FUNCS: | |
520 | funcs = i2c_get_functionality(client->adapter); | |
521 | return put_user(funcs, (compat_ulong_t __user *)arg); | |
522 | case I2C_RDWR: { | |
523 | struct i2c_rdwr_ioctl_data32 rdwr_arg; | |
524 | struct i2c_msg32 *p; | |
525 | struct i2c_msg *rdwr_pa; | |
526 | int i; | |
527 | ||
528 | if (copy_from_user(&rdwr_arg, | |
529 | (struct i2c_rdwr_ioctl_data32 __user *)arg, | |
530 | sizeof(rdwr_arg))) | |
531 | return -EFAULT; | |
532 | ||
533 | if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) | |
534 | return -EINVAL; | |
535 | ||
536 | rdwr_pa = kmalloc_array(rdwr_arg.nmsgs, sizeof(struct i2c_msg), | |
537 | GFP_KERNEL); | |
538 | if (!rdwr_pa) | |
539 | return -ENOMEM; | |
540 | ||
541 | p = compat_ptr(rdwr_arg.msgs); | |
542 | for (i = 0; i < rdwr_arg.nmsgs; i++) { | |
543 | struct i2c_msg32 umsg; | |
544 | if (copy_from_user(&umsg, p + i, sizeof(umsg))) { | |
545 | kfree(rdwr_pa); | |
546 | return -EFAULT; | |
547 | } | |
548 | rdwr_pa[i] = (struct i2c_msg) { | |
549 | .addr = umsg.addr, | |
550 | .flags = umsg.flags, | |
551 | .len = umsg.len, | |
552 | .buf = compat_ptr(umsg.buf) | |
553 | }; | |
554 | } | |
555 | ||
556 | return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa); | |
557 | } | |
558 | case I2C_SMBUS: { | |
559 | struct i2c_smbus_ioctl_data32 data32; | |
560 | if (copy_from_user(&data32, | |
561 | (void __user *) arg, | |
562 | sizeof(data32))) | |
563 | return -EFAULT; | |
564 | return i2cdev_ioctl_smbus(client, data32.read_write, | |
565 | data32.command, | |
566 | data32.size, | |
567 | compat_ptr(data32.data)); | |
568 | } | |
569 | default: | |
570 | return i2cdev_ioctl(file, cmd, arg); | |
571 | } | |
572 | } | |
573 | #else | |
574 | #define compat_i2cdev_ioctl NULL | |
575 | #endif | |
576 | ||
1da177e4 LT |
577 | static int i2cdev_open(struct inode *inode, struct file *file) |
578 | { | |
579 | unsigned int minor = iminor(inode); | |
580 | struct i2c_client *client; | |
581 | struct i2c_adapter *adap; | |
1da177e4 | 582 | |
5136ed4f | 583 | adap = i2c_get_adapter(minor); |
9669f541 VS |
584 | if (!adap) |
585 | return -ENODEV; | |
1da177e4 | 586 | |
907135aa DB |
587 | /* This creates an anonymous i2c_client, which may later be |
588 | * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE. | |
589 | * | |
590 | * This client is ** NEVER REGISTERED ** with the driver model | |
591 | * or I2C core code!! It just holds private copies of addressing | |
592 | * information and maybe a PEC flag. | |
593 | */ | |
22f76e74 | 594 | client = kzalloc(sizeof(*client), GFP_KERNEL); |
1da177e4 LT |
595 | if (!client) { |
596 | i2c_put_adapter(adap); | |
9669f541 | 597 | return -ENOMEM; |
1da177e4 | 598 | } |
22f76e74 | 599 | snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); |
1da177e4 | 600 | |
1da177e4 LT |
601 | client->adapter = adap; |
602 | file->private_data = client; | |
603 | ||
9669f541 | 604 | return 0; |
1da177e4 LT |
605 | } |
606 | ||
607 | static int i2cdev_release(struct inode *inode, struct file *file) | |
608 | { | |
609 | struct i2c_client *client = file->private_data; | |
610 | ||
611 | i2c_put_adapter(client->adapter); | |
612 | kfree(client); | |
613 | file->private_data = NULL; | |
614 | ||
615 | return 0; | |
616 | } | |
617 | ||
2b8693c0 | 618 | static const struct file_operations i2cdev_fops = { |
1da177e4 LT |
619 | .owner = THIS_MODULE, |
620 | .llseek = no_llseek, | |
621 | .read = i2cdev_read, | |
622 | .write = i2cdev_write, | |
77e38bff | 623 | .unlocked_ioctl = i2cdev_ioctl, |
7d5cb456 | 624 | .compat_ioctl = compat_i2cdev_ioctl, |
1da177e4 LT |
625 | .open = i2cdev_open, |
626 | .release = i2cdev_release, | |
627 | }; | |
628 | ||
907135aa DB |
629 | /* ------------------------------------------------------------------------- */ |
630 | ||
79472132 | 631 | static struct class *i2c_dev_class; |
1da177e4 | 632 | |
1413ef63 KH |
633 | static void i2cdev_dev_release(struct device *dev) |
634 | { | |
635 | struct i2c_dev *i2c_dev; | |
636 | ||
637 | i2c_dev = container_of(dev, struct i2c_dev, dev); | |
638 | kfree(i2c_dev); | |
639 | } | |
640 | ||
9ea3e941 | 641 | static int i2cdev_attach_adapter(struct device *dev, void *dummy) |
1da177e4 | 642 | { |
9ea3e941 | 643 | struct i2c_adapter *adap; |
1da177e4 | 644 | struct i2c_dev *i2c_dev; |
defcb46e | 645 | int res; |
1da177e4 | 646 | |
9ea3e941 JD |
647 | if (dev->type != &i2c_adapter_type) |
648 | return 0; | |
649 | adap = to_i2c_adapter(dev); | |
650 | ||
1da177e4 LT |
651 | i2c_dev = get_free_i2c_dev(adap); |
652 | if (IS_ERR(i2c_dev)) | |
653 | return PTR_ERR(i2c_dev); | |
654 | ||
d6760b14 EN |
655 | cdev_init(&i2c_dev->cdev, &i2cdev_fops); |
656 | i2c_dev->cdev.owner = THIS_MODULE; | |
1413ef63 KH |
657 | |
658 | device_initialize(&i2c_dev->dev); | |
659 | i2c_dev->dev.devt = MKDEV(I2C_MAJOR, adap->nr); | |
660 | i2c_dev->dev.class = i2c_dev_class; | |
661 | i2c_dev->dev.parent = &adap->dev; | |
662 | i2c_dev->dev.release = i2cdev_dev_release; | |
663 | dev_set_name(&i2c_dev->dev, "i2c-%d", adap->nr); | |
664 | ||
665 | res = cdev_device_add(&i2c_dev->cdev, &i2c_dev->dev); | |
666 | if (res) { | |
667 | put_i2c_dev(i2c_dev, false); | |
668 | return res; | |
defcb46e | 669 | } |
b32d20dc JD |
670 | |
671 | pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", | |
672 | adap->name, adap->nr); | |
1da177e4 | 673 | return 0; |
1da177e4 LT |
674 | } |
675 | ||
9ea3e941 | 676 | static int i2cdev_detach_adapter(struct device *dev, void *dummy) |
1da177e4 | 677 | { |
9ea3e941 | 678 | struct i2c_adapter *adap; |
1da177e4 LT |
679 | struct i2c_dev *i2c_dev; |
680 | ||
9ea3e941 JD |
681 | if (dev->type != &i2c_adapter_type) |
682 | return 0; | |
683 | adap = to_i2c_adapter(dev); | |
684 | ||
9455e4c9 | 685 | i2c_dev = i2c_dev_get_by_minor(adap->nr); |
b32d20dc JD |
686 | if (!i2c_dev) /* attach_adapter must have failed */ |
687 | return 0; | |
1da177e4 | 688 | |
1413ef63 | 689 | put_i2c_dev(i2c_dev, true); |
1da177e4 | 690 | |
b6d7b3d1 | 691 | pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
692 | return 0; |
693 | } | |
694 | ||
eff245c8 | 695 | static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action, |
9ea3e941 JD |
696 | void *data) |
697 | { | |
698 | struct device *dev = data; | |
699 | ||
700 | switch (action) { | |
701 | case BUS_NOTIFY_ADD_DEVICE: | |
702 | return i2cdev_attach_adapter(dev, NULL); | |
703 | case BUS_NOTIFY_DEL_DEVICE: | |
704 | return i2cdev_detach_adapter(dev, NULL); | |
705 | } | |
706 | ||
707 | return 0; | |
708 | } | |
709 | ||
710 | static struct notifier_block i2cdev_notifier = { | |
711 | .notifier_call = i2cdev_notifier_call, | |
1da177e4 LT |
712 | }; |
713 | ||
907135aa DB |
714 | /* ------------------------------------------------------------------------- */ |
715 | ||
716 | /* | |
717 | * module load/unload record keeping | |
718 | */ | |
719 | ||
1da177e4 LT |
720 | static int __init i2c_dev_init(void) |
721 | { | |
722 | int res; | |
723 | ||
724 | printk(KERN_INFO "i2c /dev entries driver\n"); | |
725 | ||
d6760b14 | 726 | res = register_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS, "i2c"); |
1da177e4 LT |
727 | if (res) |
728 | goto out; | |
729 | ||
79472132 | 730 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
e74783ec SW |
731 | if (IS_ERR(i2c_dev_class)) { |
732 | res = PTR_ERR(i2c_dev_class); | |
1da177e4 | 733 | goto out_unreg_chrdev; |
e74783ec | 734 | } |
45f176ae | 735 | i2c_dev_class->dev_groups = i2c_groups; |
1da177e4 | 736 | |
9ea3e941 JD |
737 | /* Keep track of adapters which will be added or removed later */ |
738 | res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier); | |
1da177e4 LT |
739 | if (res) |
740 | goto out_unreg_class; | |
741 | ||
9ea3e941 JD |
742 | /* Bind to already existing adapters right away */ |
743 | i2c_for_each_dev(NULL, i2cdev_attach_adapter); | |
744 | ||
1da177e4 LT |
745 | return 0; |
746 | ||
747 | out_unreg_class: | |
79472132 | 748 | class_destroy(i2c_dev_class); |
1da177e4 | 749 | out_unreg_chrdev: |
d6760b14 | 750 | unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS); |
1da177e4 LT |
751 | out: |
752 | printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); | |
753 | return res; | |
754 | } | |
755 | ||
756 | static void __exit i2c_dev_exit(void) | |
757 | { | |
9ea3e941 JD |
758 | bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier); |
759 | i2c_for_each_dev(NULL, i2cdev_detach_adapter); | |
79472132 | 760 | class_destroy(i2c_dev_class); |
d6760b14 | 761 | unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS); |
1da177e4 LT |
762 | } |
763 | ||
f80531c8 JN |
764 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>"); |
765 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
1da177e4 LT |
766 | MODULE_DESCRIPTION("I2C /dev entries driver"); |
767 | MODULE_LICENSE("GPL"); | |
768 | ||
769 | module_init(i2c_dev_init); | |
770 | module_exit(i2c_dev_exit); |