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 | ||
295e0e7b AS |
17 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
18 | ||
d6760b14 | 19 | #include <linux/cdev.h> |
f01adfab | 20 | #include <linux/compat.h> |
9ea3e941 | 21 | #include <linux/device.h> |
1da177e4 | 22 | #include <linux/fs.h> |
1da177e4 | 23 | #include <linux/i2c-dev.h> |
a8766073 WS |
24 | #include <linux/i2c.h> |
25 | #include <linux/init.h> | |
cd97f39b | 26 | #include <linux/jiffies.h> |
a8766073 WS |
27 | #include <linux/kernel.h> |
28 | #include <linux/list.h> | |
29 | #include <linux/module.h> | |
30 | #include <linux/notifier.h> | |
31 | #include <linux/slab.h> | |
ae5624fc | 32 | #include <linux/uaccess.h> |
1da177e4 | 33 | |
907135aa DB |
34 | /* |
35 | * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a | |
36 | * slave (i2c_client) with which messages will be exchanged. It's coupled | |
37 | * with a character special file which is accessed by user mode drivers. | |
38 | * | |
39 | * The list of i2c_dev structures is parallel to the i2c_adapter lists | |
9ea3e941 | 40 | * maintained by the driver model, and is updated using bus notifications. |
907135aa | 41 | */ |
1da177e4 | 42 | struct i2c_dev { |
f3b3aadb | 43 | struct list_head list; |
1da177e4 | 44 | struct i2c_adapter *adap; |
1413ef63 | 45 | struct device dev; |
d6760b14 | 46 | struct cdev cdev; |
1da177e4 | 47 | }; |
1da177e4 | 48 | |
8a6d508a | 49 | #define I2C_MINORS (MINORMASK + 1) |
f3b3aadb JD |
50 | static LIST_HEAD(i2c_dev_list); |
51 | static DEFINE_SPINLOCK(i2c_dev_list_lock); | |
1da177e4 LT |
52 | |
53 | static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) | |
54 | { | |
55 | struct i2c_dev *i2c_dev; | |
56 | ||
f3b3aadb JD |
57 | spin_lock(&i2c_dev_list_lock); |
58 | list_for_each_entry(i2c_dev, &i2c_dev_list, list) { | |
59 | if (i2c_dev->adap->nr == index) | |
60 | goto found; | |
61 | } | |
62 | i2c_dev = NULL; | |
63 | found: | |
64 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 LT |
65 | return i2c_dev; |
66 | } | |
67 | ||
1da177e4 LT |
68 | static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) |
69 | { | |
70 | struct i2c_dev *i2c_dev; | |
71 | ||
f3b3aadb | 72 | if (adap->nr >= I2C_MINORS) { |
295e0e7b | 73 | pr_err("Out of device minors (%d)\n", adap->nr); |
f3b3aadb JD |
74 | return ERR_PTR(-ENODEV); |
75 | } | |
76 | ||
5263ebb5 | 77 | i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); |
1da177e4 LT |
78 | if (!i2c_dev) |
79 | return ERR_PTR(-ENOMEM); | |
9455e4c9 | 80 | i2c_dev->adap = adap; |
f3b3aadb JD |
81 | |
82 | spin_lock(&i2c_dev_list_lock); | |
83 | list_add_tail(&i2c_dev->list, &i2c_dev_list); | |
84 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 | 85 | return i2c_dev; |
1da177e4 LT |
86 | } |
87 | ||
1413ef63 | 88 | static void put_i2c_dev(struct i2c_dev *i2c_dev, bool del_cdev) |
1da177e4 | 89 | { |
f3b3aadb JD |
90 | spin_lock(&i2c_dev_list_lock); |
91 | list_del(&i2c_dev->list); | |
92 | spin_unlock(&i2c_dev_list_lock); | |
1413ef63 KH |
93 | if (del_cdev) |
94 | cdev_device_del(&i2c_dev->cdev, &i2c_dev->dev); | |
95 | put_device(&i2c_dev->dev); | |
1da177e4 LT |
96 | } |
97 | ||
45f176ae GR |
98 | static ssize_t name_show(struct device *dev, |
99 | struct device_attribute *attr, char *buf) | |
1da177e4 | 100 | { |
ac11d060 | 101 | struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt)); |
79472132 GKH |
102 | |
103 | if (!i2c_dev) | |
104 | return -ENODEV; | |
1da177e4 LT |
105 | return sprintf(buf, "%s\n", i2c_dev->adap->name); |
106 | } | |
45f176ae GR |
107 | static DEVICE_ATTR_RO(name); |
108 | ||
109 | static struct attribute *i2c_attrs[] = { | |
110 | &dev_attr_name.attr, | |
111 | NULL, | |
112 | }; | |
113 | ATTRIBUTE_GROUPS(i2c); | |
1da177e4 | 114 | |
907135aa DB |
115 | /* ------------------------------------------------------------------------- */ |
116 | ||
117 | /* | |
118 | * After opening an instance of this character special file, a file | |
119 | * descriptor starts out associated only with an i2c_adapter (and bus). | |
120 | * | |
121 | * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg | |
122 | * traffic to any devices on the bus used by that adapter. That's because | |
123 | * the i2c_msg vectors embed all the addressing information they need, and | |
124 | * are submitted directly to an i2c_adapter. However, SMBus-only adapters | |
125 | * don't support that interface. | |
126 | * | |
127 | * To use read()/write() system calls on that file descriptor, or to use | |
128 | * SMBus interfaces (and work with SMBus-only hosts!), you must first issue | |
129 | * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous | |
130 | * (never registered) i2c_client so it holds the addressing information | |
131 | * needed by those system calls and by this SMBus interface. | |
132 | */ | |
133 | ||
ae5624fc FH |
134 | static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count, |
135 | loff_t *offset) | |
1da177e4 LT |
136 | { |
137 | char *tmp; | |
138 | int ret; | |
139 | ||
0be16c30 | 140 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
141 | |
142 | if (count > 8192) | |
143 | count = 8192; | |
144 | ||
ae5624fc FH |
145 | tmp = kmalloc(count, GFP_KERNEL); |
146 | if (tmp == NULL) | |
1da177e4 LT |
147 | return -ENOMEM; |
148 | ||
295e0e7b | 149 | pr_debug("i2c-%d reading %zu bytes.\n", 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 | |
295e0e7b | 172 | pr_debug("i2c-%d writing %zu bytes.\n", iminor(file_inode(file)), count); |
1da177e4 | 173 | |
ae5624fc | 174 | ret = i2c_master_send(client, tmp, count); |
1da177e4 LT |
175 | kfree(tmp); |
176 | return ret; | |
177 | } | |
178 | ||
9b766b81 DB |
179 | static int i2cdev_check(struct device *dev, void *addrp) |
180 | { | |
181 | struct i2c_client *client = i2c_verify_client(dev); | |
182 | ||
183 | if (!client || client->addr != *(unsigned int *)addrp) | |
184 | return 0; | |
185 | ||
186 | return dev->driver ? -EBUSY : 0; | |
187 | } | |
188 | ||
0826374b ML |
189 | /* walk up mux tree */ |
190 | static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
191 | { | |
97cc4d49 | 192 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
193 | int result; |
194 | ||
195 | result = device_for_each_child(&adapter->dev, &addr, i2cdev_check); | |
97cc4d49 JD |
196 | if (!result && parent) |
197 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
198 | |
199 | return result; | |
200 | } | |
201 | ||
202 | /* recurse down mux tree */ | |
203 | static int i2cdev_check_mux_children(struct device *dev, void *addrp) | |
204 | { | |
205 | int result; | |
206 | ||
207 | if (dev->type == &i2c_adapter_type) | |
208 | result = device_for_each_child(dev, addrp, | |
209 | i2cdev_check_mux_children); | |
210 | else | |
211 | result = i2cdev_check(dev, addrp); | |
212 | ||
213 | return result; | |
214 | } | |
215 | ||
bd4217d8 JD |
216 | /* This address checking function differs from the one in i2c-core |
217 | in that it considers an address with a registered device, but no | |
9b766b81 | 218 | driver bound to it, as NOT busy. */ |
bd4217d8 JD |
219 | static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) |
220 | { | |
97cc4d49 | 221 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
222 | int result = 0; |
223 | ||
97cc4d49 JD |
224 | if (parent) |
225 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
226 | |
227 | if (!result) | |
228 | result = device_for_each_child(&adapter->dev, &addr, | |
229 | i2cdev_check_mux_children); | |
230 | ||
231 | return result; | |
bd4217d8 JD |
232 | } |
233 | ||
c57d3e7a | 234 | static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client, |
7d5cb456 | 235 | unsigned nmsgs, struct i2c_msg *msgs) |
1da177e4 | 236 | { |
1da177e4 | 237 | u8 __user **data_ptrs; |
dba7997a JD |
238 | int i, res; |
239 | ||
6da2ec56 | 240 | data_ptrs = kmalloc_array(nmsgs, sizeof(u8 __user *), GFP_KERNEL); |
dba7997a | 241 | if (data_ptrs == NULL) { |
7d5cb456 | 242 | kfree(msgs); |
dba7997a JD |
243 | return -ENOMEM; |
244 | } | |
245 | ||
246 | res = 0; | |
7d5cb456 | 247 | for (i = 0; i < nmsgs; i++) { |
838bfa60 | 248 | /* Limit the size of the message to a sane amount */ |
7d5cb456 | 249 | if (msgs[i].len > 8192) { |
dba7997a JD |
250 | res = -EINVAL; |
251 | break; | |
252 | } | |
838bfa60 | 253 | |
7d5cb456 AV |
254 | data_ptrs[i] = (u8 __user *)msgs[i].buf; |
255 | msgs[i].buf = memdup_user(data_ptrs[i], msgs[i].len); | |
256 | if (IS_ERR(msgs[i].buf)) { | |
257 | res = PTR_ERR(msgs[i].buf); | |
dba7997a JD |
258 | break; |
259 | } | |
978336d4 WS |
260 | /* memdup_user allocates with GFP_KERNEL, so DMA is ok */ |
261 | msgs[i].flags |= I2C_M_DMA_SAFE; | |
838bfa60 JD |
262 | |
263 | /* | |
264 | * If the message length is received from the slave (similar | |
265 | * to SMBus block read), we must ensure that the buffer will | |
266 | * be large enough to cope with a message length of | |
267 | * I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus | |
268 | * drivers allow. The first byte in the buffer must be | |
269 | * pre-filled with the number of extra bytes, which must be | |
270 | * at least one to hold the message length, but can be | |
271 | * greater (for example to account for a checksum byte at | |
272 | * the end of the message.) | |
273 | */ | |
7d5cb456 AV |
274 | if (msgs[i].flags & I2C_M_RECV_LEN) { |
275 | if (!(msgs[i].flags & I2C_M_RD) || | |
23a27722 | 276 | msgs[i].len < 1 || msgs[i].buf[0] < 1 || |
7d5cb456 | 277 | msgs[i].len < msgs[i].buf[0] + |
838bfa60 | 278 | I2C_SMBUS_BLOCK_MAX) { |
a0692f0e | 279 | i++; |
838bfa60 JD |
280 | res = -EINVAL; |
281 | break; | |
282 | } | |
283 | ||
7d5cb456 | 284 | msgs[i].len = msgs[i].buf[0]; |
838bfa60 | 285 | } |
dba7997a JD |
286 | } |
287 | if (res < 0) { | |
288 | int j; | |
289 | for (j = 0; j < i; ++j) | |
7d5cb456 | 290 | kfree(msgs[j].buf); |
dba7997a | 291 | kfree(data_ptrs); |
7d5cb456 | 292 | kfree(msgs); |
dba7997a JD |
293 | return res; |
294 | } | |
295 | ||
7d5cb456 | 296 | res = i2c_transfer(client->adapter, msgs, nmsgs); |
dba7997a | 297 | while (i-- > 0) { |
7d5cb456 AV |
298 | if (res >= 0 && (msgs[i].flags & I2C_M_RD)) { |
299 | if (copy_to_user(data_ptrs[i], msgs[i].buf, | |
300 | msgs[i].len)) | |
dba7997a JD |
301 | res = -EFAULT; |
302 | } | |
7d5cb456 | 303 | kfree(msgs[i].buf); |
dba7997a JD |
304 | } |
305 | kfree(data_ptrs); | |
7d5cb456 | 306 | kfree(msgs); |
dba7997a JD |
307 | return res; |
308 | } | |
309 | ||
310 | static noinline int i2cdev_ioctl_smbus(struct i2c_client *client, | |
7d5cb456 AV |
311 | u8 read_write, u8 command, u32 size, |
312 | union i2c_smbus_data __user *data) | |
dba7997a | 313 | { |
30f939fe | 314 | union i2c_smbus_data temp = {}; |
dba7997a JD |
315 | int datasize, res; |
316 | ||
7d5cb456 AV |
317 | if ((size != I2C_SMBUS_BYTE) && |
318 | (size != I2C_SMBUS_QUICK) && | |
319 | (size != I2C_SMBUS_BYTE_DATA) && | |
320 | (size != I2C_SMBUS_WORD_DATA) && | |
321 | (size != I2C_SMBUS_PROC_CALL) && | |
322 | (size != I2C_SMBUS_BLOCK_DATA) && | |
323 | (size != I2C_SMBUS_I2C_BLOCK_BROKEN) && | |
324 | (size != I2C_SMBUS_I2C_BLOCK_DATA) && | |
325 | (size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
dba7997a JD |
326 | dev_dbg(&client->adapter->dev, |
327 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
7d5cb456 | 328 | size); |
dba7997a JD |
329 | return -EINVAL; |
330 | } | |
331 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, | |
332 | so the check is valid if size==I2C_SMBUS_QUICK too. */ | |
7d5cb456 AV |
333 | if ((read_write != I2C_SMBUS_READ) && |
334 | (read_write != I2C_SMBUS_WRITE)) { | |
dba7997a JD |
335 | dev_dbg(&client->adapter->dev, |
336 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", | |
7d5cb456 | 337 | read_write); |
dba7997a JD |
338 | return -EINVAL; |
339 | } | |
340 | ||
341 | /* Note that command values are always valid! */ | |
342 | ||
7d5cb456 AV |
343 | if ((size == I2C_SMBUS_QUICK) || |
344 | ((size == I2C_SMBUS_BYTE) && | |
345 | (read_write == I2C_SMBUS_WRITE))) | |
dba7997a JD |
346 | /* These are special: we do not use data */ |
347 | return i2c_smbus_xfer(client->adapter, client->addr, | |
7d5cb456 AV |
348 | client->flags, read_write, |
349 | command, size, NULL); | |
dba7997a | 350 | |
7d5cb456 | 351 | if (data == NULL) { |
dba7997a JD |
352 | dev_dbg(&client->adapter->dev, |
353 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
354 | return -EINVAL; | |
355 | } | |
356 | ||
7d5cb456 AV |
357 | if ((size == I2C_SMBUS_BYTE_DATA) || |
358 | (size == I2C_SMBUS_BYTE)) | |
359 | datasize = sizeof(data->byte); | |
360 | else if ((size == I2C_SMBUS_WORD_DATA) || | |
361 | (size == I2C_SMBUS_PROC_CALL)) | |
362 | datasize = sizeof(data->word); | |
dba7997a | 363 | else /* size == smbus block, i2c block, or block proc. call */ |
7d5cb456 | 364 | datasize = sizeof(data->block); |
dba7997a | 365 | |
7d5cb456 AV |
366 | if ((size == I2C_SMBUS_PROC_CALL) || |
367 | (size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
368 | (size == I2C_SMBUS_I2C_BLOCK_DATA) || | |
369 | (read_write == I2C_SMBUS_WRITE)) { | |
370 | if (copy_from_user(&temp, data, datasize)) | |
dba7997a JD |
371 | return -EFAULT; |
372 | } | |
7d5cb456 | 373 | if (size == I2C_SMBUS_I2C_BLOCK_BROKEN) { |
dba7997a JD |
374 | /* Convert old I2C block commands to the new |
375 | convention. This preserves binary compatibility. */ | |
7d5cb456 AV |
376 | size = I2C_SMBUS_I2C_BLOCK_DATA; |
377 | if (read_write == I2C_SMBUS_READ) | |
dba7997a JD |
378 | temp.block[0] = I2C_SMBUS_BLOCK_MAX; |
379 | } | |
380 | res = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
7d5cb456 AV |
381 | read_write, command, size, &temp); |
382 | if (!res && ((size == I2C_SMBUS_PROC_CALL) || | |
383 | (size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
384 | (read_write == I2C_SMBUS_READ))) { | |
385 | if (copy_to_user(data, &temp, datasize)) | |
dba7997a JD |
386 | return -EFAULT; |
387 | } | |
388 | return res; | |
389 | } | |
390 | ||
77e38bff | 391 | static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
dba7997a | 392 | { |
0be16c30 | 393 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
394 | unsigned long funcs; |
395 | ||
e8aafcb2 JD |
396 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
397 | cmd, arg); | |
1da177e4 | 398 | |
ae5624fc | 399 | switch (cmd) { |
1da177e4 LT |
400 | case I2C_SLAVE: |
401 | case I2C_SLAVE_FORCE: | |
438d6c2c | 402 | if ((arg > 0x3ff) || |
1da177e4 LT |
403 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) |
404 | return -EINVAL; | |
bd4217d8 | 405 | if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg)) |
1da177e4 | 406 | return -EBUSY; |
bd4217d8 | 407 | /* REVISIT: address could become busy later */ |
1da177e4 LT |
408 | client->addr = arg; |
409 | return 0; | |
410 | case I2C_TENBIT: | |
411 | if (arg) | |
412 | client->flags |= I2C_M_TEN; | |
413 | else | |
414 | client->flags &= ~I2C_M_TEN; | |
415 | return 0; | |
416 | case I2C_PEC: | |
9e685c84 JD |
417 | /* |
418 | * Setting the PEC flag here won't affect kernel drivers, | |
419 | * which will be using the i2c_client node registered with | |
420 | * the driver model core. Likewise, when that client has | |
421 | * the PEC flag already set, the i2c-dev driver won't see | |
422 | * (or use) this setting. | |
423 | */ | |
1da177e4 LT |
424 | if (arg) |
425 | client->flags |= I2C_CLIENT_PEC; | |
426 | else | |
427 | client->flags &= ~I2C_CLIENT_PEC; | |
428 | return 0; | |
429 | case I2C_FUNCS: | |
430 | funcs = i2c_get_functionality(client->adapter); | |
2c003e8e | 431 | return put_user(funcs, (unsigned long __user *)arg); |
1da177e4 | 432 | |
7d5cb456 AV |
433 | case I2C_RDWR: { |
434 | struct i2c_rdwr_ioctl_data rdwr_arg; | |
435 | struct i2c_msg *rdwr_pa; | |
436 | ||
437 | if (copy_from_user(&rdwr_arg, | |
438 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
439 | sizeof(rdwr_arg))) | |
440 | return -EFAULT; | |
441 | ||
71581562 WS |
442 | if (!rdwr_arg.msgs || rdwr_arg.nmsgs == 0) |
443 | return -EINVAL; | |
444 | ||
445 | /* | |
446 | * Put an arbitrary limit on the number of messages that can | |
447 | * be sent at once | |
448 | */ | |
7d5cb456 AV |
449 | if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) |
450 | return -EINVAL; | |
1da177e4 | 451 | |
7d5cb456 AV |
452 | rdwr_pa = memdup_user(rdwr_arg.msgs, |
453 | rdwr_arg.nmsgs * sizeof(struct i2c_msg)); | |
454 | if (IS_ERR(rdwr_pa)) | |
455 | return PTR_ERR(rdwr_pa); | |
456 | ||
457 | return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa); | |
458 | } | |
1da177e4 | 459 | |
7d5cb456 AV |
460 | case I2C_SMBUS: { |
461 | struct i2c_smbus_ioctl_data data_arg; | |
462 | if (copy_from_user(&data_arg, | |
463 | (struct i2c_smbus_ioctl_data __user *) arg, | |
464 | sizeof(struct i2c_smbus_ioctl_data))) | |
465 | return -EFAULT; | |
466 | return i2cdev_ioctl_smbus(client, data_arg.read_write, | |
467 | data_arg.command, | |
468 | data_arg.size, | |
469 | data_arg.data); | |
470 | } | |
53be7959 | 471 | case I2C_RETRIES: |
6ebec961 YZ |
472 | if (arg > INT_MAX) |
473 | return -EINVAL; | |
474 | ||
53be7959 DB |
475 | client->adapter->retries = arg; |
476 | break; | |
477 | case I2C_TIMEOUT: | |
6ebec961 YZ |
478 | if (arg > INT_MAX) |
479 | return -EINVAL; | |
480 | ||
cd97f39b JD |
481 | /* For historical reasons, user-space sets the timeout |
482 | * value in units of 10 ms. | |
483 | */ | |
484 | client->adapter->timeout = msecs_to_jiffies(arg * 10); | |
53be7959 | 485 | break; |
1da177e4 | 486 | default: |
53be7959 DB |
487 | /* NOTE: returning a fault code here could cause trouble |
488 | * in buggy userspace code. Some old kernel bugs returned | |
489 | * zero in this case, and userspace code might accidentally | |
490 | * have depended on that bug. | |
491 | */ | |
492 | return -ENOTTY; | |
1da177e4 LT |
493 | } |
494 | return 0; | |
495 | } | |
496 | ||
7d5cb456 AV |
497 | #ifdef CONFIG_COMPAT |
498 | ||
499 | struct i2c_smbus_ioctl_data32 { | |
500 | u8 read_write; | |
501 | u8 command; | |
502 | u32 size; | |
503 | compat_caddr_t data; /* union i2c_smbus_data *data */ | |
504 | }; | |
505 | ||
506 | struct i2c_msg32 { | |
507 | u16 addr; | |
508 | u16 flags; | |
509 | u16 len; | |
510 | compat_caddr_t buf; | |
511 | }; | |
512 | ||
513 | struct i2c_rdwr_ioctl_data32 { | |
514 | compat_caddr_t msgs; /* struct i2c_msg __user *msgs */ | |
515 | u32 nmsgs; | |
516 | }; | |
517 | ||
518 | static long compat_i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
519 | { | |
520 | struct i2c_client *client = file->private_data; | |
521 | unsigned long funcs; | |
522 | switch (cmd) { | |
523 | case I2C_FUNCS: | |
524 | funcs = i2c_get_functionality(client->adapter); | |
525 | return put_user(funcs, (compat_ulong_t __user *)arg); | |
526 | case I2C_RDWR: { | |
527 | struct i2c_rdwr_ioctl_data32 rdwr_arg; | |
3265a7e6 | 528 | struct i2c_msg32 __user *p; |
7d5cb456 AV |
529 | struct i2c_msg *rdwr_pa; |
530 | int i; | |
531 | ||
532 | if (copy_from_user(&rdwr_arg, | |
533 | (struct i2c_rdwr_ioctl_data32 __user *)arg, | |
534 | sizeof(rdwr_arg))) | |
535 | return -EFAULT; | |
536 | ||
537 | if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) | |
538 | return -EINVAL; | |
539 | ||
540 | rdwr_pa = kmalloc_array(rdwr_arg.nmsgs, sizeof(struct i2c_msg), | |
541 | GFP_KERNEL); | |
542 | if (!rdwr_pa) | |
543 | return -ENOMEM; | |
544 | ||
545 | p = compat_ptr(rdwr_arg.msgs); | |
546 | for (i = 0; i < rdwr_arg.nmsgs; i++) { | |
547 | struct i2c_msg32 umsg; | |
548 | if (copy_from_user(&umsg, p + i, sizeof(umsg))) { | |
549 | kfree(rdwr_pa); | |
550 | return -EFAULT; | |
551 | } | |
552 | rdwr_pa[i] = (struct i2c_msg) { | |
553 | .addr = umsg.addr, | |
554 | .flags = umsg.flags, | |
555 | .len = umsg.len, | |
556 | .buf = compat_ptr(umsg.buf) | |
557 | }; | |
558 | } | |
559 | ||
560 | return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa); | |
561 | } | |
562 | case I2C_SMBUS: { | |
563 | struct i2c_smbus_ioctl_data32 data32; | |
564 | if (copy_from_user(&data32, | |
565 | (void __user *) arg, | |
566 | sizeof(data32))) | |
567 | return -EFAULT; | |
568 | return i2cdev_ioctl_smbus(client, data32.read_write, | |
569 | data32.command, | |
570 | data32.size, | |
571 | compat_ptr(data32.data)); | |
572 | } | |
573 | default: | |
574 | return i2cdev_ioctl(file, cmd, arg); | |
575 | } | |
576 | } | |
577 | #else | |
578 | #define compat_i2cdev_ioctl NULL | |
579 | #endif | |
580 | ||
1da177e4 LT |
581 | static int i2cdev_open(struct inode *inode, struct file *file) |
582 | { | |
583 | unsigned int minor = iminor(inode); | |
584 | struct i2c_client *client; | |
585 | struct i2c_adapter *adap; | |
1da177e4 | 586 | |
5136ed4f | 587 | adap = i2c_get_adapter(minor); |
9669f541 VS |
588 | if (!adap) |
589 | return -ENODEV; | |
1da177e4 | 590 | |
907135aa DB |
591 | /* This creates an anonymous i2c_client, which may later be |
592 | * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE. | |
593 | * | |
594 | * This client is ** NEVER REGISTERED ** with the driver model | |
595 | * or I2C core code!! It just holds private copies of addressing | |
596 | * information and maybe a PEC flag. | |
597 | */ | |
22f76e74 | 598 | client = kzalloc(sizeof(*client), GFP_KERNEL); |
1da177e4 LT |
599 | if (!client) { |
600 | i2c_put_adapter(adap); | |
9669f541 | 601 | return -ENOMEM; |
1da177e4 | 602 | } |
22f76e74 | 603 | snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); |
1da177e4 | 604 | |
1da177e4 LT |
605 | client->adapter = adap; |
606 | file->private_data = client; | |
607 | ||
9669f541 | 608 | return 0; |
1da177e4 LT |
609 | } |
610 | ||
611 | static int i2cdev_release(struct inode *inode, struct file *file) | |
612 | { | |
613 | struct i2c_client *client = file->private_data; | |
614 | ||
615 | i2c_put_adapter(client->adapter); | |
616 | kfree(client); | |
617 | file->private_data = NULL; | |
618 | ||
619 | return 0; | |
620 | } | |
621 | ||
2b8693c0 | 622 | static const struct file_operations i2cdev_fops = { |
1da177e4 LT |
623 | .owner = THIS_MODULE, |
624 | .llseek = no_llseek, | |
625 | .read = i2cdev_read, | |
626 | .write = i2cdev_write, | |
77e38bff | 627 | .unlocked_ioctl = i2cdev_ioctl, |
7d5cb456 | 628 | .compat_ioctl = compat_i2cdev_ioctl, |
1da177e4 LT |
629 | .open = i2cdev_open, |
630 | .release = i2cdev_release, | |
631 | }; | |
632 | ||
907135aa DB |
633 | /* ------------------------------------------------------------------------- */ |
634 | ||
79472132 | 635 | static struct class *i2c_dev_class; |
1da177e4 | 636 | |
1413ef63 KH |
637 | static void i2cdev_dev_release(struct device *dev) |
638 | { | |
639 | struct i2c_dev *i2c_dev; | |
640 | ||
641 | i2c_dev = container_of(dev, struct i2c_dev, dev); | |
642 | kfree(i2c_dev); | |
643 | } | |
644 | ||
9ea3e941 | 645 | static int i2cdev_attach_adapter(struct device *dev, void *dummy) |
1da177e4 | 646 | { |
9ea3e941 | 647 | struct i2c_adapter *adap; |
1da177e4 | 648 | struct i2c_dev *i2c_dev; |
defcb46e | 649 | int res; |
1da177e4 | 650 | |
9ea3e941 JD |
651 | if (dev->type != &i2c_adapter_type) |
652 | return 0; | |
653 | adap = to_i2c_adapter(dev); | |
654 | ||
1da177e4 LT |
655 | i2c_dev = get_free_i2c_dev(adap); |
656 | if (IS_ERR(i2c_dev)) | |
657 | return PTR_ERR(i2c_dev); | |
658 | ||
d6760b14 EN |
659 | cdev_init(&i2c_dev->cdev, &i2cdev_fops); |
660 | i2c_dev->cdev.owner = THIS_MODULE; | |
1413ef63 KH |
661 | |
662 | device_initialize(&i2c_dev->dev); | |
663 | i2c_dev->dev.devt = MKDEV(I2C_MAJOR, adap->nr); | |
664 | i2c_dev->dev.class = i2c_dev_class; | |
665 | i2c_dev->dev.parent = &adap->dev; | |
666 | i2c_dev->dev.release = i2cdev_dev_release; | |
667 | dev_set_name(&i2c_dev->dev, "i2c-%d", adap->nr); | |
668 | ||
669 | res = cdev_device_add(&i2c_dev->cdev, &i2c_dev->dev); | |
670 | if (res) { | |
671 | put_i2c_dev(i2c_dev, false); | |
672 | return res; | |
defcb46e | 673 | } |
b32d20dc | 674 | |
295e0e7b | 675 | pr_debug("adapter [%s] registered as minor %d\n", adap->name, adap->nr); |
1da177e4 | 676 | return 0; |
1da177e4 LT |
677 | } |
678 | ||
9ea3e941 | 679 | static int i2cdev_detach_adapter(struct device *dev, void *dummy) |
1da177e4 | 680 | { |
9ea3e941 | 681 | struct i2c_adapter *adap; |
1da177e4 LT |
682 | struct i2c_dev *i2c_dev; |
683 | ||
9ea3e941 JD |
684 | if (dev->type != &i2c_adapter_type) |
685 | return 0; | |
686 | adap = to_i2c_adapter(dev); | |
687 | ||
9455e4c9 | 688 | i2c_dev = i2c_dev_get_by_minor(adap->nr); |
b32d20dc JD |
689 | if (!i2c_dev) /* attach_adapter must have failed */ |
690 | return 0; | |
1da177e4 | 691 | |
1413ef63 | 692 | put_i2c_dev(i2c_dev, true); |
1da177e4 | 693 | |
295e0e7b | 694 | pr_debug("adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
695 | return 0; |
696 | } | |
697 | ||
eff245c8 | 698 | static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action, |
9ea3e941 JD |
699 | void *data) |
700 | { | |
701 | struct device *dev = data; | |
702 | ||
703 | switch (action) { | |
704 | case BUS_NOTIFY_ADD_DEVICE: | |
705 | return i2cdev_attach_adapter(dev, NULL); | |
706 | case BUS_NOTIFY_DEL_DEVICE: | |
707 | return i2cdev_detach_adapter(dev, NULL); | |
708 | } | |
709 | ||
710 | return 0; | |
711 | } | |
712 | ||
713 | static struct notifier_block i2cdev_notifier = { | |
714 | .notifier_call = i2cdev_notifier_call, | |
1da177e4 LT |
715 | }; |
716 | ||
907135aa DB |
717 | /* ------------------------------------------------------------------------- */ |
718 | ||
719 | /* | |
720 | * module load/unload record keeping | |
721 | */ | |
722 | ||
1da177e4 LT |
723 | static int __init i2c_dev_init(void) |
724 | { | |
725 | int res; | |
726 | ||
295e0e7b | 727 | pr_info("i2c /dev entries driver\n"); |
1da177e4 | 728 | |
d6760b14 | 729 | res = register_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS, "i2c"); |
1da177e4 LT |
730 | if (res) |
731 | goto out; | |
732 | ||
79472132 | 733 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
e74783ec SW |
734 | if (IS_ERR(i2c_dev_class)) { |
735 | res = PTR_ERR(i2c_dev_class); | |
1da177e4 | 736 | goto out_unreg_chrdev; |
e74783ec | 737 | } |
45f176ae | 738 | i2c_dev_class->dev_groups = i2c_groups; |
1da177e4 | 739 | |
9ea3e941 JD |
740 | /* Keep track of adapters which will be added or removed later */ |
741 | res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier); | |
1da177e4 LT |
742 | if (res) |
743 | goto out_unreg_class; | |
744 | ||
9ea3e941 JD |
745 | /* Bind to already existing adapters right away */ |
746 | i2c_for_each_dev(NULL, i2cdev_attach_adapter); | |
747 | ||
1da177e4 LT |
748 | return 0; |
749 | ||
750 | out_unreg_class: | |
79472132 | 751 | class_destroy(i2c_dev_class); |
1da177e4 | 752 | out_unreg_chrdev: |
d6760b14 | 753 | unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS); |
1da177e4 | 754 | out: |
295e0e7b | 755 | pr_err("Driver Initialisation failed\n"); |
1da177e4 LT |
756 | return res; |
757 | } | |
758 | ||
759 | static void __exit i2c_dev_exit(void) | |
760 | { | |
9ea3e941 JD |
761 | bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier); |
762 | i2c_for_each_dev(NULL, i2cdev_detach_adapter); | |
79472132 | 763 | class_destroy(i2c_dev_class); |
d6760b14 | 764 | unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS); |
1da177e4 LT |
765 | } |
766 | ||
f80531c8 JN |
767 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>"); |
768 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
1da177e4 LT |
769 | MODULE_DESCRIPTION("I2C /dev entries driver"); |
770 | MODULE_LICENSE("GPL"); | |
771 | ||
772 | module_init(i2c_dev_init); | |
773 | module_exit(i2c_dev_exit); |