blob: 45048323b75eab01d5875cb05464207c2eb614b3 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
David Brownell438d6c22006-12-10 21:21:31 +01002 i2c-dev.c - i2c-bus driver, char device interface
Linus Torvalds1da177e2005-04-16 15:20:36 -07003
4 Copyright (C) 1995-97 Simon G. Vogl
5 Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
6 Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
Jean Delvare5694f8a2012-03-26 21:47:19 +020020 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
21 MA 02110-1301 USA.
Linus Torvalds1da177e2005-04-16 15:20:36 -070022*/
23
24/* Note that this is a complete rewrite of Simon Vogl's i2c-dev module.
25 But I have used so much of his original code and ideas that it seems
26 only fair to recognize him as co-author -- Frodo */
27
28/* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */
29
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/kernel.h>
31#include <linux/module.h>
Jean Delvare9ea3e942011-03-20 14:50:52 +010032#include <linux/device.h>
33#include <linux/notifier.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/fs.h>
35#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include <linux/init.h>
Jean Delvaref3b3aad2006-07-01 17:17:38 +020037#include <linux/list.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <linux/i2c.h>
39#include <linux/i2c-dev.h>
Jean Delvarecd97f392009-02-24 19:19:49 +010040#include <linux/jiffies.h>
Farid Hammaneae5624f2010-05-21 18:40:59 +020041#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
David Brownell907135a2007-11-15 19:24:01 +010043/*
44 * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a
45 * slave (i2c_client) with which messages will be exchanged. It's coupled
46 * with a character special file which is accessed by user mode drivers.
47 *
48 * The list of i2c_dev structures is parallel to the i2c_adapter lists
Jean Delvare9ea3e942011-03-20 14:50:52 +010049 * maintained by the driver model, and is updated using bus notifications.
David Brownell907135a2007-11-15 19:24:01 +010050 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070051struct i2c_dev {
Jean Delvaref3b3aad2006-07-01 17:17:38 +020052 struct list_head list;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 struct i2c_adapter *adap;
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -070054 struct device *dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055};
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
57#define I2C_MINORS 256
Jean Delvaref3b3aad2006-07-01 17:17:38 +020058static LIST_HEAD(i2c_dev_list);
59static DEFINE_SPINLOCK(i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070060
61static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
62{
63 struct i2c_dev *i2c_dev;
64
Jean Delvaref3b3aad2006-07-01 17:17:38 +020065 spin_lock(&i2c_dev_list_lock);
66 list_for_each_entry(i2c_dev, &i2c_dev_list, list) {
67 if (i2c_dev->adap->nr == index)
68 goto found;
69 }
70 i2c_dev = NULL;
71found:
72 spin_unlock(&i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 return i2c_dev;
74}
75
Linus Torvalds1da177e2005-04-16 15:20:36 -070076static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
77{
78 struct i2c_dev *i2c_dev;
79
Jean Delvaref3b3aad2006-07-01 17:17:38 +020080 if (adap->nr >= I2C_MINORS) {
81 printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
82 adap->nr);
83 return ERR_PTR(-ENODEV);
84 }
85
Deepak Saxena5263ebb2005-10-17 23:09:43 +020086 i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 if (!i2c_dev)
88 return ERR_PTR(-ENOMEM);
Jean Delvare9455e4c2006-07-01 17:16:57 +020089 i2c_dev->adap = adap;
Jean Delvaref3b3aad2006-07-01 17:17:38 +020090
91 spin_lock(&i2c_dev_list_lock);
92 list_add_tail(&i2c_dev->list, &i2c_dev_list);
93 spin_unlock(&i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 return i2c_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070095}
96
97static void return_i2c_dev(struct i2c_dev *i2c_dev)
98{
Jean Delvaref3b3aad2006-07-01 17:17:38 +020099 spin_lock(&i2c_dev_list_lock);
100 list_del(&i2c_dev->list);
101 spin_unlock(&i2c_dev_list_lock);
Jean Delvare07125ab2006-12-10 21:21:33 +0100102 kfree(i2c_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103}
104
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700105static ssize_t show_adapter_name(struct device *dev,
106 struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107{
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700108 struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt));
Greg Kroah-Hartman79472132005-12-06 15:33:15 -0800109
110 if (!i2c_dev)
111 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 return sprintf(buf, "%s\n", i2c_dev->adap->name);
113}
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700114static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115
David Brownell907135a2007-11-15 19:24:01 +0100116/* ------------------------------------------------------------------------- */
117
118/*
119 * After opening an instance of this character special file, a file
120 * descriptor starts out associated only with an i2c_adapter (and bus).
121 *
122 * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg
123 * traffic to any devices on the bus used by that adapter. That's because
124 * the i2c_msg vectors embed all the addressing information they need, and
125 * are submitted directly to an i2c_adapter. However, SMBus-only adapters
126 * don't support that interface.
127 *
128 * To use read()/write() system calls on that file descriptor, or to use
129 * SMBus interfaces (and work with SMBus-only hosts!), you must first issue
130 * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous
131 * (never registered) i2c_client so it holds the addressing information
132 * needed by those system calls and by this SMBus interface.
133 */
134
Farid Hammaneae5624f2010-05-21 18:40:59 +0200135static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count,
136 loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137{
138 char *tmp;
139 int ret;
140
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200141 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
143 if (count > 8192)
144 count = 8192;
145
Farid Hammaneae5624f2010-05-21 18:40:59 +0200146 tmp = kmalloc(count, GFP_KERNEL);
147 if (tmp == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 return -ENOMEM;
149
David Brownell2ce5b342008-08-10 22:56:16 +0200150 pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n",
Josef Sipekcba0a122006-12-08 02:37:08 -0800151 iminor(file->f_path.dentry->d_inode), count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
Farid Hammaneae5624f2010-05-21 18:40:59 +0200153 ret = i2c_master_recv(client, tmp, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 if (ret >= 0)
Farid Hammaneae5624f2010-05-21 18:40:59 +0200155 ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 kfree(tmp);
157 return ret;
158}
159
Farid Hammaneae5624f2010-05-21 18:40:59 +0200160static ssize_t i2cdev_write(struct file *file, const char __user *buf,
161 size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162{
163 int ret;
164 char *tmp;
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200165 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166
167 if (count > 8192)
168 count = 8192;
169
Julia Lawallf1c2e332010-08-11 18:20:55 +0200170 tmp = memdup_user(buf, count);
171 if (IS_ERR(tmp))
172 return PTR_ERR(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173
David Brownell2ce5b342008-08-10 22:56:16 +0200174 pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n",
Josef Sipekcba0a122006-12-08 02:37:08 -0800175 iminor(file->f_path.dentry->d_inode), count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
Farid Hammaneae5624f2010-05-21 18:40:59 +0200177 ret = i2c_master_send(client, tmp, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 kfree(tmp);
179 return ret;
180}
181
David Brownell9b766b82008-01-27 18:14:51 +0100182static int i2cdev_check(struct device *dev, void *addrp)
183{
184 struct i2c_client *client = i2c_verify_client(dev);
185
186 if (!client || client->addr != *(unsigned int *)addrp)
187 return 0;
188
189 return dev->driver ? -EBUSY : 0;
190}
191
Michael Lawnick08263742010-08-11 18:21:02 +0200192/* walk up mux tree */
193static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
194{
Jean Delvare97cc4d42010-10-24 18:16:57 +0200195 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
Michael Lawnick08263742010-08-11 18:21:02 +0200196 int result;
197
198 result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
Jean Delvare97cc4d42010-10-24 18:16:57 +0200199 if (!result && parent)
200 result = i2cdev_check_mux_parents(parent, addr);
Michael Lawnick08263742010-08-11 18:21:02 +0200201
202 return result;
203}
204
205/* recurse down mux tree */
206static int i2cdev_check_mux_children(struct device *dev, void *addrp)
207{
208 int result;
209
210 if (dev->type == &i2c_adapter_type)
211 result = device_for_each_child(dev, addrp,
212 i2cdev_check_mux_children);
213 else
214 result = i2cdev_check(dev, addrp);
215
216 return result;
217}
218
Jean Delvarebd4217d2007-11-15 19:24:01 +0100219/* This address checking function differs from the one in i2c-core
220 in that it considers an address with a registered device, but no
David Brownell9b766b82008-01-27 18:14:51 +0100221 driver bound to it, as NOT busy. */
Jean Delvarebd4217d2007-11-15 19:24:01 +0100222static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
223{
Jean Delvare97cc4d42010-10-24 18:16:57 +0200224 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
Michael Lawnick08263742010-08-11 18:21:02 +0200225 int result = 0;
226
Jean Delvare97cc4d42010-10-24 18:16:57 +0200227 if (parent)
228 result = i2cdev_check_mux_parents(parent, addr);
Michael Lawnick08263742010-08-11 18:21:02 +0200229
230 if (!result)
231 result = device_for_each_child(&adapter->dev, &addr,
232 i2cdev_check_mux_children);
233
234 return result;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100235}
236
Jean Delvaredba79972008-04-22 22:16:47 +0200237static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
238 unsigned long arg)
239{
240 struct i2c_rdwr_ioctl_data rdwr_arg;
241 struct i2c_msg *rdwr_pa;
242 u8 __user **data_ptrs;
243 int i, res;
244
245 if (copy_from_user(&rdwr_arg,
246 (struct i2c_rdwr_ioctl_data __user *)arg,
247 sizeof(rdwr_arg)))
248 return -EFAULT;
249
250 /* Put an arbitrary limit on the number of messages that can
251 * be sent at once */
252 if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
253 return -EINVAL;
254
Thomas Meyera699ed6f2012-01-12 20:32:04 +0100255 rdwr_pa = memdup_user(rdwr_arg.msgs,
256 rdwr_arg.nmsgs * sizeof(struct i2c_msg));
257 if (IS_ERR(rdwr_pa))
258 return PTR_ERR(rdwr_pa);
Jean Delvaredba79972008-04-22 22:16:47 +0200259
260 data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
261 if (data_ptrs == NULL) {
262 kfree(rdwr_pa);
263 return -ENOMEM;
264 }
265
266 res = 0;
267 for (i = 0; i < rdwr_arg.nmsgs; i++) {
268 /* Limit the size of the message to a sane amount;
269 * and don't let length change either. */
270 if ((rdwr_pa[i].len > 8192) ||
271 (rdwr_pa[i].flags & I2C_M_RECV_LEN)) {
272 res = -EINVAL;
273 break;
274 }
275 data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
Julia Lawallf1c2e332010-08-11 18:20:55 +0200276 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);
Jean Delvaredba79972008-04-22 22:16:47 +0200279 break;
280 }
281 }
282 if (res < 0) {
283 int j;
284 for (j = 0; j < i; ++j)
285 kfree(rdwr_pa[j].buf);
286 kfree(data_ptrs);
287 kfree(rdwr_pa);
288 return res;
289 }
290
291 res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs);
292 while (i-- > 0) {
293 if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) {
294 if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf,
295 rdwr_pa[i].len))
296 res = -EFAULT;
297 }
298 kfree(rdwr_pa[i].buf);
299 }
300 kfree(data_ptrs);
301 kfree(rdwr_pa);
302 return res;
303}
304
305static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
306 unsigned long arg)
307{
308 struct i2c_smbus_ioctl_data data_arg;
309 union i2c_smbus_data temp;
310 int datasize, res;
311
312 if (copy_from_user(&data_arg,
313 (struct i2c_smbus_ioctl_data __user *) arg,
314 sizeof(struct i2c_smbus_ioctl_data)))
315 return -EFAULT;
316 if ((data_arg.size != I2C_SMBUS_BYTE) &&
317 (data_arg.size != I2C_SMBUS_QUICK) &&
318 (data_arg.size != I2C_SMBUS_BYTE_DATA) &&
319 (data_arg.size != I2C_SMBUS_WORD_DATA) &&
320 (data_arg.size != I2C_SMBUS_PROC_CALL) &&
321 (data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
322 (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
323 (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
324 (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
325 dev_dbg(&client->adapter->dev,
326 "size out of range (%x) in ioctl I2C_SMBUS.\n",
327 data_arg.size);
328 return -EINVAL;
329 }
330 /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
331 so the check is valid if size==I2C_SMBUS_QUICK too. */
332 if ((data_arg.read_write != I2C_SMBUS_READ) &&
333 (data_arg.read_write != I2C_SMBUS_WRITE)) {
334 dev_dbg(&client->adapter->dev,
335 "read_write out of range (%x) in ioctl I2C_SMBUS.\n",
336 data_arg.read_write);
337 return -EINVAL;
338 }
339
340 /* Note that command values are always valid! */
341
342 if ((data_arg.size == I2C_SMBUS_QUICK) ||
343 ((data_arg.size == I2C_SMBUS_BYTE) &&
344 (data_arg.read_write == I2C_SMBUS_WRITE)))
345 /* These are special: we do not use data */
346 return i2c_smbus_xfer(client->adapter, client->addr,
347 client->flags, data_arg.read_write,
348 data_arg.command, data_arg.size, NULL);
349
350 if (data_arg.data == NULL) {
351 dev_dbg(&client->adapter->dev,
352 "data is NULL pointer in ioctl I2C_SMBUS.\n");
353 return -EINVAL;
354 }
355
356 if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
357 (data_arg.size == I2C_SMBUS_BYTE))
358 datasize = sizeof(data_arg.data->byte);
359 else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
360 (data_arg.size == I2C_SMBUS_PROC_CALL))
361 datasize = sizeof(data_arg.data->word);
362 else /* size == smbus block, i2c block, or block proc. call */
363 datasize = sizeof(data_arg.data->block);
364
365 if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
366 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
367 (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
368 (data_arg.read_write == I2C_SMBUS_WRITE)) {
369 if (copy_from_user(&temp, data_arg.data, datasize))
370 return -EFAULT;
371 }
372 if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
373 /* Convert old I2C block commands to the new
374 convention. This preserves binary compatibility. */
375 data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
376 if (data_arg.read_write == I2C_SMBUS_READ)
377 temp.block[0] = I2C_SMBUS_BLOCK_MAX;
378 }
379 res = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
380 data_arg.read_write, data_arg.command, data_arg.size, &temp);
381 if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
382 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
383 (data_arg.read_write == I2C_SMBUS_READ))) {
384 if (copy_to_user(data_arg.data, &temp, datasize))
385 return -EFAULT;
386 }
387 return res;
388}
389
Alan Cox77e38bf2008-07-14 22:38:27 +0200390static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391{
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200392 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 unsigned long funcs;
394
Jean Delvaree8aafcb2005-10-07 23:06:27 +0200395 dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
396 cmd, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397
Farid Hammaneae5624f2010-05-21 18:40:59 +0200398 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 case I2C_SLAVE:
400 case I2C_SLAVE_FORCE:
David Brownell907135a2007-11-15 19:24:01 +0100401 /* NOTE: devices set up to work with "new style" drivers
402 * can't use I2C_SLAVE, even when the device node is not
403 * bound to a driver. Only I2C_SLAVE_FORCE will work.
404 *
405 * Setting the PEC flag here won't affect kernel drivers,
406 * which will be using the i2c_client node registered with
407 * the driver model core. Likewise, when that client has
408 * the PEC flag already set, the i2c-dev driver won't see
409 * (or use) this setting.
410 */
David Brownell438d6c22006-12-10 21:21:31 +0100411 if ((arg > 0x3ff) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
413 return -EINVAL;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100414 if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 return -EBUSY;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100416 /* REVISIT: address could become busy later */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 client->addr = arg;
418 return 0;
419 case I2C_TENBIT:
420 if (arg)
421 client->flags |= I2C_M_TEN;
422 else
423 client->flags &= ~I2C_M_TEN;
424 return 0;
425 case I2C_PEC:
426 if (arg)
427 client->flags |= I2C_CLIENT_PEC;
428 else
429 client->flags &= ~I2C_CLIENT_PEC;
430 return 0;
431 case I2C_FUNCS:
432 funcs = i2c_get_functionality(client->adapter);
Jean Delvare2c003e82006-12-10 21:21:30 +0100433 return put_user(funcs, (unsigned long __user *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434
435 case I2C_RDWR:
Jean Delvaredba79972008-04-22 22:16:47 +0200436 return i2cdev_ioctl_rdrw(client, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437
438 case I2C_SMBUS:
Jean Delvaredba79972008-04-22 22:16:47 +0200439 return i2cdev_ioctl_smbus(client, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440
David Brownell53be7952007-10-13 23:56:32 +0200441 case I2C_RETRIES:
442 client->adapter->retries = arg;
443 break;
444 case I2C_TIMEOUT:
Jean Delvarecd97f392009-02-24 19:19:49 +0100445 /* For historical reasons, user-space sets the timeout
446 * value in units of 10 ms.
447 */
448 client->adapter->timeout = msecs_to_jiffies(arg * 10);
David Brownell53be7952007-10-13 23:56:32 +0200449 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 default:
David Brownell53be7952007-10-13 23:56:32 +0200451 /* NOTE: returning a fault code here could cause trouble
452 * in buggy userspace code. Some old kernel bugs returned
453 * zero in this case, and userspace code might accidentally
454 * have depended on that bug.
455 */
456 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 }
458 return 0;
459}
460
461static int i2cdev_open(struct inode *inode, struct file *file)
462{
463 unsigned int minor = iminor(inode);
464 struct i2c_client *client;
465 struct i2c_adapter *adap;
466 struct i2c_dev *i2c_dev;
467
468 i2c_dev = i2c_dev_get_by_minor(minor);
Vincent Sanders9669f542009-12-06 17:06:26 +0100469 if (!i2c_dev)
470 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471
472 adap = i2c_get_adapter(i2c_dev->adap->nr);
Vincent Sanders9669f542009-12-06 17:06:26 +0100473 if (!adap)
474 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475
David Brownell907135a2007-11-15 19:24:01 +0100476 /* This creates an anonymous i2c_client, which may later be
477 * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE.
478 *
479 * This client is ** NEVER REGISTERED ** with the driver model
480 * or I2C core code!! It just holds private copies of addressing
481 * information and maybe a PEC flag.
482 */
Jean Delvare22f76e72006-07-01 17:20:57 +0200483 client = kzalloc(sizeof(*client), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 if (!client) {
485 i2c_put_adapter(adap);
Vincent Sanders9669f542009-12-06 17:06:26 +0100486 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 }
Jean Delvare22f76e72006-07-01 17:20:57 +0200488 snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 client->adapter = adap;
491 file->private_data = client;
492
Vincent Sanders9669f542009-12-06 17:06:26 +0100493 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494}
495
496static int i2cdev_release(struct inode *inode, struct file *file)
497{
498 struct i2c_client *client = file->private_data;
499
500 i2c_put_adapter(client->adapter);
501 kfree(client);
502 file->private_data = NULL;
503
504 return 0;
505}
506
Arjan van de Ven2b8693c2007-02-12 00:55:32 -0800507static const struct file_operations i2cdev_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 .owner = THIS_MODULE,
509 .llseek = no_llseek,
510 .read = i2cdev_read,
511 .write = i2cdev_write,
Alan Cox77e38bf2008-07-14 22:38:27 +0200512 .unlocked_ioctl = i2cdev_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 .open = i2cdev_open,
514 .release = i2cdev_release,
515};
516
David Brownell907135a2007-11-15 19:24:01 +0100517/* ------------------------------------------------------------------------- */
518
Greg Kroah-Hartman79472132005-12-06 15:33:15 -0800519static struct class *i2c_dev_class;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520
Jean Delvare9ea3e942011-03-20 14:50:52 +0100521static int i2cdev_attach_adapter(struct device *dev, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100523 struct i2c_adapter *adap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 struct i2c_dev *i2c_dev;
Jean Delvaredefcb462006-08-15 18:30:24 +0200525 int res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526
Jean Delvare9ea3e942011-03-20 14:50:52 +0100527 if (dev->type != &i2c_adapter_type)
528 return 0;
529 adap = to_i2c_adapter(dev);
530
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 i2c_dev = get_free_i2c_dev(adap);
532 if (IS_ERR(i2c_dev))
533 return PTR_ERR(i2c_dev);
534
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 /* register this i2c device with the driver core */
Greg Kroah-Hartmana9b12612008-07-21 20:03:34 -0700536 i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
537 MKDEV(I2C_MAJOR, adap->nr), NULL,
538 "i2c-%d", adap->nr);
Akinobu Mita3bacb362006-12-10 21:21:33 +0100539 if (IS_ERR(i2c_dev->dev)) {
540 res = PTR_ERR(i2c_dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 goto error;
Jean Delvaredefcb462006-08-15 18:30:24 +0200542 }
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700543 res = device_create_file(i2c_dev->dev, &dev_attr_name);
Jean Delvaredefcb462006-08-15 18:30:24 +0200544 if (res)
545 goto error_destroy;
Jean Delvareb32d20d2006-09-03 22:19:25 +0200546
547 pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
548 adap->name, adap->nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 return 0;
Jean Delvaredefcb462006-08-15 18:30:24 +0200550error_destroy:
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700551 device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552error:
553 return_i2c_dev(i2c_dev);
Jean Delvaredefcb462006-08-15 18:30:24 +0200554 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555}
556
Jean Delvare9ea3e942011-03-20 14:50:52 +0100557static int i2cdev_detach_adapter(struct device *dev, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100559 struct i2c_adapter *adap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 struct i2c_dev *i2c_dev;
561
Jean Delvare9ea3e942011-03-20 14:50:52 +0100562 if (dev->type != &i2c_adapter_type)
563 return 0;
564 adap = to_i2c_adapter(dev);
565
Jean Delvare9455e4c2006-07-01 17:16:57 +0200566 i2c_dev = i2c_dev_get_by_minor(adap->nr);
Jean Delvareb32d20d2006-09-03 22:19:25 +0200567 if (!i2c_dev) /* attach_adapter must have failed */
568 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700570 device_remove_file(i2c_dev->dev, &dev_attr_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 return_i2c_dev(i2c_dev);
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700572 device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573
Jean Delvareb6d7b3d2005-07-31 19:02:53 +0200574 pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 return 0;
576}
577
Shubhrajyoti Deff245c2011-11-23 11:33:07 +0100578static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action,
Jean Delvare9ea3e942011-03-20 14:50:52 +0100579 void *data)
580{
581 struct device *dev = data;
582
583 switch (action) {
584 case BUS_NOTIFY_ADD_DEVICE:
585 return i2cdev_attach_adapter(dev, NULL);
586 case BUS_NOTIFY_DEL_DEVICE:
587 return i2cdev_detach_adapter(dev, NULL);
588 }
589
590 return 0;
591}
592
593static struct notifier_block i2cdev_notifier = {
594 .notifier_call = i2cdev_notifier_call,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595};
596
David Brownell907135a2007-11-15 19:24:01 +0100597/* ------------------------------------------------------------------------- */
598
599/*
600 * module load/unload record keeping
601 */
602
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603static int __init i2c_dev_init(void)
604{
605 int res;
606
607 printk(KERN_INFO "i2c /dev entries driver\n");
608
609 res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops);
610 if (res)
611 goto out;
612
Greg Kroah-Hartman79472132005-12-06 15:33:15 -0800613 i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
Sven Wegenere74783e2008-09-24 13:39:21 +0200614 if (IS_ERR(i2c_dev_class)) {
615 res = PTR_ERR(i2c_dev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 goto out_unreg_chrdev;
Sven Wegenere74783e2008-09-24 13:39:21 +0200617 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618
Jean Delvare9ea3e942011-03-20 14:50:52 +0100619 /* Keep track of adapters which will be added or removed later */
620 res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 if (res)
622 goto out_unreg_class;
623
Jean Delvare9ea3e942011-03-20 14:50:52 +0100624 /* Bind to already existing adapters right away */
625 i2c_for_each_dev(NULL, i2cdev_attach_adapter);
626
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 return 0;
628
629out_unreg_class:
Greg Kroah-Hartman79472132005-12-06 15:33:15 -0800630 class_destroy(i2c_dev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631out_unreg_chrdev:
632 unregister_chrdev(I2C_MAJOR, "i2c");
633out:
634 printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
635 return res;
636}
637
638static void __exit i2c_dev_exit(void)
639{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100640 bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier);
641 i2c_for_each_dev(NULL, i2cdev_detach_adapter);
Greg Kroah-Hartman79472132005-12-06 15:33:15 -0800642 class_destroy(i2c_dev_class);
Farid Hammaneae5624f2010-05-21 18:40:59 +0200643 unregister_chrdev(I2C_MAJOR, "i2c");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644}
645
646MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
647 "Simon G. Vogl <simon@tk.uni-linz.ac.at>");
648MODULE_DESCRIPTION("I2C /dev entries driver");
649MODULE_LICENSE("GPL");
650
651module_init(i2c_dev_init);
652module_exit(i2c_dev_exit);