blob: c90ce50b619f7b483b85483a24457a8cab73f3c2 [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
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21*/
22
23/* Note that this is a complete rewrite of Simon Vogl's i2c-dev module.
24 But I have used so much of his original code and ideas that it seems
25 only fair to recognize him as co-author -- Frodo */
26
27/* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */
28
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <linux/kernel.h>
30#include <linux/module.h>
Jean Delvare9ea3e942011-03-20 14:50:52 +010031#include <linux/device.h>
32#include <linux/notifier.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/fs.h>
34#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <linux/init.h>
Jean Delvaref3b3aad2006-07-01 17:17:38 +020036#include <linux/list.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <linux/i2c.h>
38#include <linux/i2c-dev.h>
Jean Delvarecd97f392009-02-24 19:19:49 +010039#include <linux/jiffies.h>
Farid Hammaneae5624f2010-05-21 18:40:59 +020040#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
David Brownell907135a2007-11-15 19:24:01 +010042/*
43 * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a
44 * slave (i2c_client) with which messages will be exchanged. It's coupled
45 * with a character special file which is accessed by user mode drivers.
46 *
47 * The list of i2c_dev structures is parallel to the i2c_adapter lists
Jean Delvare9ea3e942011-03-20 14:50:52 +010048 * maintained by the driver model, and is updated using bus notifications.
David Brownell907135a2007-11-15 19:24:01 +010049 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070050struct i2c_dev {
Jean Delvaref3b3aad2006-07-01 17:17:38 +020051 struct list_head list;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 struct i2c_adapter *adap;
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -070053 struct device *dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054};
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
56#define I2C_MINORS 256
Jean Delvaref3b3aad2006-07-01 17:17:38 +020057static LIST_HEAD(i2c_dev_list);
58static DEFINE_SPINLOCK(i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
61{
62 struct i2c_dev *i2c_dev;
63
Jean Delvaref3b3aad2006-07-01 17:17:38 +020064 spin_lock(&i2c_dev_list_lock);
65 list_for_each_entry(i2c_dev, &i2c_dev_list, list) {
66 if (i2c_dev->adap->nr == index)
67 goto found;
68 }
69 i2c_dev = NULL;
70found:
71 spin_unlock(&i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 return i2c_dev;
73}
74
Linus Torvalds1da177e2005-04-16 15:20:36 -070075static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
76{
77 struct i2c_dev *i2c_dev;
78
Jean Delvaref3b3aad2006-07-01 17:17:38 +020079 if (adap->nr >= I2C_MINORS) {
80 printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
81 adap->nr);
82 return ERR_PTR(-ENODEV);
83 }
84
Deepak Saxena5263ebb2005-10-17 23:09:43 +020085 i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 if (!i2c_dev)
87 return ERR_PTR(-ENOMEM);
Jean Delvare9455e4c2006-07-01 17:16:57 +020088 i2c_dev->adap = adap;
Jean Delvaref3b3aad2006-07-01 17:17:38 +020089
90 spin_lock(&i2c_dev_list_lock);
91 list_add_tail(&i2c_dev->list, &i2c_dev_list);
92 spin_unlock(&i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 return i2c_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070094}
95
96static void return_i2c_dev(struct i2c_dev *i2c_dev)
97{
Jean Delvaref3b3aad2006-07-01 17:17:38 +020098 spin_lock(&i2c_dev_list_lock);
99 list_del(&i2c_dev->list);
100 spin_unlock(&i2c_dev_list_lock);
Jean Delvare07125ab2006-12-10 21:21:33 +0100101 kfree(i2c_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102}
103
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700104static ssize_t show_adapter_name(struct device *dev,
105 struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106{
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700107 struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt));
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800108
109 if (!i2c_dev)
110 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 return sprintf(buf, "%s\n", i2c_dev->adap->name);
112}
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700113static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
David Brownell907135a2007-11-15 19:24:01 +0100115/* ------------------------------------------------------------------------- */
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
Farid Hammaneae5624f2010-05-21 18:40:59 +0200134static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count,
135 loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136{
137 char *tmp;
138 int ret;
139
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200140 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
142 if (count > 8192)
143 count = 8192;
144
Farid Hammaneae5624f2010-05-21 18:40:59 +0200145 tmp = kmalloc(count, GFP_KERNEL);
146 if (tmp == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 return -ENOMEM;
148
David Brownell2ce5b342008-08-10 22:56:16 +0200149 pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n",
Josef Sipekcba0a122006-12-08 02:37:08 -0800150 iminor(file->f_path.dentry->d_inode), count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151
Farid Hammaneae5624f2010-05-21 18:40:59 +0200152 ret = i2c_master_recv(client, tmp, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 if (ret >= 0)
Farid Hammaneae5624f2010-05-21 18:40:59 +0200154 ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 kfree(tmp);
156 return ret;
157}
158
Farid Hammaneae5624f2010-05-21 18:40:59 +0200159static ssize_t i2cdev_write(struct file *file, const char __user *buf,
160 size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161{
162 int ret;
163 char *tmp;
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200164 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
166 if (count > 8192)
167 count = 8192;
168
Julia Lawallf1c2e332010-08-11 18:20:55 +0200169 tmp = memdup_user(buf, count);
170 if (IS_ERR(tmp))
171 return PTR_ERR(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172
David Brownell2ce5b342008-08-10 22:56:16 +0200173 pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n",
Josef Sipekcba0a122006-12-08 02:37:08 -0800174 iminor(file->f_path.dentry->d_inode), count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
Farid Hammaneae5624f2010-05-21 18:40:59 +0200176 ret = i2c_master_send(client, tmp, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 kfree(tmp);
178 return ret;
179}
180
David Brownell9b766b82008-01-27 18:14:51 +0100181static int i2cdev_check(struct device *dev, void *addrp)
182{
183 struct i2c_client *client = i2c_verify_client(dev);
184
185 if (!client || client->addr != *(unsigned int *)addrp)
186 return 0;
187
188 return dev->driver ? -EBUSY : 0;
189}
190
Michael Lawnick08263742010-08-11 18:21:02 +0200191/* walk up mux tree */
192static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
193{
Jean Delvare97cc4d42010-10-24 18:16:57 +0200194 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
Michael Lawnick08263742010-08-11 18:21:02 +0200195 int result;
196
197 result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
Jean Delvare97cc4d42010-10-24 18:16:57 +0200198 if (!result && parent)
199 result = i2cdev_check_mux_parents(parent, addr);
Michael Lawnick08263742010-08-11 18:21:02 +0200200
201 return result;
202}
203
204/* recurse down mux tree */
205static int i2cdev_check_mux_children(struct device *dev, void *addrp)
206{
207 int result;
208
209 if (dev->type == &i2c_adapter_type)
210 result = device_for_each_child(dev, addrp,
211 i2cdev_check_mux_children);
212 else
213 result = i2cdev_check(dev, addrp);
214
215 return result;
216}
217
Jean Delvarebd4217d2007-11-15 19:24:01 +0100218/* This address checking function differs from the one in i2c-core
219 in that it considers an address with a registered device, but no
David Brownell9b766b82008-01-27 18:14:51 +0100220 driver bound to it, as NOT busy. */
Jean Delvarebd4217d2007-11-15 19:24:01 +0100221static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
222{
Jean Delvare97cc4d42010-10-24 18:16:57 +0200223 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
Michael Lawnick08263742010-08-11 18:21:02 +0200224 int result = 0;
225
Jean Delvare97cc4d42010-10-24 18:16:57 +0200226 if (parent)
227 result = i2cdev_check_mux_parents(parent, addr);
Michael Lawnick08263742010-08-11 18:21:02 +0200228
229 if (!result)
230 result = device_for_each_child(&adapter->dev, &addr,
231 i2cdev_check_mux_children);
232
233 return result;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100234}
235
Jean Delvaredba79972008-04-22 22:16:47 +0200236static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
237 unsigned long arg)
238{
239 struct i2c_rdwr_ioctl_data rdwr_arg;
240 struct i2c_msg *rdwr_pa;
241 u8 __user **data_ptrs;
242 int i, res;
243
244 if (copy_from_user(&rdwr_arg,
245 (struct i2c_rdwr_ioctl_data __user *)arg,
246 sizeof(rdwr_arg)))
247 return -EFAULT;
248
249 /* Put an arbitrary limit on the number of messages that can
250 * be sent at once */
251 if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
252 return -EINVAL;
253
Joe Perches35a56c52010-08-11 18:20:54 +0200254 rdwr_pa = kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), GFP_KERNEL);
Jean Delvaredba79972008-04-22 22:16:47 +0200255 if (!rdwr_pa)
256 return -ENOMEM;
257
258 if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
259 rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
260 kfree(rdwr_pa);
261 return -EFAULT;
262 }
263
264 data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
265 if (data_ptrs == NULL) {
266 kfree(rdwr_pa);
267 return -ENOMEM;
268 }
269
270 res = 0;
271 for (i = 0; i < rdwr_arg.nmsgs; i++) {
272 /* Limit the size of the message to a sane amount;
273 * and don't let length change either. */
274 if ((rdwr_pa[i].len > 8192) ||
275 (rdwr_pa[i].flags & I2C_M_RECV_LEN)) {
276 res = -EINVAL;
277 break;
278 }
279 data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
Julia Lawallf1c2e332010-08-11 18:20:55 +0200280 rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len);
281 if (IS_ERR(rdwr_pa[i].buf)) {
282 res = PTR_ERR(rdwr_pa[i].buf);
Jean Delvaredba79972008-04-22 22:16:47 +0200283 break;
284 }
285 }
286 if (res < 0) {
287 int j;
288 for (j = 0; j < i; ++j)
289 kfree(rdwr_pa[j].buf);
290 kfree(data_ptrs);
291 kfree(rdwr_pa);
292 return res;
293 }
294
295 res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs);
296 while (i-- > 0) {
297 if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) {
298 if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf,
299 rdwr_pa[i].len))
300 res = -EFAULT;
301 }
302 kfree(rdwr_pa[i].buf);
303 }
304 kfree(data_ptrs);
305 kfree(rdwr_pa);
306 return res;
307}
308
309static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
310 unsigned long arg)
311{
312 struct i2c_smbus_ioctl_data data_arg;
313 union i2c_smbus_data temp;
314 int datasize, res;
315
316 if (copy_from_user(&data_arg,
317 (struct i2c_smbus_ioctl_data __user *) arg,
318 sizeof(struct i2c_smbus_ioctl_data)))
319 return -EFAULT;
320 if ((data_arg.size != I2C_SMBUS_BYTE) &&
321 (data_arg.size != I2C_SMBUS_QUICK) &&
322 (data_arg.size != I2C_SMBUS_BYTE_DATA) &&
323 (data_arg.size != I2C_SMBUS_WORD_DATA) &&
324 (data_arg.size != I2C_SMBUS_PROC_CALL) &&
325 (data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
326 (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
327 (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
328 (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
329 dev_dbg(&client->adapter->dev,
330 "size out of range (%x) in ioctl I2C_SMBUS.\n",
331 data_arg.size);
332 return -EINVAL;
333 }
334 /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
335 so the check is valid if size==I2C_SMBUS_QUICK too. */
336 if ((data_arg.read_write != I2C_SMBUS_READ) &&
337 (data_arg.read_write != I2C_SMBUS_WRITE)) {
338 dev_dbg(&client->adapter->dev,
339 "read_write out of range (%x) in ioctl I2C_SMBUS.\n",
340 data_arg.read_write);
341 return -EINVAL;
342 }
343
344 /* Note that command values are always valid! */
345
346 if ((data_arg.size == I2C_SMBUS_QUICK) ||
347 ((data_arg.size == I2C_SMBUS_BYTE) &&
348 (data_arg.read_write == I2C_SMBUS_WRITE)))
349 /* These are special: we do not use data */
350 return i2c_smbus_xfer(client->adapter, client->addr,
351 client->flags, data_arg.read_write,
352 data_arg.command, data_arg.size, NULL);
353
354 if (data_arg.data == NULL) {
355 dev_dbg(&client->adapter->dev,
356 "data is NULL pointer in ioctl I2C_SMBUS.\n");
357 return -EINVAL;
358 }
359
360 if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
361 (data_arg.size == I2C_SMBUS_BYTE))
362 datasize = sizeof(data_arg.data->byte);
363 else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
364 (data_arg.size == I2C_SMBUS_PROC_CALL))
365 datasize = sizeof(data_arg.data->word);
366 else /* size == smbus block, i2c block, or block proc. call */
367 datasize = sizeof(data_arg.data->block);
368
369 if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
370 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
371 (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
372 (data_arg.read_write == I2C_SMBUS_WRITE)) {
373 if (copy_from_user(&temp, data_arg.data, datasize))
374 return -EFAULT;
375 }
376 if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
377 /* Convert old I2C block commands to the new
378 convention. This preserves binary compatibility. */
379 data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
380 if (data_arg.read_write == I2C_SMBUS_READ)
381 temp.block[0] = I2C_SMBUS_BLOCK_MAX;
382 }
383 res = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
384 data_arg.read_write, data_arg.command, data_arg.size, &temp);
385 if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
386 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
387 (data_arg.read_write == I2C_SMBUS_READ))) {
388 if (copy_to_user(data_arg.data, &temp, datasize))
389 return -EFAULT;
390 }
391 return res;
392}
393
Alan Cox77e38bf2008-07-14 22:38:27 +0200394static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395{
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200396 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397 unsigned long funcs;
398
Jean Delvaree8aafcb2005-10-07 23:06:27 +0200399 dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
400 cmd, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401
Farid Hammaneae5624f2010-05-21 18:40:59 +0200402 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 case I2C_SLAVE:
404 case I2C_SLAVE_FORCE:
David Brownell907135a2007-11-15 19:24:01 +0100405 /* NOTE: devices set up to work with "new style" drivers
406 * can't use I2C_SLAVE, even when the device node is not
407 * bound to a driver. Only I2C_SLAVE_FORCE will work.
408 *
409 * Setting the PEC flag here won't affect kernel drivers,
410 * which will be using the i2c_client node registered with
411 * the driver model core. Likewise, when that client has
412 * the PEC flag already set, the i2c-dev driver won't see
413 * (or use) this setting.
414 */
David Brownell438d6c22006-12-10 21:21:31 +0100415 if ((arg > 0x3ff) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
417 return -EINVAL;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100418 if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 return -EBUSY;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100420 /* REVISIT: address could become busy later */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 client->addr = arg;
422 return 0;
423 case I2C_TENBIT:
424 if (arg)
425 client->flags |= I2C_M_TEN;
426 else
427 client->flags &= ~I2C_M_TEN;
428 return 0;
429 case I2C_PEC:
430 if (arg)
431 client->flags |= I2C_CLIENT_PEC;
432 else
433 client->flags &= ~I2C_CLIENT_PEC;
434 return 0;
435 case I2C_FUNCS:
436 funcs = i2c_get_functionality(client->adapter);
Jean Delvare2c003e82006-12-10 21:21:30 +0100437 return put_user(funcs, (unsigned long __user *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438
439 case I2C_RDWR:
Jean Delvaredba79972008-04-22 22:16:47 +0200440 return i2cdev_ioctl_rdrw(client, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441
442 case I2C_SMBUS:
Jean Delvaredba79972008-04-22 22:16:47 +0200443 return i2cdev_ioctl_smbus(client, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444
David Brownell53be7952007-10-13 23:56:32 +0200445 case I2C_RETRIES:
446 client->adapter->retries = arg;
447 break;
448 case I2C_TIMEOUT:
Jean Delvarecd97f392009-02-24 19:19:49 +0100449 /* For historical reasons, user-space sets the timeout
450 * value in units of 10 ms.
451 */
452 client->adapter->timeout = msecs_to_jiffies(arg * 10);
David Brownell53be7952007-10-13 23:56:32 +0200453 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 default:
David Brownell53be7952007-10-13 23:56:32 +0200455 /* NOTE: returning a fault code here could cause trouble
456 * in buggy userspace code. Some old kernel bugs returned
457 * zero in this case, and userspace code might accidentally
458 * have depended on that bug.
459 */
460 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 }
462 return 0;
463}
464
465static int i2cdev_open(struct inode *inode, struct file *file)
466{
467 unsigned int minor = iminor(inode);
468 struct i2c_client *client;
469 struct i2c_adapter *adap;
470 struct i2c_dev *i2c_dev;
471
472 i2c_dev = i2c_dev_get_by_minor(minor);
Vincent Sanders9669f542009-12-06 17:06:26 +0100473 if (!i2c_dev)
474 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475
476 adap = i2c_get_adapter(i2c_dev->adap->nr);
Vincent Sanders9669f542009-12-06 17:06:26 +0100477 if (!adap)
478 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479
David Brownell907135a2007-11-15 19:24:01 +0100480 /* This creates an anonymous i2c_client, which may later be
481 * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE.
482 *
483 * This client is ** NEVER REGISTERED ** with the driver model
484 * or I2C core code!! It just holds private copies of addressing
485 * information and maybe a PEC flag.
486 */
Jean Delvare22f76e72006-07-01 17:20:57 +0200487 client = kzalloc(sizeof(*client), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 if (!client) {
489 i2c_put_adapter(adap);
Vincent Sanders9669f542009-12-06 17:06:26 +0100490 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 }
Jean Delvare22f76e72006-07-01 17:20:57 +0200492 snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 client->adapter = adap;
495 file->private_data = client;
496
Vincent Sanders9669f542009-12-06 17:06:26 +0100497 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498}
499
500static int i2cdev_release(struct inode *inode, struct file *file)
501{
502 struct i2c_client *client = file->private_data;
503
504 i2c_put_adapter(client->adapter);
505 kfree(client);
506 file->private_data = NULL;
507
508 return 0;
509}
510
Arjan van de Ven2b8693c2007-02-12 00:55:32 -0800511static const struct file_operations i2cdev_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 .owner = THIS_MODULE,
513 .llseek = no_llseek,
514 .read = i2cdev_read,
515 .write = i2cdev_write,
Alan Cox77e38bf2008-07-14 22:38:27 +0200516 .unlocked_ioctl = i2cdev_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 .open = i2cdev_open,
518 .release = i2cdev_release,
519};
520
David Brownell907135a2007-11-15 19:24:01 +0100521/* ------------------------------------------------------------------------- */
522
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800523static struct class *i2c_dev_class;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524
Jean Delvare9ea3e942011-03-20 14:50:52 +0100525static int i2cdev_attach_adapter(struct device *dev, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100527 struct i2c_adapter *adap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 struct i2c_dev *i2c_dev;
Jean Delvaredefcb462006-08-15 18:30:24 +0200529 int res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530
Jean Delvare9ea3e942011-03-20 14:50:52 +0100531 if (dev->type != &i2c_adapter_type)
532 return 0;
533 adap = to_i2c_adapter(dev);
534
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 i2c_dev = get_free_i2c_dev(adap);
536 if (IS_ERR(i2c_dev))
537 return PTR_ERR(i2c_dev);
538
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 /* register this i2c device with the driver core */
Greg Kroah-Hartmana9b12612008-07-21 20:03:34 -0700540 i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
541 MKDEV(I2C_MAJOR, adap->nr), NULL,
542 "i2c-%d", adap->nr);
Akinobu Mita3bacb362006-12-10 21:21:33 +0100543 if (IS_ERR(i2c_dev->dev)) {
544 res = PTR_ERR(i2c_dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 goto error;
Jean Delvaredefcb462006-08-15 18:30:24 +0200546 }
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700547 res = device_create_file(i2c_dev->dev, &dev_attr_name);
Jean Delvaredefcb462006-08-15 18:30:24 +0200548 if (res)
549 goto error_destroy;
Jean Delvareb32d20d2006-09-03 22:19:25 +0200550
551 pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
552 adap->name, adap->nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 return 0;
Jean Delvaredefcb462006-08-15 18:30:24 +0200554error_destroy:
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700555 device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556error:
557 return_i2c_dev(i2c_dev);
Jean Delvaredefcb462006-08-15 18:30:24 +0200558 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559}
560
Jean Delvare9ea3e942011-03-20 14:50:52 +0100561static int i2cdev_detach_adapter(struct device *dev, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100563 struct i2c_adapter *adap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 struct i2c_dev *i2c_dev;
565
Jean Delvare9ea3e942011-03-20 14:50:52 +0100566 if (dev->type != &i2c_adapter_type)
567 return 0;
568 adap = to_i2c_adapter(dev);
569
Jean Delvare9455e4c2006-07-01 17:16:57 +0200570 i2c_dev = i2c_dev_get_by_minor(adap->nr);
Jean Delvareb32d20d2006-09-03 22:19:25 +0200571 if (!i2c_dev) /* attach_adapter must have failed */
572 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700574 device_remove_file(i2c_dev->dev, &dev_attr_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 return_i2c_dev(i2c_dev);
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700576 device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577
Jean Delvareb6d7b3d2005-07-31 19:02:53 +0200578 pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 return 0;
580}
581
Jean Delvare9ea3e942011-03-20 14:50:52 +0100582int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action,
583 void *data)
584{
585 struct device *dev = data;
586
587 switch (action) {
588 case BUS_NOTIFY_ADD_DEVICE:
589 return i2cdev_attach_adapter(dev, NULL);
590 case BUS_NOTIFY_DEL_DEVICE:
591 return i2cdev_detach_adapter(dev, NULL);
592 }
593
594 return 0;
595}
596
597static struct notifier_block i2cdev_notifier = {
598 .notifier_call = i2cdev_notifier_call,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599};
600
David Brownell907135a2007-11-15 19:24:01 +0100601/* ------------------------------------------------------------------------- */
602
603/*
604 * module load/unload record keeping
605 */
606
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607static int __init i2c_dev_init(void)
608{
609 int res;
610
611 printk(KERN_INFO "i2c /dev entries driver\n");
612
613 res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops);
614 if (res)
615 goto out;
616
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800617 i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
Sven Wegenere74783e2008-09-24 13:39:21 +0200618 if (IS_ERR(i2c_dev_class)) {
619 res = PTR_ERR(i2c_dev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 goto out_unreg_chrdev;
Sven Wegenere74783e2008-09-24 13:39:21 +0200621 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622
Jean Delvare9ea3e942011-03-20 14:50:52 +0100623 /* Keep track of adapters which will be added or removed later */
624 res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 if (res)
626 goto out_unreg_class;
627
Jean Delvare9ea3e942011-03-20 14:50:52 +0100628 /* Bind to already existing adapters right away */
629 i2c_for_each_dev(NULL, i2cdev_attach_adapter);
630
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 return 0;
632
633out_unreg_class:
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800634 class_destroy(i2c_dev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635out_unreg_chrdev:
636 unregister_chrdev(I2C_MAJOR, "i2c");
637out:
638 printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
639 return res;
640}
641
642static void __exit i2c_dev_exit(void)
643{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100644 bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier);
645 i2c_for_each_dev(NULL, i2cdev_detach_adapter);
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800646 class_destroy(i2c_dev_class);
Farid Hammaneae5624f2010-05-21 18:40:59 +0200647 unregister_chrdev(I2C_MAJOR, "i2c");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648}
649
650MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
651 "Simon G. Vogl <simon@tk.uni-linz.ac.at>");
652MODULE_DESCRIPTION("I2C /dev entries driver");
653MODULE_LICENSE("GPL");
654
655module_init(i2c_dev_init);
656module_exit(i2c_dev_exit);