blob: 2413ec9f8207eeffcfbeeb5480043e4651fdf15a [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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070017*/
18
19/* Note that this is a complete rewrite of Simon Vogl's i2c-dev module.
20 But I have used so much of his original code and ideas that it seems
21 only fair to recognize him as co-author -- Frodo */
22
23/* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */
24
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/kernel.h>
26#include <linux/module.h>
Jean Delvare9ea3e942011-03-20 14:50:52 +010027#include <linux/device.h>
28#include <linux/notifier.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <linux/fs.h>
30#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <linux/init.h>
Jean Delvaref3b3aad2006-07-01 17:17:38 +020032#include <linux/list.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/i2c.h>
34#include <linux/i2c-dev.h>
Jean Delvarecd97f392009-02-24 19:19:49 +010035#include <linux/jiffies.h>
Farid Hammaneae5624f2010-05-21 18:40:59 +020036#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
David Brownell907135a2007-11-15 19:24:01 +010038/*
39 * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a
40 * slave (i2c_client) with which messages will be exchanged. It's coupled
41 * with a character special file which is accessed by user mode drivers.
42 *
43 * The list of i2c_dev structures is parallel to the i2c_adapter lists
Jean Delvare9ea3e942011-03-20 14:50:52 +010044 * maintained by the driver model, and is updated using bus notifications.
David Brownell907135a2007-11-15 19:24:01 +010045 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070046struct i2c_dev {
Jean Delvaref3b3aad2006-07-01 17:17:38 +020047 struct list_head list;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 struct i2c_adapter *adap;
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -070049 struct device *dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070050};
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
52#define I2C_MINORS 256
Jean Delvaref3b3aad2006-07-01 17:17:38 +020053static LIST_HEAD(i2c_dev_list);
54static DEFINE_SPINLOCK(i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
56static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
57{
58 struct i2c_dev *i2c_dev;
59
Jean Delvaref3b3aad2006-07-01 17:17:38 +020060 spin_lock(&i2c_dev_list_lock);
61 list_for_each_entry(i2c_dev, &i2c_dev_list, list) {
62 if (i2c_dev->adap->nr == index)
63 goto found;
64 }
65 i2c_dev = NULL;
66found:
67 spin_unlock(&i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 return i2c_dev;
69}
70
Linus Torvalds1da177e2005-04-16 15:20:36 -070071static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
72{
73 struct i2c_dev *i2c_dev;
74
Jean Delvaref3b3aad2006-07-01 17:17:38 +020075 if (adap->nr >= I2C_MINORS) {
76 printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
77 adap->nr);
78 return ERR_PTR(-ENODEV);
79 }
80
Deepak Saxena5263ebb2005-10-17 23:09:43 +020081 i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 if (!i2c_dev)
83 return ERR_PTR(-ENOMEM);
Jean Delvare9455e4c2006-07-01 17:16:57 +020084 i2c_dev->adap = adap;
Jean Delvaref3b3aad2006-07-01 17:17:38 +020085
86 spin_lock(&i2c_dev_list_lock);
87 list_add_tail(&i2c_dev->list, &i2c_dev_list);
88 spin_unlock(&i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 return i2c_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090}
91
92static void return_i2c_dev(struct i2c_dev *i2c_dev)
93{
Jean Delvaref3b3aad2006-07-01 17:17:38 +020094 spin_lock(&i2c_dev_list_lock);
95 list_del(&i2c_dev->list);
96 spin_unlock(&i2c_dev_list_lock);
Jean Delvare07125ab2006-12-10 21:21:33 +010097 kfree(i2c_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098}
99
Guenter Roeck45f176a2013-09-26 19:36:11 -0700100static ssize_t name_show(struct device *dev,
101 struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102{
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700103 struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt));
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800104
105 if (!i2c_dev)
106 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 return sprintf(buf, "%s\n", i2c_dev->adap->name);
108}
Guenter Roeck45f176a2013-09-26 19:36:11 -0700109static DEVICE_ATTR_RO(name);
110
111static struct attribute *i2c_attrs[] = {
112 &dev_attr_name.attr,
113 NULL,
114};
115ATTRIBUTE_GROUPS(i2c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
David Brownell907135a2007-11-15 19:24:01 +0100117/* ------------------------------------------------------------------------- */
118
119/*
120 * After opening an instance of this character special file, a file
121 * descriptor starts out associated only with an i2c_adapter (and bus).
122 *
123 * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg
124 * traffic to any devices on the bus used by that adapter. That's because
125 * the i2c_msg vectors embed all the addressing information they need, and
126 * are submitted directly to an i2c_adapter. However, SMBus-only adapters
127 * don't support that interface.
128 *
129 * To use read()/write() system calls on that file descriptor, or to use
130 * SMBus interfaces (and work with SMBus-only hosts!), you must first issue
131 * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous
132 * (never registered) i2c_client so it holds the addressing information
133 * needed by those system calls and by this SMBus interface.
134 */
135
Farid Hammaneae5624f2010-05-21 18:40:59 +0200136static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count,
137 loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138{
139 char *tmp;
140 int ret;
141
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200142 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
144 if (count > 8192)
145 count = 8192;
146
Farid Hammaneae5624f2010-05-21 18:40:59 +0200147 tmp = kmalloc(count, GFP_KERNEL);
148 if (tmp == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 return -ENOMEM;
150
David Brownell2ce5b342008-08-10 22:56:16 +0200151 pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n",
Al Viro496ad9a2013-01-23 17:07:38 -0500152 iminor(file_inode(file)), count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
Farid Hammaneae5624f2010-05-21 18:40:59 +0200154 ret = i2c_master_recv(client, tmp, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 if (ret >= 0)
Farid Hammaneae5624f2010-05-21 18:40:59 +0200156 ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 kfree(tmp);
158 return ret;
159}
160
Farid Hammaneae5624f2010-05-21 18:40:59 +0200161static ssize_t i2cdev_write(struct file *file, const char __user *buf,
162 size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163{
164 int ret;
165 char *tmp;
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200166 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
168 if (count > 8192)
169 count = 8192;
170
Julia Lawallf1c2e332010-08-11 18:20:55 +0200171 tmp = memdup_user(buf, count);
172 if (IS_ERR(tmp))
173 return PTR_ERR(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174
David Brownell2ce5b342008-08-10 22:56:16 +0200175 pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n",
Al Viro496ad9a2013-01-23 17:07:38 -0500176 iminor(file_inode(file)), count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177
Farid Hammaneae5624f2010-05-21 18:40:59 +0200178 ret = i2c_master_send(client, tmp, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 kfree(tmp);
180 return ret;
181}
182
David Brownell9b766b82008-01-27 18:14:51 +0100183static int i2cdev_check(struct device *dev, void *addrp)
184{
185 struct i2c_client *client = i2c_verify_client(dev);
186
187 if (!client || client->addr != *(unsigned int *)addrp)
188 return 0;
189
190 return dev->driver ? -EBUSY : 0;
191}
192
Michael Lawnick08263742010-08-11 18:21:02 +0200193/* walk up mux tree */
194static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
195{
Jean Delvare97cc4d42010-10-24 18:16:57 +0200196 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
Michael Lawnick08263742010-08-11 18:21:02 +0200197 int result;
198
199 result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
Jean Delvare97cc4d42010-10-24 18:16:57 +0200200 if (!result && parent)
201 result = i2cdev_check_mux_parents(parent, addr);
Michael Lawnick08263742010-08-11 18:21:02 +0200202
203 return result;
204}
205
206/* recurse down mux tree */
207static int i2cdev_check_mux_children(struct device *dev, void *addrp)
208{
209 int result;
210
211 if (dev->type == &i2c_adapter_type)
212 result = device_for_each_child(dev, addrp,
213 i2cdev_check_mux_children);
214 else
215 result = i2cdev_check(dev, addrp);
216
217 return result;
218}
219
Jean Delvarebd4217d2007-11-15 19:24:01 +0100220/* This address checking function differs from the one in i2c-core
221 in that it considers an address with a registered device, but no
David Brownell9b766b82008-01-27 18:14:51 +0100222 driver bound to it, as NOT busy. */
Jean Delvarebd4217d2007-11-15 19:24:01 +0100223static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
224{
Jean Delvare97cc4d42010-10-24 18:16:57 +0200225 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
Michael Lawnick08263742010-08-11 18:21:02 +0200226 int result = 0;
227
Jean Delvare97cc4d42010-10-24 18:16:57 +0200228 if (parent)
229 result = i2cdev_check_mux_parents(parent, addr);
Michael Lawnick08263742010-08-11 18:21:02 +0200230
231 if (!result)
232 result = device_for_each_child(&adapter->dev, &addr,
233 i2cdev_check_mux_children);
234
235 return result;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100236}
237
Jean Delvarec57d3e72015-09-08 11:05:49 +0200238static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client,
Jean Delvaredba79972008-04-22 22:16:47 +0200239 unsigned long arg)
240{
241 struct i2c_rdwr_ioctl_data rdwr_arg;
242 struct i2c_msg *rdwr_pa;
243 u8 __user **data_ptrs;
244 int i, res;
245
246 if (copy_from_user(&rdwr_arg,
247 (struct i2c_rdwr_ioctl_data __user *)arg,
248 sizeof(rdwr_arg)))
249 return -EFAULT;
250
251 /* Put an arbitrary limit on the number of messages that can
252 * be sent at once */
Jean Delvarec57d3e72015-09-08 11:05:49 +0200253 if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS)
Jean Delvaredba79972008-04-22 22:16:47 +0200254 return -EINVAL;
255
Thomas Meyera699ed6f2012-01-12 20:32:04 +0100256 rdwr_pa = memdup_user(rdwr_arg.msgs,
257 rdwr_arg.nmsgs * sizeof(struct i2c_msg));
258 if (IS_ERR(rdwr_pa))
259 return PTR_ERR(rdwr_pa);
Jean Delvaredba79972008-04-22 22:16:47 +0200260
261 data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
262 if (data_ptrs == NULL) {
263 kfree(rdwr_pa);
264 return -ENOMEM;
265 }
266
267 res = 0;
268 for (i = 0; i < rdwr_arg.nmsgs; i++) {
Jean Delvare838bfa62012-05-30 10:55:34 +0200269 /* Limit the size of the message to a sane amount */
270 if (rdwr_pa[i].len > 8192) {
Jean Delvaredba79972008-04-22 22:16:47 +0200271 res = -EINVAL;
272 break;
273 }
Jean Delvare838bfa62012-05-30 10:55:34 +0200274
Jean Delvaredba79972008-04-22 22:16:47 +0200275 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 }
Jean Delvare838bfa62012-05-30 10:55:34 +0200281
282 /*
283 * If the message length is received from the slave (similar
284 * to SMBus block read), we must ensure that the buffer will
285 * be large enough to cope with a message length of
286 * I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus
287 * drivers allow. The first byte in the buffer must be
288 * pre-filled with the number of extra bytes, which must be
289 * at least one to hold the message length, but can be
290 * greater (for example to account for a checksum byte at
291 * the end of the message.)
292 */
293 if (rdwr_pa[i].flags & I2C_M_RECV_LEN) {
294 if (!(rdwr_pa[i].flags & I2C_M_RD) ||
295 rdwr_pa[i].buf[0] < 1 ||
296 rdwr_pa[i].len < rdwr_pa[i].buf[0] +
297 I2C_SMBUS_BLOCK_MAX) {
298 res = -EINVAL;
299 break;
300 }
301
302 rdwr_pa[i].len = rdwr_pa[i].buf[0];
303 }
Jean Delvaredba79972008-04-22 22:16:47 +0200304 }
305 if (res < 0) {
306 int j;
307 for (j = 0; j < i; ++j)
308 kfree(rdwr_pa[j].buf);
309 kfree(data_ptrs);
310 kfree(rdwr_pa);
311 return res;
312 }
313
314 res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs);
315 while (i-- > 0) {
316 if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) {
317 if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf,
318 rdwr_pa[i].len))
319 res = -EFAULT;
320 }
321 kfree(rdwr_pa[i].buf);
322 }
323 kfree(data_ptrs);
324 kfree(rdwr_pa);
325 return res;
326}
327
328static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
329 unsigned long arg)
330{
331 struct i2c_smbus_ioctl_data data_arg;
332 union i2c_smbus_data temp;
333 int datasize, res;
334
335 if (copy_from_user(&data_arg,
336 (struct i2c_smbus_ioctl_data __user *) arg,
337 sizeof(struct i2c_smbus_ioctl_data)))
338 return -EFAULT;
339 if ((data_arg.size != I2C_SMBUS_BYTE) &&
340 (data_arg.size != I2C_SMBUS_QUICK) &&
341 (data_arg.size != I2C_SMBUS_BYTE_DATA) &&
342 (data_arg.size != I2C_SMBUS_WORD_DATA) &&
343 (data_arg.size != I2C_SMBUS_PROC_CALL) &&
344 (data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
345 (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
346 (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
347 (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
348 dev_dbg(&client->adapter->dev,
349 "size out of range (%x) in ioctl I2C_SMBUS.\n",
350 data_arg.size);
351 return -EINVAL;
352 }
353 /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
354 so the check is valid if size==I2C_SMBUS_QUICK too. */
355 if ((data_arg.read_write != I2C_SMBUS_READ) &&
356 (data_arg.read_write != I2C_SMBUS_WRITE)) {
357 dev_dbg(&client->adapter->dev,
358 "read_write out of range (%x) in ioctl I2C_SMBUS.\n",
359 data_arg.read_write);
360 return -EINVAL;
361 }
362
363 /* Note that command values are always valid! */
364
365 if ((data_arg.size == I2C_SMBUS_QUICK) ||
366 ((data_arg.size == I2C_SMBUS_BYTE) &&
367 (data_arg.read_write == I2C_SMBUS_WRITE)))
368 /* These are special: we do not use data */
369 return i2c_smbus_xfer(client->adapter, client->addr,
370 client->flags, data_arg.read_write,
371 data_arg.command, data_arg.size, NULL);
372
373 if (data_arg.data == NULL) {
374 dev_dbg(&client->adapter->dev,
375 "data is NULL pointer in ioctl I2C_SMBUS.\n");
376 return -EINVAL;
377 }
378
379 if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
380 (data_arg.size == I2C_SMBUS_BYTE))
381 datasize = sizeof(data_arg.data->byte);
382 else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
383 (data_arg.size == I2C_SMBUS_PROC_CALL))
384 datasize = sizeof(data_arg.data->word);
385 else /* size == smbus block, i2c block, or block proc. call */
386 datasize = sizeof(data_arg.data->block);
387
388 if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
389 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
390 (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
391 (data_arg.read_write == I2C_SMBUS_WRITE)) {
392 if (copy_from_user(&temp, data_arg.data, datasize))
393 return -EFAULT;
394 }
395 if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
396 /* Convert old I2C block commands to the new
397 convention. This preserves binary compatibility. */
398 data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
399 if (data_arg.read_write == I2C_SMBUS_READ)
400 temp.block[0] = I2C_SMBUS_BLOCK_MAX;
401 }
402 res = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
403 data_arg.read_write, data_arg.command, data_arg.size, &temp);
404 if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
405 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
406 (data_arg.read_write == I2C_SMBUS_READ))) {
407 if (copy_to_user(data_arg.data, &temp, datasize))
408 return -EFAULT;
409 }
410 return res;
411}
412
Alan Cox77e38bf2008-07-14 22:38:27 +0200413static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414{
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200415 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 unsigned long funcs;
417
Jean Delvaree8aafcb2005-10-07 23:06:27 +0200418 dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
419 cmd, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420
Farid Hammaneae5624f2010-05-21 18:40:59 +0200421 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 case I2C_SLAVE:
423 case I2C_SLAVE_FORCE:
David Brownell438d6c22006-12-10 21:21:31 +0100424 if ((arg > 0x3ff) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
426 return -EINVAL;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100427 if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 return -EBUSY;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100429 /* REVISIT: address could become busy later */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 client->addr = arg;
431 return 0;
432 case I2C_TENBIT:
433 if (arg)
434 client->flags |= I2C_M_TEN;
435 else
436 client->flags &= ~I2C_M_TEN;
437 return 0;
438 case I2C_PEC:
Jean Delvare9e685c82015-09-11 11:27:18 +0200439 /*
440 * Setting the PEC flag here won't affect kernel drivers,
441 * which will be using the i2c_client node registered with
442 * the driver model core. Likewise, when that client has
443 * the PEC flag already set, the i2c-dev driver won't see
444 * (or use) this setting.
445 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 if (arg)
447 client->flags |= I2C_CLIENT_PEC;
448 else
449 client->flags &= ~I2C_CLIENT_PEC;
450 return 0;
451 case I2C_FUNCS:
452 funcs = i2c_get_functionality(client->adapter);
Jean Delvare2c003e82006-12-10 21:21:30 +0100453 return put_user(funcs, (unsigned long __user *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454
455 case I2C_RDWR:
Jean Delvarec57d3e72015-09-08 11:05:49 +0200456 return i2cdev_ioctl_rdwr(client, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457
458 case I2C_SMBUS:
Jean Delvaredba79972008-04-22 22:16:47 +0200459 return i2cdev_ioctl_smbus(client, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460
David Brownell53be7952007-10-13 23:56:32 +0200461 case I2C_RETRIES:
462 client->adapter->retries = arg;
463 break;
464 case I2C_TIMEOUT:
Jean Delvarecd97f392009-02-24 19:19:49 +0100465 /* For historical reasons, user-space sets the timeout
466 * value in units of 10 ms.
467 */
468 client->adapter->timeout = msecs_to_jiffies(arg * 10);
David Brownell53be7952007-10-13 23:56:32 +0200469 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 default:
David Brownell53be7952007-10-13 23:56:32 +0200471 /* NOTE: returning a fault code here could cause trouble
472 * in buggy userspace code. Some old kernel bugs returned
473 * zero in this case, and userspace code might accidentally
474 * have depended on that bug.
475 */
476 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 }
478 return 0;
479}
480
481static int i2cdev_open(struct inode *inode, struct file *file)
482{
483 unsigned int minor = iminor(inode);
484 struct i2c_client *client;
485 struct i2c_adapter *adap;
486 struct i2c_dev *i2c_dev;
487
488 i2c_dev = i2c_dev_get_by_minor(minor);
Vincent Sanders9669f542009-12-06 17:06:26 +0100489 if (!i2c_dev)
490 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491
492 adap = i2c_get_adapter(i2c_dev->adap->nr);
Vincent Sanders9669f542009-12-06 17:06:26 +0100493 if (!adap)
494 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495
David Brownell907135a2007-11-15 19:24:01 +0100496 /* This creates an anonymous i2c_client, which may later be
497 * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE.
498 *
499 * This client is ** NEVER REGISTERED ** with the driver model
500 * or I2C core code!! It just holds private copies of addressing
501 * information and maybe a PEC flag.
502 */
Jean Delvare22f76e72006-07-01 17:20:57 +0200503 client = kzalloc(sizeof(*client), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 if (!client) {
505 i2c_put_adapter(adap);
Vincent Sanders9669f542009-12-06 17:06:26 +0100506 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 }
Jean Delvare22f76e72006-07-01 17:20:57 +0200508 snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 client->adapter = adap;
511 file->private_data = client;
512
Vincent Sanders9669f542009-12-06 17:06:26 +0100513 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514}
515
516static int i2cdev_release(struct inode *inode, struct file *file)
517{
518 struct i2c_client *client = file->private_data;
519
520 i2c_put_adapter(client->adapter);
521 kfree(client);
522 file->private_data = NULL;
523
524 return 0;
525}
526
Arjan van de Ven2b8693c2007-02-12 00:55:32 -0800527static const struct file_operations i2cdev_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 .owner = THIS_MODULE,
529 .llseek = no_llseek,
530 .read = i2cdev_read,
531 .write = i2cdev_write,
Alan Cox77e38bf2008-07-14 22:38:27 +0200532 .unlocked_ioctl = i2cdev_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 .open = i2cdev_open,
534 .release = i2cdev_release,
535};
536
David Brownell907135a2007-11-15 19:24:01 +0100537/* ------------------------------------------------------------------------- */
538
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800539static struct class *i2c_dev_class;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540
Jean Delvare9ea3e942011-03-20 14:50:52 +0100541static int i2cdev_attach_adapter(struct device *dev, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100543 struct i2c_adapter *adap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 struct i2c_dev *i2c_dev;
Jean Delvaredefcb462006-08-15 18:30:24 +0200545 int res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546
Jean Delvare9ea3e942011-03-20 14:50:52 +0100547 if (dev->type != &i2c_adapter_type)
548 return 0;
549 adap = to_i2c_adapter(dev);
550
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 i2c_dev = get_free_i2c_dev(adap);
552 if (IS_ERR(i2c_dev))
553 return PTR_ERR(i2c_dev);
554
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 /* register this i2c device with the driver core */
Greg Kroah-Hartmana9b12612008-07-21 20:03:34 -0700556 i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
557 MKDEV(I2C_MAJOR, adap->nr), NULL,
558 "i2c-%d", adap->nr);
Akinobu Mita3bacb362006-12-10 21:21:33 +0100559 if (IS_ERR(i2c_dev->dev)) {
560 res = PTR_ERR(i2c_dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 goto error;
Jean Delvaredefcb462006-08-15 18:30:24 +0200562 }
Jean Delvareb32d20d2006-09-03 22:19:25 +0200563
564 pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
565 adap->name, adap->nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 return 0;
567error:
568 return_i2c_dev(i2c_dev);
Jean Delvaredefcb462006-08-15 18:30:24 +0200569 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570}
571
Jean Delvare9ea3e942011-03-20 14:50:52 +0100572static int i2cdev_detach_adapter(struct device *dev, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100574 struct i2c_adapter *adap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 struct i2c_dev *i2c_dev;
576
Jean Delvare9ea3e942011-03-20 14:50:52 +0100577 if (dev->type != &i2c_adapter_type)
578 return 0;
579 adap = to_i2c_adapter(dev);
580
Jean Delvare9455e4c2006-07-01 17:16:57 +0200581 i2c_dev = i2c_dev_get_by_minor(adap->nr);
Jean Delvareb32d20d2006-09-03 22:19:25 +0200582 if (!i2c_dev) /* attach_adapter must have failed */
583 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 return_i2c_dev(i2c_dev);
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700586 device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587
Jean Delvareb6d7b3d2005-07-31 19:02:53 +0200588 pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 return 0;
590}
591
Shubhrajyoti Deff245c2011-11-23 11:33:07 +0100592static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action,
Jean Delvare9ea3e942011-03-20 14:50:52 +0100593 void *data)
594{
595 struct device *dev = data;
596
597 switch (action) {
598 case BUS_NOTIFY_ADD_DEVICE:
599 return i2cdev_attach_adapter(dev, NULL);
600 case BUS_NOTIFY_DEL_DEVICE:
601 return i2cdev_detach_adapter(dev, NULL);
602 }
603
604 return 0;
605}
606
607static struct notifier_block i2cdev_notifier = {
608 .notifier_call = i2cdev_notifier_call,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609};
610
David Brownell907135a2007-11-15 19:24:01 +0100611/* ------------------------------------------------------------------------- */
612
613/*
614 * module load/unload record keeping
615 */
616
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617static int __init i2c_dev_init(void)
618{
619 int res;
620
621 printk(KERN_INFO "i2c /dev entries driver\n");
622
623 res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops);
624 if (res)
625 goto out;
626
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800627 i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
Sven Wegenere74783e2008-09-24 13:39:21 +0200628 if (IS_ERR(i2c_dev_class)) {
629 res = PTR_ERR(i2c_dev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 goto out_unreg_chrdev;
Sven Wegenere74783e2008-09-24 13:39:21 +0200631 }
Guenter Roeck45f176a2013-09-26 19:36:11 -0700632 i2c_dev_class->dev_groups = i2c_groups;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633
Jean Delvare9ea3e942011-03-20 14:50:52 +0100634 /* Keep track of adapters which will be added or removed later */
635 res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 if (res)
637 goto out_unreg_class;
638
Jean Delvare9ea3e942011-03-20 14:50:52 +0100639 /* Bind to already existing adapters right away */
640 i2c_for_each_dev(NULL, i2cdev_attach_adapter);
641
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 return 0;
643
644out_unreg_class:
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800645 class_destroy(i2c_dev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646out_unreg_chrdev:
647 unregister_chrdev(I2C_MAJOR, "i2c");
648out:
649 printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
650 return res;
651}
652
653static void __exit i2c_dev_exit(void)
654{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100655 bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier);
656 i2c_for_each_dev(NULL, i2cdev_detach_adapter);
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800657 class_destroy(i2c_dev_class);
Farid Hammaneae5624f2010-05-21 18:40:59 +0200658 unregister_chrdev(I2C_MAJOR, "i2c");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659}
660
661MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
662 "Simon G. Vogl <simon@tk.uni-linz.ac.at>");
663MODULE_DESCRIPTION("I2C /dev entries driver");
664MODULE_LICENSE("GPL");
665
666module_init(i2c_dev_init);
667module_exit(i2c_dev_exit);