blob: 66f323fd39826ebe9a738d55724ee2e124b45419 [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
Erico Nunesd6760b12016-05-03 15:45:43 -030025#include <linux/cdev.h>
Jean Delvare9ea3e942011-03-20 14:50:52 +010026#include <linux/device.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/i2c-dev.h>
Wolfram Sanga8766072016-02-20 23:33:38 +010029#include <linux/i2c.h>
30#include <linux/init.h>
Jean Delvarecd97f392009-02-24 19:19:49 +010031#include <linux/jiffies.h>
Wolfram Sanga8766072016-02-20 23:33:38 +010032#include <linux/kernel.h>
33#include <linux/list.h>
34#include <linux/module.h>
35#include <linux/notifier.h>
36#include <linux/slab.h>
Farid Hammaneae5624f2010-05-21 18:40:59 +020037#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
David Brownell907135a2007-11-15 19:24:01 +010039/*
40 * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a
41 * slave (i2c_client) with which messages will be exchanged. It's coupled
42 * with a character special file which is accessed by user mode drivers.
43 *
44 * The list of i2c_dev structures is parallel to the i2c_adapter lists
Jean Delvare9ea3e942011-03-20 14:50:52 +010045 * maintained by the driver model, and is updated using bus notifications.
David Brownell907135a2007-11-15 19:24:01 +010046 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070047struct i2c_dev {
Jean Delvaref3b3aad2006-07-01 17:17:38 +020048 struct list_head list;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 struct i2c_adapter *adap;
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -070050 struct device *dev;
Erico Nunesd6760b12016-05-03 15:45:43 -030051 struct cdev cdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052};
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
Erico Nunesd6760b12016-05-03 15:45:43 -030054#define I2C_MINORS MINORMASK
Jean Delvaref3b3aad2006-07-01 17:17:38 +020055static LIST_HEAD(i2c_dev_list);
56static DEFINE_SPINLOCK(i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
58static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
59{
60 struct i2c_dev *i2c_dev;
61
Jean Delvaref3b3aad2006-07-01 17:17:38 +020062 spin_lock(&i2c_dev_list_lock);
63 list_for_each_entry(i2c_dev, &i2c_dev_list, list) {
64 if (i2c_dev->adap->nr == index)
65 goto found;
66 }
67 i2c_dev = NULL;
68found:
69 spin_unlock(&i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 return i2c_dev;
71}
72
Linus Torvalds1da177e2005-04-16 15:20:36 -070073static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
74{
75 struct i2c_dev *i2c_dev;
76
Jean Delvaref3b3aad2006-07-01 17:17:38 +020077 if (adap->nr >= I2C_MINORS) {
78 printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
79 adap->nr);
80 return ERR_PTR(-ENODEV);
81 }
82
Deepak Saxena5263ebb2005-10-17 23:09:43 +020083 i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 if (!i2c_dev)
85 return ERR_PTR(-ENOMEM);
Jean Delvare9455e4c2006-07-01 17:16:57 +020086 i2c_dev->adap = adap;
Jean Delvaref3b3aad2006-07-01 17:17:38 +020087
88 spin_lock(&i2c_dev_list_lock);
89 list_add_tail(&i2c_dev->list, &i2c_dev_list);
90 spin_unlock(&i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 return i2c_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070092}
93
Wolfram Sang72a71f82016-05-27 13:13:01 +020094static void put_i2c_dev(struct i2c_dev *i2c_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070095{
Jean Delvaref3b3aad2006-07-01 17:17:38 +020096 spin_lock(&i2c_dev_list_lock);
97 list_del(&i2c_dev->list);
98 spin_unlock(&i2c_dev_list_lock);
Jean Delvare07125ab2006-12-10 21:21:33 +010099 kfree(i2c_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100}
101
Guenter Roeck45f176a2013-09-26 19:36:11 -0700102static ssize_t name_show(struct device *dev,
103 struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104{
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700105 struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt));
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800106
107 if (!i2c_dev)
108 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 return sprintf(buf, "%s\n", i2c_dev->adap->name);
110}
Guenter Roeck45f176a2013-09-26 19:36:11 -0700111static DEVICE_ATTR_RO(name);
112
113static struct attribute *i2c_attrs[] = {
114 &dev_attr_name.attr,
115 NULL,
116};
117ATTRIBUTE_GROUPS(i2c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
David Brownell907135a2007-11-15 19:24:01 +0100119/* ------------------------------------------------------------------------- */
120
121/*
122 * After opening an instance of this character special file, a file
123 * descriptor starts out associated only with an i2c_adapter (and bus).
124 *
125 * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg
126 * traffic to any devices on the bus used by that adapter. That's because
127 * the i2c_msg vectors embed all the addressing information they need, and
128 * are submitted directly to an i2c_adapter. However, SMBus-only adapters
129 * don't support that interface.
130 *
131 * To use read()/write() system calls on that file descriptor, or to use
132 * SMBus interfaces (and work with SMBus-only hosts!), you must first issue
133 * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous
134 * (never registered) i2c_client so it holds the addressing information
135 * needed by those system calls and by this SMBus interface.
136 */
137
Farid Hammaneae5624f2010-05-21 18:40:59 +0200138static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count,
139 loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140{
141 char *tmp;
142 int ret;
143
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200144 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
146 if (count > 8192)
147 count = 8192;
148
Farid Hammaneae5624f2010-05-21 18:40:59 +0200149 tmp = kmalloc(count, GFP_KERNEL);
150 if (tmp == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 return -ENOMEM;
152
David Brownell2ce5b342008-08-10 22:56:16 +0200153 pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n",
Al Viro496ad9a2013-01-23 17:07:38 -0500154 iminor(file_inode(file)), count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
Farid Hammaneae5624f2010-05-21 18:40:59 +0200156 ret = i2c_master_recv(client, tmp, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 if (ret >= 0)
Farid Hammaneae5624f2010-05-21 18:40:59 +0200158 ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 kfree(tmp);
160 return ret;
161}
162
Farid Hammaneae5624f2010-05-21 18:40:59 +0200163static ssize_t i2cdev_write(struct file *file, const char __user *buf,
164 size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165{
166 int ret;
167 char *tmp;
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200168 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
170 if (count > 8192)
171 count = 8192;
172
Julia Lawallf1c2e332010-08-11 18:20:55 +0200173 tmp = memdup_user(buf, count);
174 if (IS_ERR(tmp))
175 return PTR_ERR(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
David Brownell2ce5b342008-08-10 22:56:16 +0200177 pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n",
Al Viro496ad9a2013-01-23 17:07:38 -0500178 iminor(file_inode(file)), count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179
Farid Hammaneae5624f2010-05-21 18:40:59 +0200180 ret = i2c_master_send(client, tmp, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 kfree(tmp);
182 return ret;
183}
184
David Brownell9b766b82008-01-27 18:14:51 +0100185static int i2cdev_check(struct device *dev, void *addrp)
186{
187 struct i2c_client *client = i2c_verify_client(dev);
188
189 if (!client || client->addr != *(unsigned int *)addrp)
190 return 0;
191
192 return dev->driver ? -EBUSY : 0;
193}
194
Michael Lawnick08263742010-08-11 18:21:02 +0200195/* walk up mux tree */
196static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
197{
Jean Delvare97cc4d42010-10-24 18:16:57 +0200198 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
Michael Lawnick08263742010-08-11 18:21:02 +0200199 int result;
200
201 result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
Jean Delvare97cc4d42010-10-24 18:16:57 +0200202 if (!result && parent)
203 result = i2cdev_check_mux_parents(parent, addr);
Michael Lawnick08263742010-08-11 18:21:02 +0200204
205 return result;
206}
207
208/* recurse down mux tree */
209static int i2cdev_check_mux_children(struct device *dev, void *addrp)
210{
211 int result;
212
213 if (dev->type == &i2c_adapter_type)
214 result = device_for_each_child(dev, addrp,
215 i2cdev_check_mux_children);
216 else
217 result = i2cdev_check(dev, addrp);
218
219 return result;
220}
221
Jean Delvarebd4217d2007-11-15 19:24:01 +0100222/* This address checking function differs from the one in i2c-core
223 in that it considers an address with a registered device, but no
David Brownell9b766b82008-01-27 18:14:51 +0100224 driver bound to it, as NOT busy. */
Jean Delvarebd4217d2007-11-15 19:24:01 +0100225static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
226{
Jean Delvare97cc4d42010-10-24 18:16:57 +0200227 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
Michael Lawnick08263742010-08-11 18:21:02 +0200228 int result = 0;
229
Jean Delvare97cc4d42010-10-24 18:16:57 +0200230 if (parent)
231 result = i2cdev_check_mux_parents(parent, addr);
Michael Lawnick08263742010-08-11 18:21:02 +0200232
233 if (!result)
234 result = device_for_each_child(&adapter->dev, &addr,
235 i2cdev_check_mux_children);
236
237 return result;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100238}
239
Jean Delvarec57d3e72015-09-08 11:05:49 +0200240static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client,
Jean Delvaredba79972008-04-22 22:16:47 +0200241 unsigned long arg)
242{
243 struct i2c_rdwr_ioctl_data rdwr_arg;
244 struct i2c_msg *rdwr_pa;
245 u8 __user **data_ptrs;
246 int i, res;
247
248 if (copy_from_user(&rdwr_arg,
249 (struct i2c_rdwr_ioctl_data __user *)arg,
250 sizeof(rdwr_arg)))
251 return -EFAULT;
252
253 /* Put an arbitrary limit on the number of messages that can
254 * be sent at once */
Jean Delvarec57d3e72015-09-08 11:05:49 +0200255 if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS)
Jean Delvaredba79972008-04-22 22:16:47 +0200256 return -EINVAL;
257
Thomas Meyera699ed6f2012-01-12 20:32:04 +0100258 rdwr_pa = memdup_user(rdwr_arg.msgs,
259 rdwr_arg.nmsgs * sizeof(struct i2c_msg));
260 if (IS_ERR(rdwr_pa))
261 return PTR_ERR(rdwr_pa);
Jean Delvaredba79972008-04-22 22:16:47 +0200262
263 data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
264 if (data_ptrs == NULL) {
265 kfree(rdwr_pa);
266 return -ENOMEM;
267 }
268
269 res = 0;
270 for (i = 0; i < rdwr_arg.nmsgs; i++) {
Jean Delvare838bfa62012-05-30 10:55:34 +0200271 /* Limit the size of the message to a sane amount */
272 if (rdwr_pa[i].len > 8192) {
Jean Delvaredba79972008-04-22 22:16:47 +0200273 res = -EINVAL;
274 break;
275 }
Jean Delvare838bfa62012-05-30 10:55:34 +0200276
Jean Delvaredba79972008-04-22 22:16:47 +0200277 data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
Julia Lawallf1c2e332010-08-11 18:20:55 +0200278 rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len);
279 if (IS_ERR(rdwr_pa[i].buf)) {
280 res = PTR_ERR(rdwr_pa[i].buf);
Jean Delvaredba79972008-04-22 22:16:47 +0200281 break;
282 }
Jean Delvare838bfa62012-05-30 10:55:34 +0200283
284 /*
285 * If the message length is received from the slave (similar
286 * to SMBus block read), we must ensure that the buffer will
287 * be large enough to cope with a message length of
288 * I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus
289 * drivers allow. The first byte in the buffer must be
290 * pre-filled with the number of extra bytes, which must be
291 * at least one to hold the message length, but can be
292 * greater (for example to account for a checksum byte at
293 * the end of the message.)
294 */
295 if (rdwr_pa[i].flags & I2C_M_RECV_LEN) {
296 if (!(rdwr_pa[i].flags & I2C_M_RD) ||
297 rdwr_pa[i].buf[0] < 1 ||
298 rdwr_pa[i].len < rdwr_pa[i].buf[0] +
299 I2C_SMBUS_BLOCK_MAX) {
300 res = -EINVAL;
301 break;
302 }
303
304 rdwr_pa[i].len = rdwr_pa[i].buf[0];
305 }
Jean Delvaredba79972008-04-22 22:16:47 +0200306 }
307 if (res < 0) {
308 int j;
309 for (j = 0; j < i; ++j)
310 kfree(rdwr_pa[j].buf);
311 kfree(data_ptrs);
312 kfree(rdwr_pa);
313 return res;
314 }
315
316 res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs);
317 while (i-- > 0) {
318 if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) {
319 if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf,
320 rdwr_pa[i].len))
321 res = -EFAULT;
322 }
323 kfree(rdwr_pa[i].buf);
324 }
325 kfree(data_ptrs);
326 kfree(rdwr_pa);
327 return res;
328}
329
330static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
331 unsigned long arg)
332{
333 struct i2c_smbus_ioctl_data data_arg;
334 union i2c_smbus_data temp;
335 int datasize, res;
336
337 if (copy_from_user(&data_arg,
338 (struct i2c_smbus_ioctl_data __user *) arg,
339 sizeof(struct i2c_smbus_ioctl_data)))
340 return -EFAULT;
341 if ((data_arg.size != I2C_SMBUS_BYTE) &&
342 (data_arg.size != I2C_SMBUS_QUICK) &&
343 (data_arg.size != I2C_SMBUS_BYTE_DATA) &&
344 (data_arg.size != I2C_SMBUS_WORD_DATA) &&
345 (data_arg.size != I2C_SMBUS_PROC_CALL) &&
346 (data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
347 (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
348 (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
349 (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
350 dev_dbg(&client->adapter->dev,
351 "size out of range (%x) in ioctl I2C_SMBUS.\n",
352 data_arg.size);
353 return -EINVAL;
354 }
355 /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
356 so the check is valid if size==I2C_SMBUS_QUICK too. */
357 if ((data_arg.read_write != I2C_SMBUS_READ) &&
358 (data_arg.read_write != I2C_SMBUS_WRITE)) {
359 dev_dbg(&client->adapter->dev,
360 "read_write out of range (%x) in ioctl I2C_SMBUS.\n",
361 data_arg.read_write);
362 return -EINVAL;
363 }
364
365 /* Note that command values are always valid! */
366
367 if ((data_arg.size == I2C_SMBUS_QUICK) ||
368 ((data_arg.size == I2C_SMBUS_BYTE) &&
369 (data_arg.read_write == I2C_SMBUS_WRITE)))
370 /* These are special: we do not use data */
371 return i2c_smbus_xfer(client->adapter, client->addr,
372 client->flags, data_arg.read_write,
373 data_arg.command, data_arg.size, NULL);
374
375 if (data_arg.data == NULL) {
376 dev_dbg(&client->adapter->dev,
377 "data is NULL pointer in ioctl I2C_SMBUS.\n");
378 return -EINVAL;
379 }
380
381 if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
382 (data_arg.size == I2C_SMBUS_BYTE))
383 datasize = sizeof(data_arg.data->byte);
384 else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
385 (data_arg.size == I2C_SMBUS_PROC_CALL))
386 datasize = sizeof(data_arg.data->word);
387 else /* size == smbus block, i2c block, or block proc. call */
388 datasize = sizeof(data_arg.data->block);
389
390 if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
391 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
392 (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
393 (data_arg.read_write == I2C_SMBUS_WRITE)) {
394 if (copy_from_user(&temp, data_arg.data, datasize))
395 return -EFAULT;
396 }
397 if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
398 /* Convert old I2C block commands to the new
399 convention. This preserves binary compatibility. */
400 data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
401 if (data_arg.read_write == I2C_SMBUS_READ)
402 temp.block[0] = I2C_SMBUS_BLOCK_MAX;
403 }
404 res = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
405 data_arg.read_write, data_arg.command, data_arg.size, &temp);
406 if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
407 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
408 (data_arg.read_write == I2C_SMBUS_READ))) {
409 if (copy_to_user(data_arg.data, &temp, datasize))
410 return -EFAULT;
411 }
412 return res;
413}
414
Alan Cox77e38bf2008-07-14 22:38:27 +0200415static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416{
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200417 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 unsigned long funcs;
419
Jean Delvaree8aafcb2005-10-07 23:06:27 +0200420 dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
421 cmd, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422
Farid Hammaneae5624f2010-05-21 18:40:59 +0200423 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 case I2C_SLAVE:
425 case I2C_SLAVE_FORCE:
David Brownell438d6c22006-12-10 21:21:31 +0100426 if ((arg > 0x3ff) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
428 return -EINVAL;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100429 if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 return -EBUSY;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100431 /* REVISIT: address could become busy later */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 client->addr = arg;
433 return 0;
434 case I2C_TENBIT:
435 if (arg)
436 client->flags |= I2C_M_TEN;
437 else
438 client->flags &= ~I2C_M_TEN;
439 return 0;
440 case I2C_PEC:
Jean Delvare9e685c82015-09-11 11:27:18 +0200441 /*
442 * Setting the PEC flag here won't affect kernel drivers,
443 * which will be using the i2c_client node registered with
444 * the driver model core. Likewise, when that client has
445 * the PEC flag already set, the i2c-dev driver won't see
446 * (or use) this setting.
447 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 if (arg)
449 client->flags |= I2C_CLIENT_PEC;
450 else
451 client->flags &= ~I2C_CLIENT_PEC;
452 return 0;
453 case I2C_FUNCS:
454 funcs = i2c_get_functionality(client->adapter);
Jean Delvare2c003e82006-12-10 21:21:30 +0100455 return put_user(funcs, (unsigned long __user *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
457 case I2C_RDWR:
Jean Delvarec57d3e72015-09-08 11:05:49 +0200458 return i2cdev_ioctl_rdwr(client, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459
460 case I2C_SMBUS:
Jean Delvaredba79972008-04-22 22:16:47 +0200461 return i2cdev_ioctl_smbus(client, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462
David Brownell53be7952007-10-13 23:56:32 +0200463 case I2C_RETRIES:
464 client->adapter->retries = arg;
465 break;
466 case I2C_TIMEOUT:
Jean Delvarecd97f392009-02-24 19:19:49 +0100467 /* For historical reasons, user-space sets the timeout
468 * value in units of 10 ms.
469 */
470 client->adapter->timeout = msecs_to_jiffies(arg * 10);
David Brownell53be7952007-10-13 23:56:32 +0200471 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 default:
David Brownell53be7952007-10-13 23:56:32 +0200473 /* NOTE: returning a fault code here could cause trouble
474 * in buggy userspace code. Some old kernel bugs returned
475 * zero in this case, and userspace code might accidentally
476 * have depended on that bug.
477 */
478 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 }
480 return 0;
481}
482
483static int i2cdev_open(struct inode *inode, struct file *file)
484{
485 unsigned int minor = iminor(inode);
486 struct i2c_client *client;
487 struct i2c_adapter *adap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488
viresh kumar5136ed42016-07-05 19:57:06 -0700489 adap = i2c_get_adapter(minor);
Vincent Sanders9669f542009-12-06 17:06:26 +0100490 if (!adap)
491 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492
David Brownell907135a2007-11-15 19:24:01 +0100493 /* This creates an anonymous i2c_client, which may later be
494 * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE.
495 *
496 * This client is ** NEVER REGISTERED ** with the driver model
497 * or I2C core code!! It just holds private copies of addressing
498 * information and maybe a PEC flag.
499 */
Jean Delvare22f76e72006-07-01 17:20:57 +0200500 client = kzalloc(sizeof(*client), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 if (!client) {
502 i2c_put_adapter(adap);
Vincent Sanders9669f542009-12-06 17:06:26 +0100503 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 }
Jean Delvare22f76e72006-07-01 17:20:57 +0200505 snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 client->adapter = adap;
508 file->private_data = client;
509
Vincent Sanders9669f542009-12-06 17:06:26 +0100510 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511}
512
513static int i2cdev_release(struct inode *inode, struct file *file)
514{
515 struct i2c_client *client = file->private_data;
516
517 i2c_put_adapter(client->adapter);
518 kfree(client);
519 file->private_data = NULL;
520
521 return 0;
522}
523
Arjan van de Ven2b8693c2007-02-12 00:55:32 -0800524static const struct file_operations i2cdev_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 .owner = THIS_MODULE,
526 .llseek = no_llseek,
527 .read = i2cdev_read,
528 .write = i2cdev_write,
Alan Cox77e38bf2008-07-14 22:38:27 +0200529 .unlocked_ioctl = i2cdev_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 .open = i2cdev_open,
531 .release = i2cdev_release,
532};
533
David Brownell907135a2007-11-15 19:24:01 +0100534/* ------------------------------------------------------------------------- */
535
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800536static struct class *i2c_dev_class;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537
Jean Delvare9ea3e942011-03-20 14:50:52 +0100538static int i2cdev_attach_adapter(struct device *dev, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100540 struct i2c_adapter *adap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 struct i2c_dev *i2c_dev;
Jean Delvaredefcb462006-08-15 18:30:24 +0200542 int res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543
Jean Delvare9ea3e942011-03-20 14:50:52 +0100544 if (dev->type != &i2c_adapter_type)
545 return 0;
546 adap = to_i2c_adapter(dev);
547
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 i2c_dev = get_free_i2c_dev(adap);
549 if (IS_ERR(i2c_dev))
550 return PTR_ERR(i2c_dev);
551
Erico Nunesd6760b12016-05-03 15:45:43 -0300552 cdev_init(&i2c_dev->cdev, &i2cdev_fops);
553 i2c_dev->cdev.owner = THIS_MODULE;
554 res = cdev_add(&i2c_dev->cdev, MKDEV(I2C_MAJOR, adap->nr), 1);
555 if (res)
556 goto error_cdev;
557
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 /* register this i2c device with the driver core */
Greg Kroah-Hartmana9b12612008-07-21 20:03:34 -0700559 i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
560 MKDEV(I2C_MAJOR, adap->nr), NULL,
561 "i2c-%d", adap->nr);
Akinobu Mita3bacb362006-12-10 21:21:33 +0100562 if (IS_ERR(i2c_dev->dev)) {
563 res = PTR_ERR(i2c_dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 goto error;
Jean Delvaredefcb462006-08-15 18:30:24 +0200565 }
Jean Delvareb32d20d2006-09-03 22:19:25 +0200566
567 pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
568 adap->name, adap->nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 return 0;
570error:
Erico Nunesd6760b12016-05-03 15:45:43 -0300571 cdev_del(&i2c_dev->cdev);
572error_cdev:
Wolfram Sang72a71f82016-05-27 13:13:01 +0200573 put_i2c_dev(i2c_dev);
Jean Delvaredefcb462006-08-15 18:30:24 +0200574 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575}
576
Jean Delvare9ea3e942011-03-20 14:50:52 +0100577static int i2cdev_detach_adapter(struct device *dev, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100579 struct i2c_adapter *adap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 struct i2c_dev *i2c_dev;
581
Jean Delvare9ea3e942011-03-20 14:50:52 +0100582 if (dev->type != &i2c_adapter_type)
583 return 0;
584 adap = to_i2c_adapter(dev);
585
Jean Delvare9455e4c2006-07-01 17:16:57 +0200586 i2c_dev = i2c_dev_get_by_minor(adap->nr);
Jean Delvareb32d20d2006-09-03 22:19:25 +0200587 if (!i2c_dev) /* attach_adapter must have failed */
588 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589
Dan Carpentere6be18f2016-05-28 08:01:46 +0300590 cdev_del(&i2c_dev->cdev);
Wolfram Sang72a71f82016-05-27 13:13:01 +0200591 put_i2c_dev(i2c_dev);
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700592 device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593
Jean Delvareb6d7b3d2005-07-31 19:02:53 +0200594 pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 return 0;
596}
597
Shubhrajyoti Deff245c2011-11-23 11:33:07 +0100598static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action,
Jean Delvare9ea3e942011-03-20 14:50:52 +0100599 void *data)
600{
601 struct device *dev = data;
602
603 switch (action) {
604 case BUS_NOTIFY_ADD_DEVICE:
605 return i2cdev_attach_adapter(dev, NULL);
606 case BUS_NOTIFY_DEL_DEVICE:
607 return i2cdev_detach_adapter(dev, NULL);
608 }
609
610 return 0;
611}
612
613static struct notifier_block i2cdev_notifier = {
614 .notifier_call = i2cdev_notifier_call,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615};
616
David Brownell907135a2007-11-15 19:24:01 +0100617/* ------------------------------------------------------------------------- */
618
619/*
620 * module load/unload record keeping
621 */
622
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623static int __init i2c_dev_init(void)
624{
625 int res;
626
627 printk(KERN_INFO "i2c /dev entries driver\n");
628
Erico Nunesd6760b12016-05-03 15:45:43 -0300629 res = register_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS, "i2c");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 if (res)
631 goto out;
632
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800633 i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
Sven Wegenere74783e2008-09-24 13:39:21 +0200634 if (IS_ERR(i2c_dev_class)) {
635 res = PTR_ERR(i2c_dev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 goto out_unreg_chrdev;
Sven Wegenere74783e2008-09-24 13:39:21 +0200637 }
Guenter Roeck45f176a2013-09-26 19:36:11 -0700638 i2c_dev_class->dev_groups = i2c_groups;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639
Jean Delvare9ea3e942011-03-20 14:50:52 +0100640 /* Keep track of adapters which will be added or removed later */
641 res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 if (res)
643 goto out_unreg_class;
644
Jean Delvare9ea3e942011-03-20 14:50:52 +0100645 /* Bind to already existing adapters right away */
646 i2c_for_each_dev(NULL, i2cdev_attach_adapter);
647
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 return 0;
649
650out_unreg_class:
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800651 class_destroy(i2c_dev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652out_unreg_chrdev:
Erico Nunesd6760b12016-05-03 15:45:43 -0300653 unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654out:
655 printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
656 return res;
657}
658
659static void __exit i2c_dev_exit(void)
660{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100661 bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier);
662 i2c_for_each_dev(NULL, i2cdev_detach_adapter);
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800663 class_destroy(i2c_dev_class);
Erico Nunesd6760b12016-05-03 15:45:43 -0300664 unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665}
666
667MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
668 "Simon G. Vogl <simon@tk.uni-linz.ac.at>");
669MODULE_DESCRIPTION("I2C /dev entries driver");
670MODULE_LICENSE("GPL");
671
672module_init(i2c_dev_init);
673module_exit(i2c_dev_exit);