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Thomas Gleixnerc942fdd2019-05-27 08:55:06 +02001// SPDX-License-Identifier: GPL-2.0-or-later
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
David Brownell438d6c22006-12-10 21:21:31 +01003 i2c-dev.c - i2c-bus driver, char device interface
Linus Torvalds1da177e2005-04-16 15:20:36 -07004
5 Copyright (C) 1995-97 Simon G. Vogl
6 Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
7 Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
8
Linus Torvalds1da177e2005-04-16 15:20:36 -07009*/
10
11/* Note that this is a complete rewrite of Simon Vogl's i2c-dev module.
12 But I have used so much of his original code and ideas that it seems
13 only fair to recognize him as co-author -- Frodo */
14
15/* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */
16
Erico Nunesd6760b12016-05-03 15:45:43 -030017#include <linux/cdev.h>
Jean Delvare9ea3e942011-03-20 14:50:52 +010018#include <linux/device.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/i2c-dev.h>
Wolfram Sanga8766072016-02-20 23:33:38 +010021#include <linux/i2c.h>
22#include <linux/init.h>
Jean Delvarecd97f392009-02-24 19:19:49 +010023#include <linux/jiffies.h>
Wolfram Sanga8766072016-02-20 23:33:38 +010024#include <linux/kernel.h>
25#include <linux/list.h>
26#include <linux/module.h>
27#include <linux/notifier.h>
28#include <linux/slab.h>
Farid Hammaneae5624f2010-05-21 18:40:59 +020029#include <linux/uaccess.h>
Al Viro7d5cb452017-09-20 01:02:27 -040030#include <linux/compat.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
David Brownell907135a2007-11-15 19:24:01 +010032/*
33 * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a
34 * slave (i2c_client) with which messages will be exchanged. It's coupled
35 * with a character special file which is accessed by user mode drivers.
36 *
37 * The list of i2c_dev structures is parallel to the i2c_adapter lists
Jean Delvare9ea3e942011-03-20 14:50:52 +010038 * maintained by the driver model, and is updated using bus notifications.
David Brownell907135a2007-11-15 19:24:01 +010039 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070040struct i2c_dev {
Jean Delvaref3b3aad2006-07-01 17:17:38 +020041 struct list_head list;
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 struct i2c_adapter *adap;
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -070043 struct device *dev;
Erico Nunesd6760b12016-05-03 15:45:43 -030044 struct cdev cdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070045};
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
Chengguang Xu8a6d5082019-02-12 14:06:57 +080047#define I2C_MINORS (MINORMASK + 1)
Jean Delvaref3b3aad2006-07-01 17:17:38 +020048static LIST_HEAD(i2c_dev_list);
49static DEFINE_SPINLOCK(i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
51static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
52{
53 struct i2c_dev *i2c_dev;
54
Jean Delvaref3b3aad2006-07-01 17:17:38 +020055 spin_lock(&i2c_dev_list_lock);
56 list_for_each_entry(i2c_dev, &i2c_dev_list, list) {
57 if (i2c_dev->adap->nr == index)
58 goto found;
59 }
60 i2c_dev = NULL;
61found:
62 spin_unlock(&i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 return i2c_dev;
64}
65
Linus Torvalds1da177e2005-04-16 15:20:36 -070066static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
67{
68 struct i2c_dev *i2c_dev;
69
Jean Delvaref3b3aad2006-07-01 17:17:38 +020070 if (adap->nr >= I2C_MINORS) {
71 printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
72 adap->nr);
73 return ERR_PTR(-ENODEV);
74 }
75
Deepak Saxena5263ebb2005-10-17 23:09:43 +020076 i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 if (!i2c_dev)
78 return ERR_PTR(-ENOMEM);
Jean Delvare9455e4c2006-07-01 17:16:57 +020079 i2c_dev->adap = adap;
Jean Delvaref3b3aad2006-07-01 17:17:38 +020080
81 spin_lock(&i2c_dev_list_lock);
82 list_add_tail(&i2c_dev->list, &i2c_dev_list);
83 spin_unlock(&i2c_dev_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 return i2c_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070085}
86
Wolfram Sang72a71f82016-05-27 13:13:01 +020087static void put_i2c_dev(struct i2c_dev *i2c_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070088{
Jean Delvaref3b3aad2006-07-01 17:17:38 +020089 spin_lock(&i2c_dev_list_lock);
90 list_del(&i2c_dev->list);
91 spin_unlock(&i2c_dev_list_lock);
Jean Delvare07125ab2006-12-10 21:21:33 +010092 kfree(i2c_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093}
94
Guenter Roeck45f176a2013-09-26 19:36:11 -070095static ssize_t name_show(struct device *dev,
96 struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070097{
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -070098 struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt));
Greg Kroah-Hartman794721322005-12-06 15:33:15 -080099
100 if (!i2c_dev)
101 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 return sprintf(buf, "%s\n", i2c_dev->adap->name);
103}
Guenter Roeck45f176a2013-09-26 19:36:11 -0700104static DEVICE_ATTR_RO(name);
105
106static struct attribute *i2c_attrs[] = {
107 &dev_attr_name.attr,
108 NULL,
109};
110ATTRIBUTE_GROUPS(i2c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111
David Brownell907135a2007-11-15 19:24:01 +0100112/* ------------------------------------------------------------------------- */
113
114/*
115 * After opening an instance of this character special file, a file
116 * descriptor starts out associated only with an i2c_adapter (and bus).
117 *
118 * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg
119 * traffic to any devices on the bus used by that adapter. That's because
120 * the i2c_msg vectors embed all the addressing information they need, and
121 * are submitted directly to an i2c_adapter. However, SMBus-only adapters
122 * don't support that interface.
123 *
124 * To use read()/write() system calls on that file descriptor, or to use
125 * SMBus interfaces (and work with SMBus-only hosts!), you must first issue
126 * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous
127 * (never registered) i2c_client so it holds the addressing information
128 * needed by those system calls and by this SMBus interface.
129 */
130
Farid Hammaneae5624f2010-05-21 18:40:59 +0200131static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count,
132 loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133{
134 char *tmp;
135 int ret;
136
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200137 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138
139 if (count > 8192)
140 count = 8192;
141
Farid Hammaneae5624f2010-05-21 18:40:59 +0200142 tmp = kmalloc(count, GFP_KERNEL);
143 if (tmp == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 return -ENOMEM;
145
David Brownell2ce5b342008-08-10 22:56:16 +0200146 pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n",
Al Viro496ad9a2013-01-23 17:07:38 -0500147 iminor(file_inode(file)), count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148
Farid Hammaneae5624f2010-05-21 18:40:59 +0200149 ret = i2c_master_recv(client, tmp, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 if (ret >= 0)
Farid Hammaneae5624f2010-05-21 18:40:59 +0200151 ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 kfree(tmp);
153 return ret;
154}
155
Farid Hammaneae5624f2010-05-21 18:40:59 +0200156static ssize_t i2cdev_write(struct file *file, const char __user *buf,
157 size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158{
159 int ret;
160 char *tmp;
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200161 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
163 if (count > 8192)
164 count = 8192;
165
Julia Lawallf1c2e332010-08-11 18:20:55 +0200166 tmp = memdup_user(buf, count);
167 if (IS_ERR(tmp))
168 return PTR_ERR(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
David Brownell2ce5b342008-08-10 22:56:16 +0200170 pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n",
Al Viro496ad9a2013-01-23 17:07:38 -0500171 iminor(file_inode(file)), count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172
Farid Hammaneae5624f2010-05-21 18:40:59 +0200173 ret = i2c_master_send(client, tmp, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 kfree(tmp);
175 return ret;
176}
177
David Brownell9b766b82008-01-27 18:14:51 +0100178static int i2cdev_check(struct device *dev, void *addrp)
179{
180 struct i2c_client *client = i2c_verify_client(dev);
181
182 if (!client || client->addr != *(unsigned int *)addrp)
183 return 0;
184
185 return dev->driver ? -EBUSY : 0;
186}
187
Michael Lawnick08263742010-08-11 18:21:02 +0200188/* walk up mux tree */
189static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
190{
Jean Delvare97cc4d42010-10-24 18:16:57 +0200191 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
Michael Lawnick08263742010-08-11 18:21:02 +0200192 int result;
193
194 result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
Jean Delvare97cc4d42010-10-24 18:16:57 +0200195 if (!result && parent)
196 result = i2cdev_check_mux_parents(parent, addr);
Michael Lawnick08263742010-08-11 18:21:02 +0200197
198 return result;
199}
200
201/* recurse down mux tree */
202static int i2cdev_check_mux_children(struct device *dev, void *addrp)
203{
204 int result;
205
206 if (dev->type == &i2c_adapter_type)
207 result = device_for_each_child(dev, addrp,
208 i2cdev_check_mux_children);
209 else
210 result = i2cdev_check(dev, addrp);
211
212 return result;
213}
214
Jean Delvarebd4217d2007-11-15 19:24:01 +0100215/* This address checking function differs from the one in i2c-core
216 in that it considers an address with a registered device, but no
David Brownell9b766b82008-01-27 18:14:51 +0100217 driver bound to it, as NOT busy. */
Jean Delvarebd4217d2007-11-15 19:24:01 +0100218static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
219{
Jean Delvare97cc4d42010-10-24 18:16:57 +0200220 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
Michael Lawnick08263742010-08-11 18:21:02 +0200221 int result = 0;
222
Jean Delvare97cc4d42010-10-24 18:16:57 +0200223 if (parent)
224 result = i2cdev_check_mux_parents(parent, addr);
Michael Lawnick08263742010-08-11 18:21:02 +0200225
226 if (!result)
227 result = device_for_each_child(&adapter->dev, &addr,
228 i2cdev_check_mux_children);
229
230 return result;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100231}
232
Jean Delvarec57d3e72015-09-08 11:05:49 +0200233static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client,
Al Viro7d5cb452017-09-20 01:02:27 -0400234 unsigned nmsgs, struct i2c_msg *msgs)
Jean Delvaredba79972008-04-22 22:16:47 +0200235{
Jean Delvaredba79972008-04-22 22:16:47 +0200236 u8 __user **data_ptrs;
237 int i, res;
238
Kees Cook6da2ec52018-06-12 13:55:00 -0700239 data_ptrs = kmalloc_array(nmsgs, sizeof(u8 __user *), GFP_KERNEL);
Jean Delvaredba79972008-04-22 22:16:47 +0200240 if (data_ptrs == NULL) {
Al Viro7d5cb452017-09-20 01:02:27 -0400241 kfree(msgs);
Jean Delvaredba79972008-04-22 22:16:47 +0200242 return -ENOMEM;
243 }
244
245 res = 0;
Al Viro7d5cb452017-09-20 01:02:27 -0400246 for (i = 0; i < nmsgs; i++) {
Jean Delvare838bfa62012-05-30 10:55:34 +0200247 /* Limit the size of the message to a sane amount */
Al Viro7d5cb452017-09-20 01:02:27 -0400248 if (msgs[i].len > 8192) {
Jean Delvaredba79972008-04-22 22:16:47 +0200249 res = -EINVAL;
250 break;
251 }
Jean Delvare838bfa62012-05-30 10:55:34 +0200252
Al Viro7d5cb452017-09-20 01:02:27 -0400253 data_ptrs[i] = (u8 __user *)msgs[i].buf;
254 msgs[i].buf = memdup_user(data_ptrs[i], msgs[i].len);
255 if (IS_ERR(msgs[i].buf)) {
256 res = PTR_ERR(msgs[i].buf);
Jean Delvaredba79972008-04-22 22:16:47 +0200257 break;
258 }
Wolfram Sang978336d2017-11-04 21:20:03 +0100259 /* memdup_user allocates with GFP_KERNEL, so DMA is ok */
260 msgs[i].flags |= I2C_M_DMA_SAFE;
Jean Delvare838bfa62012-05-30 10:55:34 +0200261
262 /*
263 * If the message length is received from the slave (similar
264 * to SMBus block read), we must ensure that the buffer will
265 * be large enough to cope with a message length of
266 * I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus
267 * drivers allow. The first byte in the buffer must be
268 * pre-filled with the number of extra bytes, which must be
269 * at least one to hold the message length, but can be
270 * greater (for example to account for a checksum byte at
271 * the end of the message.)
272 */
Al Viro7d5cb452017-09-20 01:02:27 -0400273 if (msgs[i].flags & I2C_M_RECV_LEN) {
274 if (!(msgs[i].flags & I2C_M_RD) ||
Alexander Popov23a27722018-04-19 15:29:22 +0300275 msgs[i].len < 1 || msgs[i].buf[0] < 1 ||
Al Viro7d5cb452017-09-20 01:02:27 -0400276 msgs[i].len < msgs[i].buf[0] +
Jean Delvare838bfa62012-05-30 10:55:34 +0200277 I2C_SMBUS_BLOCK_MAX) {
278 res = -EINVAL;
279 break;
280 }
281
Al Viro7d5cb452017-09-20 01:02:27 -0400282 msgs[i].len = msgs[i].buf[0];
Jean Delvare838bfa62012-05-30 10:55:34 +0200283 }
Jean Delvaredba79972008-04-22 22:16:47 +0200284 }
285 if (res < 0) {
286 int j;
287 for (j = 0; j < i; ++j)
Al Viro7d5cb452017-09-20 01:02:27 -0400288 kfree(msgs[j].buf);
Jean Delvaredba79972008-04-22 22:16:47 +0200289 kfree(data_ptrs);
Al Viro7d5cb452017-09-20 01:02:27 -0400290 kfree(msgs);
Jean Delvaredba79972008-04-22 22:16:47 +0200291 return res;
292 }
293
Al Viro7d5cb452017-09-20 01:02:27 -0400294 res = i2c_transfer(client->adapter, msgs, nmsgs);
Jean Delvaredba79972008-04-22 22:16:47 +0200295 while (i-- > 0) {
Al Viro7d5cb452017-09-20 01:02:27 -0400296 if (res >= 0 && (msgs[i].flags & I2C_M_RD)) {
297 if (copy_to_user(data_ptrs[i], msgs[i].buf,
298 msgs[i].len))
Jean Delvaredba79972008-04-22 22:16:47 +0200299 res = -EFAULT;
300 }
Al Viro7d5cb452017-09-20 01:02:27 -0400301 kfree(msgs[i].buf);
Jean Delvaredba79972008-04-22 22:16:47 +0200302 }
303 kfree(data_ptrs);
Al Viro7d5cb452017-09-20 01:02:27 -0400304 kfree(msgs);
Jean Delvaredba79972008-04-22 22:16:47 +0200305 return res;
306}
307
308static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
Al Viro7d5cb452017-09-20 01:02:27 -0400309 u8 read_write, u8 command, u32 size,
310 union i2c_smbus_data __user *data)
Jean Delvaredba79972008-04-22 22:16:47 +0200311{
Vlad Tsyrklevich30f939f2017-01-09 22:53:36 +0700312 union i2c_smbus_data temp = {};
Jean Delvaredba79972008-04-22 22:16:47 +0200313 int datasize, res;
314
Al Viro7d5cb452017-09-20 01:02:27 -0400315 if ((size != I2C_SMBUS_BYTE) &&
316 (size != I2C_SMBUS_QUICK) &&
317 (size != I2C_SMBUS_BYTE_DATA) &&
318 (size != I2C_SMBUS_WORD_DATA) &&
319 (size != I2C_SMBUS_PROC_CALL) &&
320 (size != I2C_SMBUS_BLOCK_DATA) &&
321 (size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
322 (size != I2C_SMBUS_I2C_BLOCK_DATA) &&
323 (size != I2C_SMBUS_BLOCK_PROC_CALL)) {
Jean Delvaredba79972008-04-22 22:16:47 +0200324 dev_dbg(&client->adapter->dev,
325 "size out of range (%x) in ioctl I2C_SMBUS.\n",
Al Viro7d5cb452017-09-20 01:02:27 -0400326 size);
Jean Delvaredba79972008-04-22 22:16:47 +0200327 return -EINVAL;
328 }
329 /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
330 so the check is valid if size==I2C_SMBUS_QUICK too. */
Al Viro7d5cb452017-09-20 01:02:27 -0400331 if ((read_write != I2C_SMBUS_READ) &&
332 (read_write != I2C_SMBUS_WRITE)) {
Jean Delvaredba79972008-04-22 22:16:47 +0200333 dev_dbg(&client->adapter->dev,
334 "read_write out of range (%x) in ioctl I2C_SMBUS.\n",
Al Viro7d5cb452017-09-20 01:02:27 -0400335 read_write);
Jean Delvaredba79972008-04-22 22:16:47 +0200336 return -EINVAL;
337 }
338
339 /* Note that command values are always valid! */
340
Al Viro7d5cb452017-09-20 01:02:27 -0400341 if ((size == I2C_SMBUS_QUICK) ||
342 ((size == I2C_SMBUS_BYTE) &&
343 (read_write == I2C_SMBUS_WRITE)))
Jean Delvaredba79972008-04-22 22:16:47 +0200344 /* These are special: we do not use data */
345 return i2c_smbus_xfer(client->adapter, client->addr,
Al Viro7d5cb452017-09-20 01:02:27 -0400346 client->flags, read_write,
347 command, size, NULL);
Jean Delvaredba79972008-04-22 22:16:47 +0200348
Al Viro7d5cb452017-09-20 01:02:27 -0400349 if (data == NULL) {
Jean Delvaredba79972008-04-22 22:16:47 +0200350 dev_dbg(&client->adapter->dev,
351 "data is NULL pointer in ioctl I2C_SMBUS.\n");
352 return -EINVAL;
353 }
354
Al Viro7d5cb452017-09-20 01:02:27 -0400355 if ((size == I2C_SMBUS_BYTE_DATA) ||
356 (size == I2C_SMBUS_BYTE))
357 datasize = sizeof(data->byte);
358 else if ((size == I2C_SMBUS_WORD_DATA) ||
359 (size == I2C_SMBUS_PROC_CALL))
360 datasize = sizeof(data->word);
Jean Delvaredba79972008-04-22 22:16:47 +0200361 else /* size == smbus block, i2c block, or block proc. call */
Al Viro7d5cb452017-09-20 01:02:27 -0400362 datasize = sizeof(data->block);
Jean Delvaredba79972008-04-22 22:16:47 +0200363
Al Viro7d5cb452017-09-20 01:02:27 -0400364 if ((size == I2C_SMBUS_PROC_CALL) ||
365 (size == I2C_SMBUS_BLOCK_PROC_CALL) ||
366 (size == I2C_SMBUS_I2C_BLOCK_DATA) ||
367 (read_write == I2C_SMBUS_WRITE)) {
368 if (copy_from_user(&temp, data, datasize))
Jean Delvaredba79972008-04-22 22:16:47 +0200369 return -EFAULT;
370 }
Al Viro7d5cb452017-09-20 01:02:27 -0400371 if (size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
Jean Delvaredba79972008-04-22 22:16:47 +0200372 /* Convert old I2C block commands to the new
373 convention. This preserves binary compatibility. */
Al Viro7d5cb452017-09-20 01:02:27 -0400374 size = I2C_SMBUS_I2C_BLOCK_DATA;
375 if (read_write == I2C_SMBUS_READ)
Jean Delvaredba79972008-04-22 22:16:47 +0200376 temp.block[0] = I2C_SMBUS_BLOCK_MAX;
377 }
378 res = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
Al Viro7d5cb452017-09-20 01:02:27 -0400379 read_write, command, size, &temp);
380 if (!res && ((size == I2C_SMBUS_PROC_CALL) ||
381 (size == I2C_SMBUS_BLOCK_PROC_CALL) ||
382 (read_write == I2C_SMBUS_READ))) {
383 if (copy_to_user(data, &temp, datasize))
Jean Delvaredba79972008-04-22 22:16:47 +0200384 return -EFAULT;
385 }
386 return res;
387}
388
Alan Cox77e38bf2008-07-14 22:38:27 +0200389static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390{
H Hartley Sweeten0be16c32010-05-21 18:40:57 +0200391 struct i2c_client *client = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 unsigned long funcs;
393
Jean Delvaree8aafcb2005-10-07 23:06:27 +0200394 dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
395 cmd, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396
Farid Hammaneae5624f2010-05-21 18:40:59 +0200397 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 case I2C_SLAVE:
399 case I2C_SLAVE_FORCE:
David Brownell438d6c22006-12-10 21:21:31 +0100400 if ((arg > 0x3ff) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
402 return -EINVAL;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100403 if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 return -EBUSY;
Jean Delvarebd4217d2007-11-15 19:24:01 +0100405 /* REVISIT: address could become busy later */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 client->addr = arg;
407 return 0;
408 case I2C_TENBIT:
409 if (arg)
410 client->flags |= I2C_M_TEN;
411 else
412 client->flags &= ~I2C_M_TEN;
413 return 0;
414 case I2C_PEC:
Jean Delvare9e685c82015-09-11 11:27:18 +0200415 /*
416 * Setting the PEC flag here won't affect kernel drivers,
417 * which will be using the i2c_client node registered with
418 * the driver model core. Likewise, when that client has
419 * the PEC flag already set, the i2c-dev driver won't see
420 * (or use) this setting.
421 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 if (arg)
423 client->flags |= I2C_CLIENT_PEC;
424 else
425 client->flags &= ~I2C_CLIENT_PEC;
426 return 0;
427 case I2C_FUNCS:
428 funcs = i2c_get_functionality(client->adapter);
Jean Delvare2c003e82006-12-10 21:21:30 +0100429 return put_user(funcs, (unsigned long __user *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430
Al Viro7d5cb452017-09-20 01:02:27 -0400431 case I2C_RDWR: {
432 struct i2c_rdwr_ioctl_data rdwr_arg;
433 struct i2c_msg *rdwr_pa;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434
Al Viro7d5cb452017-09-20 01:02:27 -0400435 if (copy_from_user(&rdwr_arg,
436 (struct i2c_rdwr_ioctl_data __user *)arg,
437 sizeof(rdwr_arg)))
438 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439
Al Viro7d5cb452017-09-20 01:02:27 -0400440 /* Put an arbitrary limit on the number of messages that can
441 * be sent at once */
442 if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS)
443 return -EINVAL;
444
445 rdwr_pa = memdup_user(rdwr_arg.msgs,
446 rdwr_arg.nmsgs * sizeof(struct i2c_msg));
447 if (IS_ERR(rdwr_pa))
448 return PTR_ERR(rdwr_pa);
449
450 return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa);
451 }
452
453 case I2C_SMBUS: {
454 struct i2c_smbus_ioctl_data data_arg;
455 if (copy_from_user(&data_arg,
456 (struct i2c_smbus_ioctl_data __user *) arg,
457 sizeof(struct i2c_smbus_ioctl_data)))
458 return -EFAULT;
459 return i2cdev_ioctl_smbus(client, data_arg.read_write,
460 data_arg.command,
461 data_arg.size,
462 data_arg.data);
463 }
David Brownell53be7952007-10-13 23:56:32 +0200464 case I2C_RETRIES:
Yi Zeng6ebec9612019-01-09 15:33:07 +0800465 if (arg > INT_MAX)
466 return -EINVAL;
467
David Brownell53be7952007-10-13 23:56:32 +0200468 client->adapter->retries = arg;
469 break;
470 case I2C_TIMEOUT:
Yi Zeng6ebec9612019-01-09 15:33:07 +0800471 if (arg > INT_MAX)
472 return -EINVAL;
473
Jean Delvarecd97f392009-02-24 19:19:49 +0100474 /* For historical reasons, user-space sets the timeout
475 * value in units of 10 ms.
476 */
477 client->adapter->timeout = msecs_to_jiffies(arg * 10);
David Brownell53be7952007-10-13 23:56:32 +0200478 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 default:
David Brownell53be7952007-10-13 23:56:32 +0200480 /* NOTE: returning a fault code here could cause trouble
481 * in buggy userspace code. Some old kernel bugs returned
482 * zero in this case, and userspace code might accidentally
483 * have depended on that bug.
484 */
485 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 }
487 return 0;
488}
489
Al Viro7d5cb452017-09-20 01:02:27 -0400490#ifdef CONFIG_COMPAT
491
492struct i2c_smbus_ioctl_data32 {
493 u8 read_write;
494 u8 command;
495 u32 size;
496 compat_caddr_t data; /* union i2c_smbus_data *data */
497};
498
499struct i2c_msg32 {
500 u16 addr;
501 u16 flags;
502 u16 len;
503 compat_caddr_t buf;
504};
505
506struct i2c_rdwr_ioctl_data32 {
507 compat_caddr_t msgs; /* struct i2c_msg __user *msgs */
508 u32 nmsgs;
509};
510
511static long compat_i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
512{
513 struct i2c_client *client = file->private_data;
514 unsigned long funcs;
515 switch (cmd) {
516 case I2C_FUNCS:
517 funcs = i2c_get_functionality(client->adapter);
518 return put_user(funcs, (compat_ulong_t __user *)arg);
519 case I2C_RDWR: {
520 struct i2c_rdwr_ioctl_data32 rdwr_arg;
521 struct i2c_msg32 *p;
522 struct i2c_msg *rdwr_pa;
523 int i;
524
525 if (copy_from_user(&rdwr_arg,
526 (struct i2c_rdwr_ioctl_data32 __user *)arg,
527 sizeof(rdwr_arg)))
528 return -EFAULT;
529
530 if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS)
531 return -EINVAL;
532
533 rdwr_pa = kmalloc_array(rdwr_arg.nmsgs, sizeof(struct i2c_msg),
534 GFP_KERNEL);
535 if (!rdwr_pa)
536 return -ENOMEM;
537
538 p = compat_ptr(rdwr_arg.msgs);
539 for (i = 0; i < rdwr_arg.nmsgs; i++) {
540 struct i2c_msg32 umsg;
541 if (copy_from_user(&umsg, p + i, sizeof(umsg))) {
542 kfree(rdwr_pa);
543 return -EFAULT;
544 }
545 rdwr_pa[i] = (struct i2c_msg) {
546 .addr = umsg.addr,
547 .flags = umsg.flags,
548 .len = umsg.len,
549 .buf = compat_ptr(umsg.buf)
550 };
551 }
552
553 return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa);
554 }
555 case I2C_SMBUS: {
556 struct i2c_smbus_ioctl_data32 data32;
557 if (copy_from_user(&data32,
558 (void __user *) arg,
559 sizeof(data32)))
560 return -EFAULT;
561 return i2cdev_ioctl_smbus(client, data32.read_write,
562 data32.command,
563 data32.size,
564 compat_ptr(data32.data));
565 }
566 default:
567 return i2cdev_ioctl(file, cmd, arg);
568 }
569}
570#else
571#define compat_i2cdev_ioctl NULL
572#endif
573
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574static int i2cdev_open(struct inode *inode, struct file *file)
575{
576 unsigned int minor = iminor(inode);
577 struct i2c_client *client;
578 struct i2c_adapter *adap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579
viresh kumar5136ed42016-07-05 19:57:06 -0700580 adap = i2c_get_adapter(minor);
Vincent Sanders9669f542009-12-06 17:06:26 +0100581 if (!adap)
582 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583
David Brownell907135a2007-11-15 19:24:01 +0100584 /* This creates an anonymous i2c_client, which may later be
585 * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE.
586 *
587 * This client is ** NEVER REGISTERED ** with the driver model
588 * or I2C core code!! It just holds private copies of addressing
589 * information and maybe a PEC flag.
590 */
Jean Delvare22f76e72006-07-01 17:20:57 +0200591 client = kzalloc(sizeof(*client), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 if (!client) {
593 i2c_put_adapter(adap);
Vincent Sanders9669f542009-12-06 17:06:26 +0100594 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 }
Jean Delvare22f76e72006-07-01 17:20:57 +0200596 snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 client->adapter = adap;
599 file->private_data = client;
600
Vincent Sanders9669f542009-12-06 17:06:26 +0100601 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602}
603
604static int i2cdev_release(struct inode *inode, struct file *file)
605{
606 struct i2c_client *client = file->private_data;
607
608 i2c_put_adapter(client->adapter);
609 kfree(client);
610 file->private_data = NULL;
611
612 return 0;
613}
614
Arjan van de Ven2b8693c2007-02-12 00:55:32 -0800615static const struct file_operations i2cdev_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 .owner = THIS_MODULE,
617 .llseek = no_llseek,
618 .read = i2cdev_read,
619 .write = i2cdev_write,
Alan Cox77e38bf2008-07-14 22:38:27 +0200620 .unlocked_ioctl = i2cdev_ioctl,
Al Viro7d5cb452017-09-20 01:02:27 -0400621 .compat_ioctl = compat_i2cdev_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 .open = i2cdev_open,
623 .release = i2cdev_release,
624};
625
David Brownell907135a2007-11-15 19:24:01 +0100626/* ------------------------------------------------------------------------- */
627
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800628static struct class *i2c_dev_class;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
Jean Delvare9ea3e942011-03-20 14:50:52 +0100630static int i2cdev_attach_adapter(struct device *dev, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100632 struct i2c_adapter *adap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 struct i2c_dev *i2c_dev;
Jean Delvaredefcb462006-08-15 18:30:24 +0200634 int res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635
Jean Delvare9ea3e942011-03-20 14:50:52 +0100636 if (dev->type != &i2c_adapter_type)
637 return 0;
638 adap = to_i2c_adapter(dev);
639
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 i2c_dev = get_free_i2c_dev(adap);
641 if (IS_ERR(i2c_dev))
642 return PTR_ERR(i2c_dev);
643
Erico Nunesd6760b12016-05-03 15:45:43 -0300644 cdev_init(&i2c_dev->cdev, &i2cdev_fops);
645 i2c_dev->cdev.owner = THIS_MODULE;
646 res = cdev_add(&i2c_dev->cdev, MKDEV(I2C_MAJOR, adap->nr), 1);
647 if (res)
648 goto error_cdev;
649
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 /* register this i2c device with the driver core */
Greg Kroah-Hartmana9b12612008-07-21 20:03:34 -0700651 i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
652 MKDEV(I2C_MAJOR, adap->nr), NULL,
653 "i2c-%d", adap->nr);
Akinobu Mita3bacb362006-12-10 21:21:33 +0100654 if (IS_ERR(i2c_dev->dev)) {
655 res = PTR_ERR(i2c_dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 goto error;
Jean Delvaredefcb462006-08-15 18:30:24 +0200657 }
Jean Delvareb32d20d2006-09-03 22:19:25 +0200658
659 pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
660 adap->name, adap->nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 return 0;
662error:
Erico Nunesd6760b12016-05-03 15:45:43 -0300663 cdev_del(&i2c_dev->cdev);
664error_cdev:
Wolfram Sang72a71f82016-05-27 13:13:01 +0200665 put_i2c_dev(i2c_dev);
Jean Delvaredefcb462006-08-15 18:30:24 +0200666 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667}
668
Jean Delvare9ea3e942011-03-20 14:50:52 +0100669static int i2cdev_detach_adapter(struct device *dev, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100671 struct i2c_adapter *adap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 struct i2c_dev *i2c_dev;
673
Jean Delvare9ea3e942011-03-20 14:50:52 +0100674 if (dev->type != &i2c_adapter_type)
675 return 0;
676 adap = to_i2c_adapter(dev);
677
Jean Delvare9455e4c2006-07-01 17:16:57 +0200678 i2c_dev = i2c_dev_get_by_minor(adap->nr);
Jean Delvareb32d20d2006-09-03 22:19:25 +0200679 if (!i2c_dev) /* attach_adapter must have failed */
680 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681
Dan Carpentere6be18f2016-05-28 08:01:46 +0300682 cdev_del(&i2c_dev->cdev);
Wolfram Sang72a71f82016-05-27 13:13:01 +0200683 put_i2c_dev(i2c_dev);
Greg Kroah-Hartmanac11d062006-07-03 13:46:24 -0700684 device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685
Jean Delvareb6d7b3d2005-07-31 19:02:53 +0200686 pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 return 0;
688}
689
Shubhrajyoti Deff245c2011-11-23 11:33:07 +0100690static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action,
Jean Delvare9ea3e942011-03-20 14:50:52 +0100691 void *data)
692{
693 struct device *dev = data;
694
695 switch (action) {
696 case BUS_NOTIFY_ADD_DEVICE:
697 return i2cdev_attach_adapter(dev, NULL);
698 case BUS_NOTIFY_DEL_DEVICE:
699 return i2cdev_detach_adapter(dev, NULL);
700 }
701
702 return 0;
703}
704
705static struct notifier_block i2cdev_notifier = {
706 .notifier_call = i2cdev_notifier_call,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707};
708
David Brownell907135a2007-11-15 19:24:01 +0100709/* ------------------------------------------------------------------------- */
710
711/*
712 * module load/unload record keeping
713 */
714
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715static int __init i2c_dev_init(void)
716{
717 int res;
718
719 printk(KERN_INFO "i2c /dev entries driver\n");
720
Erico Nunesd6760b12016-05-03 15:45:43 -0300721 res = register_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS, "i2c");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 if (res)
723 goto out;
724
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800725 i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
Sven Wegenere74783e2008-09-24 13:39:21 +0200726 if (IS_ERR(i2c_dev_class)) {
727 res = PTR_ERR(i2c_dev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 goto out_unreg_chrdev;
Sven Wegenere74783e2008-09-24 13:39:21 +0200729 }
Guenter Roeck45f176a2013-09-26 19:36:11 -0700730 i2c_dev_class->dev_groups = i2c_groups;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731
Jean Delvare9ea3e942011-03-20 14:50:52 +0100732 /* Keep track of adapters which will be added or removed later */
733 res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 if (res)
735 goto out_unreg_class;
736
Jean Delvare9ea3e942011-03-20 14:50:52 +0100737 /* Bind to already existing adapters right away */
738 i2c_for_each_dev(NULL, i2cdev_attach_adapter);
739
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 return 0;
741
742out_unreg_class:
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800743 class_destroy(i2c_dev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744out_unreg_chrdev:
Erico Nunesd6760b12016-05-03 15:45:43 -0300745 unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746out:
747 printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
748 return res;
749}
750
751static void __exit i2c_dev_exit(void)
752{
Jean Delvare9ea3e942011-03-20 14:50:52 +0100753 bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier);
754 i2c_for_each_dev(NULL, i2cdev_detach_adapter);
Greg Kroah-Hartman794721322005-12-06 15:33:15 -0800755 class_destroy(i2c_dev_class);
Erico Nunesd6760b12016-05-03 15:45:43 -0300756 unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757}
758
759MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
760 "Simon G. Vogl <simon@tk.uni-linz.ac.at>");
761MODULE_DESCRIPTION("I2C /dev entries driver");
762MODULE_LICENSE("GPL");
763
764module_init(i2c_dev_init);
765module_exit(i2c_dev_exit);