Contributors: 44
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Linus Torvalds (pre-git) |
965 |
28.82% |
29 |
23.97% |
| Jean Delvare |
683 |
20.40% |
20 |
16.53% |
| Al Viro |
468 |
13.98% |
4 |
3.31% |
| Greg Kroah-Hartman |
396 |
11.83% |
12 |
9.92% |
| Michael Lawnick |
115 |
3.43% |
1 |
0.83% |
| Kevin Hao |
91 |
2.72% |
1 |
0.83% |
| David Brownell |
83 |
2.48% |
4 |
3.31% |
| Erico Nunes |
65 |
1.94% |
1 |
0.83% |
| Andrew Morton |
56 |
1.67% |
2 |
1.65% |
| Wolfram Sang |
55 |
1.64% |
4 |
3.31% |
| Albert Cranford |
43 |
1.28% |
3 |
2.48% |
| Andy Shevchenko |
40 |
1.19% |
4 |
3.31% |
| Gerd Knorr |
38 |
1.14% |
1 |
0.83% |
| Christoph Hellwig |
36 |
1.08% |
3 |
2.48% |
| Luiz Fernando N. Capitulino |
34 |
1.02% |
1 |
0.83% |
| Guenter Roeck |
28 |
0.84% |
1 |
0.83% |
| Dave Jones |
20 |
0.60% |
1 |
0.83% |
| Yi Zeng |
20 |
0.60% |
1 |
0.83% |
| Julia Lawall |
16 |
0.48% |
1 |
0.83% |
| Art Haas |
13 |
0.39% |
1 |
0.83% |
| Pavel Machek |
10 |
0.30% |
1 |
0.83% |
| Alexander Popov |
9 |
0.27% |
1 |
0.83% |
| Sven Wegener |
9 |
0.27% |
1 |
0.83% |
| Linus Torvalds |
6 |
0.18% |
2 |
1.65% |
| Thomas Gleixner |
6 |
0.18% |
2 |
1.65% |
| Adrian Bunk |
6 |
0.18% |
1 |
0.83% |
| Akinobu Mita |
5 |
0.15% |
1 |
0.83% |
| Vincent Sanders |
5 |
0.15% |
1 |
0.83% |
| Zhiwu Song |
4 |
0.12% |
1 |
0.83% |
| Yingjoe Chen |
3 |
0.09% |
1 |
0.83% |
| Alan Cox |
2 |
0.06% |
1 |
0.83% |
| Pavel Skripkin |
2 |
0.06% |
1 |
0.83% |
| Vlad Tsyrklevich |
2 |
0.06% |
1 |
0.83% |
| Kees Cook |
2 |
0.06% |
1 |
0.83% |
| Mark M. Hoffman |
2 |
0.06% |
1 |
0.83% |
| Kay Sievers |
2 |
0.06% |
1 |
0.83% |
| Arjan van de Ven |
1 |
0.03% |
1 |
0.83% |
| Farid Hammane |
1 |
0.03% |
1 |
0.83% |
| Viresh Kumar |
1 |
0.03% |
1 |
0.83% |
| Shubhrajyoti Datta |
1 |
0.03% |
1 |
0.83% |
| Chengguang Xu |
1 |
0.03% |
1 |
0.83% |
| Deepak Saxena |
1 |
0.03% |
1 |
0.83% |
| Andreas Hecht |
1 |
0.03% |
1 |
0.83% |
| Jarkko Nikula |
1 |
0.03% |
1 |
0.83% |
| Total |
3348 |
|
121 |
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
i2c-dev.c - i2c-bus driver, char device interface
Copyright (C) 1995-97 Simon G. Vogl
Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
*/
/* Note that this is a complete rewrite of Simon Vogl's i2c-dev module.
But I have used so much of his original code and ideas that it seems
only fair to recognize him as co-author -- Frodo */
/* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/cdev.h>
#include <linux/compat.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/i2c-dev.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
/*
* An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a
* slave (i2c_client) with which messages will be exchanged. It's coupled
* with a character special file which is accessed by user mode drivers.
*
* The list of i2c_dev structures is parallel to the i2c_adapter lists
* maintained by the driver model, and is updated using bus notifications.
*/
struct i2c_dev {
struct list_head list;
struct i2c_adapter *adap;
struct device dev;
struct cdev cdev;
};
#define I2C_MINORS (MINORMASK + 1)
static LIST_HEAD(i2c_dev_list);
static DEFINE_SPINLOCK(i2c_dev_list_lock);
static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
{
struct i2c_dev *i2c_dev;
spin_lock(&i2c_dev_list_lock);
list_for_each_entry(i2c_dev, &i2c_dev_list, list) {
if (i2c_dev->adap->nr == index)
goto found;
}
i2c_dev = NULL;
found:
spin_unlock(&i2c_dev_list_lock);
return i2c_dev;
}
static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
{
struct i2c_dev *i2c_dev;
if (adap->nr >= I2C_MINORS) {
pr_err("Out of device minors (%d)\n", adap->nr);
return ERR_PTR(-ENODEV);
}
i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
if (!i2c_dev)
return ERR_PTR(-ENOMEM);
i2c_dev->adap = adap;
spin_lock(&i2c_dev_list_lock);
list_add_tail(&i2c_dev->list, &i2c_dev_list);
spin_unlock(&i2c_dev_list_lock);
return i2c_dev;
}
static void put_i2c_dev(struct i2c_dev *i2c_dev, bool del_cdev)
{
spin_lock(&i2c_dev_list_lock);
list_del(&i2c_dev->list);
spin_unlock(&i2c_dev_list_lock);
if (del_cdev)
cdev_device_del(&i2c_dev->cdev, &i2c_dev->dev);
put_device(&i2c_dev->dev);
}
static ssize_t name_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt));
if (!i2c_dev)
return -ENODEV;
return sysfs_emit(buf, "%s\n", i2c_dev->adap->name);
}
static DEVICE_ATTR_RO(name);
static struct attribute *i2c_attrs[] = {
&dev_attr_name.attr,
NULL,
};
ATTRIBUTE_GROUPS(i2c);
/* ------------------------------------------------------------------------- */
/*
* After opening an instance of this character special file, a file
* descriptor starts out associated only with an i2c_adapter (and bus).
*
* Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg
* traffic to any devices on the bus used by that adapter. That's because
* the i2c_msg vectors embed all the addressing information they need, and
* are submitted directly to an i2c_adapter. However, SMBus-only adapters
* don't support that interface.
*
* To use read()/write() system calls on that file descriptor, or to use
* SMBus interfaces (and work with SMBus-only hosts!), you must first issue
* an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous
* (never registered) i2c_client so it holds the addressing information
* needed by those system calls and by this SMBus interface.
*/
static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count,
loff_t *offset)
{
char *tmp;
int ret;
struct i2c_client *client = file->private_data;
if (count > 8192)
count = 8192;
tmp = kzalloc(count, GFP_KERNEL);
if (tmp == NULL)
return -ENOMEM;
pr_debug("i2c-%d reading %zu bytes.\n", iminor(file_inode(file)), count);
ret = i2c_master_recv(client, tmp, count);
if (ret >= 0)
if (copy_to_user(buf, tmp, ret))
ret = -EFAULT;
kfree(tmp);
return ret;
}
static ssize_t i2cdev_write(struct file *file, const char __user *buf,
size_t count, loff_t *offset)
{
int ret;
char *tmp;
struct i2c_client *client = file->private_data;
if (count > 8192)
count = 8192;
tmp = memdup_user(buf, count);
if (IS_ERR(tmp))
return PTR_ERR(tmp);
pr_debug("i2c-%d writing %zu bytes.\n", iminor(file_inode(file)), count);
ret = i2c_master_send(client, tmp, count);
kfree(tmp);
return ret;
}
static int i2cdev_check(struct device *dev, void *addrp)
{
struct i2c_client *client = i2c_verify_client(dev);
if (!client || client->addr != *(unsigned int *)addrp)
return 0;
return dev->driver ? -EBUSY : 0;
}
/* walk up mux tree */
static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
{
struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
int result;
result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
if (!result && parent)
result = i2cdev_check_mux_parents(parent, addr);
return result;
}
/* recurse down mux tree */
static int i2cdev_check_mux_children(struct device *dev, void *addrp)
{
int result;
if (dev->type == &i2c_adapter_type)
result = device_for_each_child(dev, addrp,
i2cdev_check_mux_children);
else
result = i2cdev_check(dev, addrp);
return result;
}
/* This address checking function differs from the one in i2c-core
in that it considers an address with a registered device, but no
driver bound to it, as NOT busy. */
static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
{
struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
int result = 0;
if (parent)
result = i2cdev_check_mux_parents(parent, addr);
if (!result)
result = device_for_each_child(&adapter->dev, &addr,
i2cdev_check_mux_children);
return result;
}
static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client,
unsigned nmsgs, struct i2c_msg *msgs)
{
u8 __user **data_ptrs;
int i, res;
data_ptrs = kmalloc_array(nmsgs, sizeof(u8 __user *), GFP_KERNEL);
if (data_ptrs == NULL) {
kfree(msgs);
return -ENOMEM;
}
res = 0;
for (i = 0; i < nmsgs; i++) {
/* Limit the size of the message to a sane amount */
if (msgs[i].len > 8192) {
res = -EINVAL;
break;
}
data_ptrs[i] = (u8 __user *)msgs[i].buf;
msgs[i].buf = memdup_user(data_ptrs[i], msgs[i].len);
if (IS_ERR(msgs[i].buf)) {
res = PTR_ERR(msgs[i].buf);
break;
}
/* memdup_user allocates with GFP_KERNEL, so DMA is ok */
msgs[i].flags |= I2C_M_DMA_SAFE;
/*
* If the message length is received from the slave (similar
* to SMBus block read), we must ensure that the buffer will
* be large enough to cope with a message length of
* I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus
* drivers allow. The first byte in the buffer must be
* pre-filled with the number of extra bytes, which must be
* at least one to hold the message length, but can be
* greater (for example to account for a checksum byte at
* the end of the message.)
*/
if (msgs[i].flags & I2C_M_RECV_LEN) {
if (!(msgs[i].flags & I2C_M_RD) ||
msgs[i].len < 1 || msgs[i].buf[0] < 1 ||
msgs[i].len < msgs[i].buf[0] +
I2C_SMBUS_BLOCK_MAX) {
i++;
res = -EINVAL;
break;
}
msgs[i].len = msgs[i].buf[0];
}
}
if (res < 0) {
int j;
for (j = 0; j < i; ++j)
kfree(msgs[j].buf);
kfree(data_ptrs);
kfree(msgs);
return res;
}
res = i2c_transfer(client->adapter, msgs, nmsgs);
while (i-- > 0) {
if (res >= 0 && (msgs[i].flags & I2C_M_RD)) {
if (copy_to_user(data_ptrs[i], msgs[i].buf,
msgs[i].len))
res = -EFAULT;
}
kfree(msgs[i].buf);
}
kfree(data_ptrs);
kfree(msgs);
return res;
}
static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
u8 read_write, u8 command, u32 size,
union i2c_smbus_data __user *data)
{
union i2c_smbus_data temp = {};
int datasize, res;
if ((size != I2C_SMBUS_BYTE) &&
(size != I2C_SMBUS_QUICK) &&
(size != I2C_SMBUS_BYTE_DATA) &&
(size != I2C_SMBUS_WORD_DATA) &&
(size != I2C_SMBUS_PROC_CALL) &&
(size != I2C_SMBUS_BLOCK_DATA) &&
(size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
(size != I2C_SMBUS_I2C_BLOCK_DATA) &&
(size != I2C_SMBUS_BLOCK_PROC_CALL)) {
dev_dbg(&client->adapter->dev,
"size out of range (%x) in ioctl I2C_SMBUS.\n",
size);
return -EINVAL;
}
/* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
so the check is valid if size==I2C_SMBUS_QUICK too. */
if ((read_write != I2C_SMBUS_READ) &&
(read_write != I2C_SMBUS_WRITE)) {
dev_dbg(&client->adapter->dev,
"read_write out of range (%x) in ioctl I2C_SMBUS.\n",
read_write);
return -EINVAL;
}
/* Note that command values are always valid! */
if ((size == I2C_SMBUS_QUICK) ||
((size == I2C_SMBUS_BYTE) &&
(read_write == I2C_SMBUS_WRITE)))
/* These are special: we do not use data */
return i2c_smbus_xfer(client->adapter, client->addr,
client->flags, read_write,
command, size, NULL);
if (data == NULL) {
dev_dbg(&client->adapter->dev,
"data is NULL pointer in ioctl I2C_SMBUS.\n");
return -EINVAL;
}
if ((size == I2C_SMBUS_BYTE_DATA) ||
(size == I2C_SMBUS_BYTE))
datasize = sizeof(data->byte);
else if ((size == I2C_SMBUS_WORD_DATA) ||
(size == I2C_SMBUS_PROC_CALL))
datasize = sizeof(data->word);
else /* size == smbus block, i2c block, or block proc. call */
datasize = sizeof(data->block);
if ((size == I2C_SMBUS_PROC_CALL) ||
(size == I2C_SMBUS_BLOCK_PROC_CALL) ||
(size == I2C_SMBUS_I2C_BLOCK_DATA) ||
(read_write == I2C_SMBUS_WRITE)) {
if (copy_from_user(&temp, data, datasize))
return -EFAULT;
}
if (size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
/* Convert old I2C block commands to the new
convention. This preserves binary compatibility. */
size = I2C_SMBUS_I2C_BLOCK_DATA;
if (read_write == I2C_SMBUS_READ)
temp.block[0] = I2C_SMBUS_BLOCK_MAX;
}
res = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
read_write, command, size, &temp);
if (!res && ((size == I2C_SMBUS_PROC_CALL) ||
(size == I2C_SMBUS_BLOCK_PROC_CALL) ||
(read_write == I2C_SMBUS_READ))) {
if (copy_to_user(data, &temp, datasize))
return -EFAULT;
}
return res;
}
static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct i2c_client *client = file->private_data;
unsigned long funcs;
dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
cmd, arg);
switch (cmd) {
case I2C_SLAVE:
case I2C_SLAVE_FORCE:
if ((arg > 0x3ff) ||
(((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
return -EINVAL;
if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg))
return -EBUSY;
/* REVISIT: address could become busy later */
client->addr = arg;
return 0;
case I2C_TENBIT:
if (arg)
client->flags |= I2C_M_TEN;
else
client->flags &= ~I2C_M_TEN;
return 0;
case I2C_PEC:
/*
* Setting the PEC flag here won't affect kernel drivers,
* which will be using the i2c_client node registered with
* the driver model core. Likewise, when that client has
* the PEC flag already set, the i2c-dev driver won't see
* (or use) this setting.
*/
if (arg)
client->flags |= I2C_CLIENT_PEC;
else
client->flags &= ~I2C_CLIENT_PEC;
return 0;
case I2C_FUNCS:
funcs = i2c_get_functionality(client->adapter);
return put_user(funcs, (unsigned long __user *)arg);
case I2C_RDWR: {
struct i2c_rdwr_ioctl_data rdwr_arg;
struct i2c_msg *rdwr_pa;
if (copy_from_user(&rdwr_arg,
(struct i2c_rdwr_ioctl_data __user *)arg,
sizeof(rdwr_arg)))
return -EFAULT;
if (!rdwr_arg.msgs || rdwr_arg.nmsgs == 0)
return -EINVAL;
/*
* Put an arbitrary limit on the number of messages that can
* be sent at once
*/
if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS)
return -EINVAL;
rdwr_pa = memdup_user(rdwr_arg.msgs,
rdwr_arg.nmsgs * sizeof(struct i2c_msg));
if (IS_ERR(rdwr_pa))
return PTR_ERR(rdwr_pa);
return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa);
}
case I2C_SMBUS: {
struct i2c_smbus_ioctl_data data_arg;
if (copy_from_user(&data_arg,
(struct i2c_smbus_ioctl_data __user *) arg,
sizeof(struct i2c_smbus_ioctl_data)))
return -EFAULT;
return i2cdev_ioctl_smbus(client, data_arg.read_write,
data_arg.command,
data_arg.size,
data_arg.data);
}
case I2C_RETRIES:
if (arg > INT_MAX)
return -EINVAL;
client->adapter->retries = arg;
break;
case I2C_TIMEOUT:
if (arg > INT_MAX)
return -EINVAL;
/* For historical reasons, user-space sets the timeout
* value in units of 10 ms.
*/
client->adapter->timeout = msecs_to_jiffies(arg * 10);
break;
default:
/* NOTE: returning a fault code here could cause trouble
* in buggy userspace code. Some old kernel bugs returned
* zero in this case, and userspace code might accidentally
* have depended on that bug.
*/
return -ENOTTY;
}
return 0;
}
#ifdef CONFIG_COMPAT
struct i2c_smbus_ioctl_data32 {
u8 read_write;
u8 command;
u32 size;
compat_caddr_t data; /* union i2c_smbus_data *data */
};
struct i2c_msg32 {
u16 addr;
u16 flags;
u16 len;
compat_caddr_t buf;
};
struct i2c_rdwr_ioctl_data32 {
compat_caddr_t msgs; /* struct i2c_msg __user *msgs */
u32 nmsgs;
};
static long compat_i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct i2c_client *client = file->private_data;
unsigned long funcs;
switch (cmd) {
case I2C_FUNCS:
funcs = i2c_get_functionality(client->adapter);
return put_user(funcs, (compat_ulong_t __user *)arg);
case I2C_RDWR: {
struct i2c_rdwr_ioctl_data32 rdwr_arg;
struct i2c_msg32 __user *p;
struct i2c_msg *rdwr_pa;
int i;
if (copy_from_user(&rdwr_arg,
(struct i2c_rdwr_ioctl_data32 __user *)arg,
sizeof(rdwr_arg)))
return -EFAULT;
if (!rdwr_arg.msgs || rdwr_arg.nmsgs == 0)
return -EINVAL;
if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS)
return -EINVAL;
rdwr_pa = kmalloc_array(rdwr_arg.nmsgs, sizeof(struct i2c_msg),
GFP_KERNEL);
if (!rdwr_pa)
return -ENOMEM;
p = compat_ptr(rdwr_arg.msgs);
for (i = 0; i < rdwr_arg.nmsgs; i++) {
struct i2c_msg32 umsg;
if (copy_from_user(&umsg, p + i, sizeof(umsg))) {
kfree(rdwr_pa);
return -EFAULT;
}
rdwr_pa[i] = (struct i2c_msg) {
.addr = umsg.addr,
.flags = umsg.flags,
.len = umsg.len,
.buf = (__force __u8 *)compat_ptr(umsg.buf),
};
}
return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa);
}
case I2C_SMBUS: {
struct i2c_smbus_ioctl_data32 data32;
if (copy_from_user(&data32,
(void __user *) arg,
sizeof(data32)))
return -EFAULT;
return i2cdev_ioctl_smbus(client, data32.read_write,
data32.command,
data32.size,
compat_ptr(data32.data));
}
default:
return i2cdev_ioctl(file, cmd, arg);
}
}
#else
#define compat_i2cdev_ioctl NULL
#endif
static int i2cdev_open(struct inode *inode, struct file *file)
{
unsigned int minor = iminor(inode);
struct i2c_client *client;
struct i2c_adapter *adap;
adap = i2c_get_adapter(minor);
if (!adap)
return -ENODEV;
/* This creates an anonymous i2c_client, which may later be
* pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE.
*
* This client is ** NEVER REGISTERED ** with the driver model
* or I2C core code!! It just holds private copies of addressing
* information and maybe a PEC flag.
*/
client = kzalloc(sizeof(*client), GFP_KERNEL);
if (!client) {
i2c_put_adapter(adap);
return -ENOMEM;
}
snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
client->adapter = adap;
file->private_data = client;
return 0;
}
static int i2cdev_release(struct inode *inode, struct file *file)
{
struct i2c_client *client = file->private_data;
i2c_put_adapter(client->adapter);
kfree(client);
file->private_data = NULL;
return 0;
}
static const struct file_operations i2cdev_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = i2cdev_read,
.write = i2cdev_write,
.unlocked_ioctl = i2cdev_ioctl,
.compat_ioctl = compat_i2cdev_ioctl,
.open = i2cdev_open,
.release = i2cdev_release,
};
/* ------------------------------------------------------------------------- */
static struct class *i2c_dev_class;
static void i2cdev_dev_release(struct device *dev)
{
struct i2c_dev *i2c_dev;
i2c_dev = container_of(dev, struct i2c_dev, dev);
kfree(i2c_dev);
}
static int i2cdev_attach_adapter(struct device *dev, void *dummy)
{
struct i2c_adapter *adap;
struct i2c_dev *i2c_dev;
int res;
if (dev->type != &i2c_adapter_type)
return 0;
adap = to_i2c_adapter(dev);
i2c_dev = get_free_i2c_dev(adap);
if (IS_ERR(i2c_dev))
return PTR_ERR(i2c_dev);
cdev_init(&i2c_dev->cdev, &i2cdev_fops);
i2c_dev->cdev.owner = THIS_MODULE;
device_initialize(&i2c_dev->dev);
i2c_dev->dev.devt = MKDEV(I2C_MAJOR, adap->nr);
i2c_dev->dev.class = i2c_dev_class;
i2c_dev->dev.parent = &adap->dev;
i2c_dev->dev.release = i2cdev_dev_release;
res = dev_set_name(&i2c_dev->dev, "i2c-%d", adap->nr);
if (res)
goto err_put_i2c_dev;
res = cdev_device_add(&i2c_dev->cdev, &i2c_dev->dev);
if (res)
goto err_put_i2c_dev;
pr_debug("adapter [%s] registered as minor %d\n", adap->name, adap->nr);
return 0;
err_put_i2c_dev:
put_i2c_dev(i2c_dev, false);
return res;
}
static int i2cdev_detach_adapter(struct device *dev, void *dummy)
{
struct i2c_adapter *adap;
struct i2c_dev *i2c_dev;
if (dev->type != &i2c_adapter_type)
return 0;
adap = to_i2c_adapter(dev);
i2c_dev = i2c_dev_get_by_minor(adap->nr);
if (!i2c_dev) /* attach_adapter must have failed */
return 0;
put_i2c_dev(i2c_dev, true);
pr_debug("adapter [%s] unregistered\n", adap->name);
return 0;
}
static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action,
void *data)
{
struct device *dev = data;
switch (action) {
case BUS_NOTIFY_ADD_DEVICE:
return i2cdev_attach_adapter(dev, NULL);
case BUS_NOTIFY_DEL_DEVICE:
return i2cdev_detach_adapter(dev, NULL);
}
return 0;
}
static struct notifier_block i2cdev_notifier = {
.notifier_call = i2cdev_notifier_call,
};
/* ------------------------------------------------------------------------- */
/*
* module load/unload record keeping
*/
static int __init i2c_dev_init(void)
{
int res;
pr_info("i2c /dev entries driver\n");
res = register_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS, "i2c");
if (res)
goto out;
i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
if (IS_ERR(i2c_dev_class)) {
res = PTR_ERR(i2c_dev_class);
goto out_unreg_chrdev;
}
i2c_dev_class->dev_groups = i2c_groups;
/* Keep track of adapters which will be added or removed later */
res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
if (res)
goto out_unreg_class;
/* Bind to already existing adapters right away */
i2c_for_each_dev(NULL, i2cdev_attach_adapter);
return 0;
out_unreg_class:
class_destroy(i2c_dev_class);
out_unreg_chrdev:
unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS);
out:
pr_err("Driver Initialisation failed\n");
return res;
}
static void __exit i2c_dev_exit(void)
{
bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier);
i2c_for_each_dev(NULL, i2cdev_detach_adapter);
class_destroy(i2c_dev_class);
unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS);
}
MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
MODULE_DESCRIPTION("I2C /dev entries driver");
MODULE_LICENSE("GPL");
module_init(i2c_dev_init);
module_exit(i2c_dev_exit);