mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![Jean Delvare](/assets/img/avatar_default.png)
As the bus driver side implementation of I2C_M_RECV_LEN is heavily tied to SMBus, we can't support received length over 32 bytes, but let's at least support that. In practice, the caller will have to setup a buffer large enough to cover the case where received length byte has value 32, so minimum 32 + 1 = 33 bytes, possibly more if there is a fixed number of bytes added for the specific slave (for example a checksum.) Signed-off-by: Jean Delvare <khali@linux-fr.org> Tested-by: Douglas Gilbert <dgilbert@interlog.com>
674 lines
18 KiB
C
674 lines
18 KiB
C
/*
|
|
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>
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
|
|
MA 02110-1301 USA.
|
|
*/
|
|
|
|
/* 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> */
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/device.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/init.h>
|
|
#include <linux/list.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/i2c-dev.h>
|
|
#include <linux/jiffies.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;
|
|
};
|
|
|
|
#define I2C_MINORS 256
|
|
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) {
|
|
printk(KERN_ERR "i2c-dev: 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 return_i2c_dev(struct i2c_dev *i2c_dev)
|
|
{
|
|
spin_lock(&i2c_dev_list_lock);
|
|
list_del(&i2c_dev->list);
|
|
spin_unlock(&i2c_dev_list_lock);
|
|
kfree(i2c_dev);
|
|
}
|
|
|
|
static ssize_t show_adapter_name(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 sprintf(buf, "%s\n", i2c_dev->adap->name);
|
|
}
|
|
static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
|
|
|
|
/* ------------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* 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 = kmalloc(count, GFP_KERNEL);
|
|
if (tmp == NULL)
|
|
return -ENOMEM;
|
|
|
|
pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n",
|
|
iminor(file->f_path.dentry->d_inode), count);
|
|
|
|
ret = i2c_master_recv(client, tmp, count);
|
|
if (ret >= 0)
|
|
ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret;
|
|
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-dev: i2c-%d writing %zu bytes.\n",
|
|
iminor(file->f_path.dentry->d_inode), 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_rdrw(struct i2c_client *client,
|
|
unsigned long arg)
|
|
{
|
|
struct i2c_rdwr_ioctl_data rdwr_arg;
|
|
struct i2c_msg *rdwr_pa;
|
|
u8 __user **data_ptrs;
|
|
int i, res;
|
|
|
|
if (copy_from_user(&rdwr_arg,
|
|
(struct i2c_rdwr_ioctl_data __user *)arg,
|
|
sizeof(rdwr_arg)))
|
|
return -EFAULT;
|
|
|
|
/* Put an arbitrary limit on the number of messages that can
|
|
* be sent at once */
|
|
if (rdwr_arg.nmsgs > I2C_RDRW_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);
|
|
|
|
data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
|
|
if (data_ptrs == NULL) {
|
|
kfree(rdwr_pa);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
res = 0;
|
|
for (i = 0; i < rdwr_arg.nmsgs; i++) {
|
|
/* Limit the size of the message to a sane amount */
|
|
if (rdwr_pa[i].len > 8192) {
|
|
res = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
|
|
rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len);
|
|
if (IS_ERR(rdwr_pa[i].buf)) {
|
|
res = PTR_ERR(rdwr_pa[i].buf);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* 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 (rdwr_pa[i].flags & I2C_M_RECV_LEN) {
|
|
if (!(rdwr_pa[i].flags & I2C_M_RD) ||
|
|
rdwr_pa[i].buf[0] < 1 ||
|
|
rdwr_pa[i].len < rdwr_pa[i].buf[0] +
|
|
I2C_SMBUS_BLOCK_MAX) {
|
|
res = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
rdwr_pa[i].len = rdwr_pa[i].buf[0];
|
|
}
|
|
}
|
|
if (res < 0) {
|
|
int j;
|
|
for (j = 0; j < i; ++j)
|
|
kfree(rdwr_pa[j].buf);
|
|
kfree(data_ptrs);
|
|
kfree(rdwr_pa);
|
|
return res;
|
|
}
|
|
|
|
res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs);
|
|
while (i-- > 0) {
|
|
if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) {
|
|
if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf,
|
|
rdwr_pa[i].len))
|
|
res = -EFAULT;
|
|
}
|
|
kfree(rdwr_pa[i].buf);
|
|
}
|
|
kfree(data_ptrs);
|
|
kfree(rdwr_pa);
|
|
return res;
|
|
}
|
|
|
|
static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
|
|
unsigned long arg)
|
|
{
|
|
struct i2c_smbus_ioctl_data data_arg;
|
|
union i2c_smbus_data temp;
|
|
int datasize, res;
|
|
|
|
if (copy_from_user(&data_arg,
|
|
(struct i2c_smbus_ioctl_data __user *) arg,
|
|
sizeof(struct i2c_smbus_ioctl_data)))
|
|
return -EFAULT;
|
|
if ((data_arg.size != I2C_SMBUS_BYTE) &&
|
|
(data_arg.size != I2C_SMBUS_QUICK) &&
|
|
(data_arg.size != I2C_SMBUS_BYTE_DATA) &&
|
|
(data_arg.size != I2C_SMBUS_WORD_DATA) &&
|
|
(data_arg.size != I2C_SMBUS_PROC_CALL) &&
|
|
(data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
|
|
(data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
|
|
(data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
|
|
(data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
|
|
dev_dbg(&client->adapter->dev,
|
|
"size out of range (%x) in ioctl I2C_SMBUS.\n",
|
|
data_arg.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 ((data_arg.read_write != I2C_SMBUS_READ) &&
|
|
(data_arg.read_write != I2C_SMBUS_WRITE)) {
|
|
dev_dbg(&client->adapter->dev,
|
|
"read_write out of range (%x) in ioctl I2C_SMBUS.\n",
|
|
data_arg.read_write);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Note that command values are always valid! */
|
|
|
|
if ((data_arg.size == I2C_SMBUS_QUICK) ||
|
|
((data_arg.size == I2C_SMBUS_BYTE) &&
|
|
(data_arg.read_write == I2C_SMBUS_WRITE)))
|
|
/* These are special: we do not use data */
|
|
return i2c_smbus_xfer(client->adapter, client->addr,
|
|
client->flags, data_arg.read_write,
|
|
data_arg.command, data_arg.size, NULL);
|
|
|
|
if (data_arg.data == NULL) {
|
|
dev_dbg(&client->adapter->dev,
|
|
"data is NULL pointer in ioctl I2C_SMBUS.\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
|
|
(data_arg.size == I2C_SMBUS_BYTE))
|
|
datasize = sizeof(data_arg.data->byte);
|
|
else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
|
|
(data_arg.size == I2C_SMBUS_PROC_CALL))
|
|
datasize = sizeof(data_arg.data->word);
|
|
else /* size == smbus block, i2c block, or block proc. call */
|
|
datasize = sizeof(data_arg.data->block);
|
|
|
|
if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
|
|
(data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
|
|
(data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
|
|
(data_arg.read_write == I2C_SMBUS_WRITE)) {
|
|
if (copy_from_user(&temp, data_arg.data, datasize))
|
|
return -EFAULT;
|
|
}
|
|
if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
|
|
/* Convert old I2C block commands to the new
|
|
convention. This preserves binary compatibility. */
|
|
data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
|
|
if (data_arg.read_write == I2C_SMBUS_READ)
|
|
temp.block[0] = I2C_SMBUS_BLOCK_MAX;
|
|
}
|
|
res = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
|
|
data_arg.read_write, data_arg.command, data_arg.size, &temp);
|
|
if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
|
|
(data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
|
|
(data_arg.read_write == I2C_SMBUS_READ))) {
|
|
if (copy_to_user(data_arg.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:
|
|
/* NOTE: devices set up to work with "new style" drivers
|
|
* can't use I2C_SLAVE, even when the device node is not
|
|
* bound to a driver. Only I2C_SLAVE_FORCE will work.
|
|
*
|
|
* 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 > 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:
|
|
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:
|
|
return i2cdev_ioctl_rdrw(client, arg);
|
|
|
|
case I2C_SMBUS:
|
|
return i2cdev_ioctl_smbus(client, arg);
|
|
|
|
case I2C_RETRIES:
|
|
client->adapter->retries = arg;
|
|
break;
|
|
case I2C_TIMEOUT:
|
|
/* 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;
|
|
}
|
|
|
|
static int i2cdev_open(struct inode *inode, struct file *file)
|
|
{
|
|
unsigned int minor = iminor(inode);
|
|
struct i2c_client *client;
|
|
struct i2c_adapter *adap;
|
|
struct i2c_dev *i2c_dev;
|
|
|
|
i2c_dev = i2c_dev_get_by_minor(minor);
|
|
if (!i2c_dev)
|
|
return -ENODEV;
|
|
|
|
adap = i2c_get_adapter(i2c_dev->adap->nr);
|
|
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,
|
|
.open = i2cdev_open,
|
|
.release = i2cdev_release,
|
|
};
|
|
|
|
/* ------------------------------------------------------------------------- */
|
|
|
|
static struct class *i2c_dev_class;
|
|
|
|
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);
|
|
|
|
/* register this i2c device with the driver core */
|
|
i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
|
|
MKDEV(I2C_MAJOR, adap->nr), NULL,
|
|
"i2c-%d", adap->nr);
|
|
if (IS_ERR(i2c_dev->dev)) {
|
|
res = PTR_ERR(i2c_dev->dev);
|
|
goto error;
|
|
}
|
|
res = device_create_file(i2c_dev->dev, &dev_attr_name);
|
|
if (res)
|
|
goto error_destroy;
|
|
|
|
pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
|
|
adap->name, adap->nr);
|
|
return 0;
|
|
error_destroy:
|
|
device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
|
|
error:
|
|
return_i2c_dev(i2c_dev);
|
|
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;
|
|
|
|
device_remove_file(i2c_dev->dev, &dev_attr_name);
|
|
return_i2c_dev(i2c_dev);
|
|
device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
|
|
|
|
pr_debug("i2c-dev: 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;
|
|
|
|
printk(KERN_INFO "i2c /dev entries driver\n");
|
|
|
|
res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops);
|
|
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;
|
|
}
|
|
|
|
/* 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(I2C_MAJOR, "i2c");
|
|
out:
|
|
printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
|
|
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(I2C_MAJOR, "i2c");
|
|
}
|
|
|
|
MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
|
|
"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);
|