/*
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., 675 Mass Ave, Cambridge, MA 02139, 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> */
/* The devfs code is contributed by Philipp Matthias Hahn
<pmhahn@titan.lahn.de> */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
#include <asm/uaccess.h>
static struct i2c_client i2cdev_client_template;
struct i2c_dev {
int minor;
struct i2c_adapter *adap;
struct class_device class_dev;
struct completion released; /* FIXME, we need a class_device_unregister() */
};
#define to_i2c_dev(d) container_of(d, struct i2c_dev, class_dev)
#define I2C_MINORS 256
static struct i2c_dev *i2c_dev_array[I2C_MINORS];
static DEFINE_SPINLOCK(i2c_dev_array_lock);
static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
{
struct i2c_dev *i2c_dev;
spin_lock(&i2c_dev_array_lock);
i2c_dev = i2c_dev_array[index];
spin_unlock(&i2c_dev_array_lock);
return i2c_dev;
}
static struct i2c_dev *i2c_dev_get_by_adapter(struct i2c_adapter *adap)
{
struct i2c_dev *i2c_dev = NULL;
spin_lock(&i2c_dev_array_lock);
if ((i2c_dev_array[adap->nr]) &&
(i2c_dev_array[adap->nr]->adap == adap))
i2c_dev = i2c_dev_array[adap->nr];
spin_unlock(&i2c_dev_array_lock);
return i2c_dev;
}
static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
{
struct i2c_dev *i2c_dev;
i2c_dev = kmalloc(sizeof(*i2c_dev), GFP_KERNEL);
if (!i2c_dev)
return ERR_PTR(-ENOMEM);
memset(i2c_dev, 0x00, sizeof(*i2c_dev));
spin_lock(&i2c_dev_array_lock);
if (i2c_dev_array[adap->nr]) {
spin_unlock(&i2c_dev_array_lock);
dev_err(&adap->dev, "i2c-dev already has a device assigned to this adapter\n");
goto error;
}
i2c_dev->minor = adap->nr;
i2c_dev_array[adap->nr] = i2c_dev;
spin_unlock(&i2c_dev_array_lock);
return i2c_dev;
error:
kfree(i2c_dev);
return ERR_PTR(-ENODEV);
}
static void return_i2c_dev(struct i2c_dev *i2c_dev)
{
spin_lock(&i2c_dev_array_lock);
i2c_dev_array[i2c_dev->minor] = NULL;
spin_unlock(&i2c_dev_array_lock);
}
static ssize_t show_adapter_name(struct class_device *class_dev, char *buf)
{
struct i2c_dev *i2c_dev = to_i2c_dev(class_dev);
return sprintf(buf, "%s\n", i2c_dev->adap->name);
}
static CLASS_DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
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 = (struct i2c_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 %zd bytes.\n",
iminor(file->f_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 = (struct i2c_client *)file->private_data;
if (count > 8192)
count = 8192;
tmp = kmalloc(count,GFP_KERNEL);
if (tmp==NULL)
return -ENOMEM;
if (copy_from_user(tmp,buf,count)) {
kfree(tmp);
return -EFAULT;
}
pr_debug("i2c-dev: i2c-%d writing %zd bytes.\n",
iminor(file->f_dentry->d_inode), count);
ret = i2c_master_send(client,tmp,count);
kfree(tmp);
return ret;
}
static int i2cdev_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct i2c_client *client = (struct i2c_client *)file->private_data;
struct i2c_rdwr_ioctl_data rdwr_arg;
struct i2c_smbus_ioctl_data data_arg;
union i2c_smbus_data temp;
struct i2c_msg *rdwr_pa;
u8 __user **data_ptrs;
int i,datasize,res;
unsigned long funcs;
dev_dbg(&client->adapter->dev, "i2c-%d ioctl, cmd: 0x%x, arg: %lx.\n",
iminor(inode),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) && i2c_check_addr(client->adapter,arg))
return -EBUSY;
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 (copy_to_user((unsigned long __user *)arg, &funcs,
sizeof(unsigned long)))?-EFAULT:0;
case I2C_RDWR:
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 = (struct i2c_msg *)
kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
GFP_KERNEL);
if (rdwr_pa == NULL) return -ENOMEM;
if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
kfree(rdwr_pa);
return -EFAULT;
}
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 = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
if(rdwr_pa[i].buf == NULL) {
res = -ENOMEM;
break;
}
if(copy_from_user(rdwr_pa[i].buf,
data_ptrs[i],
rdwr_pa[i].len)) {
++i; /* Needs to be kfreed too */
res = -EFAULT;
break;
}
}
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;
case I2C_SMBUS:
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_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.read_write == I2C_SMBUS_WRITE)) {
if (copy_from_user(&temp, data_arg.data, datasize))
return -EFAULT;
}
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;
default:
return i2c_control(client,cmd,arg);
}
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;
client = kmalloc(sizeof(*client), GFP_KERNEL);
if (!client) {
i2c_put_adapter(adap);
return -ENOMEM;
}
memcpy(client, &i2cdev_client_template, sizeof(*client));
/* registered with adapter, passed as client to user */
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 struct file_operations i2cdev_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = i2cdev_read,
.write = i2cdev_write,
.ioctl = i2cdev_ioctl,
.open = i2cdev_open,
.release = i2cdev_release,
};
static void release_i2c_dev(struct class_device *dev)
{
struct i2c_dev *i2c_dev = to_i2c_dev(dev);
complete(&i2c_dev->released);
}
static struct class i2c_dev_class = {
.name = "i2c-dev",
.release = &release_i2c_dev,
};
static int i2cdev_attach_adapter(struct i2c_adapter *adap)
{
struct i2c_dev *i2c_dev;
int retval;
i2c_dev = get_free_i2c_dev(adap);
if (IS_ERR(i2c_dev))
return PTR_ERR(i2c_dev);
devfs_mk_cdev(MKDEV(I2C_MAJOR, i2c_dev->minor),
S_IFCHR|S_IRUSR|S_IWUSR, "i2c/%d", i2c_dev->minor);
dev_dbg(&adap->dev, "Registered as minor %d\n", i2c_dev->minor);
/* register this i2c device with the driver core */
i2c_dev->adap = adap;
if (adap->dev.parent == &platform_bus)
i2c_dev->class_dev.dev = &adap->dev;
else
i2c_dev->class_dev.dev = adap->dev.parent;
i2c_dev->class_dev.class = &i2c_dev_class;
i2c_dev->class_dev.devt = MKDEV(I2C_MAJOR, i2c_dev->minor);
snprintf(i2c_dev->class_dev.class_id, BUS_ID_SIZE, "i2c-%d", i2c_dev->minor);
retval = class_device_register(&i2c_dev->class_dev);
if (retval)
goto error;
class_device_create_file(&i2c_dev->class_dev, &class_device_attr_name);
return 0;
error:
return_i2c_dev(i2c_dev);
kfree(i2c_dev);
return retval;
}
static int i2cdev_detach_adapter(struct i2c_adapter *adap)
{
struct i2c_dev *i2c_dev;
i2c_dev = i2c_dev_get_by_adapter(adap);
if (!i2c_dev)
return -ENODEV;
init_completion(&i2c_dev->released);
devfs_remove("i2c/%d", i2c_dev->minor);
return_i2c_dev(i2c_dev);
class_device_unregister(&i2c_dev->class_dev);
wait_for_completion(&i2c_dev->released);
kfree(i2c_dev);
dev_dbg(&adap->dev, "Adapter unregistered\n");
return 0;
}
static int i2cdev_detach_client(struct i2c_client *client)
{
return 0;
}
static int i2cdev_command(struct i2c_client *client, unsigned int cmd,
void *arg)
{
return -1;
}
static struct i2c_driver i2cdev_driver = {
.owner = THIS_MODULE,
.name = "dev_driver",
.id = I2C_DRIVERID_I2CDEV,
.flags = I2C_DF_NOTIFY,
.attach_adapter = i2cdev_attach_adapter,
.detach_adapter = i2cdev_detach_adapter,
.detach_client = i2cdev_detach_client,
.command = i2cdev_command,
};
static struct i2c_client i2cdev_client_template = {
.name = "I2C /dev entry",
.addr = -1,
.driver = &i2cdev_driver,
};
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;
res = class_register(&i2c_dev_class);
if (res)
goto out_unreg_chrdev;
res = i2c_add_driver(&i2cdev_driver);
if (res)
goto out_unreg_class;
devfs_mk_dir("i2c");
return 0;
out_unreg_class:
class_unregister(&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)
{
i2c_del_driver(&i2cdev_driver);
class_unregister(&i2c_dev_class);
devfs_remove("i2c");
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);
