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/*
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> */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
#include <linux/platform_device.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;
};
#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 = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
if (!i2c_dev)
return ERR_PTR(-ENOMEM);
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 = i2c_dev_get_by_minor(MINOR(class_dev->devt));
if (!i2c_dev)
return -ENODEV;
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, "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) && 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)
|