526 lines
13 KiB
C
526 lines
13 KiB
C
/*
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i2c-dev.c - i2c-bus driver, char device interface
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Copyright (C) 1995-97 Simon G. Vogl
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Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
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Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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/* Note that this is a complete rewrite of Simon Vogl's i2c-dev module.
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But I have used so much of his original code and ideas that it seems
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only fair to recognize him as co-author -- Frodo */
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/* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/smp_lock.h>
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#include <linux/init.h>
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#include <linux/i2c.h>
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#include <linux/i2c-dev.h>
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#include <linux/platform_device.h>
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#include <asm/uaccess.h>
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static struct i2c_client i2cdev_client_template;
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struct i2c_dev {
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int minor;
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struct i2c_adapter *adap;
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struct class_device *class_dev;
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};
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#define to_i2c_dev(d) container_of(d, struct i2c_dev, class_dev)
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#define I2C_MINORS 256
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static struct i2c_dev *i2c_dev_array[I2C_MINORS];
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static DEFINE_SPINLOCK(i2c_dev_array_lock);
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static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
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{
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struct i2c_dev *i2c_dev;
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spin_lock(&i2c_dev_array_lock);
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i2c_dev = i2c_dev_array[index];
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spin_unlock(&i2c_dev_array_lock);
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return i2c_dev;
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}
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static struct i2c_dev *i2c_dev_get_by_adapter(struct i2c_adapter *adap)
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{
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struct i2c_dev *i2c_dev = NULL;
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spin_lock(&i2c_dev_array_lock);
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if ((i2c_dev_array[adap->nr]) &&
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(i2c_dev_array[adap->nr]->adap == adap))
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i2c_dev = i2c_dev_array[adap->nr];
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spin_unlock(&i2c_dev_array_lock);
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return i2c_dev;
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}
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static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
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{
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struct i2c_dev *i2c_dev;
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i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
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if (!i2c_dev)
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return ERR_PTR(-ENOMEM);
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spin_lock(&i2c_dev_array_lock);
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if (i2c_dev_array[adap->nr]) {
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spin_unlock(&i2c_dev_array_lock);
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dev_err(&adap->dev, "i2c-dev already has a device assigned to this adapter\n");
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goto error;
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}
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i2c_dev->minor = adap->nr;
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i2c_dev_array[adap->nr] = i2c_dev;
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spin_unlock(&i2c_dev_array_lock);
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return i2c_dev;
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error:
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kfree(i2c_dev);
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return ERR_PTR(-ENODEV);
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}
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static void return_i2c_dev(struct i2c_dev *i2c_dev)
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{
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spin_lock(&i2c_dev_array_lock);
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i2c_dev_array[i2c_dev->minor] = NULL;
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spin_unlock(&i2c_dev_array_lock);
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}
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static ssize_t show_adapter_name(struct class_device *class_dev, char *buf)
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{
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struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(class_dev->devt));
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if (!i2c_dev)
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return -ENODEV;
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return sprintf(buf, "%s\n", i2c_dev->adap->name);
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}
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static CLASS_DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
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static ssize_t i2cdev_read (struct file *file, char __user *buf, size_t count,
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loff_t *offset)
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{
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char *tmp;
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int ret;
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struct i2c_client *client = (struct i2c_client *)file->private_data;
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if (count > 8192)
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count = 8192;
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tmp = kmalloc(count,GFP_KERNEL);
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if (tmp==NULL)
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return -ENOMEM;
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pr_debug("i2c-dev: i2c-%d reading %zd bytes.\n",
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iminor(file->f_dentry->d_inode), count);
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ret = i2c_master_recv(client,tmp,count);
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if (ret >= 0)
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ret = copy_to_user(buf,tmp,count)?-EFAULT:ret;
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kfree(tmp);
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return ret;
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}
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static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t count,
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loff_t *offset)
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{
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int ret;
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char *tmp;
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struct i2c_client *client = (struct i2c_client *)file->private_data;
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if (count > 8192)
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count = 8192;
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tmp = kmalloc(count,GFP_KERNEL);
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if (tmp==NULL)
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return -ENOMEM;
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if (copy_from_user(tmp,buf,count)) {
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kfree(tmp);
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return -EFAULT;
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}
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pr_debug("i2c-dev: i2c-%d writing %zd bytes.\n",
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iminor(file->f_dentry->d_inode), count);
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ret = i2c_master_send(client,tmp,count);
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kfree(tmp);
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return ret;
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}
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static int i2cdev_ioctl(struct inode *inode, struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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struct i2c_client *client = (struct i2c_client *)file->private_data;
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struct i2c_rdwr_ioctl_data rdwr_arg;
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struct i2c_smbus_ioctl_data data_arg;
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union i2c_smbus_data temp;
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struct i2c_msg *rdwr_pa;
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u8 __user **data_ptrs;
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int i,datasize,res;
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unsigned long funcs;
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dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
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cmd, arg);
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switch ( cmd ) {
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case I2C_SLAVE:
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case I2C_SLAVE_FORCE:
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if ((arg > 0x3ff) ||
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(((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
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return -EINVAL;
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if ((cmd == I2C_SLAVE) && i2c_check_addr(client->adapter,arg))
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return -EBUSY;
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client->addr = arg;
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return 0;
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case I2C_TENBIT:
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if (arg)
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client->flags |= I2C_M_TEN;
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else
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client->flags &= ~I2C_M_TEN;
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return 0;
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case I2C_PEC:
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if (arg)
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client->flags |= I2C_CLIENT_PEC;
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else
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client->flags &= ~I2C_CLIENT_PEC;
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return 0;
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case I2C_FUNCS:
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funcs = i2c_get_functionality(client->adapter);
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return (copy_to_user((unsigned long __user *)arg, &funcs,
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sizeof(unsigned long)))?-EFAULT:0;
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case I2C_RDWR:
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if (copy_from_user(&rdwr_arg,
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(struct i2c_rdwr_ioctl_data __user *)arg,
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sizeof(rdwr_arg)))
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return -EFAULT;
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/* Put an arbitrary limit on the number of messages that can
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* be sent at once */
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if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
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return -EINVAL;
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rdwr_pa = (struct i2c_msg *)
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kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
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GFP_KERNEL);
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if (rdwr_pa == NULL) return -ENOMEM;
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if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
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rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
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kfree(rdwr_pa);
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return -EFAULT;
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}
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data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
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if (data_ptrs == NULL) {
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kfree(rdwr_pa);
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return -ENOMEM;
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}
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res = 0;
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for( i=0; i<rdwr_arg.nmsgs; i++ ) {
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/* Limit the size of the message to a sane amount */
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if (rdwr_pa[i].len > 8192) {
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res = -EINVAL;
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break;
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}
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data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
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rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
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if(rdwr_pa[i].buf == NULL) {
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res = -ENOMEM;
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break;
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}
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if(copy_from_user(rdwr_pa[i].buf,
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data_ptrs[i],
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rdwr_pa[i].len)) {
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++i; /* Needs to be kfreed too */
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res = -EFAULT;
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break;
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}
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}
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if (res < 0) {
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int j;
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for (j = 0; j < i; ++j)
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kfree(rdwr_pa[j].buf);
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kfree(data_ptrs);
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kfree(rdwr_pa);
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return res;
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}
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res = i2c_transfer(client->adapter,
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rdwr_pa,
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rdwr_arg.nmsgs);
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while(i-- > 0) {
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if( res>=0 && (rdwr_pa[i].flags & I2C_M_RD)) {
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if(copy_to_user(
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data_ptrs[i],
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rdwr_pa[i].buf,
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rdwr_pa[i].len)) {
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res = -EFAULT;
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}
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}
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kfree(rdwr_pa[i].buf);
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}
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kfree(data_ptrs);
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kfree(rdwr_pa);
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return res;
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case I2C_SMBUS:
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if (copy_from_user(&data_arg,
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(struct i2c_smbus_ioctl_data __user *) arg,
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sizeof(struct i2c_smbus_ioctl_data)))
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return -EFAULT;
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if ((data_arg.size != I2C_SMBUS_BYTE) &&
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(data_arg.size != I2C_SMBUS_QUICK) &&
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(data_arg.size != I2C_SMBUS_BYTE_DATA) &&
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(data_arg.size != I2C_SMBUS_WORD_DATA) &&
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(data_arg.size != I2C_SMBUS_PROC_CALL) &&
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(data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
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(data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
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(data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
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dev_dbg(&client->adapter->dev,
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"size out of range (%x) in ioctl I2C_SMBUS.\n",
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data_arg.size);
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return -EINVAL;
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}
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/* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
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so the check is valid if size==I2C_SMBUS_QUICK too. */
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if ((data_arg.read_write != I2C_SMBUS_READ) &&
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(data_arg.read_write != I2C_SMBUS_WRITE)) {
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dev_dbg(&client->adapter->dev,
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"read_write out of range (%x) in ioctl I2C_SMBUS.\n",
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data_arg.read_write);
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return -EINVAL;
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}
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/* Note that command values are always valid! */
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if ((data_arg.size == I2C_SMBUS_QUICK) ||
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((data_arg.size == I2C_SMBUS_BYTE) &&
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(data_arg.read_write == I2C_SMBUS_WRITE)))
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/* These are special: we do not use data */
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return i2c_smbus_xfer(client->adapter, client->addr,
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client->flags,
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data_arg.read_write,
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data_arg.command,
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data_arg.size, NULL);
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if (data_arg.data == NULL) {
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dev_dbg(&client->adapter->dev,
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"data is NULL pointer in ioctl I2C_SMBUS.\n");
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return -EINVAL;
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}
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if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
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(data_arg.size == I2C_SMBUS_BYTE))
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datasize = sizeof(data_arg.data->byte);
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else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
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(data_arg.size == I2C_SMBUS_PROC_CALL))
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datasize = sizeof(data_arg.data->word);
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else /* size == smbus block, i2c block, or block proc. call */
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datasize = sizeof(data_arg.data->block);
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if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
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(data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
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(data_arg.read_write == I2C_SMBUS_WRITE)) {
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if (copy_from_user(&temp, data_arg.data, datasize))
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return -EFAULT;
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}
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res = i2c_smbus_xfer(client->adapter,client->addr,client->flags,
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data_arg.read_write,
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data_arg.command,data_arg.size,&temp);
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if (! res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
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(data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
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(data_arg.read_write == I2C_SMBUS_READ))) {
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if (copy_to_user(data_arg.data, &temp, datasize))
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return -EFAULT;
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}
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return res;
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default:
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return i2c_control(client,cmd,arg);
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}
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return 0;
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}
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static int i2cdev_open(struct inode *inode, struct file *file)
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{
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unsigned int minor = iminor(inode);
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struct i2c_client *client;
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struct i2c_adapter *adap;
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struct i2c_dev *i2c_dev;
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i2c_dev = i2c_dev_get_by_minor(minor);
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if (!i2c_dev)
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return -ENODEV;
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adap = i2c_get_adapter(i2c_dev->adap->nr);
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if (!adap)
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return -ENODEV;
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client = kmalloc(sizeof(*client), GFP_KERNEL);
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if (!client) {
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i2c_put_adapter(adap);
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return -ENOMEM;
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}
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memcpy(client, &i2cdev_client_template, sizeof(*client));
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/* registered with adapter, passed as client to user */
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client->adapter = adap;
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file->private_data = client;
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return 0;
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}
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static int i2cdev_release(struct inode *inode, struct file *file)
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{
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struct i2c_client *client = file->private_data;
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i2c_put_adapter(client->adapter);
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kfree(client);
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file->private_data = NULL;
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return 0;
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}
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static struct file_operations i2cdev_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.read = i2cdev_read,
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.write = i2cdev_write,
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.ioctl = i2cdev_ioctl,
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.open = i2cdev_open,
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.release = i2cdev_release,
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};
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static struct class *i2c_dev_class;
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static int i2cdev_attach_adapter(struct i2c_adapter *adap)
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{
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struct i2c_dev *i2c_dev;
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struct device *dev;
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i2c_dev = get_free_i2c_dev(adap);
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if (IS_ERR(i2c_dev))
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return PTR_ERR(i2c_dev);
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pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
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adap->name, i2c_dev->minor);
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/* register this i2c device with the driver core */
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i2c_dev->adap = adap;
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if (adap->dev.parent == &platform_bus)
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dev = &adap->dev;
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else
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dev = adap->dev.parent;
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i2c_dev->class_dev = class_device_create(i2c_dev_class, NULL,
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MKDEV(I2C_MAJOR, i2c_dev->minor),
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dev, "i2c-%d", i2c_dev->minor);
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if (!i2c_dev->class_dev)
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goto error;
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class_device_create_file(i2c_dev->class_dev, &class_device_attr_name);
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return 0;
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error:
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return_i2c_dev(i2c_dev);
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kfree(i2c_dev);
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return -ENODEV;
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}
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static int i2cdev_detach_adapter(struct i2c_adapter *adap)
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{
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struct i2c_dev *i2c_dev;
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i2c_dev = i2c_dev_get_by_adapter(adap);
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if (!i2c_dev)
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return -ENODEV;
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return_i2c_dev(i2c_dev);
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class_device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, i2c_dev->minor));
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kfree(i2c_dev);
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pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
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return 0;
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}
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static int i2cdev_detach_client(struct i2c_client *client)
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{
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return 0;
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}
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static struct i2c_driver i2cdev_driver = {
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.driver = {
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.name = "dev_driver",
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},
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.id = I2C_DRIVERID_I2CDEV,
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.attach_adapter = i2cdev_attach_adapter,
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.detach_adapter = i2cdev_detach_adapter,
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.detach_client = i2cdev_detach_client,
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};
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static struct i2c_client i2cdev_client_template = {
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.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;
|
|
|
|
i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
|
|
if (IS_ERR(i2c_dev_class))
|
|
goto out_unreg_chrdev;
|
|
|
|
res = i2c_add_driver(&i2cdev_driver);
|
|
if (res)
|
|
goto out_unreg_class;
|
|
|
|
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)
|
|
{
|
|
i2c_del_driver(&i2cdev_driver);
|
|
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);
|