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62 |
marcus.erl |
/*
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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/init.h>
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#include <linux/list.h>
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#include <linux/i2c.h>
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#include <linux/i2c-dev.h>
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#include <asm/uaccess.h>
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static struct i2c_driver i2cdev_driver;
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/*
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* An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a
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* slave (i2c_client) with which messages will be exchanged. It's coupled
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* with a character special file which is accessed by user mode drivers.
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*
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* The list of i2c_dev structures is parallel to the i2c_adapter lists
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* maintained by the driver model, and is updated using notifications
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* delivered to the i2cdev_driver.
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*/
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struct i2c_dev {
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struct list_head list;
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struct i2c_adapter *adap;
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struct device *dev;
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};
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#define I2C_MINORS 256
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static LIST_HEAD(i2c_dev_list);
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static DEFINE_SPINLOCK(i2c_dev_list_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_list_lock);
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list_for_each_entry(i2c_dev, &i2c_dev_list, list) {
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if (i2c_dev->adap->nr == index)
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goto found;
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}
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i2c_dev = NULL;
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found:
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spin_unlock(&i2c_dev_list_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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if (adap->nr >= I2C_MINORS) {
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printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
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adap->nr);
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return ERR_PTR(-ENODEV);
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}
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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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i2c_dev->adap = adap;
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| 90 |
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spin_lock(&i2c_dev_list_lock);
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list_add_tail(&i2c_dev->list, &i2c_dev_list);
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spin_unlock(&i2c_dev_list_lock);
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return i2c_dev;
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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_list_lock);
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list_del(&i2c_dev->list);
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spin_unlock(&i2c_dev_list_lock);
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kfree(i2c_dev);
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}
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| 104 |
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static ssize_t show_adapter_name(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(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 DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
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/* ------------------------------------------------------------------------- */
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/*
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* After opening an instance of this character special file, a file
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* descriptor starts out associated only with an i2c_adapter (and bus).
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*
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* Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg
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* traffic to any devices on the bus used by that adapter. That's because
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* the i2c_msg vectors embed all the addressing information they need, and
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* are submitted directly to an i2c_adapter. However, SMBus-only adapters
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* don't support that interface.
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*
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* To use read()/write() system calls on that file descriptor, or to use
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* SMBus interfaces (and work with SMBus-only hosts!), you must first issue
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* an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous
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* (never registered) i2c_client so it holds the addressing information
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* needed by those system calls and by this SMBus interface.
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*/
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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_path.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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| 162 |
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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_path.dentry->d_inode), count);
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| 180 |
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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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| 184 |
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| 185 |
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/* This address checking function differs from the one in i2c-core
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| 186 |
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in that it considers an address with a registered device, but no
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| 187 |
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bound driver, as NOT busy. */
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| 188 |
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static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
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{
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| 190 |
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struct list_head *item;
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| 191 |
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struct i2c_client *client;
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| 192 |
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int res = 0;
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| 193 |
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| 194 |
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mutex_lock(&adapter->clist_lock);
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| 195 |
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list_for_each(item, &adapter->clients) {
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| 196 |
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client = list_entry(item, struct i2c_client, list);
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| 197 |
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if (client->addr == addr) {
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| 198 |
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if (client->driver)
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| 199 |
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res = -EBUSY;
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| 200 |
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break;
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| 201 |
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}
|
| 202 |
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}
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| 203 |
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mutex_unlock(&adapter->clist_lock);
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| 204 |
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| 205 |
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return res;
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| 206 |
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}
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| 207 |
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| 208 |
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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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| 211 |
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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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| 215 |
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struct i2c_msg *rdwr_pa;
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| 216 |
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u8 __user **data_ptrs;
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| 217 |
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int i,datasize,res;
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| 218 |
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unsigned long funcs;
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| 219 |
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| 220 |
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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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| 222 |
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| 223 |
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switch ( cmd ) {
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| 224 |
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case I2C_SLAVE:
|
| 225 |
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case I2C_SLAVE_FORCE:
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| 226 |
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/* NOTE: devices set up to work with "new style" drivers
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| 227 |
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* can't use I2C_SLAVE, even when the device node is not
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| 228 |
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* bound to a driver. Only I2C_SLAVE_FORCE will work.
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| 229 |
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*
|
| 230 |
|
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* Setting the PEC flag here won't affect kernel drivers,
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| 231 |
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* which will be using the i2c_client node registered with
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| 232 |
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* the driver model core. Likewise, when that client has
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| 233 |
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* the PEC flag already set, the i2c-dev driver won't see
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| 234 |
|
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* (or use) this setting.
|
| 235 |
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*/
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| 236 |
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if ((arg > 0x3ff) ||
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| 237 |
|
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(((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
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| 238 |
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return -EINVAL;
|
| 239 |
|
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if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg))
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| 240 |
|
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return -EBUSY;
|
| 241 |
|
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/* REVISIT: address could become busy later */
|
| 242 |
|
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client->addr = arg;
|
| 243 |
|
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return 0;
|
| 244 |
|
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case I2C_TENBIT:
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| 245 |
|
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if (arg)
|
| 246 |
|
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client->flags |= I2C_M_TEN;
|
| 247 |
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else
|
| 248 |
|
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client->flags &= ~I2C_M_TEN;
|
| 249 |
|
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return 0;
|
| 250 |
|
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case I2C_PEC:
|
| 251 |
|
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if (arg)
|
| 252 |
|
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client->flags |= I2C_CLIENT_PEC;
|
| 253 |
|
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else
|
| 254 |
|
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client->flags &= ~I2C_CLIENT_PEC;
|
| 255 |
|
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return 0;
|
| 256 |
|
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case I2C_FUNCS:
|
| 257 |
|
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funcs = i2c_get_functionality(client->adapter);
|
| 258 |
|
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return put_user(funcs, (unsigned long __user *)arg);
|
| 259 |
|
|
|
| 260 |
|
|
case I2C_RDWR:
|
| 261 |
|
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if (copy_from_user(&rdwr_arg,
|
| 262 |
|
|
(struct i2c_rdwr_ioctl_data __user *)arg,
|
| 263 |
|
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sizeof(rdwr_arg)))
|
| 264 |
|
|
return -EFAULT;
|
| 265 |
|
|
|
| 266 |
|
|
/* Put an arbitrary limit on the number of messages that can
|
| 267 |
|
|
* be sent at once */
|
| 268 |
|
|
if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
|
| 269 |
|
|
return -EINVAL;
|
| 270 |
|
|
|
| 271 |
|
|
rdwr_pa = (struct i2c_msg *)
|
| 272 |
|
|
kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
|
| 273 |
|
|
GFP_KERNEL);
|
| 274 |
|
|
|
| 275 |
|
|
if (rdwr_pa == NULL) return -ENOMEM;
|
| 276 |
|
|
|
| 277 |
|
|
if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
|
| 278 |
|
|
rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
|
| 279 |
|
|
kfree(rdwr_pa);
|
| 280 |
|
|
return -EFAULT;
|
| 281 |
|
|
}
|
| 282 |
|
|
|
| 283 |
|
|
data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
|
| 284 |
|
|
if (data_ptrs == NULL) {
|
| 285 |
|
|
kfree(rdwr_pa);
|
| 286 |
|
|
return -ENOMEM;
|
| 287 |
|
|
}
|
| 288 |
|
|
|
| 289 |
|
|
res = 0;
|
| 290 |
|
|
for( i=0; i<rdwr_arg.nmsgs; i++ ) {
|
| 291 |
|
|
/* Limit the size of the message to a sane amount;
|
| 292 |
|
|
* and don't let length change either. */
|
| 293 |
|
|
if ((rdwr_pa[i].len > 8192) ||
|
| 294 |
|
|
(rdwr_pa[i].flags & I2C_M_RECV_LEN)) {
|
| 295 |
|
|
res = -EINVAL;
|
| 296 |
|
|
break;
|
| 297 |
|
|
}
|
| 298 |
|
|
data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
|
| 299 |
|
|
rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
|
| 300 |
|
|
if(rdwr_pa[i].buf == NULL) {
|
| 301 |
|
|
res = -ENOMEM;
|
| 302 |
|
|
break;
|
| 303 |
|
|
}
|
| 304 |
|
|
if(copy_from_user(rdwr_pa[i].buf,
|
| 305 |
|
|
data_ptrs[i],
|
| 306 |
|
|
rdwr_pa[i].len)) {
|
| 307 |
|
|
++i; /* Needs to be kfreed too */
|
| 308 |
|
|
res = -EFAULT;
|
| 309 |
|
|
break;
|
| 310 |
|
|
}
|
| 311 |
|
|
}
|
| 312 |
|
|
if (res < 0) {
|
| 313 |
|
|
int j;
|
| 314 |
|
|
for (j = 0; j < i; ++j)
|
| 315 |
|
|
kfree(rdwr_pa[j].buf);
|
| 316 |
|
|
kfree(data_ptrs);
|
| 317 |
|
|
kfree(rdwr_pa);
|
| 318 |
|
|
return res;
|
| 319 |
|
|
}
|
| 320 |
|
|
|
| 321 |
|
|
res = i2c_transfer(client->adapter,
|
| 322 |
|
|
rdwr_pa,
|
| 323 |
|
|
rdwr_arg.nmsgs);
|
| 324 |
|
|
while(i-- > 0) {
|
| 325 |
|
|
if( res>=0 && (rdwr_pa[i].flags & I2C_M_RD)) {
|
| 326 |
|
|
if(copy_to_user(
|
| 327 |
|
|
data_ptrs[i],
|
| 328 |
|
|
rdwr_pa[i].buf,
|
| 329 |
|
|
rdwr_pa[i].len)) {
|
| 330 |
|
|
res = -EFAULT;
|
| 331 |
|
|
}
|
| 332 |
|
|
}
|
| 333 |
|
|
kfree(rdwr_pa[i].buf);
|
| 334 |
|
|
}
|
| 335 |
|
|
kfree(data_ptrs);
|
| 336 |
|
|
kfree(rdwr_pa);
|
| 337 |
|
|
return res;
|
| 338 |
|
|
|
| 339 |
|
|
case I2C_SMBUS:
|
| 340 |
|
|
if (copy_from_user(&data_arg,
|
| 341 |
|
|
(struct i2c_smbus_ioctl_data __user *) arg,
|
| 342 |
|
|
sizeof(struct i2c_smbus_ioctl_data)))
|
| 343 |
|
|
return -EFAULT;
|
| 344 |
|
|
if ((data_arg.size != I2C_SMBUS_BYTE) &&
|
| 345 |
|
|
(data_arg.size != I2C_SMBUS_QUICK) &&
|
| 346 |
|
|
(data_arg.size != I2C_SMBUS_BYTE_DATA) &&
|
| 347 |
|
|
(data_arg.size != I2C_SMBUS_WORD_DATA) &&
|
| 348 |
|
|
(data_arg.size != I2C_SMBUS_PROC_CALL) &&
|
| 349 |
|
|
(data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
|
| 350 |
|
|
(data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
|
| 351 |
|
|
(data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
|
| 352 |
|
|
(data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
|
| 353 |
|
|
dev_dbg(&client->adapter->dev,
|
| 354 |
|
|
"size out of range (%x) in ioctl I2C_SMBUS.\n",
|
| 355 |
|
|
data_arg.size);
|
| 356 |
|
|
return -EINVAL;
|
| 357 |
|
|
}
|
| 358 |
|
|
/* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
|
| 359 |
|
|
so the check is valid if size==I2C_SMBUS_QUICK too. */
|
| 360 |
|
|
if ((data_arg.read_write != I2C_SMBUS_READ) &&
|
| 361 |
|
|
(data_arg.read_write != I2C_SMBUS_WRITE)) {
|
| 362 |
|
|
dev_dbg(&client->adapter->dev,
|
| 363 |
|
|
"read_write out of range (%x) in ioctl I2C_SMBUS.\n",
|
| 364 |
|
|
data_arg.read_write);
|
| 365 |
|
|
return -EINVAL;
|
| 366 |
|
|
}
|
| 367 |
|
|
|
| 368 |
|
|
/* Note that command values are always valid! */
|
| 369 |
|
|
|
| 370 |
|
|
if ((data_arg.size == I2C_SMBUS_QUICK) ||
|
| 371 |
|
|
((data_arg.size == I2C_SMBUS_BYTE) &&
|
| 372 |
|
|
(data_arg.read_write == I2C_SMBUS_WRITE)))
|
| 373 |
|
|
/* These are special: we do not use data */
|
| 374 |
|
|
return i2c_smbus_xfer(client->adapter, client->addr,
|
| 375 |
|
|
client->flags,
|
| 376 |
|
|
data_arg.read_write,
|
| 377 |
|
|
data_arg.command,
|
| 378 |
|
|
data_arg.size, NULL);
|
| 379 |
|
|
|
| 380 |
|
|
if (data_arg.data == NULL) {
|
| 381 |
|
|
dev_dbg(&client->adapter->dev,
|
| 382 |
|
|
"data is NULL pointer in ioctl I2C_SMBUS.\n");
|
| 383 |
|
|
return -EINVAL;
|
| 384 |
|
|
}
|
| 385 |
|
|
|
| 386 |
|
|
if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
|
| 387 |
|
|
(data_arg.size == I2C_SMBUS_BYTE))
|
| 388 |
|
|
datasize = sizeof(data_arg.data->byte);
|
| 389 |
|
|
else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
|
| 390 |
|
|
(data_arg.size == I2C_SMBUS_PROC_CALL))
|
| 391 |
|
|
datasize = sizeof(data_arg.data->word);
|
| 392 |
|
|
else /* size == smbus block, i2c block, or block proc. call */
|
| 393 |
|
|
datasize = sizeof(data_arg.data->block);
|
| 394 |
|
|
|
| 395 |
|
|
if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
|
| 396 |
|
|
(data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
|
| 397 |
|
|
(data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
|
| 398 |
|
|
(data_arg.read_write == I2C_SMBUS_WRITE)) {
|
| 399 |
|
|
if (copy_from_user(&temp, data_arg.data, datasize))
|
| 400 |
|
|
return -EFAULT;
|
| 401 |
|
|
}
|
| 402 |
|
|
if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
|
| 403 |
|
|
/* Convert old I2C block commands to the new
|
| 404 |
|
|
convention. This preserves binary compatibility. */
|
| 405 |
|
|
data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
|
| 406 |
|
|
if (data_arg.read_write == I2C_SMBUS_READ)
|
| 407 |
|
|
temp.block[0] = I2C_SMBUS_BLOCK_MAX;
|
| 408 |
|
|
}
|
| 409 |
|
|
res = i2c_smbus_xfer(client->adapter,client->addr,client->flags,
|
| 410 |
|
|
data_arg.read_write,
|
| 411 |
|
|
data_arg.command,data_arg.size,&temp);
|
| 412 |
|
|
if (! res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
|
| 413 |
|
|
(data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
|
| 414 |
|
|
(data_arg.read_write == I2C_SMBUS_READ))) {
|
| 415 |
|
|
if (copy_to_user(data_arg.data, &temp, datasize))
|
| 416 |
|
|
return -EFAULT;
|
| 417 |
|
|
}
|
| 418 |
|
|
return res;
|
| 419 |
|
|
case I2C_RETRIES:
|
| 420 |
|
|
client->adapter->retries = arg;
|
| 421 |
|
|
break;
|
| 422 |
|
|
case I2C_TIMEOUT:
|
| 423 |
|
|
client->adapter->timeout = arg;
|
| 424 |
|
|
break;
|
| 425 |
|
|
default:
|
| 426 |
|
|
/* NOTE: returning a fault code here could cause trouble
|
| 427 |
|
|
* in buggy userspace code. Some old kernel bugs returned
|
| 428 |
|
|
* zero in this case, and userspace code might accidentally
|
| 429 |
|
|
* have depended on that bug.
|
| 430 |
|
|
*/
|
| 431 |
|
|
return -ENOTTY;
|
| 432 |
|
|
}
|
| 433 |
|
|
return 0;
|
| 434 |
|
|
}
|
| 435 |
|
|
|
| 436 |
|
|
static int i2cdev_open(struct inode *inode, struct file *file)
|
| 437 |
|
|
{
|
| 438 |
|
|
unsigned int minor = iminor(inode);
|
| 439 |
|
|
struct i2c_client *client;
|
| 440 |
|
|
struct i2c_adapter *adap;
|
| 441 |
|
|
struct i2c_dev *i2c_dev;
|
| 442 |
|
|
|
| 443 |
|
|
i2c_dev = i2c_dev_get_by_minor(minor);
|
| 444 |
|
|
if (!i2c_dev)
|
| 445 |
|
|
return -ENODEV;
|
| 446 |
|
|
|
| 447 |
|
|
adap = i2c_get_adapter(i2c_dev->adap->nr);
|
| 448 |
|
|
if (!adap)
|
| 449 |
|
|
return -ENODEV;
|
| 450 |
|
|
|
| 451 |
|
|
/* This creates an anonymous i2c_client, which may later be
|
| 452 |
|
|
* pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE.
|
| 453 |
|
|
*
|
| 454 |
|
|
* This client is ** NEVER REGISTERED ** with the driver model
|
| 455 |
|
|
* or I2C core code!! It just holds private copies of addressing
|
| 456 |
|
|
* information and maybe a PEC flag.
|
| 457 |
|
|
*/
|
| 458 |
|
|
client = kzalloc(sizeof(*client), GFP_KERNEL);
|
| 459 |
|
|
if (!client) {
|
| 460 |
|
|
i2c_put_adapter(adap);
|
| 461 |
|
|
return -ENOMEM;
|
| 462 |
|
|
}
|
| 463 |
|
|
snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
|
| 464 |
|
|
client->driver = &i2cdev_driver;
|
| 465 |
|
|
|
| 466 |
|
|
client->adapter = adap;
|
| 467 |
|
|
file->private_data = client;
|
| 468 |
|
|
|
| 469 |
|
|
return 0;
|
| 470 |
|
|
}
|
| 471 |
|
|
|
| 472 |
|
|
static int i2cdev_release(struct inode *inode, struct file *file)
|
| 473 |
|
|
{
|
| 474 |
|
|
struct i2c_client *client = file->private_data;
|
| 475 |
|
|
|
| 476 |
|
|
i2c_put_adapter(client->adapter);
|
| 477 |
|
|
kfree(client);
|
| 478 |
|
|
file->private_data = NULL;
|
| 479 |
|
|
|
| 480 |
|
|
return 0;
|
| 481 |
|
|
}
|
| 482 |
|
|
|
| 483 |
|
|
static const struct file_operations i2cdev_fops = {
|
| 484 |
|
|
.owner = THIS_MODULE,
|
| 485 |
|
|
.llseek = no_llseek,
|
| 486 |
|
|
.read = i2cdev_read,
|
| 487 |
|
|
.write = i2cdev_write,
|
| 488 |
|
|
.ioctl = i2cdev_ioctl,
|
| 489 |
|
|
.open = i2cdev_open,
|
| 490 |
|
|
.release = i2cdev_release,
|
| 491 |
|
|
};
|
| 492 |
|
|
|
| 493 |
|
|
/* ------------------------------------------------------------------------- */
|
| 494 |
|
|
|
| 495 |
|
|
/*
|
| 496 |
|
|
* The legacy "i2cdev_driver" is used primarily to get notifications when
|
| 497 |
|
|
* I2C adapters are added or removed, so that each one gets an i2c_dev
|
| 498 |
|
|
* and is thus made available to userspace driver code.
|
| 499 |
|
|
*/
|
| 500 |
|
|
|
| 501 |
|
|
static struct class *i2c_dev_class;
|
| 502 |
|
|
|
| 503 |
|
|
static int i2cdev_attach_adapter(struct i2c_adapter *adap)
|
| 504 |
|
|
{
|
| 505 |
|
|
struct i2c_dev *i2c_dev;
|
| 506 |
|
|
int res;
|
| 507 |
|
|
|
| 508 |
|
|
i2c_dev = get_free_i2c_dev(adap);
|
| 509 |
|
|
if (IS_ERR(i2c_dev))
|
| 510 |
|
|
return PTR_ERR(i2c_dev);
|
| 511 |
|
|
|
| 512 |
|
|
/* register this i2c device with the driver core */
|
| 513 |
|
|
i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
|
| 514 |
|
|
MKDEV(I2C_MAJOR, adap->nr),
|
| 515 |
|
|
"i2c-%d", adap->nr);
|
| 516 |
|
|
if (IS_ERR(i2c_dev->dev)) {
|
| 517 |
|
|
res = PTR_ERR(i2c_dev->dev);
|
| 518 |
|
|
goto error;
|
| 519 |
|
|
}
|
| 520 |
|
|
res = device_create_file(i2c_dev->dev, &dev_attr_name);
|
| 521 |
|
|
if (res)
|
| 522 |
|
|
goto error_destroy;
|
| 523 |
|
|
|
| 524 |
|
|
pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
|
| 525 |
|
|
adap->name, adap->nr);
|
| 526 |
|
|
return 0;
|
| 527 |
|
|
error_destroy:
|
| 528 |
|
|
device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
|
| 529 |
|
|
error:
|
| 530 |
|
|
return_i2c_dev(i2c_dev);
|
| 531 |
|
|
return res;
|
| 532 |
|
|
}
|
| 533 |
|
|
|
| 534 |
|
|
static int i2cdev_detach_adapter(struct i2c_adapter *adap)
|
| 535 |
|
|
{
|
| 536 |
|
|
struct i2c_dev *i2c_dev;
|
| 537 |
|
|
|
| 538 |
|
|
i2c_dev = i2c_dev_get_by_minor(adap->nr);
|
| 539 |
|
|
if (!i2c_dev) /* attach_adapter must have failed */
|
| 540 |
|
|
return 0;
|
| 541 |
|
|
|
| 542 |
|
|
device_remove_file(i2c_dev->dev, &dev_attr_name);
|
| 543 |
|
|
return_i2c_dev(i2c_dev);
|
| 544 |
|
|
device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
|
| 545 |
|
|
|
| 546 |
|
|
pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
|
| 547 |
|
|
return 0;
|
| 548 |
|
|
}
|
| 549 |
|
|
|
| 550 |
|
|
static int i2cdev_detach_client(struct i2c_client *client)
|
| 551 |
|
|
{
|
| 552 |
|
|
return 0;
|
| 553 |
|
|
}
|
| 554 |
|
|
|
| 555 |
|
|
static struct i2c_driver i2cdev_driver = {
|
| 556 |
|
|
.driver = {
|
| 557 |
|
|
.name = "dev_driver",
|
| 558 |
|
|
},
|
| 559 |
|
|
.id = I2C_DRIVERID_I2CDEV,
|
| 560 |
|
|
.attach_adapter = i2cdev_attach_adapter,
|
| 561 |
|
|
.detach_adapter = i2cdev_detach_adapter,
|
| 562 |
|
|
.detach_client = i2cdev_detach_client,
|
| 563 |
|
|
};
|
| 564 |
|
|
|
| 565 |
|
|
/* ------------------------------------------------------------------------- */
|
| 566 |
|
|
|
| 567 |
|
|
/*
|
| 568 |
|
|
* module load/unload record keeping
|
| 569 |
|
|
*/
|
| 570 |
|
|
|
| 571 |
|
|
static int __init i2c_dev_init(void)
|
| 572 |
|
|
{
|
| 573 |
|
|
int res;
|
| 574 |
|
|
|
| 575 |
|
|
printk(KERN_INFO "i2c /dev entries driver\n");
|
| 576 |
|
|
|
| 577 |
|
|
res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops);
|
| 578 |
|
|
if (res)
|
| 579 |
|
|
goto out;
|
| 580 |
|
|
|
| 581 |
|
|
i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
|
| 582 |
|
|
if (IS_ERR(i2c_dev_class))
|
| 583 |
|
|
goto out_unreg_chrdev;
|
| 584 |
|
|
|
| 585 |
|
|
res = i2c_add_driver(&i2cdev_driver);
|
| 586 |
|
|
if (res)
|
| 587 |
|
|
goto out_unreg_class;
|
| 588 |
|
|
|
| 589 |
|
|
return 0;
|
| 590 |
|
|
|
| 591 |
|
|
out_unreg_class:
|
| 592 |
|
|
class_destroy(i2c_dev_class);
|
| 593 |
|
|
out_unreg_chrdev:
|
| 594 |
|
|
unregister_chrdev(I2C_MAJOR, "i2c");
|
| 595 |
|
|
out:
|
| 596 |
|
|
printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
|
| 597 |
|
|
return res;
|
| 598 |
|
|
}
|
| 599 |
|
|
|
| 600 |
|
|
static void __exit i2c_dev_exit(void)
|
| 601 |
|
|
{
|
| 602 |
|
|
i2c_del_driver(&i2cdev_driver);
|
| 603 |
|
|
class_destroy(i2c_dev_class);
|
| 604 |
|
|
unregister_chrdev(I2C_MAJOR,"i2c");
|
| 605 |
|
|
}
|
| 606 |
|
|
|
| 607 |
|
|
MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
|
| 608 |
|
|
"Simon G. Vogl <simon@tk.uni-linz.ac.at>");
|
| 609 |
|
|
MODULE_DESCRIPTION("I2C /dev entries driver");
|
| 610 |
|
|
MODULE_LICENSE("GPL");
|
| 611 |
|
|
|
| 612 |
|
|
module_init(i2c_dev_init);
|
| 613 |
|
|
module_exit(i2c_dev_exit);
|
