/*    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/config.h>#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	256static struct i2c_dev *i2c_dev_array[I2C_MINORS];static spinlock_t i2c_dev_array_lock = SPIN_LOCK_UNLOCKED;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;}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_dev(struct class_device *class_dev, char *buf){	struct i2c_dev *i2c_dev = to_i2c_dev(class_dev);	return print_dev_t(buf, MKDEV(I2C_MAJOR, i2c_dev->minor));}static CLASS_DEVICE_ATTR(dev, S_IRUGO, show_dev, NULL);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;}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 arbritrary 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;	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_dev);	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",	.id		= 1,	.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", __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);