/*    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>    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> *//* $Id: i2c-dev.c,v 1.40 2001/08/25 01:28:01 mds Exp $ */#include <linux/config.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/fs.h>#include <linux/slab.h>#include <linux/version.h>#if LINUX_KERNEL_VERSION >= KERNEL_VERSION(2,4,0)#include <linux/smp_lock.h>#endif /* LINUX_KERNEL_VERSION >= KERNEL_VERSION(2,4,0) */#ifdef CONFIG_DEVFS_FS#include <linux/devfs_fs_kernel.h>#endif/* If you want debugging uncomment: *//* #define DEBUG */#include <linux/init.h>#include <asm/uaccess.h>#include <linux/i2c.h>#include <linux/i2c-dev.h>/* struct file_operations changed too often in the 2.1 series for nice code */#if LINUX_KERNEL_VERSION < KERNEL_VERSION(2,4,9)static loff_t i2cdev_lseek (struct file *file, loff_t offset, int origin);#endifstatic ssize_t i2cdev_read (struct file *file, char *buf, size_t count,                             loff_t *offset);static ssize_t i2cdev_write (struct file *file, const char *buf, size_t count,                              loff_t *offset);static int i2cdev_ioctl (struct inode *inode, struct file *file,                          unsigned int cmd, unsigned long arg);static int i2cdev_open (struct inode *inode, struct file *file);static int i2cdev_release (struct inode *inode, struct file *file);static int i2cdev_attach_adapter(struct i2c_adapter *adap);static int i2cdev_detach_client(struct i2c_client *client);static int i2cdev_command(struct i2c_client *client, unsigned int cmd,                           void *arg);static int __init i2c_dev_init(void);static void i2cdev_cleanup(void);static struct file_operations i2cdev_fops = {#if LINUX_KERNEL_VERSION >= KERNEL_VERSION(2,4,0)	owner:		THIS_MODULE,#endif /* LINUX_KERNEL_VERSION >= KERNEL_VERSION(2,4,0) */#if LINUX_KERNEL_VERSION < KERNEL_VERSION(2,4,9)	llseek:		i2cdev_lseek,#else	llseek:		no_llseek,#endif	read:		i2cdev_read,	write:		i2cdev_write,	ioctl:		i2cdev_ioctl,	open:		i2cdev_open,	release:	i2cdev_release,};#define I2CDEV_ADAPS_MAX I2C_ADAP_MAXstatic struct i2c_adapter *i2cdev_adaps[I2CDEV_ADAPS_MAX];#ifdef CONFIG_DEVFS_FSstatic devfs_handle_t devfs_i2c[I2CDEV_ADAPS_MAX];static devfs_handle_t devfs_handle = NULL;#endifstatic struct i2c_driver i2cdev_driver = {	name:		"i2c-dev dummy driver",	id:		I2C_DRIVERID_I2CDEV,	flags:		I2C_DF_DUMMY,	attach_adapter:	i2cdev_attach_adapter,	detach_client:	i2cdev_detach_client,	command:	i2cdev_command,/*	inc_use:	NULL,	dec_use:	NULL, */};static struct i2c_client i2cdev_client_template = {	name:		"I2C /dev entry",	id:		1,	flags:		0,	addr:		-1,/*	adapter:	NULL, */	driver:		&i2cdev_driver,/*	data:		NULL */};static int i2cdev_initialized;#if LINUX_KERNEL_VERSION < KERNEL_VERSION(2,4,9)/* Note that the lseek function is called llseek in 2.1 kernels. But things   are complicated enough as is. */loff_t i2cdev_lseek (struct file *file, loff_t offset, int origin){#ifdef DEBUG	struct inode *inode = file->f_dentry->d_inode;	printk("i2c-dev.o: i2c-%d lseek to %ld bytes relative to %d.\n",	       MINOR(inode->i_rdev),(long) offset,origin);#endif /* DEBUG */	return -ESPIPE;}#endifstatic ssize_t i2cdev_read (struct file *file, char *buf, size_t count,                            loff_t *offset){	char *tmp;	int ret;#ifdef DEBUG	struct inode *inode = file->f_dentry->d_inode;#endif /* DEBUG */	struct i2c_client *client = (struct i2c_client *)file->private_data;	/* copy user space data to kernel space. */	tmp = kmalloc(count,GFP_KERNEL);	if (tmp==NULL)		return -ENOMEM;#ifdef DEBUG	printk("i2c-dev.o: i2c-%d reading %d bytes.\n",MINOR(inode->i_rdev),	       count);#endif	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 *buf, size_t count,                             loff_t *offset){	int ret;	char *tmp;	struct i2c_client *client = (struct i2c_client *)file->private_data;#ifdef DEBUG	struct inode *inode = file->f_dentry->d_inode;#endif /* DEBUG */	/* copy user space data to kernel space. */	tmp = kmalloc(count,GFP_KERNEL);	if (tmp==NULL)		return -ENOMEM;	if (copy_from_user(tmp,buf,count)) {		kfree(tmp);		return -EFAULT;	}#ifdef DEBUG	printk("i2c-dev.o: i2c-%d writing %d bytes.\n",MINOR(inode->i_rdev),	       count);#endif	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;	int i,datasize,res;	unsigned long funcs;#ifdef DEBUG	printk("i2c-dev.o: i2c-%d ioctl, cmd: 0x%x, arg: %lx.\n", 	       MINOR(inode->i_rdev),cmd, arg);#endif /* DEBUG */	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_FUNCS:		funcs = i2c_get_functionality(client->adapter);		return (copy_to_user((unsigned long *)arg,&funcs,		                     sizeof(unsigned long)))?-EFAULT:0;        case I2C_RDWR:		if (copy_from_user(&rdwr_arg, 				   (struct i2c_rdwr_ioctl_data *)arg, 				   sizeof(rdwr_arg)))			return -EFAULT;		rdwr_pa = (struct i2c_msg *)			kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), 			GFP_KERNEL);		if (rdwr_pa == NULL) return -ENOMEM;		res = 0;		for( i=0; i<rdwr_arg.nmsgs; i++ )		{		    	if(copy_from_user(&(rdwr_pa[i]),					&(rdwr_arg.msgs[i]),					sizeof(rdwr_pa[i])))			{			        res = -EFAULT;				break;			}			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,				rdwr_arg.msgs[i].buf,				rdwr_pa[i].len))			{			    	kfree(rdwr_pa[i].buf);			    	res = -EFAULT;				break;			}		}		if (!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(					rdwr_arg.msgs[i].buf,					rdwr_pa[i].buf,					rdwr_pa[i].len))				{					res = -EFAULT;				}			}			kfree(rdwr_pa[i].buf);		}		kfree(rdwr_pa);		return res;	case I2C_SMBUS:		if (copy_from_user(&data_arg,		                   (struct i2c_smbus_ioctl_data *) 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)) {#ifdef DEBUG			printk("i2c-dev.o: size out of range (%x) in ioctl I2C_SMBUS.\n",			       data_arg.size);#endif			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)) {#ifdef DEBUG			printk("i2c-dev.o: read_write out of range (%x) in ioctl I2C_SMBUS.\n",			       data_arg.read_write);#endif			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) {#ifdef DEBUG			printk("i2c-dev.o: data is NULL pointer in ioctl I2C_SMBUS.\n");#endif			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 == I2C_SMBUS_BLOCK_DATA */			datasize = sizeof(data_arg.data->block);		if ((data_arg.size == I2C_SMBUS_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.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;}int i2cdev_open (struct inode *inode, struct file *file){	unsigned int minor = MINOR(inode->i_rdev);	struct i2c_client *client;	if ((minor >= I2CDEV_ADAPS_MAX) || ! (i2cdev_adaps[minor])) {#ifdef DEBUG		printk("i2c-dev.o: Trying to open unattached adapter i2c-%d\n",		       minor);#endif		return -ENODEV;	}	/* Note that we here allocate a client for later use, but we will *not*	   register this client! Yes, this is safe. No, it is not very clean. */	if(! (client = kmalloc(sizeof(struct i2c_client),GFP_KERNEL)))		return -ENOMEM;	memcpy(client,&i2cdev_client_template,sizeof(struct i2c_client));	client->adapter = i2cdev_adaps[minor];	file->private_data = client;	if (i2cdev_adaps[minor]->inc_use)		i2cdev_adaps[minor]->inc_use(i2cdev_adaps[minor]);#if LINUX_KERNEL_VERSION < KERNEL_VERSION(2,4,0)	MOD_INC_USE_COUNT;#endif /* LINUX_KERNEL_VERSION < KERNEL_VERSION(2,4,0) */#ifdef DEBUG	printk("i2c-dev.o: opened i2c-%d\n",minor);#endif	return 0;}static int i2cdev_release (struct inode *inode, struct file *file){	unsigned int minor = MINOR(inode->i_rdev);	kfree(file->private_data);	file->private_data=NULL;#ifdef DEBUG	printk("i2c-dev.o: Closed: i2c-%d\n", minor);#endif#if LINUX_KERNEL_VERSION < KERNEL_VERSION(2,4,0)	MOD_DEC_USE_COUNT;#else /* LINUX_KERNEL_VERSION >= KERNEL_VERSION(2,4,0) */	lock_kernel();#endif /* LINUX_KERNEL_VERSION < KERNEL_VERSION(2,4,0) */	if (i2cdev_adaps[minor]->dec_use)		i2cdev_adaps[minor]->dec_use(i2cdev_adaps[minor]);#if LINUX_KERNEL_VERSION >= KERNEL_VERSION(2,4,0)	unlock_kernel();#endif /* LINUX_KERNEL_VERSION >= KERNEL_VERSION(2,4,0) */	return 0;}int i2cdev_attach_adapter(struct i2c_adapter *adap){	int i;	char name[8];	if ((i = i2c_adapter_id(adap)) < 0) {		printk("i2c-dev.o: Unknown adapter ?!?\n");		return -ENODEV;	}	if (i >= I2CDEV_ADAPS_MAX) {		printk("i2c-dev.o: Adapter number too large?!? (%d)\n",i);		return -ENODEV;	}	sprintf (name, "%d", i);	if (! i2cdev_adaps[i]) {		i2cdev_adaps[i] = adap;#ifdef CONFIG_DEVFS_FS		devfs_i2c[i] = devfs_register (devfs_handle, name,			DEVFS_FL_DEFAULT, I2C_MAJOR, i,			S_IFCHR | S_IRUSR | S_IWUSR,			&i2cdev_fops, NULL);#endif		printk("i2c-dev.o: Registered '%s' as minor %d\n",adap->name,i);	} else {		/* This is actually a detach_adapter call! */#ifdef CONFIG_DEVFS_FS		devfs_unregister(devfs_i2c[i]);#endif		i2cdev_adaps[i] = NULL;#ifdef DEBUG		printk("i2c-dev.o: Adapter unregistered: %s\n",adap->name);#endif	}	return 0;}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 int __init i2c_dev_init(void){	int res;	printk(KERN_DEBUG "i2c-dev.o: i2c /dev entries driver module\n");	i2cdev_initialized = 0;#ifdef CONFIG_DEVFS_FS	if (devfs_register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops)) {#else	if (register_chrdev(I2C_MAJOR,"i2c",&i2cdev_fops)) {#endif		printk("i2c-dev.o: unable to get major %d for i2c bus\n",		       I2C_MAJOR);		return -EIO;	}#ifdef CONFIG_DEVFS_FS	devfs_handle = devfs_mk_dir(NULL, "i2c", NULL);#endif	i2cdev_initialized ++;	if ((res = i2c_add_driver(&i2cdev_driver))) {		printk("i2c-dev.o: Driver registration failed, module not inserted.\n");		i2cdev_cleanup();		return res;	}	i2cdev_initialized ++;	return 0;}static void i2cdev_cleanup(void){	int res;	if (i2cdev_initialized >= 2) {		if ((res = i2c_del_driver(&i2cdev_driver))) {			printk("i2c-dev.o: Driver deregistration failed, "			       "module not removed.\n");			return;		}		i2cdev_initialized --;	}	if (i2cdev_initialized >= 1) {#ifdef CONFIG_DEVFS_FS		devfs_unregister(devfs_handle);		if ((res = devfs_unregister_chrdev(I2C_MAJOR, "i2c"))) {#else		if ((res = unregister_chrdev(I2C_MAJOR,"i2c"))) {#endif			printk("i2c-dev.o: unable to release major %d for i2c bus\n",			       I2C_MAJOR);			return;		}		i2cdev_initialized --;	}}EXPORT_NO_SYMBOLS;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(i2cdev_cleanup);