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/*
i2c-dev.c - i2c-bus driver, char device interface
Copyright (C) 1995-97 Simon G. Vogl
Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
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>
#ifdef MODULE
extern int init_module(void);
extern int cleanup_module(void);
#endif /* def MODULE */
/* 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);
#endif
static 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);
#ifdef MODULE
static
#else
extern
#endif
int __init i2c_dev_init(void);
static int 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_MAX
static struct i2c_adapter *i2cdev_adaps[I2CDEV_ADAPS_MAX];
#ifdef CONFIG_DEVFS_FS
static devfs_handle_t devfs_i2c[I2CDEV_ADAPS_MAX];
static devfs_handle_t devfs_handle = NULL;
#endif
static 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;
}
#endif
static 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;
}
int __init i2c_dev_init(void)
{
int res;
printk("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;
}
int 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 res;
}
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 res;
}
i2cdev_initialized --;
}
return 0;
}
EXPORT_NO_SYMBOLS;
#ifdef MODULE
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");
int init_module(void)
{
return i2c_dev_init();
}
int cleanup_module(void)
{
return i2cdev_cleanup();
}
#endif /* def MODULE */
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