i2c-dev.c

s3c2410上面的I2C驱动程序,直接insmod就可以用了

/*
    i2c-dev.c - i2c-bus driver, char device interface  

    Copyright (C) 1995-97 Simon G. Vogl
    Copyright (C) 1998-99 Frodo Looijaard <[e-mail]>

    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 <[e-mail]> */

/* The devfs code is contributed by Philipp Matthias Hahn 
   <[e-mail]> */

/* $Id: i2c-dev.c,v 1.2 2004/02/06 13:19:45 laputa 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>


//laputa debug msg 030901
//#define LAPUTA_DEBUG_MSG	1
#include "dbg_msg.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);
#endif
//laputa unsigned char for iic data format 030903
//static ssize_t i2cdev_read (struct file *file, char *buf, size_t count,  // -- remove 
static ssize_t i2cdev_read (struct file *file, unsigned char *buf, size_t count,  // +- modify 
                            loff_t *offset);
//laputa unsigned char for iic data format 030903 
//static ssize_t i2cdev_write (struct file *file, const char *buf, size_t count, //--remove 
static ssize_t i2cdev_write (struct file *file, const unsigned char *buf, size_t count,  //+-modify
                             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_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

//laputa must be unsgined char type for the iic data 030903
//static ssize_t i2cdev_read (struct file *file, char *buf, size_t count,
static ssize_t i2cdev_read (struct file *file, unsigned char *buf, size_t count,
                            loff_t *offset)
{
	//char *tmp;     	// laputa -- remove
	unsigned char *tmp; // laputa +- modify 030903
	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

	DbgMsg(LAPUTA_DEBUG_MSG,printk("--> reading %d bytes.\n",count));
	
	ret = i2c_master_recv(client,tmp,count);
	if (ret >= 0)
		ret = copy_to_user(buf,tmp,count)?-EFAULT:ret;
	kfree(tmp);
	return ret;
}

//laputa must be unsgined char type for the iic data 030903
//static ssize_t i2cdev_write (struct file *file, const char *buf, size_t count,
static ssize_t i2cdev_write (struct file *file, const unsigned char *buf, size_t count,
                             loff_t *offset)
{
	int ret;
	// char *tmp; 			//--remove 
	unsigned char *tmp;     // +- modify 030903 
	struct i2c_client *client = (struct i2c_client *)file->private_data;

#ifdef DEBUG
	struct inode *inode = file->f_dentry->d_inode;
#endif /* DEBUG */

	//laputa check for buf chip addres setting & transfer data 030901
	DbgMsg(LAPUTA_DEBUG_MSG,printk("==>i2c dev  write buf [%s] addr[%x] \n",buf,client->addr));

	/* 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 */

	//laputa check for argument at ioctl 030830
	DbgMsg(LAPUTA_DEBUG_MSG,printk("client->name:%s:arg=%x\n",client->name,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;

	//laputa for to checked a address setting value 030830
	DbgMsg(LAPUTA_DEBUG_MSG,printk("==>I2C_SLAVE_FORCE ADD [%x]\n",client->addr));
		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;

		//laputa test only return value checked 030830
		DbgMsg(LAPUTA_DEBUG_MSG,printk("+++> receive data %s\n",rdwr_arg.msgs->buf));

		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,