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/*
* linux/drivers/char/ar7_gpio.c
*
* Copyright (C) 2007 OpenWrt.org
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/types.h>
#include <linux/cdev.h>
#include <gpio.h>
#define DRVNAME "ar7_gpio"
#define LONGNAME "TI AR7 GPIOs Driver"
MODULE_AUTHOR("Nicolas Thill <nico@openwrt.org>");
MODULE_DESCRIPTION(LONGNAME);
MODULE_LICENSE("GPL");
static int ar7_gpio_major = 0;
static ssize_t ar7_gpio_write(struct file *file, const char __user *buf,
size_t len, loff_t *ppos)
{
int pin = iminor(file->f_dentry->d_inode);
size_t i;
for (i = 0; i < len; ++i) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
switch (c) {
case '0':
gpio_set_value(pin, 0);
break;
case '1':
gpio_set_value(pin, 1);
break;
case 'd':
case 'D':
ar7_gpio_disable(pin);
break;
case 'e':
case 'E':
ar7_gpio_enable(pin);
break;
case 'i':
case 'I':
case '<':
gpio_direction_input(pin);
break;
case 'o':
case 'O':
case '>':
gpio_direction_output(pin);
break;
default:
return -EINVAL;
}
}
return len;
}
static ssize_t ar7_gpio_read(struct file *file, char __user * buf,
size_t len, loff_t * ppos)
{
int pin = iminor(file->f_dentry->d_inode);
int value;
value = gpio_get_value(pin);
if (put_user(value ? '1' : '0', buf))
return -EFAULT;
return 1;
}
static int ar7_gpio_open(struct inode *inode, struct file *file)
{
int m = iminor(inode);
if (m >= AR7_GPIO_MAX)
return -EINVAL;
return nonseekable_open(inode, file);
}
static int ar7_gpio_release(struct inode *inode, struct file *file)
{
return 0;
}
static const struct file_operations ar7_gpio_fops = {
.owner = THIS_MODULE,
.write = ar7_gpio_write,
.read = ar7_gpio_read,
.open = ar7_gpio_open,
.release = ar7_gpio_release,
.llseek = no_llseek,
};
static struct platform_device *ar7_gpio_device;
static int __init ar7_gpio_init(void)
{
int rc;
ar7_gpio_device = platform_device_alloc(DRVNAME, -1);
if (!ar7_gpio_device)
return -ENOMEM;
rc = platform_device_add(ar7_gpio_device);
if (rc < 0)
goto out_put;
rc = register_chrdev(ar7_gpio_major, DRVNAME, &ar7_gpio_fops);
if (rc < 0)
goto out_put;
ar7_gpio_major = rc;
goto out;
out_put:
platform_device_put(ar7_gpio_device);
out:
return rc;
}
static void __exit ar7_gpio_exit(void)
{
unregister_chrdev(ar7_gpio_major, DRVNAME);
platform_device_unregister(ar7_gpio_device);
}
module_init(ar7_gpio_init);
module_exit(ar7_gpio_exit);
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