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159 lines
3.4 KiB
C
159 lines
3.4 KiB
C
/*
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* Copyright (C) 2007 Nicolas Thill <nico@openwrt.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <linux/device.h>
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#include <linux/fs.h>
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/uaccess.h>
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#include <linux/io.h>
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#include <linux/types.h>
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#include <linux/cdev.h>
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#include <gpio.h>
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#define DRVNAME "ar7_gpio"
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#define LONGNAME "TI AR7 GPIOs Driver"
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MODULE_AUTHOR("Nicolas Thill <nico@openwrt.org>");
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MODULE_DESCRIPTION(LONGNAME);
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MODULE_LICENSE("GPL");
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static int ar7_gpio_major;
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static ssize_t ar7_gpio_write(struct file *file, const char __user *buf,
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size_t len, loff_t *ppos)
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{
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int pin = iminor(file->f_path.dentry->d_inode);
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size_t i;
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for (i = 0; i < len; ++i) {
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char c;
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if (get_user(c, buf + i))
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return -EFAULT;
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switch (c) {
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case '0':
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gpio_set_value(pin, 0);
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break;
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case '1':
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gpio_set_value(pin, 1);
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break;
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case 'd':
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case 'D':
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ar7_gpio_disable(pin);
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break;
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case 'e':
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case 'E':
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ar7_gpio_enable(pin);
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break;
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case 'i':
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case 'I':
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case '<':
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gpio_direction_input(pin);
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break;
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case 'o':
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case 'O':
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case '>':
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gpio_direction_output(pin, 0);
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break;
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default:
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return -EINVAL;
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}
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}
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return len;
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}
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static ssize_t ar7_gpio_read(struct file *file, char __user *buf,
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size_t len, loff_t *ppos)
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{
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int pin = iminor(file->f_path.dentry->d_inode);
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int value;
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value = gpio_get_value(pin);
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if (put_user(value ? '1' : '0', buf))
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return -EFAULT;
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return 1;
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}
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static int ar7_gpio_open(struct inode *inode, struct file *file)
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{
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int m = iminor(inode);
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if (m >= (ar7_is_titan() ? TITAN_GPIO_MAX : AR7_GPIO_MAX))
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return -EINVAL;
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return nonseekable_open(inode, file);
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}
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static int ar7_gpio_release(struct inode *inode, struct file *file)
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{
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return 0;
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}
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static const struct file_operations ar7_gpio_fops = {
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.owner = THIS_MODULE,
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.write = ar7_gpio_write,
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.read = ar7_gpio_read,
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.open = ar7_gpio_open,
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.release = ar7_gpio_release,
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.llseek = no_llseek,
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};
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static struct platform_device *ar7_gpio_device;
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static int __init ar7_gpio_char_init(void)
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{
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int rc;
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ar7_gpio_device = platform_device_alloc(DRVNAME, -1);
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if (!ar7_gpio_device)
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return -ENOMEM;
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rc = platform_device_add(ar7_gpio_device);
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if (rc < 0)
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goto out_put;
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rc = register_chrdev(ar7_gpio_major, DRVNAME, &ar7_gpio_fops);
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if (rc < 0)
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goto out_put;
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ar7_gpio_major = rc;
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rc = 0;
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goto out;
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out_put:
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platform_device_put(ar7_gpio_device);
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out:
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return rc;
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}
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static void __exit ar7_gpio_char_exit(void)
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{
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unregister_chrdev(ar7_gpio_major, DRVNAME);
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platform_device_unregister(ar7_gpio_device);
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}
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module_init(ar7_gpio_char_init);
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module_exit(ar7_gpio_char_exit);
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