2 * character device wrapper for generic gpio layer
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA02111-1307USA
18 * Feedback, Bugs... blogic@openwrt.org
22 #include <linux/module.h>
23 #include <linux/errno.h>
24 #include <linux/init.h>
25 #include <asm/uaccess.h>
28 #include <linux/init.h>
29 #include <linux/genhd.h>
30 #include <linux/device.h>
31 #include <linux/platform_device.h>
32 #include <linux/gpio_dev.h>
34 #define DRVNAME "gpiodev"
35 #define DEVNAME "gpio"
38 static int gpio_is_open = 0;
39 unsigned int gpio_access_mask = 0;
40 static struct class *gpio_class;
43 gpio_ioctl(struct inode * inode, struct file * file, unsigned int cmd, unsigned long arg)
47 if ((arg & gpio_access_mask) != arg)
56 retval = gpio_get_value(arg);
60 gpio_set_value(arg, 0);
64 gpio_set_value(arg, 0);
68 gpio_direction_input(arg);
72 gpio_direction_output(arg, 0);
85 gpio_open(struct inode *inode, struct file *file)
88 unsigned int dev_minor = MINOR(inode->i_rdev);
92 printk(KERN_ERR DRVNAME ": trying to access unknown minor device -> %d\n", dev_minor);
99 printk(KERN_ERR DRVNAME ": Device with minor ID %d already in use\n", dev_minor);
111 gpio_close(struct inode * inode, struct file * file)
118 struct file_operations gpio_fops = {
125 gpio_probe(struct platform_device *dev)
129 dev_major = register_chrdev(0, DEVNAME, &gpio_fops);
132 printk(KERN_ERR DRVNAME ": Error whilst opening %s \n", DEVNAME);
137 gpio_class = class_create(THIS_MODULE, DEVNAME);
138 class_device_create(gpio_class, NULL, MKDEV(dev_major, 0), NULL, DEVNAME);
140 printk(KERN_INFO DRVNAME ": gpio device registered with major %d\n", dev_major);
142 if (dev->num_resources != 1)
144 printk(KERN_ERR DRVNAME ": device may only have 1 resource\n");
149 gpio_access_mask = dev->resource[0].start;
151 printk(KERN_INFO DRVNAME ": gpio platform device registered with access mask %08X\n", gpio_access_mask);
157 gpio_remove(struct platform_device *dev)
159 unregister_chrdev(dev_major, DEVNAME);
164 platform_driver gpio_driver = {
166 .remove = gpio_remove,
169 .owner = THIS_MODULE,
176 int ret = platform_driver_register(&gpio_driver);
178 printk(KERN_INFO DRVNAME ": Error registering platfom driver!");
186 platform_driver_unregister(&gpio_driver);
189 module_init (gpio_mod_init);
190 module_exit (gpio_mod_exit);
192 MODULE_LICENSE("GPL");
193 MODULE_AUTHOR("John Crispin / OpenWrt");
194 MODULE_DESCRIPTION("Character device for for generic gpio api");