diff options
Diffstat (limited to 'target/linux/ar7/files/drivers/char')
| -rw-r--r-- | target/linux/ar7/files/drivers/char/ar7_gpio.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/target/linux/ar7/files/drivers/char/ar7_gpio.c b/target/linux/ar7/files/drivers/char/ar7_gpio.c new file mode 100644 index 000000000..a7d0a5534 --- /dev/null +++ b/target/linux/ar7/files/drivers/char/ar7_gpio.c @@ -0,0 +1,158 @@ +/* + * Copyright (C) 2007 Nicolas Thill <nico@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 <linux/uaccess.h> +#include <linux/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; + +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, 0); + 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_is_titan() ? TITAN_GPIO_MAX : 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_char_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; + + rc = 0; + + goto out; + +out_put: + platform_device_put(ar7_gpio_device); +out: + return rc; +} + +static void __exit ar7_gpio_char_exit(void) +{ + unregister_chrdev(ar7_gpio_major, DRVNAME); + platform_device_unregister(ar7_gpio_device); +} + +module_init(ar7_gpio_char_init); +module_exit(ar7_gpio_char_exit); |