Gpio control driver

/* * Control LED for G7 project * * module name: gpio_led * * Author:sunsea * */#include <linux/kernel.h>#include <linux/module.h>#include <linux/device.h>#include <linux/fs.h>#include "../../../arch/arm/mach-tegra/gpio-names.h"#include <linux/gpio.h>#define DRIVER_VERSION"v1.0"#define DRIVER_AUTHOR"sunsea1026@gmail.com"#define DRIVER_DESC"led gpio control"#define DRIVER_LICENSE"GPL"#define DEV_NAME"gpio_led_control"static int gpio_led_major;static struct class *gpio_led_class;static struct device *gpio_led_dev;static int gpio_led_open(struct inode *inode, struct file *file){return 0;}static ssize_t gpio_led_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos){char cmd[64];char led_name[10] = {0};char led_state[10] = {0};int i = 0, j = 0;memset(cmd, 0x0, strlen(cmd));memcpy(cmd, buf, count);printk(KERN_INFO "cmd: %s\n", cmd);while (cmd[i] != '-') {led_name[i] = cmd[i];i++;}i++;while (cmd[i] != '\0')led_state[j++] = cmd[i++];if (!strcmp("red", led_name)) {if (!strcmp("on", led_state))gpio_set_value(TEGRA_GPIO_PS4, 1);elsegpio_set_value(TEGRA_GPIO_PS4, 0);}if (!strcmp("green", led_name)) {if (!strcmp("on", led_state))gpio_set_value(TEGRA_GPIO_PS5, 1);elsegpio_set_value(TEGRA_GPIO_PS5, 0);}if (!strcmp("blue", led_name)) {if (!strcmp("on", led_state))gpio_set_value(TEGRA_GPIO_PS6, 1);elsegpio_set_value(TEGRA_GPIO_PS6, 0);}return 0;}static ssize_t gpio_led_read(struct file *file, char __user *buf, size_t count,loff_t *ppos){return 0;}static ssize_t gpio_led_release(struct inode *inode, struct file *file){return 0;}static struct file_operations gpio_led_fops = {.owner= THIS_MODULE,.open= gpio_led_open,.write= gpio_led_write,.read= gpio_led_read,.release= gpio_led_release,};static int __init gpio_led_init(void){int error;gpio_led_major = register_chrdev(0, DEV_NAME, &gpio_led_fops);if (gpio_led_major < 0) {printk(KERN_ERR "%s:register gpio_led_control failed\n", __FILE__);goto out_unreg_chrdev;}gpio_led_class = class_create(THIS_MODULE, "gpio_led_control");if (IS_ERR(gpio_led_class)) {printk(KERN_ERR "%s:class create failed\n", __FILE__);goto out_unreg_class;}gpio_led_dev = device_create(gpio_led_class, NULL, MKDEV(gpio_led_major, 0), NULL, "gpio_led_control");if (IS_ERR(gpio_led_dev)) {printk(KERN_ERR "%s:device create failed\n", __FILE__);goto out_unreg_device;}printk(KERN_INFO "gpio_led_control load successfully.\n");return 0;out_unreg_device:error = PTR_ERR(gpio_led_dev);device_destroy(gpio_led_class, MKDEV(gpio_led_major, 0));class_destroy(gpio_led_class);unregister_chrdev(gpio_led_major, DEV_NAME);return error;out_unreg_class:error = PTR_ERR(gpio_led_class);class_destroy(gpio_led_class);unregister_chrdev(gpio_led_major, DEV_NAME);return error;out_unreg_chrdev:unregister_chrdev(gpio_led_major, DEV_NAME);return gpio_led_major;}static void __exit gpio_led_exit(void){device_destroy(gpio_led_class, MKDEV(gpio_led_major, 0));class_destroy(gpio_led_class);unregister_chrdev(gpio_led_major, DEV_NAME);printk(KERN_INFO "gpio_led_control unload successfully.\n");}module_init(gpio_led_init);module_exit(gpio_led_exit);MODULE_AUTHOR(DRIVER_AUTHOR);MODULE_DESCRIPTION(DRIVER_DESC);MODULE_LICENSE(DRIVER_LICENSE);