Driver for LED lamp control mounted to/sys

Mount a directory under/sys/power to control LED lights of the Development Board

1. driver source code

#include <linux/kobject.h>#include <linux/sysfs.h>#include <linux/init.h>#include <linux/kernel.h>#include <linux/platform_device.h>#include <linux/device.h>#include <linux/module.h>#include <asm/uaccess.h>#include <linux/gpio.h>#include <mach/regs-gpio.h>MODULE_LICENSE("Dual BSD/GPL");static unsigned long led_table [] = {S3C2410_GPB(5),S3C2410_GPB(6),S3C2410_GPB(7),S3C2410_GPB(8),};static unsigned int led_cfg_table[] ={     S3C2410_GPIO_OUTPUT, S3C2410_GPIO_OUTPUT,S3C2410_GPIO_OUTPUT,S3C2410_GPIO_OUTPUT,};static ssize_t leds_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t len){int status = 0,i;sscanf(buf, "%d", &status);for(i=0;i<4;i++){s3c2410_gpio_setpin(led_table[i],!status);}//Todo.printk("store1 stauts %d\n", status);return len;}static ssize_t leds_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf){int status = 0, len = 0;len += sprintf(buf + len, "%d\n",status);//Todo.printk("show1 stauts %d\n", status);return len;}static struct kobj_attribute leds_attr = {.attr= {.name = __stringify(leds),.mode = 0644,},.show = leds_show,.store = leds_store,};static struct attribute * extend_power_ctrl[] = {&leds_attr.attr,NULL,};static struct attribute_group attr_extend_ctrl_group = {.attrs = extend_power_ctrl,};static void extend_power_ctrl_default(){//Todo.//init gpio for leds, etc.}extern struct kobject *power_kobj;static int extend_power_ctrl_init(void){extend_power_ctrl_default();//power_kobj = sysfs_create_and_add("leds", NULL);if (sysfs_create_group(power_kobj, &attr_extend_ctrl_group)){printk("extend power interface init is failed!\n");return 1;}return 0;}static void extend_power_ctrl_exit(void){sysfs_remove_group(power_kobj, &attr_extend_ctrl_group);}static int __init obj_sys_init(void){int i;for( i=0;i<4;i++){s3c2410_gpio_cfgpin(led_table[i], led_cfg_table[i]);}int ret;printk("obj sys init!\n");ret = extend_power_ctrl_init();return ret;}static void obj_sys_exit(void){printk("obj sys exit!\n");extend_power_ctrl_exit();}module_init(obj_sys_init);module_exit(obj_sys_exit);

2. Load the kernel to compile and generate the zImage file, and then download it to the Development Board.

Execute echo 1>/sys/power/leds. The light is on.

Run echo 0>/sys/power/leds to turn off all lights

Note: The default file system of the Development Board already has an led test program. Therefore, run the following command on the command line terminal of the Development Board:

#/Etc/rc. d/init. d/leds stop