對mini2440LED燈驅動開發

一直在學習友善之臂的MINI2440開發板，今天完成了，led的實驗在此總結一下

1.編寫驅動程式（led1.c）

#include <linux/miscdevice.h>#include <linux/delay.h>#include <asm/irq.h>#include <mach/regs-gpio.h>#include <mach/hardware.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/init.h>#include <linux/mm.h>#include <linux/fs.h>#include <linux/types.h>#include <linux/delay.h>#include <linux/moduleparam.h>#include <linux/slab.h>#include <linux/errno.h>#include <linux/ioctl.h>#include <linux/cdev.h>#include <linux/string.h>#include <linux/list.h>#include <linux/pci.h>#include <linux/gpio.h>#include <asm/uaccess.h>#include <asm/atomic.h>#include <asm/unistd.h>#define DEVICE_NAME "leds"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 int sbc2440_leds_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg){switch(cmd) {case 0:case 1:if (arg > 4) {return -EINVAL;}s3c2410_gpio_setpin(led_table[arg], !cmd);return 0;default:return -EINVAL;}}static struct file_operations dev_fops = {.owner=THIS_MODULE,.ioctl=sbc2440_leds_ioctl,};static struct miscdevice misc = {.minor = MISC_DYNAMIC_MINOR,.name = DEVICE_NAME,.fops = &dev_fops,};static int __init dev_init(void){int ret;int i;for (i = 0; i < 4; i++) {s3c2410_gpio_cfgpin(led_table[i], led_cfg_table[i]);s3c2410_gpio_setpin(led_table[i], 0);}ret = misc_register(&misc);printk (DEVICE_NAME"\tinitialized\n");return ret;}static void __exit dev_exit(void){misc_deregister(&misc);}module_init(dev_init);module_exit(dev_exit);MODULE_LICENSE("GPL");MODULE_AUTHOR("FriendlyARM Inc.");

2.驅動程式makefile檔案

obj-m:=led1.oCURRENT_PATH:=$(shell pwd)ARM_LINUX_KERNEL:=/opt/FriendlyARM/mini2440/linux-2.6.32.2all: $(MAKE) -C $(ARM_LINUX_KERNEL) SUBDIRS=$(CURRENT_PATH) modulesclean: rm -rf *.cmd *.o *.ko  *.mod.c *.symvers *.order

3.測試程式

#include <stdio.h>#include <stdlib.h>#define LED_ON   1#define LED_OFF  0#define LED_DEVICE  "/dev/leds"int main(int argc,char **argv){int fd,led_num;fd = open(LED_DEVICE,0);if(fd < 0){printf("can't open /dev/leds!\n");exit(0);}            led_num = atoi(argv[1]);if(!(strcmp(argv[2],"on"))){ioctl(fd,LED_ON,led_num);}else if(!(strcmp(argv[2],"off"))){ioctl(fd,LED_OFF,led_num);}else{exit(0);}exit(0);}

4.測試程式的Makefile

all:      arm-linux-gcc led_app.c -o led_app   clean:       rm -rf *.o led_app

編譯驅動程式和測試程式，把得到的led1.ko和 led_app檔案通過ftp上傳到開發板並複製到的/home目錄下，在啟動指令碼裡面設定自動載入,就是在/etc/init.d/rcS裡面加了兩句：

echo “---------insmod led1.ko---------

insmod /home/led1.ko

注意：開發板預設的檔案系統已經有了led 測試程式，所以在開發板的命令列終端執行：

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

執行測試代碼：

./led_app  0 on //點亮LED1

./led_app  0 off //熄滅LED1

。。。。。。。。。