学步园

一直在学习友善之臂的MINI2440开发板，今天完成了，led的实验在此总结一下

1.编写驱动程序（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.驱动程序makefile文件

obj-m:=led1.o

CURRENT_PATH:=$(shell pwd)

ARM_LINUX_KERNEL:=/opt/FriendlyARM/mini2440/linux-2.6.32.2

all:
	 $(MAKE) -C $(ARM_LINUX_KERNEL) SUBDIRS=$(CURRENT_PATH) modules

clean:
	 rm -rf *.cmd *.o *.ko  *.mod.c *.symvers *.order

3.测试程序

#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.测试程序的Makefile

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

编译驱动程序和测试程序，把得到的led1.ko和 led_app文件通过ftp上传到开发板并复制到的/home目录下，在启动脚本里面设置自动加载,就是在/etc/init.d/rcS里面加了两句：

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

insmod /home/led1.ko

注意：开发板缺省的文件系统已经有了led 测试程序，所以在开发板的命令行终端执行：

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

执行测试代码：

./led_app  0 on //点亮LED1

./led_app  0 off //熄灭LED1

。。。。。。。。。