leds

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/ioctl.h>
#include <linux/cdev.h>
#include <linux/delay.h>

#include <linux/gpio.h>
#include <mach/gpio.h>
#include <plat/gpio-cfg.h>

#define DEVICE_NAME "led9"

static int led_gpios[] = {
EXYNOS4X12_GPM4(0),
EXYNOS4X12_GPM4(1),
EXYNOS4X12_GPM4(2),
EXYNOS4X12_GPM4(3),
};

#define LED_NUM ARRAY_SIZE(led_gpios)

static long tiny4412_leds_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
switch(cmd) {
case 0:
case 1:
if (arg > LED_NUM) {
return -EINVAL;
}

gpio_set_value(led_gpios[arg], !cmd);
//printk(DEVICE_NAME": %d %d\n", arg, cmd);
break;

default:
return -EINVAL;
}

return 0;
}

static struct file_operations tiny4412_led_dev_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = tiny4412_leds_ioctl,
};

static struct miscdevice tiny4412_led_dev = {
.minor = MISC_DYNAMIC_MINOR,
.name = DEVICE_NAME,
.fops = &tiny4412_led_dev_fops,
};

static int __init tiny4412_led_dev_init(void) {
int ret;
int i;

for (i = 0; i < LED_NUM; i++) {
ret = gpio_request(led_gpios[i], "LED");
if (ret) {
printk("%s: request GPIO %d for LED failed, ret = %d\n", DEVICE_NAME,
led_gpios[i], ret);
return ret;
}

s3c_gpio_cfgpin(led_gpios[i], S3C_GPIO_OUTPUT);
gpio_set_value(led_gpios[i], 1);
}

ret = misc_register(&tiny4412_led_dev);

printk(DEVICE_NAME"\tinitialized\n");

return ret;
}

static void __exit tiny4412_led_dev_exit(void) {
int i;

for (i = 0; i < LED_NUM; i++) {
gpio_free(led_gpios[i]);
}

misc_deregister(&tiny4412_led_dev);
}

module_init(tiny4412_led_dev_init);
module_exit(tiny4412_led_dev_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("FriendlyARM Inc.");

 上层测试程序

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/ioctl.h>

int main(int argc,char *argv[])
{
int led_fd;
unsigned char ledflag = 0,num=0;

if(argc!=4)
{
printf("Usage:<%s> </dev/?node> <0/1> num\n",argv[0]);
return -1;
}

led_fd = open(argv[1],O_WRONLY);

ledflag = atoi(argv[2]);
num = atoi(argv[3]);
//write(led_fd, &ledflag,1);

ioctl(led_fd,ledflag,num);

}

 Makefile

obj-m += leddriver.o
SOURCE = ledtest.o

CROSS_COMPLIE = arm-linux-
CC = $(CROSS_COMPLIE)gcc

KERNDIR = /centos/xyd/linux-3.5
#CURDIR = $(shell pwd)
CURDIR = `pwd`

.PHONY: module clean

all: module $(SOURCE:.o=)

module:
$(MAKE) -C $(KERNDIR) M=$(CURDIR) modules

$(SOURCE:.o=):$(SOURCE)
$(CC) -o $@ $^

%.o:%.c
$(CC) -c $<

clean:
$(MAKE) -C $(KERNDIR) M=$(CURDIR) clean
rm $(SOURCE:.o=)

 仅供参考！！！！

tiny4412字符设备的上层测试程序（底层驱动为/dev/leds）