Linux驱动开发之tiny6410_LED驱动

只看该作者 · 2011-11-24 20:54

#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/pci.h>
#include <mach/map.h>
#include <mach/regs-gpio.h>
#include <mach/gpio-bank-k.h>
#include "leds.h"
#define DEVICE_NAME "tiny6410_leds"
MODULE_LICENSE("GPL");
MODULE_AUTHOR("pang123hui");
static long sbc2440_leds_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
switch(cmd) {
      unsigned tmp;
/*
case 0:
case 1:
      if(arg > 4)
      {
         //非法参数
         return -EINVAL;
      }
      tmp = readl(S3C64XX_GPKDAT);
      tmp &= ~(1 << (3 + arg));
      tmp |= ((cmd) << (3 + arg));
      writel(tmp, S3C64XX_GPKDAT);
      return 0;
*/

case 1:
case 2:
case 3:
case 4:
      tmp = readl(S3C64XX_GPKDAT);
      tmp = (tmp & ~(1<<(cmd - 1 + 4)))|(arg<<(cmd -1 + 4));
      writel(tmp, S3C64XX_GPKDAT);
      return 0;

default:
      return -EINVAL;
}
}
static struct file_operations dev_fops = {
.owner       = THIS_MODULE,
.unlocked_ioctl = sbc2440_leds_ioctl,
};
//misc device：杂项设备，即主设备号为10的特殊字符设备
static struct miscdevice misc = {
//次设备号，注意不要与/proc/misc中已有杂项设备次设备号冲突
//MISC_DYNAMIC_MINOR来动态获取次设备号
.minor = MISC_DYNAMIC_MINOR,
//设备名称
.name = DEVICE_NAME,
.fops = &dev_fops,
};
static int __init dev_init(void)
{
int ret;
{
      unsigned tmp;
      tmp = readl(S3C64XX_GPKCON);
      //GPKCON配置GPK4到GPK7配置为0001输出
      tmp = (tmp & ~(0xffffU<<16))|(0x1111U<<16);
      writel(tmp, S3C64XX_GPKCON);

      //GPKDAT[7:4] = 1
      //灯灭
      tmp = readl(S3C64XX_GPKDAT);
      tmp |= (0xF << 4);
      writel(tmp, S3C64XX_GPKDAT);
      //禁止上拉下拉
      tmp = readl(S3C64XX_GPKPUD);
      tmp &= (0x00 << 8);
      writel(tmp, S3C64XX_GPKPUD);
}
//该函数会自动创建设备节点，即设备文件
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);
makefile
ifneq ($(KERNELRELEASE),)
obj-m := leds.o
else
KERNELDIR := /opt/FriendlyARM/mini6410/linux/linux-2.6.38
PWD:=$(shell pwd)
all:
make -C $(KERNELDIR) M=$(PWD) modules
clean:
rm -rf *.ko *.o *.mod.c *.mod.o *.symvers
endif
leds_test
#include <stdio.h>
//exit
#include <stdlib.h>
#include <sys/ioctl.h>
int main(int argc, char **argv)
{
int num = 0;
int led_state = 1;
int fd = 0;
//参数赋值
if(argc != 3 || sscanf(argv[1],"%d", &num) != 1 || sscanf(argv[2], "%d", &led_state) != 1 || num > 4 || led_state > 1)
{
      fprintf(stderr, "error\n");
      exit(1);
}
printf("num = %d, led_state = %d\n", num, led_state);
fd = open("/dev/tiny6410_leds", 0);
if (fd < 0) {
      fd = open("/dev/tiny6410_leds0", 0);
}
if (fd < 0) {
      perror("open device leds");
      exit(1);
}
ioctl(fd, num, led_state);
printf("led%d\n", num);
close(fd);
return 0;
}