S3C2440 LED驱动

//头文件

#include
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#include

//定义设备名称
#define DEVICE_NAME "leds"

//led与ARM硬件连接

static unsigned long led_table [] = {
S3C2410_GPB(5),
S3C2410_GPB(6),
S3C2410_GPB(7),
S3C2410_GPB(8),
};

//ARM I/0配置为输出

static unsigned int led_cfg_table [] = {
S3C2410_GPIO_OUTPUT,
S3C2410_GPIO_OUTPUT,
S3C2410_GPIO_OUTPUT,
S3C2410_GPIO_OUTPUT,
};

//file operations 结构体的ioctl（）函数

static int ***c2440_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 = ***c2440_leds_ioctl,
};

static int __init dev_init(void)
{
int i,ret;
for (i = 0; i < 4; i++) {
  s3c2410_gpio_cfgpin(led_table, led_cfg_table);
  s3c2410_gpio_setpin(led_table, 0);
}

ret = misc_register(&misc);

printk (DEVICE_NAME"tInitializedn");

return ret;
}

static void __exit dev_exit(void)
{
misc_deregister(&misc);
}

module_init(dev_init);
module_exit(dev_exit);
MODULE_LICENSE("GPL");

/////////////////////////////////////////////////////////////////////////////////

//Makefile

DEVICE = led
ifneq ($(KERNELRELEASE),)
obj-m := ${DEVICE}.o
else
CC = arm-linux-gcc
KERNELDIR = /opt/linux-2.6.32.2
PWD       := $(shell pwd)
modules:
$(MAKE) -C $(KERNELDIR) M=$(PWD) LDDINC=$(KERNELDIR)/include modules

endif

clean:
rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions *.symvers *~ modules.order

depend .depend dep:
$(CC) $(CFLAGS) -M *.c > .depend

ifeq (.depend,$(wildcard .depend))
include .depend
endif

////////////////////////////////////////////////////////////////////////////////////////////

//API

#include
#include
#include
#include

int main(int argc, char **argv)
{
int on;
int led_no;
int fd;
if (argc != 3 || sscanf(argv[1], "%d", &led_no) != 1 || sscanf(argv[2],"%d", &on) != 1 ||
     on < 0 || on > 1 || led_no < 0 || led_no > 3) {
  fprintf(stderr, "Usage: leds led_no 0|1n");
  exit(1);
}
fd = open("/dev/leds0", 0);
if (fd < 0) {
  fd = open("/dev/leds", 0);
}
if (fd < 0) {
  perror("open device leds");
  exit(1);
}
ioctl(fd, on, led_no);
close(fd);
return 0;
}

////////////////////////////////////////////////////////////////

//Makefile

CROSS=arm-linux-

all: led

led: led.c
$(CROSS)gcc -o led led.c

clean:
@rm -vf led *.o *~