Android 驱动编写LED-NDK程序

#include <linux/kernel.h>#include <linux/module.h>#include <linux/fs.h>#include <linux/slab.h>#include <linux/device.h>#include <asm/io.h>#include <asm/uaccess.h>#include <linux/cdev.h>MODULE_LICENSE("GPL");#define GPM4CON 0X110002E0#define GPM4DAT 0X110002E4#define LED_ON _IOW(‘G‘,0,int)#define LED_OFF _IOW(‘G‘,1,int)static struct cdev dev;//1.1 分配cdev结构static dev_t dev_no;struct class *led_class;static unsigned int *led_con;static unsigned int *led_dat;long led_ioctl( struct file *file, unsigned int cmd, unsigned long arg ){  switch( cmd )  {    case LED_ON:      writel((readl(led_dat)&(~(0x1<<(arg-1)))),led_dat);      break;    case LED_OFF:      writel( (readl(led_dat)|(0x1<<(arg-1))),led_dat);      break;    default:       return -EINVAL;          break;  }  return 0;}struct file_operations led_fops = {  .owner = THIS_MODULE,  .unlocked_ioctl = led_ioctl,};static void hw_init(){    //初始化GPIO控制寄存器  led_con = ioremap( GPM4CON, 4 );  //地址映射  led_dat = ioremap( GPM4DAT, 4 );  writel((readl(led_con)&~0xffff)|0x1111,led_con);    writel(readl(led_dat)|0xf,led_dat);    }static int led_init(){    //1.2 初始化cdev结构  alloc_chrdev_region( &dev_no, 0, 1, "my_led" );  cdev_init( &dev, &led_fops );    dev.owner = THIS_MODULE;  //1.3 注册cdev结构  cdev_add( &dev, dev_no, 1 );  //2.硬件初始化  hw_init();  //3.创建设备文件  led_class = class_create(THIS_MODULE,"my_led");        //创建设备类  device_create( led_class, NULL, dev_no,NULL,"%s","my_led");  printk("init led device ok!/n");  return 0;}void led_exit(){  device_destroy(led_class,dev_no);  class_destroy(led_class);  iounmap(led_con);  iounmap(led_dat);  cdev_del(&dev);  unregister_chrdev_region(dev_no,1);}module_init( led_init );module_exit( led_exit );

LOCAL_PATH := $(call my-dir)include $(CLEAR_VARS)LOCAL_MODULE := ndk_test_myledLOCAL_SRC_FILES := ndk_led.cinclude $(BUILD_SHARED_LIBRARY)