微机实验报告(含思考题)实验5.doc

实验五 程序会提示：“please enter the led status” 输入与希望显示的led状态对应的ledstatus值（输入十进制值即可），观察led的显示情况。 例如： ? 输入数字“3”，对应的二进制数字为00000011 故点亮LED2LED7 ? 输入数字“4”，对应的二进制数字为00000100 故点亮LED0,LED1,LED3LED7 C语言程序： #include #include #include #include #include #include #include #include #include #include #include #include #include #define DEVICE_NAME s3c2440-led static int LedMajor=231; static int LedMinor=0; static char ledstatus=0xff; static struct class *s3c2440_class; static struct cdev * s3c2440_led_cdev; /* * * Function name: Update_led() * Descriptions : update the led status * Input : NONE * Output : NONE * */ static void Update_led(void) if(ledstatus&0x01) s3c2410_gpio_setpin(S3C2410_GPC7,1); /LED0灭 else s3c2410_gpio_setpin(S3C2410_GPC7,0); /LED0亮 if(ledstatus&0x02) s3c2410_gpio_setpin(S3C2410_GPC5,1); /LED1灭 else s3c2410_gpio_setpin(S3C2410_GPC5,0); /LED1亮 if(ledstatus&0x04) s3c2410_gpio_setpin(S3C2410_GPH9,1); /LED2灭 else s3c2410_gpio_setpin(S3C2410_GPH9,0); /LED2亮 if(ledstatus&0x08) s3c2410_gpio_setpin(S3C2410_GPB4,1); /LED3灭 else s3c2410_gpio_setpin(S3C2410_GPB4,0); /LED3亮 if(ledstatus&0x10) s3c2410_gpio_setpin(S3C2410_GPG5,1); /LED4灭 else s3c2410_gpio_setpin(S3C2410_GPG5,0); /LED4亮 if(ledstatus&0x20) s3c2410_gpio_setpin(S3C2410_GPG6,1); /LED5灭 else s3c2410_gpio_setpin(S3C2410_GPG6,0); /LED5亮 if(ledstatus&0x40) s3c2410_gpio_setpin(S3C2410_GPG7,1); /LED6灭 else s3c2410_gpio_setpin(S3C2410_GPG7,0); /LED6亮 if(ledstatus&0x80) s3c2410_gpio_setpin(S3C2410_GPG8,1); /LED7灭 else s3c2410_gpio_setpin(S3C2410_GPG8,0); /LED7亮 static ssize_t s3c2440_Led_write(struct file *file,const char *buffer,size_t count,loff_t *ppos) copy_from_user(&ledstatus,buffer,sizeof(ledstatus); Update_led(); printk(write: led=0x%x,count=%dn,ledstatus,count); return sizeof(ledstatus); static int s3c2440_Led_open(struct inode *inode,struct file *filp) printk(led device openn); return 0; static int s3c2440_Led_release(struct inode *inode,struct file *filp) printk(led device releasen); return 0; static struct file_operations s3c2440_fops= .owner=THIS_MODULE, .open=s3c2440_Led_open, .write=s3c2440_Led_write, .release=s3c2440_Led_release, ; static int _init s3c2440_Led_init(void) int ret; dev_t s3c2440_leds_devno; /*configure the gpio for leds*/ s3c2410_gpio_cfgpin(S3C2410_GPG5,S3C2410_GPIO_OUTPUT); s3c2410_gpio_cfgpin(S3C2410_GPG6,S3C2410_GPIO_OUTPUT); s3c2410_gpio_cfgpin(S3C2410_GPG7,S3C2410_GPIO_OUTPUT); s3c2410_gpio_cfgpin(S3C2410_GPG8,S3C2410_GPIO_OUTPUT); s3c2410_gpio_cfgpin(S3C2410_GPC7,S3C2410_GPIO_OUTPUT); s3c2410_gpio_cfgpin(S3C2410_GPC5,S3C2410_GPIO_OUTPUT); s3c2410_gpio_cfgpin(S3C2410_GPH9,S3C2410_GPIO_OUTPUT); s3c2410_gpio_cfgpin(S3C2410_GPB4,S3C2410_GPIO_OUTPUT); Update_led(); /*register the dev number*/ s3c2440_leds_devno= MKDEV (LedMajor, LedMinor); ret = register_chrdev_region (s3c2440_leds_devno, 1, DEVICE_NAME); /*register the char device*/ s3c2440_led_cdev = cdev_alloc(); if (s3c2440_led_cdev != NULL) cdev_init (s3c2440_led_cdev, &s3c2440_fops); s3c2440_led_cdev-owner = THIS_MODULE; if (cdev_add (s3c2440_led_cdev, s3c2440_leds_devno, 1) ) printk (KERN_NOTICE Something wrong when adding s3c2440_led_cdev!n); else printk (Success adding s3c2440_led_cdev!n); /*create the device node in /dev*/ s3c2440_class = class_create(THIS_MODULE, led_class); class_device_create(s3c2440_class, NULL, s3c2440_leds_devno, NULL, DEVICE_NAME); printk(DEVICE_NAME initializedn); return 0; static void _exit s3c2440_Led_exit(void) cdev_del(s3c2440_led_cdev); class_device_destroy(s3c2440_class, MKDEV(LedMajor, LedMinor); class_destroy(s3c2440_class); printk(DEVICE_NAME removedn); module_init(s3c2440_Led_init); module_exit(s3c2440_Led_exit); 1. 设备驱动程序的功能是什么？ 答：设备驱动的功能就是将系统提供的调用映射到作用于实际硬件的和设备相关的操作上。 2. 模块化的最大优