字符设备驱动-模板
iorw.c
1 #include <linux/module.h> 2 #include <linux/init.h> 3 #include <linux/cdev.h> 4 #include <linux/fs.h> 5 #include <linux/io.h> 6 #include <mach/gpio-bank-k.h> 7 #include "led.h" 8 9 #define LEDCON 0x7f008800 10 #define LEDDAT 0x7f008808 11 unsigned int *led_config; 12 unsigned int *led_data; 13 14 struct cdev cdev; 15 dev_t devno; 16 17 int led_open(struct inode *node, struct file *filp) 18 { 19 led_config = ioremap(LEDCON,4); 20 writel(0x11110000,led_config); 21 22 led_data = ioremap(LEDDAT,4); 23 24 return 0; 25 } 26 27 long led_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 28 { 29 switch (cmd) 30 { 31 case LED_ON: 32 writel(0x00,led_data); 33 return 0; 34 35 case LED_OFF: 36 writel(0xff,led_data); 37 return 0; 38 39 default: 40 return -EINVAL; 41 } 42 } 43 44 static struct file_operations led_fops = 45 { 46 .open = led_open, 47 .unlocked_ioctl = led_ioctl, 48 }; 49 50 static int led_init() 51 { 52 cdev_init(&cdev,&led_fops); 53 54 alloc_chrdev_region(&devno, 0 , 1 , "myled"); 55 cdev_add(&cdev, devno, 1); 56 57 return 0; 58 } 59 60 static void led_exit() 61 { 62 cdev_del(&cdev); 63 unregister_chrdev_region(devno,1); 64 } 65 66 67 module_init(led_init); 68 module_exit(led_exit);
Makefile
obj-m := iorw.o KDIR := /home/arm/Desktop/share/资料/OK6818-C/源码/kernel-3.4.39 all: make -C $(KDIR) M=$(PWD) modules CROSS_COMPILE=arm-cortex_a9-linux-gnueabi- ARCH=arm clean: rm -f *.o *.ko *.order *.symvers
编译
make
