字符驱动程序框架与应用测试程序编写-源码

#include <linux/module.h> #include <linux/kernel.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/delay.h> #include <asm/uaccess.h> #include <asm/irq.h> #include <asm/io.h> #include <asm/arch/regs-gpio.h> #include <asm/hardware.h> typedef unsigned long Uint32; //寄存器定义 volatile unsigned long *gpiog_con=NULL; volatile unsigned long *gpiog_data=NULL; volatile unsigned long *gpiof_con=NULL; volatile unsigned long *gpiof_data=NULL; int major; static struct class* drv_keyled_class; static struct class_device* drv_keyled_class_device; /***驱动关键函数实现****/ /* 函数名：drv_keyled_open 功能：配置引脚功能 */ int drv_keyled_open(struct inode *inode, struct file *file) { char key_dat=1; printk("drv_keyled_open2\n"); //GPF4.5.6 *gpiof_con |= (1<<2*4) | (1<<2*5) | (1<<2*6) ; //输出 led *gpiof_data &= ((~(1<<4)) & (~(1<<5)) & (~(0<<6))); //2个亮 //GPG3,GPP0,GPP2 *gpiog_con |= (0x3<<2*11) ; //输入 key ((0x3<<2*3)) | return 0; } /* 函数名：drv_keyled_write 功能：控制led亮灭，实现反转 */ static ssize_t drv_keyled_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos) { unsigned char key_data[2]={1,1};; Uint32 data=*gpiof_data; //测试：读取用户传入的按键值 copy_from_user(key_data, buf, count); printk("kernel:the key is:%d , %d\n",key_data[0] ,key_data[1] ); //检验用户空间传输的按键值 //反转led *gpiof_data |= (1<<4) | (1<<5) |(1<<6); *gpiof_data &= ~(data & ((1<<4) | (1<<5) |(1<<6))); //反转指定位电平同时其他的不影响 return 0; } /* 函数名：drv_keyled_read 功能：读key电平 */ static ssize_t drv_keyled_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) { unsigned char key_data[2]={1,1}; unsigned char keybuf=0; if(size != sizeof(key_data))//用户空间（应用程序）要读取的字节与内核空间存的字节数一致 { printk("err:size"); return -EINVAL; } //把读取的按键值发给用户空间（应用端） key_data[0] = (*gpiof_data & (1<<0)) ? 1 : 0; key_data[1] = (*gpiog_data & (1<<3)) ? 1 : 0; if( key_data[0] == 0) { printk("key1 press \n"); while(!keybuf)//按下弹出 { keybuf= (*gpiof_data & (1<<0)) ? 1 : 0; } } if( key_data[1] == 0) { printk("key2 press \n"); while(!keybuf)//按下弹出 { keybuf= (*gpiog_data & (1<<3)) ? 1 : 0; } } copy_to_user(buf, key_data, sizeof(key_data));//copy_to_user(用户空间，内核空间，字节数) return sizeof(key_data); } //关键函数绑定 static struct file_operations drv_key_fops= { .owner = THIS_MODULE, .write = drv_keyled_write, .read = drv_keyled_read, .open = drv_keyled_open, }; /* 函数名：drv_keyled_init 功能：初始化模块功能（insmod装载时调用） */ static int drv_keyled_init(void) { //注册主设备号，由fops结构体告诉内核绑定的函数 major = register_chrdev(0, "drv_keyled", &drv_key_fops); //创建类 drv_keyled_class = class_create(THIS_MODULE, "drv_keyled"); //创建类设备 drv_keyled_class_device = class_device_create(drv_keyled_class, NULL, MKDEV(major, 0), NULL, "keyled");// "/dev/keyled" //虚拟地址VA映射 gpiof_con = (unsigned long*)ioremap(0x56000050, 12); //映射物理地址的起始地址与长度,返回虚拟地址 gpiof_data = gpiof_con+1;//地址在类型长度上加1（即+4地址） gpiog_con = (unsigned long*)ioremap(0x56000060, 12); //映射物理地址的起始地址与长度,返回虚拟地址 gpiog_data = gpiog_con+1; return 0; } /* 函数名：drv_keyled_exit 功能：卸载模块功能（rmmod卸载时调用） */ static void drv_keyled_exit(void) { unregister_chrdev(major, "drv_keyled"); class_device_unregister(drv_keyled_class_device); class_destroy(drv_keyled_class); iounmap(gpiof_con); iounmap(gpiog_con); } /**绑定驱动中关键实现函数**/ //初始化、卸载函数绑定(宏) module_init(drv_keyled_init); module_exit(drv_keyled_exit); //其他,声明驱动 MODULE_LICENSE("GPL");