驱动-按键-中断模式

驱动-按键-中断模式

eint_drv.c

/*******驱动代码************/#include <linux/module.h>#include <linux/kernel.h>#include <linux/fs.h>#include <linux/init.h>#include <linux/delay.h>#include <linux/irq.h>#include <asm/uaccess.h>#include <asm/irq.h>#include <asm/io.h>#include <asm/arch/regs-gpio.h>#include <asm/hardware.h>static struct class *eintdrv_class;static struct class_device*eintdrv_class_dev;volatile unsigned long *gpfcon;volatile unsigned long *gpfdat;volatile unsigned long *gpgcon;volatile unsigned long *gpgdat;/*声明等待队列头，名字为button_waitq*/static DECLARE_WAIT_QUEUE_HEAD(button_waitq);/* 中断事件标志, 中断服务程序将它置1，eint_drv_read将它清0 */static volatile int ev_press = 0;struct pin_desc{unsigned int pin;unsigned int key_val;};/* 键值: 按下时, 0x01, 0x02, 0x03, 0x04 *//* 键值: 松开时, 0x81, 0x82, 0x83, 0x84 */static unsigned char key_val;struct pin_desc pins_desc[4] = {{S3C2410_GPF0, 0x01},{S3C2410_GPF2, 0x02},{S3C2410_GPG3, 0x03},{S3C2410_GPG11, 0x04},};/*  * 确定按键值  */static irqreturn_t buttons_irq(int irq, void *dev_id){struct pin_desc * pindesc = (struct pin_desc *)dev_id;unsigned int pinval;pinval = s3c2410_gpio_getpin(pindesc->pin);if (pinval){/* 松开 */key_val = 0x80 | pindesc->key_val;printk("pinval1=%d\n", pinval);}else{/* 按下 */key_val = pindesc->key_val;printk("pinval2=%d\n", pinval);}  /* 表示中断发生了 */  ev_press=1;  /* 唤醒休眠的进程 */  wake_up_interruptible(&button_waitq);return IRQ_RETVAL(IRQ_HANDLED);}static int eint_drv_open(struct inode *inode, struct file *file){/* 配置GPF0,2为输入引脚 *///*gpfcon &= ~((3<<4)|(3<<0));*gpfcon &=~((1<<0)|(1<<2));/* 配置GPG3,11为输入引脚 *///*gpgcon &= ~((3<<6)|(3<<22));*gpgcon &= ~((1<<3)|(1<<11));/*request_irq(中断类型，响应函数，触发方式，名称，数据)*/ request_irq(IRQ_EINT0, buttons_irq, IRQT_BOTHEDGE, "S2", &pins_desc[0]);    request_irq(IRQ_EINT2, buttons_irq, IRQT_BOTHEDGE, "S3", &pins_desc[1]);    request_irq(IRQ_EINT11, buttons_irq, IRQT_BOTHEDGE, "S4", &pins_desc[2]);    request_irq(IRQ_EINT19, buttons_irq, IRQT_BOTHEDGE, "S5", &pins_desc[3]);     return 0;}ssize_t eint_drv_read(struct file *file, char __user *buf, size_t size, loff_t *ppos){if (size != 1)return -EINVAL;/* 如果没有按键动作, 休眠 */wait_event_interruptible(button_waitq,ev_press);/* 如果有按键动作, 返回键值 */copy_to_user(buf, &key_val, 1);ev_press = 0;return 1;}int eint_drv_close(struct inode *inode, struct file *file){/*free_irq*/free_irq(IRQ_EINT0,&pins_desc[0]);free_irq(IRQ_EINT2,&pins_desc[1]);free_irq(IRQ_EINT11,&pins_desc[2]);free_irq(IRQ_EINT19,&pins_desc[3]);return 0;}static struct file_operations sencod_drv_fops = {    .owner   =  THIS_MODULE,    /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */    .open    =  eint_drv_open,     .read =eint_drv_read,   .release =  eint_drv_close,   };int major;static int eint_drv_init(void){major = register_chrdev(0, "eint_drv", &sencod_drv_fops);eintdrv_class = class_create(THIS_MODULE, "eint_drv");eintdrv_class_dev = class_device_create(eintdrv_class, NULL, MKDEV(major, 0), NULL, "buttons"); /* /dev/buttons */gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);gpfdat = gpfcon + 1;gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16);gpgdat = gpgcon + 1;return 0;}static void eint_drv_exit(void){unregister_chrdev(major, "eint_drv");class_device_unregister(eintdrv_class_dev);class_destroy(eintdrv_class);iounmap(gpfcon);iounmap(gpgcon);return 0;}module_init(eint_drv_init);module_exit(eint_drv_exit);MODULE_LICENSE("GPL");

eintTest.c

#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <stdio.h>#include <unistd.h>/* thirddrvtest   */int main(int argc, char **argv){int fd;unsigned char key_val;fd = open("/dev/eintTest", O_RDWR);//O_RDWR 读、写打开。if (fd < 0){printf("can't open!\n");}while (1){read(fd, &key_val, 1);printf("key_val = 0x%x\n", key_val);sleep(5);}return 0;}

makefile

KERN_DIR = /work/system/linux-2.6.22.6all:make -C $(KERN_DIR) M=`pwd` modules clean:make -C $(KERN_DIR) M=`pwd` modules cleanrm -rf modules.orderobj-m+= eint_drv.o