飞凌 ok6410 按键驱动源码及测试代码
由于OK6410的GPIO按键中断已经被飞凌自带的按键驱动注册，所以运行我们编写的按键驱动前要先去掉飞凌自带的按键驱动，方法：make menuconfig->Device Drivers->input device support->Key Boards->GPIO Buttons 去掉前面的*，即不选该项即可。
key.c
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/gpio.h>
#include <linux/types.h>
#include <linux/cdev.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/poll.h>
#include <linux/semaphore.h>
#include <linux/timer.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
//#include <mach/hardware.h>
#include <mach/irqs.h>
#define DEVICE_NAME "keyint"
#define KEYNUM 6
dev_t devid;
//static DEFINE_SEMAPHORE(key_lock); //declare a mutex lock for keyint
//定义一个信号量
struct semaphore key_lock;
static struct fasync_struct *key_async;
static struct timer_list key_timer;
struct key_irq_desc {
int irq; //irq num
unsigned long flags; //irq flags,identified the way of irq here,eq.edge,level
char *name; //irq name
};
static struct key_irq_desc key_irqs[] = {
//下降沿产生中断
{IRQ_EINT(0), IRQF_TRIGGER_FALLING, "KEY1"},
{IRQ_EINT(1), IRQF_TRIGGER_FALLING, "KEY2"},
{IRQ_EINT(2), IRQF_TRIGGER_FALLING, "KEY3"},
{IRQ_EINT(3), IRQF_TRIGGER_FALLING, "KEY4"},
{IRQ_EINT(4), IRQF_TRIGGER_FALLING, "KEY5"},
{IRQ_EINT(5), IRQF_TRIGGER_FALLING, "KEY6"},
};
/*define a waiting queue here*/
static DECLARE_WAIT_QUEUE_HEAD(key_waitq);
/*define a event flag ev_press*/
static volatile int ev_press = 0;
static volatile int press_cnt[KEYNUM] = {0,0,0,0,0,0};
/*中断处理函数*/
static irqreturn_t keys_interrupt(int irq, void *dev_id)
{
volatile int *press_cnt = (volatile int *) dev_id;
/*set the pressed key flag(must do here due to not be static value)*/
*press_cnt = *press_cnt + 1;
//延时10ms后执行定时器处理函数
mod_timer(&key_timer,jiffies+HZ/100); //start timer after 10ms
return IRQ_RETVAL(IRQ_HANDLED);
}
//定时器处理函数
static void key_timer_func(unsigned long data)
{
ev_press = 1;
//唤醒等待队列
wake_up_interruptible(&key_waitq);
kill_fasync(&key_async, SIGIO, POLL_IN);
}
static int key_fasync(int fd, struct file *filp, int on)
{
printk("Function key_fasync\n");
return fasync_helper(fd,filp,on,&key_async);
}
static unsigned key_poll(struct file *file, poll_table *wait)
{
unsigned int mask=0;
//指明要使用的等待队列
poll_wait(file,&key_waitq,wait);
//返回掩码
if(ev_press)
mask |= POLL_IN | POLLRDNORM;
printk("poll wait\n");
return mask;
}
static int key_open(struct inode *inode, struct file *file)
{
int num;
if(file->f_flags & O_NONBLOCK) {
if(down_trylock(&key_lock)) return -EBUSY;
}
else {
down(&key_lock);
}
//为每个按键注册中断处理程序
for(num=0;num<KEYNUM;num++) {
request_irq(key_irqs[num].irq, keys_interrupt, key_irqs[num].flags, key_irqs[num].name, (void *)&press_cnt[num]);
}
return 0;
}
static int key_close(struct inode *inode, struct file *file)
{
int num;
//释放中断号
for(num=0;num<6;num++) {
free_irq(key_irqs[num].irq, (void *)&press_cnt[num]);
}
up(&key_lock);
printk("key_close free irqs\n");
return 0;
}
static int key_read(struct file *filp, char __user *buff, size_t count, loff_t *offp)
{
// unsigned int err;
//判断是阻塞读还是非阻塞读
if(filp->f_flags & O_NONBLOCK) {
if(!ev_press) return -EAGAIN;
}
else {
/*if ev_press==0,then sleep*/
/*阻塞，当有按键按下时(中断)被唤醒*/
wait_event_interruptible(key_waitq,ev_press);
}
//阻塞结束，有键按下了
ev_press = 0;
//拷贝数据到用户空间
copy_to_user(buff,(const void *)press_cnt,min(sizeof(press_cnt),count));
memset((void *)press_cnt,0,sizeof(press_cnt));
// printk("read and clean press_cnt\n");
return 1;
}
static struct file_operations key_ops = {
.owner = THIS_MODULE,
.open = key_open,
.release = key_close,
.read = key_read,
.poll = key_poll,
.fasync = key_fasync,
};
static struct cdev *cdev_keyint;
static struct class *keyint_class;
//模块初始化函数
static int __init s3c6410_keyint_init(void) {
int val;
/*timer initial */
init_timer(&key_timer);
key_timer.function = key_timer_func;
add_timer(&key_timer);
/*初始化信号量*/
init_MUTEX(&key_lock);
/*register device*/
val = alloc_chrdev_region(&devid,0,1,DEVICE_NAME);
if(val) {
return -1;
printk("register keyint error\n");
}
cdev_keyint = cdev_alloc();
cdev_init(cdev_keyint, &key_ops);
cdev_keyint->owner = THIS_MODULE;
cdev_keyint->ops = &key_ops;
val = cdev_add(cdev_keyint,devid,1);
if(val) {
return -1;
printk("add device error\n");
}
keyint_class = class_create(THIS_MODULE,DEVICE_NAME);
device_create(keyint_class,NULL,devid,NULL,"%s",DEVICE_NAME);
printk("KEY initialezed ^_^\n");
return 0;
}
static void __exit s3c6410_keyint_exit(void)
{
cdev_del(cdev_keyint);
device_destroy(keyint_class,devid);
class_destroy(keyint_class);
unregister_chrdev_region(devid,1);
}
module_init(s3c6410_keyint_init);
module_exit(s3c6410_keyint_exit);
MODULE_LICENSE("GPL");
Makefile
ifneq ($(KERNELRELEASE),) obj-m := key.o else KDIR := /forlinux/linux-3.0.1 all: make -C $(KDIR) M=$(PWD) modules ARCH=arm CROSS_COMPILE=arm-linux- clean: rm -f *.ko *.o *.mod.o *.mod.c *.symvers endif
产生.ko文件进行安装模块和设备 insmod，这里不需要mknod因为函数里调用了class_create和device_create会自动创建设备节点。
测试代码
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
int main(int argc, char **argv)
{
int fd;
int val;
int i;
int key_value[6];
fd = open("/dev/keybutton",0);
if(fd<0) {
printf("open devie error\n");
return -1;
}
while(1) {
val = read(fd,key_value, sizeof(key_value));
if(val<0) {
printf("read error\n");
continue;
}
for(i=0;i<6;i++) {
if(key_value[i])
printf("KEY%d pressed\n",(i+1),key_value[i]);
}
}
close(fd);
return 0;
}