Linux_arm驱动之按键模拟脉冲实现定时器的精确计时

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Linux_arm驱动之按键模拟脉冲实现定时器的精确计时

2024-08-30 01:24:47 218人阅读

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/*****************************************************************
内核驱动部分button_ker.c
*****************************************************************/
/*
*应用内核定时器简单实现计时的功能
*但是内核定时器精确度最小就为50ms
*较4_button_timer完善功能：利用硬件的定时器计时
*精确度提高
*应用linux-2.6.32.2内核里arch/arm/plat_s3/timer.c
*实现对定时器的精确提高问题
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/irq.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <linux/timer.h>
#include <linux/sched.h>
//*****///
#include <linux/clk.h>
#include <plat/regs-timer.h>
#include <asm/io.h>
///****///
#include <linux/miscdevice.h>
#include <mach/regs-irq.h>
//#include <linux/platform_device.h>
//#include <linux/miscdevice.h>
//#include <mach/regs-gpio.h>
#include <linux/wait.h>
#define DEVICE_NAME "timer_test"
#define BUTTON_MAJOR 240
#define TIMER_IOCTL_SET_FREQ 1
#define TIMER_IOCTL_STOP 0
static struct semaphore lock;
struct button_irq_desc{
int irq;
unsigned long flags;
int num;
char *name;
};
//用来指定按键所有的外部中断引脚以及中断出发方式和名字
static struct button_irq_desc button_irqs[] = {
{IRQ_EINT0,IRQF_TRIGGER_FALLING,1,"KEY1"},
{IRQ_EINT1,IRQF_TRIGGER_FALLING,2,"KEY2"},
{IRQ_EINT2,IRQF_TRIGGER_FALLING,3,"KEY3"},
{IRQ_EINT4,IRQF_TRIGGER_FALLING,4,"KEY4"},
};
static volatile char key_values[4]={‘0‘,‘0‘,‘0‘,‘0‘};
static DECLARE_WAIT_QUEUE_HEAD(button_waitq);
static volatile int ev_press =0;
static void timer_open(void);
static void timer_stop(void);
static inline int timer_interrupt_pending(void);
static unsigned long get_timer_offset(void);
///********************************////
static volatile bool value=http://www.mamicode.com/false;
static volatile unsigned long count = 0;
static volatile unsigned long freq_value = 500;
static volatile unsigned long tcnt_value = 50625;
//定时器中断函数
static irqreturn_t timer_interrupt_function(int irq,void *dev_id)
{
count++;
//printk("timer_interrupt occur!\n");
return IRQ_HANDLED;
}
//时间处理函数
static void timer_second_manage(unsigned long second_value)
{
static volatile unsigned long ss_value1 = 0;
static volatile unsigned long ms_value2 = 0;
static volatile unsigned long us_value3 = 0;
us_value3 = //(second_value*10000/tcnt_value)*1000/freq_value/10;
(second_value*1000/freq_value)*10000/tcnt_value/10;
ms_value2 = (count%freq_value)*1000/freq_value + us_value3/1000;
ss_value1 = count/freq_value + ms_value2/1000;
printk("++++++++++++++++++++++++\n");
printk("used time:%lu n\n",count);
printk("the second_value :%lu n\n",second_value);
printk("used time:%lu.%03lu %03lu s\n",ss_value1,
ms_value2%1000,us_value3%1000);
printk("++++++++++++++++++++++++\n");
}
//外部中断函数
static irqreturn_t button_interrupt(int irq,void *dev_id){
unsigned long second_value = 0;
int num= ((struct button_irq_desc *)dev_id)->num;
switch(num){
case 2://17
value=http://www.mamicode.com/false;
timer_stop();
printk("key1 press\n");
break;
case 4://48
if(!value) {
value=http://www.mamicode.com/true; count=0;
timer_open();
}else {
timer_stop();
second_value=http://www.mamicode.com/get_timer_offset();
timer_second_manage(second_value);
value=http://www.mamicode.com/false;
}
printk("key2 press\n");
break;
case 3://18
value=http://www.mamicode.com/false;
timer_stop();
printk("key3 press\n");
break;
case 1://16
value=http://www.mamicode.com/false;
timer_stop();
printk("key4 press\n");
break;
default:
printk("num error,nothing to do!\n");
}
//ev_press=1;
//wake_up_interruptible(&button_waitq);
return IRQ_HANDLED;
}
//频率设置函数
//freq: pclk/50/16/65536~pclk/50/16
//if : pclk=50mhz freq is 1Hz~62500Hz
//human ear : 20Hz~20000Hz
//
static void timer_set_freq(unsigned long freq)
{
unsigned long tcon;
unsigned long tcnt;
unsigned long tcfg0;
unsigned long tcfg1;
struct clk *clk_p;
unsigned long pclk;
tcon = __raw_readl(S3C2410_TCON);
tcfg0 = __raw_readl(S3C2410_TCFG0);
tcfg1 = __raw_readl(S3C2410_TCFG1);
tcfg0 &= ~(255<<0);
//tcfg0 |= (50-1);
tcfg0 |= 0;
tcfg1 &= ~(15<<0);
tcfg1 |= (0<<0);
__raw_writel(tcfg0,S3C2410_TCFG0);
__raw_writel(tcfg1,S3C2410_TCFG1);
clk_p = clk_get(NULL,"pclk");
pclk = clk_get_rate(clk_p);
printk("the pclk is : %ld\n",pclk);
//tcnt = (pclk/50/16)/freq;
tcnt = (pclk/2)/freq;
tcnt_value = tcnt;
printk("the tcnt is %ld\n",tcnt);
__raw_writel(tcnt,S3C2410_TCNTB(0));
__raw_writel(0,S3C2410_TCMPB(0));
//tcon &= ~0x1f;
tcon &= ~0x1e;
tcon |=0xb;
__raw_writel(tcon,S3C2410_TCON);
tcon &= ~2;
__raw_writel(tcon,S3C2410_TCON);
}
static void timer_open(void)
{
unsigned long tcon = 0;
//printk("***1>tcnto is :%u\n",__raw_readl(S3C2410_TCNTO(0)));
tcon = __raw_readl(S3C2410_TCON);
tcon |= 1;
__raw_writel(tcon,S3C2410_TCON);
//printk("***2>tcnto is :%u\n",__raw_readl(S3C2410_TCNTO(0)));
}
static void timer_stop(void)
{
unsigned long tcon;
tcon = __raw_readl(S3C2410_TCON);
tcon &= ~1;
__raw_writel(tcon,S3C2410_TCON);
}
#define SRCPND_TIMER0 (1<<(IRQ_TIMER0 - IRQ_TIMER0))
//中断识别函数查看在按键产生中断时，定时器是否也在中断中
static inline int timer_interrupt_pending(void)
{
return __raw_readl(S3C2410_SRCPND) & SRCPND_TIMER0;
}
//计算中断寄存器中TCNTO0中的偏移量
static unsigned long get_timer_offset (void)
{
unsigned long tdone;
unsigned long tval;
tdone = (tcnt_value -__raw_readl(S3C2410_TCNTO(0)));
if(timer_interrupt_pending()) {
tval = __raw_readl(S3C2410_TCNTO(0));
tdone = tcnt_value - tval;
if(!tval)
tdone += tcnt_value;
}
return tdone;
}
static struct irqaction timer_irq = {
.name = "S3C2410 Timer Tick",
.flags = IRQF_DISABLED |IRQF_TIMER|IRQF_IRQPOLL,
.handler = timer_interrupt_function,
.dev_id = NULL
};
static int button_open(struct inode *inode,struct file *file)
{
int i,err;
if(down_trylock(&lock)){
printk("down_trylock failed!\n");
return -EBUSY;
}
if(setup_irq(IRQ_TIMER0,&timer_irq)){
printk("setup_irq failed!\n");
return -EBUSY;
}
for(i=0;i<sizeof(button_irqs)/sizeof(button_irqs[0]);i++) {
err=request_irq(button_irqs[i].irq,button_interrupt,button_irqs[i].flags,
button_irqs[i].name,(void*)&(button_irqs[i]));
if(err)
break;
}
if(err) {
for(--i;i>=0;i--)
free_irq(button_irqs[i].irq,(void *)&button_irqs[i].num);
printk("request_irq error!\n");
return -1;
}
disable_irq(IRQ_EINT0);
disable_irq(IRQ_EINT1);
disable_irq(IRQ_EINT2);
disable_irq(IRQ_EINT4);
set_irq_type(IRQ_EINT0,IRQ_TYPE_LEVEL_LOW);//key4
set_irq_type(IRQ_EINT1,IRQ_TYPE_EDGE_RISING);//key1
set_irq_type(IRQ_EINT2,IRQ_TYPE_EDGE_FALLING);//key3
//set_irq_type(IRQ_EINT4,IRQ_TYPE_EDGE_BOTH);//key2
set_irq_type(IRQ_EINT4,IRQ_TYPE_EDGE_FALLING);//key2
enable_irq(IRQ_EINT0);
enable_irq(IRQ_EINT1);
enable_irq(IRQ_EINT2);
enable_irq(IRQ_EINT4);
return 0;
}
static int button_close(struct inode *inode,struct file *file)
{
int i;
for(i=0;i<sizeof(button_irqs)/sizeof(button_irqs[0]);i++) {
free_irq(button_irqs[i].irq,(void *)&button_irqs[i]);
}
remove_irq(IRQ_TIMER0,&timer_irq);
up(&lock);
return 0;
}
static int button_read(struct file *filp,char __user *buff,
size_t count,loff_t *offp)
{
unsigned long err;
if(filp->f_flags & O_NONBLOCK)
return -EAGAIN;
else {
wait_event_interruptible(button_waitq,ev_press);
}
ev_press=0;
err=copy_to_user(buff,(const void*)key_values,
min(sizeof(key_values),count));
return err ? -EFAULT : min(sizeof(key_values),count);
}
static int timer_ioctl(struct inode *inode,struct file *file,
unsigned int cmd,unsigned long arg)
{
switch (cmd) {
case TIMER_IOCTL_SET_FREQ:
printk("timer_ioctl_set_freq\n");
if(arg==0)
return -EINVAL;
timer_set_freq(arg);
freq_value = arg;
break;
case TIMER_IOCTL_STOP:
printk("timer_ioctl_stop\n");
timer_stop();
break;
}
return 0;
}
static struct file_operations button_fops = {
.owner = THIS_MODULE,
.open = button_open,
.read = button_read,
.release = button_close,
.ioctl = timer_ioctl,
};
static struct miscdevice misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DEVICE_NAME,
.fops = &button_fops,
};
//初始化函数
static int __init button_init(void)
{
init_MUTEX(&lock);
/*
if(register_chrdev(BUTTON_MAJOR,DEVICE_NAME,&button_fops)<0) {
printk(DEVICE_NAME"can‘t register major number!\n");
return -1;
}
printk(DEVICE_NAME"register sucess!\n");
*/
if(misc_register(&misc)<0) {
printk(DEVICE_NAME"can‘t register major number!\n");
return -1;
}
printk(DEVICE_NAME"register sucess!\n");
return 0;
}
static void __exit button_exit(void)
{
timer_stop();
//unregister_chrdev(BUTTON_MAJOR,DEVICE_NAME);
misc_deregister(&misc);
}
module_init(button_init);
module_exit(button_exit);
MODULE_LICENSE("GPL");

[cpp] view plaincopy

/**********************************************************************
应用程序部分button_app.c
**********************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#define msleep(x) usleep(x*1000);
#define TIMER_IOCTL_SET_FREQ 1
#define TIMER_IOCTL_STOP 0
int main(int argc,char **argv)
{
int fd;
int ioarg=500;
int press_cnt[4]={0};
if((fd=open("/dev/timer_test",0))<0){
printf("Can‘t open /dev/timer_test~!");
return -1;
}
printf("sleep begin...\n");
ioctl(fd,TIMER_IOCTL_SET_FREQ,ioarg);
//msleep(70000);
while(1)
usleep(11111);
ioctl(fd,TIMER_IOCTL_STOP);
printf("sleep end...\n");
close(fd);
return 0;
}

[cpp] view plaincopy

/***************************************************************
makefile部分
****************************************************************/
ifneq ($(KERNELRELEASE),)
obj-m := button_ker.o
else
KDIR :=/home/kernel/linux-2.6.32.2
all:
make -C $(KDIR) M=$(PWD) modules ARCH=arm CROSS_COMPILE=arm-linux-
arm-linux-gcc button_app.c -o button_app
clean:
rm -f *.ko *.o *.mod.o *.mod.c *.symvers modul*

Linux_arm驱动之按键模拟脉冲实现定时器的精确计时

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Linux_arm驱动之按键模拟脉冲实现定时器的精确计时

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