s5pv210使用查询方式实现按键灯操作

用TQ210写了个使用查询的方法实现按键灯的操作，具体实现方法如下：

1、原理图

由原理图可知，按键不按下的时候CPU检测到的是高电平，按下时处于低电平，以KEY1为例，KEY1连的是XIENT0,查芯片手册



由芯片手册可知XEINT0连的是GPH0_0脚，因此需要配置GPH0_0为输入脚，在此就不详述怎么配置输入了同时可看LED灯原理图



由原理图可知要使LED1灯亮，则必须使GPC0_3输出低电平,在知道上面原理后则可写出程序了，以下的程序则实现按按键1则1灯亮2灯灭，按KEY2则2灯亮1灯灭，驱动程序如下：

#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 <linux/device.h>

typedef struct {
struct class *leddrv_class;
struct device	*leddrv_class_dev;
int irq;
int major;
}CharLedDrive;
static CharLedDrive led_info;
volatile unsigned long virt, phys;//用于存放虚拟地址和物理地址
volatile unsigned long *GPC0CON, *GPC0DAT;//用与存放两个个寄存器的地址
volatile unsigned long *GPH0CON, *GPH0DAT;//按键

static void all_led_off(void);
static void led_config(void)
{
phys = 0xE0200060;
//0xE020_0C00 gph0con
//在虚拟地址空间中申请一块长度为0x10的连续空间
//这样，物理地址phys到phys+0x10对应虚拟地址virt到virt+0x10
virt =(unsigned long)ioremap(phys, 0xf00);
GPC0CON = (unsigned long *)(virt + 0x00);//指定需要操作的三个寄存器的地址
GPC0DAT = (unsigned long *)(virt + 0x04);
GPH0CON = (unsigned long *)(virt + 0xc00-0x60); //keY1配置为输入
GPH0DAT = (unsigned long *)(virt + 0xc00-0x60+0x04);
*GPC0CON &= ~(0xFF << 12);
*GPC0CON |= 0x11 << 12;			// 配置GPC0_3和GPC0_4为输出
*GPH0CON &= ~0x0F; //配置为输入
all_led_off();
}

static void led1_on(void)
{
*GPC0DAT |= 1 << 3;
*GPC0DAT &= ~(0x01 << 4);
}

static void led2_on(void)
{
*GPC0DAT |= 1 << 4;
*GPC0DAT &= ~(0x01 << 3);
}

static void led_on(void)
{
*GPC0DAT |= 1 << 3;		// 点亮LED1
*GPC0DAT |= 1 << 4;		// 点亮LED2
}
static void all_led_off(void)
{

*GPC0DAT &= ~(0x3 << 3);		// 熄灭LED1和LED2

}

static int led_drv_open(struct inode *inode, struct file *file)
{
printk("led_drv_open\n");

led_config();
all_led_off();
//	led_on();
return 0;
}

static ssize_t led_drv_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos)
{
char val = 0;
//printk("first_drv_write\n");
int ret = -1;
ret = copy_from_user(&val, buf, count); //	copy_to_user();
if(ret)
{
printk("write ret= %x\n",ret);
}
printk("led process %c\n",val);
switch(val)
{
case '1':
*GPC0DAT |= 1 << 3;		// 点亮LED1
*GPC0DAT &= ~(1 << 4);		//灭2
break;
case '2':
*GPC0DAT |= 1 << 4;
*GPC0DAT &= ~(1 << 3);
break;
case '3':
led_on();
break;
case '4':
all_led_off();
break;
default:
all_led_off();
break;
}
printk("2222\n");
return 0;
}

static ssize_t led_drv_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{

unsigned int key[4];
unsigned int temp;

int ret =-1;
temp = *GPH0DAT;
//下面是获取按键状态，按下时为低电平0
key[0] = (!(temp & (0x1<<0)))?1:0;
key[1] = (!(temp & (0x1<<1)))?2:0;
key[2] = (!(temp & (0x1<<2)))?3:0;
key[3] = (!(temp & (0x1<<4)))?4:0;
ret=copy_to_user(buf, key, sizeof(key));//从内核向用户空间传数据
if(ret)
{
printk("ret = %x\n",ret);
}

if(!(temp&0x01) && (temp&0x02))
{
led1_on();
printk("led1_on\n");
}
else if((temp&0x01) && !(temp&0x02))
{
led2_on();
printk("led2_on\n");
}
else
{
all_led_off();
}
return 0;
}

static struct file_operations led_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   =   led_drv_open,
.write	=	led_drv_write,
.read		= led_drv_read,
};

//static irqreturn_t led_handler(int irq, void *dev_id)

static int led_drv_init(void)
{
led_info.major = register_chrdev(0, "led_drv", &led_drv_fops); // 注册, 告诉内核

led_info.leddrv_class = class_create(THIS_MODULE, "leddrv");

led_info.leddrv_class_dev = device_create(led_info.leddrv_class, NULL, MKDEV(led_info.major, 0), NULL, "led"); /* /dev/xyz */
/*
if(request_irq(led_info.led_irq,led_handler, unsigned long flags,
const char *name, void *dev))
{
printk(KERN_WARNING "Led: Unable to allocate IRQ\n");
led_info.led_irq = 0;

}
*/
//gpbcon = (volatile unsigned long *)ioremap(0xE0200060, 16);
//gpbdat = gpbcon + 1;

return 0;
}

static void led_drv_exit(void)
{
all_led_off();
unregister_chrdev(led_info.major, "led_drv"); // 卸载

device_unregister(led_info.leddrv_class_dev);
class_destroy(led_info.leddrv_class);
iounmap((void *)virt); //撤销映射关系
}

module_init(led_drv_init);
module_exit(led_drv_exit);

MODULE_LICENSE("GPL");

接下来是测试程序：

#include<stdio.h>
#include<stdlib.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include <unistd.h>

int main(int argc,char **argv)
{
int fd = -1;
char val = 0;
char buf[10]={0};
int temp= 0;
char *s = malloc(100);
unsigned int key[4];
fd = open("/dev/led_drv",O_RDWR);
if(fd<0)
printf("can't open \n");
/*
while(1)
{
printf("输入1：1灯亮\n输入2：2灯亮\n输入3：所有灯亮\n输入4：所有灯灭\n输入5：退出\n请输入");
scanf("%s",s);
getchar();
val = s[0];
write(fd,&val,1);
if(val == '5')
break;
}
*/
while(1)
{
val++;
read(fd,key,sizeof(key));
temp =key[0]?1:(key[1]?2:(key[2]?3:(key[3]?4:0)));
if(temp)
printf("pressed key is key[%x]\n",temp);
temp = 0;

}
free(s);
return 0;

}

以上是查询方式实现的，查询方式消耗cpu资源比较严重，下一篇将用中断方式实现