s3c2440_kb.c

键盘驱动程序

/**********************************************************
 * s3c2440-ts.c
 *
 * keyboard driver for S3C2440 based PDA
 *
 *
 * History:
 *
 *
 ***********************************************************/

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/poll.h>
#include <linux/spinlock.h>
#include <asm/irq.h>
#include <asm/arch/irq.h>
#include <asm/arch/irqs.h>
#include <asm/arch/clocks.h>
#include <asm/hardware.h>
#include <asm/arch/S3C2440.h>

#define DEVICE_NAME	"s3c2440-kb" //键盘设备名

static int kbMajor = 0; //默认的主设备号

#define MAX_KB_BUF	10 //循环队列的尺寸	

typedef struct {
	unsigned int keyStatus;
	int irq;
//	int timeCount;
	u_short buf[MAX_KB_BUF];		/* 循环队列*/
	unsigned int head, tail;	/* 循环队列的读写指针*/
	spinlock_t lock;			/*锁*/
} KB_DEV;

static KB_DEV kbdev;

#define KEY_UP		0  //按键弹起
#define KEY_DOWN	1	//按键按下
#define NO_KEY_DOWN 2  //没有键按下

#define EINT1_DOWN	0
#define EINT3_DOWN	1
#define EINT8_DOWN  2
#define NO_EINT_DOWN 3

/*循环队列操作*/
#define BUF_HEAD	(kbdev.buf[kbdev.head])
#define BUF_TAIL	(kbdev.buf[kbdev.tail])
#define INCBUF(x) 	if((++x)==MAX_KB_BUF) x=0

/*定时器设置*/
#define KB_TIMER_DELAY  (HZ/50) /*HZ表示每秒产生的时钟滴答数,定时器超时为20ms*/
#define REPEAT_START_DELAY  (HZ) /* 自动重复开始延时:1秒*/
#define REPEAT_DELAY (HZ/2)		/*自动重复延时:0.5秒*/

static struct timer_list kb_timer;
static struct timer_list repeat_timer;
spinlock_t repeat_lock;
static int timeCount =1;
static int TIME_OUT  =5;

/*键盘矩阵*/

static u_short keyboard_code_map[4][3]={
											{1 , 2 , 3 },
											{4 , 5 , 6 },
											{7 , 8 , 9 },
											{10, 11, 12}
										}; //每个按键对应的键盘码
static u_short pre_keyboard_code  = 0; //上次扫描得到的按键值
static u_short curr_keyboard_code = 0;//当前扫描得到的按键值
static u_short snap_keyboard_code[4][3]={
											{0 , 0 , 0 },
											{0 , 0 , 0 },
											{0 , 0 , 0 },
											{0,  0,  0}
										}; //临时按键值
#define DETECTION_THROLD	3


static int requestIrq();
static int s3c2440_kb_release(struct inode *inode, struct file *filp);



/*----------------------------------------------------
*  func: 初始化GPJCON寄存器,将GPJ9,GPJ10,GPJ11,GPJ12
*        配置成output管腿
*  
------------------------------------------------------*/
static void init_gpjcon()
{
	
	//GPJ9,GPJ10,GPJ11,GPJ12------>output
	GPJCON &= 0xFC03FFFF;
	GPJCON |= 0x01540000;
}

/*----------------------------------------------------
*  func:  向GPJ9,GPJ10,GPJ11,GPJ12输出value
*  param: 
*        value: 输出值
*  
------------------------------------------------------*/
//
static inline void output_giop(int value )  //往所有行输出
{
	value &= 0x0000000F;
	value <<= 9;
	GPJDAT &= 0xE1FF;
	GPJDAT |= value;
	udelay(2);
}

/*----------------------------------------------------
*  func:  判断eint当前是否是低电平
*  param: 
*        irq: 当前引发中断的eint的irq号
*  return: 
*           EINT1_DOWN: eint1上是低电平
*           EINT3_DOWN: eint3上是低电平
*           EINT8_DOWN: eint8上是低电平
*			NO_EINT_DOWN:eint上不是低电平
------------------------------------------------------*/
int get_eint_value(int irq)
{
	u_int IOValue;

	IOValue = GPFDAT ;
	
	if( (irq == 1) && (( IOValue & 0x00000002)==0)    )              
	{		
			return EINT1_DOWN;
	}
	if((irq ==3 ) && (( IOValue & 0x00000008)==0) )
	{
		return EINT3_DOWN;
	}
	IOValue = GPGDAT ;
	if((irq ==36) && (( IOValue & 0x0000001)==0) )
	{
		
		 return EINT8_DOWN;
	}

	return NO_EINT_DOWN;

}

/*----------------------------------------------------
*  func:  扫描键盘,判断哪一个键被按下
*  param: 
*        x: 得到按键的行号
*		 y: 得到按键的列号
*  return: 
*           KEY_DOWN: 键盘上有键被按下
*           NO_KEY_DOWN: 键盘上没有键被按下
------------------------------------------------------*/

static inline int scan_keyboard(int* x,int* y)
{
	int matrix_row,matrix_col,matrix_col_status;

	output_giop(0xF);  //往所有行输出1
	

	//判断按键在哪一行
	matrix_row=matrix_col=-1;

	output_giop(0xE);//在第1行上输出1，其余行输出0
	matrix_col_status = get_eint_value(kbdev.irq);
	if(matrix_col_status != NO_EINT_DOWN)
	{
		matrix_row = 0;
		matrix_col = matrix_col_status;
		goto scanend;

	}

	output_giop(0xD);//在第2行上输出1，其余行输出0

	matrix_col_status = get_eint_value(kbdev.irq);
	if(matrix_col_status != NO_EINT_DOWN)
	{
		matrix_row=1;
		matrix_col = matrix_col_status;
		goto scanend;


	}

	output_giop(0xB);//在第3行上输出1，其余行输出0
	matrix_col_status =get_eint_value(kbdev.irq);
	if(matrix_col_status != NO_EINT_DOWN)
	{
		matrix_row=2;
		matrix_col = matrix_col_status;
		goto scanend;


	}

	output_giop(0x7);//在第4行上输出1，其余行输出0
	matrix_col_status =get_eint_value(kbdev.irq);
	if(matrix_col_status != NO_EINT_DOWN)
	{
		matrix_row=3;
		matrix_col = matrix_col_status;
		goto scanend;


	}
scanend:
	output_giop(0);
	if(matrix_row >=0 )
	{
		snap_keyboard_code[matrix_row][matrix_col_status]= snap_keyboard_code[matrix_row][matrix_col_status] + 1;
		if(snap_keyboard_code[matrix_row][matrix_col]>=DETECTION_THROLD)
		{
			*x=matrix_row;
			*y=matrix_col;
			curr_keyboard_code = keyboard_code_map[matrix_row][matrix_col];
			return KEY_DOWN;
		}


	}
	return NO_KEY_DOWN;

}

/*----------------------------------------------------
*  func:  判断本次按键是否与上次按键相同
*  param: 
*        
*  return: 
*           0: 相同
*           1: 不同
------------------------------------------------------*/
static inline int key_changed()
{
	
	return (pre_keyboard_code == curr_keyboard_code)? 0 : 1;
}

/*----------------------------------------------------
*  func:  将按键对应的键盘码保存到循环队列中
*  param: 
*        keyValue: 按键的对应的键盘码

*  return: 
*                   
------------------------------------------------------*/

static inline void save_key_to_queue(u_short keyValue)
{
	if (kbdev.keyStatus == KEY_DOWN)
	{
		BUF_HEAD = keyValue;
		INCBUF(kbdev.head);
		//wake_up_interruptible(&(kbdev.wq));
	}

}

/*----------------------------------------------------
*  func:  重复按键定时器处理程序,如果一直按住某键,
          则将该键的键盘码定时存到循环队列中
*  param: 
*        data: 无参数

*  return: 
*                   
------------------------------------------------------*/
static inline void repeat_timer_handler(unsigned long data)
{
	spin_lock_irq(&(repeat_lock));

	if(kbdev.keyStatus ==KEY_DOWN)
	{
		repeat_timer.expires = jiffies + REPEAT_DELAY;//设置自动重复延时
		add_timer(&repeat_timer);//将定时器加入队列
		if(pre_keyboard_code != 0)
		{
			//printk("repeat save keyvalue\n   %d",pre_keyboard_code);
			save_key_to_queue(pre_keyboard_code);//将按键值存入循环队列
		}
	}
	else//如果按键弹起
	{
		//del_timer(&repeat_timer);
	//	printk("del repeat timer\n");
	}

	spin_unlock_irq(&(repeat_lock));


}

/*----------------------------------------------------
*  func:  使能中断
*  param: 
*  return: 
*                   
------------------------------------------------------*/
//使能中断
static inline void enableIrq()
{
	//清除SRCPND寄存器中eint1 eint2 eint8相应位
	SRCPND = 0x0000002A;
	//使能中断
	enable_irq(IRQ_EINT1);
	enable_irq(IRQ_EINT3);
	enable_irq(IRQ_EINT8);

}

/*----------------------------------------------------
*  func:  键盘定时扫描程序,如果得到稳定键码,将键码存
*		  入循环队列;如果没有,则延时20ms后继续扫描
*  param: 
*        data: 无参数

*  return: 
*                   
------------------------------------------------------*/
static inline void kb_timer_handler(unsigned long data)
{
	int x,y;
	spin_lock_irq(&(kbdev.lock));
	x = y = 0;
	
	
	if(scan_keyboard(&x,&y) == KEY_DOWN)
	{
	//	printk("snap_keyboard_code=%d, %d, %d, %d\n", snap_keyboard_code[0][1],snap_keyboard_code[1][1],snap_keyboard_code[2][1],snap_keyboard_code[3][1]);
		kbdev.keyStatus =KEY_DOWN;