keyboard.c

该源码是创维特ARM7 JX44B0X板的例子程序

#include <stdio.h>
#include <sys/time.h>
#include <signal.h>
#include "../include/44b.h"

struct timeval key_tpstart;

char key_get_char(int row, int col)
{
        char key;
 
        switch( row )
        {
        case 0:
                if((col & 0x01) == 0) key = '7';
                else if((col & 0x02) == 0) key = '1';
                else if((col & 0x04) == 0) key = '0';
                else if((col & 0x08) == 0) key = '4';
                break;
        case 1:
                if((col & 0x01) == 0) key = '8';
                else if((col & 0x02) == 0) key = '2';
                else if((col & 0x04) == 0) key = 'A';
                else if((col & 0x08) == 0) key = '5';
                break;
        case 2:
                if((col & 0x01) == 0) key = '9';
                else if((col & 0x02) == 0) key = '3';
                else if((col & 0x04) == 0) key = 'B';
                else if((col & 0x08) == 0) key = '6';
                break;
        case 3:
                if((col & 0x01) == 0) key = 'E';
                else if((col & 0x02) == 0) key = 'C';
                else if((col & 0x04) == 0) key = 'F';
                else if((col & 0x08) == 0) key = 'D';
                break;
        default:
                break;
        }
        return key;
}

#define RECV_CMD_MAX_BUF 2048
char recv_buf[RECV_CMD_MAX_BUF];
int  recv_read = 0;
int  recv_write = 0;
                                                                                       
char key_recv_buf[RECV_CMD_MAX_BUF];
int  key_recv_read = 0;
int  key_recv_write = 0;

enum KEYBOARD_SCAN_STATUS
{
        KEYBOARD_SCAN_FIRST,
        KEYBOARD_SCAN_SECOND,
        KEYBOARD_SCAN_THIRD,
        KEYBOARD_SCAN_FOURTH
};
int row = 0;
unsigned char output_0x02000000=0xff;
unsigned char   ascii_key, input_key[4], input_key1[4], key_mask = 0x0F;
unsigned char*  keyboard_port_scan = (unsigned char*)0x02000000;
unsigned char*  keyboard_port_value = (unsigned char*)0x02000002;
int              keyboard_scan_status[4] = {
                                                                                       
                         KEYBOARD_SCAN_FIRST,
                                                                                       
                         KEYBOARD_SCAN_FIRST,
                                                                                       
                         KEYBOARD_SCAN_FIRST,
                                                                                       
                         KEYBOARD_SCAN_FIRST
                                                                                       
                   };

void key_recv_key(int key)
{
        key_recv_buf[key_recv_write] = key;
        key_recv_write ++;
        if(key_recv_write >= RECV_CMD_MAX_BUF)
                key_recv_write = 0;
                                                                                       
        if(key_recv_write == key_recv_read)
        {
                key_recv_read ++;
                if(key_recv_read >= RECV_CMD_MAX_BUF)
                        key_recv_read = 0;
        }
}

void Kbd_Scan(void)
{
        int loopcnt = row, bexit = 0;
        int temp;
 
        for( loopcnt = row; loopcnt < row + 4; loopcnt ++)
        {
                if(loopcnt >= 4)
                        temp = loopcnt - 4;
                else
                        temp = loopcnt;
                switch(keyboard_scan_status[temp])
                {
                        case KEYBOARD_SCAN_FIRST:
                                *keyboard_port_scan = output_0x02000000 & (~(0x00000001<<temp));
                                keyboard_scan_status[temp] = KEYBOARD_SCAN_SECOND;
                                bexit = 1;
                                break;
                        case KEYBOARD_SCAN_SECOND:
                                input_key[temp] = (*keyboard_port_value) & key_mask;  
                                if(input_key[temp] == key_mask)
                                        keyboard_scan_status[temp] = KEYBOARD_SCAN_FIRST;     
                                else
                                {
                                        keyboard_scan_status[temp] = KEYBOARD_SCAN_THIRD;
                                        bexit = 1;
                                }
                                break;
                        case KEYBOARD_SCAN_THIRD:
                                if (((*keyboard_port_value) & key_mask) != input_key[temp])
                                        keyboard_scan_status[temp] = KEYBOARD_SCAN_FIRST;
                                else
                                {
                                        ascii_key = key_get_char(temp, input_key[temp]);
                                        keyboard_scan_status[temp] = KEYBOARD_SCAN_FOURTH;
 
                                        *keyboard_port_scan = output_0x02000000 & (~(0x00000001<<temp));
                                        bexit = 1;
                                }
                                break;
                        case KEYBOARD_SCAN_FOURTH:
                                input_key1[temp] = (*keyboard_port_value) & key_mask; 
                                if(input_key1[temp] == key_mask)
                                {
                                        key_recv_key(ascii_key);
                                        keyboard_scan_status[temp] = KEYBOARD_SCAN_FIRST;
                                }else
                                {
                                        *keyboard_port_scan = output_0x02000000 & (~(0x00000001<<temp));   
                                        bexit = 1;
                                }
                                break;
                }
                if(bexit)
                        break;
        }
 
        row = temp;
}

char DrvKeyGet()
{
        char ch;
 
        if(key_recv_write == key_recv_read)
        {
                /* no key found */
                ch = 0;
        }else
        {
                ch = key_recv_buf[key_recv_read];
                key_recv_read ++;
                if(key_recv_read >= RECV_CMD_MAX_BUF)
                        key_recv_read = 0;
        }
        return ch;
}

char DrvKeyGetNoDel()
{
        char ch;
 
        if(key_recv_write == key_recv_read)
        {
                /* no key found */
                ch = 0;
        }else
        {
                ch = key_recv_buf[key_recv_read];
        }
        return ch;
}

void key_timer(int signo)
{
	Kbd_Scan();
	pulse_timer();
	ad_poll_timer();
} 

void key_init_sigaction(void)
{
    struct sigaction act;
    act.sa_handler=key_timer;
    act.sa_flags=0;
    sigemptyset(&act.sa_mask);
    sigaction(SIGPROF,&act,NULL);

    /* begin get the time */
    gettimeofday(&key_tpstart,NULL);
}

void key_init_time()
{
    struct itimerval value;
    value.it_value.tv_sec=0;
    value.it_value.tv_usec=1;
    value.it_interval=value.it_value;
    setitimer(ITIMER_PROF,&value,NULL);
}

void key_init()
{
    key_init_sigaction();
    key_init_time();
}