key_scan_no_reg

基于linux操作系统ATMELARM9200 开发平台的键盘驱动程序开发

/***********************************************************************
 *
 * (C) Copyright 2004,12
 * 
 * Himai tech
 * All rights left.
 *
 *
 * a simple Device Driver for HM901ESP led device
 *
 * Can be loaded as module
 *
 * $Id: led.c,v 1.1 2004/12/15  $
 *
 ***********************************************************************/

/*
 * Standard in kernel modules
 */
#include <linux/kernel.h>	/* We're doing kernel work	*/
#include <linux/module.h>	/* Specifically, a module	*/
#include <asm/uaccess.h>	/* for put_user			*/
#include <linux/init.h>		/* for __initfunc		*/
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/interrupt.h>    
#include <linux/timer.h>
#include <asm/io.h>        	/* for ioremap                  */
#include <asm/arch/hardware.h>	/* atmel RM9200           	*/      
#include <asm/arch/pio.h>




#undef	DEBUG
//#define	DEBUG		1

#ifdef	DEBUG
# define debugk(fmt,args...)	printk(fmt ,##args)
#else
# define debugk(fmt,args...)
#endif

/*
 * Deal with CONFIG_MODVERSIONS
 */
#if CONFIG_MODVERSIONS==1
/* # define MODVERSIONS */
# include <linux/modversions.h>
#endif


MODULE_LICENSE("GPL");


#ifndef KERNEL_VERSION
# define KERNEL_VERSION(a,b,c)	((a)*65536+(b)*256+(c))
#endif


#define SUCCESS 	0

#define TIMER_INTERVAL  50        /* timer interval ms */

/* see ATMEL RM9200 datasheet */
#define AT91C_BASE_KBS		0x808c0018     	/* scan output base address */
#define AT91C_BASE_KR		0x80840018	/* scan input  base address */
#define BASE_MEM_LEN            0x04     	/* address length for ioremap */

/*
 * Prototypes
 */
static int __init  scankey_init (void );


struct timer_list scan_timer;

int status;  /*0: Null   1: press  2:wait unpress*/



static void  *kbs_base;
static void  *kr_base;

struct key_map {
	unsigned char scan_code;
	unsigned char *disp_str;
	};

struct key_map hm_5x4_keymap[] = {  
	{ 0x0e,	"1" },
	{ 0x1e,	"2" },
	{ 0x2e, "3" },
	{ 0x3e, "F1" },
	{ 0x4e, "F2" },
	{ 0x0d,	"4" },
	{ 0x1d,	"5" },
	{ 0x2d, "6" },
	{ 0x3d, "F3" },
	{ 0x4d, "CR" },
	{ 0x0b,	"7" },
	{ 0x1b, "8" },
	{ 0x2b, "9" },
	{ 0x3b, "UP" },
	{ 0x4b, "DOWN" },
	{ 0x07, "*" },
	{ 0x17, "0" },
	{ 0x27, "#" },
	{ 0x37, "LEFT" },
	{ 0x47, "RIGHT" }
     };

void trans_key (unsigned char scan_code)
{ 
   int i;

	for (i=0; i < sizeof(hm_5x4_keymap)/sizeof(struct key_map); i++) {
	     if (scan_code == hm_5x4_keymap[i].scan_code)
		printk("Pressed key is  %s \n",hm_5x4_keymap[i].disp_str);
	}  
	  
}

void hm_scankey(void* data)
{
   unsigned char i,k;
   unsigned char scan_code;
   
	switch (status) 
	{
	   case 0:   
		writeb(0xe0,  kbs_base);
		if ((readb(kr_base) & 0x0f) != 0x0f)
		    status = 1;
		break;
	   case 1:             
	        writeb (0xe0, kbs_base);
		if ((readb(kr_base) & 0x0f) == 0x0f)
		    status = 0;
		for (i=0; i<5; i++){  
		    writeb(~(1<<i), kbs_base);
		    k = readb(kr_base) & 0x0f;
		    if (k!=0x0f) {
		    	scan_code = (k & 0x0f) | (i<<4);
		    	debugk("Key Scan = %02x \n", scan_code);
			trans_key(scan_code);
		    	status = 2;
			writeb(0xff, kbs_base);
		    	break;
		    }
		}
		break;
	   case 2:
	   	writeb(0xe0, kbs_base);
	   	k = readb(kr_base) & 0x0f;
	   	if (k == 0x0f)
	   	   status = 0;
	   	break;
	}
	

	init_timer(&scan_timer);
	scan_timer.function = (void (*)(unsigned long))hm_scankey;
        //scan_timer.data     = (unsigned long)&_data;
        scan_timer.expires  = TIMER_INTERVAL * HZ /1000;

	mod_timer(&scan_timer, jiffies + TIMER_INTERVAL * HZ/1000);
	
}


/*
 * Initialize the driver - Register the character device
 */
static int __init scankey_init(void)
{


	/* get the remmapped port  base address register */
	kbs_base = ioremap_nocache(AT91C_BASE_KBS, BASE_MEM_LEN);
        kr_base = ioremap_nocache(AT91C_BASE_KR, BASE_MEM_LEN);   
	
	status = 0;
	
	init_timer(&scan_timer);
	scan_timer.function = (void(*)(unsigned long))hm_scankey;
//	runled_timer.data     = (unsigned long)&runled_data;
	scan_timer.expires  = jiffies + TIMER_INTERVAL * HZ /1000;
	add_timer(&scan_timer);

	return 0;
}

/******************************
 **** Module Declarations *****
 **************************** */

#ifdef MODULE

/*
 * Cleanup - unregister 
 */
static void __exit cleanup_scankey_module (void)
{


	iounmap (kbs_base);
	iounmap (kr_base);
	
	del_timer(&scan_timer);	
	return;
}

module_init(scankey_init);
module_exit(cleanup_scankey_module);

MODULE_AUTHOR("Himai");
MODULE_DESCRIPTION("scan key for HM901ESP");

#endif	/* MODULE */