s3c24xx_buttons.c

2440 下的5*5按键驱动程序.请参看具体代码内容.

/*按键驱动
* date:Dec.02,2008
* author: daihj07@thu
* v1.0
*/

#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/interrupt.h>
#include <asm/uaccess.h>
#include <asm/arch/regs-gpio.h>
#include <asm/hardware.h>
#include <asm/io.h>	//for ioremap
#include <linux/delay.h>

#define DEVICE_NAME     "buttons"   /* 加载模式后，执行”cat /proc/devices”命令看到的设备名称 */
#define BUTTON_MAJOR    232         /* 主设备号 */

struct button_irq_desc {
    int irq;
    unsigned long flags;
    char *name;
};

/* 用来指定按键所用的外部中断引脚及中断触发方式, 名字 */
static struct button_irq_desc button_irqs [] = {
    {IRQ_EINT1, IRQF_TRIGGER_FALLING, "KEYINT1"}, /* K1 */
    {IRQ_EINT2, IRQF_TRIGGER_FALLING, "KEYINT2"}, /* K2 */
    {IRQ_EINT3,  IRQF_TRIGGER_FALLING, "KEYINT3"}, /* K3 */
    {IRQ_EINT4,  IRQF_TRIGGER_FALLING, "KEYINT4"}, /* K4 */
    {IRQ_EINT5,  IRQF_TRIGGER_FALLING, "KEYINT5"}, /* K5 */
};

/* 用来指定key 所用的GPIO引脚 */
static unsigned long key_output_table [] = {
    S3C2410_GPB6,
    S3C2410_GPB7,
    S3C2410_GPB8,
    S3C2410_GPB9,
    S3C2410_GPB10,
};
/* 用来指定GPIO引脚的功能：输出 */
static unsigned int key_output_cfg_table [] = {
    S3C2410_GPB6_OUTP,
    S3C2410_GPB7_OUTP,
    S3C2410_GPB8_OUTP,
    S3C2410_GPB9_OUTP,
    S3C2410_GPB10_OUTP,
};
static unsigned long key_input_table [] = {
	S3C2410_GPF1,
	S3C2410_GPF2,
	S3C2410_GPF3,
	S3C2410_GPF4,
	S3C2410_GPF5,
};

/* 按键被按下的次数(准确地说，是发生中断的次数) */
static volatile int press_cnt [] = {0, 0, 0, 0, 0};

/* 等待队列: 
 * 当没有按键被按下时，如果有进程调用s3c24xx_buttons_read函数，
 * 它将休眠
 */
static DECLARE_WAIT_QUEUE_HEAD(button_waitq);

/* 中断事件标志, 中断服务程序将它置1，s3c24xx_buttons_read将它清0 */
static volatile int ev_press = 0;

/* GPB6-10 output, low
*	GPF1-5, interrupt,  上拉
 */
static int s3c24xx_key_iocfg(void)
{
    int i;
    for (i = 0; i < sizeof(key_output_table)/sizeof(key_output_table[0]);i++) {
        // 设置GPIO引脚的功能：本驱动中GPB6-10 引脚设为输出功能,low
        s3c2410_gpio_cfgpin(key_output_table[i], key_output_cfg_table[i]);
		s3c2410_gpio_setpin(key_output_table[i], 0);	//	output low
    }
	/*
		rGPFCON = (rGPFCON & ~(0x3ff<<2)) | (0x2aa<<2); 	//GPF 1-5 EINT
	rGPFUP = rGPFUP&(~(0x1f<<1));
	rEXTINT0 = (rEXTINT0& ~(0xfffff<<4)) | (0x00000<<4); 	//EXTINT 1-5 low level triggered
	先只确定内部上拉；
	*/
	for(i = 0;  i < sizeof(key_input_table)/sizeof(key_input_table[0]);i++) {
		s3c2410_gpio_pullup(key_input_table[i], 0);
		}
    return 0;
}

/******************************************************************************
5*5 键盘

五个输入引脚: 
GPF5 EINT5	EINT5/GPF5  按键	CN1-91	EINT
GPF4 EINT4	EINT4/GPF4  按键	CN1-90	EINT
GPF3 EINT3	EINT3/GPF3  按键	CN1-89	EINT
GPF2 EINT2	EINT2/GPF2  按键	CN1-88	EINT
GPF1 EINT1	EINT1/GPF1 按键	CN1-87	EINT

GPB10 nXDREQ0	GPB10	CN2-91	按键
GPB9 nXDACK0	GPB9	CN2-90	按键
GPB8 nXDREQ1	GPB8:LED4:LDMD3:KEY8	CN2-89	按键 输出
GPB7 nXDACK1	GPB7:LED3:LDMD2:KEY7	CN2-88	按键 输出
GPB6 nXBREQ	GPB6:LED2:LDMD1:KEY6	CN2-87	按键 输出
GPB5 nXBACK	GPB5:LED1:LCM_D0	CN2-86	
******************************************************************************/
#if 0
static int  T3h_key_Scan( int irq )
{
	int i;
	int dat;
	int j;
	int nirq;
	unsigned long GPBDAT,GPFDAT,GPFCON;
	nirq=sizeof(button_irqs)/sizeof(button_irqs[0]);
	printk("key scan started!,nirq= %d",nirq);
/*读取GPFCON寄存器的值
*#define rGPFCON    (*(volatile unsigned *)0x56000050)	//Port F control
*/
	GPBDAT=(unsigned long)ioremap(0x56000014,4);
	GPFDAT=(unsigned long)ioremap(0x56000054,4);
	GPFCON=(unsigned long)ioremap(0x56000050,4);
	printk("GPFCON = %x",GPFCON);
	printk("irq=%d in key scan", irq);
//	delay(900);
		for(j=0;j<nirq;j++){
			if(irq==button_irqs[j].irq){
				for(i=0;i<ncol;i++){
					(*(volatile unsigned long *)GPBDAT) = ((*(volatile unsigned long *)GPBDAT) & ~(0x1f<<6)) | (~((1<<i)& 0x1f)<<6);  // GPB 6-10	clear first and set, low to ready, clear the corresponding bit, set others
					dat= (*(volatile unsigned long *)GPFDAT)>>1;
					if(((dat>>j)&1)==0){
						printk("row=%d,	col=%d\n",i,j);
						return i+1;
						}
					}
				}
			}
	return -1;
}
#endif
static int  T3h_key_Scan( int irq )
{
	int i;
	int dat;
	int j;
	int nirq,ncol;
	int ret=-1;
	nirq=sizeof(button_irqs)/sizeof(button_irqs[0]);
	ncol=sizeof(key_output_table)/sizeof(key_output_table[0]);
//	printk("key scan started!,nirq= %d, ncol= %d,irq=%d in key scan\n", nirq ,ncol,irq);
	for(i=0;i<ncol;i++){
		s3c2410_gpio_setpin(key_output_table[i], 1);	//	output high
		}
	for(j=0;j<nirq;j++){
		if(irq==button_irqs[j].irq){
			for(i=0;i<ncol;i++){
				s3c2410_gpio_setpin(key_output_table[i], 0);	//	output low
				dat= s3c2410_gpio_getpin(key_input_table[j]);
				if(dat==0){
//					printk("row(j)=%d,	col(i)=%d\n",j,i);
					ret= i+1;
					break;
					}
				s3c2410_gpio_setpin(key_output_table[i], 1);	//	output high
				}			
			break;
			}
		}
	for(i=0;i<ncol;i++){
	s3c2410_gpio_setpin(key_output_table[i], 0);	//	output low
	}
	return ret;
}
static irqreturn_t buttons_interrupt(int irq, void *dev_id)
{
    volatile int *press_cnt = (volatile int *)dev_id;	//device_id 如何传递的澹