button.c

《linux驱动程序设计从入门到精通》一书中所有的程序代码含驱动和相应的应用程序

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2007, 2010 fengGuojin([e-mail])
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/arch-s3c2410/irqs.h>
#include <asm/signal.h>
#include <asm/hardware.h>
#include <asm/uaccess.h>
#include <asm/arch/regs-gpio.h>
#include <asm/arch/regs-irq.h>
#include <asm/dma.h>

MODULE_AUTHOR("FGJ");
MODULE_DESCRIPTION("buttons driver");
MODULE_LICENSE("GPL");

#define DEBUG_DRIVER 1
static unsigned char simplekey_keycode[0x08] = {
	[0]	 = KEY_1,
	[1]	 = KEY_2,
	[2]	 = KEY_3,
	[3]	 = KEY_4,
	[4]	 = KEY_5,
	[5]	 = KEY_6,
	[6]	 = KEY_7,
	[7]	 = KEY_8,
};

static int irqArray[4]=
{
	IRQ_EINT0,
	IRQ_EINT2,
	IRQ_EINT11,
	IRQ_EINT19
};

static struct input_dev simplekey_dev;

static char *simplekey_name = "simplekey";
static char *simplekey_phys = "input0";

struct timer_list polling_timer;
static unsigned long  polling_jffs=0;
void polling_handler(unsigned long data)
{
        int code=-1;

	writel(readl(S3C2410_SRCPND)&0xffffffda,S3C2410_SRCPND);//clear srcpnd 0 2 11 19
	mdelay(1);
	//扫描按键表，根据中断号，找出所按下的按键。
	writel(readl(S3C2410_GPBDAT)|0x80,S3C2410_GPBDAT);//set GPB76 to 10
        writel(readl(S3C2410_GPBDAT)&0xffffffBf,S3C2410_GPBDAT);//...

	if((readl(S3C2410_GPFDAT)&(1<< 0)) == 0 )
	{
	    code=0;
	    goto IRQ_OUT;
	}
	else if( (readl(S3C2410_GPFDAT)&(1<< 2)) == 0 )
	{
	    code=2;
	    goto IRQ_OUT;
	}
	else if( (readl(S3C2410_GPGDAT)&(1<< 3)) ==0 )
	{
	    code=4;
	    goto IRQ_OUT;
	}
	else if( (readl(S3C2410_GPGDAT)&(1<<11)) == 0 )
	{
	    code=6;
	    goto IRQ_OUT;
	}

	writel(readl(S3C2410_SRCPND)&0xffffffda,S3C2410_SRCPND);//clear srcpnd 0 2 11 19
	mdelay(1);
	writel(readl(S3C2410_GPBDAT)|0x40,S3C2410_GPBDAT);//set GPB76 to 01
	writel(readl(S3C2410_GPBDAT)&0xffffff7f,S3C2410_GPBDAT);//...

        if((readl(S3C2410_GPFDAT)&(1<< 0)) == 0 )
	{
	    code=1;
	    goto IRQ_OUT;
	}
	else if( (readl(S3C2410_GPFDAT)&(1<< 2)) == 0 )
	{
	    code=3;
	    goto IRQ_OUT;
	}
	else if( (readl(S3C2410_GPGDAT)&(1<< 3)) ==0 )
	{
	    code=5;
	    goto IRQ_OUT;
	}
	else if( (readl(S3C2410_GPGDAT)&(1<<11)) == 0 )
	{
	    code=7;
	    goto IRQ_OUT;
	}

IRQ_OUT:
	enable_irq(IRQ_EINT0);
	enable_irq(IRQ_EINT2);
	enable_irq(IRQ_EINT11);
	enable_irq(IRQ_EINT19);

	if(code>=0)
	{
		//避免中断连续出现
		if((jiffies-polling_jffs)>100)
		{
			polling_jffs=jiffies;
			input_report_key(&simplekey_dev, simplekey_keycode[code], 1);
			input_report_key(&simplekey_dev, simplekey_keycode[code], 0);
			input_sync(&simplekey_dev);
#if DEBUG_DRIVER
			printk("key %d\n",code) ;
#endif
		}
	}

	writel(readl(S3C2410_GPBDAT)&0xffffff3f,S3C2410_GPBDAT);
}

static irqreturn_t simplekey_interrupt(int irq, void *dummy, struct pt_regs *fp)
{
	disable_irq(IRQ_EINT0);
	disable_irq(IRQ_EINT2);
	disable_irq(IRQ_EINT11);
	disable_irq(IRQ_EINT19);

	polling_timer.expires = jiffies + HZ/5;
	add_timer(&polling_timer);

	return IRQ_HANDLED;
}

void initButton(void)
{
	writel((readl(S3C2410_GPGCON)&(~((3<<22)|(3<<6))))|((2<<22)|(2<<6)),S3C2410_GPGCON);		//GPG11,3 set EINT
	writel((readl(S3C2410_GPFCON)&(~((3<<4)|(3<<0))))|((2<<4)|(2<<0)),S3C2410_GPFCON) ;		//GPF2,0 set EINT

	writel((readl(S3C2410_EXTINT0)&(~(7|(7<<8)))),S3C2410_EXTINT0);
	writel((readl(S3C2410_EXTINT0)|(0|(0<<8))),S3C2410_EXTINT0);	//set eint0,2 falling edge int
	writel((readl(S3C2410_EXTINT1)&(~(7<<12))),S3C2410_EXTINT1);
	writel((readl(S3C2410_EXTINT1)|(0<<12)),S3C2410_EXTINT1);	//set eint11 falling edge int
	writel((readl(S3C2410_EXTINT2)&(~(0xf<<12))),S3C2410_EXTINT2);
	writel((readl(S3C2410_EXTINT2)|(0<<12)),S3C2410_EXTINT2);	//set eint19 falling edge int

	writel((readl(S3C2410_GPBCON)&(~((3<<12)|(3<<14)))),S3C2410_GPBCON);
	writel((readl(S3C2410_GPBCON)|(((1<<12)|(1<<14)))),S3C2410_GPBCON);
	writel((readl(S3C2410_GPBUP)|(3<<6)),S3C2410_GPBUP);
	writel((readl(S3C2410_GPBDAT)&(~(3<<6))),S3C2410_GPBDAT);

	writel((readl(S3C2410_EINTPEND)|((1<<11)|(1<<19))),S3C2410_EINTPEND);		//clear eint 11,19
	writel((readl(S3C2410_EINTMASK)&(~((1<<11)|(1<<19)))),S3C2410_EINTMASK);	//enable eint11,19*/
}

static int __init simplekey_init(void)
{
	int i;
	
	initButton();
	polling_jffs=jiffies;
	for (i = 0; i <4; i++) {
		if (request_irq(irqArray[i], &simplekey_interrupt, SA_INTERRUPT, "simplekey", NULL)) {
			printk("request button irq failed!\n");
			return -1;
		}		
	}

	init_input_dev(&simplekey_dev);

	simplekey_dev.evbit[0] = BIT(EV_KEY);// | BIT(EV_REP);
	simplekey_dev.keycode = simplekey_keycode;
	simplekey_dev.keycodesize = sizeof(unsigned char);
	simplekey_dev.keycodemax = ARRAY_SIZE(simplekey_keycode);
	//下面的语句必不可少
	for (i = 0; i < 0x78; i++)
		if (simplekey_keycode[i])
			set_bit(simplekey_keycode[i], simplekey_dev.keybit);

	simplekey_dev.name = simplekey_name;
	simplekey_dev.phys = simplekey_phys;
	simplekey_dev.id.bustype = BUS_AMIGA;
	simplekey_dev.id.vendor = 0x0001;
	simplekey_dev.id.product = 0x0001;
	simplekey_dev.id.version = 0x0100;

	input_register_device(&simplekey_dev);
#if DEBUG_DRIVER
	printk(KERN_ERR "initialize button ok!");
#endif
	init_timer(&polling_timer);
	polling_timer.data = (unsigned long)0;
	polling_timer.function = polling_handler;
	return 0;
}

static void __exit simplekey_exit(void)
{
	int i;
	for (i = 0; i <4; i++) {
		free_irq(irqArray[i],simplekey_interrupt);
	}
	input_unregister_device(&simplekey_dev);
}

module_init(simplekey_init);
module_exit(simplekey_exit);