kobox -- key_tasklet.c -v1

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将key.c中的timer机制、key_wq.c中的workqueue机制改成tasklet机制，完成中断的下半部

需要特别注意：tasklet中不可休眠，其上下文是中断，而workqueue是可以休眠的，wq的上下文是内核线程

所以这里并没有去除抖动，如果需要延时去抖动，timer或者workqueue更合适

如果需要休眠，就不能选择tasklet

#include "key.h"


#define S3C_ADDR_BASE	0xF6000000
#define S3C_ADDR(x)	(S3C_ADDR_BASE + (x))
#define S3C2410_PA_UART		(0x50000000)
#define S3C2410_PA_GPIO		(0x56000000)
#define S3C_VA_UART	S3C_ADDR(0x01000000)	/* UART */
#define S3C24XX_PA_UART		S3C2410_PA_UART
#define S3C24XX_VA_UART		S3C_VA_UART
#define S3C24XX_PA_GPIO		S3C2410_PA_GPIO
#define S3C24XX_VA_GPIO		((S3C24XX_PA_GPIO - S3C24XX_PA_UART) + S3C24XX_VA_UART)


#define S3C2410_GPIOREG(x) ((x) + S3C24XX_VA_GPIO)


#define S3C2410_GPBCON	   S3C2410_GPIOREG(0x10)
#define S3C2410_GPBDAT	   S3C2410_GPIOREG(0x14)
#define S3C2410_GPBUP	   S3C2410_GPIOREG(0x18)


#define S3C2410_GPFCON	   S3C2410_GPIOREG(0x50)
#define S3C2410_GPFDAT	   S3C2410_GPIOREG(0x54)
#define S3C2410_GPFUP	   S3C2410_GPIOREG(0x58)


#define S3C2410_EXTINT0	   S3C2410_GPIOREG(0x88)
#define S3C2410_EXTINT1	   S3C2410_GPIOREG(0x8C)
#define S3C2410_EXTINT2	   S3C2410_GPIOREG(0x90)


#define S3C2410_CPUIRQ_OFFSET	 (16)
#define S3C2410_IRQ(x) ((x) + S3C2410_CPUIRQ_OFFSET)
/* main cpu interrupts */
#define IRQ_EINT0      S3C2410_IRQ(0)	    /* 16 */
#define IRQ_EINT1      S3C2410_IRQ(1)		/* 17 */
#define IRQ_EINT2      S3C2410_IRQ(2)		/* 18 */
#define IRQ_EINT4t7    S3C2410_IRQ(4)	    /* 20 */
#define IRQ_EINT4      S3C2410_IRQ(36)	   /* 52 */


#define IRQF_DISABLED		0x00000020
#define IRQF_SHARED		0x00000080
#define IRQF_PROBE_SHARED	0x00000100
#define __IRQF_TIMER		0x00000200
#define IRQF_PERCPU		0x00000400
#define IRQF_NOBALANCING	0x00000800
#define IRQF_IRQPOLL		0x00001000
#define IRQF_ONESHOT		0x00002000
#define IRQF_NO_SUSPEND	0x00004000
#define IRQF_FORCE_RESUME	0x00008000
#define IRQF_NO_THREAD		0x00010000
#define IRQF_EARLY_RESUME	0x00020000


typedef struct gpioRes
{
	int irqNum;		/* 中断号 */
	unsigned int ctrlReg;	/* 控制寄存器,用于设置复用为GPIO */
	unsigned int ctrlBit; 	/* 控制寄存器的哪一位，用于复用为GPIO */
	unsigned int trigReg;	/* 中断方式寄存器，设置中断的触发方式 */
	unsigned int trigBit;	/* 中断方式寄存器哪一位，设置中断的触发方式 */
	unsigned int irqFlag;	/* 共享还是不共享，注册中断的flag */
	char irqName[32];		/* 中断名称 */
	unsigned int gpfPin;	/* GPF的第几个pin */
	char Reserved[10];		/* 保留 */
}gpioRes;


unsigned int pressCnt[4] = {0, 0, 0, 0};


#define ARRAY_SIZE(arr) (sizeof(arr)/sizeof((arr)[0]))


static int kobox_key_open(struct inode *inode, struct file *file)
{
	return 0;
}


static int kobox_key_release(struct inode *inode, struct file *file)
{
	return 0;
}


static long kobox_key_ioctl(struct file *file, unsigned int cmd,
			   unsigned long arg)
{
	return 0;
}


static int kobox_key_read(struct file *file, char __user *buff, size_t count, loff_t *pos)
{
	printk("Enter [%s][%d]\n", __FUNCTION__,__LINE__);
	copy_to_user(buff, &pressCnt[0], sizeof(pressCnt));
	
	return 0;
}


/*
GPF相关寄存器:


GPFCON 0x56000050 R/W Configures the pins of port F 0x0
GPFDAT 0x56000054 R/W The data register for port F Undef.
GPFUP  0x56000058 R/W Pull-up disable register for port F 0x000


K1: GPF1 -EINT1: GPF1 [3:2] 00 = Input	01 = Output 10 = EINT[1]  11 = Reserved
K2: GPF4 -EINT4: GPF4 [9:8] 00 = Input	01 = Output 10 = EINT[4]  11 = Reserved
K3: GPF2 -EINT2: GPF2 [5:4] 00 = Input	01 = Output 10 = EINT2]  11 = Reserved
K4: GPF0 -EINT0: GPF0 [1:0] 00 = Input	01 = Output 10 = EINT[0]  11 = Reserved
*/




gpioRes key_gpio_res[4] =
{
	{IRQ_EINT1, S3C2410_GPFCON, 2, S3C2410_EXTINT0, 5, NULL, "key1", 1},	/* key1 */
	{IRQ_EINT4, S3C2410_GPFCON, 8, S3C2410_EXTINT0, 17, IRQF_SHARED, "key2", 4},	/* key2 */
	{IRQ_EINT2, S3C2410_GPFCON, 4, S3C2410_EXTINT0, 9, NULL, "key3", 2},	/* key3 */
	{IRQ_EINT0, S3C2410_GPFCON, 0, S3C2410_EXTINT0, 1, NULL, "key4", 0},	/* key4 */
};


#define KEY_TIMER_DELAY1    (HZ/50)             //按键按下去抖延时20毫秒       
#define KEY_TIMER_DELAY2    (HZ/10)             //按键抬起去抖延时100毫秒
#define KEY_COUNT 4


struct tasklet_struct gpio_key_tasklet;
static void gpio_key_tasklet_handler(unsigned long data);




static void set_gpio_as_eint(void)
{
	int i;
	unsigned uiVal = 0;


	for(i=0; i<	ARRAY_SIZE(key_gpio_res); i++)
	{
		uiVal = readl(key_gpio_res[i].ctrlReg);
		uiVal &= ~(0x01 << key_gpio_res[i].ctrlBit);
		uiVal |= (0x01 << (key_gpio_res[i].ctrlBit + 1));
		writel(uiVal, key_gpio_res[i].ctrlReg);
	}


	return;
}


static void set_gpio_as_gpio(void)
{
	int i;
	unsigned uiVal = 0;


	for(i=0; i<	ARRAY_SIZE(key_gpio_res); i++)
	{
		uiVal = readl(key_gpio_res[i].ctrlReg);
		uiVal &= ~(0x01 << key_gpio_res[i].ctrlBit);
		uiVal &= ~(0x01 << (key_gpio_res[i].ctrlBit + 1));
		writel(uiVal, key_gpio_res[i].ctrlReg);
	}


	return;
}




static irqreturn_t kobox_gpio_irq_handle(int irq, void *dev_id)
{
	int key;


	disable_irq_nosync(irq);




	printk("irq = %d\n", irq);


	if(dev_id)
		printk("dev_id:%s\n", dev_id);


	switch(irq)
	{
		case IRQ_EINT1:
			key = 0;
			break;
		case IRQ_EINT4:
			key = 1;
			break;
		case IRQ_EINT2:
			key = 2;
			break;
		case IRQ_EINT0:
			key = 3;
			break;
		default:
			printk("invalid irq:%d\n", irq);
 			return IRQ_HANDLED;
 	}


	/* 去抖:延时100ms后，在buttons_timer中读取按键状态，如果还是按下的，就说明是被正常按下的
		使用timer是一种方式，后面再采用工作队列、tasklet中的方式来处理	*/
	tasklet_schedule(&gpio_key_tasklet);


	enable_irq(irq);
	
	return IRQ_RETVAL(IRQ_HANDLED);
}


/*
GPF相关寄存器:


GPFCON 0x56000050 R/W Configures the pins of port F 0x0
GPFDAT 0x56000054 R/W The data register for port F Undef.
GPFUP  0x56000058 R/W Pull-up disable register for port F 0x000


K1: GPF1 -EINT1: GPF1 [3:2] 00 = Input	01 = Output 10 = EINT[1]  11 = Reserved
K2: GPF4 -EINT4: GPF4 [9:8] 00 = Input	01 = Output 10 = EINT[4]  11 = Reserved
K3: GPF2 -EINT2: GPF2 [5:4] 00 = Input	01 = Output 10 = EINT2]  11 = Reserved
K4: GPF0 -EINT0: GPF0 [1:0] 00 = Input	01 = Output 10 = EINT[0]  11 = Reserved
*/
/* 该函数返回0表示按键被按下，返回非0表示没有再被按下，认为这是电平毛刺导致的，是噪声信号
	所以，该函数返回0，表示有按键被按下，返回非0表示是抖动	*/
static int get_gpio_portf_value(unsigned int pin)
{
	int ret;
	unsigned int uiVal = 0;


	printk("I AM @ [%s][%d], pin:%d\n", __FUNCTION__,__LINE__, pin);	


	uiVal = readl(S3C2410_GPFDAT);
	ret = (0x1 << pin) & uiVal;


	printk("I AM @ [%s][%d], ret:%d\n", __FUNCTION__,__LINE__, ret);	


	return ret;
}


static void gpio_key_tasklet_handler(unsigned long data)
{
	int i = 0;
	int ret;
	unsigned int pin;


	/* 中断后100ms才会导致，执行该函数 */
	printk("i am at [%s][%d]\n", __FUNCTION__, __LINE__);


//	msleep(100);


	/* 将引脚由EINTX设置会GPIO */
	set_gpio_as_gpio();


	for(i=0; i<ARRAY_SIZE(key_gpio_res); i++)
	{
		pin = key_gpio_res[i].gpfPin;


		/* 读取对应引脚GPIO的值，返回0表示按键真正被按下，返回1表示抖动 */
		ret = get_gpio_portf_value(pin);
		if(0 == ret)
		{
			pressCnt[i]++;
			printk("key0 pressed: pressCnt[%d]:%d\n", i, pressCnt[i]);
		}
	}
	/* 将引脚设置回EINTX */
	set_gpio_as_eint();
	
	return;
}


static int request_irq_for_gpio(void)
{
	int i;
	int ret;
	unsigned uiVal;
	int nouse;


	for(i=0; i<ARRAY_SIZE(key_gpio_res);i++)
	{
		/* 设置中断触发方式:下降沿有效，触发中断，以便根据GPIO的值来判断是否仍在按下 */
		uiVal = readl(key_gpio_res[i].trigReg);
		uiVal |= (0x1 << (key_gpio_res[i].trigBit));
		uiVal &= ~(0x1 << (key_gpio_res[i].trigBit + 1));
		writel(uiVal, key_gpio_res[i].trigReg);


		/* 注册中断 */
		ret = request_irq(key_gpio_res[i].irqNum, 
						   kobox_gpio_irq_handle,
						   key_gpio_res[i].irqFlag,
						   key_gpio_res[i].irqName,
						   (void *)key_gpio_res[i].irqName);
		if(ret)
			printk("[func:%s][line:%d] request_irq failed, ret:%d!\n", __FUNCTION__,__LINE__,ret);
		else
			printk("[func:%s][line:%d] request_irq ok, irq:%d!\n", __FUNCTION__,__LINE__, key_gpio_res[i].irqNum);	
		
		tasklet_init(&gpio_key_tasklet, gpio_key_tasklet_handler, NULL);			
	}


	return 0;
}


struct file_operations kobox_key_operations = {
	.owner          = THIS_MODULE,
	.open           = kobox_key_open,
	.read 			= kobox_key_read,
	.release        = kobox_key_release,
	.unlocked_ioctl = kobox_key_ioctl,
};


//GPB0
int major;
int minor;
struct cdev cdev;
struct class *kobox_key_class;
struct device *pstdev = NULL;
#define GPIO_KEY_NAME "kobox_key"


int __init key_drv_init(void)
{
	int error;
	dev_t dev;


	printk("#####enter key_drv_init!\n");


	major = register_chrdev(0, GPIO_KEY_NAME, &kobox_key_operations);
	if (major < 0)
	{
		printk(" can't register major number\n");
		return major;
	}


	/* create class */
	kobox_key_class = class_create(THIS_MODULE, GPIO_KEY_NAME);
	if(IS_ERR(kobox_key_class))
	{
		printk("class_create failed!\n");
		goto fail;
	}


	/* create /dev/kobox_gpio */
	pstdev = device_create(kobox_key_class, NULL, MKDEV(major, 0), NULL, GPIO_KEY_NAME);
	if(!pstdev)
	{
		printk("device_create failed!\n");
		goto fail1;
	}


	/* set gpf0/1/2/4 as extern interrupt pins */
	set_gpio_as_eint();


	request_irq_for_gpio();


	printk("#####key_drv_init ok!\n");
	
	return 0;
fail1:
	class_destroy(kobox_key_class);
fail:
	unregister_chrdev(major, GPIO_KEY_NAME);
	return -1;
}


void __exit key_drv_exit(void)
{
	printk("exit gpio drv!\n");	


	device_destroy(kobox_key_class, MKDEV(major, 0));
	class_destroy(kobox_key_class);
	unregister_chrdev(major, GPIO_KEY_NAME);


	return;
}


module_init(key_drv_init);
module_exit(key_drv_exit);
MODULE_LICENSE("GPL");

kobox -- key_tasklet.c -v1

标签：des   style   blog   color   io   os   使用   ar   for   

原文地址：http://blog.csdn.net/xiangpingli/article/details/40118019