中断的下半部分之二tasklet

在linux中使用tasklet
软硬件环境:linux-2.6.36/s3c2440

tasklet是通过软中断实现的，所以它本身也是软中断。

test.c

#include <linux/module.h>
#include <linux/init.h>

#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/delay.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("zhanglong");

struct tasklet_struct my_tasklet;

void tasklet_action(unsigned long arg)
{
    printk("tasklet handle. arg = %ld\n", arg);    
}

static irqreturn_t irq_handle(int irq, void *dev_id)
{
    tasklet_schedule(&my_tasklet);　　　　//再中断处理函数中调度tasklet
    printk("------irq handle. dev_id = %d\n", (int)dev_id);
    return IRQ_HANDLED;
}

int test_init(void)
{
    int ret = 0;

    tasklet_init(&my_tasklet, tasklet_action, 789);

    set_irq_type(IRQ_EINT0, IRQ_TYPE_EDGE_RISING);
    ret = request_irq(IRQ_EINT0, irq_handle, 0, "my irq", (void *)123);
    if (ret) {    
        printk("request irq failed.\n");
        return -EBUSY;
    }

    return 0;
}

void test_exit(void)
{
    free_irq(IRQ_EINT0, (void *)123);
}

module_init(test_init);
module_exit(test_exit);

Makefile

#KERNEL    = /home/zl/my2440-2.6.13
KERNEL    = /media/STUDY/linux/kernel/my2440-2.6.36
#KERNEL    = /lib/modules/$(shell uname -r)/build

default:
    make -C $(KERNEL) M=$(shell pwd) modules

clean:
    make -C $(KERNEL) M=$(shell pwd) modules clean

modules_install:
    make -C $(KERNEL) M=$(shell pwd) modules_install INSTALL_MOD_PATH=/home/zl/s3c2440_nfs
    depmod -a -b /home/zl/s3c2440_nfs 2.6.13-ZL2440


obj-m    += test.o

make后插入生成的test.ko模块。按下GPF0所在的按键，终端会有输出：
[root@zhanglong mytasklet]# ------irq handle. dev_id = 123
tasklet handle. arg = 789
------irq handle. dev_id = 123
tasklet handle. arg = 789
------irq handle. dev_id = 123
tasklet handle. arg = 789
……