在系统中增加一个可唤醒中断--简单实例

在系统休眠的时候3G来电或者短信需要唤醒系统，使系统resume。从3G模块手册看到有WAKE#脚，当收到来电或者SMS时这个脚会有0.5S的拉低，就是cp_wakeup_ap，用这个脚做唤醒脚。查看AP的datasheet，挑选一个带有EINT功能的GPIO脚做接收此中断的脚，这里选GPX3(1)。开始写驱动来处理这个事件。

kernel\arch\arm\mach-exynos\setup-mu609.c

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/skbuff.h>

#include <plat/devs.h>
#include <plat/sdhci.h>
#include <plat/gpio-cfg.h>
#include <mach/regs-gpio.h>
#include <mach/gpio.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/module.h>

static irqreturn_t host_wake_isr(int irq, void *dev)
{
/*
do something when interrupt happen
*/
return IRQ_HANDLED;
}

static int mu609_probe(struct platform_device *pdev)
{
int irq;
int ret;

printk("%s: start\n", __FUNCTION__);

s3c_gpio_cfgpin(EXYNOS5410_GPX3(1), S3C_GPIO_INPUT); //stone++ for mu609
s3c_gpio_setpull(EXYNOS5410_GPX3(1), S3C_GPIO_PULL_UP); //stone++ for mu609

irq = IRQ_EINT(25);
ret = request_irq(irq, host_wake_isr, IRQF_TRIGGER_FALLING,
"3g mu609_wake", NULL);
if (ret) {
pr_err("[3G] Request_host wake irq failed.\n");
return ret;
}

ret = irq_set_irq_wake(irq, 1);
if (ret) {
pr_err("[3G] Set_irq_wake failed.\n");
return ret;
}

return ret;
}

static int mu609_remove(struct platform_device *pdev)
{
return 0;
}

static struct platform_driver mu609_driver = {
.probe = mu609_probe,
.remove = mu609_remove,
.driver = {
.name = "mu609_3g",
.owner = THIS_MODULE,
},
};

static struct platform_device mu609_device = {
.name	= "mu609_3g",
.id		= -1,
};

static int __init mu609_init(void)
{
int ret;

ret = platform_driver_register(&mu609_driver);
if(!ret){
ret =  platform_device_register(&mu609_device);
if (ret)
platform_driver_unregister(&mu609_driver);
}
return ret;
}
late_initcall(mu609_init);

kernel\arch\arm\mach-exynos\Makefile

obj-$(CONFIG_EXYNOS_DEV_MU609)  += setup-mu609.o

kernel\arch\arm\mach-exynos\Kconfig

config EXYNOS_DEV_MU609
bool "3G module MU609"
default y
help
HuaWei mu609.

cat /proc/interrupt可以查看中断有没有开始工作