下面是矩陣按鍵數組的定義，數組元素的信息（一個按鍵信息）按照0行0列，0行1列，…，3行2列，3行3列的順序逐行排列。

staticst_key_info_matrixkey_info_matrix[MAX_COLUMN][MAX_ROW]=

{

{{10,IRQ_EINT0,S3C2410_GPF0,S3C2410_GPE11},/*0行0列*/

{11,IRQ_EINT0,S3C2410_GPF0,S3C2410_GPG6},

{12,IRQ_EINT0,S3C2410_GPF0,S3C2410_GPE13},

{16,IRQ_EINT0,S3C2410_GPF0,S3C2410_GPG2}},

{{7,IRQ_EINT2,S3C2410_GPF2,S3C2410_GPE11},/*1行0列*/

{8,IRQ_EINT2,S3C2410_GPF2,S3C2410_GPG6},

{9,IRQ_EINT2,S3C2410_GPF2,S3C2410_GPE13},

{15,IRQ_EINT2,S3C2410_GPF2,S3C2410_GPG2}},

{{4,IRQ_EINT11,S3C2410_GPG3,S3C2410_GPE11},/*2行0列*/

{5,IRQ_EINT11,S3C2410_GPG3,S3C2410_GPG6},

{6,IRQ_EINT11,S3C2410_GPG3,S3C2410_GPE13},

{14,IRQ_EINT11,S3C2410_GPG3,S3C2410_GPG2}},

{{1,IRQ_EINT19,S3C2410_GPG11,S3C2410_GPE11},/*3行0列*/

{2,IRQ_EINT19,S3C2410_GPG11,S3C2410_GPG6},

{3,IRQ_EINT19,S3C2410_GPG11,S3C2410_GPE13},

{13,IRQ_EINT19,S3C2410_GPG11,S3C2410_GPG2}},

};

下面是與按鍵相關的端口的初始化函數。這些函數已經在簡單的GPIO字符設備驅動程序里被使用過。此外，set_irq_type()函數用于設定中斷線的類型，在本實例中通過該函數將4個中斷線的類型配置為下降沿觸發(fā)式。

staticvoidinit_gpio(void)

{

s3c2410_gpio_cfgpin(S3C2410_GPE11,S3C2410_GPE11_OUTP);/*GPE11*/

s3c2410_gpio_setpin(S3C2410_GPE11,0);

s3c2410_gpio_cfgpin(S3C2410_GPE13,S3C2410_GPE13_OUTP);/*GPE13*/

s3c2410_gpio_setpin(S3C2410_GPE13,0);

s3c2410_gpio_cfgpin(S3C2410_GPG2,S3C2410_GPG2_OUTP);/*GPG2*/

s3c2410_gpio_setpin(S3C2410_GPG2,0);

s3c2410_gpio_cfgpin(S3C2410_GPG6,S3C2410_GPG6_OUTP);/*GPG6*/

s3c2410_gpio_setpin(S3C2410_GPG6,0);

s3c2410_gpio_cfgpin(S3C2410_GPF0,S3C2410_GPF0_EINT0);/*GPF0*/

s3c2410_gpio_cfgpin(S3C2410_GPF2,S3C2410_GPF2_EINT2);/*GPF2*/

s3c2410_gpio_cfgpin(S3C2410_GPG3,S3C2410_GPG3_EINT11);/*GPG3*/

s3c2410_gpio_cfgpin(S3C2410_GPG11,S3C2410_GPG11_EINT19);/*GPG11*/

set_irq_type(IRQ_EINT0,IRQT_FALLING);

set_irq_type(IRQ_EINT2,IRQT_FALLING);

set_irq_type(IRQ_EINT11,IRQT_FALLING);

set_irq_type(IRQ_EINT19,IRQT_FALLING);

}

下面講解按鍵驅動的主要接口，以下為驅動模塊的入口和卸載函數。

/*初始化并添加structcdev結構到系統(tǒng)之中*/

staticvoidbutton_setup_cdev(structcdev*dev,

intminor,structfile_operations*fops)

{

interr;

intdevno=MKDEV(button_major,minor);

cdev_init(dev,fops);/*初始化結構體structcdev*/

dev->owner=THIS_MODULE;

dev->ops=fops;/*關聯(lián)到設備的file_operations結構*/

err=cdev_add(dev,devno,1);/*將structcdev結構添加到系統(tǒng)之中*/

if(err)

{

printk(KERN_INFOError%daddingbutton%dn,err,minor);

}

}

……

/*驅動初始化*/

staticintbutton_init(void)

{

intret;

/*將主設備號和次設備號定義到一個dev_t數據類型的結構體之中*/

dev_tdev=MKDEV(button_major,0);

if(button_major)

{/*靜態(tài)注冊一個設備，設備號先前指定好，并設定設備名，用cat/proc/devices來查看*/

ret=register_chrdev_region(dev,1,BUTTONS_DEVICE_NAME);

}

else

{/*由系統(tǒng)動態(tài)分配主設備號*/

ret=alloc_chrdev_region(dev,0,1,BUTTONS_DEVICE_NAME);

button_major=MAJOR(dev);/*獲得主設備號*/

}

if(ret0)

{

printk(KERN_WARNINGButton:unabletogetmajor%dn,button_major);

returnret;

}

/*初始化和添加結構體structcdev到系統(tǒng)之中*/

button_setup_cdev(button_dev,0,button_fops);

printk(Buttondriverinitialized.n);

return0;

}

/*驅動卸載*/

staticvoid__exitbutton_exit(void)

{

cdev_del(button_dev);/*刪除結構體structcdev*/

/*卸載設備驅動所占有的資源*/

unregister_chrdev_region(MKDEV(button_major,0),1);

printk(Buttondriveruninstalledn);

}

module_init(button_init);/*初始化設備驅動程序的入口*/

module_exit(button_exit);/*卸載設備驅動程序的入口*/

MODULE_AUTHOR(David);

MODULE_LICENSE(DualBSD/GPL);