问题：有关申请irq问题

编译驱动遇到的问题
在代码中有包含以下头文件：
#include <asm/irq.h>
#include <linux/interrupt.h>
#include <asm-arm/arch-s3c2410/irqs.h>
#include <linux/irq.h>


相关代码：  
set_external_irq(HPI_INT,EXT_LOWLEVEL,GPIO_PULLUP_DIS);
if(0!=request_irq(HPI_INT,&hpi_interrupt,SA_SHIRQ,"hpi",hpi_dev)){
        printk("hpi request_irq failed...");
        goto fail_request_irq;

为什么编译的时候还会出现如下问题：
337: error: implicit declaration of function ‘set_external_irq’
337: error: ‘EXT_LOWLEVEL’ undeclared (first use in this function)
337: error: (Each undeclared identifier is reported only once
337: error: for each function it appears in.)
337: error: ‘GPIO_PULLUP_DIS’ undeclared (first use in this function)
338: error: ‘SA_SHIRQ’ undeclared (first use in this function)
338: warning: passing argument 2 of ‘request_irq’ from incompatible pointer type


还有
unsigned char a1,a2;
outb(a1,hpi_dev->hpi_vbase+0x1c);
outb(a2,hpi_dev->hpi_vbase+0x1e);

会出现如下警告：
warning: passing argument 2 of ‘outb’ makes integer from pointer without a cast

希望各位大牛能帮帮忙哈，感激不尽