在编写Linux驱动程序时。我想用某一个引脚做外部中断。可是在调用

int request_irq(unsigned int irq, 

void (*handler)(int irq, void *dev_id, struct pt_regs *regs 

),

unsigned long irqflags, 

const char * devname, 

void *dev_id); 

这个函数的时候遇到了一个问题，irq是个硬件终端号，可是究竟这个引脚相应的终端号是多少呢？

我在网上找资料说的都稀里糊涂的，不是我想要的答案。

于是我便在内核代码里找，以下贴出Linux内核代码的一段archarmmach-s3c64xxincludemachIrqs.h，能够解释这个问题：

/* Since the IRQ_EINT(x) are a linear mapping on current s3c64xx series

 * we just defined them as an IRQ_EINT(x) macro from S3C_IRQ_EINT_BASE

 * which we place after the pair of VICs. */

#define S3C_IRQ_EINT_BASE S3C_IRQ(64+5)

#define S3C_EINT(x) ((x) + S3C_IRQ_EINT_BASE)

#define IRQ_EINT(x) S3C_EINT(x)

#define IRQ_EINT_BIT(x) ((x) - S3C_EINT(0))

/* Next the external interrupt groups. These are similar to the IRQ_EINT(x)

 * that they are sourced from the GPIO pins but with a different scheme for

 * priority and source indication.

 *

 * The IRQ_EINT(x) can be thought of as 'group 0' of the available GPIO

 * interrupts, but for historical reasons they are kept apart from these

 * next interrupts.

 *

 * Use IRQ_EINT_GROUP(group, offset) to get the number for use in the

 * machine specific support files.

 */

#define IRQ_EINT_GROUP1_NR (15)

#define IRQ_EINT_GROUP2_NR (8)

#define IRQ_EINT_GROUP3_NR (5)

#define IRQ_EINT_GROUP4_NR (14)

#define IRQ_EINT_GROUP5_NR (7)

#define IRQ_EINT_GROUP6_NR (10)

#define IRQ_EINT_GROUP7_NR (16)

#define IRQ_EINT_GROUP8_NR (15)

#define IRQ_EINT_GROUP9_NR (9)

#define IRQ_EINT_GROUP_BASE S3C_EINT(28)

#define IRQ_EINT_GROUP1_BASE (IRQ_EINT_GROUP_BASE + 0x00)

#define IRQ_EINT_GROUP2_BASE (IRQ_EINT_GROUP1_BASE + IRQ_EINT_GROUP1_NR)

#define IRQ_EINT_GROUP3_BASE (IRQ_EINT_GROUP2_BASE + IRQ_EINT_GROUP2_NR)

#define IRQ_EINT_GROUP4_BASE (IRQ_EINT_GROUP3_BASE + IRQ_EINT_GROUP3_NR)

#define IRQ_EINT_GROUP5_BASE (IRQ_EINT_GROUP4_BASE + IRQ_EINT_GROUP4_NR)

#define IRQ_EINT_GROUP6_BASE (IRQ_EINT_GROUP5_BASE + IRQ_EINT_GROUP5_NR)

#define IRQ_EINT_GROUP7_BASE (IRQ_EINT_GROUP6_BASE + IRQ_EINT_GROUP6_NR)

#define IRQ_EINT_GROUP8_BASE (IRQ_EINT_GROUP7_BASE + IRQ_EINT_GROUP7_NR)

#define IRQ_EINT_GROUP9_BASE (IRQ_EINT_GROUP8_BASE + IRQ_EINT_GROUP8_NR)

#define IRQ_EINT_GROUP(group, no) (IRQ_EINT_GROUP##group##_BASE + (no))

从以上凝视以及代码能够看到。有两个宏来获得终端号，

IRQ_EINT(x)                                                第0组

IRQ_EINT_GROUP（group,no）          第1-9组