1. 中断实验

按下key1 led3取反

按下key2 led2取反

按下key3 led1取反

main.c

#include "key.h"
extern void printf(const char *fmt, ...);
void delay_ms(int ms)
{
	int i,j;
	for(i = 0; i < ms;i++)
		for (j = 0; j < 1800; j++);
}

int main()
{
	rcc_init();
	
	led_init(GPIOE,10);
	led_init(GPIOF,10);
	led_init(GPIOE,8);
	
	exti_init(EXTI9,0X05,FALLING);
	exti_init(EXTI8,0X05,FALLING);
	exti_init(EXTI7,0X05,FALLING);

	gic_init(99,0);
	gic_init(98,0);
	gic_init(97,0);

	led_nof(GPIOE,10);
	led_nof(GPIOF,10);
	led_nof(GPIOE,8);
	for(;;);
	return 0;
}

key.h

#ifndef __KEY_H__
#define __KEY_H__
#include "stm32mp1xx_rcc.h"
#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_exti.h"
#include "stm32mp1xx_gic.h"
#define EXTI9 9
#define EXTI8 8
#define EXTI7 7
typedef enum{
 	RISING,
	FALLING
}trigger;

//初始化gcc gicdctlr giccctlr
void rcc_init();
//初始化exti 编号 gpio组号 触发方式
void exti_init(int num,unsigned int gid,trigger t);
//初始化 gic 中断号 优先级
void gic_init(int num,unsigned int priority);
//初始化led
void led_init(gpio_t* gpio,int pin);
//开关led
void led_nof(gpio_t* gpio,int pin);
#endif

key.c

#include "key.h"

void rcc_init()
{
	//rcc
	RCC->MP_AHB4ENSETR |= (3<<4);	
	//gicd_ctrl
	GICD->CTRL |= 1;
	//gicc_ctrl
	GICC->CTRL |= 1;
    //gicc_pmr
    GICC->PMR |= (0X1F << 3);	
}

void exti_init(int num,unsigned int gid,trigger t)
{
	GPIOF->MODER &= ~(3 << (num*2));
	if((num/4) == 2)
	{
		EXTI->EXTICR3 &= ~(0XFF << (num%4*8));
		EXTI->EXTICR3 |= (gid << (num%4*8));
	}
	else
	{	
		EXTI->EXTICR2 &= ~(0XFF << (num%4*8));
		EXTI->EXTICR2 |= (gid << (num%4*8));
	}
	//extiftsr1
	if(t == FALLING) 
		EXTI->FTSR1 |= (1 << num);
	//extiimr1
	EXTI->C1IMR1 |= (1 << num);
}

void gic_init(int num,unsigned int priority)
{
	//gicd_isenabler
	GICD->ISENABLER[num/32] |= (1 << (num%32));
	//gicd_ipriorityr
	GICD->IPRIORITYR[num/4] &= ~(0X1F << (num%4*8+3));
	GICD->IPRIORITYR[num/4] |= (priority << (num%4*8+3));
	//GICD_ITARGETSR
	GICD->ITARGETSR[num/4] |= (1 << (num%4*8));	
}

void led_init(gpio_t* gpio,int pin)
{
	//模式设置为输出
	gpio->MODER &= ~(3 << (pin*2));
	gpio->MODER |= (1 << (pin*2));
	
	gpio->OTYPER &= ~(1 << pin);

	gpio->OSPEEDR &= ~(3 << (pin*2));

	gpio->PUPDR &= ~(3 << (pin*2));
}

void led_nof(gpio_t* gpio,int pin)
{
	gpio->ODR ^= (1 << pin);
}

do_irq.c

extern void printf(const char *fmt, ...);
#include "key.h"
void do_irq(void) 
{
	//判断中断号
	unsigned int iar = GICC->IAR;
	unsigned int num = iar & 0x3ff;
	printf("key\n");
	switch(num)
	{
		case 97:
		{
			led_nof(GPIOF,10);
			//清除exti
			EXTI->FPR1 |= (1 << (num-90));
			//gicd_icpendr 清除gicd
			GICD->ICPENDR[num/32] |= (1 << (num%32));
			break;
		}
		case 98:
		{
			led_nof(GPIOE,10);
			//清除exti
			EXTI->FPR1 |= (1 << (num-90));
			//gicd_icpendr 清除gicd
			GICD->ICPENDR[num/32] |= (1 << (num%32));
			break;
		}
		case 99:
		{
			led_nof(GPIOE,8);
			//清除exti
			EXTI->FPR1 |= (1 << (num-90));
			//gicd_icpendr 清除gicd
			GICD->ICPENDR[num/32] |= (1 << (num%32));
			break;
		}
	}
	//清除 GICC
	GICC->EOIR = iar;
}