驱动开发 作业1

1. 下面代码中的 gpio.h 和 rcc.h 是 led 项目中的 common/include 目录下的 stm32mp1xx_gpio.h 和 stm32mp1xx_rcc.h 所以不贴代码了，完整的目录查看这个仓库
2. 这里直接把 GPIOE/GPIOF，RCC 结构体的地址映射到虚拟地址中
3. 用户空间应用程序的代码没有修改，也不贴上来了，输入 1，2，3 分别对应开关 LED1，2，3

#include 
#include 
#include 
#include 
#include 
#include "gpio.h"
#include "rcc.h"

int major; // 用于保存主设备号
char kbuf[128] = { 0 };
unsigned int *vir_gpioe;
unsigned int *vir_gpiof;
unsigned int *vir_rcc;

// 封装操作方法
int mycdev_open(struct inode *inode, struct file *file)
{
	printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
	return 0;
}

ssize_t mycdev_read(struct file *file, char *ubuf, size_t size, loff_t *lof)
{
	int ret;
	if (sizeof(kbuf) < size)
		size = sizeof(kbuf);
	ret = copy_to_user(ubuf, kbuf, size);
	if (ret) {
		printk("copy_tO_user filed\n");
		return -EIO;
	}
	printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
	return 0;
}

ssize_t mycdev_write(struct file *file, const char *ubuf, size_t size,
		     loff_t *lof)
{
	int ret;
	//判断用户空间的需求是否能被驱动满足，满足不了就给能给的最好的
	if (sizeof(kbuf) < size)
		size = sizeof(kbuf);
	ret = copy_from_user(kbuf, ubuf, size);
	if (ret) {
		printk("copy_from_user filed\n");
		return -EIO;
	}
	if (kbuf[0] == '1') { // 开关 LED1 PE10
		((gpio_t *)vir_gpioe)->ODR ^= (0x1 << 10);
	} else if (kbuf[0] == '2') { // 开关 LED2 PF10
		((gpio_t *)vir_gpiof)->ODR ^= (0x1 << 10);
	} else if (kbuf[0] == '3') { // 开关 LED3 PE8
		((gpio_t *)vir_gpioe)->ODR ^= (0x1 << 8);
	}
	printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
	return 0;
}

int mycdev_close(struct inode *inode, struct file *file)
{
	printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
	return 0;
}

// 定义操作方法结构体变量并完成初始化
struct file_operations fops = {
	.open = mycdev_open,
	.read = mycdev_read,
	.write = mycdev_write,
	.release = mycdev_close,
};

static int __init mycdev_init(void)
{
	//字符设备驱动注册
	major = register_chrdev(0, "mychrdev", &fops);
	if (major < 0) {
		printk("字符设备驱动注册失败\n");
		return major;
	}
	printk("字符设备驱动注册成功major=%d\n", major);
	//映射物理寄存器
	vir_gpioe = ioremap((volatile unsigned int)GPIOE, sizeof(gpio_t));
	if (vir_gpioe == NULL) {
		printk("GPIOE结构体映射表失败\n");
		return -EFAULT;
	}
	vir_gpiof = ioremap((volatile unsigned int)GPIOF, sizeof(gpio_t));
	if (vir_gpioe == NULL) {
		printk("GPIOF结构体映射表失败\n");
		return -EFAULT;
	}
	vir_rcc = ioremap((volatile unsigned int)RCC, sizeof(rcc_t));
	if (vir_rcc == NULL) {
		printk("RCC结构体映射表失败\n");
		return -EFAULT;
	}
	printk("寄存器地址映射成功\n");
	//寄存器初始化
	((rcc_t *)vir_rcc)->MP_AHB4ENSETR |= (1 << 4) | (1 << 5);
	// LED1 初始化
	((gpio_t *)vir_gpioe)->MODER &= (~(0x3 << 20));
	((gpio_t *)vir_gpioe)->MODER |= (0x1 << 20);
	((gpio_t *)vir_gpioe)->ODR &= (~(0x1 << 10));
	// LED2 初始化
	((gpio_t *)vir_gpiof)->MODER &= (~(0x3 << 20));
	((gpio_t *)vir_gpiof)->MODER |= (0x1 << 20);
	((gpio_t *)vir_gpiof)->ODR &= (~(0x1 << 10));
	// LED3 初始化
	((gpio_t *)vir_gpioe)->MODER &= (~(0x3 << 16));
	((gpio_t *)vir_gpioe)->MODER |= (0x1 << 16);
	((gpio_t *)vir_gpioe)->ODR &= (~(0x1 << 8));

	printk("硬件寄存器初始化成功\n");
	return 0;
}

static void __exit mycdev_exit(void)
{
	//取消寄存器地址映射
	iounmap(vir_gpioe);
	iounmap(vir_gpiof);
	iounmap(vir_rcc);
	//字符设备驱动的注销
	unregister_chrdev(major, "mychrdev");
}

module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");