嵌入式学习——硬件（Linux内核驱动编程LED、蜂鸣器、按键）——day59

时间：2024-07-05 22:30:07

1. 编写LED驱动（初始化所有子设备号）

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#define GPBCON  (0x56000010)
#define GPBDAT  (0x56000014)
static unsigned int *regGPBCON;
static unsigned int *regGPBDAT;

int led_driver_open(struct inode *p_node, struct file *fp)
{
	printk("open\n");
	return 0;
}

ssize_t led_driver_read(struct file *fp, char __user *user_buffer, size_t n, loff_t * offset)
{
	printk("read\n");
	return 0;
}

void ledOn(unsigned int n)
{
	*regGPBDAT |= (0x0F << 5);
	if(n < 1 || n > 4)
	{
		return;
	}
	*regGPBDAT &= ~(1 << (n + 4));
}

ssize_t led_driver_write(struct file *fp, const char __user *user_buffer, size_t n, loff_t *offset)
{
	char s[10];
	
	copy_from_user(s, user_buffer, n);
	ledOn(s[0]);

	printk("write\n");
	return n;
}

int led_driver_close(struct inode *p_node, struct file *fp)
{
	printk("close\n");
	return 0;
}

struct file_operations fops =
{	
	.owner = THIS_MODULE,
	.release = led_driver_close,
	.open = led_driver_open,
	.read = led_driver_read,
	.write = led_driver_write,
};

static int __init led_driver_init(void)
{	
	int ret;
	printk("init\n");
	ret = register_chrdev(200, "first driver", &fops);
	if(ret != 0)
	{
		return ret;
	}

	regGPBCON = ioremap(GPBCON, 4);
	regGPBDAT = ioremap(GPBDAT, 4);

	*regGPBCON &= ~((3 << 10) | (3 << 12) | (3 << 14) | (3 << 16));
	*regGPBCON |= (1 << 10) | (1 << 12) | (1 << 14) | (1 << 16);

	*regGPBDAT |= (0x0F << 5);
	return 0;
}

static void __exit led_driver_exit(void)
{
	iounmap(regGPBDAT);
	iounmap(regGPBCON);

	unregister_chrdev(200, "first driver");
	printk("exit\n");
}

module_init(led_driver_init);
module_exit(led_driver_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("PuTe");

2. 编写LED驱动（初始化一个子设备号）

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#define GPBCON  (0x56000010)
#define GPBDAT  (0x56000014)
static unsigned int *regGPBCON;
static unsigned int *regGPBDAT;
static dev_t dev_num;
struct cdev led_dev;

int led_driver_open(struct inode *p_node, struct file *fp)
{
	printk("open\n");
	return 0;
}

ssize_t led_driver_read(struct file *fp, char __user *user_buffer, size_t n, loff_t * offset)
{
	printk("read\n");
	return 0;
}

void ledOn(unsigned int n)
{
	*regGPBDAT |= (0x0F << 5);

	if(n < 1 || n > 4)
	{
		return;
	}

	*regGPBDAT &= ~(1 << (n + 4));
}

ssize_t led_driver_write(struct file *fp, const char __user *user_buffer, size_t n, loff_t *offset)
{
	char s[10];
	
	copy_from_user(s, user_buffer, n);
	ledOn(s[0]);
	printk("write\n");

	return n;
}

int led_driver_close(struct inode *p_node, struct file *fp)
{
	printk("close\n");
	return 0;
}

struct file_operations fops =
{	
	.owner = THIS_MODULE,
	.release = led_driver_close,
	.open = led_driver_open,
	.read = led_driver_read,
	.write = led_driver_write,
};

static int __init led_driver_init(void)
{	
	int ret;

	ret = alloc_chrdev_region(&dev_num, 0, 1, "first device");
	if(ret)
	{
		printk("alloc_chrdev_region is error\n");
		return ret;
	}
	
	printk("major = %u, minior = %u\n", MAJOR(dev_num), MINOR(dev_num));

	cdev_init(&led_dev, &fops);
	ret = cdev_add(&led_dev, dev_num, 1);
	if(ret)
	{
		unregister_chrdev_region(dev_num, 1);
		printk("cdev_add is error\n");
		return ret;
	}

	regGPBCON = ioremap(GPBCON, 4);
	regGPBDAT = ioremap(GPBDAT, 4);

	*regGPBCON &= ~((3 << 10) | (3 << 12) | (3 << 14) | (3 << 16));
	*regGPBCON |= (1 << 10) | (1 << 12) | (1 << 14) | (1 << 16);
	*regGPBDAT |= (0x0F << 5);

	return 0;
}

static void __exit led_driver_exit(void)
{
	iounmap(regGPBDAT);
	iounmap(regGPBCON);

	cdev_del(&led_dev);
	unregister_chrdev_region(dev_num, 1);
	printk("exot\n");
}

module_init(led_driver_init);
module_exit(led_driver_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("PuTe");

3. LED标准字符设备驱动（省去在linux终端mknod的过程，直接insmod的即可运行程序）

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#define GPBCON  (0x56000010)
#define GPBDAT  (0x56000014)
static unsigned int *regGPBCON;
static unsigned int *regGPBDAT;
static dev_t dev_num;
struct cdev led_dev;
static struct class *p_class;
static struct device *p_device;

int led_driver_open(struct inode *p_node, struct file *fp)
{
	printk("open\n");
	return 0;
}

ssize_t led_driver_read(struct file *fp, char __user *user_buffer, size_t n, loff_t * offset)
{
	printk("read\n");
	return 0;
}

void ledOn(unsigned int n)
{
	*regGPBDAT |= (0x0F << 5);

	if(n < 1 || n > 4)
	{
		return;
	}

	*regGPBDAT &= ~(1 << (n + 4));
}

ssize_t led_driver_write(struct file *fp, const char __user *user_buffer, size_t n, loff_t *offset)
{
	char s[10];
	
	copy_from_user(s, user_buffer, n);
	ledOn(s[0]);
	printk("write\n");

	return n;
}

int led_driver_close(struct inode *p_node, struct file *fp)
{
	printk("close\n");
	return 0;
}

struct file_operations fops =
{	
	.owner = THIS_MODULE,
	.release = led_driver_close,
	.open = led_driver_open,
	.read = led_driver_read,
	.write = led_driver_write,
};

static int __init led_driver_init(void)
{	
	int ret;

	ret = alloc_chrdev_region(&dev_num, 0, 1, "first device");
	if(ret)
	{
		printk("alloc_chrdev_region is error\n");
		goto alloc_chrdev_region_err;
	}
	
	printk("major = %u, minior = %u\n", MAJOR(dev_num), MINOR(dev_num));

	cdev_init(&led_dev, &fops);
	ret = cdev_add(&led_dev, dev_num, 1);
	if(ret)
	{
		printk("cdev_add is error\n");
		goto cdev_add_err;
	}

	p_class = class_create(THIS_MODULE, "Led class");
	if(IS_ERR(p_class))
	{
		printk("class_create is error!");
		goto class_create_err;
	}

	p_device = device_create(p_class, NULL, dev_num, NULL, "led");
	if(p_device == NULL)
	{
		printk("device_create is error\n");
		goto device_create_err;
	}

	regGPBCON = ioremap(GPBCON, 4);
	regGPBDAT = ioremap(GPBDAT, 4);

	*regGPBCON &= ~((3 << 10) | (3 << 12) | (3 << 14) | (3 << 16));
	*regGPBCON |= (1 << 10) | (1 << 12) | (1 << 14) | (1 << 16);
	*regGPBDAT |= (0x0F << 5);

	return 0;

device_create_err:
	class_destroy(p_class);
class_create_err:
	cdev_del(&led_dev);
cdev_add_err:
	unregister_chrdev_region(dev_num, 1);
alloc_chrdev_region_err:
	return ret;
}

static void __exit led_driver_exit(void)
{
	iounmap(regGPBDAT);
	iounmap(regGPBCON);

	device_destroy(p_class, dev_num);
	class_destroy(p_class);
	cdev_del(&led_dev);
	unregister_chrdev_region(dev_num, 1);
	printk("exit\n");
}

module_init(led_driver_init);
module_exit(led_driver_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("PuTe");

4. 蜂鸣器——混杂设备驱动

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#define GPBCON (0x56000010)
#define GPBDAT (0x56000014)
static unsigned int *regGPBCON;
static unsigned int *regGPBDAT;

int beep_open(struct inode *p_node, struct file *fp)
{
	return 0;
}

int beep_release(struct inode *p_node, struct file *fp)
{
	return 0;
}

ssize_t beep_write(struct file *fp, const char __user *user_buffer, size_t n, loff_t * offset)
{
	int ret;

	copy_from_user(&ret, user_buffer, 4);
	printk("kernel : %d",ret);
	if(ret)
	{
		*regGPBDAT |= (1 << 0);
	}
	else
	{
		*regGPBDAT &= ~(1 << 0);
	}

	return 4;
}

static struct file_operations fops =
{
	.owner = THIS_MODULE,
	.open = beep_open,
	.release = beep_release,
	.write = beep_write
};

static struct miscdevice beep_device =
{
	.minor = MISC_DYNAMIC_MINOR,
	.name = "beep",
	.fops = &fops,
};

static int __init beep_init(void)
{
	int ret;

	ret = misc_register(&beep_device);
	if(ret)
	{
		printk("misc_register is error");
		return ret;
	}
	
	regGPBCON = ioremap(GPBCON, 4);
	regGPBDAT = ioremap(GPBDAT, 4);

	*regGPBCON &= ~(3 << 0);
	*regGPBCON |= (1 << 0);

	return 0;
}

static void __exit beep_exit(void)
{
	iounmap(regGPBCON);
	iounmap(regGPBDAT);
	misc_deregister(&beep_device);
}

module_init(beep_init);
module_exit(beep_exit);

MODULE_LICENSE("GPL");

5. 按键（轮询查看按键）——混杂设备驱动

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#define GPGCON (0x56000060)
#define GPGDAT (0x56000064)
#define GPGUP (0x56000068)

static unsigned int *regGPGCON;
static unsigned int *regGPGDAT;
static unsigned int *regGPGUP;

int key_open(struct inode *p_node, struct file *fp)
{
	return 0;
}

int key_release(struct inode *p_node, struct file *fp)
{
	return 0;
}

ssize_t key_write(struct file *fp, const char __user *user_buffer, size_t n, loff_t * offset)
{
	return 0;
}

ssize_t key_read(struct file *fp, char __user *user_buffer, size_t n, loff_t *offset)
{
	int ret = -1;

	if (0 == (*regGPGDAT & (1 << 0)))
	{
		ret = 1;
	}
	else if (0 == (*regGPGDAT & (1 << 3)))
	{
		ret = 2;
	}
	else if (0 == (*regGPGDAT & (1 << 5)))
	{
		ret = 3;
	}
	else if (0 == (*regGPGDAT & (1 << 6)))
	{
		ret = 4;
	}
	else if (0 == (*regGPGDAT & (1 << 7)))
	{
		ret = 5;
	}
	else if (0 == (*regGPGDAT & (1 << 11)))
	{
		ret = 6;
	}
	
	if (ret != (-1))
	{
		copy_to_user(user_buffer, &ret, 4);
	}

	return 0;
}

static struct file_operations fops =
{
	.owner = THIS_MODULE,
	.open = key_open,
	.release = key_release,
	.write = key_write,
	.read = key_read,
};

static struct miscdevice key_device =
{
	.minor = MISC_DYNAMIC_MINOR,
	.name = "key",
	.fops = &fops,
};

static int __init key_init(void)
{
	int ret;
	ret = misc_register(&key_device);
	if(ret)
	{
		printk("misc_register is error");
		return ret;
	}
	
	regGPGCON = ioremap(GPGCON, 4);
	regGPGDAT = ioremap(GPGDAT, 4);
	regGPGUP = ioremap(GPGUP, 4);

	*regGPGCON &= ~((3 << 0) | (3 << 6) | (3 << 10) | (3 << 12) | (3 << 14) | (3 << 22));	
	*regGPGDAT |= ((1 << 0) | (1 << 3) | (1 << 5) | (1 << 6) | (1 << 7) | (1 << 11));
	*regGPGUP |= ((1 << 0) | (1 << 11));
	*regGPGUP &= ~((1 << 3) | (1 << 5) | (1 << 6) | (1 << 7));

	return 0;
}

static void __exit key_exit(void)
{
	iounmap(regGPGCON);
	iounmap(regGPGDAT);
	iounmap(regGPGUP);
	misc_deregister(&key_device);
}


module_init(key_init);
module_exit(key_exit);

MODULE_LICENSE("GPL");

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