作业1
myled_time.c
#include <linux/init.h>
#include <linux/module.h>
#include<linux/of.h>
#include<linux/gpio.h>
#include<linux/of_gpio.h>
#include<linux/timer.h>
struct device_node *dnode;
unsigned int gpiono;
struct timer_list mytimer; //定义定时器对象
//定义定时器处理函数
void mytimer_func(struct timer_list *timer)
{
if(gpio_get_value(gpiono) == 1)
{
//灯灭
gpio_set_value(gpiono,0);
}
else if(gpio_get_value(gpiono) == 0)
{
//灯亮
gpio_set_value(gpiono,1);
}
mod_timer(timer,jiffies+HZ);
}
static int __init mycdev_init(void)
{
int ret;
//解析led灯的设备树节点
dnode=of_find_node_by_path("/myleds");
if(dnode==NULL)
{
printk("解析设备树节点失败\n");
return -ENXIO;
}
printk("解析设备树节点成功\n");
//根据设备树节点解析led1gpio编号
gpiono=of_get_named_gpio(dnode,"led1",0);
if(gpiono<0)
{
printk("gpio编号解析失败\n");
}
printk("解析gpio编号成功gpiono=%d\n",gpiono);
//申请gpio编号
ret=gpio_request(gpiono,NULL);
if(ret<0)
{
printk("申请gpio编号失败\n");
return ret;
}
//led1对应的gpio的管脚为输出
gpio_direction_output(gpiono,0);
//设置管脚输出高电平，亮灯
gpio_set_value(gpiono,1);
//初始化定时器对象
mytimer.expires=jiffies+HZ;
timer_setup(&mytimer,mytimer_func,0);
//将定时器对象注册进内核
add_timer(&mytimer);
return 0;
}
static void __exit mycdev_exit(void)
{
//灭灯
gpio_set_value(gpiono,0);
//释放gpio编号
gpio_free(gpiono);
//注销定时器
del_timer(&mytimer);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");
作业2
mychrdev.c
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/slab.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/of.h>
#define LED_ON _IO('l',1)
#define LED_OFF _IO('l',0)
struct class *cls;
struct device *dev;
struct cdev *cdev;
unsigned int major = 0;
unsigned int minor = 0;
dev_t devnob;
struct device_node *dnode;
struct gpio_desc *gpiono1;
struct gpio_desc *gpiono2;
struct gpio_desc *gpiono3;
int mycdev_open(struct inode *inode, struct file *file)
{
unsigned int aaa = MINOR(inode->i_rdev);
file->private_data = (void *)aaa;
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
return 0;
}
long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
unsigned int aaa = (int)file->private_data;
switch (cmd)
{
case LED_ON: // 开灯
switch (aaa)
{
case 0: // LED1
gpiod_set_value(gpiono1, 1);
break;
case 1: // LED2
gpiod_set_value(gpiono2, 1);
break;
case 2: // LED3
gpiod_set_value(gpiono3, 1);
break;
}
break;
case LED_OFF: // 关灯
switch (aaa)
{
case 0:
gpiod_set_value(gpiono1, 0);
break;
case 1:
gpiod_set_value(gpiono2, 0);
break;
case 2:
gpiod_set_value(gpiono3, 0);
break;
}
break;
}
return 0;
}
int mycdev_close(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
return 0;
}
struct file_operations fops =
{
.open = mycdev_open,
.unlocked_ioctl = mycdev_ioctl,
.release = mycdev_close,
};
static int __init mycdev_init(void)
{
int ret, i;
// 1.分配字符设备驱动对象空间 cdev_alloc
cdev = cdev_alloc();
if (cdev == NULL)
{
printk("申请字符设备驱动对象空间失败\n");
ret = -EFAULT;
goto out1;
}
printk("字符设备驱动对象申请成功\n");
// 2.字符设备驱动对象部分初始化 cdev_init
cdev_init(cdev, &fops);
// 3.申请设备号 register_chrdev_region/alloc_chrdev_region
if (major > 0)
{
ret = register_chrdev_region(MKDEV(major, minor), 3, "myled");
if (ret)
{
printk("静态指定设备号失败\n");
goto out2;
}
}
else
{
ret = alloc_chrdev_region(&devnob, minor, 3, "myled");
if (ret)
{
printk("静态指定设备号失败\n");
goto out2;
}
major = MAJOR(devnob); // 根据设备号得到主设备号
minor = MINOR(devnob); // 根据设备号得到次设备号
}
printk("申请设备号成功\n");
// 4.注册字符设备驱动对象 cdev_add()
ret = cdev_add(cdev, MKDEV(major, minor), 3);
if (ret)
{
printk("注册字符设备驱动对象失败\n");
goto out3;
}
printk("注册字符设备驱动对象成功\n");
// 5.向上提交目录
cls = class_create(THIS_MODULE, "myled");
if (IS_ERR(cls))
{
printk("向上提交目录失败\n");
ret = -PTR_ERR(cls);
goto out4;
}
printk("向上提交目录成功\n");
// 6.向上提交设备节点
for (i = 0; i < 3; i++)
{
dev = device_create(cls, NULL, MKDEV(major, i), NULL, "myled%d", i);
if (IS_ERR(dev))
{
printk("向上提交节点信息失败\n");
ret = -PTR_ERR(dev);
goto out5;
}
}
printk("向上提交设备节点信息成功\n");
// 解析led灯的设备树节点
dnode = of_find_node_by_path("/myleds");
if (dnode == NULL)
{
printk("解析设备树节点失败\n");
return -ENXIO;
}
printk("解析设备树节点成功\n");
// 根据设备树节点解析led1gpio结构体并向内核注册
gpiono1 = gpiod_get_from_of_node(dnode, "led1", 0, GPIOD_OUT_LOW, NULL);
if (IS_ERR(gpiono1))
{
printk("申请gpiono1失败\n");
return -PTR_ERR(gpiono1);
}
// 根据设备树节点解析led2gpio结构体并向内核注册
gpiono2 = gpiod_get_from_of_node(dnode, "led2", 0, GPIOD_OUT_LOW, NULL);
if (IS_ERR(gpiono2))
{
printk("申请gpiono2失败\n");
return -PTR_ERR(gpiono2);
}
// 根据设备树节点解析led3gpio结构体并向内核注册
gpiono3 = gpiod_get_from_of_node(dnode, "led3", 0, GPIOD_OUT_LOW, NULL);
if (IS_ERR(gpiono3))
{
printk("申请gpiono3失败\n");
return -PTR_ERR(gpiono3);
}
printk("申请gpio编号成功\n");
return 0;
out5:
for (--i; i >= 0; i--)
{
// 销毁上面提交的设备信息
device_destroy(cls, MKDEV(major, i));
}
class_destroy(cls);
out4:
cdev_del(cdev);
out3:
unregister_chrdev_region(MKDEV(major, minor), 3);
out2:
kfree(cdev);
out1:
return ret;
}
static void __exit mycdev_exit(void)
{
int i;
// 灭灯
gpiod_set_value(gpiono1, 0);
gpiod_set_value(gpiono2, 0);
gpiod_set_value(gpiono3, 0);
// 释放gpio编号
gpiod_put(gpiono1);
gpiod_put(gpiono2);
gpiod_put(gpiono3);
// 1.销毁设备信息 device_destroy
for (i = 0; i < 3; i++)
{
device_destroy(cls, MKDEV(major, i));
}
// 2.销毁目录 class_destroy
class_destroy(cls);
// 3.注销对象 cdev_del()
cdev_del(cdev);
// 4.释放设备号 unregister_chrdev_region()
unregister_chrdev_region(MKDEV(major, minor), 3);
// 5.释放对象空间 kfree()
kfree(cdev);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");
test.c
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>
#define LED_ON _IO('l',1)
#define LED_OFF _IO('l',0)
// LED1->PE10
// LED2->PF10
// LED3->PE8
int main(int argc, char const *argv[])
{
int a, b;
int fd;
while (1)
{
// 从终端读取
printf("请选择要实现的功能\n");
printf("0(关灯) 1(开灯)>");
scanf("%d", &a);
printf("请输入要控制的灯\n");
printf("1(LED1) 2(LED2) 3(LED3)>");
scanf("%d", &b);
if (a == 1) // 开灯
{
switch (b)
{
case 1:
fd = open("/dev/myled0", O_RDWR);
if (fd < 0)
{
printf("打开设备文件失败\n");
exit(-1);
}
ioctl(fd, LED_ON);
break;
case 2:
fd = open("/dev/myled1", O_RDWR);
if (fd < 0)
{
printf("打开设备文件失败\n");
exit(-1);
}
ioctl(fd,LED_ON);
break;
case 3:
fd = open("/dev/myled2", O_RDWR);
if (fd < 0)
{
printf("打开设备文件失败\n");
exit(-1);
}
ioctl(fd, LED_ON);
break;
}
}
else if (a == 0) // 关灯
{
switch (b)
{
case 1:
fd = open("/dev/myled0", O_RDWR);
if (fd < 0)
{
printf("打开设备文件失败\n");
exit(-1);
}
ioctl(fd,LED_OFF);
break;
case 2:
fd = open("/dev/myled1", O_RDWR);
if (fd < 0)
{
printf("打开设备文件失败\n");
exit(-1);
}
ioctl(fd, LED_OFF);
break;
case 3:
fd = open("/dev/myled2", O_RDWR);
if (fd < 0)
{
printf("打开设备文件失败\n");
exit(-1);
}
ioctl(fd, LED_OFF);
break;
}
}
}
close(fd);
return 0;
}
