书写hall驱动代码
时间: 2024-02-05 09:13:52 浏览: 26
以下是一个简单的Hall传感器驱动程序,用于在Linux系统上读取Hall传感器的值:
```c
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("Hall Sensor Driver");
#define DEVICE_NAME "hall_sensor"
#define CLASS_NAME "hall"
//GPIO pin for Hall sensor
static unsigned int hall_gpio_pin = 17;
static unsigned int irq_num;
static int major_number;
static struct class* hall_class = NULL;
static struct device* hall_device = NULL;
static irq_handler_t hall_irq_handler(unsigned int irq, void *dev_id, struct pt_regs *regs)
{
printk(KERN_INFO "Hall Sensor: Interrupt occurred.\n");
return (irq_handler_t) IRQ_HANDLED;
}
static int hall_open(struct inode *inodep, struct file *filep)
{
printk(KERN_INFO "Hall Sensor: Device opened.\n");
return 0;
}
static ssize_t hall_read(struct file *filep, char *buffer, size_t len, loff_t *offset)
{
printk(KERN_INFO "Hall Sensor: Reading sensor value.\n");
//Read the value of the Hall sensor from GPIO pin
int sensor_value = gpio_get_value(hall_gpio_pin);
if (sensor_value == 0) {
strcpy(buffer, "Magnetic field detected.");
} else {
strcpy(buffer, "No magnetic field detected.");
}
return strlen(buffer);
}
static int hall_release(struct inode *inodep, struct file *filep)
{
printk(KERN_INFO "Hall Sensor: Device closed.\n");
return 0;
}
static struct file_operations fops =
{
.open = hall_open,
.read = hall_read,
.release = hall_release,
};
static int __init hall_init(void)
{
printk(KERN_INFO "Hall Sensor: Initializing driver.\n");
//Request GPIO pin for Hall sensor
if (!gpio_is_valid(hall_gpio_pin)) {
printk(KERN_ALERT "Hall Sensor: Invalid GPIO pin.\n");
return -ENODEV;
}
if (gpio_request(hall_gpio_pin, "hall_sensor")) {
printk(KERN_ALERT "Hall Sensor: Failed to request GPIO pin.\n");
return -EINVAL;
}
gpio_direction_input(hall_gpio_pin);
//Request IRQ for Hall sensor
irq_num = gpio_to_irq(hall_gpio_pin);
if (request_irq(irq_num, (irq_handler_t) hall_irq_handler, IRQF_TRIGGER_RISING, "hall_sensor", NULL)) {
printk(KERN_ALERT "Hall Sensor: Failed to request IRQ.\n");
return -EINVAL;
}
//Register device
major_number = register_chrdev(0, DEVICE_NAME, &fops);
if (major_number < 0) {
printk(KERN_ALERT "Hall Sensor: Failed to register device.\n");
return major_number;
}
hall_class = class_create(THIS_MODULE, CLASS_NAME);
if (IS_ERR(hall_class)) {
unregister_chrdev(major_number, DEVICE_NAME);
printk(KERN_ALERT "Hall Sensor: Failed to create device class.\n");
return PTR_ERR(hall_class);
}
hall_device = device_create(hall_class, NULL, MKDEV(major_number, 0), NULL, DEVICE_NAME);
if (IS_ERR(hall_device)) {
class_destroy(hall_class);
unregister_chrdev(major_number, DEVICE_NAME);
printk(KERN_ALERT "Hall Sensor: Failed to create device.\n");
return PTR_ERR(hall_device);
}
printk(KERN_INFO "Hall Sensor: Driver initialized.\n");
return 0;
}
static void __exit hall_exit(void)
{
printk(KERN_INFO "Hall Sensor: Exiting driver.\n");
//Destroy device
device_destroy(hall_class, MKDEV(major_number, 0));
class_unregister(hall_class);
class_destroy(hall_class);
unregister_chrdev(major_number, DEVICE_NAME);
//Free IRQ and GPIO pin
free_irq(irq_num, NULL);
gpio_free(hall_gpio_pin);
printk(KERN_INFO "Hall Sensor: Driver exited.\n");
}
module_init(hall_init);
module_exit(hall_exit);
```
在编译之前,您还需要在Makefile中添加以下内容:
```makefile
obj-m += hall_sensor.o
```
将以上两个文件保存到同一个目录下,然后在该目录下打开终端,执行以下命令进行编译:
```bash
make -C /lib/modules/$(uname -r)/build M=$(pwd) modules
```
如果编译成功,将生成名为hall_sensor.ko的内核模块文件。将此文件插入到Linux系统中,即可使用Hall传感器。