C180_oyster_driver/fan.c

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/i2c.h>
#include <linux/acpi.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/poll.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include "light_ring.h"

#define DEVICE_NAME "fan"
#define CLASS_NAME "fan_class"
#define DRIVER_NAME "fan_driver"

struct fan_dev
{
    struct cdev cdev;
    dev_t devt;
    struct class *class;
    struct device *device;
};

extern struct kobject *vfiec_kobj;
static struct kobject *fan_kobj = NULL;
static int major = 0; // 主设备号（0表示动态分配）
static struct fan_dev *fan_dev_device = NULL;
static dev_t dev_num;

// 文件打开
static int fan_open(struct inode *inode, struct file *filp)
{
    // 从inode获取cdev，再获取包含cdev的结构体
    struct fan_dev *dev = container_of(inode->i_cdev, struct fan_dev, cdev);
    filp->private_data = dev; // 保存到file结构供其他函数使用

    printk(KERN_INFO "fan: device opened\n");
    return 0;
}

// 文件释放
static int fan_release(struct inode *inode, struct file *filp)
{
    printk(KERN_INFO "fan: device closed\n");
    return 0;
}

// 读操作
static ssize_t fan_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos)
{
    struct fan_dev *dev = filp->private_data;
    return count;
}

// 写操作
static ssize_t fan_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos)
{
    struct fan_dev *dev = filp->private_data;

    printk(KERN_INFO "fan: wrote %zu bytes\n", count);
    return count;
}

// 文件操作结构体
static struct file_operations fan_fops = {
    .owner = THIS_MODULE,
    .open = fan_open,
    .release = fan_release,
    .read = fan_read,
    .write = fan_write,
};

static ssize_t fan1_input_show(struct kobject *kobj, struct kobj_attribute *attr,
                               char *buf)
{
    static int count = 0;
    count++;

    return sprintf(buf, "fan1_input_show count=%d\n", count);
}

static ssize_t fan1_input_store(struct kobject *kobj, struct kobj_attribute *attr,
                                const char *buf, size_t count)
{
    printk("fan1_input_store kernel rev:%s\n", buf);
    return count;
}

static ssize_t fan2_input_show(struct kobject *kobj, struct kobj_attribute *attr,
                               char *buf)
{
    static int count = 0;
    count++;

    return sprintf(buf, "fan2_input_show count=%d\n", count);
}

static ssize_t fan2_input_store(struct kobject *kobj, struct kobj_attribute *attr,
                                const char *buf, size_t count)
{
    printk("fan2_input_store kernel rev:%s\n", buf);
    return count;
}

static ssize_t pwm1_show(struct kobject *kobj, struct kobj_attribute *attr,
                         char *buf)
{
    static int count = 0;
    count++;

    return sprintf(buf, "pwm1_show count=%d\n", count);
}

static ssize_t pwm1_store(struct kobject *kobj, struct kobj_attribute *attr,
                          const char *buf, size_t count)
{
    printk("pwm1_store kernel rev:%s\n", buf);
    return count;
}

static ssize_t pwm1_enable_show(struct kobject *kobj, struct kobj_attribute *attr,
                                char *buf)
{
    static int count = 0;
    count++;

    return sprintf(buf, "pwm1_enable_show count=%d\n", count);
}

static ssize_t pwm1_enable_store(struct kobject *kobj, struct kobj_attribute *attr,
                                 const char *buf, size_t count)
{
    printk("pwm1_enable_store kernel rev:%s\n", buf);
    return count;
}

static ssize_t pwm2_show(struct kobject *kobj, struct kobj_attribute *attr,
                         char *buf)
{
    static int count = 0;
    count++;

    return sprintf(buf, "pwm2_show count=%d\n", count);
}

static ssize_t pwm2_store(struct kobject *kobj, struct kobj_attribute *attr,
                          const char *buf, size_t count)
{
    printk("pwm2_store kernel rev:%s\n", buf);
    return count;
}

static ssize_t pwm2_enable_show(struct kobject *kobj, struct kobj_attribute *attr,
                                char *buf)
{
    static int count = 0;
    count++;

    return sprintf(buf, "pwm2_enable_show count=%d\n", count);
}

static ssize_t pwm2_enable_store(struct kobject *kobj, struct kobj_attribute *attr,
                                 const char *buf, size_t count)
{
    printk("pwm2_enable_store kernel rev:%s\n", buf);
    return count;
}

static ssize_t voltage_5v_show(struct kobject *kobj, struct kobj_attribute *attr,
                                char *buf)
{
    static int count = 0;
    count++;

    return sprintf(buf, "voltage_5v_show count=%d\n", count);
}

static ssize_t voltage_5v_store(struct kobject *kobj, struct kobj_attribute *attr,
                                 const char *buf, size_t count)
{
    printk("voltage_5v_store kernel rev:%s\n", buf);
    return count;
}

static ssize_t voltage_12v_show(struct kobject *kobj, struct kobj_attribute *attr,
                                char *buf)
{
    static int count = 0;
    count++;

    return sprintf(buf, "voltage_12v_show count=%d\n", count);
}

static ssize_t voltage_12v_store(struct kobject *kobj, struct kobj_attribute *attr,
                                 const char *buf, size_t count)
{
    printk("voltage_12v_store kernel rev:%s\n", buf);
    return count;
}

static ssize_t voltage_vcore_show(struct kobject *kobj, struct kobj_attribute *attr,
                                char *buf)
{
    static int count = 0;
    count++;

    return sprintf(buf, "voltage_vcore_show count=%d\n", count);
}

static ssize_t voltage_vcore_store(struct kobject *kobj, struct kobj_attribute *attr,
                                 const char *buf, size_t count)
{
    printk("voltage_vcore_store kernel rev:%s\n", buf);
    return count;
}

static ssize_t ac_power_show(struct kobject *kobj, struct kobj_attribute *attr,
                                char *buf)
{
    static int count = 0;
    count++;

    return sprintf(buf, "ac_power_show count=%d\n", count);
}

static ssize_t ac_power_store(struct kobject *kobj, struct kobj_attribute *attr,
                                 const char *buf, size_t count)
{
    printk("ac_power_store kernel rev:%s\n", buf);
    return count;
}

static ssize_t power_flag_show(struct kobject *kobj, struct kobj_attribute *attr,
                                char *buf)
{
    static int count = 0;
    count++;

    return sprintf(buf, "power_flag_show count=%d\n", count);
}

static ssize_t power_flag_store(struct kobject *kobj, struct kobj_attribute *attr,
                                 const char *buf, size_t count)
{
    printk("power_flag_store kernel rev:%s\n", buf);
    return count;
}

static struct kobj_attribute fan1_input =
    __ATTR(fan1_input, 0644, fan1_input_show, fan1_input_store);

static struct kobj_attribute fan2_input =
    __ATTR(fan2_input, 0644, fan2_input_show, fan2_input_store);

static struct kobj_attribute pwm1 =
    __ATTR(pwm1, 0644, pwm1_show, pwm1_store);

static struct kobj_attribute pwm1_enable =
    __ATTR(pwm1_enable, 0644, pwm1_enable_show, pwm1_enable_store);

static struct kobj_attribute pwm2 =
    __ATTR(pwm2, 0644, pwm2_show, pwm2_store);

static struct kobj_attribute pwm2_enable =
    __ATTR(pwm2_enable, 0644, pwm2_enable_show, pwm2_enable_store);

static struct kobj_attribute voltage_5v =
    __ATTR(voltage_5v, 0644, voltage_5v_show, voltage_5v_store);

static struct kobj_attribute voltage_12v =
    __ATTR(voltage_12v, 0644, voltage_12v_show, voltage_12v_store);

static struct kobj_attribute voltage_vcore =
    __ATTR(voltage_vcore, 0644, voltage_vcore_show, voltage_vcore_store);

static struct kobj_attribute ac_power =
    __ATTR(ac_power, 0644, ac_power_show, ac_power_store);

static struct kobj_attribute power_flag =
    __ATTR(power_flag, 0644, power_flag_show, power_flag_store);

/* ==================== 属性组 ==================== */
static struct attribute *fan_attrs[] = {
    &fan1_input.attr,
    &fan2_input.attr,
    &pwm1.attr,
    &pwm1_enable.attr,
    &pwm2.attr,
    &pwm2_enable.attr,
    &voltage_5v.attr,
    &voltage_12v.attr,
    &voltage_vcore.attr,
    &ac_power.attr,
    &power_flag.attr,
    NULL,
};

static struct attribute_group fan_attr_group = {
    .attrs = fan_attrs,
};

int fan_init(void)
{
    int ret;
    /* 创建 /sys/kernel/vfiec/lightring */
    fan_kobj = kobject_create_and_add("hwmon", vfiec_kobj);
    if (!fan_kobj)
    {
        ret = -ENOMEM;
    }
    else
    {
        printk(KERN_INFO "Faifan to create sysfs node\n");
    }

    /* 创建属性文件 */
    ret = sysfs_create_group(fan_kobj, &fan_attr_group);
    if (ret)
    {
        pr_err("Faifan to create sysfs group: %d\n", ret);
        goto free_fan_kobj;
    }
    else
    {
        printk(KERN_INFO "Create sysfs group success\n");
    }

    ret = alloc_chrdev_region(&dev_num, 0, 1, DEVICE_NAME);
    if (ret < 0)
    {
        printk(KERN_ALERT "mychar: Failed to allocate device number\n");
        goto free_group;
    }

    major = MAJOR(dev_num);
    printk(KERN_INFO "mychar: Assigned major number %d\n", major);
    // 2. 分配设备结构体内存
    fan_dev_device = kzalloc(sizeof(struct fan_dev), GFP_KERNEL);
    if (!fan_dev_device)
    {
        printk(KERN_ALERT "mychar: Failed to allocate device memory\n");
        ret = -ENOMEM;
        goto free_chrdev;
    }

    cdev_init(&fan_dev_device->cdev, &fan_fops);
    fan_dev_device->cdev.owner = THIS_MODULE;
    ret = cdev_add(&fan_dev_device->cdev, dev_num, 1);
    if (ret < 0)
    {
        printk(KERN_ALERT "mychar: Failed to add cdev\n");
        goto free_fan_devices;
    }

    // 4. 创建设备类（用于自动创建/dev节点）
    fan_dev_device->class = class_create(THIS_MODULE, CLASS_NAME);
    if (IS_ERR(fan_dev_device->class))
    {
        printk(KERN_ALERT "mychar: Failed to create class\n");
        goto free_cdev_del;
    }

    // 5. 创建设备节点（会在/dev下生成）
    fan_dev_device->device = device_create(fan_dev_device->class, NULL, dev_num, NULL, DEVICE_NAME);
    if (IS_ERR(fan_dev_device->device))
    {
        printk(KERN_ALERT "mychar: Failed to create device\n");
        goto free_class;
    }
    return 0;
free_class:
    class_destroy(fan_dev_device->class);
free_cdev_del:
    cdev_del(&fan_dev_device->cdev);
free_fan_devices:
    kfree(fan_dev_device);
free_chrdev:
    unregister_chrdev_region(dev_num, 1);
free_group:
    sysfs_remove_group(fan_kobj, &fan_attr_group);
free_fan_kobj:
    kobject_put(fan_kobj);
    return ret;
}

void fan_exit(void)
{
    device_destroy(fan_dev_device->class, dev_num);
    class_destroy(fan_dev_device->class);
    cdev_del(&fan_dev_device->cdev);
    kfree(fan_dev_device);
    unregister_chrdev_region(dev_num, 1);
    sysfs_remove_group(fan_kobj, &fan_attr_group);
    kobject_put(fan_kobj);
}