linux 创建sysfs节点示例_linux sysfs节点设为explicitly labeled-优快云博客

此博客展示了一段Linux内核模块的代码，包含设备属性的显示与存储函数定义，如node1_show、node2_show和node1_store等。还定义了属性组，在初始化函数中创建并添加kobject，创建sysfs组，最后给出模块的初始化、退出函数及相关许可和作者信息。

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#include <linux/module.h>
#include <linux/slab.h>
#include <linux/kobject.h>
#include <linux/platform_device.h>

static ssize_t node1_show(struct device *dev,
       struct device_attribute *attr, char *buf)
{
   ssize_t rc = 0;
   snprintf(buf, 32, "%s\n", node1_value);
   rc = strlen(buf);
   return rc;
}

static ssize_t node2_show(struct device *dev,
       struct device_attribute *attr, char *buf)
{
   ssize_t rc = 0;
   snprintf(buf, 8, "%d\n", node2_value);
   rc = strlen(buf);
   return rc;
}

static ssize_t node1_store(struct device *dev,
       struct device_attribute *attr, const char *buf, size_t count)
{
   printk("buf = %s,echo debug buf",buf);

   return count;
}

static DEVICE_ATTR(node1, 0666, node1_show, node1_store);
static DEVICE_ATTR(node2, 0666, node2_show, NULL);

static struct attribute *all_node_attrs[] = {
       &dev_attr_node1.attr,
       &dev_attr_node2.attr,
       ....
       NULL
};

static struct attribute_group all_node_attr_group = {
.attrs = all_node_attrs,
};

int32_t example_init(void)
{
int32_t rc = 0;
struct kobject *all_node_device = NULL;

CDBG("%s %d\n", __func__, __LINE__);

node1_value = 0;
node2_value= 0;

   all_node_device = kobject_create_and_add("temp_node", NULL);
   if (all_node_device == NULL) {
       pr_err("%s: subsystem_register failed\n", __func__);
       rc = -ENOMEM;
       return rc;
   }
   rc = sysfs_create_group(all_node_device, &all_node_attr_group);
   if (rc) {
       pr_err("%s: sysfs_create_file failed\n", __func__);
       kobject_del(all_node_device);
   }

return 0;
}

static void __exit example_exit(void)
{
kobject_put(all_node_device);
}

module_init(example_init);
module_exit(example_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("xxxx")