linux内核虚拟i2c控制器驱动
❓ 问题描述:
编写一个虚拟i2c控制器驱动，实现i2c设备的模拟操作。
在驱动中进行i2c的读写操作一般有3种方式，如下:
内核中主要有三大类I2C通信方式，按抽象层次从低到高排列：
通用I2C消息传输 (Generic I2C Messaging): 这是最基础、最灵活的方式，可以实现任何I2C协议。
SMBus 协议函数: 针对遵循SMBus规范的设备，提供了一套简单易用的API。i2c_smbus_write_byte_data 就是其中之一。
Regmap API: 这是一个更高级的抽象层，它封装了I2C和SPI的寄存器访问，强烈推荐用于具有大量寄存器的复杂设备。
日志
添加打印日志信息分析步骤
第1步:
第2步:
...
代码片段
设备树
virt_i2c: i2c@0 {
compatible = "my-company,virt-i2c";
#address-cells = <1>;
#size-cells = <0>;
/* 在此虚拟总线上定义一个虚拟设备 */
virtual_eeprom: eeprom@50 {
compatible = "my-company,virt-dev";
reg = <0x50>; /* I2C 从设备地址 */
};
};
i2c控制器代码
// virt-i2c-bus.c
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/of.h>
#include <linux/slab.h>
#define VIRT_I2C_BUS_NAME "virt-i2c-bus"
#define VIRT_I2C_SLAVE_ADDR 0x50 // 虚拟设备的I2C地址
#define VIRT_I2C_REG_SIZE 256 // 虚拟设备有256字节的寄存器空间
// 私有数据结构，保存适配器和虚拟寄存器
struct virt_i2c_bus {
struct i2c_adapter adap;
struct i2c_algorithm algo;
struct device *dev;
u8 reg_data[VIRT_I2C_REG_SIZE]; // 模拟设备的内存
};
/*
struct i2c_msg {
__u16 addr; // 从设备地址
__u16 flags; // 标志位 (0 表明写,I2C_M_RD:1 表明读)
__u16 len; // 数据缓冲区长度
__u8 *buf; // 指向数据的指针
};
*/
// 核心功能：模拟I2C传输
static int virt_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
struct virt_i2c_bus *bus = i2c_get_adapdata(adap);
struct i2c_msg *msg;
int i, j;
unsigned int offset = 0;
pr_info("virt_i2c_xfer: num of msgs = %d
", num);
for (i = 0; i < num; i++) {
msg = &msgs[i];
// 检查是否是我们的虚拟从设备地址
if (msg->addr != VIRT_I2C_SLAVE_ADDR) {
pr_err("virt_i2c_xfer: invalid slave address 0x%02x
", msg->addr);
return -ENXIO; // No such device or address
}
if (msg->flags & I2C_M_RD) {
// --- 读操作 ---
pr_info("virt_i2c_xfer: Reading %d bytes from offset %u
", msg->len, offset);
if (offset + msg->len > VIRT_I2C_REG_SIZE) {
pr_err("virt_i2c_xfer: Read out of bounds
");
return -EIO;
}
memcpy(msg->buf, &bus->reg_data[offset], msg->len);
} else {
// --- 写操作 ---
// 常见的I2C设备协议：第一个字节是寄存器地址/偏移量
if (msg->len > 0) {
offset = msg->buf[0];
pr_info("virt_i2c_xfer: Writing %d bytes to offset %u
", msg->len - 1, offset);
if (offset + msg->len - 1 > VIRT_I2C_REG_SIZE) {
pr_err("virt_i2c_xfer: Write out of bounds
");
return -EIO;
}
// 将数据写入我们的虚拟寄存器
if (msg->len > 1) {
memcpy(&bus->reg_data[offset], &msg->buf[1], msg->len - 1);
}
// 打印写入的一些数据用于调试
for(j = 0; j < msg->len-1 && j < 8; j++) {
pr_info(" data[%d]=0x%02x", j, msg->buf[j+1]);
}
}
}
}
return num; // 返回成功处理的消息数量
}
static u32 virt_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static const struct i2c_algorithm virt_i2c_algo = {
.master_xfer = virt_i2c_xfer, // 实现I2C传输
.functionality = virt_i2c_func, // 实现I2C功能
};
static int virt_i2c_bus_probe(struct platform_device *pdev)
{
struct virt_i2c_bus *bus;
int ret;
int i;
bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
if (!bus)
return -ENOMEM;
bus->dev = &pdev->dev;
platform_set_drvdata(pdev, bus);
// 初始化虚拟寄存器 (例如，用递增的值填充)
for (i = 0; i < VIRT_I2C_REG_SIZE; i++) {
bus->reg_data[i] = i;
}
// 设置 i2c_adapter
bus->adap.owner = THIS_MODULE;
bus->adap.class = I2C_CLASS_HWMON; // 类别可以自选
/*i2cdetect -l 查看I2C总线编号和名称
例如：i2cdetect -l
i2c-2 i2c Virtual I2C Bus1 I2C adapter
*/
snprintf(bus->adap.name, sizeof(bus->adap.name), "Virtual I2C Bus");
bus->adap.algo = &virt_i2c_algo;
bus->adap.dev.parent = &pdev->dev;
bus->adap.dev.of_node = pdev->dev.of_node;
i2c_set_adapdata(&bus->adap, bus);
ret = i2c_add_adapter(&bus->adap);
if (ret) {
dev_err(&pdev->dev, "Failed to add virtual i2c adapter
");
return ret;
}
dev_info(&pdev->dev, "Virtual I2C adapter registered (bus %d)
", bus->adap.nr);
return 0;
}
static int virt_i2c_bus_remove(struct platform_device *pdev)
{
struct virt_i2c_bus *bus = platform_get_drvdata(pdev);
i2c_del_adapter(&bus->adap);
dev_info(&pdev->dev, "Virtual I2C adapter unregistered
");
return 0;
}
static const struct of_device_id virt_i2c_bus_of_match[] = {
{ .compatible = "my-company,virt-i2c" },
{ },
};
MODULE_DEVICE_TABLE(of, virt_i2c_bus_of_match);
static struct platform_driver virt_i2c_bus_driver = {
.driver = {
.name = VIRT_I2C_BUS_NAME,
.of_match_table = virt_i2c_bus_of_match,
},
.probe = virt_i2c_bus_probe,
.remove = virt_i2c_bus_remove,
};
module_platform_driver(virt_i2c_bus_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("A virtual I2C bus controller driver");
i2c测试程序 A) 实现一个简单的写操作 这个操作需要发送两个字节：寄存器地址 0x10 和数据 0xAB。
B) 实现一个读操作 这是一个典型的“组合消息”： 先发送一个“写”消息，内容是要读取的寄存器地址 (0x10)。 紧接着发送一个“读”消息，来接收数据。这两个操作之间没有STOP信号。
/*
* FilePath: drivers/i2c/virt-i2c-dev.c
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/i2c.h>
#include <linux/of.h>
#include <linux/slab.h> // for kzalloc/kfree
#include <linux/sysfs.h> // for sysfs
#include <linux/mutex.h> // for mutex
#include <linux/regmap.h>
#define TEST_REG_ADDR 0x10
#define TEST_VALUE 0xAB
// 1. 定义私有数据结构
struct virt_i2c_dev {
struct i2c_client *client;
struct mutex lock; // 保护对设备和last_val的并发访问
s32 last_val; // 存储上一次读/写的值
struct regmap *regmap; // <<< 新增: regmap 实例
};
static const struct regmap_config virt_i2c_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
// 我们的虚拟控制器没有更复杂的配置，所以保持简单
};
int my_regmap_write(struct virt_i2c_dev *priv, unsigned int reg_addr, unsigned int data)
{
return regmap_write(priv->regmap, reg_addr, data);
}
// <<< 新增: regmap 读函数
int my_regmap_read(struct virt_i2c_dev *priv, unsigned int reg_addr)
{
unsigned int data;
int ret;
ret = regmap_read(priv->regmap, reg_addr, &data);
if (ret < 0) {
dev_err(&priv->client->dev, "Failed to read from register 0x%02x
", reg_addr);
return ret;
}
return data;
}
int my_i2c_write(struct i2c_client *client, u8 reg_addr, u8 data) {
u8 buf[2];
struct i2c_msg msg;
buf[0] = reg_addr; // 寄存器地址
buf[1] = data; // 要写入的数据
msg.addr = client->addr; // 从设备地址
msg.flags = 0; // 标志位为0，表明写操作
msg.len = 2; // 我们要发送2个字节
msg.buf = buf; // 数据缓冲区
// 发送一个消息
if (i2c_transfer(client->adapter, &msg, 1) != 1) {
dev_err(&client->dev, "Failed to write using i2c_transfer
");
return -EIO;
}
return 0;
}
u8 my_i2c_read(struct i2c_client *client, u8 reg_addr) {
u8 read_val;
struct i2c_msg msgs[2];
// 消息1: 写寄存器地址
msgs[0].addr = client->addr;
msgs[0].flags = 0; // 写
msgs[0].len = 1;
msgs[0].buf = ®_addr;
// 消息2: 从该地址读取数据
msgs[1].addr = client->addr;
msgs[1].flags = I2C_M_RD; // 读
msgs[1].len = 1;
msgs[1].buf = &read_val;
// 执行包含2个消息的事务
if (i2c_transfer(client->adapter, msgs, 2) != 2) {
dev_err(&client->dev, "Failed to perform combined read
");
return -EIO;
}
return read_val;
}
// 2. 实现 'store' 函数 (处理 `echo "..." > i2c_access` )
static ssize_t i2c_access_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct virt_i2c_dev *priv = i2c_get_clientdata(client);
unsigned int reg, val;
char rw;
int ret;
// 解析输入: "w <reg> <val>" or "r <reg>"
if (sscanf(buf, "w %x %x", ®, &val) == 2) {
// --- 写操作 ---
dev_info(dev, "sysfs: Writing 0x%02x to register 0x%02x
", val, reg);
mutex_lock(&priv->lock);
// ret = my_i2c_write(client, reg, val);
// ret = i2c_smbus_write_byte_data(client, reg, val);
ret = my_regmap_write(priv, reg, val);
if (ret < 0) {
dev_err(dev, "sysfs: Failed to write to register 0x%02x
", reg);
mutex_unlock(&priv->lock);
return ret;
}
priv->last_val = val;
mutex_unlock(&priv->lock);
} else if (sscanf(buf, "r %x", ®) == 1) {
// --- 读操作 ---
dev_info(dev, "sysfs: Reading from register 0x%02x
", reg);
mutex_lock(&priv->lock);
//ret = my_i2c_read(client, reg);
// ret = i2c_smbus_read_byte_data(client, reg);
ret = my_regmap_read(priv, reg);
if (ret < 0) {
dev_err(dev, "sysfs: Failed to read from register 0x%02x
", reg);
mutex_unlock(&priv->lock);
return ret;
}
priv->last_val = ret;
mutex_unlock(&priv->lock);
dev_info(dev, "sysfs: Read value 0x%02x
", ret);
} else {
dev_err(dev, "Invalid format. Use 'w <reg> <val>' or 'r <reg>'
");
return -EINVAL;
}
return count; // 成功时返回消耗的字节数
}
// 3. 实现 'show' 函数 (处理 `cat i2c_access` )
static ssize_t i2c_access_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
struct virt_i2c_dev *priv = i2c_get_clientdata(client);
int ret;
mutex_lock(&priv->lock);
// 使用 scnprintf 格式化输出到用户缓冲区
ret = scnprintf(buf, PAGE_SIZE, "0x%02x
", priv->last_val);
mutex_unlock(&priv->lock);
return ret;
}
// 4. 使用 DEVICE_ATTR_RW 宏定义 sysfs 属性
// 它会自动创建 dev_attr_i2c_access 变量，并关联 show/store 函数
static DEVICE_ATTR_RW(i2c_access);
// probe 函数修改
static int virt_i2c_dev_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct virt_i2c_dev *priv;
s32 read_val;
int ret;
// 分配私有数据结构
priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->client = client;
mutex_init(&priv->lock);
i2c_set_clientdata(client, priv);
// 初始化 regmap
priv->regmap = devm_regmap_init_i2c(client, &virt_i2c_regmap_config);
if (IS_ERR(priv->regmap)) {
dev_err(&client->dev, "Failed to initialize regmap: %ld
",
PTR_ERR(priv->regmap));
return PTR_ERR(priv->regmap);
}
dev_info(&client->dev, "Probe called for virtual I2C device
");
// --- 原有的启动自检程序 (保留，用于确认驱动加载时基本功能正常) ---
dev_info(&client->dev, "--- Running probe self-test ---
");
read_val = i2c_smbus_read_byte_data(client, TEST_REG_ADDR);
if (read_val < 0) {
dev_err(&client->dev, "Self-test: Failed to read from reg 0x%x
", TEST_REG_ADDR);
return read_val;
}
dev_info(&client->dev, "Self-test: Initial value at reg 0x%x is 0x%02x
", TEST_REG_ADDR, read_val);
ret = i2c_smbus_write_byte_data(client, TEST_REG_ADDR, TEST_VALUE);
if (ret < 0) {
dev_err(&client->dev, "Self-test: Failed to write to reg 0x%x
", TEST_REG_ADDR);
return ret;
}
read_val = i2c_smbus_read_byte_data(client, TEST_REG_ADDR);
if (read_val == TEST_VALUE) {
dev_info(&client->dev, "Self-test: SUCCESS
");
} else {
dev_err(&client->dev, "Self-test: FAILURE
");
}
priv->last_val = read_val; // 初始化 last_val
dev_info(&client->dev, "--------------------------------
");
// 5. 创建 sysfs 文件
ret = device_create_file(&client->dev, &dev_attr_i2c_access);
if (ret) {
dev_err(&client->dev, "Failed to create sysfs file 'i2c_access'
");
// devm_kzalloc 会自动处理 priv 的释放，无需手动 kfree
return ret;
}
dev_info(&client->dev, "Sysfs attribute 'i2c_access' created.
");
return 0;
}
// remove 函数修改
static int virt_i2c_dev_remove(struct i2c_client *client)
{
// 6. 移除 sysfs 文件
device_remove_file(&client->dev, &dev_attr_i2c_access);
dev_info(&client->dev, "Sysfs attribute 'i2c_access' removed.
");
dev_info(&client->dev, "Virtual I2C device removed
");
return 0;
}
static const struct i2c_device_id virt_i2c_dev_id[] = {
{ "virt-dev", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, virt_i2c_dev_id);
static const struct of_device_id virt_i2c_dev_of_match[] = {
{ .compatible = "my-company,virt-dev" },
{ }
};
MODULE_DEVICE_TABLE(of, virt_i2c_dev_of_match);
static struct i2c_driver virt_i2c_dev_driver = {
.driver = {
.name = "virt-i2c-dev",
.of_match_table = virt_i2c_dev_of_match,
},
.probe = virt_i2c_dev_probe,
.remove = virt_i2c_dev_remove,
.id_table = virt_i2c_dev_id,
};
module_i2c_driver(virt_i2c_dev_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("Test client driver with sysfs support for the virtual I2C bus");
日志
/ko # insmod virt-i2c-bus.ko
virt-i2c-bus i2c@0: Virtual I2C adapter registered (bus 2)
/ko # i2cdetect -l
i2c-2 i2c Virtual I2C Bus I2C adapter
/ko # i2cdetect -r -y 2
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: 50 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
/ko # i2cdump -f -y 2 0x50
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
00: 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f .???????????????
10: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f ????????????????
20: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f !"#$%&'()*+,-./
30: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f 0123456789:;<=>?
40: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
50: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f PQRSTUVWXYZ[]^_
60: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f `abcdefghijklmno
70: 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f pqrstuvwxyz{|}~?
80: 80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f ????????????????
90: 90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f ????????????????
a0: a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af ????????????????
b0: b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf ????????????????
c0: c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf ????????????????
d0: d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df ????????????????
e0: e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef ????????????????
f0: f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff ???????????????.
/ko # dmesg -n 7
/ko # insmod virt-i2c-dev.ko
virt-i2c-dev 2-0050: Probe called for virtual I2C device
virt-i2c-dev 2-0050: --- Running probe self-test ---
virt_i2c_xfer: num of msgs = 2
virt_i2c_xfer: Writing 0 bytes to offset 16
virt_i2c_xfer: Reading 1 bytes from offset 16
virt-i2c-dev 2-0050: Self-test: Initial value at reg 0x10 is 0x10
virt_i2c_xfer: num of msgs = 1
virt_i2c_xfer: Writing 1 bytes to offset 16
data[0]=0xab
virt_i2c_xfer: num of msgs = 2
virt_i2c_xfer: Writing 0 bytes to offset 16
virt_i2c_xfer: Reading 1 bytes from offset 16
virt-i2c-dev 2-0050: Self-test: SUCCESS
virt-i2c-dev 2-0050: --------------------------------
virt-i2c-dev 2-0050: Sysfs attribute 'i2c_access' created.
查看下面有多少个设备
ls -al /sys/class/i2c-adapter/i2c-2/
total 0
drwxr-xr-x 5 root root 0 Jan 1 00:00 .
drwxr-xr-x 4 root root 0 Jan 1 00:00 ..
drwxr-xr-x 3 root root 0 Jan 1 00:00 2-0050
--w------- 1 root root 4096 Jan 1 00:04 delete_device
lrwxrwxrwx 1 root root 0 Jan 1 00:04 device -> ../../i2c@0
drwxr-xr-x 3 root root 0 Jan 1 00:00 i2c-dev
-r--r--r-- 1 root root 4096 Jan 1 00:04 name
--w------- 1 root root 4096 Jan 1 00:04 new_device
lrwxrwxrwx 1 root root 0 Jan 1 00:04 of_node -> ../../../../firmware/devicetree/base/i2c@0
drwxr-xr-x 2 root root 0 Jan 1 00:04 power
lrwxrwxrwx 1 root root 0 Jan 1 00:04 subsystem -> ../../../../bus/i2c
-rw-r--r-- 1 root root 4096 Jan 1 00:00 uevent
通过sys节点进行读写i2c设备
/sys # find ./ -name i2c_access
./devices/platform/i2c@0/i2c-2/2-0050/i2c_access
cd ./devices/platform/i2c@0/i2c-2/2-0050/
/sys/devices/platform/i2c@0/i2c-2/2-0050 # ls
driver modalias of_node subsystem
i2c_access name power uevent
/sys/devices/platform/i2c@0/i2c-2/2-0050 # echo 'w 30 ee' > i2c_access
virt-i2c-dev 2-0050: sysfs: Writing 0xee to register 0x30
virt_i2c_xfer: num of msgs = 1
virt_i2c_xfer: Writing 1 bytes to offset 48
data[0]=0xee/sys/devices/platform/i2c@0/i2c-2/2-0050 # echo 'r 30' > i2c_access
virt-i2c-dev 2-0050: sysfs: Reading from register 0x30
virt_i2c_xfer: num of msgs = 2
virt_i2c_xfer: Writing 0 bytes to offset 48
virt_i2c_xfer: Reading 1 bytes from offset 48
virt-i2c-dev 2-0050: sysfs: Read value 0xee
/sys/devices/platform/i2c@0/i2c-2/2-0050 # cat i2c_access
0xee
/sys/devices/platform/i2c@0/i2c-2/2-0050 # i2cdump -f -y 2 0x50
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
00: 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f .???????????????
10: ab 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f ????????????????
20: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f !"#$%&'()*+,-./
30: ee 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f ?123456789:;<=>?
40: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
50: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f PQRSTUVWXYZ[]^_
60: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f `abcdefghijklmno
70: 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f pqrstuvwxyz{|}~?
80: 80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f ????????????????
90: 90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f ????????????????
a0: a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af ????????????????
b0: b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf ????????????????
c0: c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf ????????????????
d0: d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df ????????????????
e0: e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef ????????????????
f0: f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff ???????????????.
图片
✅ 结论
输出结论
待查资料问题
- ❓ 问题 1：？
- ❓ 问题 2：？
参考链接
- 官方文档
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