| result | number | Yes | Authentication result obtained. For details, see [ResultCode](#resultcode8). |
| extraInfo | [AuthResult](#authresult8) | Yes | Extended information, which varies depending on the authentication result.<br>If the authentication is successful, the user authentication token will be returned in **extraInfo**.<br>If the authentication fails, the remaining number of authentication times will be returned in **extraInfo**.<br>If the authenticator is locked, the freeze time will be returned in **extraInfo**.|
| extraInfo | [AuthResult](#authresult8) | Yes | Extended information, which varies depending on the authentication result.<br>If the authentication is successful, the user authentication token will be returned in **extraInfo**.<br>If the authentication fails, the remaining number of authentication times will be returned in **extraInfo**.<br>If the authentication executor is locked, the freeze time will be returned in **extraInfo**.|
**Example**
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@@ -477,8 +477,8 @@ Obtains the tip code information during authentication. This function is optiona
- The pin, also called pin controller, manages pin resources of system on a chip (SoC) vendors and provides the pin multiplexing function.
- The pin module defines a set of common methods for managing pins, including:
- Obtaining or releasing the pin description handle: The kernel compares the pin name passed in with the pin names of each controller in the linked list. If a match is found, a pin description handle is obtained. After the operation on the pin is complete, the pin description handle will be released.
- Setting or obtaining the pull type of a pin: The pull type can be pull-up, pull-down, or floating.
- Setting or obtaining the pull strength of a pin: You can set the pull strength as required.
- Setting or obtaining the functions of a pin to implement pin multiplexing
### Basic Concepts<a name="section3"></a>
Pin, as a software concept, provides APIs for uniformly managing the pins from different SoC vendors, providing the pin multiplexing function, and configuring the electrical features of pins.
- SoC
An SOC is a chip that integrates microprocessors, analog IP cores, digital IP cores, and memory for specific purposes.
- Pin multiplexing
When the number of pins of a chip cannot handle the increasing connection requests, you can set the software registers to make the pins to work in different states.
### Working Principles<a name="section4"></a>
In the HDF, the pin module does not support the user mode and therefore does not need to publish services. It uses the service-free mode in interface adaptation. The service-free mode applies to the devices that do not provide user-mode APIs or the OS that does not distinguish the user mode and the kernel mode. The **DevHandle**, a void pointer, directly points to the kernel mode address of the device object.
The pin module is divided into the following layers:
- Interface layer: provides APIs for obtaining a pin, setting or obtaining the pull type, pull strength, and functions of a pin, and releasing a pin.
- Core layer: provides the capabilities of matching pin resources and adding, removing, and managing pin controllers. The core layer interacts with the adaptation layer by using hooks.
- Adaptation layer: instantiates hooks to implement specific functions.
Currently, the pin module supports only the kernels (LiteOS) of mini and small systems.
## Usage Guidelines<aname="section6"></a>
### When to Use<aname="7"></a>
The pin module is a software concept and is used to manage pin resources. You can set the functions, pull type, and pull strength of pins to implement pin multiplexing.
### Available APIs<a name="section8"></a>
The table below describes the APIs of the pin module. For more details, see API Reference.
>All APIs described in this document can be called only in the kernel space.
### How to Develop<a name="section9"></a>
The figure below shows the process.
**Figure 2** Process of using the pin module<aname="fig2"></a>
![](figures/process-of-using-pin.png"Process of using the pin module")
#### Obtaining the Pin Description Handle
Before performing an operation on a pin, call **PinGet** to obtain the pin description handle. This API returns the pin description handle that matches the input pin name.
```
DevHandle PinGet(const char *pinName);
```
**Table 2** Description of PinGet
<aname="table2"></a>
| Parameter | Description |
| ---------- | ----------------------- |
| pinName | Pointer to the pin name. |
| **Return Value**| **Description** |
| NULL | Failed to obtain the pin description handle.|
| strength | Pointer to the pull strength obtained.|
| **Return Value**| **Description** |
| 0 | The operation is successful. |
| Negative value | The operation fails. |
Example: Obtain the pull strength of a pin.
```
int32_t ret;
uint32_t strengthNum;
/* Obtain the pull strength of the pin. */
ret = PinGetStrength(handle, &strengthNum);
if (ret != HDF_SUCCESS) {
HDF_LOGE("PinGetStrength: failed, ret %d\n", ret);
return ret;
}
```
#### Setting the Pin Function
The pin function refers to the pin multiplexing function. The function of each pin is different. For details about the pin functions, see [pin_config.hcs](https://gitee.com/openharmony/device_soc_hisilicon/blob/master/hi3516dv300/sdk_liteos/hdf_config/pin/pin_config.hcs).
