@@ -107,7 +107,9 @@ The following example shows how to implement a distributed data object synchroni
});
}
}
local_object.on("change",this.changeCallback);
// To refresh the page in changeCallback, correctly set this.changeCallback.bind(this) in
changeCallback.
```
5. Modify object attributes. The object attributes support basic data types (such as number, Boolean, and string) and complex data types (array and nested basic types).
...
...
@@ -158,9 +160,9 @@ The following example shows how to implement a distributed data object synchroni
The sample code is as follows:
```js
// Unsubscribe from statusCallback.
// Unsubscribe from the online status change callback.
local_object.off("status",statusCallback);
// unsubscribe from all status change callbacks.
// Unsubscribe from all online status change callbacks.
local_object.off("status");
```
10. Remove a distributed data object from the synchronization network. After the distributed data object is removed from the network, the data changes on the local end will not be synchronized to the remote end.
...
...
@@ -169,7 +171,12 @@ The following example shows how to implement a distributed data object synchroni
```js
local_object.setSessionId("");
```
## Development Example
The following example is provided for you to better understand the development of distributed data object:
When an event occurs on a device, for example, a note is added, the tile or content of a note is changed, or the event list is cleared, the change will be synchronized to other devices in the trusted network by the Notepad app.
| fd | number | Yes | File descriptor of the file to read. |
| buffer | ArrayBuffer | Yes | Buffer used to store the file data read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. By default, data is read from the current position.|
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. By default, data is read from the current position.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size. |
- Return value
| Type | Description |
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...
@@ -662,7 +662,7 @@ Asynchronously reads data from a file. This method uses a callback to return the
| fd | number | Yes | File descriptor of the file to read. |
| buffer | ArrayBuffer | Yes | Buffer used to store the file data read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. By default, data is read from the current position.|
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. By default, data is read from the current position.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size. |
| callback | AsyncCallback<[ReadOut](#readout)> | Yes | Callback invoked when the data is read asynchronously. |
- Example
...
...
@@ -695,7 +695,7 @@ Synchronously reads data from a file.
| fd | number | Yes | File descriptor of the file to read. |
| buffer | ArrayBuffer | Yes | Buffer used to store the file data read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. By default, data is read from the current position.|
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. By default, data is read from the current position.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size. |
- Return value
| Type | Description |
...
...
@@ -867,7 +867,7 @@ Asynchronously writes data into a file. This method uses a promise to return the
| fd | number | Yes | File descriptor of the file to write. |
| buffer | ArrayBuffer \| string | Yes | Data to write. It can be a string or data from a buffer. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. The default value is **0**.<br>- **length** (number): length of the data to write. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. By default, data is written from the current position.<br>- **encoding** (string): format of the string to be encoded. The default value is **utf-8**, which is the only value supported.|
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. The default value is **0**.<br>- **length** (number): length of the data to write. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. By default, data is written from the current position.<br>- **encoding** (string): format of the string to be encoded. The default value is **utf-8**, which is the only value supported.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size.|
- Return value
| Type | Description |
...
...
@@ -903,7 +903,7 @@ Asynchronously writes data into a file. This method uses a callback to return th
| fd | number | Yes | File descriptor of the file to write. |
| buffer | ArrayBuffer \| string | Yes | Data to write. It can be a string or data from a buffer. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. The default value is **0**.<br>- **length** (number): length of the data to write. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. By default, data is written from the current position.<br>- **encoding** (string): format of the string to be encoded. The default value is **utf-8**, which is the only value supported.|
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. The default value is **0**.<br>- **length** (number): length of the data to write. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. By default, data is written from the current position.<br>- **encoding** (string): format of the string to be encoded. The default value is **utf-8**, which is the only value supported.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size.|
| callback | AsyncCallback<number> | Yes | Callback invoked when the data is written asynchronously. |
- Example
...
...
@@ -935,7 +935,7 @@ Synchronously writes data into a file.
| fd | number | Yes | File descriptor of the file to write. |
| buffer | ArrayBuffer \| string | Yes | Data to write. It can be a string or data from a buffer. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. The default value is **0**.<br>- **length** (number): length of the data to write. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. By default, data is written from the current position.<br>- **encoding** (string): format of the string to be encoded. The default value is **utf-8**, which is the only value supported.|
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. The default value is **0**.<br>- **length** (number): length of the data to write. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. By default, data is written from the current position.<br>- **encoding** (string): format of the string to be encoded. The default value is **utf-8**, which is the only value supported.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size.|
- Return value
| Type | Description |
...
...
@@ -961,7 +961,7 @@ Asynchronously calculates the hash value of a file. This method uses a promise t
| path | string | Yes | Absolute path of the target file. |
| algorithm | string | Yes | Algorithm used to calculate the hash value. The value can be **md5**, **sha1**, or **sha256**.**sha256** is recommended for security purposes.|
| algorithm | string | Yes | Algorithm used to calculate the hash value. The value can be **md5**, **sha1**, or **sha256**.<br/>**sha256** is recommended for security purposes.|
- Return value
| Type | Description |
...
...
@@ -990,7 +990,7 @@ Asynchronously calculates the hash value of a file. This method uses a callback
| path | string | Yes | Absolute path of the target file. |
| algorithm | string | Yes | Algorithm used to calculate the hash value. The value can be **md5**, **sha1**, or **sha256**.**sha256** is recommended for security purposes.|
| algorithm | string | Yes | Algorithm used to calculate the hash value. The value can be **md5**, **sha1**, or **sha256**.<br/>**sha256** is recommended for security purposes.|
| callback | AsyncCallback<string> | Yes | Callback used to return the hash value. The hash value is a hexadecimal string consisting of digits and uppercase letters.|
- Example
...
...
@@ -1472,10 +1472,10 @@ Asynchronously reads data from a file. This method uses a promise to return the
| buffer | ArrayBuffer | Yes | Buffer used to store the file data read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.|
| buffer | ArrayBuffer | Yes | Buffer used to store the file data read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size.|
- Return value
| Type | Description |
...
...
@@ -1509,7 +1509,7 @@ Asynchronously reads data from a file. This method uses a callback to return the
| buffer | ArrayBuffer | Yes | Buffer used to store the file data read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.|
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size.|
| callback | AsyncCallback<[ReadOut](#readout)> | Yes | Callback invoked when the data is read asynchronously from the file. |
- Example
...
...
@@ -2577,6 +2577,7 @@ Asynchronously stops **watcher**. This method uses a callback to return the resu
```
## Stream<sup>7+</sup>
File stream. Before calling a method of the **Stream** class, use the **createStream()** method synchronously or asynchronously to create a **Stream** instance.
...
...
@@ -2721,7 +2722,7 @@ Asynchronously writes data into the stream. This method uses a promise to return
| buffer | ArrayBuffer \| string | Yes | Data to write. It can be a string or data from a buffer. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. The default value is **0**.<br>- **length** (number): length of the data to write. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. By default, data is written from the current position.<br>- **encoding** (string): format of the string to be encoded. The default value is **utf-8**, which is the only value supported.|
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. The default value is **0**.<br>- **length** (number): length of the data to write. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. By default, data is written from the current position.<br>- **encoding** (string): format of the string to be encoded. The default value is **utf-8**, which is the only value supported.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size. |
- Return value
| Type | Description |
...
...
@@ -2753,11 +2754,11 @@ Asynchronously writes data into the stream. This method uses a callback to retur
| buffer | ArrayBuffer \| string | Yes | Data to write. It can be a string or data from a buffer. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. The default value is **0**.<br>- **length** (number): length of the data to write. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. By default, data is written from the current position.<br>- **encoding** (string): format of the string to be encoded. The default value is **utf-8**, which is the only value supported.|
| callback | AsyncCallback<number> | Yes | Callback invoked when the data is written asynchronously. |
| buffer | ArrayBuffer \| string | Yes | Data to write. It can be a string or data from a buffer. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. The default value is **0**.<br>- **length** (number): length of the data to write. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. By default, data is written from the current position.<br>- **encoding** (string): format of the string to be encoded. The default value is **utf-8**, which is the only value supported.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size.|
| callback | AsyncCallback<number> | Yes | Callback invoked when the data is written asynchronously. |
- Example
```js
...
...
@@ -2788,7 +2789,7 @@ Synchronously writes data into the stream.
| buffer | ArrayBuffer \| string | Yes | Data to write. It can be a string or data from a buffer. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. The default value is **0**.<br>- **length** (number): length of the data to write. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. By default, data is written from the current position.<br>- **encoding** (string): format of the string to be encoded. The default value is **utf-8**, which is the only value supported.|
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. The default value is **0**.<br>- **length** (number): length of the data to write. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. By default, data is written from the current position.<br>- **encoding** (string): format of the string to be encoded. The default value is **utf-8**, which is the only value supported.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size. |
- Return value
| Type | Description |
...
...
@@ -2818,7 +2819,7 @@ Asynchronously reads data from the stream. This method uses a promise to return
| buffer | ArrayBuffer | Yes | Buffer used to store the file read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. By default, data is read from the current position.|
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. By default, data is read from the current position.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size. |
- Return value
| Type | Description |
...
...
@@ -2853,7 +2854,7 @@ Asynchronously reads data from the stream. This method uses a callback to return
| buffer | ArrayBuffer | Yes | Buffer used to store the file read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. By default, data is read from the current position.|
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. By default, data is read from the current position.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size. |
| callback | AsyncCallback<[ReadOut](#readout)> | Yes | Callback invoked when data is read asynchronously from the stream. |
- Example
...
...
@@ -2884,7 +2885,7 @@ Synchronously reads data from the stream.
| buffer | ArrayBuffer | Yes | Buffer used to store the file read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. By default, data is read from the current position.|
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. The default value is **0**.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. By default, data is read from the current position.<br>- The sum of **offset** and **length** must be less than or equal to the buffer size. |
| options | [HuksOptions](#huksoptions) | Yes | Tags required for generating the key. |
| callback | AsyncCallback\<[HuksResult](#huksresult)> | Yes | Callback used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If any other result is returned, see **HuksResult**.|
| callback | AsyncCallback\<[HuksResult](#huksresult)> | Yes | Callback used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code defined in **HuksResult** will be returned.|
**Example**
...
...
@@ -402,7 +402,7 @@ huks.generateKey(keyAlias, options, function (err, data){});
| callback | AsyncCallback\<[HuksResult](#huksresult)> | Yes | Callback used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned. For details about the error codes, see **HuksResult**.|
| callback | AsyncCallback\<[HuksResult](#huksresult)> | Yes | Callback used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned.|
**Example**
...
...
@@ -480,7 +480,7 @@ huks.deleteKey(keyAlias, emptyOptions, function (err, data) {});
| keyAlias | string | Yes | Key alias, which is used to hold the key pair.|
| options | [HuksOptions](#huksoptions) | Yes | Tags required for the import and key pair to import.|
| callback | AsyncCallback\<[HuksResult](#huksresult)> | Yes | Callback used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned. For details about the error codes, see **HuksResult**.|
| callback | AsyncCallback\<[HuksResult](#huksresult)> | Yes | Callback used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned.|
**Example**
...
...
@@ -600,7 +600,7 @@ huks.importKey(keyAlias, options, function (err, data){});
| Promise\<[HuksResult](#huksresult)> | Promise used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned. For details about the error codes, see **HuksResult**.<br/>**outData** contains the public key exported.|
| Promise\<[HuksResult](#huksresult)> | Promise used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned. **outData** contains the public key exported.|
**Example**
...
...
@@ -724,7 +724,7 @@ var result = huks.exportKey(keyAlias, emptyOptions);
> - The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
> - The APIs of this module are system APIs and cannot be called by third-party applications.
> - API version 9 is a canary release for trial use. The APIs of this version may be unstable.
## Modules to Import
...
...
@@ -15,7 +15,7 @@ import storagestatistics from "@ohos.storageStatistics";
> - The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
> - The APIs of this module are system APIs and cannot be called by third-party applications.
> - The initial APIs of this module are supported since API version 9.
> - API version 9 is a canary release for trial use. The APIs of this version may be unstable.
@@ -246,7 +246,7 @@ The process of signing a HAP is as follows:
>
> For security purposes, the ECC algorithm is recommended for generating key pairs for application signing signatures. The RSA algorithm is not recommended.<br/>
> You are advised to place the HAP, profile, KS file **OpenHarmony.p12**, root CA certificate, intermediate CA certificate, and hapsigner in the same directory for easy operation.
> The **developtools_hapsigner/autosign/result/** directory has the following files:<br/>- OpenHarmony KS file **OpenHarmony.p12** <br/>- Root CA certificate **rootCA.cer**<br/>- Intermediate CA certificate **subCA.cer**<br/>- Profile signing certificate **OpenHarmonyProfileRelease.pem**
> The [**developtools_hapsigner/autosign/result**](https://gitee.com/openharmony/developtools_hapsigner/tree/master/autosign/result) directory has the following files:<br/>- OpenHarmony KS file **OpenHarmony.p12** <br/>- Root CA certificate **rootCA.cer**<br/>- Intermediate CA certificate **subCA.cer**<br/>- Profile signing certificate **OpenHarmonyProfileRelease.pem**
**1. Generate a key pair for the application signing certificate.**
Generally, a general-purpose input/output \(GPIO\) controller manages all GPIO pins by group. Each group of GPIO pins is associated with one or more registers. The GPIO pins are operated by reading data from and writing data to the registers.
A general-purpose input/output (GPIO) controller manages all GPIO pins by group. Each group of GPIO pins is associated with one or more registers. The GPIO controller manages the pins by reading data from and writing data to the registers.
The GPIO APIs define a set of standard functions for performing operations on GPIO pins, including:
- Setting the pin direction, which can be input or output \(High impedance is not supported currently.\)
- Reading and writing level values, which can be low or high
- Setting an interrupt service routine \(ISR\) function and interrupt trigger mode for a pin
- Enabling or disabling a pin interrupt
## Available APIs<a name="section589913442203"></a>
<tdclass="cellrowborder"valign="top"width="47.9%"headers="mcps1.2.4.1.3 "><pid="p59687710219"><aname="p59687710219"></a><aname="p59687710219"></a>Reads the level value of a GPIO pin.</p>
<tdclass="cellrowborder"valign="top"headers="mcps1.2.4.1.2 "><pid="p396814715219"><aname="p396814715219"></a><aname="p396814715219"></a>Writes the level value of a GPIO pin.</p>
<tdclass="cellrowborder"valign="top"width="47.9%"headers="mcps1.2.4.1.3 "><pid="p179682792111"><aname="p179682792111"></a><aname="p179682792111"></a>Sets the direction for a GPIO pin.</p>
<tdclass="cellrowborder"valign="top"headers="mcps1.2.4.1.2 "><pid="p39689792111"><aname="p39689792111"></a><aname="p39689792111"></a>Obtains the direction for a GPIO pin.</p>
<tdclass="cellrowborder"valign="top"width="47.9%"headers="mcps1.2.4.1.3 "><pid="p99693712113"><aname="p99693712113"></a><aname="p99693712113"></a>Sets the ISR function for a GPIO pin.</p>
<tdclass="cellrowborder"valign="top"headers="mcps1.2.4.1.2 "><pid="p1996916792114"><aname="p1996916792114"></a><aname="p1996916792114"></a>Cancels the setting of the ISR function for a GPIO pin.</p>
<tdclass="cellrowborder"valign="top"headers="mcps1.2.4.1.2 "><pid="p2969473216"><aname="p2969473216"></a><aname="p2969473216"></a>Enables a GPIO interrupt.</p>
<tdclass="cellrowborder"valign="top"headers="mcps1.2.4.1.2 "><pid="p19690710214"><aname="p19690710214"></a><aname="p19690710214"></a>Disables a GPIO interrupt.</p>
### Determining a GPIO Pin Number<a name="section370083272117"></a>
The method for converting GPIO pin numbers varies according to the GPIO controller model, parameters, and controller driver of different system on chips \(SoCs\).
- Hi3516DV300
A controller manages 12 groups of GPIO pins. Each group contains 8 GPIO pins.
GPIO pin number = GPIO group index \(0–11\) x Number of GPIO pins in each group \(8\) + Offset in the group
Example: GPIO number of GPIO10\_3 = 10 x 8 + 3 = 83
- Hi3518EV300
A controller manages 10 groups of GPIO pins. Each group contains 10 GPIO pins.
GPIO pin number = GPIO group index \(0–9\) x Number of GPIO pins in each group \(10\) + Offset in the group
Example: GPIO pin number of GPIO7\_3 = 7 x 10 + 3 = 73
### Using APIs to Operate GPIO Pins<a name="section13604050132118"></a>
- Set the direction for a GPIO pin.
Before performing read/write operations on a GPIO pin, call the following function to set the direction:
<td class="cellrowborder" valign="top" width="51.88%"><p id="p103124517618"><a name="p103124517618"></a><a name="p103124517618"></a>Succeeded in setting the direction for a GPIO pin.</p>
<td class="cellrowborder" valign="top" width="51.88%"><p id="p153121553610"><a name="p153121553610"></a><a name="p153121553610"></a>Failed to set the direction for a GPIO pin.</p>
</td>
</tr>
</tbody>
</table>
- Read or write the level value for a GPIO pin.
To read the level value of a GPIO pin, call the following function:
<td class="cellrowborder" valign="top" width="51.88%"><p id="p1931618337524"><a name="p1931618337524"></a><a name="p1931618337524"></a>Level value to write.</p>
<td class="cellrowborder" valign="top" width="51.459999999999994%"><p id="p11355551174619"><a name="p11355551174619"></a><a name="p11355551174619"></a>ISR function to set.</p>
<td class="cellrowborder" valign="top" width="51.459999999999994%"><p id="p559185784619"><a name="p559185784619"></a><a name="p559185784619"></a>Pointer to the parameters passed to the ISR function.</p>
<td class="cellrowborder" valign="top" width="51.459999999999994%"><p id="p180521812465"><a name="p180521812465"></a><a name="p180521812465"></a>Succeeded in setting the ISR function for a GPIO pin.</p>
<td class="cellrowborder" valign="top" width="51.459999999999994%"><p id="p18805141884611"><a name="p18805141884611"></a><a name="p18805141884611"></a>Failed to set the ISR function for a GPIO pin.</p>
<td class="cellrowborder" valign="top" width="50%"><p id="p4669164219"><a name="p4669164219"></a><a name="p4669164219"></a>Failed to disable a GPIO interrupt.</p>
</td>
</tr>
</tbody>
</table>
Example:
```
/* ISR function */
*/
int32_t MyCallBackFunc(uint16_t gpio, void *data)
{
HDF_LOGI("%s: gpio:%u interrupt service in! data=%p\n", __func__, gpio, data);
return 0;
}
int32_t ret;
/* Set the ISR function to MyCallBackFunc, the parameter to NULL, and the interrupt trigger mode to rising edge. */
ret = GpioSetIrq(3, OSAL_IRQF_TRIGGER_RISING, MyCallBackFunc, NULL);
if (ret != 0) {
HDF_LOGE("GpioSetIrq: failed, ret %d\n", ret);
return;
}
/* Enable an interrupt for GPIO3. */
ret = GpioEnableIrq(3);
if (ret != 0) {
HDF_LOGE("GpioEnableIrq: failed, ret %d\n", ret);
return;
}
/* Disable the interrupt for GPIO3. */
ret = GpioDisableIrq(3);
if (ret != 0) {
HDF_LOGE("GpioDisableIrq: failed, ret %d\n", ret);
return;
}
/* Cancel the ISR function for GPIO3. */
ret = GpioUnSetIrq(3);
if (ret != 0) {
HDF_LOGE("GpioUnSetIrq: failed, ret %d\n", ret);
return;
}
```
- Setting the pin direction, which can be input or output (high impedance is not supported currently)
- Reading and writing level values, which can be low or high
- Setting an interrupt service routine (ISR) function and interrupt trigger mode for a pin
- Enabling or disabling pin interrupts
## Available APIs
**Table 1** GPIO driver APIs
| Category| Description|
| -------- | -------- |
| GPIO read/write| - **GpioRead**: reads the pin level.<br>- **GpioWrite**: writes the pin level.|
| GPIO settings| - **GpioSetDir**: sets the pin direction.<br>- **GpioGetDir**: obtains the pin direction.|
| GPIO interrupt settings| - **GpioSetIrq**: sets the ISR function for a GPIO pin.<br>- **GpioUnsetIrq**: cancels the setting of the ISR function for a GPIO pin.<br>- **GpioEnableIrq**: enables interrupts for a pin.<br>- **GpioDisableIrq**: disables interrupts for a pin.|
> All APIs described in this document can be called only in the kernel space.
## Usage Guidelines
### How to Use
## Usage Example<a name="section25941262111"></a>
The figure below <xrefhref="#fig16151101653713"idp:producemode_text="auto"class="- topic/xref "id="xref5621703302"></xref> shows the general GPIO development process. In the APIs, a GPIO pin is specified by the pin number.
In this example, we test the interrupt trigger of a GPIO pin as follows: Set the ISR function for the pin, set the trigger mode to rising edge and failing edge, write high and low levels to the pin alternately to generate level fluctuation, and observe the execution of the ISR function.
**Figure 1** GPIO development process
Select an idle GPIO pin. This example uses a Hi3516D V300 development board and GPIO pin GPIO10\_3, which is numbered GPIO83.
You can select an idle GPIO pin based on the development board and schematic diagram.
### Determining the GPIO Pin Number
The method for determining the GPIO pin number varies depending on the GPIO controller model, parameters, and controller driver of the system on chip (SoC).
- Hi3516DV300
A controller manages 12 groups of GPIO pins. Each group contains 8 GPIO pins. The group index ranges from 0 to 11.
GPIO pin number = GPIO group index x Number of GPIO pins in each group + Offset in the group
Example: GPIO number of GPIO10_3 = 10 x 8 + 3 = 83
- Hi3518EV300
A controller manages 10 groups of GPIO pins. Each group contains 10 GPIO pins. The group index ranges from 0 to 9.
GPIO pin number = GPIO group index x Number of GPIO pins in each group + Offset in the group
Example: GPIO pin number of GPIO7_3 = 7 x 10 + 3 = 73
### Using APIs to Operate GPIO Pins
- Set the GPIO pin direction.
Before performing read/write operations on a GPIO pin, call **GpioSetDir** to set the pin direction.
int32_t GpioSetDir(uint16_t gpio, uint16_t dir);
**Table 2** Description of GpioSetDir
| **Parameter**| **Description**|
| -------- | -------- |
| gpio | GPIO pin number.|
| dir | Direction to set.|
| **Return Value**| **Description**|
| 0 | The operation is successful.|
| Negative value| The operation failed.|
- Read or write the pin level.
Call **GpioRead** to read the level of a GPIO pin.
int32_t GpioRead(uint16_t gpio, uint16_t \*val);
**Table 3** Description of GpioRead
| **Parameter**| **Description**|
| -------- | -------- |
| gpio | GPIO pin number.|
| val | Pointer to the level value to read.|
| **Return Value**| **Description**|
| 0 | The operation is successful.|
| Negative value| The operation failed.|
Call **GpioWrite** to write the level value for a GPIO pin.
int32_t GpioWrite(uint16_t gpio, uint16_t val);
**Table 4** Description of GpioWrite
| **Parameter**| **Description**|
| -------- | -------- |
| gpio | GPIO pin number.|
| val | Level value to write.|
| **Return Value**| **Description**|
| 0 | The operation is successful.|
| Negative value| The operation failed.|
Sample code:
```
int32_t ret;
uint16_t val;
/* Set the direction of GPIO pin 3 to output. */
ret = GpioSetDir(3, GPIO_DIR_OUT);
if (ret != 0) {
HDF_LOGE("GpioSerDir: failed, ret %d\n", ret);
return;
}
/* Write the low level GPIO_VAL_LOW for GPIO pin 3. */
ret = GpioWrite(3, GPIO_VAL_LOW);
if (ret != 0) {
HDF_LOGE("GpioWrite: failed, ret %d\n", ret);
return;
}
/* Set the direction of GPIO pin 6 to input. */
ret = GpioSetDir(6, GPIO_DIR_IN);
if (ret != 0) {
HDF_LOGE("GpioSetDir: failed, ret %d\n", ret);
return;
}
/* Read the level value of GPIO pin 6. */
ret = GpioRead(6, &val);
```
- Set the ISR function for a GPIO pin.
Call **GpioSetIrq** to set the ISR function for a GPIO pin.
> The configured ISR function can be responded only after interrupts are enabled for the GPIO pin.
You can call **GpioDisableIrq** to disable interrupts for the pin.
int32_t GpioDisableIrq(uint16_t gpio);
**Table 8** Description of GpioDisableIrq
| **Parameter**| **Description**|
| -------- | -------- |
| gpio | GPIO pin number.|
| **Return Value**| **Description**|
| 0 | The operation is successful.|
| Negative value| The operation failed.|
Sample code:
```
/* ISR function */
int32_t MyCallBackFunc(uint16_t gpio, void *data)
{
HDF_LOGI("%s: gpio:%u interrupt service in! data=%p\n", __func__, gpio, data);
return 0;
}
int32_t ret;
/* Set the ISR function to MyCallBackFunc, with input parameter of NULL and the interrupt trigger mode of rising edge. */
ret = GpioSetIrq(3, OSAL_IRQF_TRIGGER_RISING, MyCallBackFunc, NULL);
if (ret != 0) {
HDF_LOGE("GpioSetIrq: failed, ret %d\n", ret);
return;
}
/* Enable interrupts for GPIO pin 3. */
ret = GpioEnableIrq(3);
if (ret != 0) {
HDF_LOGE("GpioEnableIrq: failed, ret %d\n", ret);
return;
}
/* Disable interrupts for GPIO pin 3. */
ret = GpioDisableIrq(3);
if (ret != 0) {
HDF_LOGE("GpioDisableIrq: failed, ret %d\n", ret);
return;
}
/* Cancel the ISR function for GPIO pin 3. */
ret = GpioUnsetIrq(3, NULL);
if (ret != 0) {
HDF_LOGE("GpioUnSetIrq: failed, ret %d\n", ret);
return;
}
```
## Example
The following example shows how to trigger an interrupt for a GPIO pin. The procedure is as follows:
1. Select an idle GPIO pin. This example uses a Hi3516D V300 development board and pin GPIO10_3 as an example. The pin number of GPIO10_3 is 83. You can select an idle GPIO pin as required.
2. Set an ISR function.
3. Set the interrupt trigger mode to edge triggering, and enable high and low levels to be written to the pin alternately to trigger the interrupt.
