update doc

Signed-off-by: Nshawn_he <shawn.he@huawei.com>

en/application-dev/reference/apis/js-apis-power.md

 # Power Manager
 
-> ![icon-note.gif](public_sys-resources/icon-note.gif) **NOTE**
-> The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.
-
 The Power Manager module provides APIs for rebooting and shutting down the system, as well as querying the screen status.
 
+> **NOTE**<br>
+> The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.
+
 
 ## Modules to Import
 
@@ -12,10 +12,6 @@ The Power Manager module provides APIs for rebooting and shutting down the syste
 import power from '@ohos.power';
 ```
 
-## System Capability
-
-SystemCapability.PowerManager.PowerManager.Core
-
 
 ## power.shutdownDevice
 
@@ -27,6 +23,8 @@ This is a system API and cannot be called by third-party applications.
 
 **Required permission**: ohos.permission.REBOOT
 
+**System capability:** SystemCapability.PowerManager.PowerManager.Core
+
 **Parameters**
 
 | Name   | Type    | Mandatory  | Description   |
@@ -47,7 +45,9 @@ rebootDevice(reason: string): void
 
 Reboots the system.
 
-**Required permission**: ohos.permission.REBOOT (to reboot) or ohos.permission.REBOOT_RECOVERY (to reboot and enter the recovery or updater mode)
+**Required permission**: ohos.permission.REBOOT
+
+**System capability:** SystemCapability.PowerManager.PowerManager.Core
 
 **Parameters**
 
@@ -69,6 +69,8 @@ isScreenOn(callback: AsyncCallback&lt;boolean&gt;): void
 
 Checks the screen status of the current device.
 
+**System capability:** SystemCapability.PowerManager.PowerManager.Core
+
 **Parameters**
 
 | Name     | Type                          | Mandatory  | Description                                      |
@@ -94,6 +96,8 @@ isScreenOn(): Promise&lt;boolean&gt;
 
 Checks the screen status of the current device.
 
+**System capability:** SystemCapability.PowerManager.PowerManager.Core
+
 **Return value**
 | Type                    | Description                                     |
 | ---------------------- | --------------------------------------- |
@@ -110,3 +114,182 @@ power.isScreenOn()
     console.log('error: ' + error);
 })
 ```
+
+## power.wakeupDevice<sup>9+</sup>
+
+wakeupDevice(detail: string): void
+
+Wakes up a device.
+
+This is a system API and cannot be called by third-party applications.
+
+**System capability:** SystemCapability.PowerManager.PowerManager.Core
+
+**Parameters**
+
+| Name| Type  | Mandatory| Description      |
+| ------ | ------ | ---- | ---------- |
+| detail | string | Yes  | Reason for wakeup.|
+
+**Example**
+
+```js
+power.wakeupDevice("application");
+console.info('power_wakeup_device_test success')
+```
+
+## power.suspendDevice<sup>9+</sup>
+
+suspendDevice(): void
+
+Hibernates a device.
+
+This is a system API and cannot be called by third-party applications.
+
+**System capability:** SystemCapability.PowerManager.PowerManager.Core
+
+**Example**
+
+```js
+power.suspendDevice();
+console.info('power_suspend_device_test success')
+```
+
+## power.getPowerMode<sup>9+</sup>
+
+getPowerMode(callback: AsyncCallback&lt;DevicePowerMode&gt;): void
+
+Obtains the power mode of this device.
+
+**Required permission**: ohos.permission.POWER_OPTIMIZATION
+
+**System capability:** SystemCapability.PowerManager.PowerManager.Core
+
+**Parameters**
+
+| Name  | Type                                | Mandatory| Description                                                        |
+| -------- | ------------------------------------ | ---- | ------------------------------------------------------------ |
+| callback | AsyncCallback&lt;DevicePowerMode&gt; | Yes  | Callback used to obtain the return value.<br>Return value: [DevicePowerMode](#devicepowermode9)|
+
+**Example**
+
+```js
+power.getPowerMode((error, mode) => {
+    if (typeof error === "undefined") {
+        console.info('power mode is ' + mode);
+    } else {
+        console.log('error: ' + error);
+    }
+})
+```
+
+
+## power.getPowerMode<sup>9+</sup>
+
+getPowerMode(): Promise&lt;DevicePowerMode&gt;
+
+Obtains the power mode of this device.
+
+**Required permission**: ohos.permission.POWER_OPTIMIZATION
+
+**System capability:** SystemCapability.PowerManager.PowerManager.Core
+
+**Return value**
+
+| Type                          | Description                                                        |
+| ------------------------------ | ------------------------------------------------------------ |
+| Promise&lt;DevicePowerMode&gt; | Promise used to obtain the return value. <br/>Return value: [DevicePowerMode](#devicepowermode9)|
+
+**Example**
+
+```js
+power.getPowerMode()
+.then(mode => {
+    console.info('power mode is ' + mode);
+})
+.catch(error => {
+    console.log('error: ' + error);
+})
+```
+
+## power.setPowerMode<sup>9+</sup>
+
+setPowerMode(mode: DevicePowerMode, callback: AsyncCallback&lt;void&gt;): void
+
+Sets the power mode of this device.
+
+This is a system API and cannot be called by third-party applications.
+
+**Required permission**: ohos.permission.POWER_OPTIMIZATION
+
+**System capability:** SystemCapability.PowerManager.PowerManager.Core
+
+**Parameters**
+
+| Name  | Type                                | Mandatory| Description                    |
+| -------- | ------------------------------------ | ---- | ------------------------ |
+| mode     | [DevicePowerMode](#devicepowermode9) | Yes  | Power mode.              |
+| callback | AsyncCallback&lt;void&gt;            | Yes  | Callback used to return the result.|
+
+**Example**
+
+```js
+power.setPowerMode(power.DevicePowerMode.MODE_PERFORMANCE, error => {
+    if (typeof error === "undefined") {
+        console.info('set power mode to MODE_PERFORMANCE');
+    } else {
+        console.log('error: ' + error);
+    }
+})
+```
+
+
+## power.setPowerMode<sup>9+</sup>
+
+setPowerMode(mode: DevicePowerMode): Promise&lt;void&gt;
+
+Sets the power mode of this device.
+
+This is a system API and cannot be called by third-party applications.
+
+**Required permission**: ohos.permission.POWER_OPTIMIZATION
+
+**System capability:** SystemCapability.PowerManager.PowerManager.Core
+
+**Parameters**
+
+| Name| Type                                | Mandatory| Description      |
+| ------ | ------------------------------------ | ---- | ---------- |
+| mode   | [DevicePowerMode](#devicepowermode9) | Yes  | Power mode.|
+
+**Return value**
+
+| Type               | Description         |
+| ------------------- | ------------- |
+| Promise&lt;void&gt; | Promise used to return the result.|
+
+**Example**
+
+```js
+power.setPowerMode(power.DevicePowerMode.MODE_PERFORMANCE)
+.then(() => {
+    console.info('set power mode to MODE_PERFORMANCE');
+})
+.catch(error => {
+    console.log('error: ' + error);
+})
+```
+
+## DevicePowerMode<sup>9+</sup>
+
+Enumerates power modes.
+
+**System capability:** SystemCapability.PowerManager.PowerManager.Core
+
+
+| Name                   | Default Value| Description                  |
+| ----------------------- | ------ | ---------------------- |
+| MODE_NORMAL             | 600    | Standard mode. It is the default value.|
+| MODE_POWER_SAVE         | 601    | Power saving mode.        |
+| MODE_PERFORMANCE        | 602    | Performance mode.        |
+| MODE_EXTREME_POWER_SAVE | 603    | Ultra power saving mode.    |