Thermal Control Customization

Overview

Introduction

By default, OpenHarmony provides the thermal control feature. If a device becomes overheated during usage, thermal control measures need to be taken for the device. For example, if the battery temperature is too high during charging, then thermal control needs to be applied to the charging device. However, thermal control varies according to product specifications. To address this issue, OpenHarmony provides the thermal control customization function.

Constraints

The configuration path for battery level customization is subject to the configuration policy. In this development guide, /vendor is used as an example of the configuration path. During actual development, you need to modify the customization path based on the product configuration policy.

How to Develop

Setting Up the Environment

Hardware requirements:

Development board running the standard system, for example, the DAYU200 or Hi3516D V300 open source suite.

Environment requirements:

For details about the requirements on the Linux environment, see Quick Start.

Getting Started with Development

The following uses DAYU200 as an example to illustrate thermal control customization.

Create the thermal folder in the product directory /vendor/hihope/rk3568.
Create a target folder by referring to the default thermal control configuration folder, and install it in //vendor/hihope/rk3568/thermal. The content is as follows:
```
profile
├── BUILD.gn
├── thermal_service_config.xml
```

Write the custom thermal_service_config.xml file by referring to the thermal_service_config.xml file in the default thermal control configuration folder. The following table describes the related configuration items.

Table 1 Configuration items for thermal control

Configuration Item	Description	Parameter	Parameter Description	Data Type	Value Range
name="airplane"	Airplane mode control	N/A	N/A	N/A	N/A
name="cpu_big"	Big-core CPU control (big-core CPU frequency)	N/A	N/A	N/A	N/A
name="cpu_med"	Medium-core CPU control (medium-core CPU frequency)	N/A	N/A	N/A	N/A
name="cpu_lit"	Small-core CPU control (small-core CPU frequency)	N/A	N/A	N/A	N/A
name="gpu"	GPU control (GPU frequency)	N/A	N/A	N/A	N/A
name="boost"	SOCPERF thermal level control	event	- 1: event sending enabled -0: event sending disabled	int	0 or 1
name="isolate"	CPU frequency increase control	event	- 1: event sending enabled -0: event sending disabled	int	0 or 1
name="lcd"	LCD control (screen brightness)	N/A	N/A	N/A	N/A
name="volume"	Sound control (volume)	uid	User ID	int	Product-specific
name="current_xxx"	Charging current control (charging current during fast charging and slow charging)	protocol param	Set protocol to current and param to a supported charging protocol, that is, fast charging (sc) or slow charging (buck).	string	protocol="current" param="sc"
name="current_xxx"	Charging current control	event	- 1: event sending enabled -0: event sending disabled	int	0 or 1
name="voltage_xxx"	Charging voltage control (charging voltage during fast charging and slow charging)	protocol param	Set protocol to voltage and param to a charging protocol, that is, fast charging (sc) or slow charging (buck).	string	protocol="voltage" param="buck"
name="voltage_xxx"	Charging voltage control	event	- 1: event sending enabled -0: event sending disabled	int	0 or 1
name="process_ctrl"	Process control (survival status of foreground and background processes)	param	Set param to any string.	string	N/A
name="process_ctrl"	Process control (survival status of foreground and background processes)	event	- 1: event sending enabled -0: event sending disabled If this parameter is not set, the value is defaulted to 0.	int	0 or 1
name="shut_down"	Shutdown control (device shutdown)	event	- 1: event sending enabled -0: event sending disabled	int	0 or 1
name="thermallevel"	Thermal level control (thermal level reporting)	event	- 1: event sending enabled -0: event sending disabled	int	0 or 1
name="popup"	Pop-up window control (pop-up window display)	N/A	N/A	N/A	N/A
name="xxx"	Node thermal control action	protocol param	Set protocol to node. Set param to the node path and rollback value, which are separated by a	backslash ().	string

<action>
    <item name="airplane"/>
    <item name="cpu_big"/>
    <item name="cpu_med"/>
    <item name="cpu_lit"/>
    <item name="gpu"/>
    <item name="boost" event="1"/>
    <item name="isolate" event="1"/>
    <item name="lcd"/>
    <item name="volume" uid="2001,2002"/>
    <item name="current_sc" protocol="current" param="sc" event="1"/>
    <item name="voltage_buck" protocol="voltage" param="buck" event="1"/>
    <item name="process_ctrl" param="32,64,128,256" event=""/>
    <item name="shut_down" event="0"/>
    <item name="thermallevel" event="1"/>
    <item name="popup"/>
    <item name="(action_name)" protocol="node" param="/sys/class/thermal/xxx"/>
    <item name="test"/>
</action>

Write the BUILD.gn file by referring to the BUILD.gn file in the default thermal control configuration folder to pack the thermal_service_config.xml file to the /vendor/etc/thermal_config directory. The configuration is as follows:

import("//build/ohos.gni")                      # Reference build/ohos.gni.

ohos_prebuilt_etc("thermal_service_config") {
    source = "thermal_service_config.xml"
    relative_install_dir = "thermal_config"
    install_images = [ chipset_base_dir ]       # Required configuration for installing the thermal_service_config.xml file in the vendor directory.
    part_name = "product_rk3568"                # Set part_name to product_rk3568 for subsequent build. You can change it as required.
}

Add the build target to module_list in ohos.build. For example:

{
    "parts": {
        "product_rk3568": {
            "module_list": [
                "//vendor/hihope/rk3568/default_app_config:default_app_config",
                "//vendor/hihope/rk3568/image_conf:custom_image_conf",
                "//vendor/hihope/rk3568/preinstall-config:preinstall-config",
                "//vendor/hihope/rk3568/resourceschedule:resourceschedule",
                "//vendor/hihope/rk3568/etc:product_etc_conf",
                "//vendor/hihope/rk3568/thermal/profile:thermal_service_config", // Add the configuration for building of thermal_service_config.
            ]
        }
    },
    "subsystem": "product_hihope"
}

In the preceding code, //vendor/hihope/rk3568/thermal/ is the folder path, profile is the folder name, and thermal_service_config is the build target.

Build the customized version by referring to Quick Start.
```
./build.sh --product-name rk3568 --ccache
```
Burn the customized version to the DAYU200 development board.

Debugging and Verification

Temperature simulation debugging is supported since OpenHarmony 5.0.0 Release. The following procedure implements temperature level transition through simulating temperature changes to verify the custom thermal control policy. Write the custom thermal_service_config.xml file by referring to the thermal_service_config.xml file in the default thermal control configuration folder.

After startup, run the following command to launch the shell command line:
```
hdc shell
```

Obtain the current thermal control information.

hidumper -s 3303 -a -a

The following is the reference thermal control result after customization:

-------------------------------[ability]-------------------------------


----------------------------------ThermalService---------------------------------
name: airplane	strict: 0	enableEvent: 0
name: cpu_big	strict: 0	enableEvent: 0
name: cpu_med	strict: 0	enableEvent: 0
name: cpu_lit	strict: 0	enableEvent: 0
name: gpu	strict: 0	enableEvent: 0
name: boost	strict: 0	enableEvent: 1
name: isolate	strict: 0	enableEvent: 1
name: lcd	strict: 0	enableEvent: 0
name: volume	uid: 2001,2002	strict: 0	enableEvent: 0
name: current_sc    params: sc	protocol: current	strict: 0	enableEvent: 1
name: current_buck    params: buck	protocol: current	strict: 0	enableEvent: 1
name: voltage_sc   params: sc	protocol: voltage	strict: 0	enableEvent: 1
name: voltage_buck   params: buck	protocol: voltage	strict: 0	enableEvent: 1
name: process_ctrl  params: 32,64,128,256	strict: 0	enableEvent: 0
name: shut_down	strict: 0	enableEvent: 0
name: thermallevel	strict: 0	enableEvent: 1
name: popup	strict: 0	enableEvent: 0
name: test	strict: 0	enableEvent: 0

Stop automatic temperature reporting.

Run hidumper -s 3303 -a '-st [f] [...]' to specify whether to enable automatic temperature reporting. Where, ... indicates any character. If f is 0, automatic temperature reporting is disabled. Otherwise, automatic temperature reporting is enabled.
```
$ hidumper -s 3303 -a '-st 0'

-------------------------------[ability]-------------------------------


----------------------------------ThermalService----------------------------------
Temperature reporting has been stopped.
```

Simulate temperature changes.

To trigger the thermal control policy, simulate a low temperature and then a high temperature. Run hidumper -s 3303 -a '-te [name] [num]' to report the simulated temperatures. In the command, name indicates the name of the temperature sensor, and num indicates its temperature. If there are multiple groups of name and num, multiple simulated temperatures are uploaded at the same time.

$ hidumper -s 3303 -a '-te battery 32000 charger 32000'

-------------------------------[ability]-------------------------------


----------------------------------ThermalService----------------------------------
Report temperature [ battery ]: 32000
Report temperature [ charger ]: 32000
$ hidumper -s 3303 -a '-te battery 39000 charger 39000'

-------------------------------[ability]-------------------------------


----------------------------------ThermalService----------------------------------
Report temperature [ battery ]: 39000
Report temperature [ charger ]: 39000

Obtain the current temperature level.

hidumper -s 3303 -a -l

The following shows the temperature level after the simulated temperatures are uploaded:

-------------------------------[ability]-------------------------------


----------------------------------ThermalService----------------------------------
name: base_safe level: 1
name: cold_safe level: 0
name: high_safe level: 0
name: screenoff_charge  level: 0
name: warm_5G   level: 0
name: warm_safe level: 0

View the thermal control node information.
```
cat /data/service/el0/thermal/config/process_ctrl
```
If the thermal control node information is as follows, the process_ctrl thermal control policy is effective:
```
3
```

Reference

During development, you can refer to the default thermal control configuration.

Packing path: /vendor/etc/thermal_config/hdf