Allow power manager to disable charging

[eberseth]

Problem

The power manager may override user requests to disable battery charging. While the user may set the charge state on the PMIC, the power manager may enable charge state silently.

Solution

Add a flag for non-volatile power management configuration that ensures that the power manager honor user requests to disable charging. Additionally create get methods for the configuration so that the user can query the current configuration.

Steps to Test

Which unit/integration/application tests are applicable to this code change? (At minimum a test of some kind should be provided)

Example App

SerialLogHandler logHandler;

void setup() {
    // Apply a custom power configuration
    SystemPowerConfiguration conf;

    conf.feature(SystemPowerFeature::DISABLE_CHARGING);

    int res = System.setPowerConfiguration(conf);
    Log.info("setPowerConfiguration=%d", res);
    // returns SYSTEM_ERROR_NONE (0) in case of success

    // Settings are persisted, you normally wouldn't do this on every startup.
}

void loop() {
    auto config = System.getPowerConfiguration();
    Log.info("Current PMIC settings:");
    Log.info("PMIC detection: %s", cfg.isFeatureSet(SystemPowerFeature::PMIC_DETECTION) ? "true" : "false");
    Log.info("Use VIN with USB: %s", cfg.isFeatureSet(SystemPowerFeature::USE_VIN_SETTINGS_WITH_USB_HOST) ? "true" : "false");
    Log.info("Power manager disabled: %s", cfg.isFeatureSet(SystemPowerFeature::DISABLE) ? "true" : "false");
    Log.info("Charging disabled: %s", cfg.isFeatureSet(SystemPowerFeature::DISABLE_CHARGING) ? "true" : "false");
    Log.info("Input voltage: %u mV", cfg.powerSourceMinVoltage())
    Log.info("Input current: %u mA", cfg.powerSourceMaxCurrent());
    Log.info("Charge voltage: %u mV", cfg.batteryChargeVoltage());
    Log.info("Charge current: %u mA", cfg.batteryChargeCurrent());
}

References

N/A

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Completeness

• User is totes amazing for contributing!
• Contributor has signed CLA (Info here)
• Problem and Solution clearly stated
• Run unit/integration/application tests on device
• Added documentation
• Added to CHANGELOG.md after merging (add links to docs and issues)

[monkbroc]

I'll let Guo-Hui and Andrey review. This is beyond my knowledge to meaningfully review.

[avtolstoy]

Mainly due to dynalib change and ABI problem with getConfig().

[avtolstoy]

TODO: (can be a separate PR) let's add three tests 1) disable/enable charging in runtime and verifying configuration and actual PMIC state 2) disable/enable charging, resetting and making sure that the necessary charging state is set on boot 3) disable/enable chargin, triggering PMIC watchdog and making sure that the necessary charging state is achieved after watchdog timer expires.

[eberseth]

Yeah, I'm still testing some of this code so I didn't add the tests here yet.