Wiznetif: report module power state.

[XuGuohui]

Problem

The device may timeout waiting the ethernet interface to be off() when sleep is requested and the ethernet interface is present.

Solution

Report the Wiznetif power state to system network manager.

Note that the W5500 module is actually on still even if we've called the corresponding API to turn it off. Because there is no hardware pins to control the power to the W5500 module, nor we implement the low power mode for W5500.

Example App

#include "application.h"

STARTUP(System.enableFeature(FEATURE_ETHERNET_DETECTION));

SerialLogHandler l(LOG_LEVEL_ALL);

SYSTEM_MODE(MANUAL);

void setup() {
    while (!Serial.isConnected());
    Log.info("Application started.");

    System.sleep(SystemSleepConfiguration().mode(SystemSleepMode::ULTRA_LOW_POWER).duration(5s));
}

void loop() {
}

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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)

[avtolstoy]

Let's add an argument here and task it with updating internal pwrState_ as well. There shouldn't be any reason to do that externally and then still call into this method.

[avtolstoy]

This could probably be:

if (pwrState_ == state) {
    return;
}
pwrState_ = state;
// Notify

So that you don't have to check externally.

[XuGuohui]

That might miss a power state change event. Image that the pwrState_ is changed to UP on initialization, then powerUp() won't notify the power state.

[avtolstoy]

Okay, let's leave it as-is then 👍

[XuGuohui]

That's not a good example. If the pwrState_ is changed to IF_POWER_STATE_UP somewhere but without notifying the state, somewhere else call notifyPowerState(IF_POWER_STATE_UP) won't notify the power state. Just in case.

[XuGuohui]

While this remind me that we should always notify the power state if possible, especially in powerDown() that may block the waitInterfaceOff(). I'll revise it a little bit.