hyperion.ng/libsrc/leddevice/dev_hid/ProviderHID.cpp

// STL includes
#include <cstring>
#include <iostream>

// Qt includes
#include <QTimer>

// Local Hyperion includes
#include "ProviderHID.h"

ProviderHID::ProviderHID()
	:	_VendorId(0)
	  , _ProductId(0)
	  , _useFeature(false)
	  , _deviceHandle(nullptr)
	  , _delayAfterConnect_ms (0)
	  , _blockedForDelay(false)
{
}

ProviderHID::~ProviderHID()
{
}

bool ProviderHID::init(const QJsonObject &deviceConfig)
{
	bool isInitOK = LedDevice::init(deviceConfig);

	_delayAfterConnect_ms = deviceConfig["delayAfterConnect"].toInt(0);
	auto VendorIdString   = deviceConfig["VID"].toString("0x2341").toStdString();
	auto ProductIdString  = deviceConfig["PID"].toString("0x8036").toStdString();

	// Convert HEX values to integer
	_VendorId = std::stoul(VendorIdString, nullptr, 16);
	_ProductId = std::stoul(ProductIdString, nullptr, 16);

	return isInitOK;
}

int ProviderHID::open()
{
	int retval = -1;
	QString errortext;
	_deviceReady = false;

	if ( init(_devConfig) )
	{
		// Initialize the usb context
		int error = hid_init();
		if (error != 0)
		{
			//Error(_log, "Error while initializing the hidapi context");
			errortext = "Error while initializing the hidapi context";
		}
		else
		{
			Debug(_log,"Hidapi initialized");

			// Open the device
			Info(_log, "Opening device: VID %04hx PID %04hx\n", _VendorId, _ProductId);
			_deviceHandle = hid_open(_VendorId, _ProductId, nullptr);

			if (_deviceHandle == nullptr)
			{
				// Failed to open the device
				Error(_log,"Failed to open HID device. Maybe your PID/VID setting is wrong? Make sure to add a udev rule/use sudo.");
				errortext = "Failed to open HID device";

				// http://www.signal11.us/oss/hidapi/
				/*
				std::cout << "Showing a list of all available HID devices:" << std::endl;
				auto devs = hid_enumerate(0x00, 0x00);
				auto cur_dev = devs;
				while (cur_dev) {
					printf("Device Found\n  type: %04hx %04hx\n  path: %s\n  serial_number: %ls",
						cur_dev->vendor_id, cur_dev->product_id, cur_dev->path, cur_dev->serial_number);
					printf("\n");
					printf("  Manufacturer: %ls\n", cur_dev->manufacturer_string);
					printf("  Product:      %ls\n", cur_dev->product_string);
					printf("\n");
					cur_dev = cur_dev->next;
				}
				hid_free_enumeration(devs);
				*/
			}
			else
			{
				Info(_log,"Opened HID device successful");
				// Everything is OK -> enable device
				_deviceReady = true;
				setEnable(true);
				retval = 0;
			}

			// Wait after device got opened if enabled
			if (_delayAfterConnect_ms > 0)
			{
				_blockedForDelay = true;
				QTimer::singleShot(_delayAfterConnect_ms, this, SLOT(unblockAfterDelay()));
				Debug(_log, "Device blocked for %d  ms", _delayAfterConnect_ms);
			}
		}
		// On error/exceptions, set LedDevice in error
		if ( retval < 0 )
		{
			this->setInError( errortext );
		}
	}
	return retval;
}

void ProviderHID::close()
{
	LedDevice::close();

	// LedDevice specific closing activites
	if (_deviceHandle != nullptr)
	{
		hid_close(_deviceHandle);
		_deviceHandle = nullptr;
	}

	hid_exit();
}

int ProviderHID::writeBytes(const unsigned size, const uint8_t * data)
{
	if (_blockedForDelay) {
		return 0;
	}

	if (_deviceHandle == nullptr)
	{
		// try to reopen
		auto status = open();
		if(status < 0){
			// Try again in 3 seconds
			int delay_ms = 3000;
			_blockedForDelay = true;
			QTimer::singleShot(delay_ms, this, SLOT(unblockAfterDelay()));
			Debug(_log,"Device blocked for %d ms", delay_ms);
		}
		// Return here, to not write led data if the device should be blocked after connect
		return status;
	}

	// Prepend report ID to the buffer
	uint8_t ledData[size + 1];
	ledData[0] = 0; // Report ID
	memcpy(ledData + 1, data, size_t(size));

	// Send data via feature or out report
	int ret;
	if(_useFeature){
		ret = hid_send_feature_report(_deviceHandle, ledData, size + 1);
	}
	else{
		ret = hid_write(_deviceHandle, ledData, size + 1);
	}
	
	// Handle first error
	if(ret < 0){
		Error(_log,"Failed to write to HID device.");

		// Try again
		if(_useFeature){
			ret = hid_send_feature_report(_deviceHandle, ledData, size + 1);
		}
		else{
			ret = hid_write(_deviceHandle, ledData, size + 1);
		}

		// Writing failed again, device might have disconnected
		if(ret < 0){
			Error(_log,"Failed to write to HID device.");
		
			hid_close(_deviceHandle);
			_deviceHandle = nullptr;
		}
	}
	
	return ret;
}

void ProviderHID::unblockAfterDelay()
{
	Debug(_log,"Device unblocked");
	_blockedForDelay = false;
}