M2kAnalogIn: sync calibration state with device attrs and use new cal…

…ibration attr

- Sync class parameters: m_adc_calib_offset, m_adc_calib_gain with device attributes.
These are used to calibrate the raw data to volts.
- In firmware version 0.32, the device attribute won't be used by the hardware,
samples will be recieved uncalibrated. The calibration will be done in software.

- I new libm2k, use the calibration attr is used to disable setting the computed calibration values in HW.
- Note:
    - set calibration = 'true' (string vale): stops the HW calibration
    - set calibration = 'false' (string value): enables the HW calibration

Signed-off-by: Adrian Stanea <[email protected]>

src/analog/m2kanalogin_impl.cpp

@@ -43,10 +43,16 @@ M2kAnalogInImpl::M2kAnalogInImpl(iio_context * ctx, std::string adc_dev, bool sy
 	m_trigger(trigger)
 {
 	LIBM2K_LOG(INFO, "[BEGIN] Initialize M2kAnalogIn");
+	firmware_version = Utils::getFirmwareVersion(ctx);
+
 	m_m2k_adc = make_shared<DeviceIn>(ctx, adc_dev);
 	m_m2k_fabric = make_shared<DeviceGeneric>(ctx, "m2k-fabric");
 	m_ad5625_dev = make_shared<DeviceGeneric>(ctx, "ad5625");
 
+	if (firmware_version >= "v0.32") {
+		setCalibrateHDL("true"); 
+	}
+
 	/* Filters applied while decimating affect the
 		/ amplitude of the received  data */
 	m_filter_compensation_table[1E8] = 1.00;
@@ -135,6 +141,9 @@ void M2kAnalogInImpl::syncDevice()
 		} else {
                         m_adc_calib_offset.at(i) = 2048;
 		}
+		if (firmware_version >= "v0.32") {
+			m_adc_calib_gain.at(i) = getCalibscale(i);
+		}
 		m_adc_hw_offset_raw.at(i) = m_ad5625_dev->getLongValue(2 + i, "raw", true);
 		m_adc_hw_vert_offset.at(i) = convertRawToVoltsVerticalOffset(static_cast<ANALOG_IN_CHANNEL>(i), m_adc_hw_offset_raw.at(i) - m_adc_calib_offset.at(i));
 
@@ -241,6 +250,10 @@ double M2kAnalogInImpl::setCalibscale(unsigned int index, double calibscale)
 	if (index >= getNbChannels()) {
 		THROW_M2K_EXCEPTION("M2kAnalogIn: no such channel", libm2k::EXC_OUT_OF_RANGE);
 	}
+	// update class attribute as well as the attribute in the device
+	if (firmware_version >= "v0.32") {
+		m_adc_calib_gain.at(index) = calibscale;
+	}
 	return m_m2k_adc->setDoubleValue(index, calibscale, "calibscale");
 }
 
@@ -941,3 +954,12 @@ int M2kAnalogInImpl::getAdcCalibOffset(ANALOG_IN_CHANNEL channel)
 		return (adc_hw_offset - convertVoltsToRawVerticalOffset(channel, m_adc_hw_vert_offset.at(channel)));
 	}
 }
+
+void M2kAnalogInImpl::setCalibrateHDL(std::string calibrate_val)
+{
+	m_m2k_adc->setStringValue("calibrate", calibrate_val);
+}
+std::string M2kAnalogInImpl::getCalibrateHDL()
+{
+	return m_m2k_adc->getStringValue("calibrate");
+}

src/analog/m2kanalogin_impl.hpp

@@ -141,6 +141,7 @@ class M2kAnalogInImpl : public M2kAnalogIn
 	bool hasCalibbias();
 	void loadNbKernelBuffers();
 private:
+	std::string firmware_version;
 	std::shared_ptr<libm2k::utils::DeviceGeneric> m_ad5625_dev;
 	std::shared_ptr<libm2k::utils::DeviceGeneric> m_m2k_fabric;
 	std::shared_ptr<libm2k::utils::DeviceIn> m_m2k_adc;
@@ -180,6 +181,21 @@ class M2kAnalogInImpl : public M2kAnalogIn
 
 	int convertVoltsToRawVerticalOffset(ANALOG_IN_CHANNEL channel, double vertOffset);
 	double convertRawToVoltsVerticalOffset(ANALOG_IN_CHANNEL channel, int rawVertOffset);
+
+	/**
+	 * This function can stop the calibration process for the ADC at the HW level.
+	 * The possible values can be checked in IIO in the "calibrate_available" device attribute of m2k-adc.
+	 * 
+	 * When calibrate is set to true, the calibration won't affect the ADC samples. When set to false 
+	 * the calibration is applied. It should be set before doing calibration to avoid sending samples.
+	 * 
+	 * Introduced in fw v0.32 to solve a bug where after HW calibration, some samples were missing due to rounding errors.
+	 * 
+	 * @param calibrate_val The calibration value to set. Can take values "true" or "false" as std::strings.
+	 *                      
+	 */
+	void setCalibrateHDL(std::string calibrate_val);
+	std::string getCalibrateHDL();
 };
 }
 }