M2KAnalogOut: Add support for auto_rearm attribute

- Introduce the auto_rearm attribute to the AnalogOut class.
- This attribute controls the behavior of the DAC when configured to start on a trigger event.
- When auto_rearm is disabled, all previously loaded buffers will be sent to the DAC output upon the trigger event.
- When auto_rearm is enabled, each previously loaded buffer will be sent to the DAC output on each trigger event.

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

include/libm2k/analog/m2kanalogout.hpp

@@ -495,6 +495,32 @@ class LIBM2K_API M2kAnalogOut
 	* @return A pointer to the hardware trigger
 	*/
 	virtual libm2k::M2kHardwareTrigger* getTrigger() = 0;
+
+
+	/**
+	* @brief Allows sequential output of multiple buffers with each trigger event.
+	* @param  enable A boolean value that enables or disables the buffer rearm functionality.
+	*
+	* @note  When disabled, all buffers will be sent at once. Opt to concatenate multiple small buffers into a single buffer to avoid timing problems.
+	* @note  When enabled, each previously pushed buffer will be sent sequentially with each trigger event.
+	* @note  For non-cyclic mode each buffer is sent only once.
+	* @note In cyclic mode:
+	*		- If rearm is disabled, the buffer will be sent continuously.
+	*		- If rearm is enabled, the buffer will be sent once for every trigger event.
+	* @note  Due to hardware limitation, in non-cyclic mode, the channel will idle with the first sample of the next buffer.
+	* @note Only available from firmware v0.33.
+	*/
+	virtual void setBufferRearmOnTrigger(bool enable) = 0;
+
+
+	/**
+	* @brief Retrieve the value of the attribute that controls buffer rearm on trigger
+	* @note The buffer rearm on trigger is disabled by default.
+	* @note The attribute is shared between both channels.
+	* @note Only available from firmware v0.33.
+	* @return A boolean value corresponding to the state of the rearm on trigger.
+	*/
+	virtual bool getBufferRearmOnTrigger() = 0;
 };
 }
 }

src/analog/m2kanalogout_impl.cpp

@@ -75,6 +75,9 @@ M2kAnalogOutImpl::M2kAnalogOutImpl(iio_context *ctx, std::vector<std::string> da
 	// data_available attribute exists only in firmware versions newer than 0.23
 	m_dma_data_available = getDacDevice(0)->hasBufferAttribute("data_available");
 
+	// auto_rearm_trigger attribute is only available in firmware versions newer than 0.33
+	m_auto_rearm_trigger_available = getDacDevice(0)->hasGlobalAttribute("auto_rearm_trigger");
+
 	m_raw_enable_available.push_back(getDacDevice(0)->getChannel(0, true)->hasAttribute("raw_enable"));
 	m_raw_enable_available.push_back(getDacDevice(1)->getChannel(0, true)->hasAttribute("raw_enable"));
 	m_raw_available.push_back(getDacDevice(0)->getChannel(0, true)->hasAttribute("raw"));
@@ -743,4 +746,20 @@ double M2kAnalogOutImpl::getMaximumSamplerate(unsigned int chn_idx)
 libm2k::M2kHardwareTrigger *M2kAnalogOutImpl::getTrigger()
 {
 	return m_trigger;
-}
+}
+
+void M2kAnalogOutImpl::setBufferRearmOnTrigger(bool enable)
+{
+	if (!m_auto_rearm_trigger_available) {
+		THROW_M2K_EXCEPTION("Invalid firmware version: 0.33 or greater is required.", libm2k::EXC_INVALID_FIRMWARE_VERSION);
+	}
+	m_dac_devices[0]->setBoolValue(enable, "auto_rearm_trigger");
+}
+
+bool M2kAnalogOutImpl::getBufferRearmOnTrigger()
+{
+	if (!m_auto_rearm_trigger_available) {
+		THROW_M2K_EXCEPTION("Invalid firmware version: 0.33 or greater is required.", libm2k::EXC_INVALID_FIRMWARE_VERSION);
+	}
+	return m_dac_devices[0]->getBoolValue("auto_rearm_trigger");
+}

src/analog/m2kanalogout_impl.hpp

@@ -96,6 +96,8 @@ class M2kAnalogOutImpl : public M2kAnalogOut
 	unsigned short setVoltageRaw(unsigned int chn_idx, unsigned short raw) override;
 
 	libm2k::M2kHardwareTrigger* getTrigger() override;
+	void setBufferRearmOnTrigger(bool enable) override;
+	bool getBufferRearmOnTrigger() override;	
 
 private:
 	std::shared_ptr<libm2k::utils::DeviceGeneric> m_m2k_fabric;
@@ -110,6 +112,7 @@ class M2kAnalogOutImpl : public M2kAnalogOut
 
 	bool m_dma_start_sync_available;
 	bool m_dma_data_available;
+	bool m_auto_rearm_trigger_available;
 	std::vector<unsigned int> m_nb_kernel_buffers;
 	std::vector<bool> m_raw_enable_available;
 	std::vector<bool> m_raw_available;