Add AudioOutputAnalogStereo

Audio.h

 #include "input_i2s_quad.h"
 #include "mixer.h"
 #include "output_dac.h"
+#include "output_dacs.h"
 #include "output_i2s.h"
 #include "output_i2s_quad.h"
 #include "output_pwm.h"

output_dacs.cpp

+/* Audio Library for Teensy 3.X
+ * Copyright (c) 2016, Paul Stoffregen, paul@pjrc.com
+ *
+ * Development of this audio library was funded by PJRC.COM, LLC by sales of
+ * Teensy and Audio Adaptor boards.  Please support PJRC's efforts to develop
+ * open source software by purchasing Teensy or other PJRC products.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice, development funding notice, and this permission
+ * notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "output_dacs.h"
+#include "utility/pdb.h"
+
+#if defined(__MK64FX512__) || defined(__MK66FX1M0__)
+
+DMAMEM static uint32_t dac_buffer[AUDIO_BLOCK_SAMPLES*2];
+audio_block_t * AudioOutputAnalogStereo::block_left_1st = NULL;
+audio_block_t * AudioOutputAnalogStereo::block_left_2nd = NULL;
+audio_block_t * AudioOutputAnalogStereo::block_right_1st = NULL;
+audio_block_t * AudioOutputAnalogStereo::block_right_2nd = NULL;
+audio_block_t AudioOutputAnalogStereo::block_silent;
+bool AudioOutputAnalogStereo::update_responsibility = false;
+DMAChannel AudioOutputAnalogStereo::dma(false);
+
+void AudioOutputAnalogStereo::begin(void)
+{
+	dma.begin(true); // Allocate the DMA channel first
+
+	SIM_SCGC2 |= SIM_SCGC2_DAC0 | SIM_SCGC2_DAC1;
+	DAC0_C0 = DAC_C0_DACEN;                   // 1.2V VDDA is DACREF_2
+	DAC1_C0 = DAC_C0_DACEN;
+	memset(&block_silent, 0, sizeof(block_silent));
+
+	// slowly ramp up to DC voltage, approx 1/4 second
+	for (int16_t i=0; i<2048; i+=8) {
+		*(int16_t *)&(DAC0_DAT0L) = i;
+		*(int16_t *)&(DAC1_DAT0L) = i;
+		delay(1);
+	}
+
+	// set the programmable delay block to trigger DMA requests
+	if (!(SIM_SCGC6 & SIM_SCGC6_PDB)
+	  || (PDB0_SC & PDB_CONFIG) != PDB_CONFIG
+	  || PDB0_MOD != PDB_PERIOD
+	  || PDB0_IDLY != 1
+	  || PDB0_CH0C1 != 0x0101) {
+		SIM_SCGC6 |= SIM_SCGC6_PDB;
+		PDB0_IDLY = 1;
+		PDB0_MOD = PDB_PERIOD;
+		PDB0_SC = PDB_CONFIG | PDB_SC_LDOK;
+		PDB0_SC = PDB_CONFIG | PDB_SC_SWTRIG;
+		PDB0_CH0C1 = 0x0101;
+	}
+
+	dma.TCD->SADDR = dac_buffer;
+	dma.TCD->SOFF = 2;
+	dma.TCD->ATTR = DMA_TCD_ATTR_SSIZE(DMA_TCD_ATTR_SIZE_16BIT) |
+		DMA_TCD_ATTR_DSIZE(DMA_TCD_ATTR_SIZE_16BIT);
+	dma.TCD->NBYTES_MLNO = DMA_TCD_NBYTES_MLOFFYES_NBYTES(4) | DMA_TCD_NBYTES_DMLOE |
+		DMA_TCD_NBYTES_MLOFFYES_MLOFF((&DAC0_DAT0L - &DAC1_DAT0L) * 2);
+	dma.TCD->SLAST = -sizeof(dac_buffer);
+	dma.TCD->DADDR = &DAC0_DAT0L;
+	dma.TCD->DOFF = &DAC1_DAT0L - &DAC0_DAT0L;
+	dma.TCD->CITER_ELINKNO = sizeof(dac_buffer) / 4;
+	dma.TCD->DLASTSGA = (&DAC0_DAT0L - &DAC1_DAT0L) * 2;
+	dma.TCD->BITER_ELINKNO = sizeof(dac_buffer) / 4;
+	dma.TCD->CSR = DMA_TCD_CSR_INTHALF | DMA_TCD_CSR_INTMAJOR;
+	dma.triggerAtHardwareEvent(DMAMUX_SOURCE_PDB);
+	update_responsibility = update_setup();
+	dma.enable();
+	dma.attachInterrupt(isr);
+}
+
+void AudioOutputAnalogStereo::analogReference(int ref)
+{
+	// TODO: this should ramp gradually to the new DC level
+	if (ref == INTERNAL) {
+		DAC0_C0 &= ~DAC_C0_DACRFS; // 1.2V
+	} else {
+		DAC0_C0 |= DAC_C0_DACRFS;  // 3.3V
+	}
+}
+
+
+void AudioOutputAnalogStereo::update(void)
+{
+	audio_block_t *block_left, *block_right;
+
+	block_left = receiveReadOnly(0);  // input 0
+	block_right = receiveReadOnly(1); // input 1
+	__disable_irq();
+	if (block_left) {
+		if (block_left_1st == NULL) {
+			block_left_1st = block_left;
+			block_left = NULL;
+		} else if (block_left_2nd == NULL) {
+			block_left_2nd = block_left;
+			block_left = NULL;
+		} else {
+			audio_block_t *tmp = block_left_1st;
+			block_left_1st = block_left_2nd;
+			block_left_2nd = block_left;
+			block_left = tmp;
+		}
+	}
+	if (block_right) {
+		if (block_right_1st == NULL) {
+			block_right_1st = block_right;
+			block_right = NULL;
+		} else if (block_right_2nd == NULL) {
+			block_right_2nd = block_right;
+			block_right = NULL;
+		} else {
+			audio_block_t *tmp = block_right_1st;
+			block_right_1st = block_right_2nd;
+			block_right_2nd = block_right;
+			block_right = tmp;
+		}
+	}
+	__enable_irq();
+	if (block_left) release(block_left);
+	if (block_right) release(block_right);
+}
+
+// TODO: the DAC has much higher bandwidth than the datasheet says
+// can we output a 2X oversampled output, for easier filtering?
+
+void AudioOutputAnalogStereo::isr(void)
+{
+	const uint32_t *src_left, *src_right, *end;
+	uint32_t *dest;
+	audio_block_t *block_left, *block_right;
+	uint32_t saddr;
+
+	saddr = (uint32_t)(dma.TCD->SADDR);
+	dma.clearInterrupt();
+	if (saddr < (uint32_t)dac_buffer + sizeof(dac_buffer) / 2) {
+		// DMA is transmitting the first half of the buffer
+		// so we must fill the second half
+		dest = dac_buffer + AUDIO_BLOCK_SAMPLES;
+		end = dac_buffer + AUDIO_BLOCK_SAMPLES*2;
+	} else {
+		// DMA is transmitting the second half of the buffer
+		// so we must fill the first half
+		dest = dac_buffer;
+		end = dac_buffer + AUDIO_BLOCK_SAMPLES;
+	}
+	block_left = block_left_1st;
+	if (!block_left) block_left = &block_silent;
+	block_right = block_right_1st;
+	if (!block_right) block_right = &block_silent;
+
+	src_left = (const uint32_t *)(block_left->data);
+	src_right = (const uint32_t *)(block_right->data);
+	do {
+		// TODO: can this be optimized?
+		uint32_t left = *src_left++;
+		uint32_t right = *src_right++;
+		uint32_t out1 = ((left & 0xFFFF) + 32767) >> 4;
+		out1 |= (((right & 0xFFFF) + 32767) >> 4) << 16;
+		uint32_t out2 = ((left >> 16) + 32767) >> 4;
+		out2 |= (((right >> 16) + 32767) >> 4) << 16;
+		*dest++ = out1;
+		*dest++ = out2;
+	} while (dest < end);
+
+	if (block_left != &block_silent) {
+		release(block_left);
+		block_left_1st = block_left_2nd;
+		block_left_2nd = NULL;
+	}
+	if (block_right != &block_silent) {
+		release(block_right);
+		block_left_1st = block_left_2nd;
+		block_left_2nd = NULL;
+	}
+
+	if (update_responsibility) update_all();
+}
+
+#else // not __MK64FX512__ or __MK66FX1M0__
+
+void AudioOutputAnalogStereo::begin(void)
+{
+}
+
+void AudioOutputAnalogStereo::update(void)
+{
+	audio_block_t *block;
+	block = receiveReadOnly(0); // input 0
+	if (block) release(block);
+	block = receiveReadOnly(1); // input 1
+	if (block) release(block);
+}
+
+#endif
+
+

output_dacs.h

+/* Audio Library for Teensy 3.X
+ * Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
+ *
+ * Development of this audio library was funded by PJRC.COM, LLC by sales of
+ * Teensy and Audio Adaptor boards.  Please support PJRC's efforts to develop
+ * open source software by purchasing Teensy or other PJRC products.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice, development funding notice, and this permission
+ * notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef output_dacs_h_
+#define output_dacs_h_
+
+#include "Arduino.h"
+#include "AudioStream.h"
+#include "DMAChannel.h"
+
+class AudioOutputAnalogStereo : public AudioStream
+{
+public:
+	AudioOutputAnalogStereo(void) : AudioStream(2, inputQueueArray) { begin(); }
+	virtual void update(void);
+	void begin(void);
+	void analogReference(int ref);
+private:
+	static audio_block_t *block_left_1st;
+	static audio_block_t *block_left_2nd;
+	static audio_block_t *block_right_1st;
+	static audio_block_t *block_right_2nd;
+	static audio_block_t block_silent;
+	static bool update_responsibility;
+	audio_block_t *inputQueueArray[2];
+	static DMAChannel dma;
+	static void isr(void);
+};
+
+#endif