Initial work on DAC for Teensy-LC (still incomplete)

output_dac.cpp

@@ -152,9 +152,113 @@ void AudioOutputAnalog::isr(void)
 	if (AudioOutputAnalog::update_responsibility) AudioStream::update_all();
 }
 
-#else
 
 
+#elif defined (__MKL26Z64__)
+
+DMAMEM static uint16_t dac_buffer1[AUDIO_BLOCK_SAMPLES];
+DMAMEM static uint16_t dac_buffer2[AUDIO_BLOCK_SAMPLES];
+audio_block_t * AudioOutputAnalog::block_left_1st = NULL;
+bool AudioOutputAnalog::update_responsibility = false;
+DMAChannel AudioOutputAnalog::dma1(false);
+DMAChannel AudioOutputAnalog::dma2(false);
+
+void AudioOutputAnalog::begin(void)
+{
+	dma1.begin(true); // Allocate the DMA channels first
+	dma2.begin(true); // Allocate the DMA channels first
+
+	delay(2500);
+	Serial.println("AudioOutputAnalog begin");
+	delay(10);
+
+	SIM_SCGC6 |= SIM_SCGC6_DAC0;
+	DAC0_C0 = DAC_C0_DACEN | DAC_C0_DACRFS;		// VDDA (3.3V) ref
+	// slowly ramp up to DC voltage, approx 1/4 second
+	for (int16_t i=0; i<2048; i+=8) {
+		*(int16_t *)&(DAC0_DAT0L) = i;
+		delay(1);
+	}
+
+	// commandeer FTM1 for timing (PWM on pin 3 & 4 will become 22 kHz)
+	FTM1_SC = 0;
+	FTM1_CNT = 0;
+	FTM1_MOD = (uint32_t)((F_PLL/2) / AUDIO_SAMPLE_RATE_EXACT + 0.5);
+	FTM1_SC = FTM_SC_CLKS(1);
+
+	dma1.sourceBuffer(dac_buffer1, sizeof(dac_buffer1));
+	dma1.destination(*(int16_t *)&DAC0_DAT0L);
+	dma1.interruptAtCompletion();
+	dma1.disableOnCompletion();
+	dma1.triggerAtCompletionOf(dma2);
+	dma1.triggerAtHardwareEvent(DMAMUX_SOURCE_FTM1_OV);
+	dma1.attachInterrupt(isr1);
+
+	dma2.sourceBuffer(dac_buffer2, sizeof(dac_buffer2));
+	dma2.destination(*(int16_t *)&DAC0_DAT0L);
+	dma2.interruptAtCompletion();
+	dma2.disableOnCompletion();
+	dma2.triggerAtCompletionOf(dma1);
+	dma2.triggerAtHardwareEvent(DMAMUX_SOURCE_FTM1_OV);
+	dma2.attachInterrupt(isr2);
+
+	update_responsibility = update_setup();
+/*
+	dma.TCD->SADDR = dac_buffer;
+	dma.TCD->SOFF = 2;
+	dma.TCD->ATTR = DMA_TCD_ATTR_SSIZE(1) | DMA_TCD_ATTR_DSIZE(1);
+	dma.TCD->NBYTES_MLNO = 2;
+	dma.TCD->SLAST = -sizeof(dac_buffer);
+	dma.TCD->DADDR = &DAC0_DAT0L;
+	dma.TCD->DOFF = 0;
+	dma.TCD->CITER_ELINKNO = sizeof(dac_buffer) / 2;
+	dma.TCD->DLASTSGA = 0;
+	dma.TCD->BITER_ELINKNO = sizeof(dac_buffer) / 2;
+	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 AudioOutputAnalog::isr1(void)
+{
+	dma1.clearInterrupt();
+
+}
+
+void AudioOutputAnalog::isr2(void)
+{
+	dma2.clearInterrupt();
+
+
+}
+
+
+void AudioOutputAnalog::update(void)
+{
+	audio_block_t *block;
+	block = receiveReadOnly();
+	if (block) {
+		__disable_irq();
+		if (block_left_1st == NULL) {
+			block_left_1st = block;
+			__enable_irq();
+		} else {
+			audio_block_t *tmp = block_left_1st;
+			block_left_1st = block;
+			__enable_irq();
+			release(tmp);
+		}
+	}
+}
+
+
+
+
+#else
+
 void AudioOutputAnalog::begin(void)
 {
 }

output_dac.h

@@ -42,8 +42,15 @@ private:
 	static audio_block_t *block_left_2nd;
 	static bool update_responsibility;
 	audio_block_t *inputQueueArray[1];
+#if defined(KINETISK)
 	static DMAChannel dma;
 	static void isr(void);
+#elif defined(KINETISL)
+	static DMAChannel dma1;
+	static DMAChannel dma2;
+	static void isr1(void);
+	static void isr2(void);
+#endif
 };
 
 #endif