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- /* 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.
- */
-
- #include "input_i2s.h"
- #include "output_i2s.h"
-
- DMAMEM static uint32_t i2s_rx_buffer[AUDIO_BLOCK_SAMPLES];
- audio_block_t * AudioInputI2S::block_left = NULL;
- audio_block_t * AudioInputI2S::block_right = NULL;
- uint16_t AudioInputI2S::block_offset = 0;
- bool AudioInputI2S::update_responsibility = false;
- DMAChannel AudioInputI2S::dma(false);
-
-
- void AudioInputI2S::begin(void)
- {
- dma.begin(true); // Allocate the DMA channel first
-
- //block_left_1st = NULL;
- //block_right_1st = NULL;
-
- // TODO: should we set & clear the I2S_RCSR_SR bit here?
- AudioOutputI2S::config_i2s();
-
- CORE_PIN13_CONFIG = PORT_PCR_MUX(4); // pin 13, PTC5, I2S0_RXD0
-
- dma.TCD->SADDR = &I2S0_RDR0;
- dma.TCD->SOFF = 0;
- dma.TCD->ATTR = DMA_TCD_ATTR_SSIZE(1) | DMA_TCD_ATTR_DSIZE(1);
- dma.TCD->NBYTES_MLNO = 2;
- dma.TCD->SLAST = 0;
- dma.TCD->DADDR = i2s_rx_buffer;
- dma.TCD->DOFF = 2;
- dma.TCD->CITER_ELINKNO = sizeof(i2s_rx_buffer) / 2;
- dma.TCD->DLASTSGA = -sizeof(i2s_rx_buffer);
- dma.TCD->BITER_ELINKNO = sizeof(i2s_rx_buffer) / 2;
- dma.TCD->CSR = DMA_TCD_CSR_INTHALF | DMA_TCD_CSR_INTMAJOR;
-
- dma.triggerAtHardwareEvent(DMAMUX_SOURCE_I2S0_RX);
- update_responsibility = update_setup();
- dma.enable();
-
- I2S0_RCSR |= I2S_RCSR_RE | I2S_RCSR_BCE | I2S_RCSR_FRDE | I2S_RCSR_FR;
- I2S0_TCSR |= I2S_TCSR_TE | I2S_TCSR_BCE; // TX clock enable, because sync'd to TX
- dma.attachInterrupt(isr);
- }
-
- void AudioInputI2S::isr(void)
- {
- uint32_t daddr, offset;
- const int16_t *src, *end;
- int16_t *dest_left, *dest_right;
- audio_block_t *left, *right;
-
- //digitalWriteFast(3, HIGH);
- daddr = (uint32_t)(dma.TCD->DADDR);
- dma.clearInterrupt();
-
- if (daddr < (uint32_t)i2s_rx_buffer + sizeof(i2s_rx_buffer) / 2) {
- // DMA is receiving to the first half of the buffer
- // need to remove data from the second half
- src = (int16_t *)&i2s_rx_buffer[AUDIO_BLOCK_SAMPLES/2];
- end = (int16_t *)&i2s_rx_buffer[AUDIO_BLOCK_SAMPLES];
- if (AudioInputI2S::update_responsibility) AudioStream::update_all();
- } else {
- // DMA is receiving to the second half of the buffer
- // need to remove data from the first half
- src = (int16_t *)&i2s_rx_buffer[0];
- end = (int16_t *)&i2s_rx_buffer[AUDIO_BLOCK_SAMPLES/2];
- }
- left = AudioInputI2S::block_left;
- right = AudioInputI2S::block_right;
- if (left != NULL && right != NULL) {
- offset = AudioInputI2S::block_offset;
- if (offset <= AUDIO_BLOCK_SAMPLES/2) {
- dest_left = &(left->data[offset]);
- dest_right = &(right->data[offset]);
- AudioInputI2S::block_offset = offset + AUDIO_BLOCK_SAMPLES/2;
- do {
- //n = *src++;
- //*dest_left++ = (int16_t)n;
- //*dest_right++ = (int16_t)(n >> 16);
- *dest_left++ = *src++;
- *dest_right++ = *src++;
- } while (src < end);
- }
- }
- //digitalWriteFast(3, LOW);
- }
-
-
-
- void AudioInputI2S::update(void)
- {
- audio_block_t *new_left=NULL, *new_right=NULL, *out_left=NULL, *out_right=NULL;
-
- // allocate 2 new blocks, but if one fails, allocate neither
- new_left = allocate();
- if (new_left != NULL) {
- new_right = allocate();
- if (new_right == NULL) {
- release(new_left);
- new_left = NULL;
- }
- }
- __disable_irq();
- if (block_offset >= AUDIO_BLOCK_SAMPLES) {
- // the DMA filled 2 blocks, so grab them and get the
- // 2 new blocks to the DMA, as quickly as possible
- out_left = block_left;
- block_left = new_left;
- out_right = block_right;
- block_right = new_right;
- block_offset = 0;
- __enable_irq();
- // then transmit the DMA's former blocks
- transmit(out_left, 0);
- release(out_left);
- transmit(out_right, 1);
- release(out_right);
- //Serial.print(".");
- } else if (new_left != NULL) {
- // the DMA didn't fill blocks, but we allocated blocks
- if (block_left == NULL) {
- // the DMA doesn't have any blocks to fill, so
- // give it the ones we just allocated
- block_left = new_left;
- block_right = new_right;
- block_offset = 0;
- __enable_irq();
- } else {
- // the DMA already has blocks, doesn't need these
- __enable_irq();
- release(new_left);
- release(new_right);
- }
- } else {
- // The DMA didn't fill blocks, and we could not allocate
- // memory... the system is likely starving for memory!
- // Sadly, there's nothing we can do.
- __enable_irq();
- }
- }
-
-
- /******************************************************************/
-
-
- void AudioInputI2Sslave::begin(void)
- {
- dma.begin(true); // Allocate the DMA channel first
-
- //block_left_1st = NULL;
- //block_right_1st = NULL;
-
- AudioOutputI2Sslave::config_i2s();
-
- CORE_PIN13_CONFIG = PORT_PCR_MUX(4); // pin 13, PTC5, I2S0_RXD0
-
- dma.TCD->SADDR = &I2S0_RDR0;
- dma.TCD->SOFF = 0;
- dma.TCD->ATTR = DMA_TCD_ATTR_SSIZE(1) | DMA_TCD_ATTR_DSIZE(1);
- dma.TCD->NBYTES_MLNO = 2;
- dma.TCD->SLAST = 0;
- dma.TCD->DADDR = i2s_rx_buffer;
- dma.TCD->DOFF = 2;
- dma.TCD->CITER_ELINKNO = sizeof(i2s_rx_buffer) / 2;
- dma.TCD->DLASTSGA = -sizeof(i2s_rx_buffer);
- dma.TCD->BITER_ELINKNO = sizeof(i2s_rx_buffer) / 2;
- dma.TCD->CSR = DMA_TCD_CSR_INTHALF | DMA_TCD_CSR_INTMAJOR;
-
- dma.triggerAtHardwareEvent(DMAMUX_SOURCE_I2S0_RX);
- update_responsibility = update_setup();
- dma.enable();
-
- I2S0_RCSR |= I2S_RCSR_RE | I2S_RCSR_BCE | I2S_RCSR_FRDE | I2S_RCSR_FR;
- I2S0_TCSR |= I2S_TCSR_TE | I2S_TCSR_BCE; // TX clock enable, because sync'd to TX
- dma.attachInterrupt(isr);
- }
-
-
-
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