73 lines
2.1 KiB
C
73 lines
2.1 KiB
C
/**
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* Copyright 2022 Colin Lam, Ploopy Corporation
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* SPECIAL THANKS TO:
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* @miketeachman (github.com/miketeachman)
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* @jimmo (github.com/jimmo)
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* @dlech (github.com/dlech)
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* for their exceptional work on the I2S library for the rp2 port of the
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* Micropython project (github.com/micropython/micropython).
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*/
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#ifndef I2S_H
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#define I2S_H
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#include "pico/stdlib.h"
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#include "hardware/pio.h"
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#include "ringbuf.h"
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#define SAMPLES_PER_FRAME 2
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#define PIO_INSTRUCTIONS_PER_BIT 2
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#define RINGBUF_LEN_IN_BYTES 16384
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#define I2S_NUM_DMA_CHANNELS 2
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#define SIZEOF_DMA_BUFFER_IN_BYTES 768
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#define SIZEOF_HALF_DMA_BUFFER_IN_BYTES (SIZEOF_DMA_BUFFER_IN_BYTES / 2)
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typedef enum {
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GP_INPUT = 0,
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GP_OUTPUT = 1
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} gpio_dir_t;
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typedef struct _i2s_obj_t {
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uint sck_pin;
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uint ws_pin;
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uint sd_pin;
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PIO pio;
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uint8_t sm;
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float sampling_rate;
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const pio_program_t *pio_program;
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uint prog_offset;
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int dma_channel[I2S_NUM_DMA_CHANNELS];
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uint8_t dma_buffer[SIZEOF_DMA_BUFFER_IN_BYTES];
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ring_buf_t ring_buffer;
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} i2s_obj_t;
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extern i2s_obj_t i2s_write_obj;
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void i2s_write_init(i2s_obj_t *);
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uint i2s_stream_write(i2s_obj_t *, const uint8_t *, uint);
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void dma_irq_handler(uint8_t);
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void dma_irq_write_handler(void);
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void gpio_init_i2s(PIO, uint8_t, uint, uint8_t, gpio_dir_t);
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void dma_configure(i2s_obj_t *);
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uint8_t *dma_get_buffer(i2s_obj_t *, uint);
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void feed_dma(i2s_obj_t *, uint8_t *);
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uint32_t copy_userbuf_to_ringbuf(i2s_obj_t *, const uint8_t *, uint);
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#endif |