55 lines
2.4 KiB
C
55 lines
2.4 KiB
C
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/*
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* This file is part of the Micro Python project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "shared_dma.h"
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// We allocate two DMA resources for the entire lifecycle of the board (not the
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// vm) because the general_dma resource will be shared between the REPL and SPI
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// flash. Both uses must block each other in order to prevent conflict.
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struct dma_resource audio_dma;
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struct dma_resource general_dma;
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void init_shared_dma(void) {
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struct dma_resource_config config;
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dma_get_config_defaults(&config);
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// This allocates the lowest channel first so make sure the audio is first
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// so it gets the highest priority.
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config.peripheral_trigger = DAC_DMAC_ID_EMPTY;
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config.trigger_action = DMA_TRIGGER_ACTION_BEAT;
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config.event_config.input_action = DMA_EVENT_INPUT_TRIG;
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dma_allocate(&audio_dma, &config);
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// Turn on the transfer complete interrupt so that the job_status changes to done.
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g_chan_interrupt_flag[audio_dma.channel_id] |= (1UL << DMA_CALLBACK_TRANSFER_DONE);
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dma_get_config_defaults(&config);
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dma_allocate(&general_dma, &config);
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// Be sneaky and reuse the active descriptor memory.
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audio_dma.descriptor = &descriptor_section[audio_dma.channel_id];
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general_dma.descriptor = &descriptor_section[general_dma.channel_id];
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}
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