4616df79f3
According to the documentation I have, DREQ pacing should be required here. The DREQ# hasn't changed since the BCM2835. As soon as we attempt to setup DREQ, DMA stalls and there's no clear reason why as of yet. Setting this back to NONE seems to work just as well, though it's yet to be determined if this is a sustainable model in high-throughput scenarios.
67 lines
2.4 KiB
C
67 lines
2.4 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2013 Daisuke Aoyama <aoyama@peach.ne.jp>
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* Copyright (c) 2013 Oleksandr Tymoshenko <gonzo@bluezbox.com>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef _BCM2835_DMA_H_
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#define _BCM2835_DMA_H_
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#define BCM_DMA_BLOCK_SIZE 512
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/* DMA0-DMA15 but DMA15 is special */
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#define BCM_DMA_CH_MAX 12
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/* request CH for any nubmer */
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#define BCM_DMA_CH_INVALID (-1)
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#define BCM_DMA_CH_ANY (-1)
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/* Peripheral DREQ Signals (4.2.1.3) */
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#define BCM_DMA_DREQ_NONE 0
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/*
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* XXX This doesn't seem to work for the Raspberry Pi 4, but the peripheral
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* documentation still lists it at 11.
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*/
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#define BCM_DMA_DREQ_EMMC 11
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#define BCM_DMA_DREQ_SDHOST 13
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#define BCM_DMA_SAME_ADDR 0
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#define BCM_DMA_INC_ADDR 1
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#define BCM_DMA_32BIT 0
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#define BCM_DMA_128BIT 1
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int bcm_dma_allocate(int req_ch);
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int bcm_dma_free(int ch);
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int bcm_dma_setup_intr(int ch, void (*func)(int, void *), void *arg);
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int bcm_dma_setup_src(int ch, int dreq, int inc_addr, int width);
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int bcm_dma_setup_dst(int ch, int dreq, int inc_addr, int width);
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int bcm_dma_start(int ch, vm_paddr_t src, vm_paddr_t dst, int len);
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uint32_t bcm_dma_length(int ch);
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#endif /* _BCM2835_DMA_H_ */
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