forked from Imagelibrary/rtems
133 lines
4.7 KiB
C
133 lines
4.7 KiB
C
/* SPDX-License-Identifier: BSD-2-Clause */
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/**
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* @file
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*
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* @ingroup RTEMSBSPsAArch64Raspberrypi4
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*
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* @brief Raspberry Pi specific DMA definitions.
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*/
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/*
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* Copyright (C) 2025 Shaunak Datar
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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 COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND 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 COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef LIBBSP_AARCH64_RASPBERRYPI_DMA_H
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#define LIBBSP_AARCH64_RASPBERRYPI_DMA_H
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#include <bsp/raspberrypi.h>
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#include <bsp/rpi-gpio.h>
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#include <bsp/utility.h>
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#include <rtems/malloc.h>
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#include <rtems/rtems/cache.h>
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#include <rtems/score/basedefs.h>
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#include <rtems/score/cpu.h>
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#include <stdlib.h>
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#include <string.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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/**
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* @brief DMA channel identifiers for BCM2711 (0–6 full, 7–10 lite, 11–14 DMA4).
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*/
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typedef enum {
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DMA_CHANNEL_0,
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DMA_CHANNEL_1,
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DMA_CHANNEL_2,
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DMA_CHANNEL_3,
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DMA_CHANNEL_4,
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DMA_CHANNEL_5,
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DMA_CHANNEL_6,
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DMA_LITE_CHANNEL_7,
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DMA_LITE_CHANNEL_8,
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DMA_LITE_CHANNEL_9,
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DMA_LITE_CHANNEL_10,
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DMA4_CHANNEL_11,
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DMA4_CHANNEL_12,
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DMA4_CHANNEL_13,
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DMA4_CHANNEL_14,
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} rpi_dma_channel;
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/**
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* @brief Start a previously initialized DMA transfer on @a channel.
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*
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* Expects the channel's CONBLK_AD to point to a valid
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* control block. Sets ACTIVE and required priorities.
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*
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* @param channel DMA channel to start.
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* @retval RTEMS_SUCCESSFUL on success.
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* @retval RTEMS_INVALID_NUMBER if @a channel is invalid.
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*/
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rtems_status_code rpi_dma_start_transfer( rpi_dma_channel channel );
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/**
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* @brief Block until the current DMA transfer on @a channel completes.
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*
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* Busy-waits for ACTIVE to clear and frees the control block previously
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* programmed into CONBLK_AD (including DMA4 address unshifting). Does **not**
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* invalidate/flush user buffers beyond setup done by the init helpers.
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*
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* @param channel DMA channel to wait on.
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* @retval RTEMS_SUCCESSFUL on success.
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* @retval RTEMS_INVALID_NUMBER if @a channel is invalid.
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* @retval RTEMS_UNSATISFIED if the channel reports an error.
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*/
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rtems_status_code rpi_dma_wait( rpi_dma_channel channel );
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/**
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* @brief Initialize a memcpy-style DMA transfer from @a source_address to
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* @a destination_address of @a transfer_length bytes on @a channel.
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*
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* Allocates and prepares the channel-specific control block, performs required
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* cache maintenance (flush control block and source; invalidate destination),
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* issues CS reset/abort, and writes CONBLK_AD (with DMA4 address packing via
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* DMA4_AD_SHIFT). This function does **not** start the transfer; call
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* ::rpi_dma_start_transfer() and then ::rpi_dma_wait().
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*
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* @param channel DMA channel to use (0–6 noarmal DMA, 7–10 lite,
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* 11–14 DMA4).
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* @param source_address Source buffer (must be CPU_CACHE_LINE_BYTES
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* aligned).
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* @param destination_address Destination buffer (must be CPU_CACHE_LINE_BYTES
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* aligned).
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* @param transfer_length Number of bytes to copy.
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* @retval RTEMS_SUCCESSFUL on success.
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* @retval RTEMS_INVALID_NUMBER if @a channel is invalid/unsupported or has
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* no base address.
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* @retval RTEMS_INVALID_ADDRESS if @a source_address or @a
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* destination_address are misaligned.
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* @retval RTEMS_NO_MEMORY if control block allocation failed.
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*/
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rtems_status_code rpi_dma_mem_to_mem_init(
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rpi_dma_channel channel,
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void *source_address,
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void *destination_address,
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uint32_t transfer_length
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);
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#ifdef __cplusplus
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}
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#endif
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#endif /* LIBBSP_AARCH64_RASPBERRYPI_DMA_H */ |