neorv32_dma.h

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// ================================================================================ //
// The NEORV32 RISC-V Processor - https://github.com/stnolting/neorv32              //
// Copyright (c) NEORV32 contributors.                                              //
// Copyright (c) 2020 - 2025 Stephan Nolting. All rights reserved.                  //
// Licensed under the BSD-3-Clause license, see LICENSE for details.                //
// SPDX-License-Identifier: BSD-3-Clause                                            //
// ================================================================================ //

 
#ifndef NEORV32_DMA_H
#define NEORV32_DMA_H
 
#include <stdint.h>
 
 
/**********************************************************************/
typedef volatile struct __attribute__((packed,aligned(4))) {
  uint32_t CTRL;     
  uint32_t SRC_BASE; 
  uint32_t DST_BASE; 
  uint32_t TTYPE;    
} neorv32_dma_t;

#define NEORV32_DMA ((neorv32_dma_t*) (NEORV32_DMA_BASE))

enum NEORV32_DMA_CTRL_enum {
  DMA_CTRL_EN           =  0, 
  DMA_CTRL_START        =  1, 
 
  DMA_CTRL_ERROR_RD     = 28, 
  DMA_CTRL_ERROR_WR     = 29, 
  DMA_CTRL_DONE         = 30, 
  DMA_CTRL_BUSY         = 31  
};

enum NEORV32_DMA_TTYPE_enum {
  DMA_TTYPE_NUM_LSB  =  0, 
  DMA_TTYPE_NUM_MSB  = 23, 
 
  DMA_TTYPE_QSEL_LSB = 27, 
  DMA_TTYPE_QSEL_MSB = 28, 
  DMA_TTYPE_SRC_INC  = 29, 
  DMA_TTYPE_DST_INC  = 30, 
  DMA_TTYPE_ENDIAN   = 31  
};

 
 
/**********************************************************************/
#define DMA_CMD_B2B  (0b00 << DMA_TTYPE_QSEL_LSB) // byte to byte
#define DMA_CMD_B2UW (0b01 << DMA_TTYPE_QSEL_LSB) // byte to unsigned word
#define DMA_CMD_B2SW (0b10 << DMA_TTYPE_QSEL_LSB) // byte to signed word
#define DMA_CMD_W2W  (0b11 << DMA_TTYPE_QSEL_LSB) // word to word
 
#define DMA_CMD_SRC_CONST (0b0 << DMA_TTYPE_SRC_INC) // constant source address
#define DMA_CMD_SRC_INC   (0b1 << DMA_TTYPE_SRC_INC) // incrementing source address
 
#define DMA_CMD_DST_CONST (0b0 << DMA_TTYPE_DST_INC) // constant destination address
#define DMA_CMD_DST_INC   (0b1 << DMA_TTYPE_DST_INC) // incrementing destination address
 
#define DMA_CMD_ENDIAN (0b1 << DMA_TTYPE_ENDIAN) // convert endianness
 
 
/**********************************************************************/
enum NEORV32_DMA_STATUS_enum {
  DMA_STATUS_ERR_WR = -2, 
  DMA_STATUS_ERR_RD = -1, 
  DMA_STATUS_IDLE   =  0, 
  DMA_STATUS_BUSY   =  1, 
  DMA_STATUS_DONE   =  2  
};
 
 
/**********************************************************************/
typedef struct __attribute__((packed,aligned(4))) {
  uint32_t src; 
  uint32_t dst; 
  uint32_t num; 
  uint32_t cmd; 
} neorv32_dma_desc_t;
 
 
/**********************************************************************/
int  neorv32_dma_available(void);
void neorv32_dma_enable(void);
void neorv32_dma_disable(void);
void neorv32_dma_transfer(neorv32_dma_desc_t *desc);
int  neorv32_dma_status(void);
 
 
#endif // NEORV32_DMA_H