1 /* 2 * Copyright (c) 2016, Xilinx Inc. and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 /* 8 * @file dma.h 9 * @brief DMA primitives for libmetal. 10 */ 11 12 #ifndef __METAL_DMA__H__ 13 #define __METAL_DMA__H__ 14 15 #include <stdint.h> 16 #include <metal/sys.h> 17 18 #ifdef __cplusplus 19 extern "C" { 20 #endif 21 22 /** \defgroup dma DMA Interfaces 23 * @{ 24 */ 25 26 #define METAL_DMA_DEV_R 1 /**< DMA direction, device read */ 27 #define METAL_DMA_DEV_W 2 /**< DMA direction, device write */ 28 #define METAL_DMA_DEV_WR 3 /**< DMA direction, device read/write */ 29 30 /** 31 * @brief scatter/gather list element structure 32 */ 33 struct metal_sg { 34 void *virt; /**< CPU virtual address */ 35 struct metal_io_region *io; /**< IO region */ 36 int len; /**< length */ 37 }; 38 39 struct metal_device; 40 41 /** 42 * @brief Map memory for DMA transaction. 43 * After the memory is DMA mapped, the memory should be 44 * accessed by the DMA device but not the CPU. 45 * 46 * @param[in] dev DMA device 47 * @param[in] dir DMA direction 48 * @param[in] sg_in sg list of memory to map 49 * @param[in] nents_in number of sg list entries of memory to map 50 * @param[out] sg_out sg list of mapped memory 51 * @return number of mapped sg entries, -error on failure. 52 */ 53 int metal_dma_map(struct metal_device *dev, 54 uint32_t dir, 55 struct metal_sg *sg_in, 56 int nents_in, 57 struct metal_sg *sg_out); 58 59 /** 60 * @brief Unmap DMA memory 61 * After the memory is DMA unmapped, the memory should 62 * be accessed by the CPU but not the DMA device. 63 * 64 * @param[in] dev DMA device 65 * @param[in] dir DMA direction 66 * @param[in] sg sg list of mapped DMA memory 67 * @param[in] nents number of sg list entries of DMA memory 68 */ 69 void metal_dma_unmap(struct metal_device *dev, 70 uint32_t dir, 71 struct metal_sg *sg, 72 int nents); 73 74 /** @} */ 75 76 #ifdef __cplusplus 77 } 78 #endif 79 80 #endif /* __METAL_DMA__H__ */ 81
