/* SPDX-License-Identifier: GPL-2.0-only */ /* * arch/arm/include/asm/mach/dma.h * * Copyright (C) 1998-2000 Russell King * * This header file describes the interface between the generic DMA handler * (dma.c) and the architecture-specific DMA backends (dma-*.c) */ struct dma_struct; typedef struct dma_struct dma_t; struct dma_ops { int (*request)(unsigned int, dma_t *); /* optional */ void (*free)(unsigned int, dma_t *); /* optional */ void (*enable)(unsigned int, dma_t *); /* mandatory */ void (*disable)(unsigned int, dma_t *); /* mandatory */ int (*residue)(unsigned int, dma_t *); /* optional */ int (*setspeed)(unsigned int, dma_t *, int); /* optional */ const char *type; }; struct dma_struct { void *addr; /* single DMA address */ unsigned long count; /* single DMA size */ struct scatterlist buf; /* single DMA */ int sgcount; /* number of DMA SG */ struct scatterlist *sg; /* DMA Scatter-Gather List */ unsigned int active:1; /* Transfer active */ unsigned int invalid:1; /* Address/Count changed */ unsigned int dma_mode; /* DMA mode */ int speed; /* DMA speed */ unsigned int lock; /* Device is allocated */ const char *device_id; /* Device name */ const struct dma_ops *d_ops; }; /* * isa_dma_add - add an ISA-style DMA channel */ extern int isa_dma_add(unsigned int, dma_t *dma);