fdt_dma_machdep.c revision 1.1 
1/* $NetBSD: fdt_dma_machdep.c,v 1.1 2020/07/16 11:49:38 jmcneill Exp $ */
2
3/*-
4 * Copyright (c) 2020 Jared McNeill <jmcneill@invisible.ca>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__KERNEL_RCSID(0, "$NetBSD: fdt_dma_machdep.c,v 1.1 2020/07/16 11:49:38 jmcneill Exp $");
31
32#define	_MIPS_BUS_DMA_PRIVATE
33
34#include <sys/param.h>
35#include <sys/bus.h>
36#include <sys/kmem.h>
37
38#include <dev/fdt/fdtvar.h>
39
40static struct mips_bus_dma_tag fdtbus_dma_tag = {
41	._cookie = NULL,
42	._wbase = 0,
43	._bounce_alloc_lo = 0,
44	._bounce_alloc_hi = 0,
45	._dmamap_ops = _BUS_DMAMAP_OPS_INITIALIZER,
46	._dmamem_ops = _BUS_DMAMEM_OPS_INITIALIZER,
47	._dmatag_ops = _BUS_DMATAG_OPS_INITIALIZER,
48};
49
50bus_dma_tag_t
51fdtbus_dma_tag_create(int phandle, const struct fdt_dma_range *ranges,
52    u_int nranges)
53{
54	bus_dma_tag_t newtag;
55	bus_addr_t min_addr, max_addr;
56	int error;
57
58	if (nranges == 0)
59		return &fdtbus_dma_tag;
60
61	KASSERT(nranges == 1);
62	KASSERT(ranges[0].dr_sysbase == ranges[0].dr_busbase);
63
64	min_addr = ranges[0].dr_sysbase;
65	max_addr = min_addr + ranges[0].dr_len - 1;
66	error = bus_dmatag_subregion(&fdtbus_dma_tag, min_addr, max_addr,
67	    &newtag, 0);
68	KASSERT(error == 0);
69
70	return newtag;
71}
72