1/* $NetBSD: fdt_dma.c,v 1.4 2019/02/27 16:56:00 jakllsch Exp $ */
2
3/*-
4 * Copyright (c) 2015 Jared D. 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.c,v 1.4 2019/02/27 16:56:00 jakllsch Exp $");
31
32#include <sys/param.h>
33#include <sys/bus.h>
34#include <sys/kmem.h>
35#include <sys/queue.h>
36
37#include <libfdt.h>
38#include <dev/fdt/fdtvar.h>
39
40struct fdtbus_dma_controller {
41	device_t dma_dev;
42	int dma_phandle;
43	const struct fdtbus_dma_controller_func *dma_funcs;
44
45	LIST_ENTRY(fdtbus_dma_controller) dma_next;
46};
47
48static LIST_HEAD(, fdtbus_dma_controller) fdtbus_dma_controllers =
49    LIST_HEAD_INITIALIZER(fdtbus_dma_controllers);
50
51int
52fdtbus_register_dma_controller(device_t dev, int phandle,
53    const struct fdtbus_dma_controller_func *funcs)
54{
55	struct fdtbus_dma_controller *dma;
56
57	dma = kmem_alloc(sizeof(*dma), KM_SLEEP);
58	dma->dma_dev = dev;
59	dma->dma_phandle = phandle;
60	dma->dma_funcs = funcs;
61
62	LIST_INSERT_HEAD(&fdtbus_dma_controllers, dma, dma_next);
63
64	return 0;
65}
66
67static struct fdtbus_dma_controller *
68fdtbus_get_dma_controller(int phandle)
69{
70	struct fdtbus_dma_controller *dma;
71
72	LIST_FOREACH(dma, &fdtbus_dma_controllers, dma_next) {
73		if (dma->dma_phandle == phandle)
74			return dma;
75	}
76
77	return NULL;
78}
79
80struct fdtbus_dma *
81fdtbus_dma_get_index(int phandle, u_int index, void (*cb)(void *), void *cbarg)
82{
83	struct fdtbus_dma_controller *dc;
84	struct fdtbus_dma *dma = NULL;
85	void *dma_priv = NULL;
86	uint32_t *dmas = NULL;
87	uint32_t *p;
88	u_int n, dma_cells;
89	int len, resid;
90
91	len = OF_getproplen(phandle, "dmas");
92	if (len <= 0)
93		return NULL;
94
95	dmas = kmem_alloc(len, KM_SLEEP);
96	if (OF_getprop(phandle, "dmas", dmas, len) != len) {
97		kmem_free(dmas, len);
98		return NULL;
99	}
100
101	p = dmas;
102	for (n = 0, resid = len; resid > 0; n++) {
103		const int dc_phandle =
104		    fdtbus_get_phandle_from_native(be32toh(p[0]));
105		if (of_getprop_uint32(dc_phandle, "#dma-cells", &dma_cells))
106			break;
107		if (n == index) {
108			dc = fdtbus_get_dma_controller(dc_phandle);
109			if (dc == NULL)
110				goto done;
111			dma_priv = dc->dma_funcs->acquire(dc->dma_dev,
112			    dma_cells > 0 ? &p[1] : NULL, dma_cells * 4,
113			    cb, cbarg);
114			if (dma_priv) {
115				dma = kmem_alloc(sizeof(*dma), KM_SLEEP);
116				dma->dma_dc = dc;
117				dma->dma_priv = dma_priv;
118			}
119			break;
120		}
121		resid -= (dma_cells + 1) * 4;
122		p += dma_cells + 1;
123	}
124
125done:
126	if (dmas)
127		kmem_free(dmas, len);
128
129	return dma;
130}
131
132struct fdtbus_dma *
133fdtbus_dma_get(int phandle, const char *name, void (*cb)(void *), void *cbarg)
134{
135	u_int index;
136	int err;
137
138	err = fdtbus_get_index(phandle, "dma-names", name, &index);
139	if (err != 0)
140		return NULL;
141
142	return fdtbus_dma_get_index(phandle, index, cb, cbarg);
143}
144
145void
146fdtbus_dma_put(struct fdtbus_dma *dma)
147{
148	struct fdtbus_dma_controller *dc = dma->dma_dc;
149
150	dc->dma_funcs->release(dc->dma_dev, dma->dma_priv);
151	kmem_free(dma, sizeof(*dma));
152}
153
154int
155fdtbus_dma_transfer(struct fdtbus_dma *dma, struct fdtbus_dma_req *req)
156{
157	struct fdtbus_dma_controller *dc = dma->dma_dc;
158
159	return dc->dma_funcs->transfer(dc->dma_dev, dma->dma_priv, req);
160}
161
162void
163fdtbus_dma_halt(struct fdtbus_dma *dma)
164{
165	struct fdtbus_dma_controller *dc = dma->dma_dc;
166
167	return dc->dma_funcs->halt(dc->dma_dev, dma->dma_priv);
168}
169