1/* $NetBSD: fdt_reset.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_reset.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_reset_controller {
41	device_t rc_dev;
42	int rc_phandle;
43	const struct fdtbus_reset_controller_func *rc_funcs;
44
45	LIST_ENTRY(fdtbus_reset_controller) rc_next;
46};
47
48static LIST_HEAD(, fdtbus_reset_controller) fdtbus_reset_controllers =
49    LIST_HEAD_INITIALIZER(fdtbus_reset_controllers);
50
51int
52fdtbus_register_reset_controller(device_t dev, int phandle,
53    const struct fdtbus_reset_controller_func *funcs)
54{
55	struct fdtbus_reset_controller *rc;
56
57	rc = kmem_alloc(sizeof(*rc), KM_SLEEP);
58	rc->rc_dev = dev;
59	rc->rc_phandle = phandle;
60	rc->rc_funcs = funcs;
61
62	LIST_INSERT_HEAD(&fdtbus_reset_controllers, rc, rc_next);
63
64	return 0;
65}
66
67static struct fdtbus_reset_controller *
68fdtbus_get_reset_controller(int phandle)
69{
70	struct fdtbus_reset_controller *rc;
71
72	LIST_FOREACH(rc, &fdtbus_reset_controllers, rc_next) {
73		if (rc->rc_phandle == phandle)
74			return rc;
75	}
76
77	return NULL;
78}
79
80struct fdtbus_reset *
81fdtbus_reset_get_index(int phandle, u_int index)
82{
83	struct fdtbus_reset_controller *rc;
84	struct fdtbus_reset *rst = NULL;
85	void *rst_priv = NULL;
86	uint32_t *resets = NULL;
87	uint32_t *p;
88	u_int n, reset_cells;
89	int len, resid;
90
91	len = OF_getproplen(phandle, "resets");
92	if (len <= 0)
93		return NULL;
94
95	resets = kmem_alloc(len, KM_SLEEP);
96	if (OF_getprop(phandle, "resets", resets, len) != len) {
97		kmem_free(resets, len);
98		return NULL;
99	}
100
101	p = resets;
102	for (n = 0, resid = len; resid > 0; n++) {
103		const int rc_phandle =
104		    fdtbus_get_phandle_from_native(be32toh(p[0]));
105		if (of_getprop_uint32(rc_phandle, "#reset-cells", &reset_cells))
106			break;
107		if (n == index) {
108			rc = fdtbus_get_reset_controller(rc_phandle);
109			if (rc == NULL)
110				goto done;
111			rst_priv = rc->rc_funcs->acquire(rc->rc_dev,
112			    reset_cells > 0 ? &p[1] : NULL, reset_cells * 4);
113			if (rst_priv) {
114				rst = kmem_alloc(sizeof(*rst), KM_SLEEP);
115				rst->rst_rc = rc;
116				rst->rst_priv = rst_priv;
117			}
118			break;
119		}
120		resid -= (reset_cells + 1) * 4;
121		p += reset_cells + 1;
122	}
123
124done:
125	if (resets)
126		kmem_free(resets, len);
127
128	return rst;
129}
130
131struct fdtbus_reset *
132fdtbus_reset_get(int phandle, const char *rstname)
133{
134	u_int index;
135	int err;
136
137	err = fdtbus_get_index(phandle, "reset-names", rstname, &index);
138	if (err != 0)
139		return NULL;
140
141	return fdtbus_reset_get_index(phandle, index);
142}
143
144void
145fdtbus_reset_put(struct fdtbus_reset *rst)
146{
147	struct fdtbus_reset_controller *rc = rst->rst_rc;
148
149	rc->rc_funcs->release(rc->rc_dev, rst->rst_priv);
150	kmem_free(rst, sizeof(*rst));
151}
152
153int
154fdtbus_reset_assert(struct fdtbus_reset *rst)
155{
156	struct fdtbus_reset_controller *rc = rst->rst_rc;
157
158	return rc->rc_funcs->reset_assert(rc->rc_dev, rst->rst_priv);
159}
160
161int
162fdtbus_reset_deassert(struct fdtbus_reset *rst)
163{
164	struct fdtbus_reset_controller *rc = rst->rst_rc;
165
166	return rc->rc_funcs->reset_deassert(rc->rc_dev, rst->rst_priv);
167}
168