1/* $NetBSD: fdt_mbox.c,v 1.1 2022/03/04 08:19:06 skrll Exp $ */
2
3/*-
4 * Copyright (c) 2022 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Nick Hudson
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__KERNEL_RCSID(0, "$NetBSD: fdt_mbox.c,v 1.1 2022/03/04 08:19:06 skrll Exp $");
34
35#include <sys/param.h>
36
37#include <sys/bus.h>
38#include <sys/kmem.h>
39#include <sys/queue.h>
40
41#include <libfdt.h>
42#include <dev/fdt/fdtvar.h>
43
44
45struct fdtbus_mbox_controller {
46	device_t mc_dev;
47	int mc_phandle;
48
49	int mc_cells;
50
51	const struct fdtbus_mbox_controller_func *mc_funcs;
52
53	LIST_ENTRY(fdtbus_mbox_controller) mc_next;
54};
55
56static LIST_HEAD(, fdtbus_mbox_controller) fdtbus_mbox_controllers =
57    LIST_HEAD_INITIALIZER(fdtbus_mbox_controllers);
58
59int
60fdtbus_register_mbox_controller(device_t dev, int phandle,
61    const struct fdtbus_mbox_controller_func *funcs)
62{
63	struct fdtbus_mbox_controller *mc;
64
65	uint32_t cells;
66	if (of_getprop_uint32(phandle, "#mbox-cells", &cells) != 0) {
67		aprint_debug_dev(dev, "missing #mbox-cells");
68		return EINVAL;
69	}
70
71	mc = kmem_alloc(sizeof(*mc), KM_SLEEP);
72	mc->mc_dev = dev;
73	mc->mc_phandle = phandle;
74	mc->mc_funcs = funcs;
75	mc->mc_cells = cells;
76
77	LIST_INSERT_HEAD(&fdtbus_mbox_controllers, mc, mc_next);
78
79	return 0;
80}
81
82static struct fdtbus_mbox_controller *
83fdtbus_mbox_lookup(int phandle)
84{
85	struct fdtbus_mbox_controller *mc;
86
87	LIST_FOREACH(mc, &fdtbus_mbox_controllers, mc_next) {
88		if (mc->mc_phandle == phandle)
89			return mc;
90	}
91
92	return NULL;
93}
94
95struct fdtbus_mbox_channel *
96fdtbus_mbox_get_index(int phandle, u_int index, void (*cb)(void *), void *cbarg)
97{
98	struct fdtbus_mbox_controller *mc;
99	struct fdtbus_mbox_channel *mbox = NULL;
100	void *mbox_priv = NULL;
101	uint32_t *mboxes = NULL;
102	uint32_t *p;
103	u_int n;
104	int len, resid;
105
106	len = OF_getproplen(phandle, "mboxes");
107	if (len <= 0)
108		return NULL;
109
110	mboxes = kmem_alloc(len, KM_SLEEP);
111	if (OF_getprop(phandle, "mboxes", mboxes, len) != len) {
112		kmem_free(mboxes, len);
113		return NULL;
114	}
115
116	p = mboxes;
117	for (n = 0, resid = len; resid > 0; n++) {
118		const int mc_phandle =
119		    fdtbus_get_phandle_from_native(be32toh(p[0]));
120
121		mc = fdtbus_mbox_lookup(mc_phandle);
122		if (mc == NULL)
123			break;
124
125		u_int mbox_cells = mc->mc_cells;
126		if (n == index) {
127			mbox_priv = mc->mc_funcs->mc_acquire(mc->mc_dev,
128			    mbox_cells > 0 ? &p[1] : NULL, mbox_cells * 4,
129			    cb, cbarg);
130			if (mbox_priv) {
131				mbox = kmem_alloc(sizeof(*mbox), KM_SLEEP);
132				mbox->mb_ctlr = mc;
133				mbox->mb_priv = mbox_priv;
134			}
135			break;
136		}
137		resid -= (mbox_cells + 1) * 4;
138		p += mbox_cells + 1;
139	}
140
141	if (mboxes)
142		kmem_free(mboxes, len);
143
144	return mbox;
145}
146
147struct fdtbus_mbox_channel *
148fdtbus_mbox_get(int phandle, const char *name, void (*cb)(void *), void *cbarg)
149{
150	u_int index;
151	int err;
152
153	err = fdtbus_get_index(phandle, "mbox-names", name, &index);
154	if (err != 0)
155		return NULL;
156
157	return fdtbus_mbox_get_index(phandle, index, cb, cbarg);
158}
159
160void
161fdtbus_mbox_put(struct fdtbus_mbox_channel *mbox)
162{
163	struct fdtbus_mbox_controller *mc = mbox->mb_ctlr;
164
165	mc->mc_funcs->mc_release(mc->mc_dev, mbox->mb_priv);
166	kmem_free(mbox, sizeof(*mbox));
167}
168
169int
170fdtbus_mbox_send(struct fdtbus_mbox_channel *mbox, const void *data, size_t len)
171{
172	struct fdtbus_mbox_controller * const mc = mbox->mb_ctlr;
173
174	return mc->mc_funcs->mc_send(mc->mc_dev, mbox->mb_priv, data, len);
175}
176
177int
178fdtbus_mbox_recv(struct fdtbus_mbox_channel *mbox, void *data, size_t len)
179{
180	struct fdtbus_mbox_controller * const mc = mbox->mb_ctlr;
181
182	return mc->mc_funcs->mc_recv(mc->mc_dev, mbox->mb_priv, data, len);
183}
184