1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2020 Andrew Turner
5 *
6 * This work was supported by Innovate UK project 105694, "Digital Security
7 * by Design (DSbD) Technology Platform Prototype".
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/param.h>
32#include <sys/systm.h>
33#include <sys/bus.h>
34#include <sys/kernel.h>
35#include <sys/module.h>
36#include <sys/sysctl.h>
37
38#include <dev/fdt/simplebus.h>
39
40#include <dev/ofw/ofw_bus.h>
41#include <dev/ofw/ofw_bus_subr.h>
42
43#include <arm/broadcom/bcm2835/bcm2835_firmware.h>
44#include <arm/broadcom/bcm2835/bcm2835_mbox.h>
45#include <arm/broadcom/bcm2835/bcm2835_mbox_prop.h>
46#include <arm/broadcom/bcm2835/bcm2835_vcbus.h>
47
48struct bcm2835_firmware_softc {
49	struct simplebus_softc	sc;
50	phandle_t	sc_mbox;
51};
52
53static struct ofw_compat_data compat_data[] = {
54	{"raspberrypi,bcm2835-firmware",	1},
55	{NULL,					0}
56};
57
58static int sysctl_bcm2835_firmware_get_revision(SYSCTL_HANDLER_ARGS);
59
60static int
61bcm2835_firmware_probe(device_t dev)
62{
63	if (!ofw_bus_status_okay(dev))
64		return (ENXIO);
65
66	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
67		return (ENXIO);
68
69	device_set_desc(dev, "BCM2835 Firmware");
70	return (BUS_PROBE_DEFAULT);
71}
72
73static int
74bcm2835_firmware_attach(device_t dev)
75{
76	struct bcm2835_firmware_softc *sc;
77	struct sysctl_ctx_list *ctx;
78	struct sysctl_oid *tree_node;
79	struct sysctl_oid_list *tree;
80	phandle_t node, mbox;
81	int rv;
82
83	sc = device_get_softc(dev);
84
85	node = ofw_bus_get_node(dev);
86	rv = OF_getencprop(node, "mboxes", &mbox, sizeof(mbox));
87	if (rv <= 0) {
88		device_printf(dev, "can't read mboxes property\n");
89		return (ENXIO);
90	}
91	sc->sc_mbox = mbox;
92
93	OF_device_register_xref(OF_xref_from_node(node), dev);
94
95	ctx = device_get_sysctl_ctx(dev);
96	tree_node = device_get_sysctl_tree(dev);
97	tree = SYSCTL_CHILDREN(tree_node);
98	SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "revision",
99	    CTLTYPE_UINT | CTLFLAG_RD, sc, sizeof(*sc),
100	    sysctl_bcm2835_firmware_get_revision, "IU",
101	    "Firmware revision");
102
103	/* The firmwaare doesn't have a ranges property */
104	sc->sc.flags |= SB_FLAG_NO_RANGES;
105	return (simplebus_attach(dev));
106}
107
108int
109bcm2835_firmware_property(device_t dev, uint32_t prop, void *data, size_t len)
110{
111	struct {
112		struct bcm2835_mbox_hdr hdr;
113		struct bcm2835_mbox_tag_hdr tag_hdr;
114		uint32_t data[];
115	} *msg_hdr;
116	size_t msg_len;
117	int err;
118
119	/*
120	 * The message is processed in 32-bit chunks so must be a multiple
121	 * of 32-bits.
122	 */
123	if ((len & (sizeof(uint32_t) - 1)) != 0)
124		return (EINVAL);
125
126	msg_len = sizeof(*msg_hdr) + len + sizeof(uint32_t);
127	msg_hdr = malloc(sizeof(*msg_hdr) + msg_len + sizeof(uint32_t),
128	    M_DEVBUF, M_WAITOK | M_ZERO);
129
130	msg_hdr->hdr.buf_size = msg_len;
131	msg_hdr->hdr.code = BCM2835_MBOX_CODE_REQ;
132	msg_hdr->tag_hdr.tag = prop;
133	msg_hdr->tag_hdr.val_buf_size = len;
134	memcpy(msg_hdr->data, data, len);
135	msg_hdr->data[len / sizeof(uint32_t)] = 0;
136
137	err = bcm2835_mbox_property(msg_hdr, msg_len);
138	if (err == 0) {
139		memcpy(data, msg_hdr->data, len);
140	}
141
142	free(msg_hdr, M_DEVBUF);
143
144	return (err);
145}
146
147static int
148sysctl_bcm2835_firmware_get_revision(SYSCTL_HANDLER_ARGS)
149{
150	struct bcm2835_firmware_softc *sc = arg1;
151	uint32_t rev;
152	int err;
153
154	if (bcm2835_firmware_property(sc->sc.dev,
155	    BCM2835_MBOX_TAG_FIRMWARE_REVISION, &rev, sizeof(rev)) != 0)
156		return (ENXIO);
157
158	err = sysctl_handle_int(oidp, &rev, sizeof(rev), req);
159	if (err || !req->newptr) /* error || read request */
160		return (err);
161
162	/* write request */
163	return (EINVAL);
164}
165
166static device_method_t bcm2835_firmware_methods[] = {
167	/* Device interface */
168	DEVMETHOD(device_probe,		bcm2835_firmware_probe),
169	DEVMETHOD(device_attach,	bcm2835_firmware_attach),
170
171	DEVMETHOD_END
172};
173
174DEFINE_CLASS_1(bcm2835_firmware, bcm2835_firmware_driver,
175    bcm2835_firmware_methods, sizeof(struct bcm2835_firmware_softc),
176    simplebus_driver);
177
178EARLY_DRIVER_MODULE(bcm2835_firmware, simplebus, bcm2835_firmware_driver, 0, 0,
179    BUS_PASS_BUS + BUS_PASS_ORDER_LATE);
180MODULE_DEPEND(bcm2835_firmware, mbox, 1, 1, 1);
181