xref: /freebsd/sys/arm/broadcom/bcm2835/bcm2835_firmware.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
39 #include <sys/sysctl.h>
40 
41 #include <dev/fdt/simplebus.h>
42 
43 #include <dev/ofw/ofw_bus.h>
44 #include <dev/ofw/ofw_bus_subr.h>
45 
46 #include <arm/broadcom/bcm2835/bcm2835_firmware.h>
47 #include <arm/broadcom/bcm2835/bcm2835_mbox.h>
48 #include <arm/broadcom/bcm2835/bcm2835_mbox_prop.h>
49 #include <arm/broadcom/bcm2835/bcm2835_vcbus.h>
50 
51 struct bcm2835_firmware_softc {
52 	struct simplebus_softc	sc;
53 	phandle_t	sc_mbox;
54 };
55 
56 static struct ofw_compat_data compat_data[] = {
57 	{"raspberrypi,bcm2835-firmware",	1},
58 	{NULL,					0}
59 };
60 
61 static int sysctl_bcm2835_firmware_get_revision(SYSCTL_HANDLER_ARGS);
62 
63 static int
64 bcm2835_firmware_probe(device_t dev)
65 {
66 	if (!ofw_bus_status_okay(dev))
67 		return (ENXIO);
68 
69 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
70 		return (ENXIO);
71 
72 	device_set_desc(dev, "BCM2835 Firmware");
73 	return (BUS_PROBE_DEFAULT);
74 }
75 
76 static int
77 bcm2835_firmware_attach(device_t dev)
78 {
79 	struct bcm2835_firmware_softc *sc;
80 	struct sysctl_ctx_list *ctx;
81 	struct sysctl_oid *tree_node;
82 	struct sysctl_oid_list *tree;
83 	phandle_t node, mbox;
84 	int rv;
85 
86 	sc = device_get_softc(dev);
87 
88 	node = ofw_bus_get_node(dev);
89 	rv = OF_getencprop(node, "mboxes", &mbox, sizeof(mbox));
90 	if (rv <= 0) {
91 		device_printf(dev, "can't read mboxes property\n");
92 		return (ENXIO);
93 	}
94 	sc->sc_mbox = mbox;
95 
96 	OF_device_register_xref(OF_xref_from_node(node), dev);
97 
98 	ctx = device_get_sysctl_ctx(dev);
99 	tree_node = device_get_sysctl_tree(dev);
100 	tree = SYSCTL_CHILDREN(tree_node);
101 	SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "revision",
102 	    CTLTYPE_UINT | CTLFLAG_RD, sc, sizeof(*sc),
103 	    sysctl_bcm2835_firmware_get_revision, "IU",
104 	    "Firmware revision");
105 
106 	/* The firmwaare doesn't have a ranges property */
107 	sc->sc.flags |= SB_FLAG_NO_RANGES;
108 	return (simplebus_attach(dev));
109 }
110 
111 int
112 bcm2835_firmware_property(device_t dev, uint32_t prop, void *data, size_t len)
113 {
114 	struct {
115 		struct bcm2835_mbox_hdr hdr;
116 		struct bcm2835_mbox_tag_hdr tag_hdr;
117 		uint32_t data[];
118 	} *msg_hdr;
119 	size_t msg_len;
120 	int err;
121 
122 	/*
123 	 * The message is processed in 32-bit chunks so must be a multiple
124 	 * of 32-bits.
125 	 */
126 	if ((len & (sizeof(uint32_t) - 1)) != 0)
127 		return (EINVAL);
128 
129 	msg_len = sizeof(*msg_hdr) + len + sizeof(uint32_t);
130 	msg_hdr = malloc(sizeof(*msg_hdr) + msg_len + sizeof(uint32_t),
131 	    M_DEVBUF, M_WAITOK | M_ZERO);
132 
133 	msg_hdr->hdr.buf_size = msg_len;
134 	msg_hdr->hdr.code = BCM2835_MBOX_CODE_REQ;
135 	msg_hdr->tag_hdr.tag = prop;
136 	msg_hdr->tag_hdr.val_buf_size = len;
137 	memcpy(msg_hdr->data, data, len);
138 	msg_hdr->data[len / sizeof(uint32_t)] = 0;
139 
140 	err = bcm2835_mbox_property(msg_hdr, msg_len);
141 	if (err == 0) {
142 		memcpy(data, msg_hdr->data, len);
143 	}
144 
145 	free(msg_hdr, M_DEVBUF);
146 
147 	return (err);
148 }
149 
150 static int
151 sysctl_bcm2835_firmware_get_revision(SYSCTL_HANDLER_ARGS)
152 {
153 	struct bcm2835_firmware_softc *sc = arg1;
154 	uint32_t rev;
155 	int err;
156 
157 	if (bcm2835_firmware_property(sc->sc.dev,
158 	    BCM2835_MBOX_TAG_FIRMWARE_REVISION, &rev, sizeof(rev)) != 0)
159 		return (ENXIO);
160 
161 	err = sysctl_handle_int(oidp, &rev, sizeof(rev), req);
162 	if (err || !req->newptr) /* error || read request */
163 		return (err);
164 
165 	/* write request */
166 	return (EINVAL);
167 }
168 
169 static device_method_t bcm2835_firmware_methods[] = {
170 	/* Device interface */
171 	DEVMETHOD(device_probe,		bcm2835_firmware_probe),
172 	DEVMETHOD(device_attach,	bcm2835_firmware_attach),
173 
174 	DEVMETHOD_END
175 };
176 
177 static devclass_t bcm2835_firmware_devclass;
178 DEFINE_CLASS_1(bcm2835_firmware, bcm2835_firmware_driver,
179     bcm2835_firmware_methods, sizeof(struct bcm2835_firmware_softc),
180     simplebus_driver);
181 
182 EARLY_DRIVER_MODULE(bcm2835_firmware, simplebus, bcm2835_firmware_driver,
183     bcm2835_firmware_devclass, 0, 0, BUS_PASS_BUS + BUS_PASS_ORDER_LATE);
184 MODULE_DEPEND(bcm2835_firmware, mbox, 1, 1, 1);
185