xref: /freebsd/sys/arm/allwinner/aw_sid.c (revision 86c6868161803323de7c25bdf9749efd2f5e2dfc)
1 /*-
2  * Copyright (c) 2016 Jared McNeill <jmcneill@invisible.ca>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
19  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
21  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
22  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 /*
30  * Allwinner secure ID controller
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/endian.h>
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/bus.h>
40 #include <sys/rman.h>
41 #include <sys/kernel.h>
42 #include <sys/lock.h>
43 #include <sys/mutex.h>
44 #include <sys/module.h>
45 #include <sys/sysctl.h>
46 #include <machine/bus.h>
47 
48 #include <dev/ofw/ofw_bus.h>
49 #include <dev/ofw/ofw_bus_subr.h>
50 
51 #include <arm/allwinner/aw_sid.h>
52 
53 /* efuse registers */
54 #define	SID_PRCTL		0x40
55 #define	 SID_PRCTL_OFFSET_MASK	0xff
56 #define	 SID_PRCTL_OFFSET(n)	(((n) & SID_PRCTL_OFFSET_MASK) << 16)
57 #define	 SID_PRCTL_LOCK		(0xac << 8)
58 #define	 SID_PRCTL_READ		(0x01 << 1)
59 #define	 SID_PRCTL_WRITE	(0x01 << 0)
60 #define	SID_PRKEY		0x50
61 #define	SID_RDKEY		0x60
62 
63 #define	SID_SRAM		0x200
64 #define	SID_THERMAL_CALIB0	(SID_SRAM + 0x34)
65 #define	SID_THERMAL_CALIB1	(SID_SRAM + 0x38)
66 
67 #define	ROOT_KEY_SIZE		4
68 
69 struct aw_sid_conf {
70 	bus_size_t	rootkey_offset;
71 	bool		has_prctl;
72 	bool		has_thermal;
73 };
74 
75 static const struct aw_sid_conf a10_conf = {
76 	.rootkey_offset = 0,
77 };
78 
79 static const struct aw_sid_conf a20_conf = {
80 	.rootkey_offset = 0,
81 };
82 
83 static const struct aw_sid_conf a64_conf = {
84 	.rootkey_offset = SID_SRAM,
85 	.has_prctl = true,
86 	.has_thermal = true,
87 };
88 
89 static const struct aw_sid_conf a83t_conf = {
90 	.rootkey_offset = SID_SRAM,
91 	.has_prctl = true,
92 	.has_thermal = true,
93 };
94 
95 static struct ofw_compat_data compat_data[] = {
96 	{ "allwinner,sun4i-a10-sid",		(uintptr_t)&a10_conf},
97 	{ "allwinner,sun7i-a20-sid",		(uintptr_t)&a20_conf},
98 	{ "allwinner,sun50i-a64-sid",		(uintptr_t)&a64_conf},
99 	{ "allwinner,sun8i-a83t-sid",		(uintptr_t)&a83t_conf},
100 	{ NULL,					0 }
101 };
102 
103 struct aw_sid_softc {
104 	struct resource		*res;
105 	struct aw_sid_conf	*sid_conf;
106 	struct mtx		prctl_mtx;
107 };
108 
109 static struct aw_sid_softc *aw_sid_sc;
110 
111 static struct resource_spec aw_sid_spec[] = {
112 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
113 	{ -1, 0 }
114 };
115 
116 enum sid_keys {
117 	AW_SID_ROOT_KEY,
118 };
119 
120 #define	RD4(sc, reg)		bus_read_4((sc)->res, (reg))
121 #define	WR4(sc, reg, val)	bus_write_4((sc)->res, (reg), (val))
122 
123 static int aw_sid_sysctl(SYSCTL_HANDLER_ARGS);
124 static int aw_sid_prctl_read(device_t dev, bus_size_t offset, uint32_t *val);
125 
126 
127 /*
128  * offset here is offset into efuse space, rather than offset into sid register
129  * space. This form of read is only an option for newer SoC: A83t, H3, A64
130  */
131 static int
132 aw_sid_prctl_read(device_t dev, bus_size_t offset, uint32_t *val)
133 {
134 	struct aw_sid_softc *sc;
135 	uint32_t readval;
136 
137 	sc = device_get_softc(dev);
138 	if (!sc->sid_conf->has_prctl)
139 		return (1);
140 
141 	mtx_lock(&sc->prctl_mtx);
142 	readval = SID_PRCTL_OFFSET(offset) | SID_PRCTL_LOCK | SID_PRCTL_READ;
143 	WR4(sc, SID_PRCTL, readval);
144 	/* Read bit will be cleared once read has concluded */
145 	while (RD4(sc, SID_PRCTL) & SID_PRCTL_READ)
146 		continue;
147 	readval = RD4(sc, SID_RDKEY);
148 	mtx_unlock(&sc->prctl_mtx);
149 	*val = readval;
150 
151 	return (0);
152 }
153 
154 static int
155 aw_sid_probe(device_t dev)
156 {
157 	if (!ofw_bus_status_okay(dev))
158 		return (ENXIO);
159 
160 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
161 		return (ENXIO);
162 
163 	device_set_desc(dev, "Allwinner Secure ID Controller");
164 	return (BUS_PROBE_DEFAULT);
165 }
166 
167 static int
168 aw_sid_attach(device_t dev)
169 {
170 	struct aw_sid_softc *sc;
171 
172 	sc = device_get_softc(dev);
173 
174 	if (bus_alloc_resources(dev, aw_sid_spec, &sc->res) != 0) {
175 		device_printf(dev, "cannot allocate resources for device\n");
176 		return (ENXIO);
177 	}
178 
179 	mtx_init(&sc->prctl_mtx, device_get_nameunit(dev), NULL, MTX_DEF);
180 	sc->sid_conf = (struct aw_sid_conf *)ofw_bus_search_compatible(dev, compat_data)->ocd_data;
181 	aw_sid_sc = sc;
182 
183 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
184 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
185 	    OID_AUTO, "rootkey",
186 	    CTLTYPE_STRING | CTLFLAG_RD,
187 	    dev, AW_SID_ROOT_KEY, aw_sid_sysctl, "A", "Root Key");
188 
189 	return (0);
190 }
191 
192 int
193 aw_sid_read_tscalib(uint32_t *calib0, uint32_t *calib1)
194 {
195 	struct aw_sid_softc *sc;
196 
197 	sc = aw_sid_sc;
198 	if (sc == NULL)
199 		return (ENXIO);
200 	if (!sc->sid_conf->has_thermal)
201 		return (ENXIO);
202 
203 	*calib0 = RD4(sc, SID_THERMAL_CALIB0);
204 	*calib1 = RD4(sc, SID_THERMAL_CALIB1);
205 
206 	return (0);
207 }
208 
209 int
210 aw_sid_get_rootkey(u_char *out)
211 {
212 	struct aw_sid_softc *sc;
213 	int i;
214 	bus_size_t root_key_off;
215 	u_int tmp;
216 
217 	sc = aw_sid_sc;
218 	if (sc == NULL)
219 		return (ENXIO);
220 	root_key_off = aw_sid_sc->sid_conf->rootkey_offset;
221 	for (i = 0; i < ROOT_KEY_SIZE ; i++) {
222 		tmp = RD4(aw_sid_sc, root_key_off + (i * 4));
223 		be32enc(&out[i * 4], tmp);
224 	}
225 
226 	return (0);
227 }
228 
229 static int
230 aw_sid_sysctl(SYSCTL_HANDLER_ARGS)
231 {
232 	enum sid_keys key = arg2;
233 	u_char rootkey[16];
234 	char out[33];
235 
236 	if (key != AW_SID_ROOT_KEY)
237 		return (ENOENT);
238 
239 	if (aw_sid_get_rootkey(rootkey) != 0)
240 		return (ENOENT);
241 	snprintf(out, sizeof(out),
242 	  "%16D", rootkey, "");
243 
244 	return sysctl_handle_string(oidp, out, sizeof(out), req);
245 }
246 
247 static device_method_t aw_sid_methods[] = {
248 	/* Device interface */
249 	DEVMETHOD(device_probe,		aw_sid_probe),
250 	DEVMETHOD(device_attach,	aw_sid_attach),
251 
252 	DEVMETHOD_END
253 };
254 
255 static driver_t aw_sid_driver = {
256 	"aw_sid",
257 	aw_sid_methods,
258 	sizeof(struct aw_sid_softc),
259 };
260 
261 static devclass_t aw_sid_devclass;
262 
263 EARLY_DRIVER_MODULE(aw_sid, simplebus, aw_sid_driver, aw_sid_devclass, 0, 0,
264     BUS_PASS_RESOURCE + BUS_PASS_ORDER_FIRST);
265 MODULE_VERSION(aw_sid, 1);
266