1 /* $OpenBSD: amlsm.c,v 1.3 2021/10/24 17:52:26 mpi Exp $ */
2 /*
3 * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #include <sys/param.h>
19 #include <sys/systm.h>
20 #include <sys/device.h>
21 #include <sys/timeout.h>
22
23 #include <machine/bus.h>
24 #include <machine/fdt.h>
25
26 #include <dev/ofw/openfirm.h>
27 #include <dev/ofw/fdt.h>
28 #include <dev/ofw/ofw_misc.h>
29
30 extern register_t smc_call(register_t, register_t, register_t, register_t);
31
32 /* Calls */
33 #define AML_SM_GET_SHARE_MEM_INPUT_BASE 0x82000020
34 #define AML_SM_GET_SHARE_MEM_OUTPUT_BASE 0x82000021
35 #define AML_SM_EFUSE_READ 0x82000030
36 #define AML_SM_EFUSE_USER_MAX 0x82000033
37 #define AML_SM_JTAG_ON 0x82000040
38 #define AML_SM_JTAG_OFF 0x82000041
39 #define AML_SM_GET_CHIP_ID 0x82000044
40
41 struct aml_cpu_info {
42 uint32_t version;
43 uint32_t chip_id[4];
44 };
45
46 struct amlsm_softc {
47 struct device sc_dev;
48 bus_space_tag_t sc_iot;
49 bus_space_handle_t sc_in_ioh;
50 bus_space_handle_t sc_out_ioh;
51 };
52
53 int amlsm_match(struct device *, void *, void *);
54 void amlsm_attach(struct device *, struct device *, void *);
55
56 const struct cfattach amlsm_ca = {
57 sizeof (struct amlsm_softc), amlsm_match, amlsm_attach
58 };
59
60 struct cfdriver amlsm_cd = {
61 NULL, "amlsm", DV_DULL
62 };
63
64 int
amlsm_match(struct device * parent,void * match,void * aux)65 amlsm_match(struct device *parent, void *match, void *aux)
66 {
67 struct fdt_attach_args *faa = aux;
68
69 return OF_is_compatible(faa->fa_node, "amlogic,meson-gxbb-sm");
70 }
71
72 void
amlsm_attach(struct device * parent,struct device * self,void * aux)73 amlsm_attach(struct device *parent, struct device *self, void *aux)
74 {
75 struct amlsm_softc *sc = (struct amlsm_softc *)self;
76 struct fdt_attach_args *faa = aux;
77 struct aml_cpu_info *info;
78 bus_addr_t addr;
79 int32_t ret;
80 int i;
81
82 sc->sc_iot = faa->fa_iot;
83
84 addr = smc_call(AML_SM_GET_SHARE_MEM_INPUT_BASE, 0, 0, 0);
85 if (addr == (bus_addr_t)-1 ||
86 bus_space_map(sc->sc_iot, addr, PAGE_SIZE,
87 BUS_SPACE_MAP_CACHEABLE, &sc->sc_in_ioh)) {
88 printf(": can't map shared memory\n");
89 return;
90 }
91 addr = smc_call(AML_SM_GET_SHARE_MEM_OUTPUT_BASE, 0, 0, 0);
92 if (addr == (bus_addr_t)-1 ||
93 bus_space_map(sc->sc_iot, addr, PAGE_SIZE,
94 BUS_SPACE_MAP_CACHEABLE, &sc->sc_out_ioh)) {
95 bus_space_unmap(sc->sc_iot, sc->sc_in_ioh, PAGE_SIZE);
96 printf(": can't map shared memory\n");
97 return;
98 }
99
100 /*
101 * Version 2 gives us a 16-byte chip ID. If that fails, fall
102 * back on version 0/1 which gives us a 12-byte chipt ID.
103 */
104 info = bus_space_vaddr(sc->sc_iot, sc->sc_out_ioh);
105 memset(info, 0, sizeof(struct aml_cpu_info));
106 ret = smc_call(AML_SM_GET_CHIP_ID, 2, 0, 0);
107 if (ret == -1)
108 ret = smc_call(AML_SM_GET_CHIP_ID, 0, 0, 0);
109
110 printf(": ver %u\n", info->version);
111
112 if (ret != -1) {
113 for (i = 0; i < nitems(info->chip_id); i++)
114 enqueue_randomness(info->chip_id[i]);
115 }
116 }
117