1 /*        $NetBSD: imxsnvs.c,v 1.2 2024/02/07 04:20:26 msaitoh Exp $  */
2 
3 /*
4  * Copyright (c) 2014 Ryo Shimizu
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
25  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * i.MX6,7 Secure Non-Volatile Storage
31  */
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: imxsnvs.c,v 1.2 2024/02/07 04:20:26 msaitoh Exp $");
34 
35 #include "locators.h"
36 #include <sys/bus.h>
37 #include <sys/device.h>
38 #include <sys/param.h>
39 #include <dev/clock_subr.h>
40 
41 #include <arm/imx/imxsnvsreg.h>
42 #include <arm/imx/imxsnvsvar.h>
43 
44 struct imxsnvs_softc {
45           device_t sc_dev;
46           bus_space_tag_t sc_iot;
47           bus_space_handle_t sc_ioh;
48           struct todr_chip_handle sc_todr;
49 };
50 
51 #define SNVS_READ(sc, reg)                                            \
52           bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, reg)
53 
54 #define SNVS_WRITE(sc, reg, val)                                      \
55           bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, reg, val)
56 
57 static int imxsnvs_rtc_enable(struct imxsnvs_softc *);
58 static int imxsnvs_rtc_disable(struct imxsnvs_softc *);
59 static int imxsnvs_gettime(todr_chip_handle_t, struct timeval *);
60 static int imxsnvs_settime(todr_chip_handle_t, struct timeval *);
61 
62 
63 CFATTACH_DECL_NEW(imxsnvs, sizeof(struct imxsnvs_softc),
64     imxsnvs_match, imxsnvs_attach, NULL, NULL);
65 
66 /* ARGSUSED */
67 int
imxsnvs_attach_common(device_t parent __unused,device_t self,bus_space_tag_t iot,paddr_t iobase,size_t size,int intr __unused,int flags __unused)68 imxsnvs_attach_common(device_t parent __unused, device_t self,
69                       bus_space_tag_t iot, paddr_t iobase, size_t size,
70                       int intr __unused, int flags __unused)
71 {
72           struct imxsnvs_softc *sc;
73           uint32_t v1, v2;
74 
75           sc = device_private(self);
76           sc->sc_dev = self;
77           sc->sc_iot = iot;
78 
79           aprint_naive("\n");
80           aprint_normal(": Secure Non-Volatile Storage\n");
81           if (bus_space_map(sc->sc_iot, iobase, size, 0,
82               &sc->sc_ioh)) {
83                     aprint_error_dev(self, "Cannot map registers\n");
84                     return 1;
85           }
86 
87           v1 = SNVS_READ(sc, SNVS_HPVIDR1);
88           v2 = SNVS_READ(sc, SNVS_HPVIDR2);
89           aprint_verbose_dev(self, "id=0x%llx, ver=%lld.%lld, ip_era=0x%llx, "
90               "intg_opt=0x%llx, eco_rev=0x%llx, config_opt=0x%llx\n",
91               __SHIFTOUT(v1, SNVS_HPVIDR1_IP_ID),
92               __SHIFTOUT(v1, SNVS_HPVIDR1_MAJOR_REV),
93               __SHIFTOUT(v1, SNVS_HPVIDR1_MINOR_REV),
94               __SHIFTOUT(v2, SNVS_HPVIDR2_IP_ERA),
95               __SHIFTOUT(v2, SNVS_HPVIDR2_INTG_OPT),
96               __SHIFTOUT(v2, SNVS_HPVIDR2_ECO_REV),
97               __SHIFTOUT(v2, SNVS_HPVIDR2_CONFIG_OPT));
98 
99           if (imxsnvs_rtc_enable(sc) != 0) {
100                     aprint_error_dev(self, "cannot enable RTC\n");
101                     return 1;
102           }
103 
104           sc->sc_todr.todr_gettime = imxsnvs_gettime;
105           sc->sc_todr.todr_settime = imxsnvs_settime;
106           sc->sc_todr.cookie = sc;
107           todr_attach(&sc->sc_todr);
108 
109           return 0;
110 }
111 
112 static int
imxsnvs_rtc_enable(struct imxsnvs_softc * sc)113 imxsnvs_rtc_enable(struct imxsnvs_softc *sc)
114 {
115           uint32_t v;
116           int timeout;
117 
118           /* enable SRTC */
119           v = SNVS_READ(sc, SNVS_LPCR);
120           SNVS_WRITE(sc, SNVS_LPCR, v | SNVS_LPCR_SRTC_ENV);
121           for (timeout = 10000; timeout > 0; timeout--) {
122                     if (SNVS_READ(sc, SNVS_LPCR) & SNVS_LPCR_SRTC_ENV)
123                               break;
124           }
125           if (timeout == 0)
126                     return ETIMEDOUT;
127 
128           return 0;
129 }
130 
131 static int
imxsnvs_rtc_disable(struct imxsnvs_softc * sc)132 imxsnvs_rtc_disable(struct imxsnvs_softc *sc)
133 {
134           uint32_t v;
135           int timeout;
136 
137           /* disable SRTC */
138           v = SNVS_READ(sc, SNVS_LPCR);
139           SNVS_WRITE(sc, SNVS_LPCR, v & ~SNVS_LPCR_SRTC_ENV);
140           for (timeout = 10000; timeout > 0; timeout--) {
141                     if (!(SNVS_READ(sc, SNVS_LPCR) & SNVS_LPCR_SRTC_ENV))
142                               break;
143           }
144           if (timeout == 0)
145                     return ETIMEDOUT;
146 
147           return 0;
148 }
149 
150 static int
imxsnvs_gettime(todr_chip_handle_t tch,struct timeval * tvp)151 imxsnvs_gettime(todr_chip_handle_t tch, struct timeval *tvp)
152 {
153           struct imxsnvs_softc *sc;
154           uint64_t c1, c2;
155 
156           sc = tch->cookie;
157 
158           c2 = ((uint64_t)SNVS_READ(sc, SNVS_LPSRTCMR) << 32) +
159               SNVS_READ(sc, SNVS_LPSRTCLR);
160           do {
161                     c1 = c2;
162                     c2 = ((uint64_t)SNVS_READ(sc, SNVS_LPSRTCMR) << 32) +
163                         SNVS_READ(sc, SNVS_LPSRTCLR);
164           } while (c1 != c2);
165 
166           tvp->tv_sec = c1 >> SVNS_COUNTER_SHIFT;
167           tvp->tv_usec = (c1 % SVNS_COUNTER_HZ) * 1000000 / SVNS_COUNTER_HZ;
168 
169           return 0;
170 }
171 
172 static int
imxsnvs_settime(todr_chip_handle_t tch,struct timeval * tvp)173 imxsnvs_settime(todr_chip_handle_t tch, struct timeval *tvp)
174 {
175           struct imxsnvs_softc *sc;
176           uint64_t c, h, l;
177           int rv;
178 
179           c = (uint64_t)tvp->tv_sec * SVNS_COUNTER_HZ +
180               (uint64_t)tvp->tv_usec * SVNS_COUNTER_HZ / 1000000;
181           h = __SHIFTIN((c >> 32) & SNVS_LPSRTCMR_SRTC, SNVS_LPSRTCMR_SRTC);
182           l = c & 0xffffffff;
183 
184           sc = tch->cookie;
185           if ((rv = imxsnvs_rtc_disable(sc)) != 0)
186                     return rv;
187 
188           SNVS_WRITE(sc, SNVS_LPSRTCMR, h);
189           SNVS_WRITE(sc, SNVS_LPSRTCLR, l);
190 
191           if ((rv = imxsnvs_rtc_enable(sc)) != 0)
192                     return rv;
193 
194           return 0;
195 }
196