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1/* $OpenBSD: imxrtc.c,v 1.3 2022/10/17 19:09:46 kettenis Exp $ */
2/*
3 * Copyright (c) 2018 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
22#include <machine/intr.h>
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#include <dev/clock_subr.h>
31
32/* Registers. */
33#define LPCR 0x38
34#define LPCR_SRTC_ENV (1 << 0)
35#define LPSR 0x4c
36#define LPSRTCMR 0x50
37#define LPSRTCLR 0x54
38
39#define HREAD4(sc, reg) \
40 (regmap_read_4((sc)->sc_rm, (reg)))
41#define HWRITE4(sc, reg, val) \
42 regmap_write_4((sc)->sc_rm, (reg), (val))
43
44struct imxrtc_softc {
45 struct device sc_dev;
46 struct regmap *sc_rm;
47
48 struct todr_chip_handle sc_todr;
49};
50
51int imxrtc_match(struct device *, void *, void *);
52void imxrtc_attach(struct device *, struct device *, void *);
53
54const struct cfattach imxrtc_ca = {
55 sizeof (struct imxrtc_softc), imxrtc_match, imxrtc_attach
56};
57
58struct cfdriver imxrtc_cd = {
59 NULL, "imxrtc", DV_DULL
60};
61
62int imxrtc_gettime(struct todr_chip_handle *, struct timeval *);
63int imxrtc_settime(struct todr_chip_handle *, struct timeval *);
64
65int
66imxrtc_match(struct device *parent, void *match, void *aux)
67{
68 struct fdt_attach_args *faa = aux;
69
70 return OF_is_compatible(faa->fa_node, "fsl,sec-v4.0-mon-rtc-lp");
71}
72
73void
74imxrtc_attach(struct device *parent, struct device *self, void *aux)
75{
76 struct imxrtc_softc *sc = (struct imxrtc_softc *)self;
77 struct fdt_attach_args *faa = aux;
78 uint32_t regmap;
79
80 regmap = OF_getpropint(faa->fa_node, "regmap", 0);
81 sc->sc_rm = regmap_byphandle(regmap);
82 if (sc->sc_rm == NULL) {
83 printf(": no registers\n");
84 return;
85 }
86
87 printf("\n");
88
89 sc->sc_todr.cookie = sc;
90 sc->sc_todr.todr_gettime = imxrtc_gettime;
91 sc->sc_todr.todr_settime = imxrtc_settime;
92 sc->sc_todr.todr_quality = 0;
93 todr_attach(&sc->sc_todr);
94}
95
96int
97imxrtc_gettime(struct todr_chip_handle *handle, struct timeval *tv)
98{
99 struct imxrtc_softc *sc = handle->cookie;
100 uint64_t mr, lr, srtc, srtc2;
101 uint32_t cr;
102 int retries;
103 int s;
104
105 cr = HREAD4(sc, LPCR);
106 if ((cr & LPCR_SRTC_ENV) == 0)
107 return EINVAL;
108
109 /*
110 * Read counters until we read back the same values twice.
111 * This shouldn't take more than two attempts; throw in an
112 * extra round just in case.
113 */
114 s = splhigh();
115 mr = HREAD4(sc, LPSRTCMR);
116 lr = HREAD4(sc, LPSRTCLR);
117 srtc = (mr << 32) | lr;
118 for (retries = 3; retries > 0; retries--) {
119 mr = HREAD4(sc, LPSRTCMR);
120 lr = HREAD4(sc, LPSRTCLR);
121 srtc2 = (mr << 32) | lr;
122 if (srtc == srtc2)
123 break;
124 srtc = srtc2;
125 }
126 splx(s);
127 if (retries == 0)
128 return EIO;
129
130 tv->tv_sec = srtc / 32768;
131 tv->tv_usec = ((srtc % 32768) * 1000000U) / 32768U;
132 return 0;
133}
134
135int
136imxrtc_settime(struct todr_chip_handle *handle, struct timeval *tv)
137{
138 struct imxrtc_softc *sc = handle->cookie;
139 uint64_t srtc;
140 uint32_t cr;
141 int timeout;
142
143 /* Disable RTC. */
144 cr = HREAD4(sc, LPCR);
145 cr &= ~LPCR_SRTC_ENV;
146 HWRITE4(sc, LPCR, cr);
147 for (timeout = 1000000; timeout > 0; timeout--) {
148 if ((HREAD4(sc, LPCR) & LPCR_SRTC_ENV) == 0)
149 break;
150 }
151
152 srtc = tv->tv_sec * 32768 + (tv->tv_usec * 32768U / 1000000U);
153 HWRITE4(sc, LPSRTCMR, srtc >> 32);
154 HWRITE4(sc, LPSRTCLR, srtc & 0xffffffff);
155
156 /* Enable RTC. */
157 cr |= LPCR_SRTC_ENV;
158 HWRITE4(sc, LPCR, cr);
159 for (timeout = 1000000; timeout > 0; timeout--) {
160 if (HREAD4(sc, LPCR) & LPCR_SRTC_ENV)
161 break;
162 }
163
164 return 0;
165}