1/*	$OpenBSD: exrtc.c,v 1.5 2022/10/17 19:09:46 kettenis Exp $	*/
2/*
3 * Copyright (c) 2017 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/time.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
29#include <dev/clock_subr.h>
30
31#define RTCCTRL		0x40
32#define RTCCTRL_RTCEN	(1 << 0)
33
34#define RTCSEC		0x70
35#define RTCMIN		0x74
36#define RTCHOUR		0x78
37#define RTCDAY		0x7c
38#define RTCMON		0x84
39#define RTCYEAR		0x88
40
41#define HREAD4(sc, reg)							\
42	(bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg)))
43#define HWRITE4(sc, reg, val)						\
44	bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, (reg), (val))
45
46struct exrtc_softc {
47	struct device	sc_dev;
48	bus_space_tag_t		sc_iot;
49	bus_space_handle_t	sc_ioh;
50	struct todr_chip_handle sc_todr;
51};
52
53int	exrtc_match(struct device *, void *, void *);
54void	exrtc_attach(struct device *, struct device *, void *);
55
56const struct cfattach exrtc_ca = {
57	sizeof(struct exrtc_softc), exrtc_match, exrtc_attach
58};
59
60struct cfdriver exrtc_cd = {
61	NULL, "exrtc", DV_DULL
62};
63
64int	exrtc_gettime(todr_chip_handle_t, struct timeval *);
65int	exrtc_settime(todr_chip_handle_t, struct timeval *);
66
67int
68exrtc_match(struct device *parent, void *match, void *aux)
69{
70	struct fdt_attach_args *faa = aux;
71
72	return OF_is_compatible(faa->fa_node, "samsung,s3c6410-rtc");
73}
74
75void
76exrtc_attach(struct device *parent, struct device *self, void *aux)
77{
78	struct exrtc_softc *sc = (struct exrtc_softc *)self;
79	struct fdt_attach_args *faa = aux;
80
81	sc->sc_iot = faa->fa_iot;
82
83	if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
84	    faa->fa_reg[0].size, 0, &sc->sc_ioh))
85		panic("%s: bus_space_map failed!", __func__);
86
87	printf("\n");
88
89	sc->sc_todr.cookie = sc;
90	sc->sc_todr.todr_gettime = exrtc_gettime;
91	sc->sc_todr.todr_settime = exrtc_settime;
92	sc->sc_todr.todr_quality = 0;
93	todr_attach(&sc->sc_todr);
94}
95
96int
97exrtc_gettime(todr_chip_handle_t handle, struct timeval *tv)
98{
99	struct exrtc_softc *sc = handle->cookie;
100	struct clock_ymdhms dt;
101	int retried = 0;
102
103retry:
104	dt.dt_sec = FROMBCD(HREAD4(sc, RTCSEC));
105	dt.dt_min = FROMBCD(HREAD4(sc, RTCMIN));
106	dt.dt_hour = FROMBCD(HREAD4(sc, RTCHOUR));
107	dt.dt_day = FROMBCD(HREAD4(sc, RTCDAY));
108	dt.dt_mon = FROMBCD(HREAD4(sc, RTCMON));
109	dt.dt_year = FROMBCD(HREAD4(sc, RTCYEAR)) + 1900;
110
111	/* If the second counter rolled over, retry. */
112	if (dt.dt_sec > FROMBCD(HREAD4(sc, RTCSEC)) && !retried) {
113		retried = 1;
114		goto retry;
115	}
116
117	if (dt.dt_sec > 59 || dt.dt_min > 59 || dt.dt_hour > 23 ||
118	    dt.dt_day > 31 || dt.dt_day == 0 ||
119	    dt.dt_mon > 12 || dt.dt_mon == 0 ||
120	    dt.dt_year < POSIX_BASE_YEAR)
121		return 1;
122
123	tv->tv_sec = clock_ymdhms_to_secs(&dt);
124	tv->tv_usec = 0;
125	return 0;
126}
127
128int
129exrtc_settime(todr_chip_handle_t handle, struct timeval *tv)
130{
131	struct exrtc_softc *sc = handle->cookie;
132	struct clock_ymdhms dt;
133	uint32_t val;
134
135	clock_secs_to_ymdhms(tv->tv_sec, &dt);
136
137	HWRITE4(sc, RTCSEC, TOBCD(dt.dt_sec));
138	HWRITE4(sc, RTCMIN, TOBCD(dt.dt_min));
139	HWRITE4(sc, RTCHOUR, TOBCD(dt.dt_hour));
140	HWRITE4(sc, RTCDAY, TOBCD(dt.dt_day));
141	HWRITE4(sc, RTCMON, TOBCD(dt.dt_mon));
142	HWRITE4(sc, RTCYEAR, TOBCD(dt.dt_year - 1900));
143
144	val = HREAD4(sc, RTCCTRL);
145	HWRITE4(sc, RTCCTRL, val | RTCCTRL_RTCEN);
146
147	return 0;
148}
149