xref: /openbsd/sys/dev/i2c/m41t8x.c (revision d89ec533)
1 /*	$OpenBSD: m41t8x.c,v 1.2 2020/10/23 20:55:15 patrick Exp $	*/
2 
3 /*
4  * Copyright (c) 2010 Miodrag Vallat.
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 /*
20  * M41T8x clock connected to an I2C bus
21  */
22 
23 #include <sys/param.h>
24 #include <sys/kernel.h>
25 #include <sys/systm.h>
26 #include <sys/device.h>
27 
28 #include <dev/clock_subr.h>
29 #include <dev/i2c/i2cvar.h>
30 #include <dev/ic/m41t8xreg.h>
31 
32 struct m41t8xrtc_softc {
33 	struct device		sc_dev;
34 	struct todr_chip_handle	sc_todr;
35 	i2c_tag_t		sc_tag;
36 	i2c_addr_t		sc_addr;
37 };
38 
39 int	m41t8xrtc_match(struct device *, void *, void *);
40 void	m41t8xrtc_attach(struct device *, struct device *, void *);
41 
42 const struct cfattach mfokrtc_ca = {
43 	sizeof(struct m41t8xrtc_softc),
44 	m41t8xrtc_match, m41t8xrtc_attach
45 };
46 
47 struct cfdriver mfokrtc_cd = {
48 	NULL, "mfokrtc", DV_DULL
49 };
50 
51 int	m41t8xrtc_gettime(struct todr_chip_handle *, struct timeval *);
52 int	m41t8xrtc_settime(struct todr_chip_handle *, struct timeval *);
53 
54 int
55 m41t8xrtc_match(struct device *parent, void *vcf, void *aux)
56 {
57 	struct i2c_attach_args *ia = (struct i2c_attach_args *)aux;
58 
59 	if (strcmp(ia->ia_name, "st,m41t83") == 0 ||
60 	    strcmp(ia->ia_name, "microcrystal,rv4162") == 0)
61 		return (1);
62 	return (0);
63 
64 }
65 
66 void
67 m41t8xrtc_attach(struct device *parent, struct device *self, void *aux)
68 {
69 	struct m41t8xrtc_softc *sc = (struct m41t8xrtc_softc *)self;
70 	struct i2c_attach_args *ia = (struct i2c_attach_args *)aux;
71 
72 	sc->sc_tag = ia->ia_tag;
73 	sc->sc_addr = ia->ia_addr;
74 
75 	sc->sc_todr.cookie = sc;
76 	sc->sc_todr.todr_gettime = m41t8xrtc_gettime;
77 	sc->sc_todr.todr_settime = m41t8xrtc_settime;
78 	todr_attach(&sc->sc_todr);
79 
80 	printf("\n");
81 }
82 
83 int
84 m41t8xrtc_gettime(struct todr_chip_handle *handle, struct timeval *tv)
85 {
86 	struct clock_ymdhms dt;
87 	struct m41t8xrtc_softc *sc = handle->cookie;
88 	uint8_t regno, data[M41T8X_TOD_LENGTH];
89 	int s;
90 
91 	iic_acquire_bus(sc->sc_tag, 0);
92 	s = splclock();
93 	for (regno = M41T8X_TOD_START;
94 	    regno < M41T8X_TOD_START + M41T8X_TOD_LENGTH; regno++)
95 		iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr,
96 		    &regno, sizeof regno, data + regno - M41T8X_TOD_START,
97 		    sizeof data[0], 0);
98 	splx(s);
99 	iic_release_bus(sc->sc_tag, 0);
100 
101 	dt.dt_sec = FROMBCD(data[M41T8X_SEC] & ~M41T8X_STOP);
102 	dt.dt_min = FROMBCD(data[M41T8X_MIN]);
103 	dt.dt_hour = FROMBCD(data[M41T8X_HR] & ~(M41T8X_CEB | M41T8X_CB));
104 	dt.dt_day = FROMBCD(data[M41T8X_DAY]);
105 	dt.dt_mon = FROMBCD(data[M41T8X_MON]);
106 	dt.dt_year = FROMBCD(data[M41T8X_YEAR]) + 2000;
107 	if (data[M41T8X_HR] & M41T8X_CB)
108 		dt.dt_year += 100;
109 
110 	tv->tv_sec = clock_ymdhms_to_secs(&dt);
111 	tv->tv_usec = 0;
112 	return 0;
113 }
114 
115 int
116 m41t8xrtc_settime(struct todr_chip_handle *handle, struct timeval *tv)
117 {
118 	struct clock_ymdhms dt;
119 	struct m41t8xrtc_softc *sc = handle->cookie;
120 	uint8_t regno, data[M41T8X_TOD_LENGTH];
121 	int s;
122 
123 	clock_secs_to_ymdhms(tv->tv_sec, &dt);
124 
125 	iic_acquire_bus(sc->sc_tag, 0);
126 	s = splclock();
127 	/* read current state */
128 	for (regno = M41T8X_TOD_START;
129 	    regno < M41T8X_TOD_START + M41T8X_TOD_LENGTH; regno++)
130 		iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr,
131 		    &regno, sizeof regno, data + regno - M41T8X_TOD_START,
132 		    sizeof data[0], 0);
133 	/* compute new state */
134 	data[M41T8X_HSEC] = 0;
135 	data[M41T8X_SEC] = TOBCD(dt.dt_sec);
136 	data[M41T8X_MIN] = TOBCD(dt.dt_min);
137 	data[M41T8X_HR] &= M41T8X_CEB;
138 	if (dt.dt_year >= 2100)
139 		data[M41T8X_HR] |= M41T8X_CB;
140 	data[M41T8X_HR] |= TOBCD(dt.dt_hour);
141 	data[M41T8X_DOW] &= ~M41T8X_DOW_MASK;
142 	data[M41T8X_DOW] |= TOBCD(dt.dt_wday + 1);
143 	data[M41T8X_DAY] = TOBCD(dt.dt_day);
144 	data[M41T8X_MON] = TOBCD(dt.dt_mon);
145 	data[M41T8X_YEAR] = TOBCD(dt.dt_year % 100);
146 	/* write new state */
147 	for (regno = M41T8X_TOD_START;
148 	    regno < M41T8X_TOD_START + M41T8X_TOD_LENGTH; regno++)
149 		iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr,
150 		    &regno, sizeof regno, data + regno, sizeof data[0], 0);
151 	splx(s);
152 	iic_release_bus(sc->sc_tag, 0);
153 
154 	return 0;
155 }
156