1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2006 Sam Leffler. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 /*
29 * Dallas Semiconductor DS1672 RTC sitting on the I2C bus.
30 */
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/clock.h>
36 #include <sys/time.h>
37 #include <sys/bus.h>
38 #include <sys/resource.h>
39 #include <sys/rman.h>
40
41 #include <dev/iicbus/iiconf.h>
42
43 #include "iicbus_if.h"
44 #include "clock_if.h"
45
46 #define IIC_M_WR 0 /* write operation */
47
48 #define DS1672_ADDR 0xd0 /* slave address */
49
50 #define DS1672_COUNTER 0 /* counter (bytes 0-3) */
51 #define DS1672_CTRL 4 /* control (1 byte) */
52 #define DS1672_TRICKLE 5 /* trickle charger (1 byte) */
53
54 #define DS1672_CTRL_EOSC (1 << 7) /* Stop/start flag. */
55
56 #define MAX_IIC_DATA_SIZE 4
57
58 struct ds1672_softc {
59 device_t sc_dev;
60 };
61
62 static int
ds1672_probe(device_t dev)63 ds1672_probe(device_t dev)
64 {
65 /* XXX really probe? */
66 device_set_desc(dev, "Dallas Semiconductor DS1672 RTC");
67 return (BUS_PROBE_NOWILDCARD);
68 }
69
70 static int
ds1672_read(device_t dev,uint8_t addr,uint8_t * data,uint8_t size)71 ds1672_read(device_t dev, uint8_t addr, uint8_t *data, uint8_t size)
72 {
73 struct iic_msg msgs[2] = {
74 { DS1672_ADDR, IIC_M_WR, 1, &addr },
75 { DS1672_ADDR, IIC_M_RD, size, data }
76 };
77
78 return (iicbus_transfer(dev, msgs, 2));
79 }
80
81 static int
ds1672_write(device_t dev,uint8_t addr,uint8_t * data,uint8_t size)82 ds1672_write(device_t dev, uint8_t addr, uint8_t *data, uint8_t size)
83 {
84 uint8_t buffer[MAX_IIC_DATA_SIZE + 1];
85 struct iic_msg msgs[1] = {
86 { DS1672_ADDR, IIC_M_WR, size + 1, buffer },
87 };
88
89 if (size > MAX_IIC_DATA_SIZE)
90 return (ENOMEM);
91 /* NB: register pointer precedes actual data */
92 buffer[0] = addr;
93 memcpy(buffer + 1, data, size);
94 return (iicbus_transfer(dev, msgs, 1));
95 }
96
97 static int
ds1672_init(device_t dev)98 ds1672_init(device_t dev)
99 {
100 uint8_t ctrl;
101 int error;
102
103 error = ds1672_read(dev, DS1672_CTRL, &ctrl, 1);
104 if (error)
105 return (error);
106
107 /*
108 * Check if oscialltor is not runned.
109 */
110 if (ctrl & DS1672_CTRL_EOSC) {
111 device_printf(dev, "RTC oscillator was stopped. Check system"
112 " time and RTC battery.\n");
113 ctrl &= ~DS1672_CTRL_EOSC; /* Start oscillator. */
114 error = ds1672_write(dev, DS1672_CTRL, &ctrl, 1);
115 }
116 return (error);
117 }
118
119 static int
ds1672_detach(device_t dev)120 ds1672_detach(device_t dev)
121 {
122
123 clock_unregister(dev);
124 return (0);
125 }
126
127 static int
ds1672_attach(device_t dev)128 ds1672_attach(device_t dev)
129 {
130 struct ds1672_softc *sc = device_get_softc(dev);
131 int error;
132
133 sc->sc_dev = dev;
134 error = ds1672_init(dev);
135 if (error)
136 return (error);
137 clock_register(dev, 1000);
138 return (0);
139 }
140
141 static int
ds1672_gettime(device_t dev,struct timespec * ts)142 ds1672_gettime(device_t dev, struct timespec *ts)
143 {
144 uint8_t secs[4];
145 int error;
146
147 error = ds1672_read(dev, DS1672_COUNTER, secs, 4);
148 if (error == 0) {
149 /* counter has seconds since epoch */
150 ts->tv_sec = (secs[3] << 24) | (secs[2] << 16)
151 | (secs[1] << 8) | (secs[0] << 0);
152 ts->tv_nsec = 0;
153 }
154 clock_dbgprint_ts(dev, CLOCK_DBG_READ, ts);
155 return (error);
156 }
157
158 static int
ds1672_settime(device_t dev,struct timespec * ts)159 ds1672_settime(device_t dev, struct timespec *ts)
160 {
161 uint8_t data[4];
162
163 data[0] = (ts->tv_sec >> 0) & 0xff;
164 data[1] = (ts->tv_sec >> 8) & 0xff;
165 data[2] = (ts->tv_sec >> 16) & 0xff;
166 data[3] = (ts->tv_sec >> 24) & 0xff;
167
168 ts->tv_nsec = 0;
169 clock_dbgprint_ts(dev, CLOCK_DBG_WRITE, ts);
170 return (ds1672_write(dev, DS1672_COUNTER, data, 4));
171 }
172
173 static device_method_t ds1672_methods[] = {
174 DEVMETHOD(device_probe, ds1672_probe),
175 DEVMETHOD(device_attach, ds1672_attach),
176 DEVMETHOD(device_detach, ds1672_detach),
177
178 DEVMETHOD(clock_gettime, ds1672_gettime),
179 DEVMETHOD(clock_settime, ds1672_settime),
180
181 DEVMETHOD_END
182 };
183
184 static driver_t ds1672_driver = {
185 "ds1672_rtc",
186 ds1672_methods,
187 sizeof(struct ds1672_softc),
188 };
189
190 DRIVER_MODULE(ds1672, iicbus, ds1672_driver, 0, 0);
191 MODULE_VERSION(ds1672, 1);
192 MODULE_DEPEND(ds1672, iicbus, 1, 1, 1);
193