1/*-
2 * Copyright (c) 2006 Sam Leffler.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#include <sys/cdefs.h>
26__FBSDID("$FreeBSD$");
27/*
28 * Dallas Semiconductor DS1672 RTC sitting on the I2C bus.
29 */
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/module.h>
34#include <sys/clock.h>
35#include <sys/time.h>
36#include <sys/bus.h>
37#include <sys/resource.h>
38#include <sys/rman.h>
39
40#include <dev/iicbus/iiconf.h>
41
42#include "iicbus_if.h"
43#include "clock_if.h"
44
45#define	IIC_M_WR	0	/* write operation */
46
47#define	DS1672_ADDR	0xd0	/* slave address */
48
49#define	DS1672_COUNTER	0	/* counter (bytes 0-3) */
50#define	DS1672_CTRL	4	/* control (1 byte) */
51#define	DS1672_TRICKLE	5	/* trickle charger (1 byte) */
52
53#define	DS1672_CTRL_EOSC	(1 << 7)	/* Stop/start flag. */
54
55#define NANOSEC		1000000000
56
57#define	MAX_IIC_DATA_SIZE	4
58
59struct ds1672_softc {
60	device_t		sc_dev;
61};
62
63static int
64ds1672_probe(device_t dev)
65{
66	/* XXX really probe? */
67	device_set_desc(dev, "Dallas Semiconductor DS1672 RTC");
68	return (BUS_PROBE_NOWILDCARD);
69}
70
71static int
72ds1672_read(device_t dev, uint8_t addr, uint8_t *data, uint8_t size)
73{
74	struct iic_msg msgs[2] = {
75	     { DS1672_ADDR, IIC_M_WR, 1, &addr },
76	     { DS1672_ADDR, IIC_M_RD, size, data }
77	};
78
79	return (iicbus_transfer(dev, msgs, 2));
80}
81
82static int
83ds1672_write(device_t dev, uint8_t addr, uint8_t *data, uint8_t size)
84{
85	uint8_t buffer[MAX_IIC_DATA_SIZE + 1];
86	struct iic_msg msgs[1] = {
87	     { DS1672_ADDR, IIC_M_WR, size + 1, buffer },
88	};
89
90	if (size > MAX_IIC_DATA_SIZE)
91		return (ENOMEM);
92	/* NB: register pointer precedes actual data */
93	buffer[0] = addr;
94	memcpy(buffer + 1, data, size);
95	return (iicbus_transfer(dev, msgs, 1));
96}
97
98static int
99ds1672_init(device_t dev)
100{
101	uint8_t ctrl;
102	int error;
103
104	error = ds1672_read(dev, DS1672_CTRL, &ctrl, 1);
105	if (error)
106		return (error);
107
108	/*
109	 * Check if oscialltor is not runned.
110	 */
111	if (ctrl & DS1672_CTRL_EOSC) {
112		device_printf(dev, "RTC oscillator was stopped. Check system"
113		    " time and RTC battery.\n");
114		ctrl &= ~DS1672_CTRL_EOSC;	/* Start oscillator. */
115		error = ds1672_write(dev, DS1672_CTRL, &ctrl, 1);
116	}
117	return (error);
118}
119
120static int
121ds1672_attach(device_t dev)
122{
123	struct ds1672_softc *sc = device_get_softc(dev);
124	int error;
125
126	sc->sc_dev = dev;
127	error = ds1672_init(dev);
128	if (error)
129		return (error);
130	clock_register(dev, 1000);
131	return (0);
132}
133
134static int
135ds1672_gettime(device_t dev, struct timespec *ts)
136{
137	uint8_t secs[4];
138	int error;
139
140	error = ds1672_read(dev, DS1672_COUNTER, secs, 4);
141	if (error == 0) {
142		/* counter has seconds since epoch */
143		ts->tv_sec = (secs[3] << 24) | (secs[2] << 16)
144			   | (secs[1] <<  8) | (secs[0] <<  0);
145		ts->tv_nsec = NANOSEC / 2;
146	}
147	return (error);
148}
149
150static int
151ds1672_settime(device_t dev, struct timespec *ts)
152{
153	uint8_t data[4];
154
155	data[0] = (ts->tv_sec >> 0) & 0xff;
156	data[1] = (ts->tv_sec >> 8) & 0xff;
157	data[2] = (ts->tv_sec >> 16) & 0xff;
158	data[3] = (ts->tv_sec >> 24) & 0xff;
159
160	return (ds1672_write(dev, DS1672_COUNTER, data, 4));
161}
162
163static device_method_t ds1672_methods[] = {
164	DEVMETHOD(device_probe,		ds1672_probe),
165	DEVMETHOD(device_attach,	ds1672_attach),
166
167	DEVMETHOD(clock_gettime,	ds1672_gettime),
168	DEVMETHOD(clock_settime,	ds1672_settime),
169
170	DEVMETHOD_END
171};
172
173static driver_t ds1672_driver = {
174	"ds1672_rtc",
175	ds1672_methods,
176	sizeof(struct ds1672_softc),
177};
178static devclass_t ds1672_devclass;
179
180DRIVER_MODULE(ds1672, iicbus, ds1672_driver, ds1672_devclass, 0, 0);
181MODULE_VERSION(ds1672, 1);
182MODULE_DEPEND(ds1672, iicbus, 1, 1, 1);
183