xref: /freebsd/sys/dev/iicbus/rtc/pcf85063.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2021 Alstom Group.
5  * Copyright (c) 2021 Semihalf.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 #include "opt_platform.h"
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 #include <sys/clock.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/module.h>
38 
39 #include <dev/ofw/ofw_bus.h>
40 #include <dev/ofw/ofw_bus_subr.h>
41 
42 #include <dev/iicbus/iiconf.h>
43 #include <dev/iicbus/iicbus.h>
44 
45 #include "clock_if.h"
46 #include "iicbus_if.h"
47 
48 #define BIT(x)				(1 << (x))
49 
50 #define PCF85063_CTRL1_REG		0x0
51 #define PCF85063_TIME_REG		0x4
52 
53 #define PCF85063_CTRL1_TIME_FORMAT	BIT(1)
54 #define PCF85063_CTRL1_RTC_CLK_STOP	BIT(5)
55 #define PCF85063_TIME_REG_OSC_STOP	BIT(7)
56 
57 #define PCF85063_HALF_OF_SEC_NS		500000000
58 
59 struct pcf85063_time {
60 	uint8_t		sec;
61 	uint8_t		min;
62 	uint8_t		hour;
63 	uint8_t		day;
64 	uint8_t		dow;
65 	uint8_t		mon;
66 	uint8_t		year;
67 };
68 
69 static int pcf85063_attach(device_t dev);
70 static int pcf85063_detach(device_t dev);
71 static int pcf85063_probe(device_t dev);
72 
73 static int pcf85063_get_time(device_t dev, struct timespec *ts);
74 static int pcf85063_set_time(device_t dev, struct timespec *ts);
75 
76 static int pcf85063_check_status(device_t dev);
77 
78 static struct ofw_compat_data pcf85063_compat_data[] = {
79 	{ "nxp,pcf85063",		1},
80 	{ NULL,				0}
81 };
82 
83 static int
84 pcf85063_check_status(device_t dev)
85 {
86 	uint8_t flags;
87 	int error;
88 
89 	error = iicdev_readfrom(dev, PCF85063_TIME_REG, &flags, 1, IIC_WAIT);
90 	if (error != 0)
91 		return (error);
92 
93 	if (flags & PCF85063_TIME_REG_OSC_STOP) {
94 		device_printf(dev,
95 		    "Low voltage flag set, date is incorrect.\n");
96 		return (ENXIO);
97 	}
98 
99 	return (0);
100 }
101 
102 static int
103 pcf85063_attach(device_t dev)
104 {
105 
106 	clock_register_flags(dev, 1000000, 0);
107 	clock_schedule(dev, 1);
108 
109 	return (0);
110 }
111 
112 static int
113 pcf85063_detach(device_t dev)
114 {
115 
116 	clock_unregister(dev);
117 
118 	return (0);
119 }
120 
121 static int
122 pcf85063_get_time(device_t dev, struct timespec *ts)
123 {
124 	struct pcf85063_time data;
125 	struct bcd_clocktime bcd;
126 	uint8_t control_reg;
127 	int error;
128 
129 	error = pcf85063_check_status(dev);
130 	if (error != 0)
131 		return (error);
132 
133 	/* read hour format (12/24 hour mode) */
134 	error = iicdev_readfrom(dev, PCF85063_CTRL1_REG, &control_reg,
135 	    sizeof(uint8_t), IIC_WAIT);
136 	if (error != 0)
137 		return (error);
138 
139 	/* read current date and time */
140 	error = iicdev_readfrom(dev, PCF85063_TIME_REG, &data,
141 	    sizeof(struct pcf85063_time), IIC_WAIT);
142 	if (error != 0)
143 		return (error);
144 
145 	bcd.nsec = 0;
146 	bcd.sec = data.sec & 0x7F;
147 	bcd.min = data.min & 0x7F;
148 
149 	if (control_reg & PCF85063_CTRL1_TIME_FORMAT) {
150 		/* 12 hour mode */
151 		bcd.hour = data.hour & 0x1F;
152 		/* Check if hour is pm */
153 		bcd.ispm = data.hour & 0x20;
154 	} else {
155 		/* 24 hour mode */
156 		bcd.hour = data.hour & 0x3F;
157 		bcd.ispm = false;
158 	}
159 
160 	bcd.dow = (data.dow & 0x7) + 1;
161 	bcd.day = data.day & 0x3F;
162 	bcd.mon = data.mon & 0x1F;
163 	bcd.year = data.year;
164 
165 	clock_dbgprint_bcd(dev, CLOCK_DBG_READ, &bcd);
166 	error = clock_bcd_to_ts(&bcd, ts,
167 	    control_reg & PCF85063_CTRL1_TIME_FORMAT);
168 
169 	return (error);
170 }
171 
172 static int
173 pcf85063_set_time(device_t dev, struct timespec *ts)
174 {
175 	uint8_t time_reg, ctrl_reg;
176 	struct pcf85063_time data;
177 	struct bcd_clocktime bcd;
178 	int error;
179 
180 	error = iicdev_readfrom(dev, PCF85063_TIME_REG, &ctrl_reg,
181 	    sizeof(uint8_t), IIC_WAIT);
182 
183 	ts->tv_sec -= utc_offset();
184 	clock_ts_to_bcd(ts, &bcd, false);
185 	clock_dbgprint_bcd(dev, CLOCK_DBG_WRITE, &bcd);
186 
187 	data.sec = bcd.sec;
188 	data.min = bcd.min;
189 	data.hour = bcd.hour;
190 	data.dow = bcd.dow - 1;
191 	data.day = bcd.day;
192 	data.mon = bcd.mon;
193 	data.year = bcd.year;
194 
195 	if (ts->tv_nsec > PCF85063_HALF_OF_SEC_NS)
196 		data.sec++;
197 
198 	/* disable clock */
199 	error = iicdev_readfrom(dev, PCF85063_CTRL1_REG, &ctrl_reg,
200 	    sizeof(uint8_t), IIC_WAIT);
201 	if (error != 0)
202 		return (error);
203 
204 	ctrl_reg |= PCF85063_CTRL1_RTC_CLK_STOP;
205 	/* Explicitly set 24-hour mode. */
206 	ctrl_reg &= ~PCF85063_CTRL1_TIME_FORMAT;
207 
208 	error = iicdev_writeto(dev, PCF85063_CTRL1_REG, &ctrl_reg,
209 	    sizeof(uint8_t), IIC_WAIT);
210 	if (error != 0)
211 		return (error);
212 
213 	/* clock is disabled now, write time and date */
214 	error = iicdev_writeto(dev, PCF85063_TIME_REG, &data,
215 	    sizeof(struct pcf85063_time), IIC_WAIT);
216 	if (error != 0)
217 		return (error);
218 
219 	/* restart clock */
220 	ctrl_reg &= ~PCF85063_CTRL1_RTC_CLK_STOP;
221 	error = iicdev_writeto(dev, PCF85063_CTRL1_REG, &ctrl_reg,
222 	    sizeof(uint8_t), IIC_WAIT);
223 	if (error != 0)
224 		return (error);
225 
226 	/* reset low voltage flag */
227 	error = iicdev_readfrom(dev, PCF85063_TIME_REG, &time_reg,
228 	    sizeof(uint8_t), IIC_WAIT);
229 	if (error != 0)
230 		return (error);
231 
232 	time_reg &= ~PCF85063_TIME_REG_OSC_STOP;
233 
234 	error = iicdev_writeto(dev, PCF85063_TIME_REG, &time_reg,
235 	    sizeof(uint8_t), IIC_WAIT);
236 
237 	return (error);
238 }
239 
240 static int
241 pcf85063_probe(device_t dev)
242 {
243 
244 	if (!ofw_bus_status_okay(dev))
245 		return (ENXIO);
246 
247 	if (!ofw_bus_search_compatible(dev, pcf85063_compat_data)->ocd_data)
248 		return (ENXIO);
249 
250 	device_set_desc(dev, "NXP pcf85063 Real Time Clock");
251 
252 	return (BUS_PROBE_GENERIC);
253 }
254 
255 static device_method_t pcf85063_methods [] = {
256 	DEVMETHOD(device_attach, pcf85063_attach),
257 	DEVMETHOD(device_detach, pcf85063_detach),
258 	DEVMETHOD(device_probe, pcf85063_probe),
259 
260 	DEVMETHOD(clock_gettime, pcf85063_get_time),
261 	DEVMETHOD(clock_settime, pcf85063_set_time),
262 
263 	DEVMETHOD_END
264 };
265 
266 static driver_t pcf85063_driver = {
267 	"pcf85063",
268 	pcf85063_methods,
269 	0
270 };
271 
272 DRIVER_MODULE(pcf85063, iicbus, pcf85063_driver, NULL, NULL);
273 IICBUS_FDT_PNP_INFO(pcf85063_compat_data);
274