xref: /freebsd/sys/arm/allwinner/aw_rtc.c (revision 342af4d5efec74bb4bc11261fdd9991c53616f54)
1 /*-
2  * Copyright (c) 2016 Vladimir Belian <fate10@gmail.com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/bus.h>
32 #include <sys/time.h>
33 #include <sys/rman.h>
34 #include <sys/clock.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 #include <sys/resource.h>
39 
40 #include <machine/bus.h>
41 #include <machine/resource.h>
42 
43 #include <dev/ofw/ofw_bus.h>
44 #include <dev/ofw/ofw_bus_subr.h>
45 
46 #include <arm/allwinner/allwinner_machdep.h>
47 
48 #include "clock_if.h"
49 
50 #define	LOSC_CTRL_REG			0x00
51 #define	RTC_DATE_REG			0x04
52 #define	RTC_TIME_REG			0x08
53 
54 #define	TIME_MASK			0x001f3f3f
55 
56 #define	LOSC_OSC_SRC			0x00000001
57 #define	LOSC_GSM			0x00000008
58 #define	LOSC_AUTO_SW_EN			0x00004000
59 #define	LOSC_MAGIC			0x16aa0000
60 #define	LOSC_BUSY_MASK			0x00000380
61 
62 #define	IS_SUN7I 			(allwinner_soc_family() == ALLWINNERSOC_SUN7I)
63 
64 #define	YEAR_MIN			(IS_SUN7I ? 1970 : 2010)
65 #define	YEAR_MAX			(IS_SUN7I ? 2100 : 2073)
66 #define	YEAR_OFFSET			(IS_SUN7I ? 1900 : 2010)
67 #define	YEAR_MASK			(IS_SUN7I ? 0xff : 0x3f)
68 #define	LEAP_BIT			(IS_SUN7I ? 24 : 22)
69 
70 #define	GET_SEC_VALUE(x)		((x)  & 0x0000003f)
71 #define	GET_MIN_VALUE(x)		(((x) & 0x00003f00) >> 8)
72 #define	GET_HOUR_VALUE(x)		(((x) & 0x001f0000) >> 16)
73 #define	GET_DAY_VALUE(x)		((x)  & 0x0000001f)
74 #define	GET_MON_VALUE(x)		(((x) & 0x00000f00) >> 8)
75 #define	GET_YEAR_VALUE(x)		(((x) >> 16) & YEAR_MASK)
76 
77 #define	SET_DAY_VALUE(x)		GET_DAY_VALUE(x)
78 #define	SET_MON_VALUE(x)		(((x) & 0x0000000f) << 8)
79 #define	SET_YEAR_VALUE(x)		(((x) & YEAR_MASK)  << 16)
80 #define	SET_LEAP_VALUE(x)		(((x) & 0x00000001) << LEAP_BIT)
81 #define	SET_SEC_VALUE(x)		GET_SEC_VALUE(x)
82 #define	SET_MIN_VALUE(x)		(((x) & 0x0000003f) << 8)
83 #define	SET_HOUR_VALUE(x)		(((x) & 0x0000001f) << 16)
84 
85 #define	HALF_OF_SEC_NS			500000000
86 #define	RTC_RES_US			1000000
87 #define	RTC_TIMEOUT			70
88 
89 #define	RTC_READ(sc, reg) 		bus_read_4((sc)->res, (reg))
90 #define	RTC_WRITE(sc, reg, val)		bus_write_4((sc)->res, (reg), (val))
91 
92 #define	IS_LEAP_YEAR(y) \
93 	(((y) % 400) == 0 || (((y) % 100) != 0 && ((y) % 4) == 0))
94 
95 
96 static struct ofw_compat_data compat_data[] = {
97 	{ "allwinner,sun4i-a10-rtc", true },
98 	{ "allwinner,sun7i-a20-rtc", true },
99 	{ NULL, false }
100 };
101 
102 struct aw_rtc_softc {
103 	struct resource			*res;
104 };
105 
106 static int aw_rtc_probe(device_t dev);
107 static int aw_rtc_attach(device_t dev);
108 static int aw_rtc_detach(device_t dev);
109 
110 static int aw_rtc_gettime(device_t dev, struct timespec *ts);
111 static int aw_rtc_settime(device_t dev, struct timespec *ts);
112 
113 static device_method_t aw_rtc_methods[] = {
114 	DEVMETHOD(device_probe,		aw_rtc_probe),
115 	DEVMETHOD(device_attach,	aw_rtc_attach),
116 	DEVMETHOD(device_detach,	aw_rtc_detach),
117 
118 	DEVMETHOD(clock_gettime,	aw_rtc_gettime),
119 	DEVMETHOD(clock_settime,	aw_rtc_settime),
120 
121 	DEVMETHOD_END
122 };
123 
124 static driver_t aw_rtc_driver = {
125 	"rtc",
126 	aw_rtc_methods,
127 	sizeof(struct aw_rtc_softc),
128 };
129 
130 static devclass_t aw_rtc_devclass;
131 
132 EARLY_DRIVER_MODULE(aw_rtc, simplebus, aw_rtc_driver, aw_rtc_devclass, 0, 0,
133     BUS_PASS_TIMER + BUS_PASS_ORDER_MIDDLE);
134 
135 
136 static int
137 aw_rtc_probe(device_t dev)
138 {
139 	if (!ofw_bus_status_okay(dev))
140 		return (ENXIO);
141 
142 	if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
143 		return (ENXIO);
144 
145 	device_set_desc(dev, "Allwinner RTC");
146 
147 	return (BUS_PROBE_DEFAULT);
148 }
149 
150 static int
151 aw_rtc_attach(device_t dev)
152 {
153 	struct aw_rtc_softc *sc  = device_get_softc(dev);
154 	uint32_t val;
155 	int rid = 0;
156 
157 	sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
158 	if (!sc->res) {
159 		device_printf(dev, "could not allocate resources\n");
160 		return (ENXIO);
161 	}
162 
163 	val = RTC_READ(sc, LOSC_CTRL_REG);
164 	val &= ~LOSC_AUTO_SW_EN;
165 	val |= LOSC_MAGIC | LOSC_GSM | LOSC_OSC_SRC;
166 	RTC_WRITE(sc, LOSC_CTRL_REG, val);
167 
168 	DELAY(100);
169 
170 	val = RTC_READ(sc, LOSC_CTRL_REG);
171 	if ((val & LOSC_OSC_SRC) == 0) {
172 		bus_release_resource(dev, SYS_RES_MEMORY, rid, sc->res);
173 		device_printf(dev, "set LOSC to external failed\n");
174 		return (ENXIO);
175 	}
176 
177 	clock_register(dev, RTC_RES_US);
178 
179 	return (0);
180 }
181 
182 static int
183 aw_rtc_detach(device_t dev)
184 {
185 	/* can't support detach, since there's no clock_unregister function */
186 	return (EBUSY);
187 }
188 
189 static int
190 aw_rtc_gettime(device_t dev, struct timespec *ts)
191 {
192 	struct aw_rtc_softc *sc  = device_get_softc(dev);
193 	struct clocktime ct;
194 	uint32_t rdate, rtime;
195 
196 	rdate = RTC_READ(sc, RTC_DATE_REG);
197 	rtime = RTC_READ(sc, RTC_TIME_REG);
198 
199 	if ((rtime & TIME_MASK) == 0)
200 		rdate = RTC_READ(sc, RTC_DATE_REG);
201 
202 	ct.sec = GET_SEC_VALUE(rtime);
203 	ct.min = GET_MIN_VALUE(rtime);
204 	ct.hour = GET_HOUR_VALUE(rtime);
205 	ct.day = GET_DAY_VALUE(rdate);
206 	ct.mon = GET_MON_VALUE(rdate);
207 	ct.year = GET_YEAR_VALUE(rdate) + YEAR_OFFSET;
208 	ct.dow = -1;
209 	/* RTC resolution is 1 sec */
210 	ct.nsec = 0;
211 
212 	return (clock_ct_to_ts(&ct, ts));
213 }
214 
215 static int
216 aw_rtc_settime(device_t dev, struct timespec *ts)
217 {
218 	struct aw_rtc_softc *sc  = device_get_softc(dev);
219 	struct clocktime ct;
220 	uint32_t clk, rdate, rtime;
221 
222 	/* RTC resolution is 1 sec */
223 	if (ts->tv_nsec >= HALF_OF_SEC_NS)
224 		ts->tv_sec++;
225 	ts->tv_nsec = 0;
226 
227 	clock_ts_to_ct(ts, &ct);
228 
229 	if ((ct.year < YEAR_MIN) || (ct.year > YEAR_MAX)) {
230 		device_printf(dev, "could not set time, year out of range\n");
231 		return (EINVAL);
232 	}
233 
234 	for (clk = 0; RTC_READ(sc, LOSC_CTRL_REG) & LOSC_BUSY_MASK; clk++) {
235 		if (clk > RTC_TIMEOUT) {
236 			device_printf(dev, "could not set time, RTC busy\n");
237 			return (EINVAL);
238 		}
239 		DELAY(1);
240 	}
241 	/* reset time register to avoid unexpected date increment */
242 	RTC_WRITE(sc, RTC_TIME_REG, 0);
243 
244 	rdate = SET_DAY_VALUE(ct.day) | SET_MON_VALUE(ct.mon) |
245 		SET_YEAR_VALUE(ct.year - YEAR_OFFSET) |
246 		SET_LEAP_VALUE(IS_LEAP_YEAR(ct.year));
247 
248 	rtime = SET_SEC_VALUE(ct.sec) | SET_MIN_VALUE(ct.min) |
249 		SET_HOUR_VALUE(ct.hour);
250 
251 	for (clk = 0; RTC_READ(sc, LOSC_CTRL_REG) & LOSC_BUSY_MASK; clk++) {
252 		if (clk > RTC_TIMEOUT) {
253 			device_printf(dev, "could not set date, RTC busy\n");
254 			return (EINVAL);
255 		}
256 		DELAY(1);
257 	}
258 	RTC_WRITE(sc, RTC_DATE_REG, rdate);
259 
260 	for (clk = 0; RTC_READ(sc, LOSC_CTRL_REG) & LOSC_BUSY_MASK; clk++) {
261 		if (clk > RTC_TIMEOUT) {
262 			device_printf(dev, "could not set time, RTC busy\n");
263 			return (EINVAL);
264 		}
265 		DELAY(1);
266 	}
267 	RTC_WRITE(sc, RTC_TIME_REG, rtime);
268 
269 	DELAY(RTC_TIMEOUT);
270 
271 	return (0);
272 }
273