aw_rtc.c revision 309754 
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: stable/11/sys/arm/allwinner/aw_rtc.c 309754 2016-12-09 19:40:33Z manu $");
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/aw_machdep.h>
47
48#include "clock_if.h"
49
50#define	LOSC_CTRL_REG			0x00
51#define	A10_RTC_DATE_REG		0x04
52#define	A10_RTC_TIME_REG		0x08
53#define	A31_LOSC_AUTO_SWT_STA		0x04
54#define	A31_RTC_DATE_REG		0x10
55#define	A31_RTC_TIME_REG		0x14
56
57#define	TIME_MASK			0x001f3f3f
58
59#define	LOSC_OSC_SRC			(1 << 0)
60#define	LOSC_GSM			(1 << 3)
61#define	LOSC_AUTO_SW_EN			(1 << 14)
62#define	LOSC_MAGIC			0x16aa0000
63#define	LOSC_BUSY_MASK			0x00000380
64
65#define	IS_SUN7I			(sc->type == A20_RTC)
66
67#define	YEAR_MIN			(IS_SUN7I ? 1970 : 2010)
68#define	YEAR_MAX			(IS_SUN7I ? 2100 : 2073)
69#define	YEAR_OFFSET			(IS_SUN7I ? 1900 : 2010)
70#define	YEAR_MASK			(IS_SUN7I ? 0xff : 0x3f)
71#define	LEAP_BIT			(IS_SUN7I ? 24 : 22)
72
73#define	GET_SEC_VALUE(x)		((x)  & 0x0000003f)
74#define	GET_MIN_VALUE(x)		(((x) & 0x00003f00) >> 8)
75#define	GET_HOUR_VALUE(x)		(((x) & 0x001f0000) >> 16)
76#define	GET_DAY_VALUE(x)		((x)  & 0x0000001f)
77#define	GET_MON_VALUE(x)		(((x) & 0x00000f00) >> 8)
78#define	GET_YEAR_VALUE(x)		(((x) >> 16) & YEAR_MASK)
79
80#define	SET_DAY_VALUE(x)		GET_DAY_VALUE(x)
81#define	SET_MON_VALUE(x)		(((x) & 0x0000000f) << 8)
82#define	SET_YEAR_VALUE(x)		(((x) & YEAR_MASK)  << 16)
83#define	SET_LEAP_VALUE(x)		(((x) & 0x00000001) << LEAP_BIT)
84#define	SET_SEC_VALUE(x)		GET_SEC_VALUE(x)
85#define	SET_MIN_VALUE(x)		(((x) & 0x0000003f) << 8)
86#define	SET_HOUR_VALUE(x)		(((x) & 0x0000001f) << 16)
87
88#define	HALF_OF_SEC_NS			500000000
89#define	RTC_RES_US			1000000
90#define	RTC_TIMEOUT			70
91
92#define	RTC_READ(sc, reg) 		bus_read_4((sc)->res, (reg))
93#define	RTC_WRITE(sc, reg, val)		bus_write_4((sc)->res, (reg), (val))
94
95#define	IS_LEAP_YEAR(y) \
96	(((y) % 400) == 0 || (((y) % 100) != 0 && ((y) % 4) == 0))
97
98#define	A10_RTC	1
99#define	A20_RTC	2
100#define	A31_RTC	3
101
102static struct ofw_compat_data compat_data[] = {
103	{ "allwinner,sun4i-a10-rtc", A10_RTC },
104	{ "allwinner,sun7i-a20-rtc", A20_RTC },
105	{ "allwinner,sun6i-a31-rtc", A31_RTC },
106	{ NULL, 0 }
107};
108
109struct aw_rtc_softc {
110	struct resource		*res;
111	int			type;
112	bus_size_t		rtc_date;
113	bus_size_t		rtc_time;
114};
115
116static int aw_rtc_probe(device_t dev);
117static int aw_rtc_attach(device_t dev);
118static int aw_rtc_detach(device_t dev);
119
120static int aw_rtc_gettime(device_t dev, struct timespec *ts);
121static int aw_rtc_settime(device_t dev, struct timespec *ts);
122
123static device_method_t aw_rtc_methods[] = {
124	DEVMETHOD(device_probe,		aw_rtc_probe),
125	DEVMETHOD(device_attach,	aw_rtc_attach),
126	DEVMETHOD(device_detach,	aw_rtc_detach),
127
128	DEVMETHOD(clock_gettime,	aw_rtc_gettime),
129	DEVMETHOD(clock_settime,	aw_rtc_settime),
130
131	DEVMETHOD_END
132};
133
134static driver_t aw_rtc_driver = {
135	"rtc",
136	aw_rtc_methods,
137	sizeof(struct aw_rtc_softc),
138};
139
140static devclass_t aw_rtc_devclass;
141
142EARLY_DRIVER_MODULE(aw_rtc, simplebus, aw_rtc_driver, aw_rtc_devclass, 0, 0,
143    BUS_PASS_TIMER + BUS_PASS_ORDER_MIDDLE);
144
145
146static int
147aw_rtc_probe(device_t dev)
148{
149	if (!ofw_bus_status_okay(dev))
150		return (ENXIO);
151
152	if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
153		return (ENXIO);
154
155	device_set_desc(dev, "Allwinner RTC");
156
157	return (BUS_PROBE_DEFAULT);
158}
159
160static int
161aw_rtc_attach(device_t dev)
162{
163	struct aw_rtc_softc *sc  = device_get_softc(dev);
164	bus_size_t rtc_losc_sta;
165	uint32_t val;
166	int rid = 0;
167
168	sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
169	if (!sc->res) {
170		device_printf(dev, "could not allocate resources\n");
171		return (ENXIO);
172	}
173
174	sc->type = ofw_bus_search_compatible(dev, compat_data)->ocd_data;
175	switch (sc->type) {
176	case A10_RTC:
177	case A20_RTC:
178		sc->rtc_date = A10_RTC_DATE_REG;
179		sc->rtc_time = A10_RTC_TIME_REG;
180		rtc_losc_sta = LOSC_CTRL_REG;
181		break;
182	case A31_RTC:
183		sc->rtc_date = A31_RTC_DATE_REG;
184		sc->rtc_time = A31_RTC_TIME_REG;
185		rtc_losc_sta = A31_LOSC_AUTO_SWT_STA;
186		break;
187	}
188	val = RTC_READ(sc, LOSC_CTRL_REG);
189	val |= LOSC_AUTO_SW_EN;
190	val |= LOSC_MAGIC | LOSC_GSM | LOSC_OSC_SRC;
191	RTC_WRITE(sc, LOSC_CTRL_REG, val);
192
193	DELAY(100);
194
195	if (bootverbose) {
196		val = RTC_READ(sc, rtc_losc_sta);
197		if ((val & LOSC_OSC_SRC) == 0)
198			device_printf(dev, "Using internal oscillator\n");
199		else
200			device_printf(dev, "Using external oscillator\n");
201	}
202
203	clock_register(dev, RTC_RES_US);
204
205	return (0);
206}
207
208static int
209aw_rtc_detach(device_t dev)
210{
211	/* can't support detach, since there's no clock_unregister function */
212	return (EBUSY);
213}
214
215static int
216aw_rtc_gettime(device_t dev, struct timespec *ts)
217{
218	struct aw_rtc_softc *sc  = device_get_softc(dev);
219	struct clocktime ct;
220	uint32_t rdate, rtime;
221
222	rdate = RTC_READ(sc, sc->rtc_date);
223	rtime = RTC_READ(sc, sc->rtc_time);
224
225	if ((rtime & TIME_MASK) == 0)
226		rdate = RTC_READ(sc, sc->rtc_date);
227
228	ct.sec = GET_SEC_VALUE(rtime);
229	ct.min = GET_MIN_VALUE(rtime);
230	ct.hour = GET_HOUR_VALUE(rtime);
231	ct.day = GET_DAY_VALUE(rdate);
232	ct.mon = GET_MON_VALUE(rdate);
233	ct.year = GET_YEAR_VALUE(rdate) + YEAR_OFFSET;
234	ct.dow = -1;
235	/* RTC resolution is 1 sec */
236	ct.nsec = 0;
237
238	return (clock_ct_to_ts(&ct, ts));
239}
240
241static int
242aw_rtc_settime(device_t dev, struct timespec *ts)
243{
244	struct aw_rtc_softc *sc  = device_get_softc(dev);
245	struct clocktime ct;
246	uint32_t clk, rdate, rtime;
247
248	/* RTC resolution is 1 sec */
249	if (ts->tv_nsec >= HALF_OF_SEC_NS)
250		ts->tv_sec++;
251	ts->tv_nsec = 0;
252
253	clock_ts_to_ct(ts, &ct);
254
255	if ((ct.year < YEAR_MIN) || (ct.year > YEAR_MAX)) {
256		device_printf(dev, "could not set time, year out of range\n");
257		return (EINVAL);
258	}
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	/* reset time register to avoid unexpected date increment */
268	RTC_WRITE(sc, sc->rtc_time, 0);
269
270	rdate = SET_DAY_VALUE(ct.day) | SET_MON_VALUE(ct.mon) |
271		SET_YEAR_VALUE(ct.year - YEAR_OFFSET) |
272		SET_LEAP_VALUE(IS_LEAP_YEAR(ct.year));
273
274	rtime = SET_SEC_VALUE(ct.sec) | SET_MIN_VALUE(ct.min) |
275		SET_HOUR_VALUE(ct.hour);
276
277	for (clk = 0; RTC_READ(sc, LOSC_CTRL_REG) & LOSC_BUSY_MASK; clk++) {
278		if (clk > RTC_TIMEOUT) {
279			device_printf(dev, "could not set date, RTC busy\n");
280			return (EINVAL);
281		}
282		DELAY(1);
283	}
284	RTC_WRITE(sc, sc->rtc_date, rdate);
285
286	for (clk = 0; RTC_READ(sc, LOSC_CTRL_REG) & LOSC_BUSY_MASK; clk++) {
287		if (clk > RTC_TIMEOUT) {
288			device_printf(dev, "could not set time, RTC busy\n");
289			return (EINVAL);
290		}
291		DELAY(1);
292	}
293	RTC_WRITE(sc, sc->rtc_time, rtime);
294
295	DELAY(RTC_TIMEOUT);
296
297	return (0);
298}
299