xref: /freebsd/sys/riscv/sifive/fe310_aon.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2019 Axiado Corporation
5  * All rights reserved.
6  *
7  * This software was developed in part by Nick O'Brien and Rishul Naik
8  * for Axiado Corporation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/bus.h>
36 #include <sys/clock.h>
37 #include <sys/eventhandler.h>
38 #include <sys/kernel.h>
39 #include <sys/lock.h>
40 #include <sys/module.h>
41 #include <sys/mutex.h>
42 #include <sys/rman.h>
43 #include <sys/sdt.h>
44 #include <sys/time.h>
45 #include <sys/timespec.h>
46 #include <sys/timex.h>
47 #include <sys/watchdog.h>
48 
49 #include <dev/ofw/ofw_bus.h>
50 #include <dev/ofw/ofw_bus_subr.h>
51 
52 #include <machine/bus.h>
53 #include <machine/clock.h>
54 #include <machine/intr.h>
55 #include <machine/resource.h>
56 
57 #include "clock_if.h"
58 
59 #define FEAON_AON_WDT_BASE		0x0
60 #define FEAON_AON_RTC_BASE		0x40
61 #define FEAON_AON_CLKCFG_BASE		0x70
62 #define FEAON_AON_BACKUP_BASE		0x80
63 #define FEAON_AON_PMU_BASE		0x100
64 
65 /* Watchdog specific */
66 #define FEAON_WDT_CFG			0x0
67 #define FEAON_WDT_COUNT			0x8
68 #define FEAON_WDT_DOGS			0x10
69 #define FEAON_WDT_FEED			0x18
70 #define FEAON_WDT_KEY			0x1C
71 #define FEAON_WDT_CMP			0x20
72 
73 #define FEAON_WDT_CFG_SCALE_MASK	0xF
74 #define FEAON_WDT_CFG_RST_EN		(1 << 8)
75 #define FEAON_WDT_CFG_ZERO_CMP		(1 << 9)
76 #define FEAON_WDT_CFG_EN_ALWAYS		(1 << 12)
77 #define FEAON_WDT_CFG_EN_CORE_AWAKE	(1 << 13)
78 #define FEAON_WDT_CFG_IP		(1 << 28)
79 
80 #define FEAON_WDT_CMP_MASK		0xFFFF
81 
82 #define FEAON_WDT_FEED_FOOD		0xD09F00D
83 
84 #define FEAON_WDT_KEY_UNLOCK		0x51F15E
85 
86 #define FEAON_WDT_TIMEBASE_FREQ		31250
87 #define FEAON_WDT_TIMEBASE_RATIO	(NANOSECOND / FEAON_WDT_TIMEBASE_FREQ)
88 
89 /* Real-time clock specific */
90 #define FEAON_RTC_CFG			0x40
91 #define FEAON_RTC_LO			0x48
92 #define FEAON_RTC_HI			0x4C
93 #define FEAON_RTC_CMP			0x60
94 
95 #define FEAON_RTC_CFG_SCALE_MASK	0xF
96 #define FEAON_RTC_CFG_EN		(1 << 12)
97 #define FEAON_RTC_CFG_IP		(1 << 28)
98 
99 #define FEAON_RTC_HI_MASK		0xFFFF
100 
101 #define FEAON_RTC_TIMEBASE_FREQ		31250LL
102 
103 #define FEAON_LOCK(sc)			mtx_lock(&(sc)->mtx)
104 #define FEAON_UNLOCK(sc)		mtx_unlock(&(sc)->mtx)
105 #define FEAON_ASSERT_LOCKED(sc)		mtx_assert(&(sc)->mtx, MA_OWNED)
106 #define FEAON_ASSERT_UNLOCKED(sc)	mtx_assert(&(sc)->mtx, MA_NOTOWNED)
107 
108 #define FEAON_READ_4(sc, reg)		bus_read_4(sc->reg_res, reg)
109 #define FEAON_WRITE_4(sc, reg, val)	bus_write_4(sc->reg_res, reg, val)
110 
111 #define FEAON_WDT_WRITE_4(sc, reg, val) do {					\
112 		FEAON_WRITE_4(sc, (FEAON_WDT_KEY), (FEAON_WDT_KEY_UNLOCK));	\
113 		FEAON_WRITE_4(sc, reg, val);					\
114 	} while (0)
115 
116 struct feaon_softc {
117 	device_t		dev;
118 	struct mtx		mtx;
119 
120 	/* Resources */
121 	int			reg_rid;
122 	struct resource		*reg_res;
123 
124 	/* WDT */
125 	eventhandler_tag	ev_tag;
126 };
127 
128 static void
129 feaon_wdt_event(void *arg, unsigned int cmd, int *err)
130 {
131 	struct feaon_softc *sc;
132 	uint32_t scale, val;
133 	uint64_t time;
134 
135 	sc = (struct feaon_softc *)arg;
136 	FEAON_LOCK(sc);
137 
138 	/* First feed WDT */
139 	FEAON_WDT_WRITE_4(sc, FEAON_WDT_FEED, FEAON_WDT_FEED_FOOD);
140 
141 	if ((cmd & WD_INTERVAL) == WD_TO_NEVER) {
142 		/* Disable WDT */
143 		val = FEAON_READ_4(sc, FEAON_WDT_CFG);
144 		val &= ~(FEAON_WDT_CFG_EN_ALWAYS | FEAON_WDT_CFG_EN_CORE_AWAKE);
145 		FEAON_WDT_WRITE_4(sc, FEAON_WDT_CFG, val);
146 		goto exit;
147 	}
148 
149 	/* Calculate time in WDT frequency */
150 	time = 1LL << (cmd & WD_INTERVAL);
151 	time /= FEAON_WDT_TIMEBASE_RATIO;
152 
153 	/* Fit time in CMP register with scale */
154 	scale = 0;
155 	while (time > FEAON_WDT_CMP_MASK) {
156 		time >>= 1;
157 		scale++;
158 	}
159 
160 	if (time > FEAON_WDT_CMP_MASK || scale > FEAON_WDT_CFG_SCALE_MASK) {
161 		device_printf(sc->dev, "Time interval too large for WDT\n");
162 		*err = EINVAL;
163 		goto exit;
164 	}
165 
166 	/* Program WDT */
167 	val = FEAON_READ_4(sc, FEAON_WDT_CFG);
168 	val &= ~FEAON_WDT_CFG_SCALE_MASK;
169 	val |= scale | FEAON_WDT_CFG_RST_EN | FEAON_WDT_CFG_EN_ALWAYS |
170 	    FEAON_WDT_CFG_ZERO_CMP;
171 
172 	FEAON_WDT_WRITE_4(sc, FEAON_WDT_CMP, (uint32_t)time);
173 	FEAON_WDT_WRITE_4(sc, FEAON_WDT_CFG, val);
174 
175 exit:
176 	FEAON_UNLOCK(sc);
177 }
178 
179 static int
180 feaon_rtc_settime(device_t dev, struct timespec *ts)
181 {
182 	struct feaon_softc *sc;
183 	uint64_t time;
184 	uint32_t cfg;
185 	uint8_t scale;
186 
187 	scale = 0;
188 	sc = device_get_softc(dev);
189 
190 	FEAON_LOCK(sc);
191 
192 	clock_dbgprint_ts(dev, CLOCK_DBG_WRITE, ts);
193 
194 	time = ts->tv_sec * FEAON_RTC_TIMEBASE_FREQ;
195 
196 	/* Find an appropriate scale */
197 	while (time >= 0xFFFFFFFFFFFFLL) {
198 		scale++;
199 		time >>= 1;
200 	}
201 	if (scale > FEAON_RTC_CFG_SCALE_MASK) {
202 		device_printf(sc->dev, "Time value too large for RTC\n");
203 		FEAON_UNLOCK(sc);
204 		return (1);
205 	}
206 	cfg = FEAON_READ_4(sc, FEAON_RTC_CFG) & ~FEAON_RTC_CFG_SCALE_MASK;
207 	cfg |= scale;
208 
209 	FEAON_WRITE_4(sc, FEAON_RTC_CFG, cfg);
210 	FEAON_WRITE_4(sc, FEAON_RTC_LO, (uint32_t)time);
211 	FEAON_WRITE_4(sc, FEAON_RTC_HI, (time >> 32) & FEAON_RTC_HI_MASK);
212 
213 	FEAON_UNLOCK(sc);
214 
215 	return (0);
216 }
217 
218 static int
219 feaon_rtc_gettime(device_t dev, struct timespec *ts)
220 {
221 	struct feaon_softc *sc;
222 	uint64_t time;
223 	uint8_t scale;
224 
225 	sc = device_get_softc(dev);
226 	FEAON_LOCK(sc);
227 
228 	time = FEAON_READ_4(sc, FEAON_RTC_LO);
229 	time |= ((uint64_t)FEAON_READ_4(sc, FEAON_RTC_HI)) << 32;
230 
231 	scale = FEAON_READ_4(sc, FEAON_RTC_CFG) & FEAON_RTC_CFG_SCALE_MASK;
232 	time <<= scale;
233 
234 	ts->tv_sec = time / FEAON_RTC_TIMEBASE_FREQ;
235 	ts->tv_nsec = (time % FEAON_RTC_TIMEBASE_FREQ) *
236 	    (NANOSECOND / FEAON_RTC_TIMEBASE_FREQ);
237 
238 	clock_dbgprint_ts(dev, CLOCK_DBG_READ, ts);
239 
240 	FEAON_UNLOCK(sc);
241 
242 	return (0);
243 }
244 
245 static int
246 feaon_attach(device_t dev)
247 {
248 	struct feaon_softc *sc;
249 	int err;
250 
251 	sc = device_get_softc(dev);
252 	sc->dev = dev;
253 
254 	/* Mutex setup */
255 	mtx_init(&sc->mtx, device_get_nameunit(sc->dev), NULL, MTX_DEF);
256 
257 	/* Resource setup */
258 	sc->reg_rid = 0;
259 	if ((sc->reg_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
260 	    &sc->reg_rid, RF_ACTIVE)) == NULL) {
261 		device_printf(dev, "Error allocating memory resource.\n");
262 		err = ENXIO;
263 		goto error;
264 	}
265 
266 	/* Enable RTC */
267 	clock_register(dev, 1000000); /* 1 sec resolution */
268 	FEAON_LOCK(sc);
269 	FEAON_WRITE_4(sc, FEAON_RTC_CFG, FEAON_RTC_CFG_EN);
270 	FEAON_UNLOCK(sc);
271 
272 	/* Register WDT */
273 	sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, feaon_wdt_event, sc, 0);
274 
275 	return (0);
276 
277 error:
278 	bus_release_resource(dev, SYS_RES_MEMORY, sc->reg_rid, sc->reg_res);
279 	mtx_destroy(&sc->mtx);
280 	return (err);
281 }
282 
283 static int
284 feaon_probe(device_t dev)
285 {
286 
287 	if (!ofw_bus_status_okay(dev))
288 		return (ENXIO);
289 
290 	if (!ofw_bus_is_compatible(dev, "sifive,aon0"))
291 		return (ENXIO);
292 
293 	device_set_desc(dev, "SiFive FE310 Always-On Controller");
294 	return (BUS_PROBE_DEFAULT);
295 }
296 
297 static device_method_t feaon_methods[] = {
298 	DEVMETHOD(device_probe, feaon_probe),
299 	DEVMETHOD(device_attach, feaon_attach),
300 
301 	/* RTC */
302 	DEVMETHOD(clock_gettime, feaon_rtc_gettime),
303 	DEVMETHOD(clock_settime, feaon_rtc_settime),
304 
305 	DEVMETHOD_END
306 };
307 
308 static driver_t feaon_driver = {
309 	"fe310aon",
310 	feaon_methods,
311 	sizeof(struct feaon_softc)
312 };
313 
314 DRIVER_MODULE(fe310aon, simplebus, feaon_driver, 0, 0);
315