xref: /freebsd/sys/riscv/sifive/fe310_aon.c (revision a84d91d81a6f3eeb4949c4fb3440e0634f2b953a)
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/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/clock.h>
36 #include <sys/eventhandler.h>
37 #include <sys/kernel.h>
38 #include <sys/lock.h>
39 #include <sys/module.h>
40 #include <sys/mutex.h>
41 #include <sys/rman.h>
42 #include <sys/sdt.h>
43 #include <sys/time.h>
44 #include <sys/timespec.h>
45 #include <sys/timex.h>
46 #include <sys/watchdog.h>
47 
48 #include <dev/ofw/ofw_bus.h>
49 #include <dev/ofw/ofw_bus_subr.h>
50 
51 #include <machine/bus.h>
52 #include <machine/clock.h>
53 #include <machine/intr.h>
54 #include <machine/resource.h>
55 
56 #include "clock_if.h"
57 
58 #define FEAON_AON_WDT_BASE		0x0
59 #define FEAON_AON_RTC_BASE		0x40
60 #define FEAON_AON_CLKCFG_BASE		0x70
61 #define FEAON_AON_BACKUP_BASE		0x80
62 #define FEAON_AON_PMU_BASE		0x100
63 
64 /* Watchdog specific */
65 #define FEAON_WDT_CFG			0x0
66 #define FEAON_WDT_COUNT			0x8
67 #define FEAON_WDT_DOGS			0x10
68 #define FEAON_WDT_FEED			0x18
69 #define FEAON_WDT_KEY			0x1C
70 #define FEAON_WDT_CMP			0x20
71 
72 #define FEAON_WDT_CFG_SCALE_MASK	0xF
73 #define FEAON_WDT_CFG_RST_EN		(1 << 8)
74 #define FEAON_WDT_CFG_ZERO_CMP		(1 << 9)
75 #define FEAON_WDT_CFG_EN_ALWAYS		(1 << 12)
76 #define FEAON_WDT_CFG_EN_CORE_AWAKE	(1 << 13)
77 #define FEAON_WDT_CFG_IP		(1 << 28)
78 
79 #define FEAON_WDT_CMP_MASK		0xFFFF
80 
81 #define FEAON_WDT_FEED_FOOD		0xD09F00D
82 
83 #define FEAON_WDT_KEY_UNLOCK		0x51F15E
84 
85 #define FEAON_WDT_TIMEBASE_FREQ		31250
86 #define FEAON_WDT_TIMEBASE_RATIO	(NANOSECOND / FEAON_WDT_TIMEBASE_FREQ)
87 
88 /* Real-time clock specific */
89 #define FEAON_RTC_CFG			0x40
90 #define FEAON_RTC_LO			0x48
91 #define FEAON_RTC_HI			0x4C
92 #define FEAON_RTC_CMP			0x60
93 
94 #define FEAON_RTC_CFG_SCALE_MASK	0xF
95 #define FEAON_RTC_CFG_EN		(1 << 12)
96 #define FEAON_RTC_CFG_IP		(1 << 28)
97 
98 #define FEAON_RTC_HI_MASK		0xFFFF
99 
100 #define FEAON_RTC_TIMEBASE_FREQ		31250LL
101 
102 #define FEAON_LOCK(sc)			mtx_lock(&(sc)->mtx)
103 #define FEAON_UNLOCK(sc)		mtx_unlock(&(sc)->mtx)
104 #define FEAON_ASSERT_LOCKED(sc)		mtx_assert(&(sc)->mtx, MA_OWNED)
105 #define FEAON_ASSERT_UNLOCKED(sc)	mtx_assert(&(sc)->mtx, MA_NOTOWNED)
106 
107 #define FEAON_READ_4(sc, reg)		bus_read_4(sc->reg_res, reg)
108 #define FEAON_WRITE_4(sc, reg, val)	bus_write_4(sc->reg_res, reg, val)
109 
110 #define FEAON_WDT_WRITE_4(sc, reg, val) do {					\
111 		FEAON_WRITE_4(sc, (FEAON_WDT_KEY), (FEAON_WDT_KEY_UNLOCK));	\
112 		FEAON_WRITE_4(sc, reg, val);					\
113 	} while (0)
114 
115 struct feaon_softc {
116 	device_t		dev;
117 	struct mtx		mtx;
118 
119 	/* Resources */
120 	int			reg_rid;
121 	struct resource		*reg_res;
122 
123 	/* WDT */
124 	eventhandler_tag	ev_tag;
125 };
126 
127 static void
128 feaon_wdt_event(void *arg, unsigned int cmd, int *err)
129 {
130 	struct feaon_softc *sc;
131 	uint32_t scale, val;
132 	uint64_t time;
133 
134 	sc = (struct feaon_softc *)arg;
135 	FEAON_LOCK(sc);
136 
137 	/* First feed WDT */
138 	FEAON_WDT_WRITE_4(sc, FEAON_WDT_FEED, FEAON_WDT_FEED_FOOD);
139 
140 	if ((cmd & WD_INTERVAL) == WD_TO_NEVER) {
141 		/* Disable WDT */
142 		val = FEAON_READ_4(sc, FEAON_WDT_CFG);
143 		val &= ~(FEAON_WDT_CFG_EN_ALWAYS | FEAON_WDT_CFG_EN_CORE_AWAKE);
144 		FEAON_WDT_WRITE_4(sc, FEAON_WDT_CFG, val);
145 		goto exit;
146 	}
147 
148 	/* Calculate time in WDT frequency */
149 	time = 1LL << (cmd & WD_INTERVAL);
150 	time /= FEAON_WDT_TIMEBASE_RATIO;
151 
152 	/* Fit time in CMP register with scale */
153 	scale = 0;
154 	while (time > FEAON_WDT_CMP_MASK) {
155 		time >>= 1;
156 		scale++;
157 	}
158 
159 	if (time > FEAON_WDT_CMP_MASK || scale > FEAON_WDT_CFG_SCALE_MASK) {
160 		device_printf(sc->dev, "Time interval too large for WDT\n");
161 		*err = EINVAL;
162 		goto exit;
163 	}
164 
165 	/* Program WDT */
166 	val = FEAON_READ_4(sc, FEAON_WDT_CFG);
167 	val &= ~FEAON_WDT_CFG_SCALE_MASK;
168 	val |= scale | FEAON_WDT_CFG_RST_EN | FEAON_WDT_CFG_EN_ALWAYS |
169 	    FEAON_WDT_CFG_ZERO_CMP;
170 
171 	FEAON_WDT_WRITE_4(sc, FEAON_WDT_CMP, (uint32_t)time);
172 	FEAON_WDT_WRITE_4(sc, FEAON_WDT_CFG, val);
173 
174 exit:
175 	FEAON_UNLOCK(sc);
176 }
177 
178 static int
179 feaon_rtc_settime(device_t dev, struct timespec *ts)
180 {
181 	struct feaon_softc *sc;
182 	uint64_t time;
183 	uint32_t cfg;
184 	uint8_t scale;
185 
186 	scale = 0;
187 	sc = device_get_softc(dev);
188 
189 	FEAON_LOCK(sc);
190 
191 	clock_dbgprint_ts(dev, CLOCK_DBG_WRITE, ts);
192 
193 	time = ts->tv_sec * FEAON_RTC_TIMEBASE_FREQ;
194 
195 	/* Find an appropriate scale */
196 	while (time >= 0xFFFFFFFFFFFFLL) {
197 		scale++;
198 		time >>= 1;
199 	}
200 	if (scale > FEAON_RTC_CFG_SCALE_MASK) {
201 		device_printf(sc->dev, "Time value too large for RTC\n");
202 		FEAON_UNLOCK(sc);
203 		return (1);
204 	}
205 	cfg = FEAON_READ_4(sc, FEAON_RTC_CFG) & ~FEAON_RTC_CFG_SCALE_MASK;
206 	cfg |= scale;
207 
208 	FEAON_WRITE_4(sc, FEAON_RTC_CFG, cfg);
209 	FEAON_WRITE_4(sc, FEAON_RTC_LO, (uint32_t)time);
210 	FEAON_WRITE_4(sc, FEAON_RTC_HI, (time >> 32) & FEAON_RTC_HI_MASK);
211 
212 	FEAON_UNLOCK(sc);
213 
214 	return (0);
215 }
216 
217 static int
218 feaon_rtc_gettime(device_t dev, struct timespec *ts)
219 {
220 	struct feaon_softc *sc;
221 	uint64_t time;
222 	uint8_t scale;
223 
224 	sc = device_get_softc(dev);
225 	FEAON_LOCK(sc);
226 
227 	time = FEAON_READ_4(sc, FEAON_RTC_LO);
228 	time |= ((uint64_t)FEAON_READ_4(sc, FEAON_RTC_HI)) << 32;
229 
230 	scale = FEAON_READ_4(sc, FEAON_RTC_CFG) & FEAON_RTC_CFG_SCALE_MASK;
231 	time <<= scale;
232 
233 	ts->tv_sec = time / FEAON_RTC_TIMEBASE_FREQ;
234 	ts->tv_nsec = (time % FEAON_RTC_TIMEBASE_FREQ) *
235 	    (NANOSECOND / FEAON_RTC_TIMEBASE_FREQ);
236 
237 	clock_dbgprint_ts(dev, CLOCK_DBG_READ, ts);
238 
239 	FEAON_UNLOCK(sc);
240 
241 	return (0);
242 }
243 
244 static int
245 feaon_attach(device_t dev)
246 {
247 	struct feaon_softc *sc;
248 	int err;
249 
250 	sc = device_get_softc(dev);
251 	sc->dev = dev;
252 
253 	/* Mutex setup */
254 	mtx_init(&sc->mtx, device_get_nameunit(sc->dev), NULL, MTX_DEF);
255 
256 	/* Resource setup */
257 	sc->reg_rid = 0;
258 	if ((sc->reg_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
259 	    &sc->reg_rid, RF_ACTIVE)) == NULL) {
260 		device_printf(dev, "Error allocating memory resource.\n");
261 		err = ENXIO;
262 		goto error;
263 	}
264 
265 	/* Enable RTC */
266 	clock_register(dev, 1000000); /* 1 sec resolution */
267 	FEAON_LOCK(sc);
268 	FEAON_WRITE_4(sc, FEAON_RTC_CFG, FEAON_RTC_CFG_EN);
269 	FEAON_UNLOCK(sc);
270 
271 	/* Register WDT */
272 	sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, feaon_wdt_event, sc, 0);
273 
274 	return (0);
275 
276 error:
277 	bus_release_resource(dev, SYS_RES_MEMORY, sc->reg_rid, sc->reg_res);
278 	mtx_destroy(&sc->mtx);
279 	return (err);
280 }
281 
282 static int
283 feaon_probe(device_t dev)
284 {
285 
286 	if (!ofw_bus_status_okay(dev))
287 		return (ENXIO);
288 
289 	if (!ofw_bus_is_compatible(dev, "sifive,aon0"))
290 		return (ENXIO);
291 
292 	device_set_desc(dev, "SiFive FE310 Always-On Controller");
293 	return (BUS_PROBE_DEFAULT);
294 }
295 
296 static device_method_t feaon_methods[] = {
297 	DEVMETHOD(device_probe, feaon_probe),
298 	DEVMETHOD(device_attach, feaon_attach),
299 
300 	/* RTC */
301 	DEVMETHOD(clock_gettime, feaon_rtc_gettime),
302 	DEVMETHOD(clock_settime, feaon_rtc_settime),
303 
304 	DEVMETHOD_END
305 };
306 
307 static driver_t feaon_driver = {
308 	"fe310aon",
309 	feaon_methods,
310 	sizeof(struct feaon_softc)
311 };
312 
313 DRIVER_MODULE(fe310aon, simplebus, feaon_driver, 0, 0);
314