xref: /freebsd/sys/arm/ti/am335x/am335x_rtc.c (revision 5ffd83dbcc34f10e07f6d3e968ae6365869615f4)
1 /*-
2  * Copyright (c) 2015 Luiz Otavio O Souza <loos@FreeBSD.org>
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/systm.h>
32 #include <sys/bus.h>
33 #include <sys/clock.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/module.h>
37 #include <sys/mutex.h>
38 #include <sys/rman.h>
39 
40 #include <machine/bus.h>
41 
42 #include <dev/ofw/ofw_bus.h>
43 #include <dev/ofw/ofw_bus_subr.h>
44 #include <arm/ti/ti_sysc.h>
45 #include <arm/ti/am335x/am335x_rtcvar.h>
46 #include <arm/ti/am335x/am335x_rtcreg.h>
47 
48 #define	RTC_LOCK(_sc)		mtx_lock(&(_sc)->sc_mtx)
49 #define	RTC_UNLOCK(_sc)		mtx_unlock(&(_sc)->sc_mtx)
50 #define	RTC_LOCK_INIT(_sc)	mtx_init(&(_sc)->sc_mtx, \
51     device_get_nameunit(_sc->sc_dev), "am335x_rtc", MTX_DEF)
52 #define	RTC_LOCK_DESTROY(_sc)	mtx_destroy(&(_sc)->sc_mtx)
53 
54 #define	RTC_READ4(_sc, reg)		\
55 	bus_read_4((_sc)->sc_mem_res, reg)
56 #define	RTC_WRITE4(_sc, reg, value)	\
57 	bus_write_4((_sc)->sc_mem_res, reg, value)
58 
59 #define	RTC_MAXIRQS		2
60 
61 struct am335x_rtc_softc {
62 	device_t		sc_dev;
63 	struct mtx		sc_mtx;
64 	struct resource		*sc_irq_res[RTC_MAXIRQS];
65 	struct resource		*sc_mem_res;
66 };
67 
68 static struct am335x_rtc_softc *rtc_sc = NULL;
69 static struct resource_spec am335x_rtc_irq_spec[] = {
70 	{ SYS_RES_IRQ, 0,  RF_ACTIVE },
71 	{ SYS_RES_IRQ, 1,  RF_ACTIVE },
72 	{ -1, 0,  0 }
73 };
74 
75 static int
76 am335x_rtc_probe(device_t dev)
77 {
78 
79 	if (!ofw_bus_status_okay(dev))
80 		return (ENXIO);
81 	if (!ofw_bus_is_compatible(dev, "ti,da830-rtc"))
82 		return (ENXIO);
83 	device_set_desc(dev, "AM335x RTC (power management mode)");
84 
85 	return (BUS_PROBE_DEFAULT);
86 }
87 
88 static int
89 am335x_rtc_attach(device_t dev)
90 {
91 	int rid;
92 	struct am335x_rtc_softc *sc;
93 	uint32_t rev;
94 
95 	if (rtc_sc != NULL)
96 		return (ENXIO);
97 	rtc_sc = sc = device_get_softc(dev);
98 	sc->sc_dev = dev;
99 	rid = 0;
100 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
101 	    RF_ACTIVE);
102 	if (!sc->sc_mem_res) {
103 		device_printf(dev, "cannot allocate memory resources\n");
104 		return (ENXIO);
105 	}
106 	if (bus_alloc_resources(dev, am335x_rtc_irq_spec, sc->sc_irq_res) != 0) {
107 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
108 		device_printf(dev, "cannot allocate irq resources\n");
109 		return (ENXIO);
110 	}
111 	RTC_LOCK_INIT(sc);
112 
113 	/* Enable the RTC module. */
114 	ti_sysc_clock_enable(device_get_parent(dev));
115 	rev = RTC_READ4(sc, RTC_REVISION);
116 	device_printf(dev, "AM335X RTC v%d.%d.%d\n",
117             (rev >> 8) & 0x7, (rev >> 6) & 0x3, rev & 0x3f);
118 	/* Unlock the RTC. */
119 	RTC_WRITE4(sc, RTC_KICK0R, RTC_KICK0R_PASS);
120 	RTC_WRITE4(sc, RTC_KICK1R, RTC_KICK1R_PASS);
121 	/* Stop the RTC, we don't need it right now. */
122 	RTC_WRITE4(sc, RTC_CTRL, 0);
123 	/* Disable interrupts. */
124 	RTC_WRITE4(sc, RTC_INTR, 0);
125 	/* Ack any pending interrupt. */
126 	RTC_WRITE4(sc, RTC_STATUS, RTC_STATUS_ALARM2 | RTC_STATUS_ALARM);
127 	/* Enable external clock (xtal) and 32 kHz clock. */
128 	RTC_WRITE4(sc, RTC_OSC, RTC_OSC_32KCLK_EN | RTC_OSC_32KCLK_SEL);
129 	/* Enable pmic_pwr_enable. */
130 	RTC_WRITE4(sc, RTC_PMIC, PMIC_PWR_ENABLE);
131 
132 	return (0);
133 }
134 
135 static int
136 am335x_rtc_detach(device_t dev)
137 {
138 	struct am335x_rtc_softc *sc;
139 
140 	sc = device_get_softc(dev);
141 	if (sc->sc_irq_res[0] != NULL)
142 		bus_release_resources(dev, am335x_rtc_irq_spec, sc->sc_irq_res);
143 	if (sc->sc_mem_res)
144 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
145 	RTC_LOCK_DESTROY(sc);
146 
147 	return (0);
148 }
149 
150 void
151 am335x_rtc_pmic_pwr_toggle(void)
152 {
153 	int timeout;
154 	struct clocktime ct;
155 	struct timespec ts;
156 
157 	/*
158 	 * We stop the RTC so we don't need to check the STATUS.BUSY bit
159 	 * before update ALARM2 registers.
160 	 */
161 	timeout = 10;
162 	RTC_WRITE4(rtc_sc, RTC_CTRL, 0);
163 	while (--timeout && RTC_READ4(rtc_sc, RTC_STATUS) & RTC_STATUS_RUN)
164 		DELAY(100);
165 	if (timeout == 0) {
166 		device_printf(rtc_sc->sc_dev, "RTC does not stop.\n");
167 		return;
168 	}
169 	/* Program the ALARM2 to fire in 2 seconds. */
170 	ct.dow = 0;
171 	ct.nsec = 0;
172 	ct.sec = FROMBCD(RTC_READ4(rtc_sc, RTC_SECONDS) & 0x7f);
173 	ct.min = FROMBCD(RTC_READ4(rtc_sc, RTC_MINUTES) & 0x7f);
174 	ct.hour = FROMBCD(RTC_READ4(rtc_sc, RTC_HOURS) & 0x3f);
175 	ct.day = FROMBCD(RTC_READ4(rtc_sc, RTC_DAYS) & 0x3f);
176 	ct.mon = FROMBCD(RTC_READ4(rtc_sc, RTC_MONTHS) & 0x1f);
177 	ct.year = FROMBCD(RTC_READ4(rtc_sc, RTC_YEARS) & 0xff);
178 	ct.year += POSIX_BASE_YEAR;
179 	clock_ct_to_ts(&ct, &ts);
180 	ts.tv_sec += 2;
181 	clock_ts_to_ct(&ts, &ct);
182 	RTC_WRITE4(rtc_sc, RTC_ALARM2_SECONDS, TOBCD(ct.sec));
183 	RTC_WRITE4(rtc_sc, RTC_ALARM2_MINUTES, TOBCD(ct.min));
184 	RTC_WRITE4(rtc_sc, RTC_ALARM2_HOURS, TOBCD(ct.hour));
185 	RTC_WRITE4(rtc_sc, RTC_ALARM2_DAYS, TOBCD(ct.day));
186 	RTC_WRITE4(rtc_sc, RTC_ALARM2_MONTHS, TOBCD(ct.mon));
187 	RTC_WRITE4(rtc_sc, RTC_ALARM2_YEARS, TOBCD(ct.year - POSIX_BASE_YEAR));
188 	/* Enable ALARM2 interrupt. */
189 	RTC_WRITE4(rtc_sc, RTC_INTR, RTC_INTR_ALARM2);
190 	/* Start count. */
191 	RTC_WRITE4(rtc_sc, RTC_CTRL, RTC_CTRL_RUN);
192 }
193 
194 static device_method_t am335x_rtc_methods[] = {
195 	DEVMETHOD(device_probe,		am335x_rtc_probe),
196 	DEVMETHOD(device_attach,	am335x_rtc_attach),
197 	DEVMETHOD(device_detach,	am335x_rtc_detach),
198 
199 	DEVMETHOD_END
200 };
201 
202 static driver_t am335x_rtc_driver = {
203 	"am335x_rtc",
204 	am335x_rtc_methods,
205 	sizeof(struct am335x_rtc_softc),
206 };
207 
208 static devclass_t am335x_rtc_devclass;
209 
210 DRIVER_MODULE(am335x_rtc, simplebus, am335x_rtc_driver, am335x_rtc_devclass, 0, 0);
211 MODULE_VERSION(am335x_rtc, 1);
212 MODULE_DEPEND(am335x_rtc, simplebus, 1, 1, 1);
213 MODULE_DEPEND(am335x_rtc, ti_sysc, 1, 1, 1);
214