FreeBSD/Linux Kernel Cross Reference
sys/arm/lpc/lpc_rtc.c
1 /*-
2 * Copyright (c) 2011 Jakub Wojciech Klama <jceel@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: releng/10.0/sys/arm/lpc/lpc_rtc.c 239278 2012-08-15 05:37:10Z gonzo $");
29
30 #include <sys/param.h>
31 #include <sys/bus.h>
32 #include <sys/time.h>
33 #include <sys/clock.h>
34 #include <sys/resource.h>
35 #include <sys/systm.h>
36 #include <sys/rman.h>
37 #include <sys/kernel.h>
38 #include <sys/module.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/lpc/lpcreg.h>
47
48 #include "clock_if.h"
49
50 struct lpc_rtc_softc {
51 device_t lr_dev;
52 struct resource * lr_mem_res;
53 bus_space_tag_t lr_bst;
54 bus_space_handle_t lr_bsh;
55 };
56
57 static int lpc_rtc_probe(device_t dev);
58 static int lpc_rtc_attach(device_t dev);
59 static int lpc_rtc_gettime(device_t dev, struct timespec *ts);
60 static int lpc_rtc_settime(device_t, struct timespec *);
61
62 static int
63 lpc_rtc_probe(device_t dev)
64 {
65
66 if (!ofw_bus_is_compatible(dev, "lpc,rtc"))
67 return (ENXIO);
68
69 device_set_desc(dev, "LPC32x0 real time clock");
70 return (BUS_PROBE_DEFAULT);
71 }
72
73 static int
74 lpc_rtc_attach(device_t dev)
75 {
76 struct lpc_rtc_softc *sc = device_get_softc(dev);
77 int rid = 0;
78
79 sc->lr_dev = dev;
80
81 clock_register(dev, 1000000);
82
83 sc->lr_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
84 RF_ACTIVE);
85 if (!sc->lr_mem_res) {
86 device_printf(dev, "cannot allocate memory window\n");
87 return (ENXIO);
88 }
89
90 sc->lr_bst = rman_get_bustag(sc->lr_mem_res);
91 sc->lr_bsh = rman_get_bushandle(sc->lr_mem_res);
92
93 return (0);
94 }
95
96 static int
97 lpc_rtc_gettime(device_t dev, struct timespec *ts)
98 {
99 struct lpc_rtc_softc *sc = device_get_softc(dev);
100
101 ts->tv_sec = bus_space_read_4(sc->lr_bst, sc->lr_bsh, LPC_RTC_UCOUNT);
102 ts->tv_nsec = 0;
103
104 return (0);
105 }
106
107 static int
108 lpc_rtc_settime(device_t dev, struct timespec *ts)
109 {
110 struct lpc_rtc_softc *sc = device_get_softc(dev);
111 uint32_t ctrl;
112
113 /* Stop RTC */
114 ctrl = bus_space_read_4(sc->lr_bst, sc->lr_bsh, LPC_RTC_CTRL);
115 bus_space_write_4(sc->lr_bst, sc->lr_bsh, LPC_RTC_CTRL, ctrl | LPC_RTC_CTRL_DISABLE);
116
117 /* Write actual value */
118 bus_space_write_4(sc->lr_bst, sc->lr_bsh, LPC_RTC_UCOUNT, ts->tv_sec);
119
120 /* Start RTC */
121 ctrl = bus_space_read_4(sc->lr_bst, sc->lr_bsh, LPC_RTC_CTRL);
122 bus_space_write_4(sc->lr_bst, sc->lr_bsh, LPC_RTC_CTRL, ctrl & ~LPC_RTC_CTRL_DISABLE);
123
124 return (0);
125 }
126
127 static device_method_t lpc_rtc_methods[] = {
128 /* Device interface */
129 DEVMETHOD(device_probe, lpc_rtc_probe),
130 DEVMETHOD(device_attach, lpc_rtc_attach),
131
132 /* Clock interface */
133 DEVMETHOD(clock_gettime, lpc_rtc_gettime),
134 DEVMETHOD(clock_settime, lpc_rtc_settime),
135
136 { 0, 0 },
137 };
138
139 static driver_t lpc_rtc_driver = {
140 "rtc",
141 lpc_rtc_methods,
142 sizeof(struct lpc_rtc_softc),
143 };
144
145 static devclass_t lpc_rtc_devclass;
146
147 DRIVER_MODULE(rtc, simplebus, lpc_rtc_driver, lpc_rtc_devclass, 0, 0);
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