xref: /openbmc/qemu/hw/rtc/sun4v-rtc.c (revision 9f6df01d)
1 /*
2  * QEMU sun4v Real Time Clock device
3  *
4  * The sun4v_rtc device (sun4v tod clock)
5  *
6  * Copyright (c) 2016 Artyom Tarasenko
7  *
8  * This code is licensed under the GNU GPL v3 or (at your option) any later
9  * version.
10  */
11 
12 #include "qemu/osdep.h"
13 #include "hw/sysbus.h"
14 #include "qapi/error.h"
15 #include "qemu/module.h"
16 #include "qemu/timer.h"
17 #include "hw/rtc/sun4v-rtc.h"
18 #include "trace.h"
19 #include "qom/object.h"
20 
21 
22 #define TYPE_SUN4V_RTC "sun4v_rtc"
23 OBJECT_DECLARE_SIMPLE_TYPE(Sun4vRtc, SUN4V_RTC)
24 
25 struct Sun4vRtc {
26     SysBusDevice parent_obj;
27 
28     MemoryRegion iomem;
29 };
30 
31 static uint64_t sun4v_rtc_read(void *opaque, hwaddr addr,
32                                 unsigned size)
33 {
34     uint64_t val = get_clock_realtime() / NANOSECONDS_PER_SECOND;
35     if (!(addr & 4ULL)) {
36         /* accessing the high 32 bits */
37         val >>= 32;
38     }
39     trace_sun4v_rtc_read(addr, val);
40     return val;
41 }
42 
43 static void sun4v_rtc_write(void *opaque, hwaddr addr,
44                              uint64_t val, unsigned size)
45 {
46     trace_sun4v_rtc_write(addr, val);
47 }
48 
49 static const MemoryRegionOps sun4v_rtc_ops = {
50     .read = sun4v_rtc_read,
51     .write = sun4v_rtc_write,
52     .endianness = DEVICE_NATIVE_ENDIAN,
53 };
54 
55 void sun4v_rtc_init(hwaddr addr)
56 {
57     DeviceState *dev;
58     SysBusDevice *s;
59 
60     dev = qdev_new(TYPE_SUN4V_RTC);
61     s = SYS_BUS_DEVICE(dev);
62 
63     sysbus_realize_and_unref(s, &error_fatal);
64 
65     sysbus_mmio_map(s, 0, addr);
66 }
67 
68 static void sun4v_rtc_realize(DeviceState *dev, Error **errp)
69 {
70     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
71     Sun4vRtc *s = SUN4V_RTC(dev);
72 
73     memory_region_init_io(&s->iomem, OBJECT(s), &sun4v_rtc_ops, s,
74                           "sun4v-rtc", 0x08ULL);
75     sysbus_init_mmio(sbd, &s->iomem);
76 }
77 
78 static void sun4v_rtc_class_init(ObjectClass *klass, void *data)
79 {
80     DeviceClass *dc = DEVICE_CLASS(klass);
81 
82     dc->realize = sun4v_rtc_realize;
83 }
84 
85 static const TypeInfo sun4v_rtc_info = {
86     .name          = TYPE_SUN4V_RTC,
87     .parent        = TYPE_SYS_BUS_DEVICE,
88     .instance_size = sizeof(Sun4vRtc),
89     .class_init    = sun4v_rtc_class_init,
90 };
91 
92 static void sun4v_rtc_register_types(void)
93 {
94     type_register_static(&sun4v_rtc_info);
95 }
96 
97 type_init(sun4v_rtc_register_types)
98