1/*
2 * QEMU model of the Canon DIGIC timer block.
3 *
4 * Copyright (C) 2013 Antony Pavlov <antonynpavlov@gmail.com>
5 *
6 * This model is based on reverse engineering efforts
7 * made by CHDK (http://chdk.wikia.com) and
8 * Magic Lantern (http://www.magiclantern.fm) projects
9 * contributors.
10 *
11 * See "Timer/Clock Module" docs here:
12 * http://magiclantern.wikia.com/wiki/Register_Map
13 *
14 * The QEMU model of the OSTimer in PKUnity SoC by Guan Xuetao
15 * is used as a template.
16 *
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
21 *
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
26 *
27 */
28
29#include "qemu/osdep.h"
30#include "hw/sysbus.h"
31#include "hw/ptimer.h"
32#include "qemu/main-loop.h"
33#include "qemu/module.h"
34#include "qemu/log.h"
35
36#include "hw/timer/digic-timer.h"
37#include "migration/vmstate.h"
38
39static const VMStateDescription vmstate_digic_timer = {
40 .name = "digic.timer",
41 .version_id = 1,
42 .minimum_version_id = 1,
43 .fields = (VMStateField[]) {
44 VMSTATE_PTIMER(ptimer, DigicTimerState),
45 VMSTATE_UINT32(control, DigicTimerState),
46 VMSTATE_UINT32(relvalue, DigicTimerState),
47 VMSTATE_END_OF_LIST()
48 }
49};
50
51static void digic_timer_reset(DeviceState *dev)
52{
53 DigicTimerState *s = DIGIC_TIMER(dev);
54
55 ptimer_stop(s->ptimer);
56 s->control = 0;
57 s->relvalue = 0;
58}
59
60static uint64_t digic_timer_read(void *opaque, hwaddr offset, unsigned size)
61{
62 DigicTimerState *s = opaque;
63 uint64_t ret = 0;
64
65 switch (offset) {
66 case DIGIC_TIMER_CONTROL:
67 ret = s->control;
68 break;
69 case DIGIC_TIMER_RELVALUE:
70 ret = s->relvalue;
71 break;
72 case DIGIC_TIMER_VALUE:
73 ret = ptimer_get_count(s->ptimer) & 0xffff;
74 break;
75 default:
76 qemu_log_mask(LOG_UNIMP,
77 "digic-timer: read access to unknown register 0x"
78 TARGET_FMT_plx "\n", offset);
79 }
80
81 return ret;
82}
83
84static void digic_timer_write(void *opaque, hwaddr offset,
85 uint64_t value, unsigned size)
86{
87 DigicTimerState *s = opaque;
88
89 switch (offset) {
90 case DIGIC_TIMER_CONTROL:
91 if (value & DIGIC_TIMER_CONTROL_RST) {
92 digic_timer_reset((DeviceState *)s);
93 break;
94 }
95
96 if (value & DIGIC_TIMER_CONTROL_EN) {
97 ptimer_run(s->ptimer, 0);
98 }
99
100 s->control = (uint32_t)value;
101 break;
102
103 case DIGIC_TIMER_RELVALUE:
104 s->relvalue = extract32(value, 0, 16);
105 ptimer_set_limit(s->ptimer, s->relvalue, 1);
106 break;
107
108 case DIGIC_TIMER_VALUE:
109 break;
110
111 default:
112 qemu_log_mask(LOG_UNIMP,
113 "digic-timer: read access to unknown register 0x"
114 TARGET_FMT_plx "\n", offset);
115 }
116}
117
118static const MemoryRegionOps digic_timer_ops = {
119 .read = digic_timer_read,
120 .write = digic_timer_write,
121 .impl = {
122 .min_access_size = 4,
123 .max_access_size = 4,
124 },
125 .endianness = DEVICE_NATIVE_ENDIAN,
126};
127
128static void digic_timer_init(Object *obj)
129{
130 DigicTimerState *s = DIGIC_TIMER(obj);
131
132 s->ptimer = ptimer_init(NULL, PTIMER_POLICY_DEFAULT);
133
134 /*
135 * FIXME: there is no documentation on Digic timer
136 * frequency setup so let it always run at 1 MHz
137 */
138 ptimer_set_freq(s->ptimer, 1 * 1000 * 1000);
139
140 memory_region_init_io(&s->iomem, OBJECT(s), &digic_timer_ops, s,
141 TYPE_DIGIC_TIMER, 0x100);
142 sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem);
143}
144
145static void digic_timer_class_init(ObjectClass *klass, void *class_data)
146{
147 DeviceClass *dc = DEVICE_CLASS(klass);
148
149 dc->reset = digic_timer_reset;
150 dc->vmsd = &vmstate_digic_timer;
151}
152
153static const TypeInfo digic_timer_info = {
154 .name = TYPE_DIGIC_TIMER,
155 .parent = TYPE_SYS_BUS_DEVICE,
156 .instance_size = sizeof(DigicTimerState),
157 .instance_init = digic_timer_init,
158 .class_init = digic_timer_class_init,
159};
160
161static void digic_timer_register_type(void)
162{
163 type_register_static(&digic_timer_info);
164}
165
166type_init(digic_timer_register_type)
167