xen/pt: allow QEMU to request MSI unmasking at bind time
[qemu.git] / hw / timer / altera_timer.c
1 /*
2 * QEMU model of the Altera timer.
3 *
4 * Copyright (c) 2012 Chris Wulff <crwulff@gmail.com>
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see
18 * <http://www.gnu.org/licenses/lgpl-2.1.html>
19 */
20
21 #include "qemu/osdep.h"
22 #include "qemu-common.h"
23 #include "qapi/error.h"
24
25 #include "hw/sysbus.h"
26 #include "sysemu/sysemu.h"
27 #include "hw/ptimer.h"
28
29 #define R_STATUS 0
30 #define R_CONTROL 1
31 #define R_PERIODL 2
32 #define R_PERIODH 3
33 #define R_SNAPL 4
34 #define R_SNAPH 5
35 #define R_MAX 6
36
37 #define STATUS_TO 0x0001
38 #define STATUS_RUN 0x0002
39
40 #define CONTROL_ITO 0x0001
41 #define CONTROL_CONT 0x0002
42 #define CONTROL_START 0x0004
43 #define CONTROL_STOP 0x0008
44
45 #define TYPE_ALTERA_TIMER "ALTR.timer"
46 #define ALTERA_TIMER(obj) \
47 OBJECT_CHECK(AlteraTimer, (obj), TYPE_ALTERA_TIMER)
48
49 typedef struct AlteraTimer {
50 SysBusDevice busdev;
51 MemoryRegion mmio;
52 qemu_irq irq;
53 uint32_t freq_hz;
54 QEMUBH *bh;
55 ptimer_state *ptimer;
56 uint32_t regs[R_MAX];
57 } AlteraTimer;
58
59 static int timer_irq_state(AlteraTimer *t)
60 {
61 bool irq = (t->regs[R_STATUS] & STATUS_TO) &&
62 (t->regs[R_CONTROL] & CONTROL_ITO);
63 return irq;
64 }
65
66 static uint64_t timer_read(void *opaque, hwaddr addr,
67 unsigned int size)
68 {
69 AlteraTimer *t = opaque;
70 uint64_t r = 0;
71
72 addr >>= 2;
73
74 switch (addr) {
75 case R_CONTROL:
76 r = t->regs[R_CONTROL] & (CONTROL_ITO | CONTROL_CONT);
77 break;
78
79 default:
80 if (addr < ARRAY_SIZE(t->regs)) {
81 r = t->regs[addr];
82 }
83 break;
84 }
85
86 return r;
87 }
88
89 static void timer_write(void *opaque, hwaddr addr,
90 uint64_t value, unsigned int size)
91 {
92 AlteraTimer *t = opaque;
93 uint64_t tvalue;
94 uint32_t count = 0;
95 int irqState = timer_irq_state(t);
96
97 addr >>= 2;
98
99 switch (addr) {
100 case R_STATUS:
101 /* The timeout bit is cleared by writing the status register. */
102 t->regs[R_STATUS] &= ~STATUS_TO;
103 break;
104
105 case R_CONTROL:
106 t->regs[R_CONTROL] = value & (CONTROL_ITO | CONTROL_CONT);
107 if ((value & CONTROL_START) &&
108 !(t->regs[R_STATUS] & STATUS_RUN)) {
109 ptimer_run(t->ptimer, 1);
110 t->regs[R_STATUS] |= STATUS_RUN;
111 }
112 if ((value & CONTROL_STOP) && (t->regs[R_STATUS] & STATUS_RUN)) {
113 ptimer_stop(t->ptimer);
114 t->regs[R_STATUS] &= ~STATUS_RUN;
115 }
116 break;
117
118 case R_PERIODL:
119 case R_PERIODH:
120 t->regs[addr] = value & 0xFFFF;
121 if (t->regs[R_STATUS] & STATUS_RUN) {
122 ptimer_stop(t->ptimer);
123 t->regs[R_STATUS] &= ~STATUS_RUN;
124 }
125 tvalue = (t->regs[R_PERIODH] << 16) | t->regs[R_PERIODL];
126 ptimer_set_limit(t->ptimer, tvalue + 1, 1);
127 break;
128
129 case R_SNAPL:
130 case R_SNAPH:
131 count = ptimer_get_count(t->ptimer);
132 t->regs[R_SNAPL] = count & 0xFFFF;
133 t->regs[R_SNAPH] = count >> 16;
134 break;
135
136 default:
137 break;
138 }
139
140 if (irqState != timer_irq_state(t)) {
141 qemu_set_irq(t->irq, timer_irq_state(t));
142 }
143 }
144
145 static const MemoryRegionOps timer_ops = {
146 .read = timer_read,
147 .write = timer_write,
148 .endianness = DEVICE_NATIVE_ENDIAN,
149 .valid = {
150 .min_access_size = 1,
151 .max_access_size = 4
152 }
153 };
154
155 static void timer_hit(void *opaque)
156 {
157 AlteraTimer *t = opaque;
158 const uint64_t tvalue = (t->regs[R_PERIODH] << 16) | t->regs[R_PERIODL];
159
160 t->regs[R_STATUS] |= STATUS_TO;
161
162 ptimer_set_limit(t->ptimer, tvalue + 1, 1);
163
164 if (!(t->regs[R_CONTROL] & CONTROL_CONT)) {
165 t->regs[R_STATUS] &= ~STATUS_RUN;
166 ptimer_set_count(t->ptimer, tvalue);
167 } else {
168 ptimer_run(t->ptimer, 1);
169 }
170
171 qemu_set_irq(t->irq, timer_irq_state(t));
172 }
173
174 static void altera_timer_realize(DeviceState *dev, Error **errp)
175 {
176 AlteraTimer *t = ALTERA_TIMER(dev);
177 SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
178
179 if (t->freq_hz == 0) {
180 error_setg(errp, "\"clock-frequency\" property must be provided.");
181 return;
182 }
183
184 t->bh = qemu_bh_new(timer_hit, t);
185 t->ptimer = ptimer_init(t->bh, PTIMER_POLICY_DEFAULT);
186 ptimer_set_freq(t->ptimer, t->freq_hz);
187
188 memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t,
189 TYPE_ALTERA_TIMER, R_MAX * sizeof(uint32_t));
190 sysbus_init_mmio(sbd, &t->mmio);
191 }
192
193 static void altera_timer_init(Object *obj)
194 {
195 AlteraTimer *t = ALTERA_TIMER(obj);
196 SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
197
198 sysbus_init_irq(sbd, &t->irq);
199 }
200
201 static void altera_timer_reset(DeviceState *dev)
202 {
203 AlteraTimer *t = ALTERA_TIMER(dev);
204
205 ptimer_stop(t->ptimer);
206 ptimer_set_limit(t->ptimer, 0xffffffff, 1);
207 memset(t->regs, 0, sizeof(t->regs));
208 }
209
210 static Property altera_timer_properties[] = {
211 DEFINE_PROP_UINT32("clock-frequency", AlteraTimer, freq_hz, 0),
212 DEFINE_PROP_END_OF_LIST(),
213 };
214
215 static void altera_timer_class_init(ObjectClass *klass, void *data)
216 {
217 DeviceClass *dc = DEVICE_CLASS(klass);
218
219 dc->realize = altera_timer_realize;
220 dc->props = altera_timer_properties;
221 dc->reset = altera_timer_reset;
222 }
223
224 static const TypeInfo altera_timer_info = {
225 .name = TYPE_ALTERA_TIMER,
226 .parent = TYPE_SYS_BUS_DEVICE,
227 .instance_size = sizeof(AlteraTimer),
228 .instance_init = altera_timer_init,
229 .class_init = altera_timer_class_init,
230 };
231
232 static void altera_timer_register(void)
233 {
234 type_register_static(&altera_timer_info);
235 }
236
237 type_init(altera_timer_register)