2 * ARM AMBA PrimeCell PL031 RTC
4 * Copyright (c) 2007 CodeSourcery
6 * This file is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * Contributions after 2012-01-13 are licensed under the terms of the
11 * GNU GPL, version 2 or (at your option) any later version.
14 #include "qemu/osdep.h"
15 #include "qemu-common.h"
16 #include "hw/timer/pl031.h"
17 #include "hw/sysbus.h"
18 #include "qemu/timer.h"
19 #include "sysemu/sysemu.h"
20 #include "qemu/cutils.h"
22 #include "qemu/module.h"
25 #define RTC_DR 0x00 /* Data read register */
26 #define RTC_MR 0x04 /* Match register */
27 #define RTC_LR 0x08 /* Data load register */
28 #define RTC_CR 0x0c /* Control register */
29 #define RTC_IMSC 0x10 /* Interrupt mask and set register */
30 #define RTC_RIS 0x14 /* Raw interrupt status register */
31 #define RTC_MIS 0x18 /* Masked interrupt status register */
32 #define RTC_ICR 0x1c /* Interrupt clear register */
34 static const unsigned char pl031_id
[] = {
35 0x31, 0x10, 0x14, 0x00, /* Device ID */
36 0x0d, 0xf0, 0x05, 0xb1 /* Cell ID */
39 static void pl031_update(PL031State
*s
)
41 uint32_t flags
= s
->is
& s
->im
;
43 trace_pl031_irq_state(flags
);
44 qemu_set_irq(s
->irq
, flags
);
47 static void pl031_interrupt(void * opaque
)
49 PL031State
*s
= (PL031State
*)opaque
;
52 trace_pl031_alarm_raised();
56 static uint32_t pl031_get_count(PL031State
*s
)
58 int64_t now
= qemu_clock_get_ns(rtc_clock
);
59 return s
->tick_offset
+ now
/ NANOSECONDS_PER_SECOND
;
62 static void pl031_set_alarm(PL031State
*s
)
66 /* The timer wraps around. This subtraction also wraps in the same way,
67 and gives correct results when alarm < now_ticks. */
68 ticks
= s
->mr
- pl031_get_count(s
);
69 trace_pl031_set_alarm(ticks
);
74 int64_t now
= qemu_clock_get_ns(rtc_clock
);
75 timer_mod(s
->timer
, now
+ (int64_t)ticks
* NANOSECONDS_PER_SECOND
);
79 static uint64_t pl031_read(void *opaque
, hwaddr offset
,
82 PL031State
*s
= (PL031State
*)opaque
;
87 r
= pl031_get_count(s
);
102 /* RTC is permanently enabled. */
108 case 0xfe0 ... 0xfff:
109 r
= pl031_id
[(offset
- 0xfe0) >> 2];
112 qemu_log_mask(LOG_GUEST_ERROR
,
113 "pl031: read of write-only register at offset 0x%x\n",
118 qemu_log_mask(LOG_GUEST_ERROR
,
119 "pl031_read: Bad offset 0x%x\n", (int)offset
);
124 trace_pl031_read(offset
, r
);
128 static void pl031_write(void * opaque
, hwaddr offset
,
129 uint64_t value
, unsigned size
)
131 PL031State
*s
= (PL031State
*)opaque
;
133 trace_pl031_write(offset
, value
);
137 s
->tick_offset
+= value
- pl031_get_count(s
);
149 /* The PL031 documentation (DDI0224B) states that the interrupt is
150 cleared when bit 0 of the written value is set. However the
151 arm926e documentation (DDI0287B) states that the interrupt is
152 cleared when any value is written. */
157 /* Written value is ignored. */
163 qemu_log_mask(LOG_GUEST_ERROR
,
164 "pl031: write to read-only register at offset 0x%x\n",
169 qemu_log_mask(LOG_GUEST_ERROR
,
170 "pl031_write: Bad offset 0x%x\n", (int)offset
);
175 static const MemoryRegionOps pl031_ops
= {
177 .write
= pl031_write
,
178 .endianness
= DEVICE_NATIVE_ENDIAN
,
181 static void pl031_init(Object
*obj
)
183 PL031State
*s
= PL031(obj
);
184 SysBusDevice
*dev
= SYS_BUS_DEVICE(obj
);
187 memory_region_init_io(&s
->iomem
, obj
, &pl031_ops
, s
, "pl031", 0x1000);
188 sysbus_init_mmio(dev
, &s
->iomem
);
190 sysbus_init_irq(dev
, &s
->irq
);
191 qemu_get_timedate(&tm
, 0);
192 s
->tick_offset
= mktimegm(&tm
) -
193 qemu_clock_get_ns(rtc_clock
) / NANOSECONDS_PER_SECOND
;
195 s
->timer
= timer_new_ns(rtc_clock
, pl031_interrupt
, s
);
198 static int pl031_pre_save(void *opaque
)
200 PL031State
*s
= opaque
;
202 /* tick_offset is base_time - rtc_clock base time. Instead, we want to
203 * store the base time relative to the QEMU_CLOCK_VIRTUAL for backwards-compatibility. */
204 int64_t delta
= qemu_clock_get_ns(rtc_clock
) - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL
);
205 s
->tick_offset_vmstate
= s
->tick_offset
+ delta
/ NANOSECONDS_PER_SECOND
;
210 static int pl031_post_load(void *opaque
, int version_id
)
212 PL031State
*s
= opaque
;
214 int64_t delta
= qemu_clock_get_ns(rtc_clock
) - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL
);
215 s
->tick_offset
= s
->tick_offset_vmstate
- delta
/ NANOSECONDS_PER_SECOND
;
220 static const VMStateDescription vmstate_pl031
= {
223 .minimum_version_id
= 1,
224 .pre_save
= pl031_pre_save
,
225 .post_load
= pl031_post_load
,
226 .fields
= (VMStateField
[]) {
227 VMSTATE_UINT32(tick_offset_vmstate
, PL031State
),
228 VMSTATE_UINT32(mr
, PL031State
),
229 VMSTATE_UINT32(lr
, PL031State
),
230 VMSTATE_UINT32(cr
, PL031State
),
231 VMSTATE_UINT32(im
, PL031State
),
232 VMSTATE_UINT32(is
, PL031State
),
233 VMSTATE_END_OF_LIST()
237 static void pl031_class_init(ObjectClass
*klass
, void *data
)
239 DeviceClass
*dc
= DEVICE_CLASS(klass
);
241 dc
->vmsd
= &vmstate_pl031
;
244 static const TypeInfo pl031_info
= {
246 .parent
= TYPE_SYS_BUS_DEVICE
,
247 .instance_size
= sizeof(PL031State
),
248 .instance_init
= pl031_init
,
249 .class_init
= pl031_class_init
,
252 static void pl031_register_types(void)
254 type_register_static(&pl031_info
);
257 type_init(pl031_register_types
)