1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
/*
* ARM AMBA PrimeCell PL031 RTC
*
* Copyright (c) 2007 CodeSourcery
*
* This file is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include "hw.h"
#include "primecell.h"
#include "qemu-timer.h"
#include "sysemu.h"
//#define DEBUG_PL031
#ifdef DEBUG_PL031
#define DPRINTF(fmt, args...) \
do { printf("pl031: " fmt , ##args); } while (0)
#else
#define DPRINTF(fmt, args...) do {} while(0)
#endif
#define RTC_DR 0x00 /* Data read register */
#define RTC_MR 0x04 /* Match register */
#define RTC_LR 0x08 /* Data load register */
#define RTC_CR 0x0c /* Control register */
#define RTC_IMSC 0x10 /* Interrupt mask and set register */
#define RTC_RIS 0x14 /* Raw interrupt status register */
#define RTC_MIS 0x18 /* Masked interrupt status register */
#define RTC_ICR 0x1c /* Interrupt clear register */
typedef struct {
QEMUTimer *timer;
qemu_irq irq;
uint64_t start_time;
uint32_t tick_offset;
uint32_t mr;
uint32_t lr;
uint32_t cr;
uint32_t im;
uint32_t is;
} pl031_state;
static const unsigned char pl031_id[] = {
0x31, 0x10, 0x14, 0x00, /* Device ID */
0x0d, 0xf0, 0x05, 0xb1 /* Cell ID */
};
static void pl031_update(pl031_state *s)
{
qemu_set_irq(s->irq, s->is & s->im);
}
static void pl031_interrupt(void * opaque)
{
pl031_state *s = (pl031_state *)opaque;
s->im = 1;
DPRINTF("Alarm raised\n");
pl031_update(s);
}
static uint32_t pl031_get_count(pl031_state *s)
{
/* This assumes qemu_get_clock returns the time since the machine was
created. */
return s->tick_offset + qemu_get_clock(vm_clock) / ticks_per_sec;
}
static void pl031_set_alarm(pl031_state *s)
{
int64_t now;
uint32_t ticks;
now = qemu_get_clock(vm_clock);
ticks = s->tick_offset + now / ticks_per_sec;
/* The timer wraps around. This subtraction also wraps in the same way,
and gives correct results when alarm < now_ticks. */
ticks = s->mr - ticks;
DPRINTF("Alarm set in %ud ticks\n", ticks);
if (ticks == 0) {
qemu_del_timer(s->timer);
pl031_interrupt(s);
} else {
qemu_mod_timer(s->timer, now + (int64_t)ticks * ticks_per_sec);
}
}
static uint32_t pl031_read(void *opaque, target_phys_addr_t offset)
{
pl031_state *s = (pl031_state *)opaque;
if (offset >= 0xfe0 && offset < 0x1000)
return pl031_id[(offset - 0xfe0) >> 2];
switch (offset) {
case RTC_DR:
return pl031_get_count(s);
case RTC_MR:
return s->mr;
case RTC_IMSC:
return s->im;
case RTC_RIS:
return s->is;
case RTC_LR:
return s->lr;
case RTC_CR:
/* RTC is permanently enabled. */
return 1;
case RTC_MIS:
return s->is & s->im;
case RTC_ICR:
fprintf(stderr, "qemu: pl031_read: Unexpected offset 0x%x\n",
(int)offset);
break;
default:
cpu_abort(cpu_single_env, "pl031_read: Bad offset 0x%x\n",
(int)offset);
break;
}
return 0;
}
static void pl031_write(void * opaque, target_phys_addr_t offset,
uint32_t value)
{
pl031_state *s = (pl031_state *)opaque;
switch (offset) {
case RTC_LR:
s->tick_offset += value - pl031_get_count(s);
pl031_set_alarm(s);
break;
case RTC_MR:
s->mr = value;
pl031_set_alarm(s);
break;
case RTC_IMSC:
s->im = value & 1;
DPRINTF("Interrupt mask %d\n", s->im);
pl031_update(s);
break;
case RTC_ICR:
/* The PL031 documentation (DDI0224B) states that the interupt is
cleared when bit 0 of the written value is set. However the
arm926e documentation (DDI0287B) states that the interrupt is
cleared when any value is written. */
DPRINTF("Interrupt cleared");
s->is = 0;
pl031_update(s);
break;
case RTC_CR:
/* Written value is ignored. */
break;
case RTC_DR:
case RTC_MIS:
case RTC_RIS:
fprintf(stderr, "qemu: pl031_write: Unexpected offset 0x%x\n",
(int)offset);
break;
default:
cpu_abort(cpu_single_env, "pl031_write: Bad offset 0x%x\n",
(int)offset);
break;
}
}
static CPUWriteMemoryFunc * pl031_writefn[] = {
pl031_write,
pl031_write,
pl031_write
};
static CPUReadMemoryFunc * pl031_readfn[] = {
pl031_read,
pl031_read,
pl031_read
};
void pl031_init(uint32_t base, qemu_irq irq)
{
int iomemtype;
pl031_state *s;
struct tm tm;
s = qemu_mallocz(sizeof(pl031_state));
if (!s)
cpu_abort(cpu_single_env, "pl031_init: Out of memory\n");
iomemtype = cpu_register_io_memory(0, pl031_readfn, pl031_writefn, s);
if (iomemtype == -1)
cpu_abort(cpu_single_env, "pl031_init: Can't register I/O memory\n");
cpu_register_physical_memory(base, 0x00001000, iomemtype);
s->irq = irq;
/* ??? We assume vm_clock is zero at this point. */
qemu_get_timedate(&tm, 0);
s->tick_offset = mktimegm(&tm);
s->timer = qemu_new_timer(vm_clock, pl031_interrupt, s);
}
|
