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
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
|
/*
* MAXIM DS1338 I2C RTC+NVRAM
*
* Copyright (c) 2009 CodeSourcery.
* Written by Paul Brook
*
* This code is licensed under the GNU GPL v2.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "i2c.h"
/* Size of NVRAM including both the user-accessible area and the
* secondary register area.
*/
#define NVRAM_SIZE 64
/* Flags definitions */
#define SECONDS_CH 0x80
#define HOURS_12 0x40
#define HOURS_PM 0x20
#define CTRL_OSF 0x20
typedef struct {
I2CSlave i2c;
int64_t offset;
uint8_t wday_offset;
uint8_t nvram[NVRAM_SIZE];
int32_t ptr;
bool addr_byte;
} DS1338State;
static const VMStateDescription vmstate_ds1338 = {
.name = "ds1338",
.version_id = 2,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.fields = (VMStateField[]) {
VMSTATE_I2C_SLAVE(i2c, DS1338State),
VMSTATE_INT64(offset, DS1338State),
VMSTATE_UINT8_V(wday_offset, DS1338State, 2),
VMSTATE_UINT8_ARRAY(nvram, DS1338State, NVRAM_SIZE),
VMSTATE_INT32(ptr, DS1338State),
VMSTATE_BOOL(addr_byte, DS1338State),
VMSTATE_END_OF_LIST()
}
};
static void capture_current_time(DS1338State *s)
{
/* Capture the current time into the secondary registers
* which will be actually read by the data transfer operation.
*/
struct tm now;
qemu_get_timedate(&now, s->offset);
s->nvram[0] = to_bcd(now.tm_sec);
s->nvram[1] = to_bcd(now.tm_min);
if (s->nvram[2] & HOURS_12) {
int tmp = now.tm_hour;
if (tmp % 12 == 0) {
tmp += 12;
}
if (tmp <= 12) {
s->nvram[2] = HOURS_12 | to_bcd(tmp);
} else {
s->nvram[2] = HOURS_12 | HOURS_PM | to_bcd(tmp - 12);
}
} else {
s->nvram[2] = to_bcd(now.tm_hour);
}
s->nvram[3] = (now.tm_wday + s->wday_offset) % 7 + 1;
s->nvram[4] = to_bcd(now.tm_mday);
s->nvram[5] = to_bcd(now.tm_mon + 1);
s->nvram[6] = to_bcd(now.tm_year - 100);
}
static void inc_regptr(DS1338State *s)
{
/* The register pointer wraps around after 0x3F; wraparound
* causes the current time/date to be retransferred into
* the secondary registers.
*/
s->ptr = (s->ptr + 1) & (NVRAM_SIZE - 1);
if (!s->ptr) {
capture_current_time(s);
}
}
static void ds1338_event(I2CSlave *i2c, enum i2c_event event)
{
DS1338State *s = FROM_I2C_SLAVE(DS1338State, i2c);
switch (event) {
case I2C_START_RECV:
/* In h/w, capture happens on any START condition, not just a
* START_RECV, but there is no need to actually capture on
* START_SEND, because the guest can't get at that data
* without going through a START_RECV which would overwrite it.
*/
capture_current_time(s);
break;
case I2C_START_SEND:
s->addr_byte = true;
break;
default:
break;
}
}
static int ds1338_recv(I2CSlave *i2c)
{
DS1338State *s = FROM_I2C_SLAVE(DS1338State, i2c);
uint8_t res;
res = s->nvram[s->ptr];
inc_regptr(s);
return res;
}
static int ds1338_send(I2CSlave *i2c, uint8_t data)
{
DS1338State *s = FROM_I2C_SLAVE(DS1338State, i2c);
if (s->addr_byte) {
s->ptr = data & (NVRAM_SIZE - 1);
s->addr_byte = false;
return 0;
}
if (s->ptr < 7) {
/* Time register. */
struct tm now;
qemu_get_timedate(&now, s->offset);
switch(s->ptr) {
case 0:
/* TODO: Implement CH (stop) bit. */
now.tm_sec = from_bcd(data & 0x7f);
break;
case 1:
now.tm_min = from_bcd(data & 0x7f);
break;
case 2:
if (data & HOURS_12) {
int tmp = from_bcd(data & (HOURS_PM - 1));
if (data & HOURS_PM) {
tmp += 12;
}
if (tmp % 12 == 0) {
tmp -= 12;
}
now.tm_hour = tmp;
} else {
now.tm_hour = from_bcd(data & (HOURS_12 - 1));
}
break;
case 3:
{
/* The day field is supposed to contain a value in
the range 1-7. Otherwise behavior is undefined.
*/
int user_wday = (data & 7) - 1;
s->wday_offset = (user_wday - now.tm_wday + 7) % 7;
}
break;
case 4:
now.tm_mday = from_bcd(data & 0x3f);
break;
case 5:
now.tm_mon = from_bcd(data & 0x1f) - 1;
break;
case 6:
now.tm_year = from_bcd(data) + 100;
break;
}
s->offset = qemu_timedate_diff(&now);
} else if (s->ptr == 7) {
/* Control register. */
/* Ensure bits 2, 3 and 6 will read back as zero. */
data &= 0xB3;
/* Attempting to write the OSF flag to logic 1 leaves the
value unchanged. */
data = (data & ~CTRL_OSF) | (data & s->nvram[s->ptr] & CTRL_OSF);
s->nvram[s->ptr] = data;
} else {
s->nvram[s->ptr] = data;
}
inc_regptr(s);
return 0;
}
static int ds1338_init(I2CSlave *i2c)
{
return 0;
}
static void ds1338_reset(DeviceState *dev)
{
DS1338State *s = FROM_I2C_SLAVE(DS1338State, I2C_SLAVE(dev));
/* The clock is running and synchronized with the host */
s->offset = 0;
s->wday_offset = 0;
memset(s->nvram, 0, NVRAM_SIZE);
s->ptr = 0;
s->addr_byte = false;
}
static void ds1338_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
k->init = ds1338_init;
k->event = ds1338_event;
k->recv = ds1338_recv;
k->send = ds1338_send;
dc->reset = ds1338_reset;
dc->vmsd = &vmstate_ds1338;
}
static const TypeInfo ds1338_info = {
.name = "ds1338",
.parent = TYPE_I2C_SLAVE,
.instance_size = sizeof(DS1338State),
.class_init = ds1338_class_init,
};
static void ds1338_register_types(void)
{
type_register_static(&ds1338_info);
}
type_init(ds1338_register_types)
|
