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Paul Brook1dfe3942009-11-20 00:21:33 +00001/*
2 * MAXIM DS1338 I2C RTC+NVRAM
3 *
4 * Copyright (c) 2009 CodeSourcery.
5 * Written by Paul Brook
6 *
Matthew Fernandez8e31bf32011-06-26 12:21:35 +10007 * This code is licensed under the GNU GPL v2.
Paolo Bonzini6b620ca2012-01-13 17:44:23 +01008 *
9 * Contributions after 2012-01-13 are licensed under the terms of the
10 * GNU GPL, version 2 or (at your option) any later version.
Paul Brook1dfe3942009-11-20 00:21:33 +000011 */
12
13#include "i2c.h"
14
15typedef struct {
Anthony Liguori9e07bdf2011-12-04 20:28:27 -060016 I2CSlave i2c;
Paul Brook1dfe3942009-11-20 00:21:33 +000017 time_t offset;
18 struct tm now;
19 uint8_t nvram[56];
20 int ptr;
21 int addr_byte;
22} DS1338State;
23
Anthony Liguori9e07bdf2011-12-04 20:28:27 -060024static void ds1338_event(I2CSlave *i2c, enum i2c_event event)
Paul Brook1dfe3942009-11-20 00:21:33 +000025{
26 DS1338State *s = FROM_I2C_SLAVE(DS1338State, i2c);
27
28 switch (event) {
29 case I2C_START_RECV:
30 qemu_get_timedate(&s->now, s->offset);
31 s->nvram[0] = to_bcd(s->now.tm_sec);
32 s->nvram[1] = to_bcd(s->now.tm_min);
33 if (s->nvram[2] & 0x40) {
34 s->nvram[2] = (to_bcd((s->now.tm_hour % 12)) + 1) | 0x40;
35 if (s->now.tm_hour >= 12) {
36 s->nvram[2] |= 0x20;
37 }
38 } else {
39 s->nvram[2] = to_bcd(s->now.tm_hour);
40 }
41 s->nvram[3] = to_bcd(s->now.tm_wday) + 1;
42 s->nvram[4] = to_bcd(s->now.tm_mday);
43 s->nvram[5] = to_bcd(s->now.tm_mon) + 1;
44 s->nvram[6] = to_bcd(s->now.tm_year - 100);
45 break;
46 case I2C_START_SEND:
47 s->addr_byte = 1;
48 break;
49 default:
50 break;
51 }
52}
53
Anthony Liguori9e07bdf2011-12-04 20:28:27 -060054static int ds1338_recv(I2CSlave *i2c)
Paul Brook1dfe3942009-11-20 00:21:33 +000055{
56 DS1338State *s = FROM_I2C_SLAVE(DS1338State, i2c);
57 uint8_t res;
58
59 res = s->nvram[s->ptr];
60 s->ptr = (s->ptr + 1) & 0xff;
61 return res;
62}
63
Anthony Liguori9e07bdf2011-12-04 20:28:27 -060064static int ds1338_send(I2CSlave *i2c, uint8_t data)
Paul Brook1dfe3942009-11-20 00:21:33 +000065{
66 DS1338State *s = FROM_I2C_SLAVE(DS1338State, i2c);
67 if (s->addr_byte) {
68 s->ptr = data;
69 s->addr_byte = 0;
70 return 0;
71 }
72 s->nvram[s->ptr - 8] = data;
73 if (data < 8) {
74 qemu_get_timedate(&s->now, s->offset);
75 switch(data) {
76 case 0:
77 /* TODO: Implement CH (stop) bit. */
78 s->now.tm_sec = from_bcd(data & 0x7f);
79 break;
80 case 1:
81 s->now.tm_min = from_bcd(data & 0x7f);
82 break;
83 case 2:
84 if (data & 0x40) {
85 if (data & 0x20) {
86 data = from_bcd(data & 0x4f) + 11;
87 } else {
88 data = from_bcd(data & 0x1f) - 1;
89 }
90 } else {
91 data = from_bcd(data);
92 }
93 s->now.tm_hour = data;
94 break;
95 case 3:
96 s->now.tm_wday = from_bcd(data & 7) - 1;
97 break;
98 case 4:
99 s->now.tm_mday = from_bcd(data & 0x3f);
100 break;
101 case 5:
102 s->now.tm_mon = from_bcd(data & 0x1f) - 1;
Stefan Weilfbac6a72012-02-25 14:50:25 +0100103 break;
Paul Brook1dfe3942009-11-20 00:21:33 +0000104 case 6:
105 s->now.tm_year = from_bcd(data) + 100;
106 break;
107 case 7:
108 /* Control register. Currently ignored. */
109 break;
110 }
111 s->offset = qemu_timedate_diff(&s->now);
112 }
113 s->ptr = (s->ptr + 1) & 0xff;
114 return 0;
115}
116
Anthony Liguori9e07bdf2011-12-04 20:28:27 -0600117static int ds1338_init(I2CSlave *i2c)
Paul Brook1dfe3942009-11-20 00:21:33 +0000118{
119 return 0;
120}
121
Anthony Liguorib5ea9322011-12-04 20:39:20 -0600122static void ds1338_class_init(ObjectClass *klass, void *data)
123{
124 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
125
126 k->init = ds1338_init;
127 k->event = ds1338_event;
128 k->recv = ds1338_recv;
129 k->send = ds1338_send;
130}
131
Anthony Liguori39bffca2011-12-07 21:34:16 -0600132static TypeInfo ds1338_info = {
133 .name = "ds1338",
134 .parent = TYPE_I2C_SLAVE,
135 .instance_size = sizeof(DS1338State),
136 .class_init = ds1338_class_init,
Paul Brook1dfe3942009-11-20 00:21:33 +0000137};
138
Andreas Färber83f7d432012-02-09 15:20:55 +0100139static void ds1338_register_types(void)
Paul Brook1dfe3942009-11-20 00:21:33 +0000140{
Anthony Liguori39bffca2011-12-07 21:34:16 -0600141 type_register_static(&ds1338_info);
Paul Brook1dfe3942009-11-20 00:21:33 +0000142}
143
Andreas Färber83f7d432012-02-09 15:20:55 +0100144type_init(ds1338_register_types)