DS1338 RTC
Implement MAXIM SD1338 RTC+NVRAM.
Signed-off-by: Paul Brook <paul@codesourcery.com>
diff --git a/hw/ds1338.c b/hw/ds1338.c
new file mode 100644
index 0000000..6f5ae5e
--- /dev/null
+++ b/hw/ds1338.c
@@ -0,0 +1,132 @@
+/*
+ * MAXIM DS1338 I2C RTC+NVRAM
+ *
+ * Copyright (c) 2009 CodeSourcery.
+ * Written by Paul Brook
+ *
+ * This code is licenced under the GNU GPL v2.
+ */
+
+#include "i2c.h"
+
+typedef struct {
+ i2c_slave i2c;
+ time_t offset;
+ struct tm now;
+ uint8_t nvram[56];
+ int ptr;
+ int addr_byte;
+} DS1338State;
+
+static void ds1338_event(i2c_slave *i2c, enum i2c_event event)
+{
+ DS1338State *s = FROM_I2C_SLAVE(DS1338State, i2c);
+
+ switch (event) {
+ case I2C_START_RECV:
+ qemu_get_timedate(&s->now, s->offset);
+ s->nvram[0] = to_bcd(s->now.tm_sec);
+ s->nvram[1] = to_bcd(s->now.tm_min);
+ if (s->nvram[2] & 0x40) {
+ s->nvram[2] = (to_bcd((s->now.tm_hour % 12)) + 1) | 0x40;
+ if (s->now.tm_hour >= 12) {
+ s->nvram[2] |= 0x20;
+ }
+ } else {
+ s->nvram[2] = to_bcd(s->now.tm_hour);
+ }
+ s->nvram[3] = to_bcd(s->now.tm_wday) + 1;
+ s->nvram[4] = to_bcd(s->now.tm_mday);
+ s->nvram[5] = to_bcd(s->now.tm_mon) + 1;
+ s->nvram[6] = to_bcd(s->now.tm_year - 100);
+ break;
+ case I2C_START_SEND:
+ s->addr_byte = 1;
+ break;
+ default:
+ break;
+ }
+}
+
+static int ds1338_recv(i2c_slave *i2c)
+{
+ DS1338State *s = FROM_I2C_SLAVE(DS1338State, i2c);
+ uint8_t res;
+
+ res = s->nvram[s->ptr];
+ s->ptr = (s->ptr + 1) & 0xff;
+ return res;
+}
+
+static int ds1338_send(i2c_slave *i2c, uint8_t data)
+{
+ DS1338State *s = FROM_I2C_SLAVE(DS1338State, i2c);
+ if (s->addr_byte) {
+ s->ptr = data;
+ s->addr_byte = 0;
+ return 0;
+ }
+ s->nvram[s->ptr - 8] = data;
+ if (data < 8) {
+ qemu_get_timedate(&s->now, s->offset);
+ switch(data) {
+ case 0:
+ /* TODO: Implement CH (stop) bit. */
+ s->now.tm_sec = from_bcd(data & 0x7f);
+ break;
+ case 1:
+ s->now.tm_min = from_bcd(data & 0x7f);
+ break;
+ case 2:
+ if (data & 0x40) {
+ if (data & 0x20) {
+ data = from_bcd(data & 0x4f) + 11;
+ } else {
+ data = from_bcd(data & 0x1f) - 1;
+ }
+ } else {
+ data = from_bcd(data);
+ }
+ s->now.tm_hour = data;
+ break;
+ case 3:
+ s->now.tm_wday = from_bcd(data & 7) - 1;
+ break;
+ case 4:
+ s->now.tm_mday = from_bcd(data & 0x3f);
+ break;
+ case 5:
+ s->now.tm_mon = from_bcd(data & 0x1f) - 1;
+ case 6:
+ s->now.tm_year = from_bcd(data) + 100;
+ break;
+ case 7:
+ /* Control register. Currently ignored. */
+ break;
+ }
+ s->offset = qemu_timedate_diff(&s->now);
+ }
+ s->ptr = (s->ptr + 1) & 0xff;
+ return 0;
+}
+
+static int ds1338_init(i2c_slave *i2c)
+{
+ return 0;
+}
+
+static I2CSlaveInfo ds1338_info = {
+ .qdev.name = "ds1338",
+ .qdev.size = sizeof(DS1338State),
+ .init = ds1338_init,
+ .event = ds1338_event,
+ .recv = ds1338_recv,
+ .send = ds1338_send,
+};
+
+static void ds1338_register_devices(void)
+{
+ i2c_register_slave(&ds1338_info);
+}
+
+device_init(ds1338_register_devices)
