--- /dev/null
+/*
+ * 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 "hw/i2c/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
+
+#define TYPE_DS1338 "ds1338"
+#define DS1338(obj) OBJECT_CHECK(DS1338State, (obj), TYPE_DS1338)
+
+typedef struct DS1338State {
+ I2CSlave parent_obj;
+
+ 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,
+ .fields = (VMStateField[]) {
+ VMSTATE_I2C_SLAVE(parent_obj, 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 = DS1338(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 = DS1338(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 = DS1338(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 = DS1338(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 = TYPE_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)
Code Review / kvmfornfv.git / blobdiff