hw: Move DS1338 device from hw/timer/ to hw/rtc/ subdirectory

The DS1338 is a Real Time Clock, not a timer.
Move it under the hw/rtc/ subdirectory.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20191003230404.19384-9-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

3 files changed, 246 insertions, 0 deletions

diff --git a/hw/rtc/Kconfig b/hw/rtc/Kconfig
index dff9d60946..45daa8d655 100644
--- a/hw/rtc/Kconfig
+++ b/hw/rtc/Kconfig
@@ -1,3 +1,7 @@
+config DS1338
+    bool
+    depends on I2C
+
 config M41T80
     bool
     depends on I2C
diff --git a/hw/rtc/Makefile.objs b/hw/rtc/Makefile.objs
index 810a38ee7b..b195863291 100644
--- a/hw/rtc/Makefile.objs
+++ b/hw/rtc/Makefile.objs
@@ -1,3 +1,4 @@
+common-obj-$(CONFIG_DS1338) += ds1338.o
 common-obj-$(CONFIG_M41T80) += m41t80.o
 common-obj-$(CONFIG_M48T59) += m48t59.o
 ifeq ($(CONFIG_ISA_BUS),y)
diff --git a/hw/rtc/ds1338.c b/hw/rtc/ds1338.c
new file mode 100644
index 0000000000..588a9ba9be
--- /dev/null
+++ b/hw/rtc/ds1338.c
@@ -0,0 +1,241 @@
+/*
+ * 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 "qemu/osdep.h"
+#include "qemu-common.h"
+#include "hw/i2c/i2c.h"
+#include "migration/vmstate.h"
+#include "qemu/bcd.h"
+#include "qemu/module.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 int 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;
+    }
+
+    return 0;
+}
+
+static uint8_t 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 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->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)