aboutsummaryrefslogtreecommitdiff
path: root/hw/rtc/goldfish_rtc.c
diff options
context:
space:
mode:
Diffstat (limited to 'hw/rtc/goldfish_rtc.c')
-rw-r--r--hw/rtc/goldfish_rtc.c285
1 files changed, 285 insertions, 0 deletions
diff --git a/hw/rtc/goldfish_rtc.c b/hw/rtc/goldfish_rtc.c
new file mode 100644
index 0000000000..01e9d2b083
--- /dev/null
+++ b/hw/rtc/goldfish_rtc.c
@@ -0,0 +1,285 @@
+/*
+ * Goldfish virtual platform RTC
+ *
+ * Copyright (C) 2019 Western Digital Corporation or its affiliates.
+ *
+ * For more details on Google Goldfish virtual platform refer:
+ * https://android.googlesource.com/platform/external/qemu/+/refs/heads/emu-2.0-release/docs/GOLDFISH-VIRTUAL-HARDWARE.TXT
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "hw/rtc/goldfish_rtc.h"
+#include "migration/vmstate.h"
+#include "hw/irq.h"
+#include "hw/qdev-properties.h"
+#include "hw/sysbus.h"
+#include "qemu/bitops.h"
+#include "qemu/timer.h"
+#include "sysemu/sysemu.h"
+#include "qemu/cutils.h"
+#include "qemu/log.h"
+
+#include "trace.h"
+
+#define RTC_TIME_LOW 0x00
+#define RTC_TIME_HIGH 0x04
+#define RTC_ALARM_LOW 0x08
+#define RTC_ALARM_HIGH 0x0c
+#define RTC_IRQ_ENABLED 0x10
+#define RTC_CLEAR_ALARM 0x14
+#define RTC_ALARM_STATUS 0x18
+#define RTC_CLEAR_INTERRUPT 0x1c
+
+static void goldfish_rtc_update(GoldfishRTCState *s)
+{
+ qemu_set_irq(s->irq, (s->irq_pending & s->irq_enabled) ? 1 : 0);
+}
+
+static void goldfish_rtc_interrupt(void *opaque)
+{
+ GoldfishRTCState *s = (GoldfishRTCState *)opaque;
+
+ s->alarm_running = 0;
+ s->irq_pending = 1;
+ goldfish_rtc_update(s);
+}
+
+static uint64_t goldfish_rtc_get_count(GoldfishRTCState *s)
+{
+ return s->tick_offset + (uint64_t)qemu_clock_get_ns(rtc_clock);
+}
+
+static void goldfish_rtc_clear_alarm(GoldfishRTCState *s)
+{
+ timer_del(s->timer);
+ s->alarm_running = 0;
+}
+
+static void goldfish_rtc_set_alarm(GoldfishRTCState *s)
+{
+ uint64_t ticks = goldfish_rtc_get_count(s);
+ uint64_t event = s->alarm_next;
+
+ if (event <= ticks) {
+ goldfish_rtc_clear_alarm(s);
+ goldfish_rtc_interrupt(s);
+ } else {
+ /*
+ * We should be setting timer expiry to:
+ * qemu_clock_get_ns(rtc_clock) + (event - ticks)
+ * but this is equivalent to:
+ * event - s->tick_offset
+ */
+ timer_mod(s->timer, event - s->tick_offset);
+ s->alarm_running = 1;
+ }
+}
+
+static uint64_t goldfish_rtc_read(void *opaque, hwaddr offset,
+ unsigned size)
+{
+ GoldfishRTCState *s = opaque;
+ uint64_t r = 0;
+
+ switch (offset) {
+ case RTC_TIME_LOW:
+ r = goldfish_rtc_get_count(s) & 0xffffffff;
+ break;
+ case RTC_TIME_HIGH:
+ r = goldfish_rtc_get_count(s) >> 32;
+ break;
+ case RTC_ALARM_LOW:
+ r = s->alarm_next & 0xffffffff;
+ break;
+ case RTC_ALARM_HIGH:
+ r = s->alarm_next >> 32;
+ break;
+ case RTC_IRQ_ENABLED:
+ r = s->irq_enabled;
+ break;
+ case RTC_ALARM_STATUS:
+ r = s->alarm_running;
+ break;
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: offset 0x%x is UNIMP.\n", __func__, (uint32_t)offset);
+ break;
+ }
+
+ trace_goldfish_rtc_read(offset, r);
+
+ return r;
+}
+
+static void goldfish_rtc_write(void *opaque, hwaddr offset,
+ uint64_t value, unsigned size)
+{
+ GoldfishRTCState *s = opaque;
+ uint64_t current_tick, new_tick;
+
+ switch (offset) {
+ case RTC_TIME_LOW:
+ current_tick = goldfish_rtc_get_count(s);
+ new_tick = deposit64(current_tick, 0, 32, value);
+ s->tick_offset += new_tick - current_tick;
+ break;
+ case RTC_TIME_HIGH:
+ current_tick = goldfish_rtc_get_count(s);
+ new_tick = deposit64(current_tick, 32, 32, value);
+ s->tick_offset += new_tick - current_tick;
+ break;
+ case RTC_ALARM_LOW:
+ s->alarm_next = deposit64(s->alarm_next, 0, 32, value);
+ goldfish_rtc_set_alarm(s);
+ break;
+ case RTC_ALARM_HIGH:
+ s->alarm_next = deposit64(s->alarm_next, 32, 32, value);
+ break;
+ case RTC_IRQ_ENABLED:
+ s->irq_enabled = (uint32_t)(value & 0x1);
+ goldfish_rtc_update(s);
+ break;
+ case RTC_CLEAR_ALARM:
+ goldfish_rtc_clear_alarm(s);
+ break;
+ case RTC_CLEAR_INTERRUPT:
+ s->irq_pending = 0;
+ goldfish_rtc_update(s);
+ break;
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: offset 0x%x is UNIMP.\n", __func__, (uint32_t)offset);
+ break;
+ }
+
+ trace_goldfish_rtc_write(offset, value);
+}
+
+static int goldfish_rtc_pre_save(void *opaque)
+{
+ uint64_t delta;
+ GoldfishRTCState *s = opaque;
+
+ /*
+ * We want to migrate this offset, which sounds straightforward.
+ * Unfortunately, we cannot directly pass tick_offset because
+ * rtc_clock on destination Host might not be same source Host.
+ *
+ * To tackle, this we pass tick_offset relative to vm_clock from
+ * source Host and make it relative to rtc_clock at destination Host.
+ */
+ delta = qemu_clock_get_ns(rtc_clock) -
+ qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+ s->tick_offset_vmstate = s->tick_offset + delta;
+
+ return 0;
+}
+
+static int goldfish_rtc_post_load(void *opaque, int version_id)
+{
+ uint64_t delta;
+ GoldfishRTCState *s = opaque;
+
+ /*
+ * We extract tick_offset from tick_offset_vmstate by doing
+ * reverse math compared to pre_save() function.
+ */
+ delta = qemu_clock_get_ns(rtc_clock) -
+ qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+ s->tick_offset = s->tick_offset_vmstate - delta;
+
+ return 0;
+}
+
+static const MemoryRegionOps goldfish_rtc_ops = {
+ .read = goldfish_rtc_read,
+ .write = goldfish_rtc_write,
+ .endianness = DEVICE_LITTLE_ENDIAN,
+ .valid = {
+ .min_access_size = 4,
+ .max_access_size = 4
+ }
+};
+
+static const VMStateDescription goldfish_rtc_vmstate = {
+ .name = TYPE_GOLDFISH_RTC,
+ .version_id = 1,
+ .pre_save = goldfish_rtc_pre_save,
+ .post_load = goldfish_rtc_post_load,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT64(tick_offset_vmstate, GoldfishRTCState),
+ VMSTATE_UINT64(alarm_next, GoldfishRTCState),
+ VMSTATE_UINT32(alarm_running, GoldfishRTCState),
+ VMSTATE_UINT32(irq_pending, GoldfishRTCState),
+ VMSTATE_UINT32(irq_enabled, GoldfishRTCState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static void goldfish_rtc_reset(DeviceState *dev)
+{
+ GoldfishRTCState *s = GOLDFISH_RTC(dev);
+ struct tm tm;
+
+ timer_del(s->timer);
+
+ qemu_get_timedate(&tm, 0);
+ s->tick_offset = mktimegm(&tm);
+ s->tick_offset *= NANOSECONDS_PER_SECOND;
+ s->tick_offset -= qemu_clock_get_ns(rtc_clock);
+ s->tick_offset_vmstate = 0;
+ s->alarm_next = 0;
+ s->alarm_running = 0;
+ s->irq_pending = 0;
+ s->irq_enabled = 0;
+}
+
+static void goldfish_rtc_realize(DeviceState *d, Error **errp)
+{
+ SysBusDevice *dev = SYS_BUS_DEVICE(d);
+ GoldfishRTCState *s = GOLDFISH_RTC(d);
+
+ memory_region_init_io(&s->iomem, OBJECT(s), &goldfish_rtc_ops, s,
+ "goldfish_rtc", 0x24);
+ sysbus_init_mmio(dev, &s->iomem);
+
+ sysbus_init_irq(dev, &s->irq);
+
+ s->timer = timer_new_ns(rtc_clock, goldfish_rtc_interrupt, s);
+}
+
+static void goldfish_rtc_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+
+ dc->realize = goldfish_rtc_realize;
+ dc->reset = goldfish_rtc_reset;
+ dc->vmsd = &goldfish_rtc_vmstate;
+}
+
+static const TypeInfo goldfish_rtc_info = {
+ .name = TYPE_GOLDFISH_RTC,
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(GoldfishRTCState),
+ .class_init = goldfish_rtc_class_init,
+};
+
+static void goldfish_rtc_register_types(void)
+{
+ type_register_static(&goldfish_rtc_info);
+}
+
+type_init(goldfish_rtc_register_types)
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-20 18:38:38 +0000