diff options
Diffstat (limited to 'hw/rtc/goldfish_rtc.c')
| -rw-r--r-- | hw/rtc/goldfish_rtc.c | 285 |
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) |