diff options
Diffstat (limited to 'hw/timer')
| -rw-r--r-- | hw/timer/Makefile.objs | 1 | ||||
| -rw-r--r-- | hw/timer/bcm2835_systmr.c | 163 | ||||
| -rw-r--r-- | hw/timer/trace-events | 5 |
3 files changed, 169 insertions, 0 deletions
diff --git a/hw/timer/Makefile.objs b/hw/timer/Makefile.objs index 123d92c969..696cda5905 100644 --- a/hw/timer/Makefile.objs +++ b/hw/timer/Makefile.objs @@ -47,3 +47,4 @@ common-obj-$(CONFIG_SUN4V_RTC) += sun4v-rtc.o common-obj-$(CONFIG_CMSDK_APB_TIMER) += cmsdk-apb-timer.o common-obj-$(CONFIG_CMSDK_APB_DUALTIMER) += cmsdk-apb-dualtimer.o common-obj-$(CONFIG_MSF2) += mss-timer.o +common-obj-$(CONFIG_RASPI) += bcm2835_systmr.o diff --git a/hw/timer/bcm2835_systmr.c b/hw/timer/bcm2835_systmr.c new file mode 100644 index 0000000000..3387a6214a --- /dev/null +++ b/hw/timer/bcm2835_systmr.c @@ -0,0 +1,163 @@ +/* + * BCM2835 SYS timer emulation + * + * Copyright (C) 2019 Philippe Mathieu-Daudé <f4bug@amsat.org> + * + * SPDX-License-Identifier: GPL-2.0-or-later + * + * Datasheet: BCM2835 ARM Peripherals (C6357-M-1398) + * https://www.raspberrypi.org/app/uploads/2012/02/BCM2835-ARM-Peripherals.pdf + * + * Only the free running 64-bit counter is implemented. + * The 4 COMPARE registers and the interruption are not implemented. + */ + +#include "qemu/osdep.h" +#include "qemu/log.h" +#include "qemu/timer.h" +#include "hw/timer/bcm2835_systmr.h" +#include "hw/registerfields.h" +#include "migration/vmstate.h" +#include "trace.h" + +REG32(CTRL_STATUS, 0x00) +REG32(COUNTER_LOW, 0x04) +REG32(COUNTER_HIGH, 0x08) +REG32(COMPARE0, 0x0c) +REG32(COMPARE1, 0x10) +REG32(COMPARE2, 0x14) +REG32(COMPARE3, 0x18) + +static void bcm2835_systmr_update_irq(BCM2835SystemTimerState *s) +{ + bool enable = !!s->reg.status; + + trace_bcm2835_systmr_irq(enable); + qemu_set_irq(s->irq, enable); +} + +static void bcm2835_systmr_update_compare(BCM2835SystemTimerState *s, + unsigned timer_index) +{ + /* TODO fow now, since neither Linux nor U-boot use these timers. */ + qemu_log_mask(LOG_UNIMP, "COMPARE register %u not implemented\n", + timer_index); +} + +static uint64_t bcm2835_systmr_read(void *opaque, hwaddr offset, + unsigned size) +{ + BCM2835SystemTimerState *s = BCM2835_SYSTIMER(opaque); + uint64_t r = 0; + + switch (offset) { + case A_CTRL_STATUS: + r = s->reg.status; + break; + case A_COMPARE0 ... A_COMPARE3: + r = s->reg.compare[(offset - A_COMPARE0) >> 2]; + break; + case A_COUNTER_LOW: + case A_COUNTER_HIGH: + /* Free running counter at 1MHz */ + r = qemu_clock_get_us(QEMU_CLOCK_VIRTUAL); + r >>= 8 * (offset - A_COUNTER_LOW); + r &= UINT32_MAX; + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, "%s: bad offset 0x%" HWADDR_PRIx "\n", + __func__, offset); + break; + } + trace_bcm2835_systmr_read(offset, r); + + return r; +} + +static void bcm2835_systmr_write(void *opaque, hwaddr offset, + uint64_t value, unsigned size) +{ + BCM2835SystemTimerState *s = BCM2835_SYSTIMER(opaque); + + trace_bcm2835_systmr_write(offset, value); + switch (offset) { + case A_CTRL_STATUS: + s->reg.status &= ~value; /* Ack */ + bcm2835_systmr_update_irq(s); + break; + case A_COMPARE0 ... A_COMPARE3: + s->reg.compare[(offset - A_COMPARE0) >> 2] = value; + bcm2835_systmr_update_compare(s, (offset - A_COMPARE0) >> 2); + break; + case A_COUNTER_LOW: + case A_COUNTER_HIGH: + qemu_log_mask(LOG_GUEST_ERROR, "%s: read-only ofs 0x%" HWADDR_PRIx "\n", + __func__, offset); + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, "%s: bad offset 0x%" HWADDR_PRIx "\n", + __func__, offset); + break; + } +} + +static const MemoryRegionOps bcm2835_systmr_ops = { + .read = bcm2835_systmr_read, + .write = bcm2835_systmr_write, + .endianness = DEVICE_LITTLE_ENDIAN, + .impl = { + .min_access_size = 4, + .max_access_size = 4, + }, +}; + +static void bcm2835_systmr_reset(DeviceState *dev) +{ + BCM2835SystemTimerState *s = BCM2835_SYSTIMER(dev); + + memset(&s->reg, 0, sizeof(s->reg)); +} + +static void bcm2835_systmr_realize(DeviceState *dev, Error **errp) +{ + BCM2835SystemTimerState *s = BCM2835_SYSTIMER(dev); + + memory_region_init_io(&s->iomem, OBJECT(dev), &bcm2835_systmr_ops, + s, "bcm2835-sys-timer", 0x20); + sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem); + sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq); +} + +static const VMStateDescription bcm2835_systmr_vmstate = { + .name = "bcm2835_sys_timer", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_UINT32(reg.status, BCM2835SystemTimerState), + VMSTATE_UINT32_ARRAY(reg.compare, BCM2835SystemTimerState, 4), + VMSTATE_END_OF_LIST() + } +}; + +static void bcm2835_systmr_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = bcm2835_systmr_realize; + dc->reset = bcm2835_systmr_reset; + dc->vmsd = &bcm2835_systmr_vmstate; +} + +static const TypeInfo bcm2835_systmr_info = { + .name = TYPE_BCM2835_SYSTIMER, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(BCM2835SystemTimerState), + .class_init = bcm2835_systmr_class_init, +}; + +static void bcm2835_systmr_register_types(void) +{ + type_register_static(&bcm2835_systmr_info); +} + +type_init(bcm2835_systmr_register_types); diff --git a/hw/timer/trace-events b/hw/timer/trace-events index db02a9142c..0aa399ac69 100644 --- a/hw/timer/trace-events +++ b/hw/timer/trace-events @@ -87,3 +87,8 @@ pl031_read(uint32_t addr, uint32_t value) "addr 0x%08x value 0x%08x" pl031_write(uint32_t addr, uint32_t value) "addr 0x%08x value 0x%08x" pl031_alarm_raised(void) "alarm raised" pl031_set_alarm(uint32_t ticks) "alarm set for %u ticks" + +# bcm2835_systmr.c +bcm2835_systmr_irq(bool enable) "timer irq state %u" +bcm2835_systmr_read(uint64_t offset, uint64_t data) "timer read: offset 0x%" PRIx64 " data 0x%" PRIx64 +bcm2835_systmr_write(uint64_t offset, uint64_t data) "timer write: offset 0x%" PRIx64 " data 0x%" PRIx64 |