The NPCM730 and NPCM750 SoCs have three timer modules each holding five timers and some shared registers (e.g. interrupt status).
Each timer runs at 25 MHz divided by a prescaler, and counts down from a configurable initial value to zero. When zero is reached, the interrupt flag for the timer is set, and the timer is disabled (one-shot mode) or reloaded from its initial value (periodic mode). This implementation is sufficient to boot a Linux kernel configured for NPCM750. Note that the kernel does not seem to actually turn on the interrupts. Reviewed-by: Tyrone Ting <kft...@nuvoton.com> Reviewed-by: Joel Stanley <j...@jms.id.au> Signed-off-by: Havard Skinnemoen <hskinnem...@google.com> --- hw/timer/Makefile.objs | 1 + hw/timer/npcm7xx_timer.c | 468 +++++++++++++++++++++++++++++++ hw/timer/trace-events | 5 + include/hw/timer/npcm7xx_timer.h | 96 +++++++ 4 files changed, 570 insertions(+) create mode 100644 hw/timer/npcm7xx_timer.c create mode 100644 include/hw/timer/npcm7xx_timer.h diff --git a/hw/timer/Makefile.objs b/hw/timer/Makefile.objs index a39f6ec0c2..84c484dda8 100644 --- a/hw/timer/Makefile.objs +++ b/hw/timer/Makefile.objs @@ -14,6 +14,7 @@ common-obj-$(CONFIG_IMX) += imx_epit.o common-obj-$(CONFIG_IMX) += imx_gpt.o common-obj-$(CONFIG_LM32) += lm32_timer.o common-obj-$(CONFIG_MILKYMIST) += milkymist-sysctl.o +common-obj-$(CONFIG_NPCM7XX) += npcm7xx_timer.o common-obj-$(CONFIG_NRF51_SOC) += nrf51_timer.o common-obj-$(CONFIG_ALTERA_TIMER) += altera_timer.o diff --git a/hw/timer/npcm7xx_timer.c b/hw/timer/npcm7xx_timer.c new file mode 100644 index 0000000000..b0a72aef75 --- /dev/null +++ b/hw/timer/npcm7xx_timer.c @@ -0,0 +1,468 @@ +/* + * Nuvoton NPCM7xx Timer Controller + * + * Copyright 2020 Google LLC + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that 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. + */ + +#include "qemu/osdep.h" + +#include "hw/irq.h" +#include "hw/timer/npcm7xx_timer.h" +#include "migration/vmstate.h" +#include "qemu/bitops.h" +#include "qemu/error-report.h" +#include "qemu/log.h" +#include "qemu/module.h" +#include "qemu/timer.h" +#include "qemu/units.h" +#include "trace.h" + +/* Register field definitions. */ +#define NPCM7XX_TCSR_CEN BIT(30) +#define NPCM7XX_TCSR_IE BIT(29) +#define NPCM7XX_TCSR_PERIODIC BIT(27) +#define NPCM7XX_TCSR_CRST BIT(26) +#define NPCM7XX_TCSR_CACT BIT(25) +#define NPCM7XX_TCSR_RSVD 0x21ffff00 +#define NPCM7XX_TCSR_PRESCALE_START 0 +#define NPCM7XX_TCSR_PRESCALE_LEN 8 + +/* The reference clock frequency is always 25 MHz. */ +#define NPCM7XX_TIMER_REF_HZ (25000000) + +/* Return the value by which to divide the reference clock rate. */ +static uint32_t npcm7xx_timer_prescaler(const NPCM7xxTimer *t) +{ + return extract32(t->tcsr, NPCM7XX_TCSR_PRESCALE_START, + NPCM7XX_TCSR_PRESCALE_LEN) + 1; +} + +/* Convert a timer cycle count to a time interval in nanoseconds. */ +static int64_t npcm7xx_timer_count_to_ns(NPCM7xxTimer *t, uint32_t count) +{ + int64_t ns = count; + + ns *= NANOSECONDS_PER_SECOND / NPCM7XX_TIMER_REF_HZ; + ns *= npcm7xx_timer_prescaler(t); + + return ns; +} + +/* Convert a time interval in nanoseconds to a timer cycle count. */ +static uint32_t npcm7xx_timer_ns_to_count(NPCM7xxTimer *t, int64_t ns) +{ + int64_t count; + + count = ns / (NANOSECONDS_PER_SECOND / NPCM7XX_TIMER_REF_HZ); + count /= npcm7xx_timer_prescaler(t); + + return count; +} + +/* + * Raise the interrupt line if there's a pending interrupt and interrupts are + * enabled for this timer. If not, lower it. + */ +static void npcm7xx_timer_check_interrupt(NPCM7xxTimer *t) +{ + NPCM7xxTimerCtrlState *tc = t->ctrl; + /* Find the array index of this timer. */ + int index = t - tc->timer; + + g_assert(index >= 0 && index < NPCM7XX_TIMERS_PER_CTRL); + + if ((t->tcsr & NPCM7XX_TCSR_IE) && (tc->tisr & BIT(index))) { + qemu_irq_raise(t->irq); + trace_npcm7xx_timer_irq(DEVICE(tc)->canonical_path, index, 1); + } else { + qemu_irq_lower(t->irq); + trace_npcm7xx_timer_irq(DEVICE(tc)->canonical_path, index, 0); + } +} + +/* Start or resume the timer. */ +static void npcm7xx_timer_start(NPCM7xxTimer *t) +{ + int64_t now; + + now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + t->expires_ns = now + t->remaining_ns; + timer_mod(&t->qtimer, t->expires_ns); +} + +/* + * Called when the counter reaches zero. Sets the interrupt flag, and either + * restarts or disables the timer. + */ +static void npcm7xx_timer_reached_zero(NPCM7xxTimer *t) +{ + NPCM7xxTimerCtrlState *tc = t->ctrl; + int index = t - tc->timer; + + g_assert(index >= 0 && index < NPCM7XX_TIMERS_PER_CTRL); + + tc->tisr |= BIT(index); + + if (t->tcsr & NPCM7XX_TCSR_PERIODIC) { + t->remaining_ns = npcm7xx_timer_count_to_ns(t, t->ticr); + if (t->tcsr & NPCM7XX_TCSR_CEN) { + npcm7xx_timer_start(t); + } + } else { + t->tcsr &= ~(NPCM7XX_TCSR_CEN | NPCM7XX_TCSR_CACT); + } + + npcm7xx_timer_check_interrupt(t); +} + +/* Stop counting. Record the time remaining so we can continue later. */ +static void npcm7xx_timer_pause(NPCM7xxTimer *t) +{ + int64_t now; + + timer_del(&t->qtimer); + now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + t->remaining_ns = t->expires_ns - now; + if (t->remaining_ns <= 0) { + npcm7xx_timer_reached_zero(t); + } +} + +/* + * Restart the timer from its initial value. If the timer was enabled and stays + * enabled, adjust the QEMU timer according to the new count. If the timer is + * transitioning from disabled to enabled, the caller is expected to start the + * timer later. + */ +static void npcm7xx_timer_restart(NPCM7xxTimer *t, uint32_t old_tcsr) +{ + t->remaining_ns = npcm7xx_timer_count_to_ns(t, t->ticr); + + if (old_tcsr & t->tcsr & NPCM7XX_TCSR_CEN) { + npcm7xx_timer_start(t); + } +} + +/* Register read and write handlers */ + +static void npcm7xx_timer_write_tcsr(NPCM7xxTimer *t, uint32_t new_tcsr) +{ + uint32_t old_tcsr = t->tcsr; + + if (new_tcsr & NPCM7XX_TCSR_RSVD) { + qemu_log_mask(LOG_GUEST_ERROR, "%s: reserved bits in 0x%08x ignored\n", + __func__, new_tcsr); + new_tcsr &= ~NPCM7XX_TCSR_RSVD; + } + if (new_tcsr & NPCM7XX_TCSR_CACT) { + qemu_log_mask(LOG_GUEST_ERROR, "%s: read-only bits in 0x%08x ignored\n", + __func__, new_tcsr); + new_tcsr &= ~NPCM7XX_TCSR_CACT; + } + + t->tcsr = (t->tcsr & NPCM7XX_TCSR_CACT) | new_tcsr; + + if ((old_tcsr ^ new_tcsr) & NPCM7XX_TCSR_IE) { + npcm7xx_timer_check_interrupt(t); + } + if (new_tcsr & NPCM7XX_TCSR_CRST) { + npcm7xx_timer_restart(t, old_tcsr); + t->tcsr &= ~NPCM7XX_TCSR_CRST; + } + if ((old_tcsr ^ new_tcsr) & NPCM7XX_TCSR_CEN) { + if (new_tcsr & NPCM7XX_TCSR_CEN) { + npcm7xx_timer_start(t); + } else { + npcm7xx_timer_pause(t); + } + } +} + +static void npcm7xx_timer_write_ticr(NPCM7xxTimer *t, uint32_t new_ticr) +{ + t->ticr = new_ticr; + + npcm7xx_timer_restart(t, t->tcsr); +} + +static uint32_t npcm7xx_timer_read_tdr(NPCM7xxTimer *t) +{ + if (t->tcsr & NPCM7XX_TCSR_CEN) { + int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + + return npcm7xx_timer_ns_to_count(t, t->expires_ns - now); + } + + return npcm7xx_timer_ns_to_count(t, t->remaining_ns); +} + +static uint64_t npcm7xx_timer_read(void *opaque, hwaddr offset, unsigned size) +{ + NPCM7xxTimerCtrlState *s = opaque; + uint64_t value = 0; + hwaddr reg; + + reg = offset / sizeof(uint32_t); + switch (reg) { + case NPCM7XX_TIMER_TCSR0: + value = s->timer[0].tcsr; + break; + case NPCM7XX_TIMER_TCSR1: + value = s->timer[1].tcsr; + break; + case NPCM7XX_TIMER_TCSR2: + value = s->timer[2].tcsr; + break; + case NPCM7XX_TIMER_TCSR3: + value = s->timer[3].tcsr; + break; + case NPCM7XX_TIMER_TCSR4: + value = s->timer[4].tcsr; + break; + + case NPCM7XX_TIMER_TICR0: + value = s->timer[0].ticr; + break; + case NPCM7XX_TIMER_TICR1: + value = s->timer[1].ticr; + break; + case NPCM7XX_TIMER_TICR2: + value = s->timer[2].ticr; + break; + case NPCM7XX_TIMER_TICR3: + value = s->timer[3].ticr; + break; + case NPCM7XX_TIMER_TICR4: + value = s->timer[4].ticr; + break; + + case NPCM7XX_TIMER_TDR0: + value = npcm7xx_timer_read_tdr(&s->timer[0]); + break; + case NPCM7XX_TIMER_TDR1: + value = npcm7xx_timer_read_tdr(&s->timer[1]); + break; + case NPCM7XX_TIMER_TDR2: + value = npcm7xx_timer_read_tdr(&s->timer[2]); + break; + case NPCM7XX_TIMER_TDR3: + value = npcm7xx_timer_read_tdr(&s->timer[3]); + break; + case NPCM7XX_TIMER_TDR4: + value = npcm7xx_timer_read_tdr(&s->timer[4]); + break; + + case NPCM7XX_TIMER_TISR: + value = s->tisr; + break; + + case NPCM7XX_TIMER_WTCR: + value = s->wtcr; + break; + + default: + qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid offset 0x%04x\n", + __func__, (unsigned int)offset); + break; + } + + trace_npcm7xx_timer_read(DEVICE(s)->canonical_path, offset, value); + + return value; +} + +static void npcm7xx_timer_write(void *opaque, hwaddr offset, + uint64_t v, unsigned size) +{ + uint32_t reg = offset / sizeof(uint32_t); + NPCM7xxTimerCtrlState *s = opaque; + uint32_t value = v; + + trace_npcm7xx_timer_write(DEVICE(s)->canonical_path, offset, value); + + switch (reg) { + case NPCM7XX_TIMER_TCSR0: + npcm7xx_timer_write_tcsr(&s->timer[0], value); + return; + case NPCM7XX_TIMER_TCSR1: + npcm7xx_timer_write_tcsr(&s->timer[1], value); + return; + case NPCM7XX_TIMER_TCSR2: + npcm7xx_timer_write_tcsr(&s->timer[2], value); + return; + case NPCM7XX_TIMER_TCSR3: + npcm7xx_timer_write_tcsr(&s->timer[3], value); + return; + case NPCM7XX_TIMER_TCSR4: + npcm7xx_timer_write_tcsr(&s->timer[4], value); + return; + + case NPCM7XX_TIMER_TICR0: + npcm7xx_timer_write_ticr(&s->timer[0], value); + return; + case NPCM7XX_TIMER_TICR1: + npcm7xx_timer_write_ticr(&s->timer[1], value); + return; + case NPCM7XX_TIMER_TICR2: + npcm7xx_timer_write_ticr(&s->timer[2], value); + return; + case NPCM7XX_TIMER_TICR3: + npcm7xx_timer_write_ticr(&s->timer[3], value); + return; + case NPCM7XX_TIMER_TICR4: + npcm7xx_timer_write_ticr(&s->timer[4], value); + return; + + case NPCM7XX_TIMER_TDR0: + case NPCM7XX_TIMER_TDR1: + case NPCM7XX_TIMER_TDR2: + case NPCM7XX_TIMER_TDR3: + case NPCM7XX_TIMER_TDR4: + qemu_log_mask(LOG_GUEST_ERROR, "%s: register @ 0x%04x is read-only\n", + __func__, (unsigned int)offset); + return; + + case NPCM7XX_TIMER_TISR: + s->tisr &= ~value; + return; + + case NPCM7XX_TIMER_WTCR: + qemu_log_mask(LOG_UNIMP, "%s: WTCR write not implemented: 0x%08x\n", + __func__, value); + return; + } + + qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid offset 0x%04x\n", + __func__, (unsigned int)offset); +} + +static const struct MemoryRegionOps npcm7xx_timer_ops = { + .read = npcm7xx_timer_read, + .write = npcm7xx_timer_write, + .endianness = DEVICE_LITTLE_ENDIAN, + .valid = { + .min_access_size = 4, + .max_access_size = 4, + .unaligned = false, + }, +}; + +/* Called when the QEMU timer expires. */ +static void npcm7xx_timer_expired(void *opaque) +{ + NPCM7xxTimer *t = opaque; + + if (t->tcsr & NPCM7XX_TCSR_CEN) { + npcm7xx_timer_reached_zero(t); + } +} + +static void npcm7xx_timer_enter_reset(Object *obj, ResetType type) +{ + NPCM7xxTimerCtrlState *s = NPCM7XX_TIMER(obj); + int i; + + for (i = 0; i < NPCM7XX_TIMERS_PER_CTRL; i++) { + NPCM7xxTimer *t = &s->timer[i]; + + timer_del(&t->qtimer); + t->expires_ns = 0; + t->remaining_ns = 0; + t->tcsr = 0x00000005; + t->ticr = 0x00000000; + } + + s->tisr = 0x00000000; + s->wtcr = 0x00000400; +} + +static void npcm7xx_timer_hold_reset(Object *obj) +{ + NPCM7xxTimerCtrlState *s = NPCM7XX_TIMER(obj); + int i; + + for (i = 0; i < NPCM7XX_TIMERS_PER_CTRL; i++) { + qemu_irq_lower(s->timer[i].irq); + } +} + +static void npcm7xx_timer_realize(DeviceState *dev, Error **errp) +{ + NPCM7xxTimerCtrlState *s = NPCM7XX_TIMER(dev); + SysBusDevice *sbd = &s->parent; + int i; + + for (i = 0; i < NPCM7XX_TIMERS_PER_CTRL; i++) { + NPCM7xxTimer *t = &s->timer[i]; + t->ctrl = s; + timer_init_ns(&t->qtimer, QEMU_CLOCK_VIRTUAL, npcm7xx_timer_expired, t); + sysbus_init_irq(sbd, &t->irq); + } + + memory_region_init_io(&s->iomem, OBJECT(s), &npcm7xx_timer_ops, s, + TYPE_NPCM7XX_TIMER, 4 * KiB); + sysbus_init_mmio(sbd, &s->iomem); +} + +static const VMStateDescription vmstate_npcm7xx_timer = { + .name = "npcm7xx-timer", + .version_id = 0, + .minimum_version_id = 0, + .fields = (VMStateField[]) { + VMSTATE_TIMER(qtimer, NPCM7xxTimer), + VMSTATE_INT64(expires_ns, NPCM7xxTimer), + VMSTATE_INT64(remaining_ns, NPCM7xxTimer), + VMSTATE_UINT32(tcsr, NPCM7xxTimer), + VMSTATE_UINT32(ticr, NPCM7xxTimer), + VMSTATE_END_OF_LIST(), + }, +}; + +static const VMStateDescription vmstate_npcm7xx_timer_ctrl = { + .name = "npcm7xx-timer-ctrl", + .version_id = 0, + .minimum_version_id = 0, + .fields = (VMStateField[]) { + VMSTATE_UINT32(tisr, NPCM7xxTimerCtrlState), + VMSTATE_UINT32(wtcr, NPCM7xxTimerCtrlState), + VMSTATE_STRUCT_ARRAY(timer, NPCM7xxTimerCtrlState, + NPCM7XX_TIMERS_PER_CTRL, 0, vmstate_npcm7xx_timer, + NPCM7xxTimer), + VMSTATE_END_OF_LIST(), + }, +}; + +static void npcm7xx_timer_class_init(ObjectClass *klass, void *data) +{ + ResettableClass *rc = RESETTABLE_CLASS(klass); + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->desc = "NPCM7xx Timer Controller"; + dc->realize = npcm7xx_timer_realize; + dc->vmsd = &vmstate_npcm7xx_timer_ctrl; + rc->phases.enter = npcm7xx_timer_enter_reset; + rc->phases.hold = npcm7xx_timer_hold_reset; +} + +static const TypeInfo npcm7xx_timer_info = { + .name = TYPE_NPCM7XX_TIMER, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(NPCM7xxTimerCtrlState), + .class_init = npcm7xx_timer_class_init, +}; + +static void npcm7xx_timer_register_type(void) +{ + type_register_static(&npcm7xx_timer_info); +} +type_init(npcm7xx_timer_register_type); diff --git a/hw/timer/trace-events b/hw/timer/trace-events index 866c9f546a..e2434ecf3f 100644 --- a/hw/timer/trace-events +++ b/hw/timer/trace-events @@ -66,6 +66,11 @@ cmsdk_apb_dualtimer_read(uint64_t offset, uint64_t data, unsigned size) "CMSDK A cmsdk_apb_dualtimer_write(uint64_t offset, uint64_t data, unsigned size) "CMSDK APB dualtimer write: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u" cmsdk_apb_dualtimer_reset(void) "CMSDK APB dualtimer: reset" +# npcm7xx_timer.c +npcm7xx_timer_read(const char *id, uint64_t offset, uint64_t value) " %s offset: 0x%04" PRIx64 " value 0x%08" PRIx64 +npcm7xx_timer_write(const char *id, uint64_t offset, uint64_t value) "%s offset: 0x%04" PRIx64 " value 0x%08" PRIx64 +npcm7xx_timer_irq(const char *id, int timer, int state) "%s timer %d state %d" + # nrf51_timer.c nrf51_timer_read(uint8_t timer_id, uint64_t addr, uint32_t value, unsigned size) "timer %u read addr 0x%" PRIx64 " data 0x%" PRIx32 " size %u" nrf51_timer_write(uint8_t timer_id, uint64_t addr, uint32_t value, unsigned size) "timer %u write addr 0x%" PRIx64 " data 0x%" PRIx32 " size %u" diff --git a/include/hw/timer/npcm7xx_timer.h b/include/hw/timer/npcm7xx_timer.h new file mode 100644 index 0000000000..94900a7877 --- /dev/null +++ b/include/hw/timer/npcm7xx_timer.h @@ -0,0 +1,96 @@ +/* + * Nuvoton NPCM7xx Timer Controller + * + * Copyright 2020 Google LLC + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that 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. + */ +#ifndef NPCM7XX_TIMER_H +#define NPCM7XX_TIMER_H + +#include "exec/memory.h" +#include "hw/sysbus.h" +#include "qemu/timer.h" + +/* Each Timer Module (TIM) instance holds five 25 MHz timers. */ +#define NPCM7XX_TIMERS_PER_CTRL (5) + +/** + * enum NPCM7xxTimerRegisters - 32-bit register indices. + */ +enum NPCM7xxTimerRegisters { + NPCM7XX_TIMER_TCSR0, + NPCM7XX_TIMER_TCSR1, + NPCM7XX_TIMER_TICR0, + NPCM7XX_TIMER_TICR1, + NPCM7XX_TIMER_TDR0, + NPCM7XX_TIMER_TDR1, + NPCM7XX_TIMER_TISR, + NPCM7XX_TIMER_WTCR, + NPCM7XX_TIMER_TCSR2, + NPCM7XX_TIMER_TCSR3, + NPCM7XX_TIMER_TICR2, + NPCM7XX_TIMER_TICR3, + NPCM7XX_TIMER_TDR2, + NPCM7XX_TIMER_TDR3, + NPCM7XX_TIMER_TCSR4 = 0x0040 / sizeof(uint32_t), + NPCM7XX_TIMER_TICR4 = 0x0048 / sizeof(uint32_t), + NPCM7XX_TIMER_TDR4 = 0x0050 / sizeof(uint32_t), + NPCM7XX_TIMER_NR_REGS, +}; + +typedef struct NPCM7xxTimerCtrlState NPCM7xxTimerCtrlState; + +/** + * struct NPCM7xxTimer - Individual timer state. + * @irq: GIC interrupt line to fire on expiration (if enabled). + * @qtimer: QEMU timer that notifies us on expiration. + * @expires_ns: Absolute virtual expiration time. + * @remaining_ns: Remaining time until expiration if timer is paused. + * @tcsr: The Timer Control and Status Register. + * @ticr: The Timer Initial Count Register. + */ +typedef struct NPCM7xxTimer { + NPCM7xxTimerCtrlState *ctrl; + + qemu_irq irq; + QEMUTimer qtimer; + int64_t expires_ns; + int64_t remaining_ns; + + uint32_t tcsr; + uint32_t ticr; +} NPCM7xxTimer; + +/** + * struct NPCM7xxTimerCtrlState - Timer Module device state. + * @parent: System bus device. + * @iomem: Memory region through which registers are accessed. + * @tisr: The Timer Interrupt Status Register. + * @wtcr: The Watchdog Timer Control Register. + * @timer: The five individual timers managed by this module. + */ +struct NPCM7xxTimerCtrlState { + SysBusDevice parent; + + MemoryRegion iomem; + + uint32_t tisr; + uint32_t wtcr; + + NPCM7xxTimer timer[NPCM7XX_TIMERS_PER_CTRL]; +}; + +#define TYPE_NPCM7XX_TIMER "npcm7xx-timer" +#define NPCM7XX_TIMER(obj) \ + OBJECT_CHECK(NPCM7xxTimerCtrlState, (obj), TYPE_NPCM7XX_TIMER) + +#endif /* NPCM7XX_TIMER_H */ -- 2.27.0.212.ge8ba1cc988-goog