/* * ASPEED AST2400 Timer * * Andrew Jeffery * * Copyright (C) 2016 IBM Corp. * * This code is licensed under the GPL version 2 or later. See * the COPYING file in the top-level directory. */ #include "qemu/osdep.h" #include "qapi/error.h" #include "hw/irq.h" #include "hw/sysbus.h" #include "hw/timer/aspeed_timer.h" #include "migration/vmstate.h" #include "qemu/bitops.h" #include "qemu/timer.h" #include "qemu/log.h" #include "qemu/module.h" #include "hw/qdev-properties.h" #include "trace.h" #define TIMER_NR_REGS 4 #define TIMER_CTRL_BITS 4 #define TIMER_CTRL_MASK ((1 << TIMER_CTRL_BITS) - 1) #define TIMER_CLOCK_USE_EXT true #define TIMER_CLOCK_EXT_HZ 1000000 #define TIMER_CLOCK_USE_APB false #define TIMER_REG_STATUS 0 #define TIMER_REG_RELOAD 1 #define TIMER_REG_MATCH_FIRST 2 #define TIMER_REG_MATCH_SECOND 3 #define TIMER_FIRST_CAP_PULSE 4 enum timer_ctrl_op { op_enable = 0, op_external_clock, op_overflow_interrupt, op_pulse_enable }; /* * Minimum value of the reload register to filter out short period * timers which have a noticeable impact in emulation. 5us should be * enough, use 20us for "safety". */ #define TIMER_MIN_NS (20 * SCALE_US) /** * Avoid mutual references between AspeedTimerCtrlState and AspeedTimer * structs, as it's a waste of memory. The ptimer BH callback needs to know * whether a specific AspeedTimer is enabled, but this information is held in * AspeedTimerCtrlState. So, provide a helper to hoist ourselves from an * arbitrary AspeedTimer to AspeedTimerCtrlState. */ static inline AspeedTimerCtrlState *timer_to_ctrl(AspeedTimer *t) { const AspeedTimer (*timers)[] = (void *)t - (t->id * sizeof(*t)); return container_of(timers, AspeedTimerCtrlState, timers); } static inline bool timer_ctrl_status(AspeedTimer *t, enum timer_ctrl_op op) { return !!(timer_to_ctrl(t)->ctrl & BIT(t->id * TIMER_CTRL_BITS + op)); } static inline bool timer_enabled(AspeedTimer *t) { return timer_ctrl_status(t, op_enable); } static inline bool timer_overflow_interrupt(AspeedTimer *t) { return timer_ctrl_status(t, op_overflow_interrupt); } static inline bool timer_can_pulse(AspeedTimer *t) { return t->id >= TIMER_FIRST_CAP_PULSE; } static inline bool timer_external_clock(AspeedTimer *t) { return timer_ctrl_status(t, op_external_clock); } static inline uint32_t calculate_rate(struct AspeedTimer *t) { AspeedTimerCtrlState *s = timer_to_ctrl(t); return timer_external_clock(t) ? TIMER_CLOCK_EXT_HZ : aspeed_scu_get_apb_freq(s->scu); } static inline uint32_t calculate_ticks(struct AspeedTimer *t, uint64_t now_ns) { uint64_t delta_ns = now_ns - MIN(now_ns, t->start); uint32_t rate = calculate_rate(t); uint64_t ticks = muldiv64(delta_ns, rate, NANOSECONDS_PER_SECOND); return t->reload - MIN(t->reload, ticks); } static uint32_t calculate_min_ticks(AspeedTimer *t, uint32_t value) { uint32_t rate = calculate_rate(t); uint32_t min_ticks = muldiv64(TIMER_MIN_NS, rate, NANOSECONDS_PER_SECOND); return value < min_ticks ? min_ticks : value; } static inline uint64_t calculate_time(struct AspeedTimer *t, uint32_t ticks) { uint64_t delta_ns; uint64_t delta_ticks; delta_ticks = t->reload - MIN(t->reload, ticks); delta_ns = muldiv64(delta_ticks, NANOSECONDS_PER_SECOND, calculate_rate(t)); return t->start + delta_ns; } static inline uint32_t calculate_match(struct AspeedTimer *t, int i) { return t->match[i] < t->reload ? t->match[i] : 0; } static uint64_t calculate_next(struct AspeedTimer *t) { uint64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); uint64_t next; /* * We don't know the relationship between the values in the match * registers, so sort using MAX/MIN/zero. We sort in that order as * the timer counts down to zero. */ next = calculate_time(t, MAX(calculate_match(t, 0), calculate_match(t, 1))); if (now < next) { return next; } next = calculate_time(t, MIN(calculate_match(t, 0), calculate_match(t, 1))); if (now < next) { return next; } next = calculate_time(t, 0); if (now < next) { return next; } /* We've missed all deadlines, fire interrupt and try again */ timer_del(&t->timer); if (timer_overflow_interrupt(t)) { AspeedTimerCtrlState *s = timer_to_ctrl(t); t->level = !t->level; s->irq_sts |= BIT(t->id); qemu_set_irq(t->irq, t->level); } next = MAX(MAX(calculate_match(t, 0), calculate_match(t, 1)), 0); t->start = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); return calculate_time(t, next); } static void aspeed_timer_mod(AspeedTimer *t) { uint64_t next = calculate_next(t); if (next) { timer_mod(&t->timer, next); } } static void aspeed_timer_expire(void *opaque) { AspeedTimer *t = opaque; bool interrupt = false; uint32_t ticks; if (!timer_enabled(t)) { return; } ticks = calculate_ticks(t, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)); if (!ticks) { interrupt = timer_overflow_interrupt(t) || !t->match[0] || !t->match[1]; } else if (ticks <= MIN(t->match[0], t->match[1])) { interrupt = true; } else if (ticks <= MAX(t->match[0], t->match[1])) { interrupt = true; } if (interrupt) { AspeedTimerCtrlState *s = timer_to_ctrl(t); t->level = !t->level; s->irq_sts |= BIT(t->id); qemu_set_irq(t->irq, t->level); } aspeed_timer_mod(t); } static uint64_t aspeed_timer_get_value(AspeedTimer *t, int reg) { uint64_t value; switch (reg) { case TIMER_REG_STATUS: if (timer_enabled(t)) { value = calculate_ticks(t, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)); } else { value = t->reload; } break; case TIMER_REG_RELOAD: value = t->reload; break; case TIMER_REG_MATCH_FIRST: case TIMER_REG_MATCH_SECOND: value = t->match[reg - 2]; break; default: qemu_log_mask(LOG_UNIMP, "%s: Programming error: unexpected reg: %d\n", __func__, reg); value = 0; break; } return value; } static uint64_t aspeed_timer_read(void *opaque, hwaddr offset, unsigned size) { AspeedTimerCtrlState *s = opaque; const int reg = (offset & 0xf) / 4; uint64_t value; switch (offset) { case 0x30: /* Control Register */ value = s->ctrl; break; case 0x00 ... 0x2c: /* Timers 1 - 4 */ value = aspeed_timer_get_value(&s->timers[(offset >> 4)], reg); break; case 0x40 ... 0x8c: /* Timers 5 - 8 */ value = aspeed_timer_get_value(&s->timers[(offset >> 4) - 1], reg); break; default: value = ASPEED_TIMER_GET_CLASS(s)->read(s, offset); break; } trace_aspeed_timer_read(offset, size, value); return value; } static void aspeed_timer_set_value(AspeedTimerCtrlState *s, int timer, int reg, uint32_t value) { AspeedTimer *t; uint32_t old_reload; trace_aspeed_timer_set_value(timer, reg, value); t = &s->timers[timer]; switch (reg) { case TIMER_REG_RELOAD: old_reload = t->reload; t->reload = calculate_min_ticks(t, value); /* If the reload value was not previously set, or zero, and * the current value is valid, try to start the timer if it is * enabled. */ if (old_reload || !t->reload) { break; } case TIMER_REG_STATUS: if (timer_enabled(t)) { uint64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); int64_t delta = (int64_t) value - (int64_t) calculate_ticks(t, now); uint32_t rate = calculate_rate(t); if (delta >= 0) { t->start += muldiv64(delta, NANOSECONDS_PER_SECOND, rate); } else { t->start -= muldiv64(-delta, NANOSECONDS_PER_SECOND, rate); } aspeed_timer_mod(t); } break; case TIMER_REG_MATCH_FIRST: case TIMER_REG_MATCH_SECOND: t->match[reg - 2] = value; if (timer_enabled(t)) { aspeed_timer_mod(t); } break; default: qemu_log_mask(LOG_UNIMP, "%s: Programming error: unexpected reg: %d\n", __func__, reg); break; } } /* Control register operations are broken out into helpers that can be * explicitly called on aspeed_timer_reset(), but also from * aspeed_timer_ctrl_op(). */ static void aspeed_timer_ctrl_enable(AspeedTimer *t, bool enable) { trace_aspeed_timer_ctrl_enable(t->id, enable); if (enable) { t->start = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); aspeed_timer_mod(t); } else { timer_del(&t->timer); } } static void aspeed_timer_ctrl_external_clock(AspeedTimer *t, bool enable) { trace_aspeed_timer_ctrl_external_clock(t->id, enable); } static void aspeed_timer_ctrl_overflow_interrupt(AspeedTimer *t, bool enable) { trace_aspeed_timer_ctrl_overflow_interrupt(t->id, enable); } static void aspeed_timer_ctrl_pulse_enable(AspeedTimer *t, bool enable) { if (timer_can_pulse(t)) { trace_aspeed_timer_ctrl_pulse_enable(t->id, enable); } else { qemu_log_mask(LOG_GUEST_ERROR, "%s: Timer does not support pulse mode\n", __func__); } } /** * Given the actions are fixed in number and completely described in helper * functions, dispatch with a lookup table rather than manage control flow with * a switch statement. */ static void (*const ctrl_ops[])(AspeedTimer *, bool) = { [op_enable] = aspeed_timer_ctrl_enable, [op_external_clock] = aspeed_timer_ctrl_external_clock, [op_overflow_interrupt] = aspeed_timer_ctrl_overflow_interrupt, [op_pulse_enable] = aspeed_timer_ctrl_pulse_enable, }; /** * Conditionally affect changes chosen by a timer's control bit. * * The aspeed_timer_ctrl_op() interface is convenient for the * aspeed_timer_set_ctrl() function as the "no change" early exit can be * calculated for all operations, which cleans up the caller code. However the * interface isn't convenient for the reset function where we want to enter a * specific state without artificially constructing old and new values that * will fall through the change guard (and motivates extracting the actions * out to helper functions). * * @t: The timer to manipulate * @op: The type of operation to be performed * @old: The old state of the timer's control bits * @new: The incoming state for the timer's control bits */ static void aspeed_timer_ctrl_op(AspeedTimer *t, enum timer_ctrl_op op, uint8_t old, uint8_t new) { const uint8_t mask = BIT(op); const bool enable = !!(new & mask); const bool changed = ((old ^ new) & mask); if (!changed) { return; } ctrl_ops[op](t, enable); } static void aspeed_timer_set_ctrl(AspeedTimerCtrlState *s, uint32_t reg) { int i; int shift; uint8_t t_old, t_new; AspeedTimer *t; const uint8_t enable_mask = BIT(op_enable); /* Handle a dependency between the 'enable' and remaining three * configuration bits - i.e. if more than one bit in the control set has * changed, including the 'enable' bit, then we want either disable the * timer and perform configuration, or perform configuration and then * enable the timer */ for (i = 0; i < ASPEED_TIMER_NR_TIMERS; i++) { t = &s->timers[i]; shift = (i * TIMER_CTRL_BITS); t_old = (s->ctrl >> shift) & TIMER_CTRL_MASK; t_new = (reg >> shift) & TIMER_CTRL_MASK; /* If we are disabling, do so first */ if ((t_old & enable_mask) && !(t_new & enable_mask)) { aspeed_timer_ctrl_enable(t, false); } aspeed_timer_ctrl_op(t, op_external_clock, t_old, t_new); aspeed_timer_ctrl_op(t, op_overflow_interrupt, t_old, t_new); aspeed_timer_ctrl_op(t, op_pulse_enable, t_old, t_new); /* If we are enabling, do so last */ if (!(t_old & enable_mask) && (t_new & enable_mask)) { aspeed_timer_ctrl_enable(t, true); } } s->ctrl = reg; } static void aspeed_timer_set_ctrl2(AspeedTimerCtrlState *s, uint32_t value) { trace_aspeed_timer_set_ctrl2(value); } static void aspeed_timer_write(void *opaque, hwaddr offset, uint64_t value, unsigned size) { const uint32_t tv = (uint32_t)(value & 0xFFFFFFFF); const int reg = (offset & 0xf) / 4; AspeedTimerCtrlState *s = opaque; switch (offset) { /* Control Registers */ case 0x30: aspeed_timer_set_ctrl(s, tv); break; /* Timer Registers */ case 0x00 ... 0x2c: aspeed_timer_set_value(s, (offset >> TIMER_NR_REGS), reg, tv); break; case 0x40 ... 0x8c: aspeed_timer_set_value(s, (offset >> TIMER_NR_REGS) - 1, reg, tv); break; default: ASPEED_TIMER_GET_CLASS(s)->write(s, offset, value); break; } } static const MemoryRegionOps aspeed_timer_ops = { .read = aspeed_timer_read, .write = aspeed_timer_write, .endianness = DEVICE_LITTLE_ENDIAN, .valid.min_access_size = 4, .valid.max_access_size = 4, .valid.unaligned = false, }; static uint64_t aspeed_2400_timer_read(AspeedTimerCtrlState *s, hwaddr offset) { uint64_t value; switch (offset) { case 0x34: value = s->ctrl2; break; case 0x38: case 0x3C: default: qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, offset); value = 0; break; } return value; } static void aspeed_2400_timer_write(AspeedTimerCtrlState *s, hwaddr offset, uint64_t value) { const uint32_t tv = (uint32_t)(value & 0xFFFFFFFF); switch (offset) { case 0x34: aspeed_timer_set_ctrl2(s, tv); break; case 0x38: case 0x3C: default: qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, offset); break; } } static uint64_t aspeed_2500_timer_read(AspeedTimerCtrlState *s, hwaddr offset) { uint64_t value; switch (offset) { case 0x34: value = s->ctrl2; break; case 0x38: value = s->ctrl3 & BIT(0); break; case 0x3C: default: qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, offset); value = 0; break; } return value; } static void aspeed_2500_timer_write(AspeedTimerCtrlState *s, hwaddr offset, uint64_t value) { const uint32_t tv = (uint32_t)(value & 0xFFFFFFFF); uint8_t command; switch (offset) { case 0x34: aspeed_timer_set_ctrl2(s, tv); break; case 0x38: command = (value >> 1) & 0xFF; if (command == 0xAE) { s->ctrl3 = 0x1; } else if (command == 0xEA) { s->ctrl3 = 0x0; } break; case 0x3C: if (s->ctrl3 & BIT(0)) { aspeed_timer_set_ctrl(s, s->ctrl & ~tv); } break; default: qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, offset); break; } } static uint64_t aspeed_2600_timer_read(AspeedTimerCtrlState *s, hwaddr offset) { uint64_t value; switch (offset) { case 0x34: value = s->irq_sts; break; case 0x38: case 0x3C: default: qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, offset); value = 0; break; } return value; } static void aspeed_2600_timer_write(AspeedTimerCtrlState *s, hwaddr offset, uint64_t value) { const uint32_t tv = (uint32_t)(value & 0xFFFFFFFF); switch (offset) { case 0x34: s->irq_sts &= tv; break; case 0x3C: aspeed_timer_set_ctrl(s, s->ctrl & ~tv); break; case 0x38: default: qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, offset); break; } } static void aspeed_init_one_timer(AspeedTimerCtrlState *s, uint8_t id) { AspeedTimer *t = &s->timers[id]; t->id = id; timer_init_ns(&t->timer, QEMU_CLOCK_VIRTUAL, aspeed_timer_expire, t); } static void aspeed_timer_realize(DeviceState *dev, Error **errp) { int i; SysBusDevice *sbd = SYS_BUS_DEVICE(dev); AspeedTimerCtrlState *s = ASPEED_TIMER(dev); assert(s->scu); for (i = 0; i < ASPEED_TIMER_NR_TIMERS; i++) { aspeed_init_one_timer(s, i); sysbus_init_irq(sbd, &s->timers[i].irq); } memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_timer_ops, s, TYPE_ASPEED_TIMER, 0x1000); sysbus_init_mmio(sbd, &s->iomem); } static void aspeed_timer_reset(DeviceState *dev) { int i; AspeedTimerCtrlState *s = ASPEED_TIMER(dev); for (i = 0; i < ASPEED_TIMER_NR_TIMERS; i++) { AspeedTimer *t = &s->timers[i]; /* Explicitly call helpers to avoid any conditional behaviour through * aspeed_timer_set_ctrl(). */ aspeed_timer_ctrl_enable(t, false); aspeed_timer_ctrl_external_clock(t, TIMER_CLOCK_USE_APB); aspeed_timer_ctrl_overflow_interrupt(t, false); aspeed_timer_ctrl_pulse_enable(t, false); t->level = 0; t->reload = 0; t->match[0] = 0; t->match[1] = 0; } s->ctrl = 0; s->ctrl2 = 0; s->ctrl3 = 0; s->irq_sts = 0; } static const VMStateDescription vmstate_aspeed_timer = { .name = "aspeed.timer", .version_id = 2, .minimum_version_id = 2, .fields = (VMStateField[]) { VMSTATE_UINT8(id, AspeedTimer), VMSTATE_INT32(level, AspeedTimer), VMSTATE_TIMER(timer, AspeedTimer), VMSTATE_UINT32(reload, AspeedTimer), VMSTATE_UINT32_ARRAY(match, AspeedTimer, 2), VMSTATE_END_OF_LIST() } }; static const VMStateDescription vmstate_aspeed_timer_state = { .name = "aspeed.timerctrl", .version_id = 2, .minimum_version_id = 2, .fields = (VMStateField[]) { VMSTATE_UINT32(ctrl, AspeedTimerCtrlState), VMSTATE_UINT32(ctrl2, AspeedTimerCtrlState), VMSTATE_UINT32(ctrl3, AspeedTimerCtrlState), VMSTATE_UINT32(irq_sts, AspeedTimerCtrlState), VMSTATE_STRUCT_ARRAY(timers, AspeedTimerCtrlState, ASPEED_TIMER_NR_TIMERS, 1, vmstate_aspeed_timer, AspeedTimer), VMSTATE_END_OF_LIST() } }; static Property aspeed_timer_properties[] = { DEFINE_PROP_LINK("scu", AspeedTimerCtrlState, scu, TYPE_ASPEED_SCU, AspeedSCUState *), DEFINE_PROP_END_OF_LIST(), }; static void timer_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); dc->realize = aspeed_timer_realize; dc->reset = aspeed_timer_reset; dc->desc = "ASPEED Timer"; dc->vmsd = &vmstate_aspeed_timer_state; dc->props = aspeed_timer_properties; } static const TypeInfo aspeed_timer_info = { .name = TYPE_ASPEED_TIMER, .parent = TYPE_SYS_BUS_DEVICE, .instance_size = sizeof(AspeedTimerCtrlState), .class_init = timer_class_init, .class_size = sizeof(AspeedTimerClass), .abstract = true, }; static void aspeed_2400_timer_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); AspeedTimerClass *awc = ASPEED_TIMER_CLASS(klass); dc->desc = "ASPEED 2400 Timer"; awc->read = aspeed_2400_timer_read; awc->write = aspeed_2400_timer_write; } static const TypeInfo aspeed_2400_timer_info = { .name = TYPE_ASPEED_2400_TIMER, .parent = TYPE_ASPEED_TIMER, .class_init = aspeed_2400_timer_class_init, }; static void aspeed_2500_timer_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); AspeedTimerClass *awc = ASPEED_TIMER_CLASS(klass); dc->desc = "ASPEED 2500 Timer"; awc->read = aspeed_2500_timer_read; awc->write = aspeed_2500_timer_write; } static const TypeInfo aspeed_2500_timer_info = { .name = TYPE_ASPEED_2500_TIMER, .parent = TYPE_ASPEED_TIMER, .class_init = aspeed_2500_timer_class_init, }; static void aspeed_2600_timer_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); AspeedTimerClass *awc = ASPEED_TIMER_CLASS(klass); dc->desc = "ASPEED 2600 Timer"; awc->read = aspeed_2600_timer_read; awc->write = aspeed_2600_timer_write; } static const TypeInfo aspeed_2600_timer_info = { .name = TYPE_ASPEED_2600_TIMER, .parent = TYPE_ASPEED_TIMER, .class_init = aspeed_2600_timer_class_init, }; static void aspeed_timer_register_types(void) { type_register_static(&aspeed_timer_info); type_register_static(&aspeed_2400_timer_info); type_register_static(&aspeed_2500_timer_info); type_register_static(&aspeed_2600_timer_info); } type_init(aspeed_timer_register_types)