| /* |
| * Copyright (c) 2016-2019 Nordic Semiconductor ASA |
| * Copyright (c) 2018 Intel Corporation |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #include <soc.h> |
| #include <drivers/clock_control.h> |
| #include <drivers/clock_control/nrf_clock_control.h> |
| #include <drivers/timer/system_timer.h> |
| #include <sys_clock.h> |
| #include <hal/nrf_timer.h> |
| #include <spinlock.h> |
| |
| #define TIMER NRF_TIMER0 |
| |
| #define COUNTER_MAX 0xffffffff |
| #define CYC_PER_TICK (sys_clock_hw_cycles_per_sec() \ |
| / CONFIG_SYS_CLOCK_TICKS_PER_SEC) |
| #define MAX_TICKS ((COUNTER_MAX - CYC_PER_TICK) / CYC_PER_TICK) |
| |
| static struct k_spinlock lock; |
| |
| static u32_t last_count; |
| |
| static u32_t counter_sub(u32_t a, u32_t b) |
| { |
| return (a - b) & COUNTER_MAX; |
| } |
| |
| static void set_comparator(u32_t cyc) |
| { |
| nrf_timer_cc_set(TIMER, 0, cyc & COUNTER_MAX); |
| } |
| |
| static u32_t counter(void) |
| { |
| nrf_timer_task_trigger(TIMER, nrf_timer_capture_task_get(1)); |
| |
| return nrf_timer_cc_get(TIMER, 1); |
| } |
| |
| void timer0_nrf_isr(void *arg) |
| { |
| ARG_UNUSED(arg); |
| TIMER->EVENTS_COMPARE[0] = 0; |
| |
| k_spinlock_key_t key = k_spin_lock(&lock); |
| u32_t t = counter(); |
| u32_t dticks = counter_sub(t, last_count) / CYC_PER_TICK; |
| |
| last_count += dticks * CYC_PER_TICK; |
| |
| if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) { |
| u32_t next = last_count + CYC_PER_TICK; |
| |
| /* As below: we're guaranteed to get an interrupt as |
| * long as it's set two or more cycles in the future |
| */ |
| if (counter_sub(next, t) < 3) { |
| next += CYC_PER_TICK; |
| } |
| set_comparator(next); |
| } |
| |
| k_spin_unlock(&lock, key); |
| z_clock_announce(IS_ENABLED(CONFIG_TICKLESS_KERNEL) ? dticks : 1); |
| } |
| |
| int z_clock_driver_init(struct device *device) |
| { |
| struct device *clock; |
| |
| ARG_UNUSED(device); |
| |
| clock = device_get_binding(DT_INST_0_NORDIC_NRF_CLOCK_LABEL "_16M"); |
| if (!clock) { |
| return -1; |
| } |
| |
| /* turn on clock in blocking mode. */ |
| clock_control_on(clock, (void *)1); |
| |
| nrf_timer_frequency_set(TIMER, NRF_TIMER_FREQ_1MHz); |
| nrf_timer_bit_width_set(TIMER, NRF_TIMER_BIT_WIDTH_32); |
| nrf_timer_cc_set(TIMER, 0, CYC_PER_TICK); |
| nrf_timer_int_enable(TIMER, TIMER_INTENSET_COMPARE0_Msk); |
| |
| /* Clear the event flag and possible pending interrupt */ |
| nrf_timer_event_clear(TIMER, NRF_TIMER_EVENT_COMPARE0); |
| NVIC_ClearPendingIRQ(TIMER0_IRQn); |
| |
| IRQ_CONNECT(TIMER0_IRQn, 1, timer0_nrf_isr, 0, 0); |
| irq_enable(TIMER0_IRQn); |
| |
| nrf_timer_task_trigger(TIMER, NRF_TIMER_TASK_CLEAR); |
| nrf_timer_task_trigger(TIMER, NRF_TIMER_TASK_START); |
| |
| if (!IS_ENABLED(TICKLESS_KERNEL)) { |
| set_comparator(counter() + CYC_PER_TICK); |
| } |
| |
| return 0; |
| } |
| |
| void z_clock_set_timeout(s32_t ticks, bool idle) |
| { |
| ARG_UNUSED(idle); |
| |
| #ifdef CONFIG_TICKLESS_KERNEL |
| ticks = (ticks == K_FOREVER) ? MAX_TICKS : ticks; |
| ticks = MAX(MIN(ticks - 1, (s32_t)MAX_TICKS), 0); |
| |
| k_spinlock_key_t key = k_spin_lock(&lock); |
| u32_t cyc, dt, t = counter(); |
| bool zli_fixup = IS_ENABLED(CONFIG_ZERO_LATENCY_IRQS); |
| |
| /* Round up to next tick boundary */ |
| cyc = ticks * CYC_PER_TICK + 1 + counter_sub(t, last_count); |
| cyc += (CYC_PER_TICK - 1); |
| cyc = (cyc / CYC_PER_TICK) * CYC_PER_TICK; |
| cyc += last_count; |
| |
| if (counter_sub(cyc, t) > 2) { |
| set_comparator(cyc); |
| } else { |
| set_comparator(cyc); |
| dt = counter_sub(cyc, counter()); |
| if (dt == 0 || dt > 0x7fffff) { |
| /* Missed it! */ |
| NVIC_SetPendingIRQ(TIMER0_IRQn); |
| if (IS_ENABLED(CONFIG_ZERO_LATENCY_IRQS)) { |
| zli_fixup = false; |
| } |
| } else if (dt == 1) { |
| /* Too soon, interrupt won't arrive. */ |
| set_comparator(cyc + 2); |
| } |
| /* Otherwise it was two cycles out, we're fine */ |
| } |
| |
| #ifdef CONFIG_ZERO_LATENCY_IRQS |
| /* Failsafe. ZLIs can preempt us even though interrupts are |
| * masked, blowing up the sensitive timing above. If the |
| * feature is enabled and we haven't recorded the presence of |
| * a pending interrupt then we need a final check (in a loop! |
| * because this too can be interrupted) to confirm that the |
| * comparator is still in the future. Don't bother being |
| * fancy with cycle counting here, just set an interrupt |
| * "soon" that we know will get the timer back to a known |
| * state. This handles (via some hairy modular expressions) |
| * the wraparound cases where we are preempted for as much as |
| * half the counter space. |
| */ |
| if (zli_fixup && counter_sub(cyc, counter()) <= 0x7fffff) { |
| while (counter_sub(cyc, counter() + 2) > 0x7fffff) { |
| cyc = counter() + 3; |
| set_comparator(cyc); |
| } |
| } |
| #endif |
| |
| k_spin_unlock(&lock, key); |
| #endif /* CONFIG_TICKLESS_KERNEL */ |
| } |
| |
| u32_t z_clock_elapsed(void) |
| { |
| if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) { |
| return 0; |
| } |
| |
| k_spinlock_key_t key = k_spin_lock(&lock); |
| u32_t ret = counter_sub(counter(), last_count) / CYC_PER_TICK; |
| |
| k_spin_unlock(&lock, key); |
| return ret; |
| } |
| |
| u32_t z_timer_cycle_get_32(void) |
| { |
| k_spinlock_key_t key = k_spin_lock(&lock); |
| u32_t ret = counter_sub(counter(), last_count) + last_count; |
| |
| k_spin_unlock(&lock, key); |
| return ret; |
| } |