zephyr/drivers/timer/native_posix_timer.c

152 lines
3.6 KiB
C

/*
* Copyright (c) 2017 Oticon A/S
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* Driver for the timer model of the POSIX native_posix board
* It provides the interfaces required by the kernel and the sanity testcases
* It also provides a custom k_busy_wait() which can be used with the
* POSIX arch and InfClock SOC
*/
#include "zephyr/types.h"
#include "irq.h"
#include "device.h"
#include "drivers/system_timer.h"
#include "sys_clock.h"
#include "timer_model.h"
#include "soc.h"
#include "posix_trace.h"
static u64_t tick_period; /* System tick period in number of hw cycles */
static s64_t silent_ticks;
/**
* Return the current HW cycle counter
* (number of microseconds since boot in 32bits)
*/
u32_t _timer_cycle_get_32(void)
{
return hwm_get_time();
}
#ifdef CONFIG_TICKLESS_IDLE
/*
* Do not raise another ticker interrupt until the sys_ticks'th one
* e.g. if sys_ticks is 10, do not raise the next 9 ones
*
* if sys_ticks is K_FOREVER (or another negative number),
* we will effectively silence the tick interrupts forever
*/
void _timer_idle_enter(s32_t sys_ticks)
{
if (silent_ticks > 0) { /* LCOV_EXCL_BR_LINE */
/* LCOV_EXCL_START */
posix_print_warning("native timer: Re-entering idle mode with "
"%i ticks pending\n",
silent_ticks);
_timer_idle_exit();
/* LCOV_EXCL_STOP */
}
if (sys_ticks < 0) {
silent_ticks = INT64_MAX;
} else if (sys_ticks > 0) {
silent_ticks = sys_ticks - 1;
} else {
silent_ticks = 0;
}
hwtimer_set_silent_ticks(silent_ticks);
}
/*
* Exit from idle mode
*
* If we have been silent for a number of ticks, announce immediately to the
* kernel how many silent ticks have passed.
* If this is called due to the 1st non silent timer interrupt, sp_timer_isr()
* will be called right away, which will announce that last (non silent) one.
*
* Note that we do not assume this function is called before the interrupt is
* raised (the interrupt can handle it announcing all ticks)
*/
void _timer_idle_exit(void)
{
silent_ticks -= hwtimer_get_pending_silent_ticks();
if (silent_ticks > 0) {
_sys_idle_elapsed_ticks = silent_ticks;
_sys_clock_tick_announce();
}
silent_ticks = 0;
hwtimer_set_silent_ticks(0);
}
#endif
/**
* Interrupt handler for the timer interrupt
* Announce to the kernel that a tick has passed
*/
static void sp_timer_isr(void *arg)
{
ARG_UNUSED(arg);
_sys_idle_elapsed_ticks = silent_ticks + 1;
silent_ticks = 0;
_sys_clock_tick_announce();
}
/*
* Enable the hw timer, setting its tick period, and setup its interrupt
*/
int _sys_clock_driver_init(struct device *device)
{
ARG_UNUSED(device);
tick_period = 1000000ul / sys_clock_ticks_per_sec;
hwtimer_enable(tick_period);
IRQ_CONNECT(TIMER_TICK_IRQ, 1, sp_timer_isr, 0, 0);
irq_enable(TIMER_TICK_IRQ);
return 0;
}
#if defined(CONFIG_ARCH_HAS_CUSTOM_BUSY_WAIT)
/**
* Replacement to the kernel k_busy_wait()
* Will block this thread (and therefore the whole zephyr) during usec_to_wait
*
* Note that interrupts may be received in the meanwhile and that therefore this
* thread may loose context
*/
void k_busy_wait(u32_t usec_to_wait)
{
u64_t time_end = hwm_get_time() + usec_to_wait;
while (hwm_get_time() < time_end) {
/*There may be wakes due to other interrupts*/
hwtimer_wake_in_time(time_end);
posix_halt_cpu();
}
}
#endif
#if defined(CONFIG_SYSTEM_CLOCK_DISABLE)
/**
*
* @brief Stop announcing sys ticks into the kernel
*
* Disable the system ticks generation
*
* @return N/A
*/
void sys_clock_disable(void)
{
irq_disable(TIMER_TICK_IRQ);
hwtimer_set_silent_ticks(INT64_MAX);
}
#endif /* CONFIG_SYSTEM_CLOCK_DISABLE */