31af206a8c
The kernel timer on RPI is able to measure time microseconds-precise. Howeer, due to a bug, we dropped precision during the ticks-to-time translation and return only milliseconds-precise time. Ref #2400
58 lines
1.3 KiB
C++
58 lines
1.3 KiB
C++
/*
|
|
* \brief Timer implementation specific to Rpi
|
|
* \author Norman Feske
|
|
* \author Stefan Kalkowski
|
|
* \author Martin Stein
|
|
* \date 2016-01-07
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2016-2017 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU Affero General Public License version 3.
|
|
*/
|
|
|
|
/* core includes */
|
|
#include <platform.h>
|
|
#include <kernel/timer.h>
|
|
|
|
using namespace Genode;
|
|
using namespace Kernel;
|
|
|
|
|
|
Timer_driver::Timer_driver(unsigned)
|
|
: Mmio(Platform::mmio_to_virt(Board::SYSTEM_TIMER_MMIO_BASE)) { }
|
|
|
|
|
|
void Timer::_start_one_shot(time_t const ticks)
|
|
{
|
|
_driver.write<Driver::Cs::M1>(1);
|
|
_driver.read<Driver::Cs>();
|
|
_driver.write<Driver::Clo>(0);
|
|
_driver.write<Driver::Cmp>(_driver.read<Driver::Clo>() + ticks);
|
|
}
|
|
|
|
|
|
time_t Timer::_ticks_to_us(time_t const ticks) const {
|
|
return ticks / Driver::TICS_PER_US; }
|
|
|
|
|
|
time_t Timer::us_to_ticks(time_t const us) const {
|
|
return us * Driver::TICS_PER_US; }
|
|
|
|
|
|
time_t Timer::_max_value() const {
|
|
return (Driver::Clo::access_t)~0; }
|
|
|
|
|
|
time_t Timer::_value()
|
|
{
|
|
Driver::Cmp::access_t const cmp = _driver.read<Driver::Cmp>();
|
|
Driver::Clo::access_t const clo = _driver.read<Driver::Clo>();
|
|
return cmp > clo ? cmp - clo : 0;
|
|
}
|
|
|
|
|
|
unsigned Timer::interrupt_id() const { return Board::SYSTEM_TIMER_IRQ; }
|