genode/repos/base-hw/src/core/spec/riscv/timer.cc

59 lines
1.2 KiB
C++

/*
* \brief Timer driver for core
* \author Sebastian Sumpf
* \date 2015-08-22
*/
/*
* Copyright (C) 2015-2017 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 <kernel/timer.h>
#include <hw/spec/riscv/machine_call.h>
using namespace Genode;
using namespace Kernel;
Board::Timer::Timer(unsigned)
{
/* enable timer interrupt */
enum { STIE = 0x20 };
asm volatile ("csrs sie, %0" : : "r"(STIE));
}
time_t Board::Timer::stime() const { return Hw::get_sys_timer(); }
void Timer::_start_one_shot(time_t const ticks)
{
_device.timeout = _device.stime() + ticks;
Hw::set_sys_timer(_device.timeout);
}
time_t Timer::ticks_to_us(time_t const ticks) const {
return ticks / Board::Timer::TICS_PER_US; }
time_t Timer::us_to_ticks(time_t const us) const {
return us * Board::Timer::TICS_PER_MS; }
time_t Timer::_max_value() const {
return 0xffffffff; }
time_t Timer::_duration() const
{
addr_t time = _device.stime();
return time < _device.timeout ? _device.timeout - time
: _last_timeout_duration + (time - _device.timeout);
}
unsigned Timer::interrupt_id() const { return 5; }