genode/repos/base-hw/src/core/include/spec/cortex_a9/timer.h

105 lines
2.1 KiB
C++

/*
* \brief Timer driver for core
* \author Martin stein
* \date 2011-12-13
*/
/*
* Copyright (C) 2011-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _CORE__INCLUDE__SPEC__CORTEX_A9__TIMER_H_
#define _CORE__INCLUDE__SPEC__CORTEX_A9__TIMER_H_
/* base-hw includes */
#include <kernel/types.h>
/* Genode includes */
#include <util/mmio.h>
/* core includes */
#include <board.h>
namespace Genode { class Timer; }
/**
* Timer driver for core
*/
class Genode::Timer : public Mmio
{
private:
using time_t = Kernel::time_t;
enum {
TICS_PER_MS =
Board::CORTEX_A9_PRIVATE_TIMER_CLK /
Board::CORTEX_A9_PRIVATE_TIMER_DIV / 1000
};
/**
* Load value register
*/
struct Load : Register<0x0, 32> { };
/**
* Counter value register
*/
struct Counter : Register<0x4, 32> { };
/**
* Timer control register
*/
struct Control : Register<0x8, 32>
{
struct Timer_enable : Bitfield<0,1> { }; /* enable counting */
struct Irq_enable : Bitfield<2,1> { }; /* unmask interrupt */
struct Prescaler : Bitfield<8,8> { };
};
/**
* Timer interrupt status register
*/
struct Interrupt_status : Register<0xc, 32>
{
struct Event : Bitfield<0,1> { }; /* if counter hit zero */
};
public:
Timer();
/**
* Return kernel name of timer interrupt
*/
static unsigned interrupt_id(unsigned const) {
return Board::PRIVATE_TIMER_IRQ; }
/**
* Start single timeout run
*
* \param tics delay of timer interrupt
*/
void start_one_shot(time_t const tics, unsigned const);
time_t tics_to_us(time_t const tics) const {
return (tics / TICS_PER_MS) * 1000; }
time_t us_to_tics(time_t const us) const {
return (us / 1000) * TICS_PER_MS; }
/**
* Return current native timer value
*/
time_t value(unsigned const) { return read<Counter>(); }
time_t max_value() { return (Load::access_t)~0; }
};
namespace Kernel { using Genode::Timer; }
#endif /* _CORE__INCLUDE__SPEC__CORTEX_A9__TIMER_H_ */