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/**
* @file
*
* @ingroup bsp_clock
*
* @brief or1k clock support.
*/
/*
* generic_or1k Clock driver
*
* COPYRIGHT (c) 2014-2015 Hesham ALMatary <heshamelmatary@gmail.com>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE
*/
#include <rtems.h>
#include <bsp.h>
#include <bsp/irq.h>
#include <bsp/generic_or1k.h>
#include <rtems/score/cpu.h>
#include <rtems/score/or1k-utility.h>
#include <rtems/timecounter.h>
/* The number of clock cycles before generating a tick timer interrupt. */
#define TTMR_NUM_OF_CLOCK_TICKS_INTERRUPT 0x09ED9
#define OR1K_CLOCK_CYCLE_TIME_NANOSECONDS 10
static struct timecounter or1ksim_tc;
/* CPU counter */
static CPU_Counter_ticks cpu_counter_ticks;
/* This prototype is added here to Avoid warnings */
void Clock_isr(void *arg);
static void generic_or1k_clock_at_tick(void)
{
uint32_t TTMR;
/* For TTMR register,
* The least significant 28 bits are the number of clock cycles
* before generating a tick timer interrupt. While the most
* significant 4 bits are used for mode configuration, tick timer
* interrupt enable and pending interrupts status.
*/
TTMR = (CPU_OR1K_SPR_TTMR_MODE_RESTART | CPU_OR1K_SPR_TTMR_IE |
(TTMR_NUM_OF_CLOCK_TICKS_INTERRUPT & CPU_OR1K_SPR_TTMR_TP_MASK)
) & ~(CPU_OR1K_SPR_TTMR_IP);
_OR1K_mtspr(CPU_OR1K_SPR_TTMR, TTMR);
_OR1K_mtspr(CPU_OR1K_SPR_TTCR, 0);
cpu_counter_ticks += TTMR_NUM_OF_CLOCK_TICKS_INTERRUPT;
}
static void generic_or1k_clock_handler_install(proc_ptr new_isr)
{
rtems_status_code sc = RTEMS_SUCCESSFUL;
_CPU_ISR_install_vector(OR1K_EXCEPTION_TICK_TIMER,
new_isr,
NULL);
if (sc != RTEMS_SUCCESSFUL) {
rtems_fatal_error_occurred(0xdeadbeef);
}
}
static uint32_t or1ksim_get_timecount(struct timecounter *tc)
{
uint32_t ticks_since_last_timer_interrupt;
ticks_since_last_timer_interrupt = _OR1K_mfspr(CPU_OR1K_SPR_TTCR);
return cpu_counter_ticks + ticks_since_last_timer_interrupt;
}
CPU_Counter_ticks _CPU_Counter_read(void)
{
return or1ksim_get_timecount(NULL);
}
static void generic_or1k_clock_initialize(void)
{
uint64_t frequency = (1000000000 / OR1K_CLOCK_CYCLE_TIME_NANOSECONDS);
uint32_t TTMR;
/* For TTMR register,
* The least significant 28 bits are the number of clock cycles
* before generating a tick timer interrupt. While the most
* significant 4 bits are used for mode configuration, tick timer
* interrupt enable and pending interrupts status.
*/
/* FIXME: Long interval should pass since initializing the tick timer
* registers fires exceptions dispite interrupts has not been enabled yet.
*/
TTMR = (CPU_OR1K_SPR_TTMR_MODE_RESTART | CPU_OR1K_SPR_TTMR_IE |
(0xFFED9 & CPU_OR1K_SPR_TTMR_TP_MASK)
) & ~(CPU_OR1K_SPR_TTMR_IP);
_OR1K_mtspr(CPU_OR1K_SPR_TTMR, TTMR);
_OR1K_mtspr(CPU_OR1K_SPR_TTCR, 0);
/* Initialize timecounter */
or1ksim_tc.tc_get_timecount = or1ksim_get_timecount;
or1ksim_tc.tc_counter_mask = 0xffffffff;
or1ksim_tc.tc_frequency = frequency;
or1ksim_tc.tc_quality = RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER;
rtems_timecounter_install(&or1ksim_tc);
}
CPU_Counter_ticks _CPU_Counter_difference(
CPU_Counter_ticks second,
CPU_Counter_ticks first
)
{
return second - first;
}
#define Clock_driver_support_at_tick() generic_or1k_clock_at_tick()
#define Clock_driver_support_initialize_hardware() generic_or1k_clock_initialize()
#define Clock_driver_support_install_isr(isr) \
generic_or1k_clock_handler_install(isr)
#include "../../../shared/dev/clock/clockimpl.h"
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