static void mpc55xx_clock_initialize(void)
{
volatile struct EMIOS_CH_tag *regs = &EMIOS.CH [MPC55XX_CLOCK_EMIOS_CHANNEL];
union EMIOS_CCR_tag ccr = MPC55XX_ZERO_FLAGS;
union EMIOS_CSR_tag csr = MPC55XX_ZERO_FLAGS;
unsigned prescaler = mpc55xx_emios_global_prescaler();
uint64_t reference_clock = bsp_clock_speed;
uint64_t us_per_tick = rtems_configuration_get_microseconds_per_tick();
uint64_t interval = (reference_clock * us_per_tick) / 1000000;
/* Apply prescaler */
if (prescaler > 0) {
interval /= (uint64_t) prescaler;
} else {
bsp_fatal(MPC55XX_FATAL_CLOCK_EMIOS_PRESCALER);
}
/* Check interval */
if (interval == 0 || interval > MPC55XX_EMIOS_VALUE_MAX) {
bsp_fatal(MPC55XX_FATAL_CLOCK_EMIOS_INTERVAL);
}
/* Configure eMIOS channel */
/* Set channel in GPIO mode */
ccr.B.MODE = MPC55XX_EMIOS_MODE_GPIO_INPUT;
regs->CCR.R = ccr.R;
/* Clear status flags */
csr.B.OVR = 1;
csr.B.OVFL = 1;
csr.B.FLAG = 1;
regs->CSR.R = csr.R;
/* Set internal counter start value */
regs->CCNTR.R = 1;
/* Set timer period */
regs->CADR.R = (uint32_t) interval - 1;
/* Set control register */
#if MPC55XX_CHIP_FAMILY == 551
ccr.B.MODE = MPC55XX_EMIOS_MODE_MCB_UP_INT_CLK;
#else
ccr.B.MODE = MPC55XX_EMIOS_MODE_MC_UP_INT_CLK;
#endif
ccr.B.UCPREN = 1;
ccr.B.FEN = 1;
ccr.B.FREN = 1;
regs->CCR.R = ccr.R;
rtems_timecounter_simple_install(
&mpc55xx_tc,
reference_clock,
interval,
mpc55xx_tc_get_timecount
);
}
static void mpc55xx_clock_initialize(void)
{
volatile PIT_RTI_CHANNEL_tag *channel =
&PIT_RTI.CHANNEL [MPC55XX_CLOCK_PIT_CHANNEL];
uint64_t reference_clock = bsp_clock_speed;
uint64_t us_per_tick = rtems_configuration_get_microseconds_per_tick();
uint64_t interval = (reference_clock * us_per_tick) / 1000000;
PIT_RTI_PITMCR_32B_tag pitmcr = { .B = { .FRZ = 1 } };
PIT_RTI_TCTRL_32B_tag tctrl = { .B = { .TIE = 1, .TEN = 1 } };
PIT_RTI.PITMCR.R = pitmcr.R;
channel->LDVAL.R = interval;
channel->TCTRL.R = tctrl.R;
rtems_timecounter_simple_install(
&mpc55xx_tc,
reference_clock,
interval,
mpc55xx_tc_get_timecount
);
}
static void _ARMV7M_Systick_initialize(void)
{
volatile ARMV7M_DWT *dwt = _ARMV7M_DWT;
volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
#ifdef BSP_ARMV7M_SYSTICK_FREQUENCY
uint64_t freq = BSP_ARMV7M_SYSTICK_FREQUENCY;
#else
uint64_t freq = ARMV7M_SYSTICK_CALIB_TENMS_GET(systick->calib) * 100ULL;
#endif
uint64_t us_per_tick = rtems_configuration_get_microseconds_per_tick();
uint64_t interval = (freq * us_per_tick) / 1000000ULL;
uint32_t dwt_ctrl;
systick->rvr = (uint32_t) interval;
systick->cvr = 0;
systick->csr = ARMV7M_SYSTICK_CSR_ENABLE
| ARMV7M_SYSTICK_CSR_TICKINT
| ARMV7M_SYSTICK_CSR_CLKSOURCE;
dwt_ctrl = dwt->ctrl;
if ((dwt_ctrl & ARMV7M_DWT_CTRL_NOCYCCNT) == 0) {
dwt->ctrl = dwt_ctrl | ARMV7M_DWT_CTRL_CYCCNTENA;
_ARMV7M_TC.base.tc.tc_get_timecount = _ARMV7M_TC_dwt_get_timecount;
_ARMV7M_TC.base.tc.tc_counter_mask = 0xffffffff;
_ARMV7M_TC.base.tc.tc_frequency = freq;
_ARMV7M_TC.base.tc.tc_quality = RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER;
_ARMV7M_TC.tick = _ARMV7M_TC_dwt_tick;
rtems_timecounter_install(&_ARMV7M_TC.base.tc);
} else {
_ARMV7M_TC.tick = _ARMV7M_TC_systick_tick;
rtems_timecounter_simple_install(
&_ARMV7M_TC.base,
freq,
interval,
_ARMV7M_TC_systick_get_timecount
);
}
}
static void _ARMV7M_Systick_initialize(void)
{
volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
#ifdef BSP_ARMV7M_SYSTICK_FREQUENCY
uint64_t freq = BSP_ARMV7M_SYSTICK_FREQUENCY;
#else
uint64_t freq = ARMV7M_SYSTICK_CALIB_TENMS_GET(systick->calib) * 100ULL;
#endif
uint64_t us_per_tick = rtems_configuration_get_microseconds_per_tick();
uint64_t interval = (freq * us_per_tick) / 1000000ULL;
systick->rvr = (uint32_t) interval;
systick->cvr = 0;
systick->csr = ARMV7M_SYSTICK_CSR_ENABLE
| ARMV7M_SYSTICK_CSR_TICKINT
| ARMV7M_SYSTICK_CSR_CLKSOURCE;
rtems_timecounter_simple_install(
&_ARMV7M_TC,
freq,
interval,
_ARMV7M_TC_get_timecount
);
}
rtems_device_driver Clock_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
uint64_t frequency;
unsigned int tick_hz;
/*
* Take Timer that should be used as system timer.
*
*/
Clock_handle = tlib_open(Clock_timer);
if ( Clock_handle == NULL ) {
/* System Clock Timer not found */
return RTEMS_NOT_DEFINED;
}
/*
* Install Clock ISR before starting timer
*/
tlib_irq_register(Clock_handle, Clock_isr, NULL);
/* Set Timer Frequency to tick at Configured value. The Timer
* Frequency is set in multiples of the timer base frequency.
*
* In standard LEON3 designs the base frequency is is 1MHz, to
* save instructions undefine CLOCK_DRIVER_DONT_ASSUME_PRESCALER_1MHZ
* to avoid 64-bit calculation.
*/
#ifdef CLOCK_DRIVER_DONT_ASSUME_PRESCALER_1MHZ
{
uint64_t tmp;
tlib_get_freq(Clock_handle, &Clock_basefreq, NULL);
frequency = Clock_basefreq
tmp = frequency * (uint64_t)rtems_configuration_get_microseconds_per_tick();
tick_hz = tmp / 1000000;
}
#else
frequency = 1000000;
tick_hz = rtems_configuration_get_microseconds_per_tick();
#endif
tlib_set_freq(Clock_handle, tick_hz);
rtems_timecounter_simple_install(
&tlib_tc,
frequency,
tick_hz,
tlib_tc_get_timecount
);
/*
* IRQ and Frequency is setup, now we start the Timer. IRQ is still
* disabled globally during startup, so IRQ will hold for a while.
*/
tlib_start(Clock_handle, 0);
/*
* Register function called at system shutdown
*/
atexit( Clock_exit );
/*
* If we are counting ISRs per tick, then initialize the counter.
*/
#ifdef CLOCK_DRIVER_ISRS_PER_TICK
Clock_driver_isrs = CLOCK_DRIVER_ISRS_PER_TICK;
#endif
return RTEMS_SUCCESSFUL;
}
