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/*
* Copyright (c) 2013-2014 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
* 82178 Puchheim
* Germany
* <info@embedded-brains.de>
*
* 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 <bsp.h>
#include <bsp/fatal.h>
#include <bsp/irq.h>
#include <bsp/arm-a9mpcore-regs.h>
#include <bsp/arm-a9mpcore-clock.h>
#define A9MPCORE_GT ((volatile a9mpcore_gt *) BSP_ARM_A9MPCORE_GT_BASE)
static uint64_t a9mpcore_clock_last_tick_k;
static uint32_t a9mpcore_clock_last_tick_cmpvallower;
static uint32_t a9mpcore_clock_autoinc;
/* This is defined in clockdrv_shell.h */
void Clock_isr(rtems_irq_hdl_param arg);
__attribute__ ((weak)) uint32_t a9mpcore_clock_periphclk(void)
{
/* default to the BSP option. */
return BSP_ARM_A9MPCORE_PERIPHCLK;
}
static void a9mpcore_clock_at_tick(void)
{
volatile a9mpcore_gt *gt = A9MPCORE_GT;
/*
* FIXME: Now the _TOD_Get_with_nanoseconds() yields wrong values until
* _TOD_Tickle_ticks() managed to update the uptime. See also PR2180.
*/
a9mpcore_clock_last_tick_cmpvallower =
gt->cmpvallower - a9mpcore_clock_autoinc;
gt->irqst = A9MPCORE_GT_IRQST_EFLG;
}
static void a9mpcore_clock_handler_install(void)
{
rtems_status_code sc;
sc = rtems_interrupt_handler_install(
A9MPCORE_IRQ_GT,
"Clock",
RTEMS_INTERRUPT_UNIQUE,
(rtems_interrupt_handler) Clock_isr,
NULL
);
if (sc != RTEMS_SUCCESSFUL) {
bsp_fatal(BSP_ARM_A9MPCORE_FATAL_CLOCK_IRQ_INSTALL);
}
}
static uint64_t a9mpcore_clock_get_counter(volatile a9mpcore_gt *gt)
{
uint32_t cl;
uint32_t cu1;
uint32_t cu2;
do {
cu1 = gt->cntrupper;
cl = gt->cntrlower;
cu2 = gt->cntrupper;
} while (cu1 != cu2);
return ((uint64_t) cu2 << 32) | cl;
}
static void a9mpcore_clock_initialize(void)
{
volatile a9mpcore_gt *gt = A9MPCORE_GT;
uint64_t periphclk = a9mpcore_clock_periphclk();
uint64_t us_per_tick = rtems_configuration_get_microseconds_per_tick();
uint32_t interval = (uint32_t) ((periphclk * us_per_tick) / 1000000);
uint64_t cmpval;
gt->ctrl &= A9MPCORE_GT_CTRL_TMR_EN;
gt->irqst = A9MPCORE_GT_IRQST_EFLG;
cmpval = a9mpcore_clock_get_counter(gt);
cmpval += interval;
gt->cmpvallower = (uint32_t) cmpval;
gt->cmpvalupper = (uint32_t) (cmpval >> 32);
gt->autoinc = interval;
a9mpcore_clock_last_tick_k = (UINT64_C(1000000000) << 32) / periphclk;
a9mpcore_clock_last_tick_cmpvallower = (uint32_t) cmpval - interval;
a9mpcore_clock_autoinc = interval;
gt->ctrl = A9MPCORE_GT_CTRL_AUTOINC_EN
| A9MPCORE_GT_CTRL_IRQ_EN
| A9MPCORE_GT_CTRL_COMP_EN
| A9MPCORE_GT_CTRL_TMR_EN;
}
CPU_Counter_ticks _CPU_Counter_read(void)
{
volatile a9mpcore_gt *gt = A9MPCORE_GT;
return gt->cntrlower;
}
static void a9mpcore_clock_cleanup_isr(void *arg)
{
volatile a9mpcore_gt *gt = A9MPCORE_GT;
(void) arg;
gt->ctrl &= A9MPCORE_GT_CTRL_TMR_EN;
gt->irqst = A9MPCORE_GT_IRQST_EFLG;
}
static void a9mpcore_clock_cleanup(void)
{
rtems_status_code sc;
/*
* The relevant registers / bits of the global timer are banked and chances
* are on an SPM system, that we are executing on the wrong CPU to reset
* them. Thus we will have the actual cleanup done with the next clock tick.
* The ISR will execute on the right CPU for the cleanup.
*/
sc = rtems_interrupt_handler_install(
A9MPCORE_IRQ_GT,
"Clock",
RTEMS_INTERRUPT_REPLACE,
a9mpcore_clock_cleanup_isr,
NULL
);
if (sc != RTEMS_SUCCESSFUL) {
bsp_fatal(BSP_ARM_A9MPCORE_FATAL_CLOCK_IRQ_REMOVE);
}
}
static uint32_t a9mpcore_clock_nanoseconds_since_last_tick(void)
{
volatile a9mpcore_gt *gt = A9MPCORE_GT;
uint64_t k = a9mpcore_clock_last_tick_k;
uint32_t n = a9mpcore_clock_last_tick_cmpvallower;
uint32_t c = gt->cntrlower;
return (uint32_t) (((c - n) * k) >> 32);
}
#define Clock_driver_support_at_tick() \
a9mpcore_clock_at_tick()
#define Clock_driver_support_initialize_hardware() \
a9mpcore_clock_initialize()
#define Clock_driver_support_install_isr(isr, old_isr) \
do { \
a9mpcore_clock_handler_install(); \
old_isr = NULL; \
} while (0)
#define Clock_driver_support_shutdown_hardware() \
a9mpcore_clock_cleanup()
#define Clock_driver_nanoseconds_since_last_tick \
a9mpcore_clock_nanoseconds_since_last_tick
/* Include shared source clock driver code */
#include "../../shared/clockdrv_shell.h"
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