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/**
* @file
*
* @ingroup lpc_clock
*
* @brief Clock driver configuration.
*/
/*
* Copyright (c) 2009
* embedded brains GmbH
* Obere Lagerstr. 30
* D-82178 Puchheim
* Germany
* <rtems@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.com/license/LICENSE.
*/
#include <bsp/lpc-clock-config.h>
#include <bsp/lpc-timer.h>
/* This is defined in ../../../shared/clockdrv_shell.h */
rtems_isr Clock_isr(rtems_vector_number vector);
static volatile lpc_timer *const lpc_clock =
(volatile lpc_timer *) LPC_CLOCK_TIMER_BASE;
static void lpc_clock_at_tick(void)
{
lpc_clock->ir = LPC_TIMER_IR_MR0;
}
static void lpc_clock_handler_install(void)
{
rtems_status_code sc = RTEMS_SUCCESSFUL;
sc = rtems_interrupt_handler_install(
LPC_CLOCK_INTERRUPT,
"Clock",
RTEMS_INTERRUPT_UNIQUE,
(rtems_interrupt_handler) Clock_isr,
NULL
);
if (sc != RTEMS_SUCCESSFUL) {
rtems_fatal_error_occurred(0xdeadbeef);
}
}
static void lpc_clock_initialize(void)
{
uint64_t interval = ((uint64_t) LPC_CLOCK_REFERENCE
* (uint64_t) rtems_configuration_get_microseconds_per_tick()) / 1000000;
/* Enable module */
LPC_CLOCK_MODULE_ENABLE();
/* Reset timer */
lpc_clock->tcr = LPC_TIMER_TCR_RST;
/* Clear interrupt flags */
lpc_clock->ir = LPC_TIMER_IR_ALL;
/* Set timer mode */
lpc_clock->ccr = 0;
/* Timer is incremented every PERIPH_CLK tick */
lpc_clock->pr = 0;
/* Set match registers */
lpc_clock->mr0 = (uint32_t) interval;
/* Generate interrupt and reset counter on match with MR0 */
lpc_clock->mcr = LPC_TIMER_MCR_MR0_INTR | LPC_TIMER_MCR_MR0_RST;
/* No external match */
lpc_clock->emr = 0x0;
/* Enable timer */
lpc_clock->tcr = LPC_TIMER_TCR_EN;
}
static void lpc_clock_cleanup(void)
{
rtems_status_code sc = RTEMS_SUCCESSFUL;
/* Disable timer */
lpc_clock->tcr = 0x0;
/* Remove interrupt handler */
sc = rtems_interrupt_handler_remove(
LPC_CLOCK_INTERRUPT,
(rtems_interrupt_handler) Clock_isr,
NULL
);
if (sc != RTEMS_SUCCESSFUL) {
rtems_fatal_error_occurred(0xdeadbeef);
}
}
static uint32_t lpc_clock_nanoseconds_since_last_tick(void)
{
uint64_t clock = LPC_CLOCK_REFERENCE;
uint64_t clicks = lpc_clock->tc;
uint64_t ns = (clicks * 1000000000) / clock;
return (uint32_t) ns;
}
#define Clock_driver_support_at_tick() lpc_clock_at_tick()
#define Clock_driver_support_initialize_hardware() lpc_clock_initialize()
#define Clock_driver_support_install_isr(isr, old_isr) \
lpc_clock_handler_install()
#define Clock_driver_support_shutdown_hardware() lpc_clock_cleanup()
#define Clock_driver_nanoseconds_since_last_tick \
lpc_clock_nanoseconds_since_last_tick
/* Include shared source clock driver code */
#include "../../../../shared/clockdrv_shell.h"
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