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/**
* @file
*
* @ingroup lpc24xx
*
* @brief Clock driver configuration.
*/
/*
* Copyright (c) 2008
* 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.
*/
#define RTEMS_STATUS_CHECKS_USE_PRINTK
#include <rtems/status-checks.h>
#include <bsp.h>
#include <bsp/lpc24xx.h>
#include <bsp/irq.h>
#include <bsp/system-clocks.h>
/* This is defined in ../../../shared/clockdrv_shell.h */
rtems_isr Clock_isr( rtems_vector_number vector);
#define Clock_driver_support_at_tick() \
do { \
T0IR = TIR_MR0; \
} while (0)
static void lpc24xx_clock_handler_install( void)
{
rtems_status_code sc = RTEMS_SUCCESSFUL;
sc = rtems_interrupt_handler_install(
LPC24XX_IRQ_TIMER_0,
"Clock",
RTEMS_INTERRUPT_UNIQUE,
(rtems_interrupt_handler) Clock_isr,
NULL
);
RTEMS_CHECK_SC_VOID( sc, "Install clock interrupt handler");
}
static void lpc24xx_clock_initialize( void)
{
rtems_interrupt_level level;
uint64_t interval = ((uint64_t) lpc24xx_cclk()
* (uint64_t) rtems_configuration_get_microseconds_per_tick()) / 1000000;
/* Set timer pclk to cclk */
rtems_interrupt_disable( level);
PCONP = SET_FLAGS( PCONP, 0x02);
PCLKSEL0 = SET_FLAGS( PCLKSEL0, 0x04);
rtems_interrupt_enable( level);
/* Reset timer */
T0TCR = TCR_RST;
/* Clear interrupt flags */
T0IR = 0xff;
/* Set timer mode */
T0CCR = 0;
/* Timer is incremented every pclk tick */
T0PR = 0;
/* Set match registers */
T0MR0 = (uint32_t) interval;
T0MR1 = 0xdeadbeef;
T0MR2 = 0xdeadbeef;
T0MR3 = 0xdeadbeef;
/* Generate interrupt and reset counter on match with MR0 */
T0MCR = TMCR_MR0I | TMCR_MR0R;
/* No external match */
T0EMR = 0;
/* Enable timer */
T0TCR = TCR_EN;
}
static void lpc24xx_clock_cleanup( void)
{
rtems_status_code sc = RTEMS_SUCCESSFUL;
/* Disable timer */
T0TCR = 0;
/* Remove interrupt handler */
sc = rtems_interrupt_handler_remove(
LPC24XX_IRQ_TIMER_0,
(rtems_interrupt_handler) Clock_isr,
NULL
);
RTEMS_CHECK_SC_VOID( sc, "Remove clock interrupt handler");
}
static uint32_t lpc24xx_clock_nanoseconds_since_last_tick( void)
{
uint64_t clock = LPC24XX_CCLK;
uint32_t clicks = T0TC;
uint64_t ns = ((uint64_t) clicks * 1000000000) / clock;
return (uint32_t) ns;
}
#define Clock_driver_support_initialize_hardware() lpc24xx_clock_initialize()
#define Clock_driver_support_install_isr( isr, old_isr) lpc24xx_clock_handler_install()
#define Clock_driver_support_shutdown_hardware() lpc24xx_clock_cleanup()
#define Clock_driver_nanoseconds_since_last_tick lpc24xx_clock_nanoseconds_since_last_tick
/* Include shared source clock driver code */
#include "../../../../libbsp/shared/clockdrv_shell.h"
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