forked from Imagelibrary/rtems
126 lines
2.8 KiB
C
126 lines
2.8 KiB
C
/**
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* @file
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*
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* @ingroup lpc24xx
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*
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* @brief Clock driver configuration.
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*/
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/*
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* Copyright (c) 2008
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* Embedded Brains GmbH
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* Obere Lagerstr. 30
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* D-82178 Puchheim
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* Germany
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* rtems@embedded-brains.de
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*
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* The license and distribution terms for this file may be found in the file
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* LICENSE in this distribution or at http://www.rtems.com/license/LICENSE.
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*/
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#define RTEMS_STATUS_CHECKS_USE_PRINTK
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#include <rtems/status-checks.h>
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#include <bsp.h>
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#include <bsp/lpc24xx.h>
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#include <bsp/irq.h>
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#include <bsp/system-clocks.h>
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/* This is defined in ../../../shared/clockdrv_shell.c */
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rtems_isr Clock_isr( rtems_vector_number vector);
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#define Clock_driver_support_at_tick() \
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do { \
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T0IR = TIR_MR0; \
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} while (0)
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static void lpc24xx_clock_handler_install( void)
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{
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rtems_status_code sc = RTEMS_SUCCESSFUL;
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sc = rtems_interrupt_handler_install(
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LPC24XX_IRQ_TIMER_0,
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"Clock",
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RTEMS_INTERRUPT_UNIQUE,
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(rtems_interrupt_handler) Clock_isr,
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NULL
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);
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CHECK_SC_VOID( sc, "Install clock interrupt handler");
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}
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static void lpc24xx_clock_initialize( void)
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{
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rtems_interrupt_level level;
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uint64_t interval = ((uint64_t) lpc24xx_cclk()
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* (uint64_t) rtems_configuration_get_microseconds_per_tick()) / 1000000;
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/* Set timer pclk to cclk */
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rtems_interrupt_disable( level);
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SET_PCLKSEL0_PCLK_TIMER0( PCLKSEL0, 1);
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rtems_interrupt_enable( level);
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/* Reset timer */
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T0TCR = TCR_RST;
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/* Clear interrupt flags */
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T0IR = 0xff;
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/* Set timer mode */
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T0CCR = 0;
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/* Timer is incremented every pclk tick */
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T0PR = 0;
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/* Set match registers */
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T0MR0 = (uint32_t) interval;
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T0MR1 = 0xdeadbeef;
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T0MR2 = 0xdeadbeef;
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T0MR3 = 0xdeadbeef;
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/* Generate interrupt and reset counter on match with MR0 */
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T0MCR = TMCR_MR0I | TMCR_MR0R;
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/* No external match */
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T0EMR = 0;
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/* Enable timer */
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T0TCR = TCR_EN;
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}
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static void lpc24xx_clock_cleanup( void)
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{
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rtems_status_code sc = RTEMS_SUCCESSFUL;
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/* Disable timer */
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T0TCR = 0;
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/* Remove interrupt handler */
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sc = rtems_interrupt_handler_remove(
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LPC24XX_IRQ_TIMER_0,
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(rtems_interrupt_handler) Clock_isr,
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NULL
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);
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CHECK_SC_VOID( sc, "Remove clock interrupt handler");
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}
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static uint32_t lpc24xx_clock_nanoseconds_since_last_tick( void)
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{
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uint64_t clock = lpc24xx_cclk();
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uint32_t clicks = T0TC;
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uint64_t ns = ((uint64_t) clicks * 1000000000) / clock;
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return (uint32_t) ns;
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}
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#define Clock_driver_support_initialize_hardware() lpc24xx_clock_initialize()
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#define Clock_driver_support_install_isr( isr, old_isr) lpc24xx_clock_handler_install()
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#define Clock_driver_support_shutdown_hardware() lpc24xx_clock_cleanup()
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#define Clock_driver_nanoseconds_since_last_tick lpc24xx_clock_nanoseconds_since_last_tick
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/* Include shared source clock driver code */
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#include "../../../../libbsp/shared/clockdrv_shell.c"
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