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/**
* @file
*
* @ingroup bsp_clock
*
* @brief Raspberry Pi clock support.
*/
/*
* BCM2835 Clock driver
*
* Copyright (c) 2013 Alan Cudmore
*
* 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 <rtems.h>
#include <bsp.h>
#include <bsp/irq.h>
#include <bsp/raspberrypi.h>
/* This is defined in ../../../shared/clockdrv_shell.h */
void Clock_isr(rtems_irq_hdl_param arg);
static void raspberrypi_clock_at_tick(void)
{
BCM2835_REG(BCM2835_TIMER_CLI) = 0;
}
static void raspberrypi_clock_handler_install(void)
{
rtems_status_code sc = RTEMS_SUCCESSFUL;
sc = rtems_interrupt_handler_install(
BCM2835_IRQ_ID_TIMER_0,
"Clock",
RTEMS_INTERRUPT_UNIQUE,
(rtems_interrupt_handler) Clock_isr,
NULL
);
if (sc != RTEMS_SUCCESSFUL) {
rtems_fatal_error_occurred(0xdeadbeef);
}
}
static void raspberrypi_clock_initialize(void)
{
BCM2835_REG(BCM2835_TIMER_CTL) = 0x003E0000;
BCM2835_REG(BCM2835_TIMER_LOD) = 10000 - 1;
BCM2835_REG(BCM2835_TIMER_RLD) = 10000 - 1;
BCM2835_REG(BCM2835_TIMER_DIV) = BCM2835_TIMER_PRESCALE;
BCM2835_REG(BCM2835_TIMER_CLI) = 0;
BCM2835_REG(BCM2835_TIMER_CTL) = 0x003E00A2;
}
static void raspberrypi_clock_cleanup(void)
{
rtems_status_code sc = RTEMS_SUCCESSFUL;
/* Remove interrupt handler */
sc = rtems_interrupt_handler_remove(
BCM2835_IRQ_ID_TIMER_0,
(rtems_interrupt_handler) Clock_isr,
NULL
);
if (sc != RTEMS_SUCCESSFUL) {
rtems_fatal_error_occurred(0xdeadbeef);
}
}
/*
* Return the nanoseconds since last tick
*/
static uint32_t raspberrypi_clock_nanoseconds_since_last_tick(void)
{
return 0;
}
#define Clock_driver_support_at_tick() raspberrypi_clock_at_tick()
#define Clock_driver_support_initialize_hardware() raspberrypi_clock_initialize()
#define Clock_driver_support_install_isr(isr, old_isr) \
do { \
raspberrypi_clock_handler_install(); \
old_isr = NULL; \
} while (0)
#define Clock_driver_support_shutdown_hardware() raspberrypi_clock_cleanup()
#define Clock_driver_nanoseconds_since_last_tick \
raspberrypi_clock_nanoseconds_since_last_tick
#include "../../../shared/clockdrv_shell.h"
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