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/* RTEMS Clock Tick Driver for Blackfin. Uses Blackfin Core Timer.
*
* Copyright (c) 2008 Kallisti Labs, Los Gatos, CA, USA
* written by Allan Hessenflow <allanh@kallisti.com>
*
* 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 <stdlib.h>
#include <rtems/libio.h>
#include <bsp.h>
#include <libcpu/cecRegs.h>
#include <libcpu/coreTimerRegs.h>
#if (BFIN_ON_SKYEYE)
#define CLOCK_DRIVER_USE_FAST_IDLE 1
#endif
volatile uint32_t Clock_driver_ticks;
void Clock_exit(void);
/*
* Major and minor number.
*/
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_minor_number rtems_clock_minor;
static rtems_isr clockISR(rtems_vector_number vector) {
Clock_driver_ticks += 1;
#if CLOCK_DRIVER_USE_FAST_IDLE
do {
rtems_clock_tick();
} while (
_Thread_Heir == _Thread_Executing
&& _Thread_Executing->Start.entry_point
== rtems_configuration_get_idle_task()
);
#else
rtems_clock_tick();
#endif
}
/*
* Clock_exit
*
* This routine allows the clock driver to exit by masking the interrupt and
* disabling the clock's counter.
*
* Input parameters: NONE
*
* Output parameters: NONE
*
* Return values: NONE
*
*/
void Clock_exit(void) {
*(uint32_t volatile *) TCNTL = 0;
}
/*
* Clock_initialize
*
* This routine initializes the clock driver.
*
* Input parameters:
* major - clock device major number
* minor - clock device minor number
* parg - pointer to optional device driver arguments
*
* Output parameters: NONE
*
* Return values:
* rtems_device_driver status code
*/
rtems_device_driver Clock_initialize(rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp) {
Clock_driver_ticks = 0;
set_vector(clockISR, CEC_CORE_TIMER_VECTOR, 1);
*(uint32_t volatile *) TCNTL = TCNTL_TMPWR | TCNTL_TAUTORLD;
*(uint32_t volatile *) TSCALE = 0;
*(uint32_t volatile *) TPERIOD = CCLK / 1000000 *
rtems_configuration_get_microseconds_per_tick();
*(uint32_t volatile *) TCNTL = TCNTL_TMPWR | TCNTL_TAUTORLD | TCNTL_TMREN;
atexit(Clock_exit);
/*
* make major/minor avail to others such as shared memory driver
*/
rtems_clock_major = major;
rtems_clock_minor = minor;
return RTEMS_SUCCESSFUL;
}
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