forked from Imagelibrary/rtems
a6b2080e1c
This function is no longer supported by the standard clock driver implementation (clockimpl.h). Update #3436.
90 lines
2.5 KiB
C
90 lines
2.5 KiB
C
/*
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* This routine initializes the Tick Timer 2 on the MVME162 board.
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* The tick frequency is 1 millisecond.
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*/
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/*
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* COPYRIGHT (c) 1989-1999.
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* On-Line Applications Research Corporation (OAR).
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*
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* The license and distribution terms for this file may be
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* found in the file LICENSE in this distribution or at
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* http://www.rtems.org/license/LICENSE.
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*
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* Modifications of respective RTEMS file: COPYRIGHT (c) 1994.
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* EISCAT Scientific Association. M.Savitski
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*
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* This material is a part of the MVME162 Board Support Package
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* for the RTEMS executive. Its licensing policies are those of the
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* RTEMS above.
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*/
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#include <stdlib.h>
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#include <bsp.h>
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#include <rtems/clockdrv.h>
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#define MS_COUNT 1000 /* T2's countdown constant (1 ms) */
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#define CLOCK_INT_LEVEL 6 /* T2's interrupt level */
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uint32_t Clock_isrs; /* ISRs until next tick */
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volatile uint32_t Clock_driver_ticks; /* ticks since initialization */
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rtems_isr_entry Old_ticker;
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static void Clock_exit( void );
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#define CLOCK_VECTOR (VBR0 * 0x10 + 0x9)
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/*
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* ISR Handler
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*/
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static rtems_isr Clock_isr(rtems_vector_number vector)
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{
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Clock_driver_ticks += 1;
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lcsr->timer_cnt_2 = 0; /* clear counter */
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lcsr->intr_clear |= 0x02000000;
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if ( Clock_isrs == 1 ) {
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rtems_clock_tick();
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Clock_isrs = rtems_configuration_get_microseconds_per_tick() / 1000;
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}
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else
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Clock_isrs -= 1;
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}
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static void Install_clock(rtems_isr_entry clock_isr )
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{
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Clock_driver_ticks = 0;
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Clock_isrs = rtems_configuration_get_microseconds_per_tick() / 1000;
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Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 );
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lcsr->vector_base |= MASK_INT; /* unmask VMEchip2 interrupts */
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lcsr->to_ctl = 0xE7; /* prescaler to 1 MHz (see Appendix A1) */
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lcsr->timer_cmp_2 = MS_COUNT;
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lcsr->timer_cnt_2 = 0; /* clear counter */
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lcsr->board_ctl |= 0x700; /* increment, reset-on-compare, and */
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/* clear-overflow-cnt */
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lcsr->intr_level[0] |= CLOCK_INT_LEVEL * 0x10; /* set int level */
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lcsr->intr_ena |= 0x02000000; /* enable tick timer 2 interrupt */
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atexit( Clock_exit );
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}
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void Clock_exit( void )
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{
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/* Dummy for now. See other m68k BSP's for code examples */
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}
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rtems_device_driver Clock_initialize(
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rtems_device_major_number major,
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rtems_device_minor_number minor,
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void *pargp
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)
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{
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Install_clock( Clock_isr );
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return RTEMS_SUCCESSFUL;
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}
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