diff options
Diffstat (limited to 'bsps/m68k/mvme162/clock/ckinit.c')
-rw-r--r-- | bsps/m68k/mvme162/clock/ckinit.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/bsps/m68k/mvme162/clock/ckinit.c b/bsps/m68k/mvme162/clock/ckinit.c new file mode 100644 index 0000000000..f4b680e170 --- /dev/null +++ b/bsps/m68k/mvme162/clock/ckinit.c @@ -0,0 +1,89 @@ +/* + * This routine initializes the Tick Timer 2 on the MVME162 board. + * The tick frequency is 1 millisecond. + */ + +/* + * COPYRIGHT (c) 1989-1999. + * On-Line Applications Research Corporation (OAR). + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + * + * Modifications of respective RTEMS file: COPYRIGHT (c) 1994. + * EISCAT Scientific Association. M.Savitski + * + * This material is a part of the MVME162 Board Support Package + * for the RTEMS executive. Its licensing policies are those of the + * RTEMS above. + */ + +#include <stdlib.h> + +#include <bsp.h> +#include <rtems/clockdrv.h> + +#define MS_COUNT 1000 /* T2's countdown constant (1 ms) */ +#define CLOCK_INT_LEVEL 6 /* T2's interrupt level */ + +uint32_t Clock_isrs; /* ISRs until next tick */ +volatile uint32_t Clock_driver_ticks; /* ticks since initialization */ +rtems_isr_entry Old_ticker; + +void Clock_exit( void ); + +#define CLOCK_VECTOR (VBR0 * 0x10 + 0x9) + +/* + * ISR Handler + */ +static rtems_isr Clock_isr(rtems_vector_number vector) +{ + Clock_driver_ticks += 1; + lcsr->timer_cnt_2 = 0; /* clear counter */ + lcsr->intr_clear |= 0x02000000; + + if ( Clock_isrs == 1 ) { + rtems_clock_tick(); + Clock_isrs = rtems_configuration_get_microseconds_per_tick() / 1000; + } + else + Clock_isrs -= 1; +} + +static void Install_clock(rtems_isr_entry clock_isr ) +{ + + Clock_driver_ticks = 0; + Clock_isrs = rtems_configuration_get_microseconds_per_tick() / 1000; + + Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 ); + lcsr->vector_base |= MASK_INT; /* unmask VMEchip2 interrupts */ + lcsr->to_ctl = 0xE7; /* prescaler to 1 MHz (see Appendix A1) */ + lcsr->timer_cmp_2 = MS_COUNT; + lcsr->timer_cnt_2 = 0; /* clear counter */ + lcsr->board_ctl |= 0x700; /* increment, reset-on-compare, and */ + /* clear-overflow-cnt */ + + lcsr->intr_level[0] |= CLOCK_INT_LEVEL * 0x10; /* set int level */ + lcsr->intr_ena |= 0x02000000; /* enable tick timer 2 interrupt */ + + atexit( Clock_exit ); +} + +void Clock_exit( void ) +{ +/* Dummy for now. See other m68k BSP's for code examples */ +} + +rtems_device_driver Clock_initialize( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *pargp +) +{ + Install_clock( Clock_isr ); + + return RTEMS_SUCCESSFUL; +} |