diff options
Diffstat (limited to 'c/src/lib/libbsp/i386/force386/clock/ckinit.c')
-rw-r--r-- | c/src/lib/libbsp/i386/force386/clock/ckinit.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/i386/force386/clock/ckinit.c b/c/src/lib/libbsp/i386/force386/clock/ckinit.c new file mode 100644 index 0000000000..49644a2edc --- /dev/null +++ b/c/src/lib/libbsp/i386/force386/clock/ckinit.c @@ -0,0 +1,135 @@ +/* Clock_initialize + * + * This routine initializes the Motorola MFP 68901 on the + * FORCE CPU386 board. The tick frequency is 1 millisecond. + * + * Input parameters: NONE + * + * Output parameters: NONE + * + * COPYRIGHT (c) 1989-1997. + * On-Line Applications Research Corporation (OAR). + * Copyright assigned to U.S. Government, 1994. + * + * The license and distribution terms for this file may in + * the file LICENSE in this distribution or at + * http://www.OARcorp.com/rtems/license.html. + * + * $Id$ + */ + +#include <bsp.h> + +#include <rtems/libio.h> + +#include <stdlib.h> + +#define CLOCK_VECTOR 0x38 + +rtems_unsigned32 Clock_isrs; /* ISRs until next tick */ + +volatile rtems_unsigned32 Clock_driver_ticks; + +rtems_isr_entry Old_ticker; + +void Clock_exit( void ); + +/* + * These are set by clock driver during its init + */ + +rtems_device_major_number rtems_clock_major = ~0; +rtems_device_major_number rtems_clock_minor = 0; + +/* + * This is the ISR handler. + */ + +rtems_isr Clock_isr( + rtems_vector_number vector +) +{ + /* enable_tracing(); */ + Clock_driver_ticks += 1; + if ( Clock_isrs == 1 ) { + rtems_clock_tick(); + Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000; + } + else + Clock_isrs -= 1; +} + +void Install_clock( + rtems_isr_entry clock_isr +) +{ + Clock_driver_ticks = 0; + Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000; + + if ( BSP_Configuration.ticks_per_timeslice ) { + Old_ticker = ( rtems_isr_entry ) set_vector( clock_isr, CLOCK_VECTOR, 1 ); + outport_byte( TBCR, 0x14 ); /* reset it, delay mode, 50X */ + outport_byte( TBDR, 0x50 ); /* 1 millisecond */ + outport_byte( IERA, 0x41 ); /* enable interrupt for B */ + } + atexit( Clock_exit ); +} + +void Clock_exit( void ) +{ + if ( BSP_Configuration.ticks_per_timeslice ) { + outport_byte( TBCR, 0x00 ); /* initial value */ + outport_byte( IERA, 0x40 ); /* disable interrupt */ + /* ??? Is "do not restore old vector" causing problems? */ + } +} + +rtems_device_driver Clock_initialize( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *pargp +) +{ + Install_clock( Clock_isr ); + + /* + * make major/minor avail to others such as shared memory driver + */ + + rtems_clock_major = major; + rtems_clock_minor = minor; + + return RTEMS_SUCCESSFUL; +} + +rtems_device_driver Clock_control( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *pargp +) +{ + rtems_unsigned32 isrlevel; + rtems_libio_ioctl_args_t *args = pargp; + + if (args == 0) + goto done; + + /* + * This is hokey, but until we get a defined interface + * to do this, it will just be this simple... + */ + + if (args->command == rtems_build_name('I', 'S', 'R', ' ')) + { + Clock_isr(CLOCK_VECTOR); + } + else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) + { + rtems_interrupt_disable( isrlevel ); + (void) set_vector( args->buffer, CLOCK_VECTOR, 1 ); + rtems_interrupt_enable( isrlevel ); + } + +done: + return RTEMS_SUCCESSFUL; +} |