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Diffstat (limited to 'c/src/lib/libbsp/m68k/gen68340/clock/ckinit.c')
| -rw-r--r-- | c/src/lib/libbsp/m68k/gen68340/clock/ckinit.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/m68k/gen68340/clock/ckinit.c b/c/src/lib/libbsp/m68k/gen68340/clock/ckinit.c new file mode 100644 index 0000000000..3a69bbf243 --- /dev/null +++ b/c/src/lib/libbsp/m68k/gen68340/clock/ckinit.c @@ -0,0 +1,185 @@ +/* + * This routine initializes the MC68340/349 Periodic Interval Timer + * + * Based on the `gen68360' board support package, and covered by the + * original distribution terms. + * + * Geoffroy Montel + * France Telecom - CNET/DSM/TAM/CAT + * 4, rue du Clos Courtel + * 35512 CESSON-SEVIGNE + * FRANCE + * + * e-mail: g_montel@yahoo.com + * + * $Id$ + */ + +/* + * Input parameters: NONE + * + * Output parameters: NONE + * + * COPYRIGHT (c) 1989-1998. + * On-Line Applications Research Corporation (OAR). + * Copyright assigned to U.S. Government, 1994. + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.OARcorp.com/rtems/license.html. + */ + +#include <stdlib.h> /* for atexit() */ +#include <bsp.h> +#include <rtems/libio.h> +#include <m68340.h> + +#define CLOCK_VECTOR 120 /* clock isr routine vector in the vbr */ +#define CLOCK_IRQ_LEVEL 6 /* clock isr level */ + +/* + * Clock_driver_ticks is a monotonically increasing counter of the + * number of clock ticks since the driver was initialized. + */ +volatile rtems_unsigned32 Clock_driver_ticks; + +/* + * These are set by clock driver during its init + */ +rtems_device_major_number rtems_clock_major = ~0; +rtems_device_minor_number rtems_clock_minor; + +/* + * Periodic interval timer interrupt handler + */ + +/****************************************************** + Name: Clock_isr + Input parameters: irq vector + Output parameters: none + Description: update # of clock ticks + *****************************************************/ +rtems_isr +Clock_isr (rtems_vector_number vector) +{ + /* + * Announce the clock tick + */ + Clock_driver_ticks++; + rtems_clock_tick(); +} + +/****************************************************** + Name: clock_exit + Input parameters: - + Output parameters: - + Description: turn off periodic time at shutdown + *****************************************************/ +void +Clock_exit (void) +{ + if (BSP_Configuration.ticks_per_timeslice ) { + /* + * Turn off periodic interval timer + */ + SIMPITR = 0; + } +} + +/****************************************************** + Name: Install_clock + Input parameters: the Clock Interrupt Subroutine + Output parameters: - + Description: initialize the periodic interval ticker + called by Clock_Initialize + *****************************************************/ +static void +Install_clock (rtems_isr_entry clock_isr) +{ + unsigned32 pitr_tmp; + + Clock_driver_ticks = 0; + if ( BSP_Configuration.ticks_per_timeslice ) { + + set_vector (clock_isr, CLOCK_VECTOR, 1); + + /* sets the Periodic Interrupt Control Register PICR */ + /* voir a quoi correspond exactement le Clock Vector */ + + SIMPICR = ( CLOCK_IRQ_LEVEL << 8 ) | ( CLOCK_VECTOR ); + + /* sets the PITR count value */ + /* this assumes a 32.765 kHz crystal */ + + /* find out whether prescaler should be enabled or not */ + if ( BSP_Configuration.microseconds_per_tick <= 31128 ) { + pitr_tmp = ( BSP_Configuration.microseconds_per_tick * 8192 ) / 1000000 ; + } + else { + pitr_tmp = ( BSP_Configuration.microseconds_per_tick / 1000000 ) * 16; + /* enable it */ + pitr_tmp |= 0x100; + } + + SIMPITR = (unsigned char) pitr_tmp; + + atexit (Clock_exit); + } +} + +/****************************************************** + Name: Clock_initialize + Input parameters: major & minor numbers + Output parameters: - + Description: main entry for clock initialization + calls the bsp dependant routine + *****************************************************/ +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; +} + +/****************************************************** + Name: Clock_control + Input parameters: major & minor number + Output parameters: + Description: + *****************************************************/ +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) { + /* + * 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 ); + } + } + return RTEMS_SUCCESSFUL; +} |