[752cd8f] | 1 | /* Clock_initialize |
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| 2 | * |
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| 3 | * This routine initializes the Timer/Counter on the Intel |
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| 4 | * 386ex evaluation board. |
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| 5 | * |
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| 6 | * The tick frequency is 1 millisecond. |
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| 7 | * |
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| 8 | * Input parameters: NONE |
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| 9 | * |
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| 10 | * Output parameters: NONE |
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| 11 | * |
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| 12 | * COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994. |
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| 13 | * On-Line Applications Research Corporation (OAR). |
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| 14 | * All rights assigned to U.S. Government, 1994. |
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| 15 | * |
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| 16 | * This material may be reproduced by or for the U.S. Government pursuant |
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| 17 | * to the copyright license under the clause at DFARS 252.227-7013. This |
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| 18 | * notice must appear in all copies of this file and its derivatives. |
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| 19 | * |
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| 20 | * $Id$ |
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| 21 | */ |
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| 22 | |
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| 23 | #include <bsp.h> |
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| 24 | #include <clockdrv.h> |
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| 25 | #include <stdlib.h> |
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| 26 | |
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| 27 | volatile rtems_unsigned32 Clock_driver_ticks; |
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| 28 | rtems_unsigned32 Clock_isrs; /* ISRs until next tick */ |
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| 29 | rtems_isr_entry Old_ticker; |
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| 30 | |
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| 31 | rtems_device_driver Clock_initialize( |
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| 32 | rtems_device_major_number major, |
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| 33 | rtems_device_minor_number minor, |
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| 34 | void *pargp, |
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| 35 | rtems_id tid, |
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| 36 | rtems_unsigned32 *rval |
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| 37 | ) |
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| 38 | { |
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| 39 | Install_clock( Clock_isr ); |
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| 40 | } |
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| 41 | |
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| 42 | void ReInstall_clock( |
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| 43 | rtems_isr_entry clock_isr |
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| 44 | ) |
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| 45 | { |
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| 46 | rtems_unsigned32 isrlevel = 0; |
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| 47 | |
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| 48 | rtems_interrupt_disable( isrlevel ); |
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| 49 | (void) set_vector( clock_isr, 0x20, 1 ); /* was 0x38 */ |
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| 50 | rtems_interrupt_enable( isrlevel ); |
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| 51 | } |
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| 52 | |
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| 53 | void Install_clock( |
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| 54 | rtems_isr_entry clock_isr |
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| 55 | ) |
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| 56 | { |
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| 57 | Clock_driver_ticks = 0; |
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| 58 | Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000; |
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| 59 | |
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| 60 | if ( BSP_Configuration.ticks_per_timeslice ) { |
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| 61 | Old_ticker = ( rtems_isr_entry ) set_vector( clock_isr, 0x20, 1 ); |
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| 62 | /* was 0x38 */ |
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| 63 | |
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| 64 | /* The following is already set up in interns.s -> |
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| 65 | ( This is test code only... production code will move the |
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| 66 | TMRCFG stuff here ) |
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| 67 | */ |
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| 68 | #define TMR0 0xF040 |
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| 69 | #define TMR1 0xF041 |
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| 70 | #define TMR2 0xF042 |
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| 71 | #define TMRCON 0xF043 |
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| 72 | #define TMRCFG 0xF834 |
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| 73 | |
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| 74 | outport_byte ( TMRCFG , 0x80 ); |
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| 75 | |
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| 76 | outport_byte ( TMRCON , 0x34 ); |
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| 77 | outport_byte ( TMR0 , 0xA8 ); |
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| 78 | outport_byte ( TMR0 , 0x04 ); |
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| 79 | |
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| 80 | outport_byte ( TMRCFG , 0x00 ); |
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| 81 | } |
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| 82 | atexit( Clock_exit ); |
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| 83 | } |
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| 84 | |
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| 85 | void Clock_exit( void ) |
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| 86 | { |
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| 87 | if ( BSP_Configuration.ticks_per_timeslice ) { |
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| 88 | /* outport_byte( TBCR, 0x00 ); */ /* initial value */ |
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| 89 | /* outport_byte( IERA, 0x40 ); */ /* disable interrupt */ |
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| 90 | /* ??? Is "do not restore old vector" causing problems? */ |
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| 91 | } |
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| 92 | } |
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| 93 | |
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