[acc25ee] | 1 | /* |
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| 2 | * Clock Tick Device Driver |
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| 3 | * |
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| 4 | * This routine utilizes the Decrementer Register common to the PPC family. |
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| 5 | * |
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| 6 | * The tick frequency is directly programmed to the configured number of |
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| 7 | * microseconds per tick. |
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| 8 | * |
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| 9 | * COPYRIGHT (c) 1989-1997. |
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| 10 | * On-Line Applications Research Corporation (OAR). |
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| 11 | * |
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| 12 | * The license and distribution terms for this file may in |
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| 13 | * the file LICENSE in this distribution or at |
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| 14 | * http://www.OARcorp.com/rtems/license.html. |
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| 15 | * |
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| 16 | * Modified to support the MPC750. |
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| 17 | * Modifications Copyright (c) 1999 Eric Valette valette@crf.canon.fr |
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| 18 | * |
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| 19 | * $Id$ |
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| 20 | */ |
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| 21 | |
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[a73a977] | 22 | #include <rtems/system.h> |
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[acc25ee] | 23 | #include <rtems.h> |
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| 24 | #include <rtems/libio.h> |
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| 25 | #include <stdlib.h> /* for atexit() */ |
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| 26 | #include <assert.h> |
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| 27 | #include <libcpu/c_clock.h> |
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[5c76213] | 28 | #include <rtems/bspIo.h> /* for printk() */ |
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[acc25ee] | 29 | |
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[cebb89b] | 30 | extern int BSP_connect_clock_handler (void); |
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| 31 | |
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[acc25ee] | 32 | /* |
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| 33 | * Clock ticks since initialization |
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| 34 | */ |
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| 35 | |
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| 36 | volatile rtems_unsigned32 Clock_driver_ticks; |
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| 37 | |
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| 38 | /* |
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| 39 | * This is the value programmed into the count down timer. |
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| 40 | */ |
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| 41 | |
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| 42 | rtems_unsigned32 Clock_Decrementer_value; |
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| 43 | |
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| 44 | /* |
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| 45 | * These are set by clock driver during its init |
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| 46 | */ |
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| 47 | |
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| 48 | rtems_device_major_number rtems_clock_major = ~0; |
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| 49 | rtems_device_minor_number rtems_clock_minor; |
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| 50 | |
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| 51 | void clockOff(void* unused) |
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| 52 | { |
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[0dd1d44] | 53 | /* |
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| 54 | * Nothing to do as we cannot disable all interrupts and |
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| 55 | * the decrementer interrupt enable is MSR_EE |
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| 56 | */ |
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[acc25ee] | 57 | } |
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| 58 | void clockOn(void* unused) |
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| 59 | { |
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| 60 | PPC_Set_decrementer( Clock_Decrementer_value ); |
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| 61 | } |
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| 62 | |
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| 63 | /* |
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| 64 | * Clock_isr |
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| 65 | * |
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| 66 | * This is the clock tick interrupt handler. |
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| 67 | * |
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| 68 | * Input parameters: |
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| 69 | * vector - vector number |
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| 70 | * |
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| 71 | * Output parameters: NONE |
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| 72 | * |
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| 73 | * Return values: NONE |
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| 74 | * |
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| 75 | */ |
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| 76 | void clockIsr() |
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| 77 | { |
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| 78 | /* |
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| 79 | * The driver has seen another tick. |
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| 80 | */ |
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| 81 | |
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| 82 | PPC_Set_decrementer( Clock_Decrementer_value ); |
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| 83 | |
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| 84 | Clock_driver_ticks += 1; |
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| 85 | |
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| 86 | /* |
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| 87 | * Real Time Clock counter/timer is set to automatically reload. |
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| 88 | */ |
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| 89 | |
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| 90 | rtems_clock_tick(); |
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| 91 | } |
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| 92 | |
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| 93 | int clockIsOn(void* unused) |
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| 94 | { |
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| 95 | unsigned32 msr_value; |
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| 96 | |
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| 97 | _CPU_MSR_GET( msr_value ); |
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| 98 | if (msr_value & MSR_EE) return 1; |
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| 99 | return 0; |
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| 100 | } |
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| 101 | |
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| 102 | |
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| 103 | /* |
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| 104 | * Clock_exit |
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| 105 | * |
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| 106 | * This routine allows the clock driver to exit by masking the interrupt and |
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| 107 | * disabling the clock's counter. |
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| 108 | * |
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| 109 | * Input parameters: NONE |
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| 110 | * |
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| 111 | * Output parameters: NONE |
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| 112 | * |
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| 113 | * Return values: NONE |
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| 114 | * |
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| 115 | */ |
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| 116 | |
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| 117 | void Clock_exit( void ) |
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| 118 | { |
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[0dd1d44] | 119 | (void) BSP_disconnect_clock_handler (); |
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[acc25ee] | 120 | } |
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| 121 | |
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| 122 | /* |
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| 123 | * Clock_initialize |
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| 124 | * |
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| 125 | * This routine initializes the clock driver. |
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| 126 | * |
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| 127 | * Input parameters: |
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| 128 | * major - clock device major number |
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| 129 | * minor - clock device minor number |
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| 130 | * parg - pointer to optional device driver arguments |
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| 131 | * |
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| 132 | * Output parameters: NONE |
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| 133 | * |
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| 134 | * Return values: |
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| 135 | * rtems_device_driver status code |
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| 136 | */ |
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| 137 | |
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| 138 | rtems_device_driver Clock_initialize( |
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| 139 | rtems_device_major_number major, |
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| 140 | rtems_device_minor_number minor, |
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| 141 | void *pargp |
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| 142 | ) |
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| 143 | { |
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[95273a6] | 144 | Clock_Decrementer_value = (BSP_bus_frequency/BSP_time_base_divisor)* |
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[8e13ca61] | 145 | (rtems_configuration_get_microseconds_per_tick()/1000); |
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[acc25ee] | 146 | |
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| 147 | if (!BSP_connect_clock_handler ()) { |
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| 148 | printk("Unable to initialize system clock\n"); |
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| 149 | rtems_fatal_error_occurred(1); |
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| 150 | } |
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| 151 | /* make major/minor avail to others such as shared memory driver */ |
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| 152 | |
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| 153 | rtems_clock_major = major; |
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| 154 | rtems_clock_minor = minor; |
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| 155 | |
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| 156 | return RTEMS_SUCCESSFUL; |
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| 157 | } /* Clock_initialize */ |
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| 158 | |
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| 159 | /* |
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| 160 | * Clock_control |
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| 161 | * |
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| 162 | * This routine is the clock device driver control entry point. |
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| 163 | * |
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| 164 | * Input parameters: |
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| 165 | * major - clock device major number |
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| 166 | * minor - clock device minor number |
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| 167 | * parg - pointer to optional device driver arguments |
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| 168 | * |
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| 169 | * Output parameters: NONE |
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| 170 | * |
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| 171 | * Return values: |
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| 172 | * rtems_device_driver status code |
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| 173 | */ |
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| 174 | |
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| 175 | rtems_device_driver Clock_control( |
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| 176 | rtems_device_major_number major, |
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| 177 | rtems_device_minor_number minor, |
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| 178 | void *pargp |
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| 179 | ) |
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| 180 | { |
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| 181 | rtems_libio_ioctl_args_t *args = pargp; |
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| 182 | |
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| 183 | if (args == 0) |
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| 184 | goto done; |
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| 185 | |
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[95273a6] | 186 | Clock_Decrementer_value = (BSP_bus_frequency/BSP_time_base_divisor)* |
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[8e13ca61] | 187 | (rtems_configuration_get_microseconds_per_tick()/1000); |
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[acc25ee] | 188 | |
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| 189 | if (args->command == rtems_build_name('I', 'S', 'R', ' ')) |
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| 190 | clockIsr(); |
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| 191 | else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) |
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| 192 | { |
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| 193 | if (!BSP_connect_clock_handler ()) { |
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| 194 | printk("Error installing clock interrupt handler!\n"); |
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| 195 | rtems_fatal_error_occurred(1); |
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| 196 | } |
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| 197 | } |
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| 198 | done: |
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| 199 | return RTEMS_SUCCESSFUL; |
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| 200 | } |
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| 201 | |
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| 202 | |
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| 203 | |
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| 204 | |
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| 205 | |
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| 206 | |
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