[cd67dca] | 1 | /* |
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| 2 | * Clock Driver for SH4 simulator (timer interrupt not supported now). |
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| 3 | * |
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| 4 | * Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia |
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| 5 | * Author: Victor V. Vengerov <vvv@oktet.ru> |
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| 6 | * |
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| 7 | * COPYRIGHT (c) 1989-2001. |
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| 8 | * On-Line Applications Research Corporation (OAR). |
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| 9 | * |
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| 10 | * The license and distribution terms for this file may be |
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| 11 | * found in the file LICENSE in this distribution or at |
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| 12 | * |
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| 13 | * http://www.OARcorp.com/rtems/license.html. |
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| 14 | * |
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| 15 | * $Id$ |
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| 16 | */ |
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| 17 | |
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| 18 | #include <stdlib.h> |
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| 19 | #include <bsp.h> |
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| 20 | #include <rtems/libio.h> |
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| 21 | |
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| 22 | /* |
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| 23 | * Clock_driver_ticks is a monotonically increasing counter of the |
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| 24 | * number of clock ticks since the driver was initialized. |
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| 25 | */ |
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| 26 | volatile rtems_unsigned32 Clock_driver_ticks; |
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| 27 | |
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| 28 | |
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| 29 | /* |
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| 30 | * These are set by clock driver during its init |
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| 31 | */ |
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| 32 | |
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| 33 | rtems_device_major_number rtems_clock_major = ~0; |
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| 34 | rtems_device_minor_number rtems_clock_minor; |
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| 35 | |
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| 36 | rtems_isr (*rtems_clock_hook)(rtems_vector_number) = NULL; |
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| 37 | |
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| 38 | static void |
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| 39 | set_clock_period(rtems_unsigned32 period) |
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| 40 | { |
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| 41 | asm volatile ("\tmov %0,r0\n" |
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| 42 | "\ttrapa\t#4\n" |
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| 43 | : |
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| 44 | : "r" (period) |
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| 45 | : "r0" ); |
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| 46 | } |
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| 47 | |
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| 48 | /* Clock_isr -- |
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| 49 | * This handles the timer interrupt by clearing the timer's interrupt |
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| 50 | * flag and announcing the clock tick to the system. |
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| 51 | * |
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| 52 | * PARAMETERS: |
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| 53 | * vector - timer interrupt vector number |
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| 54 | * |
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| 55 | * RETURNS: |
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| 56 | * none |
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| 57 | */ |
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| 58 | rtems_isr |
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| 59 | Clock_isr (rtems_vector_number vector) |
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| 60 | { |
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| 61 | /* Announce the clock tick */ |
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| 62 | Clock_driver_ticks++; |
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| 63 | rtems_clock_tick(); |
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| 64 | } |
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| 65 | |
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| 66 | |
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| 67 | /* Clock_exit -- |
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| 68 | * This shuts down the timer if it was enabled and removes it |
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| 69 | * from the interrupt mask. |
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| 70 | * |
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| 71 | * PARAMETERS: |
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| 72 | * none |
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| 73 | * |
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| 74 | * RETURNS: |
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| 75 | * none |
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| 76 | */ |
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| 77 | void |
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| 78 | Clock_exit(void) |
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| 79 | { |
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| 80 | if (BSP_Configuration.ticks_per_timeslice) |
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| 81 | { |
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| 82 | /* disable all timer1 interrupts */ |
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| 83 | set_clock_period(0); |
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| 84 | } |
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| 85 | } |
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| 86 | |
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| 87 | |
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| 88 | /* Install_clock -- |
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| 89 | * This initialises timer1 with the BSP timeslice config value |
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| 90 | * as a reference and sets up the interrupt handler for clock ticks. |
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| 91 | * |
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| 92 | * PARAMETERS: |
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| 93 | * clock_isr - clock interrupt handler routine |
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| 94 | * |
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| 95 | * RETURNS: |
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| 96 | * none. |
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| 97 | */ |
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| 98 | static void |
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| 99 | Install_clock(rtems_isr_entry clock_isr) |
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| 100 | { |
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| 101 | rtems_unsigned32 period; |
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| 102 | Clock_driver_ticks = 0; |
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| 103 | if (BSP_Configuration.ticks_per_timeslice) |
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| 104 | { |
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[a1a84a3] | 105 | rtems_isr_entry old_isr; |
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[cd67dca] | 106 | period = Cpu_table.clicks_per_second / |
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| 107 | BSP_Configuration.ticks_per_timeslice; |
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| 108 | |
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| 109 | /* Configure timer interrupts */ |
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| 110 | set_clock_period(period); |
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| 111 | |
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| 112 | /* Register the interrupt handler */ |
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| 113 | rtems_interrupt_catch(clock_isr, CLOCK_VECTOR, &old_isr); |
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| 114 | |
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| 115 | /* Register the driver exit procedure so we can shutdown */ |
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| 116 | atexit(Clock_exit); |
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| 117 | } |
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| 118 | } |
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| 119 | |
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| 120 | |
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| 121 | /* Clock_initialize -- |
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| 122 | * This is called to setup the clock driver. It calls the hardware |
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| 123 | * setup function and make the driver major/minor values available |
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| 124 | * for other. |
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| 125 | * |
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| 126 | * PARAMETERS: |
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| 127 | * major - clock device major number |
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| 128 | * minor - clock device minor number |
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| 129 | * pargp - device driver initialization argument (not used) |
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| 130 | * |
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| 131 | * RETURNS: |
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| 132 | * RTEMS status code |
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| 133 | */ |
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| 134 | rtems_device_driver |
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| 135 | Clock_initialize(rtems_device_major_number major, |
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| 136 | rtems_device_minor_number minor, |
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| 137 | void *pargp) |
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| 138 | { |
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| 139 | Install_clock (Clock_isr); |
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| 140 | |
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| 141 | /* Make major/minor avail to others such as shared memory driver */ |
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| 142 | rtems_clock_major = major; |
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| 143 | rtems_clock_minor = minor; |
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| 144 | |
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| 145 | return RTEMS_SUCCESSFUL; |
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| 146 | } |
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| 147 | |
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| 148 | |
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| 149 | /* Clock_control -- |
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| 150 | * I/O control (IOCTL) function for Clock driver. At this moment this |
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| 151 | * just runs the interrupt handler or re-registers the interrupt handler |
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| 152 | * on request. |
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| 153 | * |
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| 154 | * PARAMETERS: |
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| 155 | * major - clock major device number |
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| 156 | * minor - clock minor device number |
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| 157 | * pargp - pointer to IOCTL arguments |
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| 158 | * |
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| 159 | * RETURNS: |
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| 160 | * RTEMS status code |
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| 161 | */ |
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| 162 | rtems_device_driver |
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| 163 | Clock_control(rtems_device_major_number major, |
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| 164 | rtems_device_minor_number minor, |
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| 165 | void *pargp) |
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| 166 | { |
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| 167 | rtems_unsigned32 isrlevel; |
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| 168 | rtems_libio_ioctl_args_t *args = pargp; |
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| 169 | |
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| 170 | if (args) |
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| 171 | { |
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[a1a84a3] | 172 | rtems_isr_entry old_isr; |
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[cd67dca] | 173 | /* |
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| 174 | * This is hokey, but until we get a defined interface |
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| 175 | * to do this, it will just be this simple... |
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| 176 | */ |
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| 177 | if (args->command == rtems_build_name('I', 'S', 'R', ' ')) |
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| 178 | { |
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| 179 | Clock_isr(CLOCK_VECTOR); |
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| 180 | } |
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| 181 | else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) |
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| 182 | { |
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| 183 | rtems_interrupt_disable( isrlevel ); |
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| 184 | rtems_interrupt_catch(Clock_isr, CLOCK_VECTOR, &old_isr); |
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| 185 | rtems_interrupt_enable( isrlevel ); |
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| 186 | } |
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| 187 | } |
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| 188 | return RTEMS_SUCCESSFUL; |
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| 189 | } |
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