1 | /* ckinit.c |
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2 | * |
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3 | * This file contains the clock driver initialization for the IDT 4650. |
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4 | * |
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5 | * Author: Craig Lebakken <craigl@transition.com> |
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6 | * |
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7 | * COPYRIGHT (c) 1996 by Transition Networks Inc. |
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8 | * |
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9 | * To anyone who acknowledges that this file is provided "AS IS" |
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10 | * without any express or implied warranty: |
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11 | * permission to use, copy, modify, and distribute this file |
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12 | * for any purpose is hereby granted without fee, provided that |
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13 | * the above copyright notice and this notice appears in all |
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14 | * copies, and that the name of Transition Networks not be used in |
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15 | * advertising or publicity pertaining to distribution of the |
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16 | * software without specific, written prior permission. |
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17 | * Transition Networks makes no representations about the suitability |
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18 | * of this software for any purpose. |
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19 | * |
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20 | * Derived from c/src/lib/libbsp/no_cpu/no_bsp/clock/ckinit.c: |
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21 | * |
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22 | * COPYRIGHT (c) 1989-1999. |
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23 | * On-Line Applications Research Corporation (OAR). |
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24 | * |
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25 | * The license and distribution terms for this file may be |
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26 | * found in the file LICENSE in this distribution or at |
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27 | * http://www.rtems.org/license/LICENSE. |
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28 | */ |
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29 | |
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30 | /* |
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31 | * Rather than deleting this, it is commented out to (hopefully) help |
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32 | * the submitter send updates. |
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33 | * |
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34 | * static char _sccsid[] = "@(#)ckinit.c 08/20/96 1.3\n"; |
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35 | */ |
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36 | |
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37 | |
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38 | #include <stdlib.h> |
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39 | |
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40 | #include <rtems.h> |
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41 | #include <rtems/libio.h> |
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42 | |
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43 | #define EXT_INT5 0x8000 /* external interrupt 5 */ |
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44 | |
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45 | #include "clock.h" |
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46 | |
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47 | extern uint32_t bsp_clicks_per_microsecond; |
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48 | |
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49 | /* to avoid including the bsp */ |
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50 | mips_isr_entry set_vector( rtems_isr_entry, rtems_vector_number, int ); |
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51 | |
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52 | void Clock_exit( void ); |
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53 | rtems_isr Clock_isr( rtems_vector_number vector ); |
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54 | |
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55 | |
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56 | /* |
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57 | * The interrupt vector number associated with the clock tick device |
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58 | * driver. |
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59 | */ |
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60 | |
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61 | #define CLOCK_VECTOR_MASK EXT_INT5 |
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62 | #define CLOCK_VECTOR 0x7 |
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63 | |
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64 | /* |
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65 | * Clock_driver_ticks is a monotonically increasing counter of the |
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66 | * number of clock ticks since the driver was initialized. |
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67 | */ |
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68 | |
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69 | volatile uint32_t Clock_driver_ticks; |
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70 | |
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71 | /* |
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72 | * Clock_isrs is the number of clock ISRs until the next invocation of |
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73 | * the RTEMS clock tick routine. The clock tick device driver |
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74 | * gets an interrupt once a millisecond and counts down until the |
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75 | * length of time between the user configured microseconds per tick |
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76 | * has passed. |
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77 | */ |
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78 | |
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79 | uint32_t Clock_isrs; /* ISRs until next tick */ |
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80 | |
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81 | /* |
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82 | * These are set by clock driver during its init |
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83 | */ |
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84 | |
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85 | rtems_device_major_number rtems_clock_major = ~0; |
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86 | rtems_device_minor_number rtems_clock_minor; |
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87 | |
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88 | /* |
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89 | * The previous ISR on this clock tick interrupt vector. |
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90 | */ |
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91 | |
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92 | rtems_isr_entry Old_ticker; |
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93 | |
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94 | void Clock_exit( void ); |
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95 | |
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96 | static uint32_t mips_timer_rate = 0; |
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97 | |
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98 | /* |
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99 | * Isr Handler |
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100 | */ |
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101 | |
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102 | rtems_isr Clock_isr( |
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103 | rtems_vector_number vector |
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104 | ) |
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105 | { |
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106 | /* |
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107 | * bump the number of clock driver ticks since initialization |
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108 | * |
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109 | * determine if it is time to announce the passing of tick as configured |
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110 | * to RTEMS through the rtems_clock_tick directive |
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111 | * |
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112 | * perform any timer dependent tasks |
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113 | */ |
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114 | |
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115 | /* refresh the internal CPU timer */ |
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116 | mips_set_timer( mips_timer_rate ); |
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117 | |
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118 | Clock_driver_ticks += 1; |
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119 | |
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120 | rtems_clock_tick(); |
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121 | } |
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122 | |
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123 | /* User callback shell (set from Clock_Control) */ |
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124 | static void (*user_callback)(void); |
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125 | |
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126 | rtems_isr User_Clock_isr( |
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127 | rtems_vector_number vector |
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128 | ) |
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129 | { |
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130 | /* refresh the internal CPU timer */ |
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131 | mips_set_timer( mips_timer_rate ); |
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132 | |
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133 | if (user_callback) |
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134 | user_callback(); |
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135 | } |
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136 | |
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137 | /* |
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138 | * Install_clock |
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139 | * |
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140 | * Install a clock tick handleR and reprograms the chip. This |
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141 | * is used to initially establish the clock tick. |
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142 | */ |
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143 | |
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144 | void Install_clock( |
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145 | rtems_isr_entry clock_isr |
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146 | ) |
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147 | { |
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148 | /* |
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149 | * Initialize the clock tick device driver variables |
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150 | */ |
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151 | |
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152 | Clock_driver_ticks = 0; |
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153 | Clock_isrs = rtems_configuration_get_milliseconds_per_tick(); |
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154 | |
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155 | Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 ); |
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156 | /* |
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157 | * Hardware specific initialize goes here |
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158 | */ |
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159 | |
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160 | mips_timer_rate = rtems_configuration_get_microseconds_per_tick() * |
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161 | bsp_clicks_per_microsecond; |
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162 | mips_set_timer( mips_timer_rate ); |
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163 | mips_enable_in_interrupt_mask(CLOCK_VECTOR_MASK); |
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164 | |
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165 | /* |
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166 | * Schedule the clock cleanup routine to execute if the application exits. |
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167 | */ |
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168 | |
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169 | atexit( Clock_exit ); |
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170 | } |
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171 | |
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172 | /* |
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173 | * Clean up before the application exits |
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174 | */ |
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175 | |
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176 | void Clock_exit( void ) |
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177 | { |
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178 | /* mips: turn off the timer interrupts */ |
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179 | mips_disable_in_interrupt_mask(CLOCK_VECTOR_MASK); |
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180 | } |
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181 | |
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182 | /* |
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183 | * Clock_initialize |
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184 | * |
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185 | * Device driver entry point for clock tick driver initialization. |
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186 | */ |
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187 | |
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188 | rtems_device_driver Clock_initialize( |
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189 | rtems_device_major_number major, |
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190 | rtems_device_minor_number minor, |
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191 | void *pargp |
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192 | ) |
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193 | { |
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194 | Install_clock( Clock_isr ); |
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195 | |
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196 | /* |
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197 | * make major/minor avail to others such as shared memory driver |
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198 | */ |
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199 | |
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200 | rtems_clock_major = major; |
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201 | rtems_clock_minor = minor; |
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202 | |
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203 | return RTEMS_SUCCESSFUL; |
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204 | } |
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