1 | /* ckinit.c |
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2 | * |
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3 | * This file provides a template for the clock device driver initialization. |
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4 | * |
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5 | * COPYRIGHT (c) 1989-1999. |
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6 | * On-Line Applications Research Corporation (OAR). |
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7 | * |
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8 | * The license and distribution terms for this file may be |
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9 | * found in the file LICENSE in this distribution or at |
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10 | * http://www.rtems.com/license/LICENSE. |
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11 | * |
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12 | * $Id$ |
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13 | */ |
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14 | |
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15 | #include <stdlib.h> |
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16 | |
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17 | #include <rtems.h> |
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18 | #include <rtems/libio.h> |
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19 | #include <bsp.h> |
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20 | #include <rtems/c4x/c4xio.h> |
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21 | |
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22 | void Clock_exit( void ); |
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23 | rtems_isr Clock_isr( rtems_vector_number vector ); |
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24 | |
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25 | uint32_t Clock_counter_register_value; |
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26 | |
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27 | /* |
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28 | * The interrupt vector number associated with the clock tick device |
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29 | * driver. |
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30 | */ |
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31 | |
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32 | #define CLOCK_VECTOR 9 |
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33 | |
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34 | /* |
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35 | * Clock_driver_ticks is a monotonically increasing counter of the |
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36 | * number of clock ticks since the driver was initialized. |
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37 | */ |
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38 | |
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39 | volatile uint32_t Clock_driver_ticks; |
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40 | |
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41 | /* |
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42 | * These are set by clock driver during its init |
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43 | */ |
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44 | |
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45 | rtems_device_major_number rtems_clock_major = ~0; |
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46 | rtems_device_minor_number rtems_clock_minor; |
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47 | |
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48 | /* |
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49 | * The previous ISR on this clock tick interrupt vector. |
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50 | */ |
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51 | |
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52 | rtems_isr_entry Old_ticker; |
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53 | |
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54 | void Clock_exit( void ); |
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55 | |
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56 | |
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57 | /* |
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58 | * Isr Handler |
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59 | */ |
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60 | |
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61 | #define FAST_IDLE 1 |
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62 | #if FAST_IDLE |
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63 | int Clock_in_fast_idle_mode = 0; |
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64 | #endif |
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65 | |
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66 | rtems_isr Clock_isr( |
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67 | rtems_vector_number vector |
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68 | ) |
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69 | { |
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70 | /* |
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71 | * The counter register gets reset automatically as well as the |
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72 | * interrupt occurred flag so we should not have to do anything |
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73 | * with the hardware. |
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74 | */ |
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75 | |
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76 | /* |
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77 | * Bump the number of clock driver ticks since initialization |
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78 | */ |
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79 | |
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80 | Clock_driver_ticks += 1; |
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81 | |
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82 | rtems_clock_tick(); |
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83 | |
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84 | #if FAST_IDLE |
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85 | if ( Clock_in_fast_idle_mode ) { |
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86 | if ( _Thread_Executing == _Thread_Idle && _Thread_Heir != _Thread_Idle ) { |
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87 | c4x_timer_stop( C4X_TIMER_0 ); |
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88 | c4x_timer_set_counter( C4X_TIMER_0, 0 ); |
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89 | c4x_timer_set_period( C4X_TIMER_0, Clock_counter_register_value ); |
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90 | c4x_timer_start( C4X_TIMER_0 ); |
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91 | Clock_in_fast_idle_mode = 0; |
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92 | } |
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93 | } else { |
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94 | if ( _Thread_Executing == _Thread_Idle && _Thread_Heir == _Thread_Idle ) { |
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95 | c4x_timer_stop( C4X_TIMER_0 ); |
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96 | c4x_timer_set_counter( C4X_TIMER_0, 0 ); |
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97 | c4x_timer_set_period( C4X_TIMER_0, Clock_counter_register_value >> 5 ); |
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98 | c4x_timer_start( C4X_TIMER_0 ); |
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99 | } |
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100 | } |
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101 | #endif |
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102 | } |
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103 | |
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104 | /* |
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105 | * Install_clock |
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106 | * |
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107 | * Install a clock tick handler and reprograms the chip. This |
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108 | * is used to initially establish the clock tick. |
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109 | */ |
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110 | |
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111 | void Install_clock( |
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112 | rtems_isr_entry clock_isr |
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113 | ) |
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114 | { |
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115 | extern int _ClockFrequency; |
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116 | float tmp; |
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117 | int tmpi; |
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118 | /* |
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119 | * Initialize the clock tick device driver variables |
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120 | */ |
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121 | |
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122 | Clock_driver_ticks = 0; |
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123 | |
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124 | tmpi = ((int) &_ClockFrequency) * 1000000; /* ClockFrequency is in Mhz */ |
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125 | tmp = (float) tmpi / 2.0; |
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126 | tmp = ((float) BSP_Configuration.microseconds_per_tick / 1000000.0) * (tmp); |
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127 | |
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128 | Clock_counter_register_value = (unsigned int) tmp; |
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129 | #if 0 |
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130 | Clock_counter_register_value = |
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131 | (uint32_t) ((float) BSP_Configuration.microseconds_per_tick / |
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132 | ((float)_ClockFrequency / 2.0))); |
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133 | #endif |
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134 | c4x_timer_stop( C4X_TIMER_0 ); |
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135 | c4x_timer_set_counter( C4X_TIMER_0, 0 ); |
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136 | c4x_timer_set_period( C4X_TIMER_0, Clock_counter_register_value ); |
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137 | c4x_timer_start( C4X_TIMER_0 ); |
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138 | |
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139 | #if defined(_C4x) |
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140 | c4x_set_iee( c4x_get_iie() | 0x1 ); /* should be ETINT0 */ |
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141 | #else |
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142 | c3x_set_ie( c3x_get_ie() | 0x100 ); |
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143 | #endif |
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144 | |
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145 | /* |
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146 | * If ticks_per_timeslice is configured as non-zero, then the user |
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147 | * wants a clock tick. |
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148 | */ |
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149 | |
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150 | Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 ); |
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151 | /* |
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152 | * Hardware specific initialize goes here |
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153 | */ |
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154 | |
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155 | /* XXX */ |
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156 | |
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157 | /* |
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158 | * Schedule the clock cleanup routine to execute if the application exits. |
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159 | */ |
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160 | |
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161 | atexit( Clock_exit ); |
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162 | } |
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163 | |
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164 | /* |
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165 | * Clean up before the application exits |
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166 | */ |
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167 | |
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168 | void Clock_exit( void ) |
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169 | { |
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170 | /* XXX: turn off the timer interrupts */ |
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171 | |
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172 | /* XXX: If necessary, restore the old vector */ |
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173 | } |
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174 | |
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175 | /* |
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176 | * Clock_initialize |
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177 | * |
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178 | * Device driver entry point for clock tick driver initialization. |
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179 | */ |
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180 | |
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181 | rtems_device_driver Clock_initialize( |
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182 | rtems_device_major_number major, |
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183 | rtems_device_minor_number minor, |
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184 | void *pargp |
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185 | ) |
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186 | { |
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187 | Install_clock( Clock_isr ); |
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188 | |
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189 | /* |
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190 | * make major/minor avail to others such as shared memory driver |
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191 | */ |
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192 | |
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193 | rtems_clock_major = major; |
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194 | rtems_clock_minor = minor; |
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195 | |
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196 | return RTEMS_SUCCESSFUL; |
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197 | } |
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198 | |
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199 | rtems_device_driver Clock_control( |
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200 | rtems_device_major_number major, |
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201 | rtems_device_minor_number minor, |
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202 | void *pargp |
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203 | ) |
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204 | { |
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205 | uint32_t isrlevel; |
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206 | rtems_libio_ioctl_args_t *args = pargp; |
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207 | |
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208 | if (args == 0) |
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209 | goto done; |
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210 | |
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211 | /* |
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212 | * This is hokey, but until we get a defined interface |
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213 | * to do this, it will just be this simple... |
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214 | */ |
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215 | |
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216 | if (args->command == rtems_build_name('I', 'S', 'R', ' ')) |
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217 | { |
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218 | Clock_isr(CLOCK_VECTOR); |
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219 | } |
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220 | else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) |
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221 | { |
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222 | rtems_interrupt_disable( isrlevel ); |
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223 | (void) set_vector( args->buffer, CLOCK_VECTOR, 1 ); |
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224 | rtems_interrupt_enable( isrlevel ); |
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225 | } |
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226 | |
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227 | done: |
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228 | return RTEMS_SUCCESSFUL; |
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229 | } |
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