1 | /*-------------------------------------------------------------------------+ |
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2 | | ckinit.c v1.1 - PC386 BSP - 1997/08/07 |
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3 | +--------------------------------------------------------------------------+ |
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4 | | This file contains the PC386 clock package. |
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5 | +--------------------------------------------------------------------------+ |
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6 | | (C) Copyright 1997 - |
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7 | | - NavIST Group - Real-Time Distributed Systems and Industrial Automation |
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8 | | |
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9 | | http://pandora.ist.utl.pt |
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10 | | |
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11 | | Instituto Superior Tecnico * Lisboa * PORTUGAL |
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12 | +--------------------------------------------------------------------------+ |
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13 | | Disclaimer: |
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14 | | |
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15 | | This file is provided "AS IS" without warranty of any kind, either |
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16 | | expressed or implied. |
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17 | +--------------------------------------------------------------------------+ |
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18 | | This code is based on: |
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19 | | ckinit.c,v 1.4 1995/12/19 20:07:13 joel Exp - go32 BSP |
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20 | | With the following copyright notice: |
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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 found in the file LICENSE in this distribution or at |
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27 | | * http://www.rtems.com/license/LICENSE. |
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28 | | ************************************************************************** |
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29 | | |
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30 | | $Id$ |
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31 | +--------------------------------------------------------------------------*/ |
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32 | |
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33 | #include <stdlib.h> |
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34 | |
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35 | #include <bsp.h> |
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36 | #include <bsp/irq.h> |
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37 | #include <rtems/libio.h> |
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38 | |
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39 | /*-------------------------------------------------------------------------+ |
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40 | | Macros |
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41 | +--------------------------------------------------------------------------*/ |
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42 | #if 0 |
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43 | /* This was dropped in the last revision. Its a nice thing to know. */ |
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44 | #define TICKS_PER_SECOND() \ |
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45 | (1000000 / (Clock_isrs_per_tick * microseconds_per_isr)) |
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46 | #endif /* 0 */ |
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47 | |
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48 | /*-------------------------------------------------------------------------+ |
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49 | | Global Variables |
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50 | +--------------------------------------------------------------------------*/ |
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51 | |
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52 | volatile uint32_t Clock_driver_ticks; /* Tick (interrupt) counter. */ |
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53 | uint32_t Clock_isrs_per_tick; /* ISRs per tick. */ |
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54 | uint32_t Clock_isrs; /* ISRs until next tick. */ |
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55 | |
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56 | /* The following variables are set by the clock driver during its init */ |
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57 | |
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58 | rtems_device_major_number rtems_clock_major = ~0; |
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59 | rtems_device_minor_number rtems_clock_minor; |
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60 | |
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61 | /*-------------------------------------------------------------------------+ |
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62 | | Function: clockIsr |
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63 | | Description: Interrupt Service Routine for clock (0h) interruption. |
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64 | | Global Variables: Clock_driver_ticks, Clock_isrs. |
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65 | | Arguments: vector - standard RTEMS argument - see documentation. |
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66 | | Returns: standard return value - see documentation. |
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67 | +--------------------------------------------------------------------------*/ |
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68 | static void clockIsr() |
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69 | { |
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70 | /*-------------------------------------------------------------------------+ |
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71 | | PLEASE NOTE: The following is directly transcribed from the go32 BSP for |
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72 | | those who wish to use it with PENTIUM based machine. It needs |
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73 | | to be correctly integrated with the rest of the code!!! |
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74 | +--------------------------------------------------------------------------*/ |
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75 | |
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76 | #if 0 && defined(pentium) /* more accurate clock for PENTIUMs (not supported) */ |
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77 | { |
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78 | extern long long Last_RDTSC; |
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79 | __asm __volatile(".byte 0x0F, 0x31" : "=A" (Last_RDTSC)); |
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80 | } |
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81 | #endif /* 0 && pentium */ |
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82 | |
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83 | Clock_driver_ticks++; |
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84 | |
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85 | if ( Clock_isrs == 1 ) |
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86 | { |
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87 | rtems_clock_tick(); |
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88 | Clock_isrs = Clock_isrs_per_tick; |
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89 | } |
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90 | else |
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91 | Clock_isrs--; |
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92 | |
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93 | } /* clockIsr */ |
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94 | |
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95 | /*-------------------------------------------------------------------------+ |
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96 | | Function: Clock_exit |
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97 | | Description: Clock cleanup routine at RTEMS exit. NOTE: This routine is |
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98 | | not really necessary, since there will be a reset at exit. |
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99 | | Global Variables: None. |
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100 | | Arguments: None. |
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101 | | Returns: Nothing. |
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102 | +--------------------------------------------------------------------------*/ |
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103 | void clockOff(const rtems_irq_connect_data* unused) |
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104 | { |
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105 | /* reset timer mode to standard (BIOS) value */ |
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106 | outport_byte(TIMER_MODE, TIMER_SEL0 | TIMER_16BIT | TIMER_RATEGEN); |
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107 | outport_byte(TIMER_CNTR0, 0); |
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108 | outport_byte(TIMER_CNTR0, 0); |
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109 | } /* Clock_exit */ |
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110 | |
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111 | /*-------------------------------------------------------------------------+ |
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112 | | Function: Install_clock |
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113 | | Description: Initialize and install clock interrupt handler. |
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114 | | Global Variables: None. |
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115 | | Arguments: None. |
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116 | | Returns: Nothing. |
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117 | +--------------------------------------------------------------------------*/ |
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118 | static void clockOn(const rtems_irq_connect_data* unused) |
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119 | { |
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120 | uint32_t microseconds_per_isr; |
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121 | |
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122 | #if 0 |
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123 | /* Initialize clock from on-board real time clock. This breaks the */ |
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124 | /* test code which assumes which assumes the application will do it. */ |
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125 | { |
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126 | rtems_time_of_day now; |
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127 | |
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128 | /* External Prototypes */ |
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129 | extern void init_rtc(void); /* defined in 'rtc.c' */ |
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130 | extern long rtc_read(rtems_time_of_day *); /* defined in 'rtc.c' */ |
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131 | |
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132 | init_rtc(); |
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133 | if (rtc_read(&now) >= 0) |
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134 | clock_set(&now); |
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135 | } |
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136 | #endif /* 0 */ |
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137 | |
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138 | /* Start by assuming hardware counter is large enough, then scale it until |
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139 | it actually fits. */ |
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140 | |
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141 | Clock_driver_ticks = 0; |
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142 | Clock_isrs_per_tick = 1; |
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143 | |
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144 | if (rtems_configuration_get_microseconds_per_tick() == 0) |
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145 | microseconds_per_isr = 10000; /* default 10 ms */ |
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146 | else |
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147 | microseconds_per_isr = rtems_configuration_get_microseconds_per_tick(); |
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148 | while (US_TO_TICK(microseconds_per_isr) > 65535) |
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149 | { |
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150 | Clock_isrs_per_tick *= 10; |
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151 | microseconds_per_isr /= 10; |
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152 | } |
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153 | |
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154 | Clock_isrs = Clock_isrs_per_tick; /* Initialize Clock_isrs */ |
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155 | |
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156 | { |
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157 | /* 105/88 approximates TIMER_TICK * 1e-6 */ |
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158 | uint32_t count = US_TO_TICK(microseconds_per_isr); |
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159 | |
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160 | outport_byte(TIMER_MODE, TIMER_SEL0|TIMER_16BIT|TIMER_RATEGEN); |
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161 | outport_byte(TIMER_CNTR0, count >> 0 & 0xff); |
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162 | outport_byte(TIMER_CNTR0, count >> 8 & 0xff); |
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163 | } |
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164 | |
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165 | } |
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166 | |
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167 | int clockIsOn(const rtems_irq_connect_data* unused) |
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168 | { |
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169 | return ((i8259s_cache & 0x1) == 0); |
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170 | } |
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171 | |
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172 | static rtems_irq_connect_data clockIrqData = {BSP_PERIODIC_TIMER, |
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173 | clockIsr, |
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174 | 0, |
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175 | clockOn, |
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176 | clockOff, |
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177 | clockIsOn}; |
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178 | |
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179 | /*-------------------------------------------------------------------------+ |
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180 | | Clock device driver INITIALIZE entry point. |
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181 | +--------------------------------------------------------------------------+ |
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182 | | Initilizes the clock driver. |
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183 | +--------------------------------------------------------------------------*/ |
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184 | rtems_device_driver |
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185 | Clock_initialize(rtems_device_major_number major, |
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186 | rtems_device_minor_number minor, |
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187 | void *pargp) |
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188 | { |
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189 | |
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190 | if (!BSP_install_rtems_irq_handler (&clockIrqData)) { |
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191 | printk("Unable to initialize system clock\n"); |
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192 | rtems_fatal_error_occurred(1); |
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193 | } |
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194 | /* make major/minor avail to others such as shared memory driver */ |
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195 | |
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196 | rtems_clock_major = major; |
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197 | rtems_clock_minor = minor; |
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198 | |
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199 | return RTEMS_SUCCESSFUL; |
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200 | } /* Clock_initialize */ |
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201 | |
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202 | /*-------------------------------------------------------------------------+ |
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203 | | Console device driver CONTROL entry point |
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204 | +--------------------------------------------------------------------------*/ |
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205 | rtems_device_driver |
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206 | Clock_control(rtems_device_major_number major, |
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207 | rtems_device_minor_number minor, |
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208 | void *pargp) |
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209 | { |
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210 | if (pargp != NULL) |
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211 | { |
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212 | rtems_libio_ioctl_args_t *args = pargp; |
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213 | |
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214 | /*-------------------------------------------------------------------------+ |
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215 | | This is hokey, but until we get a defined interface to do this, it will |
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216 | | just be this simple... |
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217 | +-------------------------------------------------------------------------*/ |
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218 | |
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219 | if (args->command == rtems_build_name('I', 'S', 'R', ' ')) |
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220 | clockIsr(); |
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221 | else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) |
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222 | { |
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223 | if (!BSP_install_rtems_irq_handler (&clockIrqData)) { |
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224 | printk("Error installing clock interrupt handler!\n"); |
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225 | rtems_fatal_error_occurred(1); |
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226 | } |
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227 | } |
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228 | } |
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229 | |
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230 | return RTEMS_SUCCESSFUL; |
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231 | } /* Clock_control */ |
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232 | |
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233 | void Clock_exit() |
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234 | { |
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235 | BSP_remove_rtems_irq_handler (&clockIrqData); |
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236 | } |
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237 | |
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