1 | /* |
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2 | * This routine initializes the MC68340/349 Periodic Interval Timer |
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3 | * |
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4 | * Based on the `gen68360' board support package, and covered by the |
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5 | * original distribution terms. |
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6 | * |
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7 | * Geoffroy Montel |
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8 | * France Telecom - CNET/DSM/TAM/CAT |
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9 | * 4, rue du Clos Courtel |
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10 | * 35512 CESSON-SEVIGNE |
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11 | * FRANCE |
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12 | * |
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13 | * e-mail: g_montel@yahoo.com |
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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 | /* |
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19 | * Input parameters: NONE |
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20 | * |
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21 | * Output parameters: NONE |
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22 | * |
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23 | * COPYRIGHT (c) 1989-1999. |
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24 | * On-Line Applications Research Corporation (OAR). |
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25 | * |
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26 | * The license and distribution terms for this file may be |
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27 | * found in the file LICENSE in this distribution or at |
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28 | * http://www.OARcorp.com/rtems/license.html. |
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29 | */ |
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30 | |
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31 | #include <stdlib.h> /* for atexit() */ |
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32 | #include <bsp.h> |
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33 | #include <rtems/libio.h> |
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34 | #include <m68340.h> |
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35 | |
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36 | #define CLOCK_VECTOR 120 /* clock isr routine vector in the vbr */ |
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37 | #define CLOCK_IRQ_LEVEL 6 /* clock isr level */ |
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38 | |
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39 | /* |
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40 | * Clock_driver_ticks is a monotonically increasing counter of the |
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41 | * number of clock ticks since the driver was initialized. |
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42 | */ |
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43 | volatile rtems_unsigned32 Clock_driver_ticks; |
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44 | |
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45 | /* |
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46 | * These are set by clock driver during its init |
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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 | /* |
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52 | * Periodic interval timer interrupt handler |
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53 | */ |
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54 | |
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55 | /****************************************************** |
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56 | Name: Clock_isr |
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57 | Input parameters: irq vector |
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58 | Output parameters: none |
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59 | Description: update # of clock ticks |
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60 | *****************************************************/ |
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61 | rtems_isr |
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62 | Clock_isr (rtems_vector_number vector) |
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63 | { |
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64 | /* |
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65 | * Announce the clock tick |
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66 | */ |
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67 | Clock_driver_ticks++; |
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68 | rtems_clock_tick(); |
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69 | } |
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70 | |
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71 | /****************************************************** |
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72 | Name: clock_exit |
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73 | Input parameters: - |
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74 | Output parameters: - |
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75 | Description: turn off periodic time at shutdown |
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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 | /* |
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81 | * Turn off periodic interval timer |
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82 | */ |
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83 | SIMPITR = 0; |
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84 | } |
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85 | |
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86 | /****************************************************** |
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87 | Name: Install_clock |
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88 | Input parameters: the Clock Interrupt Subroutine |
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89 | Output parameters: - |
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90 | Description: initialize the periodic interval ticker |
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91 | called by Clock_Initialize |
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92 | *****************************************************/ |
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93 | static void |
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94 | Install_clock (rtems_isr_entry clock_isr) |
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95 | { |
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96 | unsigned32 pitr_tmp; |
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97 | unsigned32 usecs_per_tick; |
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98 | |
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99 | Clock_driver_ticks = 0; |
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100 | |
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101 | set_vector (clock_isr, CLOCK_VECTOR, 1); |
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102 | |
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103 | /* sets the Periodic Interrupt Control Register PICR */ |
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104 | /* voir a quoi correspond exactement le Clock Vector */ |
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105 | |
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106 | SIMPICR = ( CLOCK_IRQ_LEVEL << 8 ) | ( CLOCK_VECTOR ); |
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107 | |
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108 | /* sets the PITR count value */ |
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109 | /* this assumes a 32.765 kHz crystal */ |
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110 | |
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111 | usecs_per_tick = BSP_Configuration.microseconds_per_tick; |
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112 | /* find out whether prescaler should be enabled or not */ |
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113 | if ( usecs_per_tick <= 31128 ) { |
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114 | pitr_tmp = ( usecs_per_tick * 8192 ) / 1000000 ; |
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115 | } else { |
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116 | pitr_tmp = ( usecs_per_tick / 1000000 ) * 16; |
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117 | /* enable it */ |
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118 | pitr_tmp |= 0x100; |
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119 | } |
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120 | |
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121 | SIMPITR = (unsigned char) pitr_tmp; |
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122 | |
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123 | atexit (Clock_exit); |
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124 | } |
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125 | |
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126 | /****************************************************** |
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127 | Name: Clock_initialize |
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128 | Input parameters: major & minor numbers |
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129 | Output parameters: - |
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130 | Description: main entry for clock initialization |
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131 | calls the bsp dependant routine |
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132 | *****************************************************/ |
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133 | rtems_device_driver |
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134 | Clock_initialize( |
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135 | 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 | { |
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140 | Install_clock (Clock_isr); |
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141 | |
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142 | /* |
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143 | * make major/minor avail to others such as shared memory driver |
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144 | */ |
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145 | rtems_clock_major = major; |
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146 | rtems_clock_minor = minor; |
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147 | |
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148 | return RTEMS_SUCCESSFUL; |
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149 | } |
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150 | |
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151 | /****************************************************** |
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152 | Name: Clock_control |
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153 | Input parameters: major & minor number |
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154 | Output parameters: |
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155 | Description: |
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156 | *****************************************************/ |
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157 | rtems_device_driver Clock_control( |
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158 | rtems_device_major_number major, |
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159 | rtems_device_minor_number minor, |
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160 | void *pargp |
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161 | ) |
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162 | { |
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163 | rtems_unsigned32 isrlevel; |
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164 | rtems_libio_ioctl_args_t *args = pargp; |
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165 | |
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166 | if (args) { |
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167 | /* |
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168 | * This is hokey, but until we get a defined interface |
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169 | * to do this, it will just be this simple... |
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170 | */ |
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171 | if (args->command == rtems_build_name('I', 'S', 'R', ' ')) { |
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172 | Clock_isr( CLOCK_VECTOR); |
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173 | } |
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174 | else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) { |
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175 | rtems_interrupt_disable( isrlevel ); |
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176 | (void) set_vector( args->buffer, CLOCK_VECTOR, 1 ); |
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177 | rtems_interrupt_enable( isrlevel ); |
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178 | } |
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179 | } |
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180 | return RTEMS_SUCCESSFUL; |
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181 | } |
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