1 | /* |
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2 | * Clock Driver for MCF5206eLITE board |
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3 | * |
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4 | * This driver initailizes timer1 on the MCF5206E as the |
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5 | * main system clock |
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6 | * |
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7 | * Author: Victor V. Vengerov <vvv@oktet.ru> |
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8 | * |
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9 | * Based on work: |
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10 | * David Fiddes, D.J@fiddes.surfaid.org |
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11 | * http://www.calm.hw.ac.uk/davidf/coldfire/ |
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12 | * |
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13 | * COPYRIGHT (c) 1989-1998. |
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14 | * On-Line Applications Research Corporation (OAR). |
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15 | * Copyright assigned to U.S. Government, 1994. |
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16 | * |
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17 | * The license and distribution terms for this file may be |
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18 | * found in the file LICENSE in this distribution or at |
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19 | * |
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20 | * http://www.OARcorp.com/rtems/license.html. |
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21 | * |
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22 | * $Id$ |
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23 | */ |
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24 | |
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25 | #include <stdlib.h> |
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26 | #include <bsp.h> |
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27 | #include <rtems/libio.h> |
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28 | #include "mcf5206/mcf5206e.h" |
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29 | |
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30 | /* |
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31 | * Clock_driver_ticks is a monotonically increasing counter of the |
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32 | * number of clock ticks since the driver was initialized. |
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33 | */ |
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34 | volatile rtems_unsigned32 Clock_driver_ticks; |
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35 | |
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36 | |
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37 | /* |
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38 | * These are set by clock driver during its init |
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39 | */ |
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40 | |
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41 | rtems_device_major_number rtems_clock_major = ~0; |
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42 | rtems_device_minor_number rtems_clock_minor; |
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43 | |
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44 | rtems_isr (*rtems_clock_hook)(rtems_vector_number) = NULL; |
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45 | |
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46 | /* Clock_isr -- |
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47 | * This handles the timer interrupt by clearing the timer's interrupt |
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48 | * flag and announcing the clock tick to the system. |
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49 | * |
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50 | * PARAMETERS: |
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51 | * vector - timer interrupt vector number |
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52 | * |
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53 | * RETURNS: |
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54 | * none |
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55 | */ |
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56 | rtems_isr |
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57 | Clock_isr (rtems_vector_number vector) |
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58 | { |
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59 | /* Clear pending interrupt... */ |
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60 | *MCF5206E_TER(MBAR,1) = MCF5206E_TER_REF | MCF5206E_TER_CAP; |
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61 | |
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62 | /* Announce the clock tick */ |
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63 | Clock_driver_ticks++; |
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64 | rtems_clock_tick(); |
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65 | if (rtems_clock_hook != NULL) |
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66 | rtems_clock_hook(vector); |
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67 | } |
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68 | |
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69 | |
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70 | /* Clock_exit -- |
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71 | * This shuts down the timer if it was enabled and removes it |
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72 | * from the MCF5206E interrupt mask. |
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73 | * |
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74 | * PARAMETERS: |
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75 | * none |
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76 | * |
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77 | * RETURNS: |
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78 | * none |
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79 | */ |
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80 | void |
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81 | Clock_exit(void) |
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82 | { |
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83 | if (BSP_Configuration.ticks_per_timeslice) |
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84 | { |
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85 | /* disable all timer1 interrupts */ |
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86 | *MCF5206E_IMR(MBAR) |= MCF5206E_INTR_BIT(MCF5206E_INTR_TIMER_1); |
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87 | |
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88 | /* reset timer1 */ |
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89 | *MCF5206E_TMR(MBAR,1) = MCF5206E_TMR_ICLK_STOP; |
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90 | |
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91 | /* clear pending */ |
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92 | *MCF5206E_TER(MBAR,1) = MCF5206E_TER_REF | MCF5206E_TER_CAP; |
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93 | } |
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94 | } |
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95 | |
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96 | |
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97 | /* Install_clock -- |
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98 | * This initialises timer1 with the BSP timeslice config value |
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99 | * as a reference and sets up the interrupt handler for clock ticks. |
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100 | * |
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101 | * PARAMETERS: |
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102 | * clock_isr - clock interrupt handler routine |
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103 | * |
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104 | * RETURNS: |
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105 | * none. |
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106 | */ |
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107 | static void |
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108 | Install_clock(rtems_isr_entry clock_isr) |
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109 | { |
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110 | Clock_driver_ticks = 0; |
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111 | if (BSP_Configuration.ticks_per_timeslice) |
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112 | { |
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113 | /* Configure timer1 interrupts */ |
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114 | *MCF5206E_ICR(MBAR,MCF5206E_INTR_TIMER_1) = |
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115 | MCF5206E_ICR_AVEC | |
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116 | ((BSP_INTLVL_TIMER1 << MCF5206E_ICR_IL_S) & MCF5206E_ICR_IL) | |
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117 | ((BSP_INTPRIO_TIMER1 << MCF5206E_ICR_IP_S) & MCF5206E_ICR_IP); |
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118 | |
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119 | /* Register the interrupt handler */ |
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120 | set_vector(clock_isr, BSP_INTVEC_TIMER1, 1); |
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121 | |
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122 | /* Reset timer 1 */ |
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123 | *MCF5206E_TMR(MBAR, 1) = MCF5206E_TMR_RST; |
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124 | *MCF5206E_TMR(MBAR, 1) = MCF5206E_TMR_ICLK_STOP; |
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125 | *MCF5206E_TMR(MBAR, 1) = MCF5206E_TMR_RST; |
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126 | *MCF5206E_TCN(MBAR, 1) = 0; /* Reset counter */ |
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127 | *MCF5206E_TER(MBAR, 1) = MCF5206E_TER_REF | MCF5206E_TER_CAP; |
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128 | |
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129 | /* Set Timer 1 prescaler so that it counts in microseconds */ |
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130 | *MCF5206E_TMR(MBAR, 1) = |
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131 | (((BSP_SYSTEM_FREQUENCY/1000000 - 1) << MCF5206E_TMR_PS_S) & |
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132 | MCF5206E_TMR_PS) | |
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133 | MCF5206E_TMR_CE_NONE | MCF5206E_TMR_ORI | MCF5206E_TMR_FRR | |
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134 | MCF5206E_TMR_RST; |
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135 | |
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136 | /* Set the timer timeout value from the BSP config */ |
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137 | *MCF5206E_TRR(MBAR, 1) = BSP_Configuration.microseconds_per_tick - 1; |
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138 | |
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139 | /* Feed system frequency to the timer */ |
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140 | *MCF5206E_TMR(MBAR, 1) |= MCF5206E_TMR_ICLK_MSCLK; |
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141 | |
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142 | /* Enable timer 1 interrupts */ |
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143 | *MCF5206E_IMR(MBAR) &= ~MCF5206E_INTR_BIT(MCF5206E_INTR_TIMER_1); |
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144 | |
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145 | /* Register the driver exit procedure so we can shutdown */ |
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146 | atexit(Clock_exit); |
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147 | } |
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148 | } |
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149 | |
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150 | |
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151 | /* Clock_initialize -- |
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152 | * This is called to setup the clock driver. It calls the hardware |
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153 | * setup function and make the driver major/minor values available |
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154 | * for other. |
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155 | * |
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156 | * PARAMETERS: |
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157 | * major - clock device major number |
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158 | * minor - clock device minor number |
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159 | * pargp - device driver initialization argument (not used) |
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160 | * |
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161 | * RETURNS: |
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162 | * RTEMS status code |
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163 | */ |
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164 | rtems_device_driver |
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165 | Clock_initialize(rtems_device_major_number major, |
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166 | rtems_device_minor_number minor, |
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167 | void *pargp) |
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168 | { |
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169 | Install_clock (Clock_isr); |
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170 | |
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171 | /* Make major/minor avail to others such as shared memory driver */ |
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172 | rtems_clock_major = major; |
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173 | rtems_clock_minor = minor; |
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174 | |
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175 | return RTEMS_SUCCESSFUL; |
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176 | } |
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177 | |
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178 | |
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179 | /* Clock_control -- |
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180 | * I/O control (IOCTL) function for Clock driver. At this moment this |
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181 | * just runs the interrupt handler or re-registers the interrupt handler |
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182 | * on request. |
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183 | * |
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184 | * PARAMETERS: |
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185 | * major - clock major device number |
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186 | * minor - clock minor device number |
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187 | * pargp - pointer to IOCTL arguments |
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188 | * |
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189 | * RETURNS: |
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190 | * RTEMS status code |
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191 | */ |
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192 | rtems_device_driver |
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193 | Clock_control(rtems_device_major_number major, |
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194 | rtems_device_minor_number minor, |
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195 | void *pargp) |
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196 | { |
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197 | rtems_unsigned32 isrlevel; |
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198 | rtems_libio_ioctl_args_t *args = pargp; |
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199 | |
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200 | if (args) |
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201 | { |
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202 | /* |
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203 | * This is hokey, but until we get a defined interface |
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204 | * to do this, it will just be this simple... |
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205 | */ |
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206 | if (args->command == rtems_build_name('I', 'S', 'R', ' ')) |
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207 | { |
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208 | Clock_isr(BSP_INTVEC_TIMER1); |
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209 | } |
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210 | else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) |
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211 | { |
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212 | rtems_interrupt_disable( isrlevel ); |
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213 | (void) set_vector( args->buffer, BSP_INTVEC_TIMER1, 1 ); |
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214 | rtems_interrupt_enable( isrlevel ); |
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215 | } |
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216 | } |
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217 | return RTEMS_SUCCESSFUL; |
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218 | } |
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