1 | /*
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2 | * Copyright (C) 2005 Jakub Jermar
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3 | * All rights reserved.
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4 | *
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5 | * Redistribution and use in source and binary forms, with or without
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6 | * modification, are permitted provided that the following conditions
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7 | * are met:
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8 | *
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9 | * - Redistributions of source code must retain the above copyright
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10 | * notice, this list of conditions and the following disclaimer.
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11 | * - Redistributions in binary form must reproduce the above copyright
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12 | * notice, this list of conditions and the following disclaimer in the
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13 | * documentation and/or other materials provided with the distribution.
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14 | * - The name of the author may not be used to endorse or promote products
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15 | * derived from this software without specific prior written permission.
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16 | *
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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27 | */
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28 |
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29 | /** @addtogroup ia64
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30 | * @{
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31 | */
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32 | /** @file
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33 | */
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34 |
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35 | /** Interval Timer driver. */
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36 |
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37 | #include <arch/drivers/it.h>
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38 | #include <arch/ski/ski.h>
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39 | #include <arch/interrupt.h>
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40 | #include <arch/register.h>
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41 | #include <arch/asm.h>
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42 | #include <arch/barrier.h>
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43 | #include <time/clock.h>
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44 | #include <arch.h>
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45 |
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46 |
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47 | #define IT_SERVICE_CLOCKS 64
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48 |
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49 | /** Initialize Interval Timer. */
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50 | void it_init(void)
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51 | {
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52 | cr_itv_t itv;
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53 |
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54 | /* initialize Interval Timer external interrupt vector */
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55 | itv.value = itv_read();
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56 | itv.vector = INTERRUPT_TIMER;
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57 | itv.m = 0;
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58 | itv_write(itv.value);
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59 |
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60 | /* set Interval Timer Counter to zero */
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61 | itc_write(0);
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62 |
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63 | /* generate first Interval Timer interrupt in IT_DELTA ticks */
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64 | itm_write(IT_DELTA);
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65 |
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66 | /* propagate changes */
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67 | srlz_d();
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68 | }
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69 |
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70 |
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71 | /** Process Interval Timer interrupt. */
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72 | void it_interrupt(void)
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73 | {
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74 | int64_t c;
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75 | int64_t m;
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76 |
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77 | eoi_write(EOI);
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78 |
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79 | m=itm_read();
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80 |
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81 | while(1)
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82 | {
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83 |
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84 | c=itc_read();
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85 | c+=IT_SERVICE_CLOCKS;
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86 |
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87 | m+=IT_DELTA;
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88 | if(m-c<0)
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89 | {
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90 | CPU->missed_clock_ticks++;
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91 | }
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92 | else break;
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93 | }
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94 |
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95 | itm_write(m);
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96 | srlz_d(); /* propagate changes */
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97 |
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98 |
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99 |
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100 | clock();
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101 | poll_keyboard();
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102 | }
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103 |
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104 | /** @}
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105 | */
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106 |
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