1 | /* Clock |
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2 | * |
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3 | * This routine generates clock ticks using standard POSIX services. |
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4 | * The tick frequency is specified by the bsp. |
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5 | * |
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6 | * COPYRIGHT (c) 1989-1999. |
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7 | * On-Line Applications Research Corporation (OAR). |
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8 | * |
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9 | * The license and distribution terms for this file may be |
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10 | * found in the file LICENSE in this distribution or at |
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11 | * http://www.OARcorp.com/rtems/license.html. |
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12 | * |
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13 | * $Id$ |
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14 | */ |
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15 | |
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16 | #include <bsp.h> |
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17 | #include <rtems/libio.h> |
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18 | #include <stdlib.h> |
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19 | |
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20 | void Clock_exit(void); |
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21 | |
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22 | volatile rtems_unsigned32 Clock_driver_ticks; |
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23 | |
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24 | rtems_unsigned32 Clock_driver_vector; |
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25 | |
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26 | /* |
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27 | * These are set by clock driver during its init |
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28 | */ |
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29 | |
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30 | rtems_device_major_number rtems_clock_major = ~0; |
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31 | rtems_device_minor_number rtems_clock_minor; |
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32 | |
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33 | void Install_clock(rtems_isr_entry clock_isr) |
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34 | { |
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35 | Clock_driver_ticks = 0; |
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36 | |
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37 | (void) set_vector( clock_isr, Clock_driver_vector, 1 ); |
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38 | |
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39 | _CPU_Start_clock( BSP_Configuration.microseconds_per_tick ); |
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40 | |
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41 | atexit(Clock_exit); |
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42 | } |
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43 | |
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44 | void Clock_isr(int vector) |
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45 | { |
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46 | Clock_driver_ticks++; |
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47 | rtems_clock_tick(); |
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48 | } |
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49 | |
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50 | /* |
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51 | * Called via atexit() |
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52 | * Remove the clock signal |
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53 | */ |
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54 | |
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55 | void Clock_exit(void) |
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56 | { |
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57 | _CPU_Stop_clock(); |
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58 | |
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59 | (void) set_vector( 0, Clock_driver_vector, 1 ); |
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60 | } |
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61 | |
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62 | rtems_device_driver Clock_initialize( |
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63 | rtems_device_major_number major, |
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64 | rtems_device_minor_number minor, |
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65 | void *pargp |
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66 | ) |
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67 | { |
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68 | Clock_driver_vector = _CPU_Get_clock_vector(); |
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69 | |
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70 | Install_clock((rtems_isr_entry) Clock_isr); |
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71 | |
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72 | /* |
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73 | * make major/minor avail to others such as shared memory driver |
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74 | */ |
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75 | rtems_clock_major = major; |
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76 | rtems_clock_minor = minor; |
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77 | |
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78 | return RTEMS_SUCCESSFUL; |
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79 | } |
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80 | |
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81 | rtems_device_driver Clock_control( |
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82 | rtems_device_major_number major, |
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83 | rtems_device_minor_number minor, |
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84 | void *pargp |
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85 | ) |
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86 | { |
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87 | rtems_unsigned32 isrlevel; |
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88 | rtems_libio_ioctl_args_t *args = pargp; |
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89 | |
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90 | if (args == 0) |
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91 | goto done; |
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92 | |
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93 | /* |
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94 | * This is hokey, but until we get a defined interface |
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95 | * to do this, it will just be this simple... |
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96 | */ |
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97 | |
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98 | if (args->command == rtems_build_name('I', 'S', 'R', ' ')) |
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99 | { |
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100 | Clock_isr(Clock_driver_vector); |
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101 | } |
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102 | else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) |
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103 | { |
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104 | rtems_interrupt_disable( isrlevel ); |
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105 | (void) set_vector( args->buffer, Clock_driver_vector, 1 ); |
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106 | rtems_interrupt_enable( isrlevel ); |
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107 | } |
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108 | |
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109 | done: |
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110 | return RTEMS_SUCCESSFUL; |
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111 | } |
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