[b94554f] | 1 | /* |
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| 2 | * Clock Tick Device Driver Shell |
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| 3 | * |
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[6083017] | 4 | * COPYRIGHT (c) 1989-2009. |
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[b94554f] | 5 | * On-Line Applications Research Corporation (OAR). |
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| 6 | * |
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| 7 | * The license and distribution terms for this file may be |
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| 8 | * found in the file LICENSE in this distribution or at |
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| 9 | * http://www.rtems.com/license/LICENSE. |
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| 10 | * |
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| 11 | * $Id$ |
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| 12 | */ |
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| 13 | |
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| 14 | #include <stdlib.h> |
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| 15 | |
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| 16 | #include <bsp.h> |
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| 17 | |
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| 18 | #if defined(CLOCK_DRIVER_USE_FAST_IDLE) && defined(CLOCK_DRIVER_ISRS_PER_TICK) |
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| 19 | #error "clockdrv_shell.c: fast idle and N ISRs per tick is not supported" |
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| 20 | #endif |
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| 21 | |
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| 22 | /* |
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| 23 | * This method is rarely used so default it. |
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| 24 | */ |
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| 25 | #ifndef Clock_driver_support_find_timer |
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[f1e8903] | 26 | #define Clock_driver_support_find_timer() |
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[b94554f] | 27 | #endif |
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| 28 | |
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| 29 | /* |
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| 30 | * ISRs until next clock tick |
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| 31 | */ |
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| 32 | #ifdef CLOCK_DRIVER_ISRS_PER_TICK |
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[f1e8903] | 33 | volatile uint32_t Clock_driver_isrs; |
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[b94554f] | 34 | #endif |
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| 35 | |
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| 36 | /* |
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| 37 | * Clock ticks since initialization |
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| 38 | */ |
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[6083017] | 39 | volatile uint32_t Clock_driver_ticks; |
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[b94554f] | 40 | |
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| 41 | void Clock_exit( void ); |
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| 42 | |
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| 43 | /* |
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| 44 | * Clock_isr |
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| 45 | * |
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| 46 | * This is the clock tick interrupt handler. |
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| 47 | * |
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| 48 | * Input parameters: |
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| 49 | * vector - vector number |
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| 50 | * |
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| 51 | * Output parameters: NONE |
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| 52 | * |
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| 53 | * Return values: NONE |
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| 54 | */ |
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| 55 | rtems_isr Clock_isr( |
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| 56 | rtems_vector_number vector |
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| 57 | ) |
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| 58 | { |
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| 59 | /* |
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| 60 | * Accurate count of ISRs |
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| 61 | */ |
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| 62 | Clock_driver_ticks += 1; |
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| 63 | |
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[f1e8903] | 64 | #ifdef CLOCK_DRIVER_USE_FAST_IDLE |
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| 65 | do { |
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| 66 | rtems_clock_tick(); |
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| 67 | } while ( _Thread_Executing == _Thread_Idle && |
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| 68 | _Thread_Heir == _Thread_Executing); |
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| 69 | |
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| 70 | Clock_driver_support_at_tick(); |
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| 71 | return; |
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| 72 | #else |
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| 73 | /* |
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| 74 | * Do the hardware specific per-tick action. |
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| 75 | * |
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| 76 | * The counter/timer may or may not be set to automatically reload. |
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| 77 | */ |
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| 78 | Clock_driver_support_at_tick(); |
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| 79 | |
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| 80 | #ifdef CLOCK_DRIVER_ISRS_PER_TICK |
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| 81 | /* |
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| 82 | * The driver is multiple ISRs per clock tick. |
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| 83 | */ |
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| 84 | if ( !Clock_driver_isrs ) { |
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| 85 | rtems_clock_tick(); |
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| 86 | |
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| 87 | Clock_driver_isrs = CLOCK_DRIVER_ISRS_PER_TICK; |
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| 88 | } |
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| 89 | Clock_driver_isrs--; |
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| 90 | #else |
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| 91 | /* |
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| 92 | * The driver is one ISR per clock tick. |
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| 93 | */ |
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| 94 | rtems_clock_tick(); |
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| 95 | #endif |
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| 96 | #endif |
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[b94554f] | 97 | } |
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| 98 | |
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| 99 | /* |
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| 100 | * Clock_exit |
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| 101 | * |
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| 102 | * This routine allows the clock driver to exit by masking the interrupt and |
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| 103 | * disabling the clock's counter. |
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| 104 | * |
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| 105 | * Input parameters: NONE |
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| 106 | * |
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| 107 | * Output parameters: NONE |
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| 108 | * |
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| 109 | * Return values: NONE |
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| 110 | * |
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| 111 | */ |
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| 112 | |
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| 113 | void Clock_exit( void ) |
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| 114 | { |
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| 115 | Clock_driver_support_shutdown_hardware(); |
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| 116 | |
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| 117 | /* do not restore old vector */ |
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| 118 | } |
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| 119 | |
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| 120 | /* |
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| 121 | * Clock_initialize |
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| 122 | * |
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| 123 | * This routine initializes the clock driver. |
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| 124 | * |
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| 125 | * Input parameters: |
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| 126 | * major - clock device major number |
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| 127 | * minor - clock device minor number |
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| 128 | * parg - pointer to optional device driver arguments |
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| 129 | * |
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| 130 | * Output parameters: NONE |
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| 131 | * |
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| 132 | * Return values: |
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| 133 | * rtems_device_driver status code |
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| 134 | */ |
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| 135 | |
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| 136 | rtems_device_driver Clock_initialize( |
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| 137 | rtems_device_major_number major, |
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| 138 | rtems_device_minor_number minor, |
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| 139 | void *pargp |
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| 140 | ) |
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| 141 | { |
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[6083017] | 142 | rtems_isr_entry Old_ticker; |
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| 143 | |
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| 144 | Clock_driver_ticks = 0; |
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| 145 | |
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| 146 | /* |
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| 147 | * Find timer -- some BSPs search buses for hardware timer |
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| 148 | */ |
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| 149 | Clock_driver_support_find_timer(); |
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| 150 | |
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| 151 | /* |
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| 152 | * Install vector |
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| 153 | */ |
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| 154 | Clock_driver_support_install_isr( Clock_isr, Old_ticker ); |
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| 155 | |
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| 156 | #if defined(Clock_driver_nanoseconds_since_last_tick) |
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| 157 | rtems_clock_set_nanoseconds_extension( |
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| 158 | Clock_driver_nanoseconds_since_last_tick |
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| 159 | ); |
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| 160 | #endif |
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| 161 | |
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| 162 | /* |
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| 163 | * Now initialize the hardware that is the source of the tick ISR. |
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| 164 | */ |
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| 165 | Clock_driver_support_initialize_hardware(); |
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| 166 | |
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| 167 | atexit( Clock_exit ); |
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[b94554f] | 168 | |
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| 169 | /* |
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| 170 | * If we are counting ISRs per tick, then initialize the counter. |
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| 171 | */ |
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[f1e8903] | 172 | #ifdef CLOCK_DRIVER_ISRS_PER_TICK |
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| 173 | Clock_driver_isrs = CLOCK_DRIVER_ISRS_PER_TICK; |
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| 174 | #endif |
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[b94554f] | 175 | |
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| 176 | return RTEMS_SUCCESSFUL; |
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| 177 | } |
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