[b94554f] | 1 | /* |
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| 2 | * Clock Tick Device Driver Shell |
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| 3 | * |
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| 4 | * COPYRIGHT (c) 1989-2006. |
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| 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 | /* |
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| 24 | * This method is rarely used so default it. |
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| 25 | */ |
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| 26 | #ifndef Clock_driver_support_find_timer |
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| 27 | #define Clock_driver_support_find_timer() |
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| 28 | #endif |
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| 29 | |
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| 30 | /* |
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| 31 | * ISRs until next clock tick |
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| 32 | */ |
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| 33 | |
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| 34 | #ifdef CLOCK_DRIVER_ISRS_PER_TICK |
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| 35 | volatile uint32_t Clock_driver_isrs; |
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| 36 | #endif |
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| 37 | |
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| 38 | /* |
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| 39 | * Clock ticks since initialization |
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| 40 | */ |
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| 41 | |
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| 42 | volatile uint32_t Clock_driver_ticks; |
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| 43 | |
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| 44 | /* |
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| 45 | * ISR formerly installed. |
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| 46 | */ |
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| 47 | |
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| 48 | rtems_isr_entry Old_ticker; |
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| 49 | |
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| 50 | void Clock_exit( void ); |
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| 51 | |
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| 52 | /* |
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| 53 | * Major and minor number. |
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| 54 | */ |
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| 55 | |
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| 56 | rtems_device_major_number rtems_clock_major = UINT32_MAX; |
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| 57 | rtems_device_minor_number rtems_clock_minor; |
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| 58 | |
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| 59 | /* |
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| 60 | * Clock_isr |
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| 61 | * |
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| 62 | * This is the clock tick interrupt handler. |
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| 63 | * |
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| 64 | * Input parameters: |
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| 65 | * vector - vector number |
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| 66 | * |
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| 67 | * Output parameters: NONE |
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| 68 | * |
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| 69 | * Return values: NONE |
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| 70 | * |
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| 71 | */ |
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| 72 | |
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| 73 | rtems_isr Clock_isr( |
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| 74 | rtems_vector_number vector |
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| 75 | ) |
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| 76 | { |
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| 77 | /* |
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| 78 | * Accurate count of ISRs |
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| 79 | */ |
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| 80 | |
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| 81 | Clock_driver_ticks += 1; |
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| 82 | |
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| 83 | #ifdef CLOCK_DRIVER_USE_FAST_IDLE |
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| 84 | do { |
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| 85 | rtems_clock_tick(); |
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| 86 | } while ( _Thread_Executing == _Thread_Idle && |
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| 87 | _Thread_Heir == _Thread_Executing); |
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| 88 | |
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| 89 | Clock_driver_support_at_tick(); |
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| 90 | return; |
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| 91 | |
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| 92 | #else |
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| 93 | |
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| 94 | /* |
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| 95 | * Do the hardware specific per-tick action. |
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| 96 | * |
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| 97 | * The counter/timer may or may not be set to automatically reload. |
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| 98 | */ |
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| 99 | |
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| 100 | Clock_driver_support_at_tick(); |
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| 101 | |
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| 102 | #ifdef CLOCK_DRIVER_ISRS_PER_TICK |
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| 103 | /* |
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| 104 | * The driver is multiple ISRs per clock tick. |
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| 105 | */ |
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| 106 | |
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| 107 | if ( !Clock_driver_isrs ) { |
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| 108 | |
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| 109 | rtems_clock_tick(); |
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| 110 | |
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| 111 | Clock_driver_isrs = CLOCK_DRIVER_ISRS_PER_TICK; |
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| 112 | } |
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| 113 | Clock_driver_isrs--; |
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| 114 | #else |
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| 115 | |
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| 116 | /* |
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| 117 | * The driver is one ISR per clock tick. |
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| 118 | */ |
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| 119 | rtems_clock_tick(); |
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| 120 | #endif |
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| 121 | #endif |
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| 122 | } |
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| 123 | |
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| 124 | /* |
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| 125 | * Install_clock |
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| 126 | * |
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| 127 | * This routine actually performs the hardware initialization for the clock. |
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| 128 | * |
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| 129 | * Input parameters: |
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| 130 | * clock_isr - clock interrupt service routine entry point |
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| 131 | * |
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| 132 | * Output parameters: NONE |
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| 133 | * |
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| 134 | * Return values: NONE |
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| 135 | * |
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| 136 | */ |
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| 137 | |
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| 138 | static void Install_clock( |
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| 139 | rtems_isr_entry clock_isr |
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| 140 | ) |
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| 141 | { |
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| 142 | Clock_driver_ticks = 0; |
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| 143 | |
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| 144 | /* |
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| 145 | * Find timer -- some BSPs search buses for hardware timer |
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| 146 | */ |
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| 147 | Clock_driver_support_find_timer(); |
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| 148 | |
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| 149 | /* |
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| 150 | * Install vector |
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| 151 | */ |
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| 152 | Clock_driver_support_install_isr( clock_isr, Old_ticker ); |
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| 153 | |
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| 154 | #if defined(Clock_driver_nanoseconds_since_last_tick) |
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| 155 | rtems_clock_set_nanoseconds_extension( |
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| 156 | Clock_driver_nanoseconds_since_last_tick |
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| 157 | ); |
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| 158 | #endif |
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| 159 | |
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| 160 | /* |
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| 161 | * Now initialize the hardware that is the source of the tick ISR. |
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| 162 | */ |
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| 163 | Clock_driver_support_initialize_hardware(); |
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| 164 | |
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| 165 | atexit( Clock_exit ); |
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| 166 | } |
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| 167 | |
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| 168 | /* |
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| 169 | * Clock_exit |
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| 170 | * |
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| 171 | * This routine allows the clock driver to exit by masking the interrupt and |
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| 172 | * disabling the clock's counter. |
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| 173 | * |
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| 174 | * Input parameters: NONE |
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| 175 | * |
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| 176 | * Output parameters: NONE |
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| 177 | * |
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| 178 | * Return values: NONE |
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| 179 | * |
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| 180 | */ |
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| 181 | |
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| 182 | void Clock_exit( void ) |
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| 183 | { |
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| 184 | Clock_driver_support_shutdown_hardware(); |
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| 185 | |
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| 186 | /* do not restore old vector */ |
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| 187 | } |
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| 188 | |
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| 189 | /* |
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| 190 | * Clock_initialize |
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| 191 | * |
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| 192 | * This routine initializes the clock driver. |
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| 193 | * |
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| 194 | * Input parameters: |
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| 195 | * major - clock device major number |
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| 196 | * minor - clock device minor number |
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| 197 | * parg - pointer to optional device driver arguments |
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| 198 | * |
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| 199 | * Output parameters: NONE |
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| 200 | * |
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| 201 | * Return values: |
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| 202 | * rtems_device_driver status code |
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| 203 | */ |
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| 204 | |
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| 205 | rtems_device_driver Clock_initialize( |
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| 206 | rtems_device_major_number major, |
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| 207 | rtems_device_minor_number minor, |
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| 208 | void *pargp |
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| 209 | ) |
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| 210 | { |
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| 211 | Install_clock( Clock_isr ); |
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| 212 | |
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| 213 | /* |
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| 214 | * make major/minor avail to others such as shared memory driver |
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| 215 | */ |
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| 216 | |
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| 217 | rtems_clock_major = major; |
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| 218 | rtems_clock_minor = minor; |
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| 219 | |
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| 220 | /* |
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| 221 | * If we are counting ISRs per tick, then initialize the counter. |
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| 222 | */ |
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| 223 | |
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| 224 | #ifdef CLOCK_DRIVER_ISRS_PER_TICK |
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| 225 | Clock_driver_isrs = CLOCK_DRIVER_ISRS_PER_TICK; |
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| 226 | #endif |
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| 227 | |
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| 228 | return RTEMS_SUCCESSFUL; |
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| 229 | } |
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