[c932d85] | 1 | /* |
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| 2 | * Clock Tick Device Driver |
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| 3 | * |
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| 4 | * This routine utilizes the Decrementer Register common to the PPC family. |
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| 5 | * |
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| 6 | * The tick frequency is directly programmed to the configured number of |
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| 7 | * microseconds per tick. |
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| 8 | * |
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| 9 | * COPYRIGHT (c) 1989-1997. |
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| 10 | * On-Line Applications Research Corporation (OAR). |
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| 11 | * |
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| 12 | * The license and distribution terms for this file may in |
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| 13 | * the file LICENSE in this distribution or at |
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| 14 | * http://www.OARcorp.com/rtems/license.html. |
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| 15 | * |
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| 16 | * $Id$ |
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| 17 | */ |
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| 18 | |
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| 19 | #include <stdlib.h> |
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| 20 | |
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| 21 | #include <bsp.h> |
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| 22 | #include <rtems/libio.h> |
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| 23 | |
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[2785eab2] | 24 | extern rtems_cpu_table Cpu_table; |
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| 25 | |
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[c932d85] | 26 | /* |
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| 27 | * The Real Time Clock Counter Timer uses this trap type. |
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| 28 | */ |
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| 29 | |
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| 30 | #define CLOCK_VECTOR PPC_IRQ_DECREMENTER |
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| 31 | |
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| 32 | /* |
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| 33 | * Clock ticks since initialization |
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| 34 | */ |
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| 35 | |
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| 36 | volatile rtems_unsigned32 Clock_driver_ticks; |
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| 37 | |
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| 38 | /* |
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| 39 | * This is the value programmed into the count down timer. |
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| 40 | */ |
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| 41 | |
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| 42 | rtems_unsigned32 Clock_Decrementer_value; |
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| 43 | |
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| 44 | /* |
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| 45 | * This is the value of the old isr routine. |
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| 46 | */ |
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| 47 | rtems_isr_entry Old_ticker; |
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| 48 | |
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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 | * These are set by clock driver during its init |
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| 54 | */ |
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| 55 | |
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| 56 | rtems_device_major_number rtems_clock_major = ~0; |
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| 57 | rtems_device_minor_number rtems_clock_minor; |
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| 58 | |
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[dc104a4] | 59 | /*PAGE |
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[c932d85] | 60 | * |
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| 61 | * Clock_isr |
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| 62 | * |
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| 63 | * This is the clock tick interrupt handler. |
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| 64 | * |
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| 65 | * Input parameters: |
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| 66 | * vector - vector number |
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| 67 | * |
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| 68 | * Output parameters: NONE |
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| 69 | * |
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| 70 | * Return values: NONE |
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| 71 | * |
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| 72 | */ |
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| 73 | |
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| 74 | rtems_isr Clock_isr( |
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| 75 | rtems_vector_number vector, |
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| 76 | CPU_Interrupt_frame *frame |
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| 77 | ) |
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| 78 | { |
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| 79 | /* |
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| 80 | * Set the decrementer. |
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| 81 | */ |
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| 82 | |
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| 83 | PPC_Set_decrementer( Clock_Decrementer_value ); |
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| 84 | |
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| 85 | /* |
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| 86 | * The driver has seen another tick. |
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| 87 | */ |
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| 88 | |
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| 89 | Clock_driver_ticks += 1; |
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| 90 | |
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| 91 | /* |
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| 92 | * Real Time Clock counter/timer is set to automatically reload. |
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| 93 | */ |
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| 94 | |
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| 95 | rtems_clock_tick(); |
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| 96 | } |
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| 97 | |
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[dc104a4] | 98 | /*PAGE |
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[c932d85] | 99 | * |
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| 100 | * Install_clock |
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| 101 | * |
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| 102 | * This routine actually performs the hardware initialization for the clock. |
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| 103 | * |
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| 104 | * Input parameters: |
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| 105 | * clock_isr - clock interrupt service routine entry point |
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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 | extern int CLOCK_SPEED; |
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| 114 | |
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| 115 | void Install_clock( |
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| 116 | rtems_isr_entry clock_isr |
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| 117 | ) |
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| 118 | { |
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| 119 | Clock_driver_ticks = 0; |
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| 120 | |
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[0dd1d44] | 121 | Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 ); |
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[c932d85] | 122 | |
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[0dd1d44] | 123 | PPC_Set_decrementer( Clock_Decrementer_value ); |
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[c932d85] | 124 | |
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[0dd1d44] | 125 | atexit( Clock_exit ); |
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[c932d85] | 126 | } |
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| 127 | |
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[dc104a4] | 128 | /*PAGE |
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[c932d85] | 129 | * |
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| 130 | * Clock_exit |
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| 131 | * |
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| 132 | * This routine allows the clock driver to exit by masking the interrupt and |
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| 133 | * disabling the clock's counter. |
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| 134 | * |
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| 135 | * Input parameters: NONE |
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| 136 | * |
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| 137 | * Output parameters: NONE |
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| 138 | * |
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| 139 | * Return values: NONE |
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| 140 | * |
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| 141 | */ |
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| 142 | |
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| 143 | void Clock_exit( void ) |
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| 144 | { |
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[0dd1d44] | 145 | /* nothing to do */; |
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[c932d85] | 146 | |
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[0dd1d44] | 147 | /* do not restore old vector */ |
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[c932d85] | 148 | } |
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| 149 | |
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[dc104a4] | 150 | /*PAGE |
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[c932d85] | 151 | * |
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| 152 | * Clock_initialize |
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| 153 | * |
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| 154 | * This routine initializes the clock driver. |
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| 155 | * |
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| 156 | * Input 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 | * parg - pointer to optional device driver arguments |
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| 160 | * |
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| 161 | * Output parameters: NONE |
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| 162 | * |
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| 163 | * Return values: |
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| 164 | * rtems_device_driver status code |
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| 165 | */ |
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| 166 | |
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| 167 | rtems_device_driver Clock_initialize( |
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| 168 | rtems_device_major_number major, |
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| 169 | rtems_device_minor_number minor, |
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| 170 | void *pargp |
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| 171 | ) |
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| 172 | { |
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[2785eab2] | 173 | Clock_Decrementer_value = Cpu_table.clicks_per_usec * |
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| 174 | BSP_Configuration.microseconds_per_tick; |
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[c932d85] | 175 | |
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| 176 | Install_clock( Clock_isr ); |
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| 177 | |
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| 178 | /* |
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| 179 | * make major/minor avail to others such as shared memory driver |
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| 180 | */ |
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| 181 | |
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| 182 | rtems_clock_major = major; |
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| 183 | rtems_clock_minor = minor; |
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| 184 | |
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| 185 | return RTEMS_SUCCESSFUL; |
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| 186 | } |
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| 187 | |
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| 188 | /* PAGE |
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| 189 | * |
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| 190 | * Clock_control |
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| 191 | * |
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| 192 | * This routine is the clock device driver control entry point. |
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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_control( |
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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 | rtems_unsigned32 isrlevel; |
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| 212 | rtems_libio_ioctl_args_t *args = pargp; |
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| 213 | |
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| 214 | if (args == 0) |
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| 215 | goto done; |
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| 216 | |
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| 217 | /* |
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| 218 | * This is hokey, but until we get a defined interface |
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| 219 | * to do this, it will just be this simple... |
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| 220 | */ |
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| 221 | |
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| 222 | if (args->command == rtems_build_name('I', 'S', 'R', ' ')) |
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| 223 | { |
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| 224 | Clock_isr( CLOCK_VECTOR, pargp ); |
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| 225 | } |
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| 226 | else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) |
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| 227 | { |
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| 228 | rtems_interrupt_disable( isrlevel ); |
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| 229 | (void) set_vector( args->buffer, CLOCK_VECTOR, 1 ); |
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| 230 | rtems_interrupt_enable( isrlevel ); |
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| 231 | } |
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| 232 | |
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| 233 | done: |
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| 234 | return RTEMS_SUCCESSFUL; |
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| 235 | } |
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| 236 | |
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| 237 | |
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| 238 | |
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| 239 | |
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| 240 | |
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