/* * Clock Tick Device Driver * * This routine initializes the Real Time Clock Counter Timer which is * part of the MEC on the ERC32 CPU. * * The tick frequency is directly programmed to the configured number of * microseconds per tick. * * COPYRIGHT (c) 1989-1999. * On-Line Applications Research Corporation (OAR). * * The license and distribution terms for this file may be * found in the file LICENSE in this distribution or at * http://www.OARcorp.com/rtems/license.html. * * Ported to ERC32 implementation of the SPARC by On-Line Applications * Research Corporation (OAR) under contract to the European Space * Agency (ESA). * * ERC32 modifications of respective RTEMS file: COPYRIGHT (c) 1995. * European Space Agency. * * $Id$ */ #include #include #include /* * The Real Time Clock Counter Timer uses this trap type. */ #define CLOCK_VECTOR ERC32_TRAP_TYPE( ERC32_INTERRUPT_REAL_TIME_CLOCK ) /* * Clock ticks since initialization */ volatile rtems_unsigned32 Clock_driver_ticks; /* * This is the value programmed into the count down timer. It * is artificially lowered when SIMSPARC_FAST_IDLE is defined to * cut down how long we spend in the idle task while executing on * the simulator. */ extern rtems_unsigned32 CPU_SPARC_CLICKS_PER_TICK; rtems_isr_entry Old_ticker; void Clock_exit( void ); /* * These are set by clock driver during its init */ rtems_device_major_number rtems_clock_major = ~0; rtems_device_minor_number rtems_clock_minor; /* * Clock_isr * * This is the clock tick interrupt handler. * * Input parameters: * vector - vector number * * Output parameters: NONE * * Return values: NONE * */ rtems_isr Clock_isr( rtems_vector_number vector ) { /* * If we are in "fast idle" mode, then the value for clicks per tick * is lowered to decrease the amount of time spent executing the idle * task while using the SPARC Instruction Simulator. */ #if SIMSPARC_FAST_IDLE ERC32_MEC.Real_Time_Clock_Counter = CPU_SPARC_CLICKS_PER_TICK; ERC32_MEC_Set_Real_Time_Clock_Timer_Control( ERC32_MEC_TIMER_COUNTER_ENABLE_COUNTING | ERC32_MEC_TIMER_COUNTER_LOAD_COUNTER ); #endif /* * The driver has seen another tick. */ Clock_driver_ticks += 1; /* * Real Time Clock counter/timer is set to automatically reload. */ rtems_clock_tick(); } /* * Install_clock * * This routine actually performs the hardware initialization for the clock. * * Input parameters: * clock_isr - clock interrupt service routine entry point * * Output parameters: NONE * * Return values: NONE * */ extern int CLOCK_SPEED; void Install_clock( rtems_isr_entry clock_isr ) { Clock_driver_ticks = 0; Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 ); /* approximately 1 us per countdown */ ERC32_MEC.Real_Time_Clock_Scalar = CLOCK_SPEED - 1; ERC32_MEC.Real_Time_Clock_Counter = CPU_SPARC_CLICKS_PER_TICK; ERC32_MEC_Set_Real_Time_Clock_Timer_Control( ERC32_MEC_TIMER_COUNTER_ENABLE_COUNTING | ERC32_MEC_TIMER_COUNTER_LOAD_SCALER | ERC32_MEC_TIMER_COUNTER_LOAD_COUNTER ); ERC32_MEC_Set_Real_Time_Clock_Timer_Control( ERC32_MEC_TIMER_COUNTER_ENABLE_COUNTING | ERC32_MEC_TIMER_COUNTER_RELOAD_AT_ZERO ); atexit( Clock_exit ); } /* * Clock_exit * * This routine allows the clock driver to exit by masking the interrupt and * disabling the clock's counter. * * Input parameters: NONE * * Output parameters: NONE * * Return values: NONE * */ void Clock_exit( void ) { ERC32_Mask_interrupt( ERC32_INTERRUPT_REAL_TIME_CLOCK ); ERC32_MEC_Set_Real_Time_Clock_Timer_Control( ERC32_MEC_TIMER_COUNTER_DISABLE_COUNTING ); /* do not restore old vector */ } /* * Clock_initialize * * This routine initializes the clock driver. * * Input parameters: * major - clock device major number * minor - clock device minor number * parg - pointer to optional device driver arguments * * Output parameters: NONE * * Return values: * rtems_device_driver status code */ rtems_device_driver Clock_initialize( rtems_device_major_number major, rtems_device_minor_number minor, void *pargp ) { Install_clock( Clock_isr ); /* * make major/minor avail to others such as shared memory driver */ rtems_clock_major = major; rtems_clock_minor = minor; return RTEMS_SUCCESSFUL; } /* * Clock_control * * This routine is the clock device driver control entry point. * * Input parameters: * major - clock device major number * minor - clock device minor number * parg - pointer to optional device driver arguments * * Output parameters: NONE * * Return values: * rtems_device_driver status code */ rtems_device_driver Clock_control( rtems_device_major_number major, rtems_device_minor_number minor, void *pargp ) { rtems_unsigned32 isrlevel; rtems_libio_ioctl_args_t *args = pargp; if (args == 0) goto done; /* * This is hokey, but until we get a defined interface * to do this, it will just be this simple... */ if (args->command == rtems_build_name('I', 'S', 'R', ' ')) { Clock_isr(CLOCK_VECTOR); } else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) { rtems_interrupt_disable( isrlevel ); (void) set_vector( args->buffer, CLOCK_VECTOR, 1 ); rtems_interrupt_enable( isrlevel ); } done: return RTEMS_SUCCESSFUL; }