From 89611889fe6e255dec90a5157a4f25c0f65057b4 Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Tue, 14 Apr 1998 19:49:13 +0000 Subject: new files --- c/src/lib/libbsp/powerpc/psim/clock/clock.c | 240 ++++++++++++++++++++++++++++ 1 file changed, 240 insertions(+) create mode 100644 c/src/lib/libbsp/powerpc/psim/clock/clock.c (limited to 'c/src/lib/libbsp/powerpc/psim/clock/clock.c') diff --git a/c/src/lib/libbsp/powerpc/psim/clock/clock.c b/c/src/lib/libbsp/powerpc/psim/clock/clock.c new file mode 100644 index 0000000000..cc57e3ed7d --- /dev/null +++ b/c/src/lib/libbsp/powerpc/psim/clock/clock.c @@ -0,0 +1,240 @@ +/* + * Clock Tick Device Driver + * + * This routine utilizes the Decrementer Register common to the PPC family. + * + * The tick frequency is directly programmed to the configured number of + * microseconds per tick. + * + * COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994, 1997. + * On-Line Applications Research Corporation (OAR). + * All rights assigned to U.S. Government, 1994. + * + * This material may be reproduced by or for the U.S. Government pursuant + * to the copyright license under the clause at DFARS 252.227-7013. This + * notice must appear in all copies of this file and its derivatives. + * + * $Id$ + */ + +#include + +#include +#include + +/* + * The Real Time Clock Counter Timer uses this trap type. + */ + +#define CLOCK_VECTOR PPC_IRQ_DECREMENTER + +/* + * 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 PSIM_FAST_IDLE is defined to + * cut down how long we spend in the idle task while executing on + * the simulator. + */ + +extern rtems_unsigned32 CPU_PPC_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 + * + */ + +#define PPC_Set_decrementer( _clicks ) \ + do { \ + asm volatile( "mtdec %0" : "=r" ((_clicks)) : "r" ((_clicks)) ); \ + } while (0) + +rtems_isr Clock_isr( + rtems_vector_number vector +) +{ + /* + * Whether or not we we are in "fast idle" mode, the value for clicks + * per tick must be programmed. If we are using "fast idle" mode for + * a simulator, then the clicks per tick value is lowered to decrease + * the amount of time spent executing the idle task while using the + * an instruction simulator like psim. + */ + + + PPC_Set_decrementer( CPU_PPC_CLICKS_PER_TICK ); + + /* + * 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; + + if ( BSP_Configuration.ticks_per_timeslice ) { + Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 ); + + PPC_Set_decrementer( CPU_PPC_CLICKS_PER_TICK ); + + 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 ) +{ + if ( BSP_Configuration.ticks_per_timeslice ) { + + /* nothing to do */; + + /* 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; +} -- cgit v1.2.3