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authorJoel Sherrill <joel.sherrill@OARcorp.com>1998-04-14 19:49:13 +0000
committerJoel Sherrill <joel.sherrill@OARcorp.com>1998-04-14 19:49:13 +0000
commit89611889fe6e255dec90a5157a4f25c0f65057b4 (patch)
tree2facca64edc8503b3149c8157a43fb6674e4523f /c/src/lib/libbsp/powerpc/psim/clock/clock.c
parentChanged arc to archive. (diff)
downloadrtems-89611889fe6e255dec90a5157a4f25c0f65057b4.tar.bz2
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Diffstat (limited to '')
-rw-r--r--c/src/lib/libbsp/powerpc/psim/clock/clock.c240
1 files changed, 240 insertions, 0 deletions
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
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+++ 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 <stdlib.h>
+
+#include <bsp.h>
+#include <rtems/libio.h>
+
+/*
+ * 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;
+}