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2001-01-12 Eric Norum <eric.norum@usask.ca>

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* README, clock/Makefile.am, clock/ckinit.c, clock/clock.c:
	Clock driver updated to use shell driver mechanism.
	* clock/ckinit.c: Removed.
	* clock/clock.c: New file.
This commit is contained in:
Joel Sherrill
2001-01-12 15:00:54 +00:00
parent 3f777d0edf
commit c2a4084fe4
5 changed files with 112 additions and 195 deletions
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7
c/src/lib/libbsp/m68k/gen68360/ChangeLog
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@@ -1,3 +1,10 @@
2001-01-12 Eric Norum <eric.norum@usask.ca>
* README, clock/Makefile.am, clock/ckinit.c, clock/clock.c:
Clock driver updated to use shell driver mechanism.
* clock/ckinit.c: Removed.
* clock/clock.c: New file.
2000-12-19 Joel Sherrill <joel@OARcorp.com>
* Makefile.am: Removed unneeded blank line.

2
c/src/lib/libbsp/m68k/gen68360/README
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@@ -302,7 +302,7 @@ The board support package has been tested with:
Interrupt Notes
===============
ckinit.c:
clock.c:
Occasional network lockups have been noted when the PIT has a higher
interrupt request level than the CPM. The SCC1 bit in the CISR is set
even though the SCC1 interrupt handler is not active. This blocks

4
c/src/lib/libbsp/m68k/gen68360/clock/Makefile.am
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@@ -6,7 +6,7 @@ AUTOMAKE_OPTIONS = foreign 1.4
PGM = $(ARCH)/clock.rel
C_FILES = ckinit.c
C_FILES = clock.c
C_O_FILES = $(C_FILES:%.c=$(ARCH)/%.o)
OBJS = $(C_O_FILES)
@@ -28,6 +28,6 @@ all-local: $(ARCH) $(OBJS) $(PGM)
.PRECIOUS: $(PGM)
EXTRA_DIST = ckinit.c
EXTRA_DIST = clock.c
include $(top_srcdir)/../../../../../../automake/local.am

192
c/src/lib/libbsp/m68k/gen68360/clock/ckinit.c
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@@ -1,192 +0,0 @@
/*
* This routine initializes the MC68360 Periodic Interval Timer
*
* The PIT has rather poor resolution, but it is easy to set up
* and requires no housekeeping once it is going.
*
* Based on the `gen68302' board support package, and covered by the
* original distribution terms.
*
* W. Eric Norum
* Saskatchewan Accelerator Laboratory
* University of Saskatchewan
* Saskatoon, Saskatchewan, CANADA
* eric@skatter.usask.ca
*
* $Id$
*/
/*
* Input parameters: NONE
*
* Output parameters: NONE
*
* 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.
*/
#include <stdlib.h> /* for atexit() */
#include <bsp.h>
#include <rtems/libio.h>
#include "m68360.h"
#define CLOCK_VECTOR 120
#define CLOCK_IRQ_LEVEL 4
/*
* Clock_driver_ticks is a monotonically increasing counter of the
* number of clock ticks since the driver was initialized.
*/
volatile rtems_unsigned32 Clock_driver_ticks;
/*
* These are set by clock driver during its init
*/
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_minor_number rtems_clock_minor;
char M360DefaultWatchdogFeeder = 1;
/*
* RTEMS and hardware have different notions of clock rate.
*/
static unsigned long rtems_nsec_per_tick;
static unsigned long pit_nsec_per_tick;
/*
* Periodic interval timer interrupt handler
*/
rtems_isr
Clock_isr (rtems_vector_number vector)
{
static unsigned long nsec;
/*
* See if it's really time for a `tick'
*/
nsec += pit_nsec_per_tick;
if (nsec >= rtems_nsec_per_tick) {
nsec -= rtems_nsec_per_tick;
/*
* Perform a dummy read of DPRAM.
* This works around a bug in Rev. B of the 68360
*/
m360.dpram0[0];
/*
* Feed the watchdog
* Application code can override this by
* setting M360DefaultWatchdogFeeder to zero.
*/
if (M360DefaultWatchdogFeeder) {
m360.swsr = 0x55;
m360.swsr = 0xAA;
}
/*
* Announce the clock tick
*/
Clock_driver_ticks++;
rtems_clock_tick();
}
}
void
Clock_exit (void)
{
/*
* Turn off periodic interval timer
*/
m360.pitr &= ~0xFF;
}
static void
Install_clock (rtems_isr_entry clock_isr)
{
int divisor;
extern int m360_clock_rate; /* This should be somewhere in a config file */
unsigned long nsec_per_chip_tick = 1000000000 / m360_clock_rate;
unsigned long nsec_per_pit_tick = 512 * nsec_per_chip_tick;
Clock_driver_ticks = 0;
/*
* Choose periodic interval timer register value
* The rate at which the periodic interval timer
* can generate interrupts is almost certainly not
* the same as desired by the BSP configuration.
* Handle the difference by choosing the largest PIT
* interval which is less than or equal to the RTEMS
* interval and skipping some hardware interrupts.
* To reduce the jitter in the calls to RTEMS the
* hardware interrupt interval is never less than
* the maximum non-prescaled value from the PIT.
*
* For a 25 MHz external clock the basic clock rate is
* 40 nsec * 128 * 4 = 20.48 usec/tick
*/
rtems_nsec_per_tick = BSP_Configuration.microseconds_per_tick * 1000;
divisor = rtems_nsec_per_tick / nsec_per_pit_tick;
if (divisor >= 256) {
divisor = 255;
} else if (divisor == 0) {
divisor = 1;
}
pit_nsec_per_tick = nsec_per_pit_tick * divisor;
m360.pitr &= ~0x1FF;
m360.picr = (CLOCK_IRQ_LEVEL << 8) | CLOCK_VECTOR;
set_vector (clock_isr, CLOCK_VECTOR, 1);
m360.pitr |= divisor;
atexit (Clock_exit);
}
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;
}
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) {
/*
* 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 );
}
}
return RTEMS_SUCCESSFUL;
}

102
c/src/lib/libbsp/m68k/gen68360/clock/clock.c Normal file
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@@ -0,0 +1,102 @@
/*
* This routine initializes the MC68360 Periodic Interval Timer
*
* The PIT has rather poor resolution, but it is easy to set up
* and requires no housekeeping once it is going.
*
* W. Eric Norum
* Saskatchewan Accelerator Laboratory
* University of Saskatchewan
* Saskatoon, Saskatchewan, CANADA
* eric@skatter.usask.ca
*
* $Id$
*/
#include <rtems.h>
#include <bsp.h>
#include "m68360.h"
#define CLOCK_VECTOR 120
#define CLOCK_IRQ_LEVEL 4
char M360DefaultWatchdogFeeder = 1;
/*
* RTEMS and hardware have different notions of clock rate.
*/
static unsigned long rtems_nsec_per_tick;
static unsigned long pit_nsec_per_tick;
static unsigned long nsec;
/*
* Periodic interval timer interrupt handler
* See if it's really time for a `tick'
* Perform a dummy read of DPRAM (work around bug in Rev. B of the 68360).
* Feed the watchdog
* Application code can override this by
* setting M360DefaultWatchdogFeeder to zero.
*/
#define Clock_driver_support_at_tick() \
do { \
nsec += pit_nsec_per_tick; \
if (nsec >= rtems_nsec_per_tick) \
return; \
nsec -= rtems_nsec_per_tick; \
m360.dpram0[0]; \
if (M360DefaultWatchdogFeeder) { \
m360.swsr = 0x55; \
m360.swsr = 0xAA; \
} \
} while (0) \
/*
* Attach clock interrupt handler
*/
#define Clock_driver_support_install_isr( _new, _old ) \
do { \
_old = (rtems_isr_entry)set_vector(_new, CLOCK_VECTOR, 1); \
} while(0)
/*
* Turn off the clock
*/
#define Clock_driver_support_shutdown_hardware() \
do { \
m360.pitr &= ~0xFF; \
} while(0)
/*
* Set up the clock hardware
* The rate at which the periodic interval timer
* can generate interrupts is almost certainly not
* the same as desired by the BSP configuration.
* Handle the difference by choosing the largest PIT
* interval which is less than or equal to the RTEMS
* interval and skipping some hardware interrupts.
* To reduce the jitter in the calls to RTEMS the
* hardware interrupt interval is never greater than
* the maximum non-prescaled value from the PIT.
*
* For a 25 MHz external clock the basic clock rate is
* 40 nsec * 128 * 4 = 20.48 usec/tick
*/
#define Clock_driver_support_initialize_hardware() \
do { \
unsigned int divisor; \
extern int m360_clock_rate; \
unsigned long nsec_per_chip_tick = 1000000000 / m360_clock_rate; \
unsigned long nsec_per_pit_tick = 512 * nsec_per_chip_tick; \
rtems_nsec_per_tick = BSP_Configuration.microseconds_per_tick * 1000; \
divisor = rtems_nsec_per_tick / nsec_per_pit_tick; \
if (divisor > 255) \
divisor = 255; \
else if (divisor == 0) \
divisor = 1; \
pit_nsec_per_tick = nsec_per_pit_tick * divisor; \
m360.pitr &= ~0x1FF; \
m360.picr = (CLOCK_IRQ_LEVEL << 8) | CLOCK_VECTOR; \
m360.pitr |= divisor; \
} while (0)
#include "../../../shared/clockdrv_shell.c"