summaryrefslogtreecommitdiffstats
path: root/c/src/lib/libbsp/i386/pc386/clock/ckinit.c
diff options
context:
space:
mode:
Diffstat (limited to 'c/src/lib/libbsp/i386/pc386/clock/ckinit.c')
-rw-r--r--c/src/lib/libbsp/i386/pc386/clock/ckinit.c285
1 files changed, 285 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/i386/pc386/clock/ckinit.c b/c/src/lib/libbsp/i386/pc386/clock/ckinit.c
new file mode 100644
index 0000000000..e02510c70e
--- /dev/null
+++ b/c/src/lib/libbsp/i386/pc386/clock/ckinit.c
@@ -0,0 +1,285 @@
+/*-------------------------------------------------------------------------+
+| ckinit.c v1.1 - PC386 BSP - 1997/08/07
++--------------------------------------------------------------------------+
+| This file contains the PC386 clock package.
++--------------------------------------------------------------------------+
+| (C) Copyright 1997 -
+| - NavIST Group - Real-Time Distributed Systems and Industrial Automation
+|
+| http://pandora.ist.utl.pt
+|
+| Instituto Superior Tecnico * Lisboa * PORTUGAL
++--------------------------------------------------------------------------+
+| Disclaimer:
+|
+| This file is provided "AS IS" without warranty of any kind, either
+| expressed or implied.
++--------------------------------------------------------------------------+
+| This code is based on:
+| ckinit.c,v 1.4 1995/12/19 20:07:13 joel Exp - go32 BSP
+| With the following copyright notice:
+| **************************************************************************
+| * COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994. *
+| * 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. *
+| **************************************************************************
++--------------------------------------------------------------------------*/
+
+
+#include <stdlib.h>
+
+#include <bsp.h>
+#include <irq.h>
+#include <rtems/libio.h>
+
+/*-------------------------------------------------------------------------+
+| Constants
++--------------------------------------------------------------------------*/
+#define CLOCK_IRQ 0x00 /* Clock IRQ. */
+
+/*-------------------------------------------------------------------------+
+| Macros
++--------------------------------------------------------------------------*/
+#if 0
+/* This was dropped in the last revision. Its a nice thing to know. */
+#define TICKS_PER_SECOND() \
+ (1000000 / (Clock_isrs_per_tick * microseconds_per_isr))
+#endif /* 0 */
+
+/*-------------------------------------------------------------------------+
+| Global Variables
++--------------------------------------------------------------------------*/
+
+volatile rtems_unsigned32 Clock_driver_ticks; /* Tick (interrupt) counter. */
+ rtems_unsigned32 Clock_isrs_per_tick; /* ISRs per tick. */
+ rtems_unsigned32 Clock_isrs; /* ISRs until next tick. */
+
+/* The following variables are set by the clock driver during its init */
+
+rtems_device_major_number rtems_clock_major = ~0;
+rtems_device_minor_number rtems_clock_minor;
+
+/*-------------------------------------------------------------------------+
+| Function: clockIsr
+| Description: Interrupt Service Routine for clock (08h) interruption.
+| Global Variables: Clock_driver_ticks, Clock_isrs.
+| Arguments: vector - standard RTEMS argument - see documentation.
+| Returns: standard return value - see documentation.
++--------------------------------------------------------------------------*/
+static rtems_isr
+clockIsr(rtems_vector_number vector)
+{
+ /*-------------------------------------------------------------------------+
+ | PLEASE NOTE: The following is directly transcribed from the go32 BSP for
+ | those who wish to use it with PENTIUM based machine. It needs
+ | to be correctly integrated with the rest of the code!!!
+ +--------------------------------------------------------------------------*/
+
+#if 0 && defined(pentium) /* more accurate clock for PENTIUMs (not supported) */
+ {
+ extern long long Last_RDTSC;
+ __asm __volatile(".byte 0x0F, 0x31" : "=A" (Last_RDTSC));
+ }
+#endif /* 0 && pentium */
+
+ Clock_driver_ticks++;
+
+ if ( Clock_isrs == 1 )
+ {
+ rtems_clock_tick();
+ Clock_isrs = Clock_isrs_per_tick;
+ }
+ else
+ Clock_isrs--;
+
+ PC386_ackIrq(vector - PC386_IRQ_VECTOR_BASE);
+} /* clockIsr */
+
+
+/*-------------------------------------------------------------------------+
+| Function: Clock_exit
+| Description: Clock cleanup routine at RTEMS exit. NOTE: This routine is
+| not really necessary, since there will be a reset at exit.
+| Global Variables: None.
+| Arguments: None.
+| Returns: Nothing.
++--------------------------------------------------------------------------*/
+void Clock_exit(void)
+{
+ if (BSP_Configuration.ticks_per_timeslice)
+ {
+ /* reset timer mode to standard (BIOS) value */
+ outport_byte(TIMER_MODE, TIMER_SEL0 | TIMER_16BIT | TIMER_RATEGEN);
+ outport_byte(TIMER_CNTR0, 0);
+ outport_byte(TIMER_CNTR0, 0);
+ }
+} /* Clock_exit */
+
+
+/*-------------------------------------------------------------------------+
+| Function: Install_clock
+| Description: Initialize and install clock interrupt handler.
+| Global Variables: None.
+| Arguments: None.
+| Returns: Nothing.
++--------------------------------------------------------------------------*/
+void
+Install_clock(rtems_isr_entry isr)
+{
+ rtems_unsigned32 microseconds_per_isr;
+
+ rtems_status_code status;
+
+#if 0
+ /* Initialize clock from on-board real time clock. This breaks the */
+ /* test code which assumes which assumes the application will do it. */
+ {
+ rtems_time_of_day now;
+
+ /* External Prototypes */
+ extern void init_rtc(void); /* defined in 'rtc.c' */
+ extern long rtc_read(rtems_time_of_day *); /* defined in 'rtc.c' */
+
+ init_rtc();
+ if (rtc_read(&now) >= 0)
+ clock_set(&now);
+ }
+#endif /* 0 */
+
+ /* Start by assuming hardware counter is large enough, then scale it until
+ it actually fits. */
+
+ Clock_driver_ticks = 0;
+ Clock_isrs_per_tick = 1;
+
+ if (BSP_Configuration.microseconds_per_tick == 0)
+ microseconds_per_isr = 10000; /* default 10 ms */
+ else
+ microseconds_per_isr = BSP_Configuration.microseconds_per_tick;
+ while (US_TO_TICK(microseconds_per_isr) > 65535)
+ {
+ Clock_isrs_per_tick *= 10;
+ microseconds_per_isr /= 10;
+ }
+
+ Clock_isrs = Clock_isrs_per_tick; /* Initialize Clock_isrs */
+
+ if (BSP_Configuration.ticks_per_timeslice)
+ {
+ /* 105/88 approximates TIMER_TICK * 1e-6 */
+ rtems_unsigned32 count = US_TO_TICK(microseconds_per_isr);
+
+ status = PC386_installRtemsIrqHandler(CLOCK_IRQ, isr);
+
+ if (status != RTEMS_SUCCESSFUL)
+ {
+ printk("Error installing clock interrupt handler!\n");
+ rtems_fatal_error_occurred(status);
+ }
+
+ outport_byte(TIMER_MODE, TIMER_SEL0|TIMER_16BIT|TIMER_RATEGEN);
+ outport_byte(TIMER_CNTR0, count >> 0 & 0xff);
+ outport_byte(TIMER_CNTR0, count >> 8 & 0xff);
+ }
+
+ atexit(Clock_exit);
+} /* Install_clock */
+
+
+/*-------------------------------------------------------------------------+
+| Clock device driver INITIALIZE entry point.
++--------------------------------------------------------------------------+
+| Initilizes the clock driver.
++--------------------------------------------------------------------------*/
+rtems_device_driver
+Clock_initialize(rtems_device_major_number major,
+ rtems_device_minor_number minor,
+ void *pargp)
+{
+ Install_clock(clockIsr); /* Install the interrupt handler */
+
+ /* make major/minor avail to others such as shared memory driver */
+
+ rtems_clock_major = major;
+ rtems_clock_minor = minor;
+
+ return RTEMS_SUCCESSFUL;
+} /* Clock_initialize */
+
+
+/*-------------------------------------------------------------------------+
+| Console device driver CONTROL entry point
++--------------------------------------------------------------------------*/
+rtems_device_driver
+Clock_control(rtems_device_major_number major,
+ rtems_device_minor_number minor,
+ void *pargp)
+{
+ if (pargp != NULL)
+ {
+ rtems_libio_ioctl_args_t *args = pargp;
+
+ /*-------------------------------------------------------------------------+
+ | 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', ' '))
+ clockIsr(PC386_IRQ_VECTOR_BASE + CLOCK_IRQ);
+ else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
+ {
+ rtems_status_code status;
+
+ status = PC386_installRtemsIrqHandler(CLOCK_IRQ, clockIsr);
+
+ if (status != RTEMS_SUCCESSFUL)
+ {
+ printk("Error installing clock interrupt handler!\n");
+ rtems_fatal_error_occurred(status);
+ }
+ }
+ }
+
+ return RTEMS_SUCCESSFUL;
+} /* Clock_control */
+
+
+/*-------------------------------------------------------------------------+
+| PLEASE NOTE: The following is directly transcribed from the go32 BSP for
+| those who wish to use it with PENTIUM based machine. It needs
+| to be correctly integrated with the rest of the code!!!
++--------------------------------------------------------------------------*/
+
+
+#if 0 && defined(pentium)
+
+/* This can be used to get extremely accurate timing on a pentium. */
+/* It isn't supported. [bryce] */
+
+#define HZ 90.0
+
+volatile long long Last_RDTSC;
+
+#define RDTSC()\
+ ({ long long _now; __asm __volatile (".byte 0x0F,0x31":"=A"(_now)); _now; })
+
+long long Kernel_Time_ns( void )
+{
+ extern rtems_unsigned32 _TOD_Ticks_per_second;
+
+ unsigned isrs_per_second = Clock_isrs_per_tick * _TOD_Ticks_per_second;
+ long long now;
+ int flags;
+
+ disable_intr(flags);
+ now = 1e9 * Clock_driver_ticks / isrs_per_second +
+ (RDTSC() - Last_RDTSC) * (1000.0/HZ);
+ enable_intr(flags);
+ return now;
+} /* Kernel_Time_ns */
+
+#endif /* 0 && pentium */
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-02 04:51:58 +0000