Subversion Repositories openrisc

/*  ckinit.c

 *

 *  This file provides a template for the clock device driver initialization.

 *

 *  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.

 *

 *  $Id: ckinit.c,v 1.1 2001-09-27 12:00:27 chris Exp $

 */

#include <stdlib.h>

#include <rtems.h>

#include <rtems/libio.h>

#include <bsp.h>

static void (*old_handler)(unsigned int,unsigned int,unsigned int,unsigned int);

void Clock_exit( void );

void Clock_isr( rtems_vector_number vector,unsigned int pc,

                unsigned int address, unsigned int sr);

/*

 *  The interrupt vector number associated with the clock tick device

 *  driver.

 */

#define CLOCK_VECTOR    8

/*

 *  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;

/*

 *  Clock_isrs is the number of clock ISRs until the next invocation of

 *  the RTEMS clock tick routine.  The clock tick device driver

 *  gets an interrupt once a millisecond and counts down until the

 *  length of time between the user configured microseconds per tick

 *  has passed.

 */

rtems_unsigned32 Clock_isrs;              /* ISRs until next tick */

/*

 * These are set by clock driver during its init

 */

rtems_device_major_number rtems_clock_major = ~0;

rtems_device_minor_number rtems_clock_minor;

void Clock_exit( void );

/* Write this to restart the Timer. Sets mode = 01,

   interrupts enabled, interrupt not pending, report

   at 200,000 (1 msec on 200 MHz CPU) */

static const unsigned int TTMR_RESET = 0x60030D40;

/*

 *  Isr Handler

 */

void Clock_isr(unsigned32 vector,

               unsigned32 pc,

               unsigned32 ear,

               unsigned32 sr)

{

  register int pending;

  register int value = 0x60002710;

  /* Was it us? */

  asm volatile ("l.mfspr %0,r0,0x4802 \n\t"  /* Read the PIC status */

                "l.andi  %0,%0,0x8    \n\t" : "=r" (pending));

  if(pending)

    {

      rtems_clock_tick();

      asm ("l.mtspr r0,%0,0x5000 \n\t" :: "r" (value));

    }

  if(old_handler)

    (*old_handler)(vector,pc,ear,sr);

}

/*

 *  Install_clock

 *

 *  Install a clock tick handler and reprograms the chip.  This

 *  is used to initially establish the clock tick.

 */

void Install_clock()

{

  unsigned32 tmp,sr,ttmr,ttcr;

  extern unsigned32 Or1k_Interrupt_Vectors[16];

  ttmr = TTMR_RESET;    /* Reset value */

  ttcr = 0;             /* Start at 0 */

  /*

   *  Initialize the clock tick device driver variables

   */

  /* Make sure the Timer (interrupt 3) is enabled and

     reports a high prority interrupt */

  asm volatile ("l.mfspr %0,r0,0x4800  \n\t"  /* Get the PIC mask */

                "l.ori   %0,%0,0x8     \n\t"  /* Enable int 3 */

                "l.mtspr r0,%0,0x4800  \n\t"  /* Write back mask */

                "l.mfspr %0,r0,0x4801  \n\t"  /* Get priority mask */

                "l.ori   %0,%0,0x8     \n\t"  /* Set us to high */

                "l.mtspr r0,%0,0x4801  \n\t"  /* Write back to PICPR */

                : "=r" (tmp));

  /* Generate a 1 kHz interrupt */

  asm volatile ("l.mfspr %0,r0,0x11 \n\t"    /* Get the current setting */

                "l.addi  %1,r0,-5   \n\t"

                "l.and   %1,%1,%0   \n\t"    /* Turn off interrupts */

                "l.mtspr r0,%1,0x11 \n\t"    /* Set it in SR */

                "l.mtspr r0,%2,0x5000\n\t"   /* Set TTMR */

                "l.mtspr r0,%3,0x5100\n\t"   /* Set TTCR */

                : "=&r" (sr), "=&r" (tmp) : "r" (ttmr), "r" (ttcr));

  old_handler = (void(*)(unsigned int,unsigned int,unsigned int,unsigned int))

    Or1k_Interrupt_Vectors[8];

  Or1k_Interrupt_Vectors[8] = (unsigned32)Clock_isr;

  asm volatile ("l.mtspr r0,%0,0x11\n\t":: "r" (sr));

  Clock_driver_ticks = 0;

  /*

   *  Schedule the clock cleanup routine to execute if the application exits.

   */

  atexit( Clock_exit );

}

/*

 *  Clean up before the application exits

 */

void Clock_exit( void )

{

  register int temp1;

  register int temp2;

  /* In the case of a fatal error, we should shut down

     all the interrupts so we don't get woken up again. */

  /* First, turn off the clock in the PIC */

  asm volatile ("l.mfspr %0,r0,0x4800  \n\t"  /* Get the PIC mask */

                "l.addi  %1,%1,-9      \n\t"  /* Create a mask to disable */

                "l.and   %0,%1,%0      \n\t"  /* Mask us out */

                "l.mtspr r0,%0,0x4800  \n\t"  /* Write back mask */

                "l.mfspr %0,r0,0x4801  \n\t"  /* Get priority mask */

                "l.and   %0,%1,%0      \n\t"  /* Set us to low */

                "l.mtspr r0,%0,0x4801  \n\t"  /* Write back to PICPR */

                : "=r" (temp1), "=r" (temp2));

  /* Now turn off the clock at the timer */

  asm volatile ("l.mtspr r0,r0,0x5000\n\t"   /* Clear TTMR */

                "l.mtspr r0,r0,0x5100\n\t"); /* Clear TTCR */

}

/*

 *  Clock_initialize

 *

 *  Device driver entry point for clock tick driver initialization.

 */

rtems_device_driver Clock_initialize(

  rtems_device_major_number major,

  rtems_device_minor_number minor,

  void *pargp

)

{

  Install_clock();

  /*

   * 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 == 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,0,0,0);

    }

    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;

}