Subversion Repositories openrisc_2011-10-31

/*

 * Timer_init()

 *

 * ATTENTION: AS MC68349 has no built-in Timer, the following code doesn't work

 *            in a MC68349. You can't use FIFO full mode for the moment, but

 *            it should be easy to fix this by using an external timer

 *

 * Use TIMER 1 for TIMEOUT when using FIFO FULL mode in UART driver

 * Use TIMER 2 for timing test suites

 *

 * Geoffroy Montel

 * France Telecom - CNET/DSM/TAM/CAT

 * 4, rue du Clos Courtel

 * 35512 CESSON-SEVIGNE

 * FRANCE

 *

 * e-mail: g_montel@yahoo.com

 *

 *  $Id: timer.c,v 1.2 2001-09-27 12:00:07 chris Exp $

 */

/*

 *

 *  Input parameters:  NONE

 *

 *  Output parameters:  NONE

 *

 *  NOTE: It is important that the timer start/stop overhead be

 *        determined when porting or modifying this code.

 *

 *  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 <rtems.h>

#include <bsp.h>

#include <m340uart.h>

#include <m340timer.h>

#include <m68340.h>

#define TIMER1_VECTOR 122

#define TIMER1_IRQ_LEVEL 5

#define TIMER1_INTERRUPT_ARBITRATION 5

#define TIMER2_VECTOR 123

#define TIMER2_IRQ_LEVEL 4

#define TIMER2_INTERRUPT_ARBITRATION 4

#define CLOCK_SPEED 25          /* in Mhz */

#define max(a,b) (((a)>(b)) ? (a) : (b))

void (*Restart_Fifo_Full_A_Timer)();

void (*Restart_Check_A_Timer)();

void (*Restart_Fifo_Full_B_Timer)();

void (*Restart_Check_B_Timer)();

int preload = 0;

/******************************************************

  Name: __Restart_Fifo_Full_Timer

  Input parameters: -

  Output parameters: -

  Description: when a character is received, sets

               the TIMER to raise an interrupt at

               TIMEOUT.

               It's necessary to prevent from not

               getting n-1 characters (with n the

               Uart Fifo size)

 *****************************************************/

void __Restart_Fifo_Full_Timer (void)

{

 TSR1 |= m340_TO;

 TCR1 &= ~m340_CPE;

 WPREL11 = preload;

 TCR1 |= m340_CPE;

}

/******************************************************

  Name: __Restart_Fifo_Full_Timer

  Input parameters: -

  Output parameters: -

  Description: when no character has been received

               recently, check now and then if whether

               a there's a character in the FIFO

 *****************************************************/

void __Restart_Check_Timer (void)

{

 TSR1 |= m340_TO;

 TCR1 &= ~m340_CPE;

 WPREL11 = 0xFFFF;

 TCR1 |= m340_CPE;

}

/******************************************************

  Name: __do_nothing

  Input parameters: -

  Output parameters: -

  Description: we always restart the fifo full timer

               with a call to Restart_*_Timer

               if we do not use FIFO full, Restart_*_Timer

               are set to do __do_nothing

 *****************************************************/

void __do_nothing (void)

{

}

#define Fifo_Full_on_A (m340_uart_config[UART_CHANNEL_A].rx_mode==UART_FIFO_FULL && m340_uart_config[UART_CHANNEL_A].enable && m340_uart_config[UART_CHANNEL_A].mode==UART_INTERRUPTS)

#define Fifo_Full_on_B (m340_uart_config[UART_CHANNEL_B].rx_mode==UART_FIFO_FULL && m340_uart_config[UART_CHANNEL_B].enable && m340_uart_config[UART_CHANNEL_B].mode==UART_INTERRUPTS)

/******************************************************

  Name: Fifo_Full_Timer_initialize

  Input parameters: -

  Output parameters: -

  Description: initialize Timer 1 for FIFO full mode

 *****************************************************/

void Fifo_Full_Timer_initialize (void)

{

   float max_baud_rate;

   int prescaler_output_tap = -1;

   int nb_of_clock_ticks = 0;

   /*

    *  USE TIMER 1 for UART FIFO FULL mode

    */

   if ( Fifo_Full_on_A || Fifo_Full_on_B )

      {

        /* Disable the timer */

        TCR1 &= ~m340_SWR;

        /* Reset the interrupts */

        TSR1 &= ~(m340_TO | m340_TG | m340_TC);

        /* Init the stop bit for normal operation, ignore FREEZE, user privileges,

           set interrupt arbitration */

        TMCR1 = TIMER1_INTERRUPT_ARBITRATION;

        /* interrupt priority level and interrupt vector */

        TIR1 = TIMER1_VECTOR | (TIMER1_IRQ_LEVEL << 8);

        /* compute prescaler */

        if ( Fifo_Full_on_A && Fifo_Full_on_B)

                max_baud_rate = max(m340_uart_config[UART_CHANNEL_A].rx_baudrate, m340_uart_config[UART_CHANNEL_B].rx_baudrate);

        else if ( Fifo_Full_on_A )

                max_baud_rate = m340_uart_config[UART_CHANNEL_A].rx_baudrate;

             else max_baud_rate = m340_uart_config[UART_CHANNEL_B].rx_baudrate;

        /* find out config */

        nb_of_clock_ticks = (10/max_baud_rate)*(CLOCK_SPEED*1000000)*1.2;

        if (nb_of_clock_ticks < 0xFFFF) {

           preload = nb_of_clock_ticks;

           prescaler_output_tap = -1;

        } else if (nb_of_clock_ticks/2 < 0xFFFF) {

           preload = nb_of_clock_ticks/2;

           prescaler_output_tap = m340_Divide_by_2;

        } else if (nb_of_clock_ticks/4 < 0xFFFF) {

           preload = nb_of_clock_ticks/4;

           prescaler_output_tap = m340_Divide_by_4;

        } else if (nb_of_clock_ticks/8 < 0xFFFF) {

           preload = nb_of_clock_ticks/8;

           prescaler_output_tap = m340_Divide_by_16;

        } else if (nb_of_clock_ticks/16 < 0xFFFF) {

           preload = nb_of_clock_ticks/16;

           prescaler_output_tap = m340_Divide_by_16;

        } else if (nb_of_clock_ticks/32 < 0xFFFF) {

           preload = nb_of_clock_ticks/32;

           prescaler_output_tap = m340_Divide_by_32;

        } else if (nb_of_clock_ticks/64 < 0xFFFF) {

           preload = nb_of_clock_ticks/64;

           prescaler_output_tap = m340_Divide_by_64;

        } else if (nb_of_clock_ticks/128 < 0xFFFF) {

           preload = nb_of_clock_ticks/128;

           prescaler_output_tap = m340_Divide_by_128;

        } else if (nb_of_clock_ticks/256 < 0xFFFF) {

           preload = nb_of_clock_ticks/256;

           prescaler_output_tap = m340_Divide_by_256;

        }

        /* Input Capture/Output Compare (ICOC) */

        TCR1 = m340_SWR | m340_TO_Enabled | m340_ICOC;

        if (prescaler_output_tap!=-1) TCR1 |= prescaler_output_tap | m340_PSE;

        /* install interrupt vector */

        {

         rtems_isr_entry old_handler;

         rtems_status_code sc;

         extern void _Debug_ISR_Handler_Console(void);

         sc = rtems_interrupt_catch (InterruptHandler,

                                     TIMER1_VECTOR,

                                     &old_handler);

         /* uncomment this if you want to pass control to your own ISR handler

            it may be usefull to do so to check for performances with an oscilloscope */

         /*

         {

          proc_ptr ignored;

          _CPU_ISR_install_raw_handler( TIMER1_VECTOR, _Debug_ISR_Handler_Console, &ignored );

         }

         */

        }

       } /* fifo full mode on a uart */

       /* install routines */

       Restart_Check_A_Timer = Fifo_Full_on_A ? __Restart_Check_Timer : __do_nothing;

       Restart_Fifo_Full_A_Timer = Fifo_Full_on_A ? __Restart_Fifo_Full_Timer : __do_nothing;

       Restart_Check_B_Timer = Fifo_Full_on_B ? __Restart_Check_Timer : __do_nothing;

       Restart_Fifo_Full_B_Timer = Fifo_Full_on_B ? __Restart_Fifo_Full_Timer : __do_nothing;

       /* start checking timer */

       Restart_Check_A_Timer();

       Restart_Check_B_Timer();

}

/******************************************************

  Name: Timer_initialize

  Input parameters: -

  Output parameters: -

  Description: init Timer for timing test suites

 *****************************************************/

void Timer_initialize (void)

{

        /* Disable the timer */

        TCR2 &= ~m340_SWR;

        /* Reset the interrupts */

        TSR2 &= ~(m340_TO | m340_TG | m340_TC);

        /* Init the stop bit for normal operation, ignore FREEZE, user privileges,

           set interrupt arbitration */

        TMCR1 = TIMER2_INTERRUPT_ARBITRATION;

        /* interrupt priority level and interrupt vector */

        TIR1 = TIMER2_VECTOR | (TIMER2_IRQ_LEVEL << 8);

        /* Init the stop bit for normal operation, ignore FREEZE, user privileges,

           set interrupt arbitration */

        TMCR2 = TIMER2_INTERRUPT_ARBITRATION;

        /* Preload register 1 */

        WPREL21 = 0xFFFF;

        /* Input Capture/Output Compare (ICOC) */

        TCR2 = m340_SWR | m340_ICOC | m340_PSE | m340_Divide_by_16 | m340_CPE;

}

/******************************************************

  Name: Read_timer

  Input parameters: -

  Output parameters: -

  Description: Return timer value in microsecond units

 *****************************************************/

int

Read_timer (void)

{

 /* there's CLOCK_SPEED / 16 micro seconds between two timer register decrement */

 return (((0xFFFF - TCNTR2) * CLOCK_SPEED) / 16);

}

/******************************************************

  Name: Empty_function

  Input parameters: -

  Output parameters: -

  Description: Empty function call used in loops to

               measure basic cost of looping

               in Timing Test Suite.

 *****************************************************/

rtems_status_code

Empty_function (void)

{

        return RTEMS_SUCCESSFUL;

}

/******************************************************

  Name: Set_find_average_overhead

  Input parameters: -

  Output parameters: -

  Description: -

 *****************************************************/

void

Set_find_average_overhead(rtems_boolean find_flag)

{

}