init.c

freemodbus-v019.zip 是v0.19版本的代码

 /*
  * FreeModbus Libary: MCF5235 Demo Application
  * Copyright (C) 2006 Christian Walter <[e-mail]>
  * Parts of crt0.S Copyright (c) 1995, 1996, 1998 Cygnus Support
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  *
  * File: $Id: init.c,v 1.1 2006/05/14 21:59:16 wolti Exp $
  */

#include "mcf5xxx.h"
#include "mcf523x.h"

/* Function prototypes */
void            init_main( void );
static void     disable_interrupts( void );
static void     disable_watchdog_timer( void );
static void     disable_cache( void );
static void     init_ipsbar( void );
static void     init_basics( void );
static void     init_clock_config( void );
static void     init_chip_selects( void );
static void     init_bus_config( void );
static void     init_cache( void );
static void     init_eport( void );
static void     init_flexcan( void );
static void     init_power_management( void );
static void     init_dma_timers( void );
static void     init_interrupt_timers( void );
static void     init_watchdog_timers( void );
static void     init_pin_assignments( void );
static void     init_sdram_controller( void );
static void     init_interrupt_controller( void );

/*********************************************************************
* init_main - Main entry point for initialisation code               *
**********************************************************************/
void
init_main( void )
{
    /* Initialise base address of peripherals, VBR, etc */
    init_ipsbar(  );
    init_basics(  );
    init_clock_config(  );

    /* Disable interrupts, watchdog timer, cache */
    disable_interrupts(  );
    disable_watchdog_timer(  );
    disable_cache(  );

    /* Initialise individual modules */
    init_chip_selects(  );
    init_bus_config(  );
    init_cache(  );
    init_eport(  );
    init_flexcan(  );
    init_power_management(  );
    init_dma_timers(  );
    init_interrupt_timers(  );
    init_watchdog_timers(  );
    init_pin_assignments(  );
    init_sdram_controller(  );

    /* Initialise interrupt controller */
    init_interrupt_controller(  );
}

/*********************************************************************
* disable_interrupts - Disable all interrupt sources                 *
**********************************************************************/
static void
disable_interrupts( void )
{
    vuint8         *p;
    int             i;

    /* Set ICR008-ICR063 to 0x0 */
    p = ( vuint8 * ) & MCF_INTC0_ICR8;
    for( i = 8; i <= 63; i++ )
        *p++ = 0x0;

    /* Set ICR108-ICR163 to 0x0 */
    p = ( vuint8 * ) & MCF_INTC1_ICR8;
    for( i = 108; i <= 163; i++ )
        *p++ = 0x0;
}

/*********************************************************************
* disable_watchdog_timer - Disable system watchdog timer             *
**********************************************************************/
static void
disable_watchdog_timer( void )
{
    /* Disable Core Watchdog Timer */
    MCF_SCM_CWCR = 0;
}

/*********************************************************************
* disable_cache - Disable and invalidate cache                       *
**********************************************************************/
static void
disable_cache( void )
{
    asm( "move.l   #0x01000000,%d0" );
    asm( "movec    %d0,%cacr" );
}

/*********************************************************************
* init_basics - Configuration Information & VBR                      *
**********************************************************************/
static void
init_basics( void )
{
    extern void     ramvec_start;
    extern void     romvec_start;

    /* Transfer size not driven on SIZ[1:0] pins during external cycles 
       Processor Status (PST) and Debug Data (DDATA) functions disabled 
       Bus monitor disabled 
       Output pads configured for full strength 
     */
    MCF_CCM_CCR = ( 0x1 << 15 ) | MCF_CCM_CCR_BME;

    /* Exception vector table at $00000000 */
  asm( "move.l   %0,%%d0": :"i"( &romvec_start ) );
    asm( "movec    %d0,%vbr" );
}

/*********************************************************************
* init_clock_config - Clock Module                                   *
**********************************************************************/
static void
init_clock_config( void )
{
    /* Clock module uses normal PLL mode with 25.0000 MHz external reference (Fref) 
       MFD = 0, RFD = 1 
       Bus clock frequency = 25.00 MHz 
       Processor clock frequency = 2 x bus clock = 50.00 MHz 
       Frequency Modulation disabled 
       Loss of clock detection disabled 
       Reset/Interrupt on loss of lock disabled 
     */

    MCF_FMPLL_SYNCR = 0x00100000;       /* Set RFD=RFD+1 to avoid frequency overshoot */
    while( ( MCF_FMPLL_SYNSR & 0x08 ) == 0 )    /* Wait for PLL to lock */
        ;
    MCF_FMPLL_SYNCR = 0x00080000;       /* Set desired RFD */
    while( ( MCF_FMPLL_SYNSR & 0x08 ) == 0 )    /* Wait for PLL to lock */
        ;
}

/*********************************************************************
* init_ipsbar - Internal Peripheral System Base Address (IPSBAR)     *
**********************************************************************/
static void
init_ipsbar( void )
{
    /* Base address of internal peripherals (IPSBAR) = 0x40000000 

       Note: Processor powers up with IPS base address = 0x40000000 
       Write to IPS base + 0x00000000 to set new value 
     */
    *( vuint32 * ) 0x40000000 = ( vuint32 ) __IPSBAR + 1;       /* +1 for Enable */
}

/*********************************************************************
* init_chip_selects - Chip Select Module                             *
**********************************************************************/
static void
init_chip_selects( void )
{
    /* Chip Select 0 disabled (CSMR0[V] = 0) */
    MCF_CS_CSAR0 = 0;
    MCF_CS_CSMR0 = 0;
    MCF_CS_CSCR0 = MCF_CS_CSCR_IWS( 0xf ) | MCF_CS_CSCR_AA;

    /* Chip Select 1 disabled (CSMR1[V] = 0) */
    MCF_CS_CSAR1 = 0;
    MCF_CS_CSMR1 = 0;
    MCF_CS_CSCR1 = 0;

    /* Chip Select 2 disabled (CSMR2[V] = 0) */
    MCF_CS_CSAR2 = 0;
    MCF_CS_CSMR2 = 0;
    MCF_CS_CSCR2 = 0;

    /* Chip Select 3 disabled (CSMR3[V] = 0) */
    MCF_CS_CSAR3 = 0;
    MCF_CS_CSMR3 = 0;
    MCF_CS_CSCR3 = 0;

    /* Chip Select 4 disabled (CSMR4[V] = 0) */
    MCF_CS_CSAR4 = 0;
    MCF_CS_CSMR4 = 0;
    MCF_CS_CSCR4 = 0;

    /* Chip Select 5 disabled (CSMR5[V] = 0) */
    MCF_CS_CSAR5 = 0;
    MCF_CS_CSMR5 = 0;
    MCF_CS_CSCR5 = 0;

    /* Chip Select 6 disabled (CSMR6[V] = 0) */
    MCF_CS_CSAR6 = 0;
    MCF_CS_CSMR6 = 0;
    MCF_CS_CSCR6 = 0;

    /* Chip Select 7 disabled (CSMR7[V] = 0) */
    MCF_CS_CSAR7 = 0;
    MCF_CS_CSMR7 = 0;
    MCF_CS_CSCR7 = 0;
}

/*********************************************************************
* init_bus_config - Internal Bus Arbitration                         *
**********************************************************************/
static void
init_bus_config( void )
{
    /* Use round robin arbitration scheme 
       Assigned priorities (highest first): 
       Ethernet 
       DMA Controller 
       ColdFire Core 
       DMA bandwidth control disabled 
       Park on last active bus master 
     */
    MCF_SCM_MPARK = MCF_SCM_MPARK_M3_PRTY( 0x3 ) |
        MCF_SCM_MPARK_M2_PRTY( 0x2 ) | MCF_SCM_MPARK_M1_PRTY( 0x1 );
}

/*********************************************************************
* init_cache - Instruction/Data Cache                                *
**********************************************************************/
static void
init_cache( void )
{
    /* Instruction/Data cache disabled */
    asm( "move.l   #0x00000000, %d0" );
    asm( "movec    %d0,%cacr" );
}

/*********************************************************************
* init_eport - Edge Port Module (EPORT)                              *
**********************************************************************/
static void
init_eport( void )
{
    /* Pins 1-7 configured as GPIO inputs */
    MCF_EPORT_EPPAR = 0;
    MCF_EPORT_EPDDR = 0;
    MCF_EPORT_EPIER = 0;
}

/*********************************************************************
* init_flexcan - FlexCAN Module                                      *
**********************************************************************/
static void
init_flexcan( void )
{
    /* FlexCAN controller 0 disabled (CANMCR0[MDIS]=1) */
    MCF_CAN_IMASK0 = 0;
    MCF_CAN_RXGMASK0 = MCF_CAN_RXGMASK_MI( 0x1fffffff );
    MCF_CAN_RX14MASK0 = MCF_CAN_RX14MASK_MI( 0x1fffffff );
    MCF_CAN_RX15MASK0 = MCF_CAN_RX15MASK_MI( 0x1fffffff );
    MCF_CAN_CANCTRL0 = 0;
    MCF_CAN_CANMCR0 = MCF_CAN_CANMCR_MDIS |
        MCF_CAN_CANMCR_FRZ |
        MCF_CAN_CANMCR_HALT |
        MCF_CAN_CANMCR_SUPV | MCF_CAN_CANMCR_MAXMB( 0xf );

    /* FlexCAN controller 1 disabled (CANMCR1[MDIS]=1) */
    MCF_CAN_IMASK1 = 0;
    MCF_CAN_RXGMASK1 = MCF_CAN_RXGMASK_MI( 0x1fffffff );
    MCF_CAN_RX14MASK1 = MCF_CAN_RX14MASK_MI( 0x1fffffff );
    MCF_CAN_RX15MASK1 = MCF_CAN_RX15MASK_MI( 0x1fffffff );
    MCF_CAN_CANCTRL1 = 0;
    MCF_CAN_CANMCR1 = MCF_CAN_CANMCR_MDIS |
        MCF_CAN_CANMCR_FRZ |
        MCF_CAN_CANMCR_HALT |
        MCF_CAN_CANMCR_SUPV | MCF_CAN_CANMCR_MAXMB( 0xf );
}

/*********************************************************************
* init_power_management - Power Management                           *
**********************************************************************/
static void
init_power_management( void )
{
    /* On executing STOP instruction, processor enters RUN mode 
       Mode is exited when an interrupt of level 1 or higher is received 
     */
    MCF_SCM_LPICR = MCF_SCM_LPICR_ENBSTOP;
    MCF_CCM_LPCR = 0;
}

/*********************************************************************
* init_sdram_controller - SDRAM Controller                           *
**********************************************************************/
static void
init_sdram_controller( void )
{
    /* DRAM type is Synchronous (SDRAM) 
       SDRAM refresh timings: 
       Number of clocks spent in refresh state = 3 
       Refresh count = 511 (Refresh every 327.68 microseconds at 25.0 MHz bus clock) 
     */
    MCF_SDRAMC_DCR = MCF_SDRAMC_DCR_RC( 0x1ff );

    /* Memory block 0 not in use (DMR0[V] = 0) */
    MCF_SDRAMC_DMR0 = MCF_SDRAMC_DMR_BAM_256K;
    MCF_SDRAMC_DACR0 = 0;

    /* Memory block 1 not in use (DMR1[V] = 0) */
    MCF_SDRAMC_DMR1 = MCF_SDRAMC_DMR_BAM_256K;
    MCF_SDRAMC_DACR1 = 0;
}

/*********************************************************************
* init_dma_timers - DMA Timer Modules                                *
**********************************************************************/
static void
init_dma_timers( void )
{
    /* DMA Timer 0 disabled (DTMR0[RST] = 0) */
    MCF_TIMER_DTMR0 = 0;
    MCF_TIMER_DTXMR0 = 0;
    MCF_TIMER_DTRR0 = 0xffffffff;

    /* DMA Timer 1 disabled (DTMR1[RST] = 0) */
    MCF_TIMER_DTMR1 = 0;