net_timer.c

motorola 针对coldfire 5275 评估板的Dbug bootloader源程序

/*
 * File:        net_timer.c
 * Purpose:     Provide a timer use by the dBUG network as a timeout
 *              indicator
 *
 * Notes:
 */
#include "src/include/dbug.h"
#include "src/cpu/coldfire/mcf548x/net_timer.h"

#ifdef DBUG_NETWORK

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

static NET_TIMER net_timer[4] = {{0, 0, 0, 0, 0, 0, 0},
                                 {0, 0, 0, 0, 0, 0, 0},
                                 {0, 0, 0, 0, 0, 0, 0},
                                 {0, 0, 0, 0, 0, 0, 0}};

/********************************************************************/
int
timer_default_isr(void *not_used, NET_TIMER *t)
{
    (void) not_used;
    
    /* 
     * Clear the pending event 
     */
    MCF_GPT_GMS(t->ch) = 0;

    /*
     * Clear the reference - the desired seconds have expired
     */
    t->reference = 0;

    return 1;
}
/********************************************************************/
void
timer_irq_enable(uint8 ch)
{
    /*
     * Setup the appropriate ICR
     */
    MCF_INTC_ICRn(TIMER_VECTOR(ch)-64) = (uint8)(0
        | MCF_INTC_ICRn_IP(net_timer[ch].pri)
        | MCF_INTC_ICRn_IL(net_timer[ch].lvl));

    /*
     * Unmask the FEC interrupt in the interrupt controller
     */
    if (ch == 3)
        MCF_INTC_IMRH &= ~MCF_INTC_IMRH_INT_MASK59;
    else if (ch == 2)
        MCF_INTC_IMRH &= ~MCF_INTC_IMRH_INT_MASK60;
    else if (ch == 1)
        MCF_INTC_IMRH &= ~MCF_INTC_IMRH_INT_MASK61;
    else
        MCF_INTC_IMRH &= ~MCF_INTC_IMRH_INT_MASK62;
}
/********************************************************************/
uint32
timer_set_secs(uint8 ch, uint32 secs)
{
    uint16 timeout;
    
    /*
     * Reset the timer
     */
    MCF_GPT_GMS(ch) = 0;

    /* 
     * Get the timeout in seconds 
     */
    timeout = (uint16)(secs * net_timer[ch].cnt);

    /*
     * Set the reference indicating that we have not yet reached the
     * desired timeout
     */
    net_timer[ch].reference = 1;

    /*
     * Enable timer interrupt to the processor
     */
    timer_irq_enable(ch);

    /*
     * Enable the timer using the pre-calculated values
     */
    MCF_GPT_GCIR(ch) = (0
                        | MCF_GPT_GCIR_CNT(timeout)
                        | MCF_GPT_GCIR_PRE(net_timer[ch].pre)
                        );
    MCF_GPT_GMS(ch) = net_timer[ch].gms;

    return TRUE;
}
/********************************************************************/
uint32
timer_get_reference(uint8 ch)
{   
    return (uint32)net_timer[ch].reference;
}
/********************************************************************/
uint32
timer_init(uint8 ch, uint8 lvl, uint8 pri)
{
    /* 
     * Initialize the timer to expire after one second
     * 
     * This routine should only be called by the project (board) specific
     * initialization code.
     */
    ASSERT((ch <= 3) && (lvl <= 7) && (lvl >= 1) && (pri <= 7));

    /*
     * Reset the timer
     */
    MCF_GPT_GMS(ch) = 0;

    /* 
     * Save off the channel, and interrupt lvl/pri information
     */
    net_timer[ch].ch = ch;
    net_timer[ch].lvl = lvl;
    net_timer[ch].pri = pri;

    /*
     * Register the timer interrupt handler
     */
    if (!isr_register_handler(ISR_DBUG_ISR, 
                              TIMER_VECTOR(ch), 
                              (int (*)(void*,void*))timer_default_isr,
                              NULL, 
                              (void *)&net_timer[ch])
                              )
    {
        return FALSE;
    }

    /*
     * Calculate the require CNT value to get a 1 second timeout
     *
     * 1 sec = CNT * Clk Period * PRE
     * CNT = 1 sec / (Clk Period * PRE)
     * CNT = Clk Freq / PRE
     *
     * The system clock frequency is defined as SYSTEM_CLOCK and
     * is given in MHz. We need to multiple it by 1000000 to get the 
     * true value.  If we assume PRE to be the maximum of 0xFFFF, 
     * then the CNT value needed to achieve a 1 second timeout is 
     * given by:
     *
     * CNT = SYSTEM_CLOCK * (1000000/0xFFFF)
     */
    net_timer[ch].pre = 0xFFFF;
    net_timer[ch].cnt = (uint16)(SYSTEM_CLOCK * (1000000/0xFFFF));

    /* 
     * Save off the appropriate mode select register value 
     */
    net_timer[ch].gms = (0 
                     | MCF_GPT_GMS_TMS_GPIO
                     | MCF_GPT_GMS_IEN
                     | MCF_GPT_GMS_SC
                     | MCF_GPT_GMS_CE
                     );

    return TRUE;
}
/********************************************************************/

#endif /* #ifdef DBUG_NETWORK */