rockbox/firmware/target/arm/tms320dm320/dsp/arm.c

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2008 by Catalin Patulea
 * Copyright (C) 2009 by Karl Kurbjun
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

#include "arm.h"
#include "registers.h"
#include "ipc.h"
#include "dma.h"

volatile struct ipc_message status;
volatile short int0_count;

#if defined(HAVE_DEBUG)
static int acked;
#endif

interrupt void handle_int0(void) {
    IFR = 1;
    int0_count++;
    
#if defined(HAVE_DEBUG)
    acked = 1;
#endif

    waiting = 0;
    
    if(dma0_stopped==0)
    {
        if(!(DMPREC&0x01))
        {
            /* Give the HPIB access to refill first */
            rebuffer();
            
            /* Start the MCBSP DMA */
            DMPREC |= 1;
            audiohw_start();
        }
        else
        {
            rebuffer();
        }
    }
    else
    {
        rebuffer();
    }
}

#if defined(HAVE_DEBUG)
static void startack(void)
{
    acked = 0;
    int_arm();
}

static void waitack(void)
{
    /* Wait until ARM has picked up data. */
    while (!acked) 
    {
        /* IDLE alone never seems to wake up :( */
        asm("        IDLE 1");
        asm("        NOP");
    }
}

void debugf(const char *fmt, ...) {
    va_list args;
    va_start(args, fmt);
    status.msg = MSG_DEBUGF;
    vsnprintf((char *)status.payload.debugf.buffer, sizeof(status), fmt, args);
    va_end(args);

    startack();
    waitack();

    acked = 2;
}
#endif

void int_arm(void)
{
    /*
     * ImageBuffer clock enable in ARM's MOD1 is ORed with clock enable
     * bit in CP_CLKC
     */

    /* Enable Image Buffer clock */
    CP_CLKC |= 1 << 0;
    /* Send interrupt to ARM */
    CP_INTC = 1 << 3;
    /* Disable Image Buffer clock */
    CP_CLKC &= ~(1 << 0);
}