vs1001k.c

含有完整TCP/IP PPP协议的嵌入式操作系统

/*
 * Copyright (C) 2003 by Pavel Chromy. All rights reserved.
 * Copyright (C) 2001-2003 by egnite Software GmbH. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY EGNITE SOFTWARE GMBH AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL EGNITE
 * SOFTWARE GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * For additional information see http://www.ethernut.de/
 * -
 *
 * This software has been inspired by all the valuable work done by
 * Jesper Hansen <[e-mail]>. Many thanks for all his help.
 */

/*
 * $Log: vs1001k.c,v $
 * Revision 1.1  2003/07/21 18:09:51  haraldkipp
 * Backup of old driver
 *
 * Revision 1.1.1.1  2003/05/09 14:40:58  haraldkipp
 * Initial using 3.2.1
 *
 * Revision 1.12  2003/05/06 18:35:21  harald
 * ICCAVR port
 *
 * Revision 1.11  2003/04/21 16:43:54  harald
 * Added more comments.
 * Avoid initializing static globals to zero.
 * New function VsSdiWrite/_P checks DREQ
 * Removed decoder interrupt en/disable from low level routines.
 * Keep decoder in reset state until ports have been initialized.
 * Do not send initial zero bytes as the datasheet recommends.
 * A single nop is sufficient delay during reset active.
 * Clear interrupt flag after reset to avoid useless interrupt.
 * Available buffer size corrected.
 * New function to read header information.
 * New function invokes decoder memory test.
 * Beep makes use of VsSdiWrite.
 *
 * Revision 1.10  2003/04/18 14:46:08  harald
 * Copyright update by the maintainer, after none of the original code had
 * been left. We have a clean BSD licence now.
 * This release had been prepared by Pavel Chromy.
 * BSYNC vs. transfer in progress issue in VsSdiPutByte().
 * Fixed possible transfer in progress issue in VsPlayerFeed().
 * HW reset may be forced by VS_SM_RESET mode bit
 *
 * Revision 1.9  2003/04/07 20:29:20  harald
 * Redesigned by Pavel Chromy
 *
 * Revision 1.9  2003/04/04 15:01:00  mac
 * VS_STATUS_EMTY is reported correctly.
 *
 * Revision 1.9  2003/02/14 13:39:00  mac
 * Several serious bugs fixed,
 * interrupt routine completely remade.
 * Unreliable spurious interrupts detection removed.
 * Mpeg frame detection removed.
 * Watermark check removed (this was rather limiting)
 * Can be optionaly compiled not to use SPI
 *
 * Revision 1.8  2003/02/04 17:50:55  harald
 * Version 3 released
 *
 * Revision 1.7  2003/01/14 16:15:19  harald
 * Sending twice the number of zeros to end MP3 stream.
 * Check for spurious interrupts to detect hanging chip.
 * Simpler portable inline assembler for short delays.
 *
 * Revision 1.6  2002/11/02 15:15:13  harald
 * Library dependencies removed
 *
 * Revision 1.5  2002/09/15 16:44:14  harald
 * *** empty log message ***
 *
 * Revision 1.4  2002/08/16 17:49:02  harald
 * First public release
 *
 * Revision 1.3  2002/06/26 17:29:08  harald
 * First pre-release with 2.4 stack
 *
 */

#include <sys/atom.h>
#include <sys/event.h>
#include <sys/timer.h>
#include <sys/heap.h>

#include <dev/irqreg.h>
#include <dev/vs1001k.h>

/*!
 * \addtogroup xgVs1001
 */
/*@{*/


static volatile u_char vs_status = VS_STATUS_STOPPED;
static volatile u_short vs_flush;

static u_char *vs_databuff;
static u_char *vs_dataend;

static u_char *vs_writeptr;
static u_char *volatile vs_readptr;


/*
 * \brief Write a byte to the VS1001 data interface.
 *
 * The caller is responsible for checking the DREQ line. Also make sure,
 * that decoder interrupts are disabled.
 *
 * \param b Byte to be shifted to the decoder's data interface.
 */
static INLINE void VsSdiPutByte(u_char b)
{
#ifdef VS_NOSPI
    u_char mask = 0x80;
    sbi(VS_BSYNC_PORT, VS_BSYNC_BIT);
    while (mask) {
        if (b & mask)
            sbi(VS_SI_PORT, VS_SI_BIT);
        else
            cbi(VS_SI_PORT, VS_SI_BIT);

        sbi(VS_SS_PORT, VS_SS_BIT);
        mask >>= 1;
        cbi(VS_SS_PORT, VS_SS_BIT);
        cbi(VS_BSYNC_PORT, VS_BSYNC_BIT);
    }
#else
    /* Wait for previous SPI transfer to finish. */
    loop_until_bit_is_set(SPSR, SPIF);
    sbi(VS_BSYNC_PORT, VS_BSYNC_BIT);
    outp(b, SPDR);
    _NOP();
    _NOP();
    _NOP();
    _NOP();
    cbi(VS_BSYNC_PORT, VS_BSYNC_BIT);
#endif
}

/*!
 * \brief Write a specified number of bytes to the VS1001 data interface.
 *
 * This function will check the DREQ line. Decoder interrupts must have 
 * been disabled before calling this function.
 */
static int VsSdiWrite(CONST u_char * data, u_short len)
{
    u_short try = 5000;

    while (len--) {
        while (try-- && bit_is_clear(VS_DREQ_PIN, VS_DREQ_BIT));
        VsSdiPutByte(*data);
        data++;
    }
    return try ? 0 : -1;
}

/*!
 * \brief Write a specified number of bytes from program space to the 
 *        VS1001 data interface.
 *
 * This function is similar to VsSdiWrite() except that the data is 
 * located in program space.
 */
static int VsSdiWrite_P(PGM_P data, u_short len)
{
    u_short try = 5000;

    while (len--) {
        while (try-- && bit_is_clear(VS_DREQ_PIN, VS_DREQ_BIT));
        VsSdiPutByte(PRG_RDB(data));
        data++;
    }
    return try ? 0 : -1;
}

/*!
 * \brief Write a byte to the serial control interface.
 *
 * Decoder interrupts must have been disabled and the decoder chip
 * select must have been enabled before calling this function.
 */
static INLINE void VsSciPutByte(u_char data)
{
    u_char mask = 0x80;

    /*
     * Loop until all 8 bits are processed.
     */
    while (mask) {

        /* Set data line. */
        if (data & mask)
            sbi(VS_SI_PORT, VS_SI_BIT);
        else
            cbi(VS_SI_PORT, VS_SI_BIT);

        /* Toggle clock and shift mask. */
        sbi(VS_SCK_PORT, VS_SCK_BIT);
        mask >>= 1;
        cbi(VS_SCK_PORT, VS_SCK_BIT);
    }
}

/*!
 * \brief Read a byte from the serial control interface.
 *
 * Decoder interrupts must have been disabled and the decoder chip
 * select must have been enabled before calling this function.
 */
static INLINE u_char VsSciGetByte(void)
{
    u_char mask = 0x80;
    u_char data = 0;

    /*
     * Loop until all 8 bits are processed.
     */
    while (mask) {
        /* Toggle clock and get the data. */
        sbi(VS_SCK_PORT, VS_SCK_BIT);
        if (bit_is_set(VS_SO_PIN, VS_SO_BIT))
            data |= mask;
        mask >>= 1;
        cbi(VS_SCK_PORT, VS_SCK_BIT);
    }
    return data;
}

/*!
 * \brief Write to a decoder register.
 *
 * Decoder interrupts must have been disabled before calling this function.
 */
static void VsRegWrite(u_char reg, u_short data)
{
    /* Select chip. */
    cbi(VS_XCS_PORT, VS_XCS_BIT);

#ifndef VS_NOSPI
    /* Disable SPI */
    cbi(SPCR, SPE);
#endif

    VsSciPutByte(VS_OPCODE_WRITE);
    VsSciPutByte(reg);
    VsSciPutByte((u_char) (data >> 8));
    VsSciPutByte((u_char) data);

#ifndef VS_NOSPI
    /* Re-enable SPI. Hint given by Jesper Hansen. */
    outp(BV(MSTR) | BV(SPE), SPCR);
    outp(inp(SPSR), SPSR);
#endif

    /* Deselect chip. */
    sbi(VS_XCS_PORT, VS_XCS_BIT);
}

/*
 * \brief Read from a register.
 *
 * Decoder interrupts must have been disabled before calling this function.
 * 
 * \return Register contents.
 */
static u_short VsRegRead(u_char reg)
{
    u_short data;

    /* Disable interrupts and select chip. */
    cbi(EIMSK, VS_DREQ_BIT);
    cbi(VS_XCS_PORT, VS_XCS_BIT);

#ifndef VS_NOSPI
    /* Disable SPI. */
    cbi(SPCR, SPE);
#endif

    VsSciPutByte(VS_OPCODE_READ);
    VsSciPutByte(reg);
    data = VsSciGetByte() << 8;
    data |= VsSciGetByte();

#ifndef VS_NOSPI
    /* Re-enable SPI. Changed due to a hint by Jesper. */
    outp(BV(MSTR) | BV(SPE), SPCR);
    outp(inp(SPSR), SPSR);
#endif

    /* Deselect chip and enable interrupts. */
    sbi(VS_XCS_PORT, VS_XCS_BIT);
    sbi(EIMSK, VS_DREQ_BIT);

    return data;
}

/*
 * \brief Feed the decoder with data.
 *
 * This function serves two purposes: 
 * - It is called by VsPlayerKick() to initially fill the decoder buffer.
 * - It is used as an interrupt handler for the decoder.
 */
static void VsPlayerFeed(void *arg)
{
    u_char j;

    /* Cancel interrupt if not running. */
    if (vs_status != VS_STATUS_RUNNING)
        return;

    /* We may feed 32 bytes to the decoder. */
    if (bit_is_set(VS_DREQ_PIN, VS_DREQ_BIT))
        j = 32;
    else
        j = 0;

    /* 
     * Feed the decoder until its buffer is full. 
     */
    while (j--) {

        /* Is main buffer empty? */
        if (vs_readptr == vs_writeptr) {
            if (vs_flush) {
                /* Auto flush the internal VS buffer. */
                VsSdiPutByte(0);
                if (--vs_flush == 0) {
                    /* Decoder internal buffer is flushed. */
                    vs_status = VS_STATUS_EMPTY;
                    break;
                }
            } else {
                /* End of stream. */
                vs_status = VS_STATUS_EOF;
                break;
            }
        }
        /* We have some data in the buffer, feed it. */
        else {
            VsSdiPutByte(*vs_readptr);
            if (++vs_readptr == vs_dataend)
                vs_readptr = vs_databuff;
        }

        /* If DREQ is high, allow 31 bytes to be sent, SPI transfer may 
           still be in progress, which is the 32nd byte. */
        if (bit_is_set(VS_DREQ_PIN, VS_DREQ_BIT))
            j = 31;
    }
}

/*!
 * \brief Start playback.
 *
 * This routine will send the first MP3 data bytes to the
 * decoder, until it is completely filled. The data buffer
 * should have been filled before calling this routine.
 *
 * \return 0 on success, -1 otherwise.
 */
int VsPlayerKick(void)
{
    cbi(EIMSK, VS_DREQ_BIT);

    /*
     * Start feeding the decoder with data and
     * enable interrupts.
     */
    vs_status = VS_STATUS_RUNNING;
    VsPlayerFeed(NULL);

    sbi(EIMSK, VS_DREQ_BIT);
    return 0;
}

/*!
 * \brief Stops the playback.
 *
 * This routine will stops the MP3 playback, VsPlayerKick() may be used 
 * to resume the playback.
 *