rockbox/firmware/mpeg.c

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2002 by Linus Nielsen Feltzing
 *
 * All files in this archive are subject to the GNU General Public License.
 * See the file COPYING in the source tree root for full license agreement.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/
#include <stdbool.h>
#include "i2c.h"
#include "mas.h"
#include "dac.h"
#include "sh7034.h"
#include "system.h"
#include "debug.h"
#include "kernel.h"
#include "thread.h"
#include "panic.h"
#include "file.h"

#define MPEG_STACK_SIZE 0x2000
#define MPEG_CHUNKSIZE  0x20000
#define MPEG_LOW_WATER  0x30000

#define MPEG_PLAY         1
#define MPEG_STOP         2
#define MPEG_PAUSE        3
#define MPEG_RESUME       4
#define MPEG_NEED_DATA    100

static unsigned int bass_table[] =
{
    0,
    0x800,   /* 1dB */
    0x10000, /* 2dB */
    0x17c00, /* 3dB */
    0x1f800, /* 4dB */
    0x27000, /* 5dB */
    0x2e400, /* 6dB */
    0x35800, /* 7dB */
    0x3c000, /* 8dB */
    0x42800, /* 9dB */
    0x48800, /* 10dB */
    0x4e400, /* 11dB */
    0x53800, /* 12dB */
    0x58800, /* 13dB */
    0x5d400, /* 14dB */
    0x61800  /* 15dB */
};

static unsigned int treble_table[] =
{
    0,
    0x5400,  /* 1dB */
    0xac00,  /* 2dB */
    0x10400, /* 3dB */
    0x16000, /* 4dB */
    0x1c000, /* 5dB */
    0x22400, /* 6dB */
    0x28400, /* 7dB */
    0x2ec00, /* 8dB */
    0x35400, /* 9dB */
    0x3c000, /* 10dB */
    0x42c00, /* 11dB */
    0x49c00, /* 12dB */
    0x51800, /* 13dB */
    0x58400, /* 14dB */
    0x5f800  /* 15dB */
};

static unsigned char fliptable[] =
{
    0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, 
    0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0, 
    0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, 
    0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8, 
    0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, 
    0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4, 
    0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, 
    0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc, 
    0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, 
    0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2, 
    0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, 
    0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa, 
    0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, 
    0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6, 
    0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, 
    0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe, 
    0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, 
    0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1, 
    0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, 
    0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9, 
    0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, 
    0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5, 
    0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, 
    0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd, 
    0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, 
    0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3, 
    0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, 
    0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb, 
    0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, 
    0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7, 
    0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, 
    0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff
};

static struct event_queue mpeg_queue;
static int mpeg_stack[MPEG_STACK_SIZE/sizeof(int)];

/* defined in linker script */
extern unsigned char mp3buf[];
extern unsigned char mp3end[];

static int mp3buflen;
static int mp3buf_write;
static int mp3buf_read;

static int last_dma_chunk_size;

static bool dma_on;  /* The DMA is active */
static bool playing; /* We are playing an MP3 stream */
static bool filling; /* We are filling the buffer with data from disk */

static int mpeg_file = -1;

static void mas_poll_start(int interval_in_ms)
{
    unsigned int count;

    count = FREQ / 1000 / 8 * interval_in_ms;

    if(count > 0xffff)
    {
        panicf("Error! The MAS poll interval is too long (%d ms)\n",
               interval_in_ms);
        return;
    }
    
    /* We are using timer 1 */
    
    TSTR &= ~0x02; /* Stop the timer */
    TSNC &= ~0x02; /* No synchronization */
    TMDR &= ~0x02; /* Operate normally */

    TCNT1 = 0;   /* Start counting at 0 */
    GRA1 = count;
    TCR1 = 0x23; /* Clear at GRA match, sysclock/8 */

    /* Enable interrupt on level 2 */
    IPRC = (IPRC & ~0x000f) | 0x0002;
    
    TSR1 &= ~0x02;
    TIER1 = 0xf9; /* Enable GRA match interrupt */

    TSTR |= 0x02; /* Start timer 2 */
}

static void init_dma(void)
{
    SAR3 = (unsigned int) mp3buf + mp3buf_read;
    DAR3 = 0x5FFFEC3;
    CHCR3 &= ~0x0002; /* Clear interrupt */
    CHCR3 = 0x1504; /* Single address destination, TXI0, IE=1 */
    last_dma_chunk_size = MIN(65536, mp3buf_write - mp3buf_read);
    DTCR3 = last_dma_chunk_size & 0xffff;
    DMAOR = 0x0001; /* Enable DMA */
    CHCR3 |= 0x0001; /* Enable DMA IRQ */
}

static void start_dma(void)
{
    SCR0 |= 0x80;
    dma_on = true;
}

static void stop_dma(void)
{
    SCR0 &= 0x7f;
    dma_on = false;
}

static void dma_tick(void)
{
    /* Start DMA if it isn't running */
    if(playing && !dma_on)
    {
        if(PBDR & 0x4000)
        {
            if(!(SCR0 & 0x80))
                start_dma();
        }
    }
}

static void bitswap(unsigned char *data, int length)
{
    int i = length;
    while(i--)
    {
        data[i] = fliptable[data[i]];
    }
}

static void reset_mp3_buffer(void)
{
    mp3buf_read = 0;
    mp3buf_write = 0;
}

#pragma interrupt
void IRQ6(void)
{
    stop_dma();
}

#pragma interrupt
void DEI3(void)
{
    int unplayed_space_left;
    int space_until_end_of_buffer;

    if(playing)
    {
        mp3buf_read += last_dma_chunk_size;
        if(mp3buf_read >= mp3buflen)
            mp3buf_read = 0;
    
        unplayed_space_left = mp3buf_write - mp3buf_read;
        if(unplayed_space_left < 0)
            unplayed_space_left = mp3buflen + unplayed_space_left;

        space_until_end_of_buffer = mp3buflen - mp3buf_read;
        
        if(!filling && unplayed_space_left < MPEG_LOW_WATER)
        {
            filling = true;
            queue_post(&mpeg_queue, MPEG_NEED_DATA, 0);
        }
        
        if(unplayed_space_left)
        {
            last_dma_chunk_size = MIN(65536, unplayed_space_left);
            last_dma_chunk_size = MIN(last_dma_chunk_size, space_until_end_of_buffer);
            DTCR3 = last_dma_chunk_size & 0xffff;
            SAR3 = (unsigned int)mp3buf + mp3buf_read;
        }
        else
        {
            DEBUGF("No more MP3 data. Stopping.\n");
            CHCR3 = 0; /* Stop DMA interrupt */
        }
    }

    CHCR3 &= ~0x0002; /* Clear DMA interrupt */
}

#pragma interrupt
void IMIA1(void)
{
    dma_tick();
    TSR1 &= ~0x01;
}

static int new_file(void)
{
    char *trackname;

    trackname = peek_next_track(0);
    if ( !trackname )
        return -1;

    debugf("playing %s\n", trackname);
    mpeg_file = open(trackname, O_RDONLY);
    if(mpeg_file < 0)
    {
        debugf("Couldn't open file\n");
        return -1;
    }
    return 0;
}

static void mpeg_thread(void)
{
    struct event ev;
    int len;
    int free_space_left;
    int amount_to_read;
    bool play_pending;

    play_pending = false;
    playing = false;

    while(1)
    {
        DEBUGF("S\n");
        queue_wait(&mpeg_queue, &ev);
        switch(ev.id)
        {
            case MPEG_PLAY:
                DEBUGF("MPEG_PLAY %s\n",ev.data);
                /* Stop the current stream */
                play_pending = false;
                playing = false;
                stop_dma();

                reset_mp3_buffer();

                mpeg_file = open((char*)ev.data, O_RDONLY);
                if(mpeg_file < 0)
                {
                    DEBUGF("Couldn't open %s\n",ev.data);
                    break;
                }
                
                /* Make it read more data */
                filling = true;
                queue_post(&mpeg_queue, MPEG_NEED_DATA, 0);

                /* Tell the file loading code that we want to start playing
                   as soon as we have some data */
                play_pending = true;
                break;

            case MPEG_STOP:
                DEBUGF("MPEG_STOP\n");
                /* Stop the current stream */
                playing = false;
                stop_dma();
                break;

            case MPEG_PAUSE:
                DEBUGF("MPEG_PAUSE\n");
                /* Stop the current stream */
                playing = false;
                stop_dma();
                break;

            case MPEG_RESUME:
                DEBUGF("MPEG_RESUME\n");
                /* Stop the current stream */
                playing = true;
                start_dma();
                break;

            case MPEG_NEED_DATA:
                free_space_left = mp3buf_read - mp3buf_write;

                /* We interpret 0 as "empty buffer" */
                if(free_space_left <= 0)
                    free_space_left = mp3buflen + free_space_left;

                if(free_space_left <= MPEG_CHUNKSIZE)
                {
                    DEBUGF("0\n");
                    filling = false;
                    break;;
                }
            
                amount_to_read = MIN(MPEG_CHUNKSIZE, free_space_left);
                amount_to_read = MIN(mp3buflen - mp3buf_write, amount_to_read);
                
                /* Read in a few seconds worth of MP3 data. We don't want to
                   read too large chunks because the bitswapping will take
                   too much time. We must keep the DMA happy and also give
                   the other threads a chance to run. */
                if(mpeg_file >= 0)
                {
                    DEBUGF("R\n");
                    len = read(mpeg_file, mp3buf+mp3buf_write, amount_to_read);
                    if(len)
                    {
                        DEBUGF("B\n");
                        bitswap(mp3buf + mp3buf_write, len);
                    
                        mp3buf_write += len;
                        if(mp3buf_write >= mp3buflen)
                        {
                            mp3buf_write = 0;
                            DEBUGF("W\n");
                        }

                        /* Tell ourselves that we want more data */
                        queue_post(&mpeg_queue, MPEG_NEED_DATA, 0);

                        /* And while we're at it, see if we have started
                           playing yet. If not, do it. */
                        if(play_pending)
                        {
                            play_pending = false;
                            playing = true;
                
                            init_dma();
                            start_dma();
                        }
                    }
                    else
                    {
                        close(mpeg_file);
                        mpeg_file = -1;
                    
                        /* Make sure that the write pointer is at a word
                           boundary */
                        mp3buf_write = (mp3buf_write + 1) & 0xfffffffe;

                        if(new_file() < 0)
                        {
                            /* No more data to play */
                            DEBUGF("Finished playing\n");
                            filling = false;
                        }
                        else
                        {
                            /* Tell ourselves that we want more data */
                            queue_post(&mpeg_queue, MPEG_NEED_DATA, 0);
                        }
                    }
                }
                break;
        }
    }
}

static void setup_sci0(void)
{
    /* PB15 is I/O, PB14 is IRQ6, PB12 is SCK0 */
    PBCR1 = (PBCR1 & 0x0cff) | 0x1200;
    
    /* Set PB12 to output */
    PBIOR |= 0x1000;

    /* Disable serial port */
    SCR0 = 0x00;

    /* Synchronous, no prescale */
    SMR0 = 0x80;

    /* Set baudrate 1Mbit/s */
    BRR0 = 0x03;

    /* use SCK as serial clock output */
    SCR0 = 0x01;

    /* Clear FER and PER */
    SSR0 &= 0xe7;

    /* Set interrupt ITU2 and SCI0 priority to 0 */
    IPRD &= 0x0ff0;

    /* set IRQ6 and IRQ7 to edge detect */
    ICR |= 0x03;

    /* set PB15 and PB14 to inputs */
    PBIOR &= 0x7fff;
    PBIOR &= 0xbfff;

    /* set IRQ6 prio 8 and IRQ7 prio 0 */
    IPRB = ( IPRB & 0xff00 ) | 0x0080;

    /* Enable End of DMA interrupt at prio 8 */
    IPRC = (IPRC & 0xf0ff) | 0x0800;
    
    /* Enable Tx (only!) */
    SCR0 |= 0x20;
}


void mpeg_play(char* trackname)
{
    queue_post(&mpeg_queue, MPEG_PLAY, trackname);
}

void mpeg_stop(void)
{
    queue_post(&mpeg_queue, MPEG_STOP, NULL);
}

void mpeg_pause(void)
{
    queue_post(&mpeg_queue, MPEG_PAUSE, NULL);
}

void mpeg_resume(void)
{
    queue_post(&mpeg_queue, MPEG_RESUME, NULL);
}

void mpeg_volume(int percent)
{
    int volume = 0x38 * percent / 100;
    dac_volume(volume);
}

void mpeg_bass(int percent)
{
    int bass = 15 * percent / 100;
    mas_writereg(MAS_REG_KBASS, bass_table[bass]);
}

void mpeg_treble(int percent)
{
    int treble = 15 * percent / 100;
    mas_writereg(MAS_REG_KTREBLE, treble_table[treble]);
}

void mpeg_init(void)
{
    int rc;

    setup_sci0();
    i2c_init();

#ifdef DEBUG
    {
        unsigned char buf[32];
        unsigned char str[32];
        int i;

        rc = mas_readmem(MAS_BANK_D1,0xff6,(unsigned long*)buf,2);
        if (rc)
            panicf("Error - mas_readmem(0xff6) returned %d\n", rc);

        i = buf[0] | buf[1] << 8;
        DEBUGF("MAS version: %x\n", i);
        i = buf[4] | buf[5] << 8;
        DEBUGF("MAS revision: %x\n", i);

        rc = mas_readmem(MAS_BANK_D1,0xff9,(unsigned long*)buf,7);
        if (rc)
            panicf("Error - mas_readmem(0xff9) returned %d\n", rc);

        for (i = 0;i < 7;i++) {
            str[i*2+1] = buf[i*4];
            str[i*2] = buf[i*4+1];
        }
        str[i*2] = 0;
        DEBUGF("Description: %s\n", str);
    }
#endif

    rc = mas_writereg(0x3b, 0x20);
    if (rc < 0)
        panicf("Error - mas_writereg(0x3b) returned %d\n", rc);

    rc = mas_run(1);
    if (rc < 0)
        panicf("Error - mas_run(1) returned %d\n", rc);

    queue_init(&mpeg_queue);
    create_thread(mpeg_thread, mpeg_stack, sizeof(mpeg_stack));
    mas_poll_start(2);

    mas_writereg(MAS_REG_KPRESCALE, 0xe9400);

    mp3buflen = mp3end - mp3buf;

    if(dac_config(0x04) < 0) {
        DEBUGF("dac_config() failed\n");
    }

    mpeg_volume(70);
    mpeg_bass(50);
    mpeg_treble(50);

}