emu8000_pcm.c

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/*
 * pcm emulation on emu8000 wavetable
 *
 *  Copyright (C) 2002 Takashi Iwai <[email protected]>
 *
 *   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 program 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 General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include "emu8000_local.h"
#include <linux/init.h>
#include <linux/slab.h>
#include <sound/initval.h>
#include <sound/pcm.h>

/*
 * define the following if you want to use this pcm with non-interleaved mode
 */
/* #define USE_NONINTERLEAVE */

/* NOTE: for using the non-interleaved mode with alsa-lib, you have to set
 * mmap_emulation flag to 1 in your .asoundrc, such like
 *
 *  pcm.emu8k {
 *      type plug
 *      slave.pcm {
 *          type hw
 *          card 0
 *          device 1
 *          mmap_emulation 1
 *      }
 *  }
 *
 * besides, for the time being, the non-interleaved mode doesn't work well on
 * alsa-lib...
 */


struct snd_emu8k_pcm {
    struct snd_emu8000 *emu;
    struct snd_pcm_substream *substream;

    unsigned int allocated_bytes;
    struct snd_util_memblk *block;
    unsigned int offset;
    unsigned int buf_size;
    unsigned int period_size;
    unsigned int loop_start[2];
    unsigned int pitch;
    int panning[2];
    int last_ptr;
    int period_pos;
    int voices;
    unsigned int dram_opened: 1;
    unsigned int running: 1;
    unsigned int timer_running: 1;
    struct timer_list timer;
    spinlock_t timer_lock;
};

#define LOOP_BLANK_SIZE     8


/*
 * open up channels for the simultaneous data transfer and playback
 */
static int
emu8k_open_dram_for_pcm(struct snd_emu8000 *emu, int channels)
{
    int i;

    /* reserve up to 2 voices for playback */
    snd_emux_lock_voice(emu->emu, 0);
    if (channels > 1)
        snd_emux_lock_voice(emu->emu, 1);

    /* reserve 28 voices for loading */
    for (i = channels + 1; i < EMU8000_DRAM_VOICES; i++) {
        unsigned int mode = EMU8000_RAM_WRITE;
        snd_emux_lock_voice(emu->emu, i);
#ifndef USE_NONINTERLEAVE
        if (channels > 1 && (i & 1) != 0)
            mode |= EMU8000_RAM_RIGHT;
#endif
        snd_emu8000_dma_chan(emu, i, mode);
    }

    /* assign voice 31 and 32 to ROM */
    EMU8000_VTFT_WRITE(emu, 30, 0);
    EMU8000_PSST_WRITE(emu, 30, 0x1d8);
    EMU8000_CSL_WRITE(emu, 30, 0x1e0);
    EMU8000_CCCA_WRITE(emu, 30, 0x1d8);
    EMU8000_VTFT_WRITE(emu, 31, 0);
    EMU8000_PSST_WRITE(emu, 31, 0x1d8);
    EMU8000_CSL_WRITE(emu, 31, 0x1e0);
    EMU8000_CCCA_WRITE(emu, 31, 0x1d8);

    return 0;
}

/*
 */
static void
snd_emu8000_write_wait(struct snd_emu8000 *emu, int can_schedule)
{
    while ((EMU8000_SMALW_READ(emu) & 0x80000000) != 0) {
        if (can_schedule) {
            schedule_timeout_interruptible(1);
            if (signal_pending(current))
                break;
        }
    }
}

/*
 * close all channels
 */
static void
emu8k_close_dram(struct snd_emu8000 *emu)
{
    int i;

    for (i = 0; i < 2; i++)
        snd_emux_unlock_voice(emu->emu, i);
    for (; i < EMU8000_DRAM_VOICES; i++) {
        snd_emu8000_dma_chan(emu, i, EMU8000_RAM_CLOSE);
        snd_emux_unlock_voice(emu->emu, i);
    }
}

/*
 * convert Hz to AWE32 rate offset (see emux/soundfont.c)
 */

#define OFFSET_SAMPLERATE   1011119     /* base = 44100 */
#define SAMPLERATE_RATIO    4096

static int calc_rate_offset(int hz)
{
    return snd_sf_linear_to_log(hz, OFFSET_SAMPLERATE, SAMPLERATE_RATIO);
}


/*
 */

static struct snd_pcm_hardware emu8k_pcm_hw = {
#ifdef USE_NONINTERLEAVE
    .info =         SNDRV_PCM_INFO_NONINTERLEAVED,
#else
    .info =         SNDRV_PCM_INFO_INTERLEAVED,
#endif
    .formats =      SNDRV_PCM_FMTBIT_S16_LE,
    .rates =        SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
    .rate_min =     4000,
    .rate_max =     48000,
    .channels_min =     1,
    .channels_max =     2,
    .buffer_bytes_max = (128*1024),
    .period_bytes_min = 1024,
    .period_bytes_max = (128*1024),
    .periods_min =      2,
    .periods_max =      1024,
    .fifo_size =        0,

};

/*
 * get the current position at the given channel from CCCA register
 */
static inline int emu8k_get_curpos(struct snd_emu8k_pcm *rec, int ch)
{
    int val = EMU8000_CCCA_READ(rec->emu, ch) & 0xfffffff;
    val -= rec->loop_start[ch] - 1;
    return val;
}


/*
 * timer interrupt handler
 * check the current position and update the period if necessary.
 */
static void emu8k_pcm_timer_func(unsigned long data)
{
    struct snd_emu8k_pcm *rec = (struct snd_emu8k_pcm *)data;
    int ptr, delta;

    spin_lock(&rec->timer_lock);
    /* update the current pointer */
    ptr = emu8k_get_curpos(rec, 0);
    if (ptr < rec->last_ptr)
        delta = ptr + rec->buf_size - rec->last_ptr;
    else
        delta = ptr - rec->last_ptr;
    rec->period_pos += delta;
    rec->last_ptr = ptr;

    /* reprogram timer */
    rec->timer.expires = jiffies + 1;
    add_timer(&rec->timer);

    /* update period */
    if (rec->period_pos >= (int)rec->period_size) {
        rec->period_pos %= rec->period_size;
        spin_unlock(&rec->timer_lock);
        snd_pcm_period_elapsed(rec->substream);
        return;
    }
    spin_unlock(&rec->timer_lock);
}


/*
 * open pcm
 * creating an instance here
 */
static int emu8k_pcm_open(struct snd_pcm_substream *subs)
{
    struct snd_emu8000 *emu = snd_pcm_substream_chip(subs);
    struct snd_emu8k_pcm *rec;
    struct snd_pcm_runtime *runtime = subs->runtime;

    rec = kzalloc(sizeof(*rec), GFP_KERNEL);
    if (! rec)
        return -ENOMEM;

    rec->emu = emu;
    rec->substream = subs;
    runtime->private_data = rec;

    spin_lock_init(&rec->timer_lock);
    init_timer(&rec->timer);
    rec->timer.function = emu8k_pcm_timer_func;
    rec->timer.data = (unsigned long)rec;

    runtime->hw = emu8k_pcm_hw;
    runtime->hw.buffer_bytes_max = emu->mem_size - LOOP_BLANK_SIZE * 3;
    runtime->hw.period_bytes_max = runtime->hw.buffer_bytes_max / 2;

    /* use timer to update periods.. (specified in msec) */
    snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME,
                     (1000000 + HZ - 1) / HZ, UINT_MAX);

    return 0;
}

static int emu8k_pcm_close(struct snd_pcm_substream *subs)
{
    struct snd_emu8k_pcm *rec = subs->runtime->private_data;
    kfree(rec);
    subs->runtime->private_data = NULL;
    return 0;
}

/*
 * calculate pitch target
 */
static int calc_pitch_target(int pitch)
{
    int ptarget = 1 << (pitch >> 12);
    if (pitch & 0x800) ptarget += (ptarget * 0x102e) / 0x2710;
    if (pitch & 0x400) ptarget += (ptarget * 0x764) / 0x2710;
    if (pitch & 0x200) ptarget += (ptarget * 0x389) / 0x2710;
    ptarget += (ptarget >> 1);
    if (ptarget > 0xffff) ptarget = 0xffff;
    return ptarget;
}

/*
 * set up the voice
 */
static void setup_voice(struct snd_emu8k_pcm *rec, int ch)
{
    struct snd_emu8000 *hw = rec->emu;
    unsigned int temp;

    /* channel to be silent and idle */
    EMU8000_DCYSUSV_WRITE(hw, ch, 0x0080);
    EMU8000_VTFT_WRITE(hw, ch, 0x0000FFFF);
    EMU8000_CVCF_WRITE(hw, ch, 0x0000FFFF);
    EMU8000_PTRX_WRITE(hw, ch, 0);
    EMU8000_CPF_WRITE(hw, ch, 0);

    /* pitch offset */
    EMU8000_IP_WRITE(hw, ch, rec->pitch);
    /* set envelope parameters */
    EMU8000_ENVVAL_WRITE(hw, ch, 0x8000);
    EMU8000_ATKHLD_WRITE(hw, ch, 0x7f7f);
    EMU8000_DCYSUS_WRITE(hw, ch, 0x7f7f);
    EMU8000_ENVVOL_WRITE(hw, ch, 0x8000);
    EMU8000_ATKHLDV_WRITE(hw, ch, 0x7f7f);
    /* decay/sustain parameter for volume envelope is used
       for triggerg the voice */
    /* modulation envelope heights */
    EMU8000_PEFE_WRITE(hw, ch, 0x0);
    /* lfo1/2 delay */
    EMU8000_LFO1VAL_WRITE(hw, ch, 0x8000);
    EMU8000_LFO2VAL_WRITE(hw, ch, 0x8000);
    /* lfo1 pitch & cutoff shift */
    EMU8000_FMMOD_WRITE(hw, ch, 0);
    /* lfo1 volume & freq */
    EMU8000_TREMFRQ_WRITE(hw, ch, 0);
    /* lfo2 pitch & freq */
    EMU8000_FM2FRQ2_WRITE(hw, ch, 0);
    /* pan & loop start */
    temp = rec->panning[ch];
    temp = (temp <<24) | ((unsigned int)rec->loop_start[ch] - 1);
    EMU8000_PSST_WRITE(hw, ch, temp);
    /* chorus & loop end (chorus 8bit, MSB) */
    temp = 0; // chorus
    temp = (temp << 24) | ((unsigned int)rec->loop_start[ch] + rec->buf_size - 1);
    EMU8000_CSL_WRITE(hw, ch, temp);
    /* Q & current address (Q 4bit value, MSB) */
    temp = 0; // filterQ
    temp = (temp << 28) | ((unsigned int)rec->loop_start[ch] - 1);
    EMU8000_CCCA_WRITE(hw, ch, temp);
    /* clear unknown registers */
    EMU8000_00A0_WRITE(hw, ch, 0);
    EMU8000_0080_WRITE(hw, ch, 0);
}

/*
 * trigger the voice
 */
static void start_voice(struct snd_emu8k_pcm *rec, int ch)
{
    unsigned long flags;
    struct snd_emu8000 *hw = rec->emu;
    unsigned int temp, aux;
    int pt = calc_pitch_target(rec->pitch);

    /* cutoff and volume */
    EMU8000_IFATN_WRITE(hw, ch, 0xff00);
    EMU8000_VTFT_WRITE(hw, ch, 0xffff);
    EMU8000_CVCF_WRITE(hw, ch, 0xffff);
    /* trigger envelope */
    EMU8000_DCYSUSV_WRITE(hw, ch, 0x7f7f);
    /* set reverb and pitch target */
    temp = 0; // reverb
    if (rec->panning[ch] == 0)
        aux = 0xff;
    else
        aux = (-rec->panning[ch]) & 0xff;
    temp = (temp << 8) | (pt << 16) | aux;
    EMU8000_PTRX_WRITE(hw, ch, temp);
    EMU8000_CPF_WRITE(hw, ch, pt << 16);

    /* start timer */
    spin_lock_irqsave(&rec->timer_lock, flags);
    if (! rec->timer_running) {
        rec->timer.expires = jiffies + 1;
        add_timer(&rec->timer);
        rec->timer_running = 1;
    }
    spin_unlock_irqrestore(&rec->timer_lock, flags);
}

/*
 * stop the voice immediately
 */
static void stop_voice(struct snd_emu8k_pcm *rec, int ch)
{
    unsigned long flags;
    struct snd_emu8000 *hw = rec->emu;

    EMU8000_DCYSUSV_WRITE(hw, ch, 0x807F);

    /* stop timer */
    spin_lock_irqsave(&rec->timer_lock, flags);
    if (rec->timer_running) {
        del_timer(&rec->timer);
        rec->timer_running = 0;
    }
    spin_unlock_irqrestore(&rec->timer_lock, flags);
}

static int emu8k_pcm_trigger(struct snd_pcm_substream *subs, int cmd)
{
    struct snd_emu8k_pcm *rec = subs->runtime->private_data;
    int ch;

    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
        for (ch = 0; ch < rec->voices; ch++)
            start_voice(rec, ch);
        rec->running = 1;
        break;
    case SNDRV_PCM_TRIGGER_STOP:
        rec->running = 0;
        for (ch = 0; ch < rec->voices; ch++)
            stop_voice(rec, ch);
        break;
    default:
        return -EINVAL;
    }
    return 0;
}


/*
 * copy / silence ops
 */

/*
 * this macro should be inserted in the copy/silence loops
 * to reduce the latency.  without this, the system will hang up
 * during the whole loop.
 */
#define CHECK_SCHEDULER() \
do { \
    cond_resched();\
    if (signal_pending(current))\
        return -EAGAIN;\
} while (0)


#ifdef USE_NONINTERLEAVE
/* copy one channel block */
static int emu8k_transfer_block(struct snd_emu8000 *emu, int offset, unsigned short *buf, int count)
{
    EMU8000_SMALW_WRITE(emu, offset);
    while (count > 0) {
        unsigned short sval;
        CHECK_SCHEDULER();
        if (get_user(sval, buf))
            return -EFAULT;
        EMU8000_SMLD_WRITE(emu, sval);
        buf++;
        count--;
    }
    return 0;
}

static int emu8k_pcm_copy(struct snd_pcm_substream *subs,
              int voice,
              snd_pcm_uframes_t pos,
              void *src,
              snd_pcm_uframes_t count)
{
    struct snd_emu8k_pcm *rec = subs->runtime->private_data;
    struct snd_emu8000 *emu = rec->emu;

    snd_emu8000_write_wait(emu, 1);
    if (voice == -1) {
        unsigned short *buf = src;
        int i, err;
        count /= rec->voices;
        for (i = 0; i < rec->voices; i++) {
            err = emu8k_transfer_block(emu, pos + rec->loop_start[i], buf, count);
            if (err < 0)
                return err;
            buf += count;
        }
        return 0;
    } else {
        return emu8k_transfer_block(emu, pos + rec->loop_start[voice], src, count);
    }
}

/* make a channel block silence */
static int emu8k_silence_block(struct snd_emu8000 *emu, int offset, int count)
{
    EMU8000_SMALW_WRITE(emu, offset);
    while (count > 0) {
        CHECK_SCHEDULER();
        EMU8000_SMLD_WRITE(emu, 0);
        count--;
    }
    return 0;
}

static int emu8k_pcm_silence(struct snd_pcm_substream *subs,
                 int voice,
                 snd_pcm_uframes_t pos,
                 snd_pcm_uframes_t count)
{
    struct snd_emu8k_pcm *rec = subs->runtime->private_data;
    struct snd_emu8000 *emu = rec->emu;

    snd_emu8000_write_wait(emu, 1);
    if (voice == -1 && rec->voices == 1)
        voice = 0;
    if (voice == -1) {
        int err;
        err = emu8k_silence_block(emu, pos + rec->loop_start[0], count / 2);
        if (err < 0)
            return err;
        return emu8k_silence_block(emu, pos + rec->loop_start[1], count / 2);
    } else {
        return emu8k_silence_block(emu, pos + rec->loop_start[voice], count);
    }
}

#else /* interleave */

/*
 * copy the interleaved data can be done easily by using
 * DMA "left" and "right" channels on emu8k engine.
 */
static int emu8k_pcm_copy(struct snd_pcm_substream *subs,
              int voice,
              snd_pcm_uframes_t pos,
              void __user *src,
              snd_pcm_uframes_t count)
{
    struct snd_emu8k_pcm *rec = subs->runtime->private_data;
    struct snd_emu8000 *emu = rec->emu;
    unsigned short __user *buf = src;

    snd_emu8000_write_wait(emu, 1);
    EMU8000_SMALW_WRITE(emu, pos + rec->loop_start[0]);
    if (rec->voices > 1)
        EMU8000_SMARW_WRITE(emu, pos + rec->loop_start[1]);

    while (count-- > 0) {
        unsigned short sval;
        CHECK_SCHEDULER();
        if (get_user(sval, buf))
            return -EFAULT;
        EMU8000_SMLD_WRITE(emu, sval);
        buf++;
        if (rec->voices > 1) {
            CHECK_SCHEDULER();
            if (get_user(sval, buf))
                return -EFAULT;
            EMU8000_SMRD_WRITE(emu, sval);
            buf++;
        }
    }
    return 0;
}

static int emu8k_pcm_silence(struct snd_pcm_substream *subs,
                 int voice,
                 snd_pcm_uframes_t pos,
                 snd_pcm_uframes_t count)
{
    struct snd_emu8k_pcm *rec = subs->runtime->private_data;
    struct snd_emu8000 *emu = rec->emu;

    snd_emu8000_write_wait(emu, 1);
    EMU8000_SMALW_WRITE(emu, rec->loop_start[0] + pos);
    if (rec->voices > 1)
        EMU8000_SMARW_WRITE(emu, rec->loop_start[1] + pos);
    while (count-- > 0) {
        CHECK_SCHEDULER();
        EMU8000_SMLD_WRITE(emu, 0);
        if (rec->voices > 1) {
            CHECK_SCHEDULER();
            EMU8000_SMRD_WRITE(emu, 0);
        }
    }
    return 0;
}
#endif


/*
 * allocate a memory block
 */
static int emu8k_pcm_hw_params(struct snd_pcm_substream *subs,
                   struct snd_pcm_hw_params *hw_params)
{
    struct snd_emu8k_pcm *rec = subs->runtime->private_data;

    if (rec->block) {
        /* reallocation - release the old block */
        snd_util_mem_free(rec->emu->memhdr, rec->block);
        rec->block = NULL;
    }

    rec->allocated_bytes = params_buffer_bytes(hw_params) + LOOP_BLANK_SIZE * 4;
    rec->block = snd_util_mem_alloc(rec->emu->memhdr, rec->allocated_bytes);
    if (! rec->block)
        return -ENOMEM;
    rec->offset = EMU8000_DRAM_OFFSET + (rec->block->offset >> 1); /* in word */
    /* at least dma_bytes must be set for non-interleaved mode */
    subs->dma_buffer.bytes = params_buffer_bytes(hw_params);

    return 0;
}

/*
 * free the memory block
 */
static int emu8k_pcm_hw_free(struct snd_pcm_substream *subs)
{
    struct snd_emu8k_pcm *rec = subs->runtime->private_data;

    if (rec->block) {
        int ch;
        for (ch = 0; ch < rec->voices; ch++)
            stop_voice(rec, ch); // to be sure
        if (rec->dram_opened)
            emu8k_close_dram(rec->emu);
        snd_util_mem_free(rec->emu->memhdr, rec->block);
        rec->block = NULL;
    }
    return 0;
}

/*
 */
static int emu8k_pcm_prepare(struct snd_pcm_substream *subs)
{
    struct snd_emu8k_pcm *rec = subs->runtime->private_data;

    rec->pitch = 0xe000 + calc_rate_offset(subs->runtime->rate);
    rec->last_ptr = 0;
    rec->period_pos = 0;

    rec->buf_size = subs->runtime->buffer_size;
    rec->period_size = subs->runtime->period_size;
    rec->voices = subs->runtime->channels;
    rec->loop_start[0] = rec->offset + LOOP_BLANK_SIZE;
    if (rec->voices > 1)
        rec->loop_start[1] = rec->loop_start[0] + rec->buf_size + LOOP_BLANK_SIZE;
    if (rec->voices > 1) {
        rec->panning[0] = 0xff;
        rec->panning[1] = 0x00;
    } else
        rec->panning[0] = 0x80;

    if (! rec->dram_opened) {
        int err, i, ch;

        snd_emux_terminate_all(rec->emu->emu);
        if ((err = emu8k_open_dram_for_pcm(rec->emu, rec->voices)) != 0)
            return err;
        rec->dram_opened = 1;

        /* clear loop blanks */
        snd_emu8000_write_wait(rec->emu, 0);
        EMU8000_SMALW_WRITE(rec->emu, rec->offset);
        for (i = 0; i < LOOP_BLANK_SIZE; i++)
            EMU8000_SMLD_WRITE(rec->emu, 0);
        for (ch = 0; ch < rec->voices; ch++) {
            EMU8000_SMALW_WRITE(rec->emu, rec->loop_start[ch] + rec->buf_size);
            for (i = 0; i < LOOP_BLANK_SIZE; i++)
                EMU8000_SMLD_WRITE(rec->emu, 0);
        }
    }

    setup_voice(rec, 0);
    if (rec->voices > 1)
        setup_voice(rec, 1);
    return 0;
}

static snd_pcm_uframes_t emu8k_pcm_pointer(struct snd_pcm_substream *subs)
{
    struct snd_emu8k_pcm *rec = subs->runtime->private_data;
    if (rec->running)
        return emu8k_get_curpos(rec, 0);
    return 0;
}


static struct snd_pcm_ops emu8k_pcm_ops = {
    .open =     emu8k_pcm_open,
    .close =    emu8k_pcm_close,
    .ioctl =    snd_pcm_lib_ioctl,
    .hw_params =    emu8k_pcm_hw_params,
    .hw_free =  emu8k_pcm_hw_free,
    .prepare =  emu8k_pcm_prepare,
    .trigger =  emu8k_pcm_trigger,
    .pointer =  emu8k_pcm_pointer,
    .copy =     emu8k_pcm_copy,
    .silence =  emu8k_pcm_silence,
};


static void snd_emu8000_pcm_free(struct snd_pcm *pcm)
{
    struct snd_emu8000 *emu = pcm->private_data;
    emu->pcm = NULL;
}

int snd_emu8000_pcm_new(struct snd_card *card, struct snd_emu8000 *emu, int index)
{
    struct snd_pcm *pcm;
    int err;

    if ((err = snd_pcm_new(card, "Emu8000 PCM", index, 1, 0, &pcm)) < 0)
        return err;
    pcm->private_data = emu;
    pcm->private_free = snd_emu8000_pcm_free;
    snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &emu8k_pcm_ops);
    emu->pcm = pcm;

    snd_device_register(card, pcm);

    return 0;
}