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emu8000_pcm.c

/*
 * pcm emulation on emu8000 wavetable
 *
 *  Copyright (C) 2002 Takashi Iwai <tiwai@suse.de>
 *
 *   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();
            get_user(sval, buf);
            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();
            get_user(sval, buf);
            EMU8000_SMLD_WRITE(emu, sval);
            buf++;
            if (rec->voices > 1) {
                  CHECK_SCHEDULER();
                  get_user(sval, buf);
                  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;
}

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