/*
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 *  Routines for control of GF1 chip (PCM things)
 *
 *  InterWave chips supports interleaved DMA, but this feature isn't used in
 *  this code.
 *  
 *  This code emulates autoinit DMA transfer for playback, recording by GF1
 *  chip doesn't support autoinit DMA.
 *
 *
 *   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 <asm/dma.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/gus.h>
#include <sound/pcm_params.h>
#include "gus_tables.h"

/* maximum rate */

#define SNDRV_GF1_PCM_RATE              48000

#define SNDRV_GF1_PCM_PFLG_NONE         0
#define SNDRV_GF1_PCM_PFLG_ACTIVE       (1<<0)
#define SNDRV_GF1_PCM_PFLG_NEUTRAL      (2<<0)

struct gus_pcm_private {
        struct snd_gus_card * gus;
        struct snd_pcm_substream *substream;
        spinlock_t lock;
        unsigned int voices;
        struct snd_gus_voice *pvoices[2];
        unsigned int memory;
        unsigned short flags;
        unsigned char voice_ctrl, ramp_ctrl;
        unsigned int bpos;
        unsigned int blocks;
        unsigned int block_size;
        unsigned int dma_size;
        wait_queue_head_t sleep;
        atomic_t dma_count;
        int final_volume;
};

static int snd_gf1_pcm_use_dma = 1;

static void snd_gf1_pcm_block_change_ack(struct snd_gus_card * gus, void *private_data)
{
        struct gus_pcm_private *pcmp = private_data;

        if (pcmp) {
                atomic_dec(&pcmp->dma_count);
                wake_up(&pcmp->sleep);
        }
}

static int snd_gf1_pcm_block_change(struct snd_pcm_substream *substream,
                                    unsigned int offset,
                                    unsigned int addr,
                                    unsigned int count)
{
        struct snd_gf1_dma_block block;
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct gus_pcm_private *pcmp = runtime->private_data;

        count += offset & 31;
        offset &= ~31;
        /*
        snd_printk(KERN_DEBUG "block change - offset = 0x%x, count = 0x%x\n",
                   offset, count);
        */
        memset(&block, 0, sizeof(block));
        block.cmd = SNDRV_GF1_DMA_IRQ;
        if (snd_pcm_format_unsigned(runtime->format))
                block.cmd |= SNDRV_GF1_DMA_UNSIGNED;
        if (snd_pcm_format_width(runtime->format) == 16)
                block.cmd |= SNDRV_GF1_DMA_16BIT;
        block.addr = addr & ~31;
        block.buffer = runtime->dma_area + offset;
        block.buf_addr = runtime->dma_addr + offset;
        block.count = count;
        block.private_data = pcmp;
        block.ack = snd_gf1_pcm_block_change_ack;
        if (!snd_gf1_dma_transfer_block(pcmp->gus, &block, 0, 0))
                atomic_inc(&pcmp->dma_count);
        return 0;
}

static void snd_gf1_pcm_trigger_up(struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct gus_pcm_private *pcmp = runtime->private_data;
        struct snd_gus_card * gus = pcmp->gus;
        unsigned long flags;
        unsigned char voice_ctrl, ramp_ctrl;
        unsigned short rate;
        unsigned int curr, begin, end;
        unsigned short vol;
        unsigned char pan;
        unsigned int voice;

        spin_lock_irqsave(&pcmp->lock, flags);
        if (pcmp->flags & SNDRV_GF1_PCM_PFLG_ACTIVE) {
                spin_unlock_irqrestore(&pcmp->lock, flags);
                return;
        }
        pcmp->flags |= SNDRV_GF1_PCM_PFLG_ACTIVE;
        pcmp->final_volume = 0;
        spin_unlock_irqrestore(&pcmp->lock, flags);
        rate = snd_gf1_translate_freq(gus, runtime->rate << 4);
        /* enable WAVE IRQ */
        voice_ctrl = snd_pcm_format_width(runtime->format) == 16 ? 0x24 : 0x20;
        /* enable RAMP IRQ + rollover */
        ramp_ctrl = 0x24;
        if (pcmp->blocks == 1) {
                voice_ctrl |= 0x08;     /* loop enable */
                ramp_ctrl &= ~0x04;     /* disable rollover */
        }
        for (voice = 0; voice < pcmp->voices; voice++) {
                begin = pcmp->memory + voice * (pcmp->dma_size / runtime->channels);
                curr = begin + (pcmp->bpos * pcmp->block_size) / runtime->channels;
                end = curr + (pcmp->block_size / runtime->channels);
                end -= snd_pcm_format_width(runtime->format) == 16 ? 2 : 1;
                /*
                snd_printk(KERN_DEBUG "init: curr=0x%x, begin=0x%x, end=0x%x, "
                           "ctrl=0x%x, ramp=0x%x, rate=0x%x\n",
                           curr, begin, end, voice_ctrl, ramp_ctrl, rate);
                */
                pan = runtime->channels == 2 ? (!voice ? 1 : 14) : 8;
                vol = !voice ? gus->gf1.pcm_volume_level_left : gus->gf1.pcm_volume_level_right;
                spin_lock_irqsave(&gus->reg_lock, flags);
                snd_gf1_select_voice(gus, pcmp->pvoices[voice]->number);
                snd_gf1_write8(gus, SNDRV_GF1_VB_PAN, pan);
                snd_gf1_write16(gus, SNDRV_GF1_VW_FREQUENCY, rate);
                snd_gf1_write_addr(gus, SNDRV_GF1_VA_START, begin << 4, voice_ctrl & 4);
                snd_gf1_write_addr(gus, SNDRV_GF1_VA_END, end << 4, voice_ctrl & 4);
                snd_gf1_write_addr(gus, SNDRV_GF1_VA_CURRENT, curr << 4, voice_ctrl & 4);
                snd_gf1_write16(gus, SNDRV_GF1_VW_VOLUME, SNDRV_GF1_MIN_VOLUME << 4);
                snd_gf1_write8(gus, SNDRV_GF1_VB_VOLUME_RATE, 0x2f);
                snd_gf1_write8(gus, SNDRV_GF1_VB_VOLUME_START, SNDRV_GF1_MIN_OFFSET);
                snd_gf1_write8(gus, SNDRV_GF1_VB_VOLUME_END, vol >> 8);
                snd_gf1_write8(gus, SNDRV_GF1_VB_VOLUME_CONTROL, ramp_ctrl);
                if (!gus->gf1.enh_mode) {
                        snd_gf1_delay(gus);
                        snd_gf1_write8(gus, SNDRV_GF1_VB_VOLUME_CONTROL, ramp_ctrl);
                }
                spin_unlock_irqrestore(&gus->reg_lock, flags);
        }
        spin_lock_irqsave(&gus->reg_lock, flags);
        for (voice = 0; voice < pcmp->voices; voice++) {
                snd_gf1_select_voice(gus, pcmp->pvoices[voice]->number);
                if (gus->gf1.enh_mode)
                        snd_gf1_write8(gus, SNDRV_GF1_VB_MODE, 0x00);   /* deactivate voice */
                snd_gf1_write8(gus, SNDRV_GF1_VB_ADDRESS_CONTROL, voice_ctrl);
                voice_ctrl &= ~0x20;
        }
        voice_ctrl |= 0x20;
        if (!gus->gf1.enh_mode) {
                snd_gf1_delay(gus);
                for (voice = 0; voice < pcmp->voices; voice++) {
                        snd_gf1_select_voice(gus, pcmp->pvoices[voice]->number);
                        snd_gf1_write8(gus, SNDRV_GF1_VB_ADDRESS_CONTROL, voice_ctrl);
                        voice_ctrl &= ~0x20;    /* disable IRQ for next voice */
                }
        }
        spin_unlock_irqrestore(&gus->reg_lock, flags);
}

static void snd_gf1_pcm_interrupt_wave(struct snd_gus_card * gus,
                                       struct snd_gus_voice *pvoice)
{
        struct gus_pcm_private * pcmp;
        struct snd_pcm_runtime *runtime;
        unsigned char voice_ctrl, ramp_ctrl;
        unsigned int idx;
        unsigned int end, step;

        if (!pvoice->private_data) {
                snd_printd("snd_gf1_pcm: unknown wave irq?\n");
                snd_gf1_smart_stop_voice(gus, pvoice->number);
                return;
        }
        pcmp = pvoice->private_data;
        if (pcmp == NULL) {
                snd_printd("snd_gf1_pcm: unknown wave irq?\n");
                snd_gf1_smart_stop_voice(gus, pvoice->number);
                return;
        }               
        gus = pcmp->gus;
        runtime = pcmp->substream->runtime;

        spin_lock(&gus->reg_lock);
        snd_gf1_select_voice(gus, pvoice->number);
        voice_ctrl = snd_gf1_read8(gus, SNDRV_GF1_VB_ADDRESS_CONTROL) & ~0x8b;
        ramp_ctrl = (snd_gf1_read8(gus, SNDRV_GF1_VB_VOLUME_CONTROL) & ~0xa4) | 0x03;
#if 0
        snd_gf1_select_voice(gus, pvoice->number);
        printk(KERN_DEBUG "position = 0x%x\n",
               (snd_gf1_read_addr(gus, SNDRV_GF1_VA_CURRENT, voice_ctrl & 4) >> 4));
        snd_gf1_select_voice(gus, pcmp->pvoices[1]->number);
        printk(KERN_DEBUG "position = 0x%x\n",
               (snd_gf1_read_addr(gus, SNDRV_GF1_VA_CURRENT, voice_ctrl & 4) >> 4));
        snd_gf1_select_voice(gus, pvoice->number);
#endif
        pcmp->bpos++;
        pcmp->bpos %= pcmp->blocks;
        if (pcmp->bpos + 1 >= pcmp->blocks) {   /* last block? */
                voice_ctrl |= 0x08;     /* enable loop */
        } else {
                ramp_ctrl |= 0x04;      /* enable rollover */
        }
        end = pcmp->memory + (((pcmp->bpos + 1) * pcmp->block_size) / runtime->channels);
        end -= voice_ctrl & 4 ? 2 : 1;
        step = pcmp->dma_size / runtime->channels;
        voice_ctrl |= 0x20;
        if (!pcmp->final_volume) {
                ramp_ctrl |= 0x20;
                ramp_ctrl &= ~0x03;
        }
        for (idx = 0; idx < pcmp->voices; idx++, end += step) {
                snd_gf1_select_voice(gus, pcmp->pvoices[idx]->number);
                snd_gf1_write_addr(gus, SNDRV_GF1_VA_END, end << 4, voice_ctrl & 4);
                snd_gf1_write8(gus, SNDRV_GF1_VB_ADDRESS_CONTROL, voice_ctrl);
                snd_gf1_write8(gus, SNDRV_GF1_VB_VOLUME_CONTROL, ramp_ctrl);
                voice_ctrl &= ~0x20;
        }
        if (!gus->gf1.enh_mode) {
                snd_gf1_delay(gus);
                voice_ctrl |= 0x20;
                for (idx = 0; idx < pcmp->voices; idx++) {
                        snd_gf1_select_voice(gus, pcmp->pvoices[idx]->number);
                        snd_gf1_write8(gus, SNDRV_GF1_VB_ADDRESS_CONTROL, voice_ctrl);
                        snd_gf1_write8(gus, SNDRV_GF1_VB_VOLUME_CONTROL, ramp_ctrl);
                        voice_ctrl &= ~0x20;
                }
        }
        spin_unlock(&gus->reg_lock);

        snd_pcm_period_elapsed(pcmp->substream);
#if 0
        if ((runtime->flags & SNDRV_PCM_FLG_MMAP) &&
            *runtime->state == SNDRV_PCM_STATE_RUNNING) {
                end = pcmp->bpos * pcmp->block_size;
                if (runtime->channels > 1) {
                        snd_gf1_pcm_block_change(pcmp->substream, end, pcmp->memory + (end / 2), pcmp->block_size / 2);
                        snd_gf1_pcm_block_change(pcmp->substream, end + (pcmp->block_size / 2), pcmp->memory + (pcmp->dma_size / 2) + (end / 2), pcmp->block_size / 2);
                } else {
                        snd_gf1_pcm_block_change(pcmp->substream, end, pcmp->memory + end, pcmp->block_size);
                }
        }
#endif
}

static void snd_gf1_pcm_interrupt_volume(struct snd_gus_card * gus,
                                         struct snd_gus_voice * pvoice)
{
        unsigned short vol;
        int cvoice;
        struct gus_pcm_private *pcmp = pvoice->private_data;

        /* stop ramp, but leave rollover bit untouched */
        spin_lock(&gus->reg_lock);
        snd_gf1_select_voice(gus, pvoice->number);
        snd_gf1_ctrl_stop(gus, SNDRV_GF1_VB_VOLUME_CONTROL);
        spin_unlock(&gus->reg_lock);
        if (pcmp == NULL)
                return;
        /* are we active? */
        if (!(pcmp->flags & SNDRV_GF1_PCM_PFLG_ACTIVE))
                return;
        /* load real volume - better precision */
        cvoice = pcmp->pvoices[0] == pvoice ? 0 : 1;
        if (pcmp->substream == NULL)
                return;
        vol = !cvoice ? gus->gf1.pcm_volume_level_left : gus->gf1.pcm_volume_level_right;
        spin_lock(&gus->reg_lock);
        snd_gf1_select_voice(gus, pvoice->number);
        snd_gf1_write16(gus, SNDRV_GF1_VW_VOLUME, vol);
        pcmp->final_volume = 1;
        spin_unlock(&gus->reg_lock);
}

static void snd_gf1_pcm_volume_change(struct snd_gus_card * gus)
{
}

static int snd_gf1_pcm_poke_block(struct snd_gus_card *gus, unsigned char *buf,
                                  unsigned int pos, unsigned int count,
                                  int w16, int invert)
{
        unsigned int len;
        unsigned long flags;

        /*
        printk(KERN_DEBUG
               "poke block; buf = 0x%x, pos = %i, count = %i, port = 0x%x\n",
               (int)buf, pos, count, gus->gf1.port);
        */
        while (count > 0) {
                len = count;
                if (len > 512)          /* limit, to allow IRQ */
                        len = 512;
                count -= len;
                if (gus->interwave) {
                        spin_lock_irqsave(&gus->reg_lock, flags);
                        snd_gf1_write8(gus, SNDRV_GF1_GB_MEMORY_CONTROL, 0x01 | (invert ? 0x08 : 0x00));
                        snd_gf1_dram_addr(gus, pos);
                        if (w16) {
                                outb(SNDRV_GF1_GW_DRAM_IO16, GUSP(gus, GF1REGSEL));
                                outsw(GUSP(gus, GF1DATALOW), buf, len >> 1);
                        } else {
                                outsb(GUSP(gus, DRAM), buf, len);
                        }
                        spin_unlock_irqrestore(&gus->reg_lock, flags);
                        buf += 512;
                        pos += 512;
                } else {
                        invert = invert ? 0x80 : 0x00;
                        if (w16) {
                                len >>= 1;
                                while (len--) {
                                        snd_gf1_poke(gus, pos++, *buf++);
                                        snd_gf1_poke(gus, pos++, *buf++ ^ invert);
                                }
                        } else {
                                while (len--)
                                        snd_gf1_poke(gus, pos++, *buf++ ^ invert);
                        }
                }
                if (count > 0 && !in_interrupt()) {
                        schedule_timeout_interruptible(1);
                        if (signal_pending(current))
                                return -EAGAIN;
                }
        }
        return 0;
}

static int snd_gf1_pcm_playback_copy(struct snd_pcm_substream *substream,
                                     int voice,
                                     snd_pcm_uframes_t pos,
                                     void __user *src,
                                     snd_pcm_uframes_t count)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct gus_pcm_private *pcmp = runtime->private_data;
        unsigned int bpos, len;
        
        bpos = samples_to_bytes(runtime, pos) + (voice * (pcmp->dma_size / 2));
        len = samples_to_bytes(runtime, count);
        if (snd_BUG_ON(bpos > pcmp->dma_size))
                return -EIO;
        if (snd_BUG_ON(bpos + len > pcmp->dma_size))
                return -EIO;
        if (copy_from_user(runtime->dma_area + bpos, src, len))
                return -EFAULT;
        if (snd_gf1_pcm_use_dma && len > 32) {
                return snd_gf1_pcm_block_change(substream, bpos, pcmp->memory + bpos, len);
        } else {
                struct snd_gus_card *gus = pcmp->gus;
                int err, w16, invert;

                w16 = (snd_pcm_format_width(runtime->format) == 16);
                invert = snd_pcm_format_unsigned(runtime->format);
                if ((err = snd_gf1_pcm_poke_block(gus, runtime->dma_area + bpos, pcmp->memory + bpos, len, w16, invert)) < 0)
                        return err;
        }
        return 0;
}

static int snd_gf1_pcm_playback_silence(struct snd_pcm_substream *substream,
                                        int voice,
                                        snd_pcm_uframes_t pos,
                                        snd_pcm_uframes_t count)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct gus_pcm_private *pcmp = runtime->private_data;
        unsigned int bpos, len;
        
        bpos = samples_to_bytes(runtime, pos) + (voice * (pcmp->dma_size / 2));
        len = samples_to_bytes(runtime, count);
        if (snd_BUG_ON(bpos > pcmp->dma_size))
                return -EIO;
        if (snd_BUG_ON(bpos + len > pcmp->dma_size))
                return -EIO;
        snd_pcm_format_set_silence(runtime->format, runtime->dma_area + bpos, count);
        if (snd_gf1_pcm_use_dma && len > 32) {
                return snd_gf1_pcm_block_change(substream, bpos, pcmp->memory + bpos, len);
        } else {
                struct snd_gus_card *gus = pcmp->gus;
                int err, w16, invert;

                w16 = (snd_pcm_format_width(runtime->format) == 16);
                invert = snd_pcm_format_unsigned(runtime->format);
                if ((err = snd_gf1_pcm_poke_block(gus, runtime->dma_area + bpos, pcmp->memory + bpos, len, w16, invert)) < 0)
                        return err;
        }
        return 0;
}

static int snd_gf1_pcm_playback_hw_params(struct snd_pcm_substream *substream,
                                          struct snd_pcm_hw_params *hw_params)
{
        struct snd_gus_card *gus = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct gus_pcm_private *pcmp = runtime->private_data;
        int err;
        
        if ((err = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params))) < 0)
                return err;
        if (err > 0) {  /* change */
                struct snd_gf1_mem_block *block;
                if (pcmp->memory > 0) {
                        snd_gf1_mem_free(&gus->gf1.mem_alloc, pcmp->memory);
                        pcmp->memory = 0;
                }
                if ((block = snd_gf1_mem_alloc(&gus->gf1.mem_alloc,
                                               SNDRV_GF1_MEM_OWNER_DRIVER,
                                               "GF1 PCM",
                                               runtime->dma_bytes, 1, 32,
                                               NULL)) == NULL)
                        return -ENOMEM;
                pcmp->memory = block->ptr;
        }
        pcmp->voices = params_channels(hw_params);
        if (pcmp->pvoices[0] == NULL) {
                if ((pcmp->pvoices[0] = snd_gf1_alloc_voice(pcmp->gus, SNDRV_GF1_VOICE_TYPE_PCM, 0, 0)) == NULL)
                        return -ENOMEM;
                pcmp->pvoices[0]->handler_wave = snd_gf1_pcm_interrupt_wave;
                pcmp->pvoices[0]->handler_volume = snd_gf1_pcm_interrupt_volume;
                pcmp->pvoices[0]->volume_change = snd_gf1_pcm_volume_change;
                pcmp->pvoices[0]->private_data = pcmp;
        }
        if (pcmp->voices > 1 && pcmp->pvoices[1] == NULL) {
                if ((pcmp->pvoices[1] = snd_gf1_alloc_voice(pcmp->gus, SNDRV_GF1_VOICE_TYPE_PCM, 0, 0)) == NULL)
                        return -ENOMEM;
                pcmp->pvoices[1]->handler_wave = snd_gf1_pcm_interrupt_wave;
                pcmp->pvoices[1]->handler_volume = snd_gf1_pcm_interrupt_volume;
                pcmp->pvoices[1]->volume_change = snd_gf1_pcm_volume_change;
                pcmp->pvoices[1]->private_data = pcmp;
        } else if (pcmp->voices == 1) {
                if (pcmp->pvoices[1]) {
                        snd_gf1_free_voice(pcmp->gus, pcmp->pvoices[1]);
                        pcmp->pvoices[1] = NULL;
                }
        }
        return 0;
}

static int snd_gf1_pcm_playback_hw_free(struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct gus_pcm_private *pcmp = runtime->private_data;

        snd_pcm_lib_free_pages(substream);
        if (pcmp->pvoices[0]) {
                snd_gf1_free_voice(pcmp->gus, pcmp->pvoices[0]);
                pcmp->pvoices[0] = NULL;
        }
        if (pcmp->pvoices[1]) {
                snd_gf1_free_voice(pcmp->gus, pcmp->pvoices[1]);
                pcmp->pvoices[1] = NULL;
        }
        if (pcmp->memory > 0) {
                snd_gf1_mem_free(&pcmp->gus->gf1.mem_alloc, pcmp->memory);
                pcmp->memory = 0;
        }
        return 0;
}

static int snd_gf1_pcm_playback_prepare(struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct gus_pcm_private *pcmp = runtime->private_data;

        pcmp->bpos = 0;
        pcmp->dma_size = snd_pcm_lib_buffer_bytes(substream);
        pcmp->block_size = snd_pcm_lib_period_bytes(substream);
        pcmp->blocks = pcmp->dma_size / pcmp->block_size;
        return 0;
}

static int snd_gf1_pcm_playback_trigger(struct snd_pcm_substream *substream,
                                        int cmd)
{
        struct snd_gus_card *gus = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct gus_pcm_private *pcmp = runtime->private_data;
        int voice;

        if (cmd == SNDRV_PCM_TRIGGER_START) {
                snd_gf1_pcm_trigger_up(substream);
        } else if (cmd == SNDRV_PCM_TRIGGER_STOP) {
                spin_lock(&pcmp->lock);
                pcmp->flags &= ~SNDRV_GF1_PCM_PFLG_ACTIVE;
                spin_unlock(&pcmp->lock);
                voice = pcmp->pvoices[0]->number;
                snd_gf1_stop_voices(gus, voice, voice);
                if (pcmp->pvoices[1]) {
                        voice = pcmp->pvoices[1]->number;
                        snd_gf1_stop_voices(gus, voice, voice);
                }
        } else {
                return -EINVAL;
        }
        return 0;
}

static snd_pcm_uframes_t snd_gf1_pcm_playback_pointer(struct snd_pcm_substream *substream)
{
        struct snd_gus_card *gus = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct gus_pcm_private *pcmp = runtime->private_data;
        unsigned int pos;
        unsigned char voice_ctrl;

        pos = 0;
        spin_lock(&gus->reg_lock);
        if (pcmp->flags & SNDRV_GF1_PCM_PFLG_ACTIVE) {
                snd_gf1_select_voice(gus, pcmp->pvoices[0]->number);
                voice_ctrl = snd_gf1_read8(gus, SNDRV_GF1_VB_ADDRESS_CONTROL);
                pos = (snd_gf1_read_addr(gus, SNDRV_GF1_VA_CURRENT, voice_ctrl & 4) >> 4) - pcmp->memory;
                if (substream->runtime->channels > 1)
                        pos <<= 1;
                pos = bytes_to_frames(runtime, pos);
        }
        spin_unlock(&gus->reg_lock);
        return pos;
}

static struct snd_ratnum clock = {
        .num = 9878400/16,
        .den_min = 2,
        .den_max = 257,
        .den_step = 1,
};

static struct snd_pcm_hw_constraint_ratnums hw_constraints_clocks  = {
        .nrats = 1,
        .rats = &clock,
};

static int snd_gf1_pcm_capture_hw_params(struct snd_pcm_substream *substream,
                                         struct snd_pcm_hw_params *hw_params)
{
        struct snd_gus_card *gus = snd_pcm_substream_chip(substream);

        gus->c_dma_size = params_buffer_bytes(hw_params);
        gus->c_period_size = params_period_bytes(hw_params);
        gus->c_pos = 0;
        gus->gf1.pcm_rcntrl_reg = 0x21;         /* IRQ at end, enable & start */
        if (params_channels(hw_params) > 1)
                gus->gf1.pcm_rcntrl_reg |= 2;
        if (gus->gf1.dma2 > 3)
                gus->gf1.pcm_rcntrl_reg |= 4;
        if (snd_pcm_format_unsigned(params_format(hw_params)))
                gus->gf1.pcm_rcntrl_reg |= 0x80;
        return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
}

static int snd_gf1_pcm_capture_hw_free(struct snd_pcm_substream *substream)
{
        return snd_pcm_lib_free_pages(substream);
}

static int snd_gf1_pcm_capture_prepare(struct snd_pcm_substream *substream)
{
        struct snd_gus_card *gus = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;

        snd_gf1_i_write8(gus, SNDRV_GF1_GB_RECORD_RATE, runtime->rate_den - 2);
        snd_gf1_i_write8(gus, SNDRV_GF1_GB_REC_DMA_CONTROL, 0); /* disable sampling */
        snd_gf1_i_look8(gus, SNDRV_GF1_GB_REC_DMA_CONTROL);     /* Sampling Control Register */
        snd_dma_program(gus->gf1.dma2, runtime->dma_addr, gus->c_period_size, DMA_MODE_READ);
        return 0;
}

static int snd_gf1_pcm_capture_trigger(struct snd_pcm_substream *substream,
                                       int cmd)
{
        struct snd_gus_card *gus = snd_pcm_substream_chip(substream);
        int val;
        
        if (cmd == SNDRV_PCM_TRIGGER_START) {
                val = gus->gf1.pcm_rcntrl_reg;
        } else if (cmd == SNDRV_PCM_TRIGGER_STOP) {
                val = 0;
        } else {
                return -EINVAL;
        }

        spin_lock(&gus->reg_lock);
        snd_gf1_write8(gus, SNDRV_GF1_GB_REC_DMA_CONTROL, val);
        snd_gf1_look8(gus, SNDRV_GF1_GB_REC_DMA_CONTROL);
        spin_unlock(&gus->reg_lock);
        return 0;
}

static snd_pcm_uframes_t snd_gf1_pcm_capture_pointer(struct snd_pcm_substream *substream)
{
        struct snd_gus_card *gus = snd_pcm_substream_chip(substream);
        int pos = snd_dma_pointer(gus->gf1.dma2, gus->c_period_size);
        pos = bytes_to_frames(substream->runtime, (gus->c_pos + pos) % gus->c_dma_size);
        return pos;
}

static void snd_gf1_pcm_interrupt_dma_read(struct snd_gus_card * gus)
{
        snd_gf1_i_write8(gus, SNDRV_GF1_GB_REC_DMA_CONTROL, 0); /* disable sampling */
        snd_gf1_i_look8(gus, SNDRV_GF1_GB_REC_DMA_CONTROL);     /* Sampling Control Register */
        if (gus->pcm_cap_substream != NULL) {
                snd_gf1_pcm_capture_prepare(gus->pcm_cap_substream); 
                snd_gf1_pcm_capture_trigger(gus->pcm_cap_substream, SNDRV_PCM_TRIGGER_START);
                gus->c_pos += gus->c_period_size;
                snd_pcm_period_elapsed(gus->pcm_cap_substream);
        }
}

static struct snd_pcm_hardware snd_gf1_pcm_playback =
{
        .info =                 SNDRV_PCM_INFO_NONINTERLEAVED,
        .formats                = (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_U8 |
                                 SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_U16_LE),
        .rates =                SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
        .rate_min =             5510,
        .rate_max =             48000,
        .channels_min =         1,
        .channels_max =         2,
        .buffer_bytes_max =     (128*1024),
        .period_bytes_min =     64,
        .period_bytes_max =     (128*1024),
        .periods_min =          1,
        .periods_max =          1024,
        .fifo_size =            0,
};

static struct snd_pcm_hardware snd_gf1_pcm_capture =
{
        .info =                 (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
                                 SNDRV_PCM_INFO_MMAP_VALID),
        .formats =              SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_U8,
        .rates =                SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_44100,
        .rate_min =             5510,
        .rate_max =             44100,
        .channels_min =         1,
        .channels_max =         2,
        .buffer_bytes_max =     (128*1024),
        .period_bytes_min =     64,
        .period_bytes_max =     (128*1024),
        .periods_min =          1,
        .periods_max =          1024,
        .fifo_size =            0,
};

static void snd_gf1_pcm_playback_free(struct snd_pcm_runtime *runtime)
{
        kfree(runtime->private_data);
}

static int snd_gf1_pcm_playback_open(struct snd_pcm_substream *substream)
{
        struct gus_pcm_private *pcmp;
        struct snd_gus_card *gus = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        int err;

        pcmp = kzalloc(sizeof(*pcmp), GFP_KERNEL);
        if (pcmp == NULL)
                return -ENOMEM;
        pcmp->gus = gus;
        spin_lock_init(&pcmp->lock);
        init_waitqueue_head(&pcmp->sleep);
        atomic_set(&pcmp->dma_count, 0);

        runtime->private_data = pcmp;
        runtime->private_free = snd_gf1_pcm_playback_free;

#if 0
        printk(KERN_DEBUG "playback.buffer = 0x%lx, gf1.pcm_buffer = 0x%lx\n",
               (long) pcm->playback.buffer, (long) gus->gf1.pcm_buffer);
#endif
        if ((err = snd_gf1_dma_init(gus)) < 0)
                return err;
        pcmp->flags = SNDRV_GF1_PCM_PFLG_NONE;
        pcmp->substream = substream;
        runtime->hw = snd_gf1_pcm_playback;
        snd_pcm_limit_isa_dma_size(gus->gf1.dma1, &runtime->hw.buffer_bytes_max);
        snd_pcm_limit_isa_dma_size(gus->gf1.dma1, &runtime->hw.period_bytes_max);
        snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 64);
        return 0;
}

static int snd_gf1_pcm_playback_close(struct snd_pcm_substream *substream)
{
        struct snd_gus_card *gus = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct gus_pcm_private *pcmp = runtime->private_data;
        
        if (!wait_event_timeout(pcmp->sleep, (atomic_read(&pcmp->dma_count) <= 0), 2*HZ))
                snd_printk(KERN_ERR "gf1 pcm - serious DMA problem\n");

        snd_gf1_dma_done(gus);  
        return 0;
}

static int snd_gf1_pcm_capture_open(struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_gus_card *gus = snd_pcm_substream_chip(substream);

        gus->gf1.interrupt_handler_dma_read = snd_gf1_pcm_interrupt_dma_read;
        gus->pcm_cap_substream = substream;
        substream->runtime->hw = snd_gf1_pcm_capture;
        snd_pcm_limit_isa_dma_size(gus->gf1.dma2, &runtime->hw.buffer_bytes_max);
        snd_pcm_limit_isa_dma_size(gus->gf1.dma2, &runtime->hw.period_bytes_max);
        snd_pcm_hw_constraint_ratnums(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
                                      &hw_constraints_clocks);
        return 0;
}

static int snd_gf1_pcm_capture_close(struct snd_pcm_substream *substream)
{
        struct snd_gus_card *gus = snd_pcm_substream_chip(substream);

        gus->pcm_cap_substream = NULL;
        snd_gf1_set_default_handlers(gus, SNDRV_GF1_HANDLER_DMA_READ);
        return 0;
}

static int snd_gf1_pcm_volume_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
{
        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
        uinfo->count = 2;
        uinfo->value.integer.min = 0;
        uinfo->value.integer.max = 127;
        return 0;
}

static int snd_gf1_pcm_volume_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
{
        struct snd_gus_card *gus = snd_kcontrol_chip(kcontrol);
        unsigned long flags;
        
        spin_lock_irqsave(&gus->pcm_volume_level_lock, flags);
        ucontrol->value.integer.value[0] = gus->gf1.pcm_volume_level_left1;
        ucontrol->value.integer.value[1] = gus->gf1.pcm_volume_level_right1;
        spin_unlock_irqrestore(&gus->pcm_volume_level_lock, flags);
        return 0;
}

static int snd_gf1_pcm_volume_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
{
        struct snd_gus_card *gus = snd_kcontrol_chip(kcontrol);
        unsigned long flags;
        int change;
        unsigned int idx;
        unsigned short val1, val2, vol;
        struct gus_pcm_private *pcmp;
        struct snd_gus_voice *pvoice;
        
        val1 = ucontrol->value.integer.value[0] & 127;
        val2 = ucontrol->value.integer.value[1] & 127;
        spin_lock_irqsave(&gus->pcm_volume_level_lock, flags);
        change = val1 != gus->gf1.pcm_volume_level_left1 ||
                 val2 != gus->gf1.pcm_volume_level_right1;
        gus->gf1.pcm_volume_level_left1 = val1;
        gus->gf1.pcm_volume_level_right1 = val2;
        gus->gf1.pcm_volume_level_left = snd_gf1_lvol_to_gvol_raw(val1 << 9) << 4;
        gus->gf1.pcm_volume_level_right = snd_gf1_lvol_to_gvol_raw(val2 << 9) << 4;
        spin_unlock_irqrestore(&gus->pcm_volume_level_lock, flags);
        /* are we active? */
        spin_lock_irqsave(&gus->voice_alloc, flags);
        for (idx = 0; idx < 32; idx++) {
                pvoice = &gus->gf1.voices[idx];
                if (!pvoice->pcm)
                        continue;
                pcmp = pvoice->private_data;
                if (!(pcmp->flags & SNDRV_GF1_PCM_PFLG_ACTIVE))
                        continue;
                /* load real volume - better precision */
                spin_lock(&gus->reg_lock);
                snd_gf1_select_voice(gus, pvoice->number);
                snd_gf1_ctrl_stop(gus, SNDRV_GF1_VB_VOLUME_CONTROL);
                vol = pvoice == pcmp->pvoices[0] ? gus->gf1.pcm_volume_level_left : gus->gf1.pcm_volume_level_right;
                snd_gf1_write16(gus, SNDRV_GF1_VW_VOLUME, vol);
                pcmp->final_volume = 1;
                spin_unlock(&gus->reg_lock);
        }
        spin_unlock_irqrestore(&gus->voice_alloc, flags);
        return change;
}

static struct snd_kcontrol_new snd_gf1_pcm_volume_control =
{
        .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
        .name = "PCM Playback Volume",
        .info = snd_gf1_pcm_volume_info,
        .get = snd_gf1_pcm_volume_get,
        .put = snd_gf1_pcm_volume_put
};

static struct snd_kcontrol_new snd_gf1_pcm_volume_control1 =
{
        .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
        .name = "GPCM Playback Volume",
        .info = snd_gf1_pcm_volume_info,
        .get = snd_gf1_pcm_volume_get,
        .put = snd_gf1_pcm_volume_put
};

static struct snd_pcm_ops snd_gf1_pcm_playback_ops = {
        .open =         snd_gf1_pcm_playback_open,
        .close =        snd_gf1_pcm_playback_close,
        .ioctl =        snd_pcm_lib_ioctl,
        .hw_params =    snd_gf1_pcm_playback_hw_params,
        .hw_free =      snd_gf1_pcm_playback_hw_free,
        .prepare =      snd_gf1_pcm_playback_prepare,
        .trigger =      snd_gf1_pcm_playback_trigger,
        .pointer =      snd_gf1_pcm_playback_pointer,
        .copy =         snd_gf1_pcm_playback_copy,
        .silence =      snd_gf1_pcm_playback_silence,
};

static struct snd_pcm_ops snd_gf1_pcm_capture_ops = {
        .open =         snd_gf1_pcm_capture_open,
        .close =        snd_gf1_pcm_capture_close,
        .ioctl =        snd_pcm_lib_ioctl,
        .hw_params =    snd_gf1_pcm_capture_hw_params,
        .hw_free =      snd_gf1_pcm_capture_hw_free,
        .prepare =      snd_gf1_pcm_capture_prepare,
        .trigger =      snd_gf1_pcm_capture_trigger,
        .pointer =      snd_gf1_pcm_capture_pointer,
};

int snd_gf1_pcm_new(struct snd_gus_card * gus, int pcm_dev, int control_index, struct snd_pcm ** rpcm)
{
        struct snd_card *card;
        struct snd_kcontrol *kctl;
        struct snd_pcm *pcm;
        struct snd_pcm_substream *substream;
        int capture, err;

        if (rpcm)
                *rpcm = NULL;
        card = gus->card;
        capture = !gus->interwave && !gus->ess_flag && !gus->ace_flag ? 1 : 0;
        err = snd_pcm_new(card,
                          gus->interwave ? "AMD InterWave" : "GF1",
                          pcm_dev,
                          gus->gf1.pcm_channels / 2,
                          capture,
                          &pcm);
        if (err < 0)
                return err;
        pcm->private_data = gus;
        /* playback setup */
        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_gf1_pcm_playback_ops);

        for (substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream; substream; substream = substream->next)
                snd_pcm_lib_preallocate_pages(substream, SNDRV_DMA_TYPE_DEV,
                                              snd_dma_isa_data(),
                                              64*1024, gus->gf1.dma1 > 3 ? 128*1024 : 64*1024);
        
        pcm->info_flags = 0;
        pcm->dev_subclass = SNDRV_PCM_SUBCLASS_GENERIC_MIX;
        if (capture) {
                snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_gf1_pcm_capture_ops);
                if (gus->gf1.dma2 == gus->gf1.dma1)
                        pcm->info_flags |= SNDRV_PCM_INFO_HALF_DUPLEX;
                snd_pcm_lib_preallocate_pages(pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream,
                                              SNDRV_DMA_TYPE_DEV, snd_dma_isa_data(),
                                              64*1024, gus->gf1.dma2 > 3 ? 128*1024 : 64*1024);
        }
        strcpy(pcm->name, pcm->id);
        if (gus->interwave) {
                sprintf(pcm->name + strlen(pcm->name), " rev %c", gus->revision + 'A');
        }
        strcat(pcm->name, " (synth)");
        gus->pcm = pcm;

        if (gus->codec_flag)
                kctl = snd_ctl_new1(&snd_gf1_pcm_volume_control1, gus);
        else
                kctl = snd_ctl_new1(&snd_gf1_pcm_volume_control, gus);
        if ((err = snd_ctl_add(card, kctl)) < 0)
                return err;
        kctl->id.index = control_index;

        if (rpcm)
                *rpcm = pcm;
        return 0;
}