// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Routines for GF1 DMA control
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 */

#include <asm/dma.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/gus.h>

static void snd_gf1_dma_ack(struct snd_gus_card * gus)
{
 unsigned long flags;

 spin_lock_irqsave(&gus->reg_lock, flags);
 snd_gf1_write8(gus, SNDRV_GF1_GB_DRAM_DMA_CONTROL, 0x00);
 snd_gf1_look8(gus, SNDRV_GF1_GB_DRAM_DMA_CONTROL);
 spin_unlock_irqrestore(&gus->reg_lock, flags);
}

static void snd_gf1_dma_program(struct snd_gus_card * gus,
    unsigned int addr,
    unsigned long buf_addr,
    unsigned int count,
    unsigned int cmd)
{
 unsigned long flags;
 unsigned int address;
 unsigned char dma_cmd;
 unsigned int address_high;

 dev_dbg(gus->card->dev,
  "dma_transfer: addr=0x%x, buf=0x%lx, count=0x%x\n",
  addr, buf_addr, count);

 if (gus->gf1.dma1 > 3) {
  if (gus->gf1.enh_mode) {
   address = addr >> 1;
  } else {
   if (addr & 0x1f) {
    dev_dbg(gus->card->dev,
     "%s: unaligned address (0x%x)?\n",
     __func__, addr);
    return;
   }
   address = (addr & 0x000c0000) | ((addr & 0x0003ffff) >> 1);
  }
 } else {
  address = addr;
 }

 dma_cmd = SNDRV_GF1_DMA_ENABLE | (unsigned short) cmd;
#if 0
 dma_cmd |= 0x08;
#endif
 if (dma_cmd & SNDRV_GF1_DMA_16BIT) {
  count++;
  count &= ~1; /* align */
 }
 if (gus->gf1.dma1 > 3) {
  dma_cmd |= SNDRV_GF1_DMA_WIDTH16;
  count++;
  count &= ~1; /* align */
 }
 snd_gf1_dma_ack(gus);
 snd_dma_program(gus->gf1.dma1, buf_addr, count, dma_cmd & SNDRV_GF1_DMA_READ ? DMA_MODE_READ : DMA_MODE_WRITE);
#if 0
 dev_dbg(gus->card->dev,
  "address = 0x%x, count = 0x%x, dma_cmd = 0x%x\n",
  address << 1, count, dma_cmd);
#endif
 spin_lock_irqsave(&gus->reg_lock, flags);
 if (gus->gf1.enh_mode) {
  address_high = ((address >> 16) & 0x000000f0) | (address & 0x0000000f);
  snd_gf1_write16(gus, SNDRV_GF1_GW_DRAM_DMA_LOW, (unsigned short) (address >> 4));
  snd_gf1_write8(gus, SNDRV_GF1_GB_DRAM_DMA_HIGH, (unsigned char) address_high);
 } else
  snd_gf1_write16(gus, SNDRV_GF1_GW_DRAM_DMA_LOW, (unsigned short) (address >> 4));
 snd_gf1_write8(gus, SNDRV_GF1_GB_DRAM_DMA_CONTROL, dma_cmd);
 spin_unlock_irqrestore(&gus->reg_lock, flags);
}

static struct snd_gf1_dma_block *snd_gf1_dma_next_block(struct snd_gus_card * gus)
{
 struct snd_gf1_dma_block *block;

 /* PCM block have bigger priority than synthesizer one */
 if (gus->gf1.dma_data_pcm) {
  block = gus->gf1.dma_data_pcm;
  if (gus->gf1.dma_data_pcm_last == block) {
   gus->gf1.dma_data_pcm =
   gus->gf1.dma_data_pcm_last = NULL;
  } else {
   gus->gf1.dma_data_pcm = block->next;
  }
 } else if (gus->gf1.dma_data_synth) {
  block = gus->gf1.dma_data_synth;
  if (gus->gf1.dma_data_synth_last == block) {
   gus->gf1.dma_data_synth =
   gus->gf1.dma_data_synth_last = NULL;
  } else {
   gus->gf1.dma_data_synth = block->next;
  }
 } else {
  block = NULL;
 }
 if (block) {
  gus->gf1.dma_ack = block->ack;
  gus->gf1.dma_private_data = block->private_data;
 }
 return block;
}


static void snd_gf1_dma_interrupt(struct snd_gus_card * gus)
{
 struct snd_gf1_dma_block *block;

 snd_gf1_dma_ack(gus);
 if (gus->gf1.dma_ack)
  gus->gf1.dma_ack(gus, gus->gf1.dma_private_data);
 spin_lock(&gus->dma_lock);
 if (gus->gf1.dma_data_pcm == NULL &&
     gus->gf1.dma_data_synth == NULL) {
      gus->gf1.dma_ack = NULL;
  gus->gf1.dma_flags &= ~SNDRV_GF1_DMA_TRIGGER;
  spin_unlock(&gus->dma_lock);
  return;
 }
 block = snd_gf1_dma_next_block(gus);
 spin_unlock(&gus->dma_lock);
 if (!block)
  return;
 snd_gf1_dma_program(gus, block->addr, block->buf_addr, block->count, (unsigned short) block->cmd);
 kfree(block);
#if 0
 dev_dbg(gus->card->dev,
  "program dma (IRQ) - addr = 0x%x, buffer = 0x%lx, count = 0x%x, cmd = 0x%x\n",
  block->addr, block->buf_addr, block->count, block->cmd);
#endif
}

int snd_gf1_dma_init(struct snd_gus_card * gus)
{
 mutex_lock(&gus->dma_mutex);
 gus->gf1.dma_shared++;
 if (gus->gf1.dma_shared > 1) {
  mutex_unlock(&gus->dma_mutex);
  return 0;
 }
 gus->gf1.interrupt_handler_dma_write = snd_gf1_dma_interrupt;
 gus->gf1.dma_data_pcm = 
 gus->gf1.dma_data_pcm_last =
 gus->gf1.dma_data_synth = 
 gus->gf1.dma_data_synth_last = NULL;
 mutex_unlock(&gus->dma_mutex);
 return 0;
}

int snd_gf1_dma_done(struct snd_gus_card * gus)
{
 struct snd_gf1_dma_block *block;

 mutex_lock(&gus->dma_mutex);
 gus->gf1.dma_shared--;
 if (!gus->gf1.dma_shared) {
  snd_dma_disable(gus->gf1.dma1);
  snd_gf1_set_default_handlers(gus, SNDRV_GF1_HANDLER_DMA_WRITE);
  snd_gf1_dma_ack(gus);
  while ((block = gus->gf1.dma_data_pcm)) {
   gus->gf1.dma_data_pcm = block->next;
   kfree(block);
  }
  while ((block = gus->gf1.dma_data_synth)) {
   gus->gf1.dma_data_synth = block->next;
   kfree(block);
  }
  gus->gf1.dma_data_pcm_last =
  gus->gf1.dma_data_synth_last = NULL;
 }
 mutex_unlock(&gus->dma_mutex);
 return 0;
}

int snd_gf1_dma_transfer_block(struct snd_gus_card * gus,
          struct snd_gf1_dma_block * __block,
          int atomic,
          int synth)
{
 unsigned long flags;
 struct snd_gf1_dma_block *block;

 block = kmalloc(sizeof(*block), atomic ? GFP_ATOMIC : GFP_KERNEL);
 if (!block)
  return -ENOMEM;

 *block = *__block;
 block->next = NULL;

 dev_dbg(gus->card->dev,
  "addr = 0x%x, buffer = 0x%lx, count = 0x%x, cmd = 0x%x\n",
  block->addr, (long) block->buffer, block->count,
  block->cmd);

 dev_dbg(gus->card->dev,
  "gus->gf1.dma_data_pcm_last = 0x%lx\n",
  (long)gus->gf1.dma_data_pcm_last);
 dev_dbg(gus->card->dev,
  "gus->gf1.dma_data_pcm = 0x%lx\n",
  (long)gus->gf1.dma_data_pcm);

 spin_lock_irqsave(&gus->dma_lock, flags);
 if (synth) {
  if (gus->gf1.dma_data_synth_last) {
   gus->gf1.dma_data_synth_last->next = block;
   gus->gf1.dma_data_synth_last = block;
  } else {
   gus->gf1.dma_data_synth = 
   gus->gf1.dma_data_synth_last = block;
  }
 } else {
  if (gus->gf1.dma_data_pcm_last) {
   gus->gf1.dma_data_pcm_last->next = block;
   gus->gf1.dma_data_pcm_last = block;
  } else {
   gus->gf1.dma_data_pcm = 
   gus->gf1.dma_data_pcm_last = block;
  }
 }
 if (!(gus->gf1.dma_flags & SNDRV_GF1_DMA_TRIGGER)) {
  gus->gf1.dma_flags |= SNDRV_GF1_DMA_TRIGGER;
  block = snd_gf1_dma_next_block(gus);
  spin_unlock_irqrestore(&gus->dma_lock, flags);
  if (block == NULL)
   return 0;
  snd_gf1_dma_program(gus, block->addr, block->buf_addr, block->count, (unsigned short) block->cmd);
  kfree(block);
  return 0;
 }
 spin_unlock_irqrestore(&gus->dma_lock, flags);
 return 0;
}