/*
  * This code is licenced under 
  * the General Public Licence
  * version 2
  *
  * Copyright Adrian McMenamin 2005, 2006, 2007
  * <adrian@mcmen.demon.co.uk>
  * Requires firmware (BSD licenced) available from:
  * http://linuxdc.cvs.sourceforge.net/linuxdc/linux-sh-dc/sound/oss/aica/firmware/
  * or the maintainer
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as published by
  * the Free Software Foundation.
  *
  * 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 <linux/init.h>
  #include <linux/jiffies.h>
  #include <linux/slab.h>
  #include <linux/time.h>
  #include <linux/wait.h>

  #include <linux/module.h>

  #include <linux/platform_device.h>
  #include <linux/firmware.h>
  #include <linux/timer.h>
  #include <linux/delay.h>
  #include <linux/workqueue.h>

  #include <sound/core.h>
  #include <sound/control.h>
  #include <sound/pcm.h>
  #include <sound/initval.h>
  #include <sound/info.h>
  #include <asm/io.h>
  #include <asm/dma.h>

  #include <mach/sysasic.h>

  #include "aica.h"
  
  MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
  MODULE_DESCRIPTION("Dreamcast AICA sound (pcm) driver");
  MODULE_LICENSE("GPL");
  MODULE_SUPPORTED_DEVICE("{{Yamaha/SEGA, AICA}}");

  MODULE_FIRMWARE("aica_firmware.bin");

  
  /* module parameters */
  #define CARD_NAME "AICA"
  static int index = -1;
  static char *id;

  static bool enable = 1;

  module_param(index, int, 0444);
  MODULE_PARM_DESC(index, "Index value for " CARD_NAME " soundcard.");
  module_param(id, charp, 0444);
  MODULE_PARM_DESC(id, "ID string for " CARD_NAME " soundcard.");
  module_param(enable, bool, 0644);
  MODULE_PARM_DESC(enable, "Enable " CARD_NAME " soundcard.");
  
  /* Use workqueue */

  static struct workqueue_struct *aica_queue;
  
  /* Simple platform device */
  static struct platform_device *pd;
  static struct resource aica_memory_space[2] = {
  	{
  	 .name = "AICA ARM CONTROL",
  	 .start = ARM_RESET_REGISTER,
  	 .flags = IORESOURCE_MEM,
  	 .end = ARM_RESET_REGISTER + 3,
  	 },
  	{
  	 .name = "AICA Sound RAM",
  	 .start = SPU_MEMORY_BASE,
  	 .flags = IORESOURCE_MEM,
  	 .end = SPU_MEMORY_BASE + 0x200000 - 1,
  	 },
  };
  
  /* SPU specific functions */
  /* spu_write_wait - wait for G2-SH FIFO to clear */
  static void spu_write_wait(void)
  {
  	int time_count;
  	time_count = 0;
  	while (1) {
  		if (!(readl(G2_FIFO) & 0x11))
  			break;
  		/* To ensure hardware failure doesn't wedge kernel */
  		time_count++;

  		if (time_count > 0x10000) {
  			snd_printk
  			    ("WARNING: G2 FIFO appears to be blocked.
  ");

  			break;
  		}
  	}
  }
  
  /* spu_memset - write to memory in SPU address space */
  static void spu_memset(u32 toi, u32 what, int length)
  {
  	int i;

  	unsigned long flags;

  	if (snd_BUG_ON(length % 4))
  		return;

  	for (i = 0; i < length; i++) {
  		if (!(i % 8))
  			spu_write_wait();

  		local_irq_save(flags);

  		writel(what, toi + SPU_MEMORY_BASE);

  		local_irq_restore(flags);

  		toi++;
  	}
  }
  
  /* spu_memload - write to SPU address space */
  static void spu_memload(u32 toi, void *from, int length)
  {

  	unsigned long flags;

  	u32 *froml = from;
  	u32 __iomem *to = (u32 __iomem *) (SPU_MEMORY_BASE + toi);
  	int i;
  	u32 val;
  	length = DIV_ROUND_UP(length, 4);
  	spu_write_wait();
  	for (i = 0; i < length; i++) {
  		if (!(i % 8))
  			spu_write_wait();
  		val = *froml;

  		local_irq_save(flags);

  		writel(val, to);

  		local_irq_restore(flags);

  		froml++;
  		to++;
  	}
  }
  
  /* spu_disable - set spu registers to stop sound output */
  static void spu_disable(void)
  {
  	int i;

  	unsigned long flags;

  	u32 regval;
  	spu_write_wait();
  	regval = readl(ARM_RESET_REGISTER);
  	regval |= 1;
  	spu_write_wait();

  	local_irq_save(flags);

  	writel(regval, ARM_RESET_REGISTER);

  	local_irq_restore(flags);

  	for (i = 0; i < 64; i++) {
  		spu_write_wait();
  		regval = readl(SPU_REGISTER_BASE + (i * 0x80));
  		regval = (regval & ~0x4000) | 0x8000;
  		spu_write_wait();

  		local_irq_save(flags);

  		writel(regval, SPU_REGISTER_BASE + (i * 0x80));

  		local_irq_restore(flags);

  	}
  }
  
  /* spu_enable - set spu registers to enable sound output */
  static void spu_enable(void)
  {

  	unsigned long flags;

  	u32 regval = readl(ARM_RESET_REGISTER);
  	regval &= ~1;
  	spu_write_wait();

  	local_irq_save(flags);

  	writel(regval, ARM_RESET_REGISTER);

  	local_irq_restore(flags);

  }
  
  /* 
   * Halt the sound processor, clear the memory,
   * load some default ARM7 code, and then restart ARM7
  */
  static void spu_reset(void)
  {

  	unsigned long flags;

  	spu_disable();
  	spu_memset(0, 0, 0x200000 / 4);
  	/* Put ARM7 in endless loop */

  	local_irq_save(flags);

  	__raw_writel(0xea000002, SPU_MEMORY_BASE);

  	local_irq_restore(flags);

  	spu_enable();
  }
  
  /* aica_chn_start - write to spu to start playback */
  static void aica_chn_start(void)
  {

  	unsigned long flags;

  	spu_write_wait();

  	local_irq_save(flags);

  	writel(AICA_CMD_KICK | AICA_CMD_START, (u32 *) AICA_CONTROL_POINT);

  	local_irq_restore(flags);

  }
  
  /* aica_chn_halt - write to spu to halt playback */
  static void aica_chn_halt(void)
  {

  	unsigned long flags;

  	spu_write_wait();

  	local_irq_save(flags);

  	writel(AICA_CMD_KICK | AICA_CMD_STOP, (u32 *) AICA_CONTROL_POINT);

  	local_irq_restore(flags);

  }
  
  /* ALSA code below */
  static struct snd_pcm_hardware snd_pcm_aica_playback_hw = {
  	.info = (SNDRV_PCM_INFO_NONINTERLEAVED),
  	.formats =
  	    (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE |
  	     SNDRV_PCM_FMTBIT_IMA_ADPCM),
  	.rates = SNDRV_PCM_RATE_8000_48000,
  	.rate_min = 8000,
  	.rate_max = 48000,
  	.channels_min = 1,
  	.channels_max = 2,
  	.buffer_bytes_max = AICA_BUFFER_SIZE,
  	.period_bytes_min = AICA_PERIOD_SIZE,
  	.period_bytes_max = AICA_PERIOD_SIZE,
  	.periods_min = AICA_PERIOD_NUMBER,
  	.periods_max = AICA_PERIOD_NUMBER,
  };
  
  static int aica_dma_transfer(int channels, int buffer_size,
  			     struct snd_pcm_substream *substream)
  {
  	int q, err, period_offset;
  	struct snd_card_aica *dreamcastcard;
  	struct snd_pcm_runtime *runtime;

  	unsigned long flags;

  	err = 0;

  	dreamcastcard = substream->pcm->private_data;
  	period_offset = dreamcastcard->clicks;
  	period_offset %= (AICA_PERIOD_NUMBER / channels);
  	runtime = substream->runtime;
  	for (q = 0; q < channels; q++) {

  		local_irq_save(flags);

  		err = dma_xfer(AICA_DMA_CHANNEL,

  			       (unsigned long) (runtime->dma_area +
  						(AICA_BUFFER_SIZE * q) /
  						channels +
  						AICA_PERIOD_SIZE *
  						period_offset),

  			       AICA_CHANNEL0_OFFSET + q * CHANNEL_OFFSET +
  			       AICA_PERIOD_SIZE * period_offset,
  			       buffer_size / channels, AICA_DMA_MODE);

  		if (unlikely(err < 0)) {
  			local_irq_restore(flags);

  			break;

  		}

  		dma_wait_for_completion(AICA_DMA_CHANNEL);

  		local_irq_restore(flags);

  	}
  	return err;
  }
  
  static void startup_aica(struct snd_card_aica *dreamcastcard)
  {
  	spu_memload(AICA_CHANNEL0_CONTROL_OFFSET,

  		    dreamcastcard->channel, sizeof(struct aica_channel));

  	aica_chn_start();
  }
  
  static void run_spu_dma(struct work_struct *work)
  {
  	int buffer_size;

  	struct snd_pcm_runtime *runtime;
  	struct snd_card_aica *dreamcastcard;

  	dreamcastcard =
  	    container_of(work, struct snd_card_aica, spu_dma_work);
  	runtime = dreamcastcard->substream->runtime;

  	if (unlikely(dreamcastcard->dma_check == 0)) {

  		buffer_size =
  		    frames_to_bytes(runtime, runtime->buffer_size);

  		if (runtime->channels > 1)
  			dreamcastcard->channel->flags |= 0x01;

  		aica_dma_transfer(runtime->channels, buffer_size,
  				  dreamcastcard->substream);

  		startup_aica(dreamcastcard);
  		dreamcastcard->clicks =
  		    buffer_size / (AICA_PERIOD_SIZE * runtime->channels);
  		return;
  	} else {
  		aica_dma_transfer(runtime->channels,
  				  AICA_PERIOD_SIZE * runtime->channels,

  				  dreamcastcard->substream);

  		snd_pcm_period_elapsed(dreamcastcard->substream);
  		dreamcastcard->clicks++;
  		if (unlikely(dreamcastcard->clicks >= AICA_PERIOD_NUMBER))

  			dreamcastcard->clicks %= AICA_PERIOD_NUMBER;

  		mod_timer(&dreamcastcard->timer, jiffies + 1);
  	}
  }
  
  static void aica_period_elapsed(unsigned long timer_var)
  {
  	/*timer function - so cannot sleep */
  	int play_period;
  	struct snd_pcm_runtime *runtime;
  	struct snd_pcm_substream *substream;
  	struct snd_card_aica *dreamcastcard;

  	substream = (struct snd_pcm_substream *) timer_var;

  	runtime = substream->runtime;
  	dreamcastcard = substream->pcm->private_data;
  	/* Have we played out an additional period? */
  	play_period =
  	    frames_to_bytes(runtime,
  			    readl
  			    (AICA_CONTROL_CHANNEL_SAMPLE_NUMBER)) /
  	    AICA_PERIOD_SIZE;
  	if (play_period == dreamcastcard->current_period) {
  		/* reschedule the timer */
  		mod_timer(&(dreamcastcard->timer), jiffies + 1);
  		return;
  	}
  	if (runtime->channels > 1)
  		dreamcastcard->current_period = play_period;
  	if (unlikely(dreamcastcard->dma_check == 0))
  		dreamcastcard->dma_check = 1;

  	queue_work(aica_queue, &(dreamcastcard->spu_dma_work));

  }
  
  static void spu_begin_dma(struct snd_pcm_substream *substream)
  {

  	struct snd_card_aica *dreamcastcard;
  	struct snd_pcm_runtime *runtime;
  	runtime = substream->runtime;
  	dreamcastcard = substream->pcm->private_data;

  	/*get the queue to do the work */
  	queue_work(aica_queue, &(dreamcastcard->spu_dma_work));

  	/* Timer may already be running */
  	if (unlikely(dreamcastcard->timer.data)) {
  		mod_timer(&dreamcastcard->timer, jiffies + 4);
  		return;
  	}
  	init_timer(&(dreamcastcard->timer));

  	dreamcastcard->timer.data = (unsigned long) substream;

  	dreamcastcard->timer.function = aica_period_elapsed;
  	dreamcastcard->timer.expires = jiffies + 4;
  	add_timer(&(dreamcastcard->timer));
  }
  
  static int snd_aicapcm_pcm_open(struct snd_pcm_substream
  				*substream)
  {
  	struct snd_pcm_runtime *runtime;
  	struct aica_channel *channel;
  	struct snd_card_aica *dreamcastcard;
  	if (!enable)
  		return -ENOENT;
  	dreamcastcard = substream->pcm->private_data;
  	channel = kmalloc(sizeof(struct aica_channel), GFP_KERNEL);
  	if (!channel)
  		return -ENOMEM;
  	/* set defaults for channel */
  	channel->sfmt = SM_8BIT;
  	channel->cmd = AICA_CMD_START;
  	channel->vol = dreamcastcard->master_volume;
  	channel->pan = 0x80;
  	channel->pos = 0;
  	channel->flags = 0;	/* default to mono */
  	dreamcastcard->channel = channel;
  	runtime = substream->runtime;
  	runtime->hw = snd_pcm_aica_playback_hw;
  	spu_enable();
  	dreamcastcard->clicks = 0;
  	dreamcastcard->current_period = 0;
  	dreamcastcard->dma_check = 0;
  	return 0;
  }
  
  static int snd_aicapcm_pcm_close(struct snd_pcm_substream
  				 *substream)
  {
  	struct snd_card_aica *dreamcastcard = substream->pcm->private_data;

  	flush_workqueue(aica_queue);
  	if (dreamcastcard->timer.data)
  		del_timer(&dreamcastcard->timer);

  	kfree(dreamcastcard->channel);
  	spu_disable();
  	return 0;
  }
  
  static int snd_aicapcm_pcm_hw_free(struct snd_pcm_substream
  				   *substream)
  {
  	/* Free the DMA buffer */
  	return snd_pcm_lib_free_pages(substream);
  }
  
  static int snd_aicapcm_pcm_hw_params(struct snd_pcm_substream
  				     *substream, struct snd_pcm_hw_params
  				     *hw_params)
  {
  	/* Allocate a DMA buffer using ALSA built-ins */
  	return

  	    snd_pcm_lib_malloc_pages(substream,
  				     params_buffer_bytes(hw_params));

  }
  
  static int snd_aicapcm_pcm_prepare(struct snd_pcm_substream
  				   *substream)
  {
  	struct snd_card_aica *dreamcastcard = substream->pcm->private_data;
  	if ((substream->runtime)->format == SNDRV_PCM_FORMAT_S16_LE)
  		dreamcastcard->channel->sfmt = SM_16BIT;
  	dreamcastcard->channel->freq = substream->runtime->rate;
  	dreamcastcard->substream = substream;
  	return 0;
  }
  
  static int snd_aicapcm_pcm_trigger(struct snd_pcm_substream
  				   *substream, int cmd)
  {

  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  		spu_begin_dma(substream);
  		break;
  	case SNDRV_PCM_TRIGGER_STOP:

  		aica_chn_halt();
  		break;
  	default:
  		return -EINVAL;
  	}
  	return 0;
  }
  
  static unsigned long snd_aicapcm_pcm_pointer(struct snd_pcm_substream
  					     *substream)
  {
  	return readl(AICA_CONTROL_CHANNEL_SAMPLE_NUMBER);
  }
  
  static struct snd_pcm_ops snd_aicapcm_playback_ops = {
  	.open = snd_aicapcm_pcm_open,
  	.close = snd_aicapcm_pcm_close,
  	.ioctl = snd_pcm_lib_ioctl,
  	.hw_params = snd_aicapcm_pcm_hw_params,
  	.hw_free = snd_aicapcm_pcm_hw_free,
  	.prepare = snd_aicapcm_pcm_prepare,
  	.trigger = snd_aicapcm_pcm_trigger,
  	.pointer = snd_aicapcm_pcm_pointer,
  };
  
  /* TO DO: set up to handle more than one pcm instance */
  static int __init snd_aicapcmchip(struct snd_card_aica
  				  *dreamcastcard, int pcm_index)
  {
  	struct snd_pcm *pcm;
  	int err;
  	/* AICA has no capture ability */
  	err =

  	    snd_pcm_new(dreamcastcard->card, "AICA PCM", pcm_index, 1, 0,
  			&pcm);

  	if (unlikely(err < 0))
  		return err;
  	pcm->private_data = dreamcastcard;
  	strcpy(pcm->name, "AICA PCM");
  	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
  			&snd_aicapcm_playback_ops);
  	/* Allocate the DMA buffers */
  	err =
  	    snd_pcm_lib_preallocate_pages_for_all(pcm,
  						  SNDRV_DMA_TYPE_CONTINUOUS,
  						  snd_dma_continuous_data
  						  (GFP_KERNEL),
  						  AICA_BUFFER_SIZE,
  						  AICA_BUFFER_SIZE);
  	return err;
  }
  
  /* Mixer controls */

  #define aica_pcmswitch_info		snd_ctl_boolean_mono_info

  
  static int aica_pcmswitch_get(struct snd_kcontrol *kcontrol,
  			      struct snd_ctl_elem_value *ucontrol)
  {
  	ucontrol->value.integer.value[0] = 1;	/* TO DO: Fix me */
  	return 0;
  }
  
  static int aica_pcmswitch_put(struct snd_kcontrol *kcontrol,
  			      struct snd_ctl_elem_value *ucontrol)
  {
  	if (ucontrol->value.integer.value[0] == 1)
  		return 0;	/* TO DO: Fix me */
  	else
  		aica_chn_halt();
  	return 0;
  }
  
  static int aica_pcmvolume_info(struct snd_kcontrol *kcontrol,
  			       struct snd_ctl_elem_info *uinfo)
  {
  	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
  	uinfo->count = 1;
  	uinfo->value.integer.min = 0;
  	uinfo->value.integer.max = 0xFF;
  	return 0;
  }
  
  static int aica_pcmvolume_get(struct snd_kcontrol *kcontrol,
  			      struct snd_ctl_elem_value *ucontrol)
  {
  	struct snd_card_aica *dreamcastcard;
  	dreamcastcard = kcontrol->private_data;
  	if (unlikely(!dreamcastcard->channel))
  		return -ETXTBSY;	/* we've not yet been set up */
  	ucontrol->value.integer.value[0] = dreamcastcard->channel->vol;
  	return 0;
  }
  
  static int aica_pcmvolume_put(struct snd_kcontrol *kcontrol,
  			      struct snd_ctl_elem_value *ucontrol)
  {
  	struct snd_card_aica *dreamcastcard;

  	unsigned int vol;

  	dreamcastcard = kcontrol->private_data;
  	if (unlikely(!dreamcastcard->channel))
  		return -ETXTBSY;

  	vol = ucontrol->value.integer.value[0];
  	if (vol > 0xff)
  		return -EINVAL;
  	if (unlikely(dreamcastcard->channel->vol == vol))

  		return 0;
  	dreamcastcard->channel->vol = ucontrol->value.integer.value[0];
  	dreamcastcard->master_volume = ucontrol->value.integer.value[0];
  	spu_memload(AICA_CHANNEL0_CONTROL_OFFSET,

  		    dreamcastcard->channel, sizeof(struct aica_channel));

  	return 1;
  }
  
  static struct snd_kcontrol_new snd_aica_pcmswitch_control __devinitdata = {
  	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
  	.name = "PCM Playback Switch",
  	.index = 0,
  	.info = aica_pcmswitch_info,
  	.get = aica_pcmswitch_get,
  	.put = aica_pcmswitch_put
  };
  
  static struct snd_kcontrol_new snd_aica_pcmvolume_control __devinitdata = {
  	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
  	.name = "PCM Playback Volume",
  	.index = 0,
  	.info = aica_pcmvolume_info,
  	.get = aica_pcmvolume_get,
  	.put = aica_pcmvolume_put
  };
  
  static int load_aica_firmware(void)
  {
  	int err;
  	const struct firmware *fw_entry;
  	spu_reset();
  	err = request_firmware(&fw_entry, "aica_firmware.bin", &pd->dev);
  	if (unlikely(err))
  		return err;

  	/* write firmware into memory */

  	spu_disable();
  	spu_memload(0, fw_entry->data, fw_entry->size);
  	spu_enable();
  	release_firmware(fw_entry);
  	return err;
  }
  
  static int __devinit add_aicamixer_controls(struct snd_card_aica
  					    *dreamcastcard)
  {
  	int err;
  	err = snd_ctl_add
  	    (dreamcastcard->card,
  	     snd_ctl_new1(&snd_aica_pcmvolume_control, dreamcastcard));
  	if (unlikely(err < 0))
  		return err;
  	err = snd_ctl_add
  	    (dreamcastcard->card,
  	     snd_ctl_new1(&snd_aica_pcmswitch_control, dreamcastcard));
  	if (unlikely(err < 0))
  		return err;
  	return 0;
  }

  static int __devexit snd_aica_remove(struct platform_device *devptr)

  {
  	struct snd_card_aica *dreamcastcard;
  	dreamcastcard = platform_get_drvdata(devptr);
  	if (unlikely(!dreamcastcard))
  		return -ENODEV;
  	snd_card_free(dreamcastcard->card);
  	kfree(dreamcastcard);
  	platform_set_drvdata(devptr, NULL);
  	return 0;
  }

  static int __devinit snd_aica_probe(struct platform_device *devptr)

  {
  	int err;
  	struct snd_card_aica *dreamcastcard;
  	dreamcastcard = kmalloc(sizeof(struct snd_card_aica), GFP_KERNEL);
  	if (unlikely(!dreamcastcard))
  		return -ENOMEM;

  	err = snd_card_create(index, SND_AICA_DRIVER, THIS_MODULE, 0,
  			      &dreamcastcard->card);
  	if (unlikely(err < 0)) {

  		kfree(dreamcastcard);

  		return err;

  	}
  	strcpy(dreamcastcard->card->driver, "snd_aica");
  	strcpy(dreamcastcard->card->shortname, SND_AICA_DRIVER);
  	strcpy(dreamcastcard->card->longname,
  	       "Yamaha AICA Super Intelligent Sound Processor for SEGA Dreamcast");

  	/* Prepare to use the queue */
  	INIT_WORK(&(dreamcastcard->spu_dma_work), run_spu_dma);

  	/* Load the PCM 'chip' */
  	err = snd_aicapcmchip(dreamcastcard, 0);
  	if (unlikely(err < 0))
  		goto freedreamcast;
  	snd_card_set_dev(dreamcastcard->card, &devptr->dev);
  	dreamcastcard->timer.data = 0;
  	dreamcastcard->channel = NULL;
  	/* Add basic controls */
  	err = add_aicamixer_controls(dreamcastcard);
  	if (unlikely(err < 0))
  		goto freedreamcast;
  	/* Register the card with ALSA subsystem */
  	err = snd_card_register(dreamcastcard->card);
  	if (unlikely(err < 0))
  		goto freedreamcast;
  	platform_set_drvdata(devptr, dreamcastcard);
  	aica_queue = create_workqueue(CARD_NAME);
  	if (unlikely(!aica_queue))
  		goto freedreamcast;
  	snd_printk
  	    ("ALSA Driver for Yamaha AICA Super Intelligent Sound Processor
  ");
  	return 0;
        freedreamcast:
  	snd_card_free(dreamcastcard->card);
  	kfree(dreamcastcard);
  	return err;
  }
  
  static struct platform_driver snd_aica_driver = {
  	.probe = snd_aica_probe,

  	.remove = __devexit_p(snd_aica_remove),

  	.driver = {
  		   .name = SND_AICA_DRIVER},
  };
  
  static int __init aica_init(void)
  {
  	int err;
  	err = platform_driver_register(&snd_aica_driver);
  	if (unlikely(err < 0))
  		return err;
  	pd = platform_device_register_simple(SND_AICA_DRIVER, -1,
  					     aica_memory_space, 2);

  	if (IS_ERR(pd)) {

  		platform_driver_unregister(&snd_aica_driver);
  		return PTR_ERR(pd);
  	}
  	/* Load the firmware */
  	return load_aica_firmware();
  }
  
  static void __exit aica_exit(void)
  {

  	/* Destroy the aica kernel thread            *
  	 * being extra cautious to check if it exists*/
  	if (likely(aica_queue))
  		destroy_workqueue(aica_queue);

  	platform_device_unregister(pd);
  	platform_driver_unregister(&snd_aica_driver);
  	/* Kill any sound still playing and reset ARM7 to safe state */
  	spu_reset();
  }
  
  module_init(aica_init);
  module_exit(aica_exit);