aica.c

linux 内核源代码

	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;
	dreamcastcard = kcontrol->private_data;
	if (unlikely(!dreamcastcard->channel))
		return -ETXTBSY;
	if (unlikely(dreamcastcard->channel->vol ==
		     ucontrol->value.integer.value[0]))
		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 firware 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 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 __init 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;
	dreamcastcard->card =
	    snd_card_new(index, SND_AICA_DRIVER, THIS_MODULE, 0);
	if (unlikely(!dreamcastcard->card)) {
		kfree(dreamcastcard);
		return -ENODEV;
	}
	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\n");
	return 0;
      freedreamcast:
	snd_card_free(dreamcastcard->card);
	kfree(dreamcastcard);
	return err;
}

static struct platform_driver snd_aica_driver = {
	.probe = snd_aica_probe,
	.remove = 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 (unlikely(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);