pcm.c

Linux Kernel 2.6.9 for OMAP1710

static void snd_pcm_tick_timer_func(unsigned long data)
{
	snd_pcm_substream_t *substream = (snd_pcm_substream_t*) data;
	snd_pcm_tick_elapsed(substream);
}

int snd_pcm_open_substream(snd_pcm_t *pcm, int stream,
			   snd_pcm_substream_t **rsubstream)
{
	snd_pcm_str_t * pstr;
	snd_pcm_substream_t * substream;
	snd_pcm_runtime_t * runtime;
	snd_ctl_file_t *kctl;
	snd_card_t *card;
	struct list_head *list;
	int prefer_subdevice = -1;
	size_t size;

	snd_assert(rsubstream != NULL, return -EINVAL);
	*rsubstream = NULL;
	snd_assert(pcm != NULL, return -ENXIO);
	pstr = &pcm->streams[stream];
	if (pstr->substream == NULL)
		return -ENODEV;

	card = pcm->card;
	down_read(&card->controls_rwsem);
	list_for_each(list, &card->ctl_files) {
		kctl = snd_ctl_file(list);
		if (kctl->pid == current->pid) {
			prefer_subdevice = kctl->prefer_pcm_subdevice;
			break;
		}
	}
	up_read(&card->controls_rwsem);

	if (pstr->substream_count == 0)
		return -ENODEV;
	switch (stream) {
	case SNDRV_PCM_STREAM_PLAYBACK:
		if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
			for (substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream; substream; substream = substream->next) {
				if (SUBSTREAM_BUSY(substream))
					return -EAGAIN;
			}
		}
		break;
	case SNDRV_PCM_STREAM_CAPTURE:
		if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
			for (substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream; substream; substream = substream->next) {
				if (SUBSTREAM_BUSY(substream))
					return -EAGAIN;
			}
		}
		break;
	default:
		return -EINVAL;
	}

	if (prefer_subdevice >= 0) {
		for (substream = pstr->substream; substream; substream = substream->next)
			if (!SUBSTREAM_BUSY(substream) && substream->number == prefer_subdevice)
				goto __ok;
	}
	for (substream = pstr->substream; substream; substream = substream->next)
		if (!SUBSTREAM_BUSY(substream))
			break;
      __ok:
	if (substream == NULL)
		return -EAGAIN;

	runtime = kcalloc(1, sizeof(*runtime), GFP_KERNEL);
	if (runtime == NULL)
		return -ENOMEM;

	size = PAGE_ALIGN(sizeof(snd_pcm_mmap_status_t));
	runtime->status = snd_malloc_pages(size, GFP_KERNEL);
	if (runtime->status == NULL) {
		kfree(runtime);
		return -ENOMEM;
	}
	memset((void*)runtime->status, 0, size);

	size = PAGE_ALIGN(sizeof(snd_pcm_mmap_control_t));
	runtime->control = snd_malloc_pages(size, GFP_KERNEL);
	if (runtime->control == NULL) {
		snd_free_pages((void*)runtime->status, PAGE_ALIGN(sizeof(snd_pcm_mmap_status_t)));
		kfree(runtime);
		return -ENOMEM;
	}
	memset((void*)runtime->control, 0, size);

	init_waitqueue_head(&runtime->sleep);
	atomic_set(&runtime->mmap_count, 0);
	init_timer(&runtime->tick_timer);
	runtime->tick_timer.function = snd_pcm_tick_timer_func;
	runtime->tick_timer.data = (unsigned long) substream;

	runtime->status->state = SNDRV_PCM_STATE_OPEN;

	substream->runtime = runtime;
	substream->private_data = pcm->private_data;
	pstr->substream_opened++;
	*rsubstream = substream;
	return 0;
}

void snd_pcm_release_substream(snd_pcm_substream_t *substream)
{
	snd_pcm_runtime_t * runtime;
	substream->file = NULL;
	runtime = substream->runtime;
	snd_assert(runtime != NULL, return);
	if (runtime->private_free != NULL)
		runtime->private_free(runtime);
	snd_free_pages((void*)runtime->status, PAGE_ALIGN(sizeof(snd_pcm_mmap_status_t)));
	snd_free_pages((void*)runtime->control, PAGE_ALIGN(sizeof(snd_pcm_mmap_control_t)));
	if (runtime->hw_constraints.rules)
		kfree(runtime->hw_constraints.rules);
	kfree(runtime);
	substream->runtime = NULL;
	substream->pstr->substream_opened--;
}

static int snd_pcm_dev_register(snd_device_t *device)
{
	int idx, cidx, err;
	unsigned short minor;
	snd_pcm_substream_t *substream;
	struct list_head *list;
	char str[16];
	snd_pcm_t *pcm = device->device_data;

	snd_assert(pcm != NULL && device != NULL, return -ENXIO);
	down(&register_mutex);
	idx = (pcm->card->number * SNDRV_PCM_DEVICES) + pcm->device;
	if (snd_pcm_devices[idx]) {
		up(&register_mutex);
		return -EBUSY;
	}
	snd_pcm_devices[idx] = pcm;
	for (cidx = 0; cidx < 2; cidx++) {
		int devtype = -1;
		if (pcm->streams[cidx].substream == NULL)
			continue;
		switch (cidx) {
		case SNDRV_PCM_STREAM_PLAYBACK:
			sprintf(str, "pcmC%iD%ip", pcm->card->number, pcm->device);
			minor = SNDRV_MINOR_PCM_PLAYBACK + idx;
			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
			break;
		case SNDRV_PCM_STREAM_CAPTURE:
			sprintf(str, "pcmC%iD%ic", pcm->card->number, pcm->device);
			minor = SNDRV_MINOR_PCM_CAPTURE + idx;
			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
			break;
		}
		if ((err = snd_register_device(devtype, pcm->card, pcm->device, pcm->streams[cidx].reg, str)) < 0) {
			snd_pcm_devices[idx] = NULL;
			up(&register_mutex);
			return err;
		}
		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
			snd_pcm_timer_init(substream);
	}
	list_for_each(list, &snd_pcm_notify_list) {
		snd_pcm_notify_t *notify;
		notify = list_entry(list, snd_pcm_notify_t, list);
		notify->n_register(pcm);
	}
	up(&register_mutex);
	return 0;
}

static int snd_pcm_dev_disconnect(snd_device_t *device)
{
	snd_pcm_t *pcm = device->device_data;
	struct list_head *list;
	snd_pcm_substream_t *substream;
	int idx, cidx;

	down(&register_mutex);
	idx = (pcm->card->number * SNDRV_PCM_DEVICES) + pcm->device;
	snd_pcm_devices[idx] = NULL;
	for (cidx = 0; cidx < 2; cidx++)
		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
			if (substream->runtime)
				substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
	list_for_each(list, &snd_pcm_notify_list) {
		snd_pcm_notify_t *notify;
		notify = list_entry(list, snd_pcm_notify_t, list);
		notify->n_disconnect(pcm);
	}
	up(&register_mutex);
	return 0;
}

static int snd_pcm_dev_unregister(snd_device_t *device)
{
	int idx, cidx, devtype;
	snd_pcm_substream_t *substream;
	struct list_head *list;
	snd_pcm_t *pcm = device->device_data;

	snd_assert(pcm != NULL, return -ENXIO);
	down(&register_mutex);
	idx = (pcm->card->number * SNDRV_PCM_DEVICES) + pcm->device;
	snd_pcm_devices[idx] = NULL;
	for (cidx = 0; cidx < 2; cidx++) {
		devtype = -1;
		switch (cidx) {
		case SNDRV_PCM_STREAM_PLAYBACK:
			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
			break;
		case SNDRV_PCM_STREAM_CAPTURE:
			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
			break;
		}
		snd_unregister_device(devtype, pcm->card, pcm->device);
		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
			snd_pcm_timer_done(substream);
	}
	list_for_each(list, &snd_pcm_notify_list) {
		snd_pcm_notify_t *notify;
		notify = list_entry(list, snd_pcm_notify_t, list);
		notify->n_unregister(pcm);
	}
	up(&register_mutex);
	return snd_pcm_free(pcm);
}

int snd_pcm_notify(snd_pcm_notify_t *notify, int nfree)
{
	int idx;

	snd_assert(notify != NULL && notify->n_register != NULL && notify->n_unregister != NULL, return -EINVAL);
	down(&register_mutex);
	if (nfree) {
		list_del(&notify->list);
		for (idx = 0; idx < SNDRV_CARDS * SNDRV_PCM_DEVICES; idx++) {
			if (snd_pcm_devices[idx] == NULL)
				continue;
			notify->n_unregister(snd_pcm_devices[idx]);
		}
	} else {
		list_add_tail(&notify->list, &snd_pcm_notify_list);
		for (idx = 0; idx < SNDRV_CARDS * SNDRV_PCM_DEVICES; idx++) {
			if (snd_pcm_devices[idx] == NULL)
				continue;
			notify->n_register(snd_pcm_devices[idx]);
		}
	}
	up(&register_mutex);
	return 0;
}

/*
 *  Info interface
 */

static void snd_pcm_proc_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
{
	int idx;
	snd_pcm_t *pcm;

	down(&register_mutex);
	for (idx = 0; idx < SNDRV_CARDS * SNDRV_PCM_DEVICES; idx++) {
		pcm = snd_pcm_devices[idx];
		if (pcm == NULL)
			continue;
		snd_iprintf(buffer, "%02i-%02i: %s : %s", idx / SNDRV_PCM_DEVICES,
			    idx % SNDRV_PCM_DEVICES, pcm->id, pcm->name);
		if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
			snd_iprintf(buffer, " : playback %i", pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
		if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
			snd_iprintf(buffer, " : capture %i", pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
		snd_iprintf(buffer, "\n");
	}
	up(&register_mutex);
}

/*
 *  ENTRY functions
 */

static snd_info_entry_t *snd_pcm_proc_entry = NULL;

static int __init alsa_pcm_init(void)
{
	snd_info_entry_t *entry;

	snd_ctl_register_ioctl(snd_pcm_control_ioctl);
	if ((entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL)) != NULL) {
		snd_info_set_text_ops(entry, NULL, SNDRV_CARDS * SNDRV_PCM_DEVICES * 128, snd_pcm_proc_read);
		if (snd_info_register(entry) < 0) {
			snd_info_free_entry(entry);
			entry = NULL;
		}
	}
	snd_pcm_proc_entry = entry;
	return 0;
}

static void __exit alsa_pcm_exit(void)
{
	snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
	if (snd_pcm_proc_entry) {
		snd_info_unregister(snd_pcm_proc_entry);
		snd_pcm_proc_entry = NULL;
	}
}

module_init(alsa_pcm_init)
module_exit(alsa_pcm_exit)

EXPORT_SYMBOL(snd_pcm_devices);
EXPORT_SYMBOL(snd_pcm_new);
EXPORT_SYMBOL(snd_pcm_new_stream);
EXPORT_SYMBOL(snd_pcm_notify);
EXPORT_SYMBOL(snd_pcm_open_substream);
EXPORT_SYMBOL(snd_pcm_release_substream);
EXPORT_SYMBOL(snd_pcm_format_name);
EXPORT_SYMBOL(snd_pcm_subformat_name);
  /* pcm_native.c */
EXPORT_SYMBOL(snd_pcm_link_rwlock);
EXPORT_SYMBOL(snd_pcm_start);
#ifdef CONFIG_PM
EXPORT_SYMBOL(snd_pcm_suspend);
EXPORT_SYMBOL(snd_pcm_suspend_all);
#endif
EXPORT_SYMBOL(snd_pcm_kernel_playback_ioctl);
EXPORT_SYMBOL(snd_pcm_kernel_capture_ioctl);
EXPORT_SYMBOL(snd_pcm_kernel_ioctl);
EXPORT_SYMBOL(snd_pcm_open);
EXPORT_SYMBOL(snd_pcm_release);
EXPORT_SYMBOL(snd_pcm_playback_poll);
EXPORT_SYMBOL(snd_pcm_capture_poll);
EXPORT_SYMBOL(snd_pcm_mmap_data);
#if SNDRV_PCM_INFO_MMAP_IOMEM
EXPORT_SYMBOL(snd_pcm_lib_mmap_iomem);
#endif
 /* pcm_misc.c */
EXPORT_SYMBOL(snd_pcm_format_signed);
EXPORT_SYMBOL(snd_pcm_format_unsigned);
EXPORT_SYMBOL(snd_pcm_format_linear);
EXPORT_SYMBOL(snd_pcm_format_little_endian);
EXPORT_SYMBOL(snd_pcm_format_big_endian);
EXPORT_SYMBOL(snd_pcm_format_width);
EXPORT_SYMBOL(snd_pcm_format_physical_width);
EXPORT_SYMBOL(snd_pcm_format_size);
EXPORT_SYMBOL(snd_pcm_format_silence_64);
EXPORT_SYMBOL(snd_pcm_format_set_silence);
EXPORT_SYMBOL(snd_pcm_build_linear_format);
EXPORT_SYMBOL(snd_pcm_limit_hw_rates);