sound/soc/soc-pcm.c

Source file repositories/reference/linux-study-clean/sound/soc/soc-pcm.c

File Facts

System
Linux kernel
Corpus path
sound/soc/soc-pcm.c
Extension
.c
Size
85245 bytes
Lines
3124
Domain
Driver Families
Bucket
sound/soc
Inferred role
Driver Families: operation-table or driver-model contract
Status
pattern implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

static const struct file_operations dpcm_state_fops = {
	.open = simple_open,
	.read = dpcm_state_read_file,
	.llseek = default_llseek,
};

void soc_dpcm_debugfs_add(struct snd_soc_pcm_runtime *rtd)
{
	if (!rtd->dai_link->dynamic)
		return;

	if (!rtd->card->debugfs_card_root)
		return;

	rtd->debugfs_dpcm_root = debugfs_create_dir(rtd->dai_link->name,
						    rtd->card->debugfs_card_root);

	debugfs_create_file("state", 0444, rtd->debugfs_dpcm_root,
			    rtd, &dpcm_state_fops);
}

static void dpcm_create_debugfs_state(struct snd_soc_dpcm *dpcm, int stream)
{
	char *name;

	name = kasprintf(GFP_KERNEL, "%s:%s", dpcm->be->dai_link->name,
			 snd_pcm_direction_name(stream));
	if (name) {
		dpcm->debugfs_state = debugfs_create_dir(
			name, dpcm->fe->debugfs_dpcm_root);
		debugfs_create_u32("state", 0644, dpcm->debugfs_state,
				   &dpcm->state);
		kfree(name);
	}
}

static void dpcm_remove_debugfs_state(struct snd_soc_dpcm *dpcm)
{
	debugfs_remove_recursive(dpcm->debugfs_state);
}

#else
static inline void dpcm_create_debugfs_state(struct snd_soc_dpcm *dpcm,
					     int stream)
{
}

static inline void dpcm_remove_debugfs_state(struct snd_soc_dpcm *dpcm)
{
}
#endif

/* Set FE's runtime_update state; the state is protected via PCM stream lock
 * for avoiding the race with trigger callback.
 * If the state is unset and a trigger is pending while the previous operation,
 * process the pending trigger action here.
 */
static int dpcm_fe_dai_do_trigger(struct snd_pcm_substream *substream, int cmd);
static void dpcm_set_fe_update_state(struct snd_soc_pcm_runtime *fe,
				     int stream, enum snd_soc_dpcm_update state)
{
	struct snd_pcm_substream *substream =
		snd_soc_dpcm_get_substream(fe, stream);

	snd_pcm_stream_lock_irq(substream);
	if (state == SND_SOC_DPCM_UPDATE_NO && fe->dpcm[stream].trigger_pending) {
		dpcm_fe_dai_do_trigger(substream,
				       fe->dpcm[stream].trigger_pending - 1);
		fe->dpcm[stream].trigger_pending = 0;
	}
	fe->dpcm[stream].runtime_update = state;
	snd_pcm_stream_unlock_irq(substream);
}

static void dpcm_set_be_update_state(struct snd_soc_pcm_runtime *be,
				     int stream, enum snd_soc_dpcm_update state)
{
	be->dpcm[stream].runtime_update = state;
}

/**
 * snd_soc_runtime_action() - Increment/Decrement active count for
 * PCM runtime components
 * @rtd: ASoC PCM runtime that is activated
 * @stream: Direction of the PCM stream
 * @action: Activate stream if 1. Deactivate if -1.
 *
 * Increments/Decrements the active count for all the DAIs and components
 * attached to a PCM runtime.
 * Should typically be called when a stream is opened.

Annotation

Implementation Notes