ASoC: meson: Use managed DMA buffer allocation

Using a managed buffer will pre-allocate the buffer using
snd_pcm_lib_preallocate_pages() and automatically free it when the PCM is
destroyed.

In addition it will call snd_pcm_lib_malloc_pages() before the driver's
hw_params() callback and snd_pcm_lib_free_pages() after the driver's
hw_free() callback.

This slightly reduces the boilerplate code of the driver.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Tested-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20201218154544.25513-1-lars@metafoo.deSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/meson/aiu-fifo-i2s.c

@@ -124,7 +124,6 @@ const struct snd_soc_dai_ops aiu_fifo_i2s_dai_ops = {
 	.trigger	= aiu_fifo_i2s_trigger,
 	.prepare	= aiu_fifo_i2s_prepare,
 	.hw_params	= aiu_fifo_i2s_hw_params,
-	.hw_free	= aiu_fifo_hw_free,
 	.startup	= aiu_fifo_startup,
 	.shutdown	= aiu_fifo_shutdown,
 };

sound/soc/meson/aiu-fifo-spdif.c

@@ -158,7 +158,6 @@ const struct snd_soc_dai_ops aiu_fifo_spdif_dai_ops = {
 	.trigger	= fifo_spdif_trigger,
 	.prepare	= fifo_spdif_prepare,
 	.hw_params	= fifo_spdif_hw_params,
-	.hw_free	= aiu_fifo_hw_free,
 	.startup	= aiu_fifo_startup,
 	.shutdown	= aiu_fifo_shutdown,
 };

sound/soc/meson/aiu-fifo.c

@@ -99,11 +99,6 @@ int aiu_fifo_hw_params(struct snd_pcm_substream *substream,
 	struct snd_soc_component *component = dai->component;
 	struct aiu_fifo *fifo = dai->playback_dma_data;
 	dma_addr_t end;
-	int ret;
-
-	ret = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
-	if (ret < 0)
-		return ret;
 
 	/* Setup the fifo boundaries */
 	end = runtime->dma_addr + runtime->dma_bytes - fifo->fifo_block;
@@ -124,12 +119,6 @@ int aiu_fifo_hw_params(struct snd_pcm_substream *substream,
 	return 0;
 }
 
-int aiu_fifo_hw_free(struct snd_pcm_substream *substream,
-		     struct snd_soc_dai *dai)
-{
-	return snd_pcm_lib_free_pages(substream);
-}
-
 static irqreturn_t aiu_fifo_isr(int irq, void *dev_id)
 {
 	struct snd_pcm_substream *playback = dev_id;
@@ -187,15 +176,12 @@ void aiu_fifo_shutdown(struct snd_pcm_substream *substream,
 int aiu_fifo_pcm_new(struct snd_soc_pcm_runtime *rtd,
 		     struct snd_soc_dai *dai)
 {
-	struct snd_pcm_substream *substream =
-		rtd->pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
 	struct snd_card *card = rtd->card->snd_card;
 	struct aiu_fifo *fifo = dai->playback_dma_data;
 	size_t size = fifo->pcm->buffer_bytes_max;
 
-	snd_pcm_lib_preallocate_pages(substream,
-				      SNDRV_DMA_TYPE_DEV,
-				      card->dev, size, size);
+	snd_pcm_set_managed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
+				       card->dev, size, size);
 
 	return 0;
 }