ASoC: omap: Introduce the generic_dmaengine_pcm based sdma-pcm

With the generic dmaengine_pcm support the omap-cpm can be replaced with a
much smaller wrapper.

CPU DAI drivers can use the:
int sdma_pcm_platform_register(struct device *dev,
			       char *txdmachan, char *rxdmachan);

To register the platform driver, txdmachan/rxdmachan is only needed to be
provided if the DMA channel names are not standard tx/rx, like in case of
McPDM, or the DAI is only capable of one audio direction (DMIC, HDMI).

This patch only introduces the source file and changes to the
Kconfig/Makefile, but does not change any of the DAI drivers to use it.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 68 insertions, 0 deletions

diff --git a/sound/soc/omap/sdma-pcm.c b/sound/soc/omap/sdma-pcm.c
new file mode 100644
index 000000000000..f7b2b5b69d27
--- /dev/null
+++ b/sound/soc/omap/sdma-pcm.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com
+ *  Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
+ */
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/dmaengine_pcm.h>
+#include <linux/omap-dma.h>
+
+#include "sdma-pcm.h"
+
+static const struct snd_pcm_hardware sdma_pcm_hardware = {
+	.info			= SNDRV_PCM_INFO_MMAP |
+				  SNDRV_PCM_INFO_MMAP_VALID |
+				  SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME |
+				  SNDRV_PCM_INFO_NO_PERIOD_WAKEUP |
+				  SNDRV_PCM_INFO_INTERLEAVED,
+	.period_bytes_min	= 32,
+	.period_bytes_max	= 64 * 1024,
+	.buffer_bytes_max	= 128 * 1024,
+	.periods_min		= 2,
+	.periods_max		= 255,
+};
+
+static const struct snd_dmaengine_pcm_config sdma_dmaengine_pcm_config = {
+	.pcm_hardware = &sdma_pcm_hardware,
+	.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
+	.compat_filter_fn = omap_dma_filter_fn,
+	.prealloc_buffer_size = 128 * 1024,
+};
+
+int sdma_pcm_platform_register(struct device *dev,
+			       char *txdmachan, char *rxdmachan)
+{
+	struct snd_dmaengine_pcm_config *config;
+	unsigned int flags = SND_DMAENGINE_PCM_FLAG_COMPAT;
+
+	/* Standard names for the directions: 'tx' and 'rx' */
+	if (!txdmachan && !rxdmachan)
+		return devm_snd_dmaengine_pcm_register(dev,
+						&sdma_dmaengine_pcm_config,
+						flags);
+
+	config = devm_kzalloc(dev, sizeof(*config), GFP_KERNEL);
+	if (!config)
+		return -ENOMEM;
+
+	*config = sdma_dmaengine_pcm_config;
+
+	if (!txdmachan || !rxdmachan) {
+		/* One direction only PCM */
+		flags |= SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX;
+		if (!txdmachan) {
+			txdmachan = rxdmachan;
+			rxdmachan = NULL;
+		}
+	}
+
+	config->chan_names[0] = txdmachan;
+	config->chan_names[1] = rxdmachan;
+
+	return devm_snd_dmaengine_pcm_register(dev, config, flags);
+}
+EXPORT_SYMBOL_GPL(sdma_pcm_platform_register);