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>

4 files changed, 97 insertions, 0 deletions

diff --git a/sound/soc/omap/Kconfig b/sound/soc/omap/Kconfig
index 9d20c9b94477..2576fc92bff7 100644
--- a/sound/soc/omap/Kconfig
+++ b/sound/soc/omap/Kconfig
@@ -2,6 +2,12 @@ config SND_OMAP_SOC
         tristate "SoC Audio for the Texas Instruments OMAP chips"
         depends on (ARCH_OMAP && DMA_OMAP) || (ARM && COMPILE_TEST)
         select SND_DMAENGINE_PCM
+        select SND_SDMA_SOC
+
+config SND_SDMA_SOC
+        tristate "SoC Audio for Texas Instruments chips using sDMA"
+        depends on DMA_OMAP
+        select SND_SOC_GENERIC_DMAENGINE_PCM
 
 config SND_OMAP_SOC_DMIC
         tristate
diff --git a/sound/soc/omap/Makefile b/sound/soc/omap/Makefile
index a6785dc4fc90..0619a5b3bd9f 100644
--- a/sound/soc/omap/Makefile
+++ b/sound/soc/omap/Makefile
@@ -1,12 +1,14 @@
 # SPDX-License-Identifier: GPL-2.0
 # OMAP Platform Support
 snd-soc-omap-objs := omap-pcm.o
+snd-soc-sdma-objs := sdma-pcm.o
 snd-soc-omap-dmic-objs := omap-dmic.o
 snd-soc-omap-mcbsp-objs := omap-mcbsp.o mcbsp.o
 snd-soc-omap-mcpdm-objs := omap-mcpdm.o
 snd-soc-omap-hdmi-audio-objs := omap-hdmi-audio.o
 
 obj-$(CONFIG_SND_OMAP_SOC) += snd-soc-omap.o
+obj-$(CONFIG_SND_SDMA_SOC) += snd-soc-sdma.o
 obj-$(CONFIG_SND_OMAP_SOC_DMIC) += snd-soc-omap-dmic.o
 obj-$(CONFIG_SND_OMAP_SOC_MCBSP) += snd-soc-omap-mcbsp.o
 obj-$(CONFIG_SND_OMAP_SOC_MCPDM) += snd-soc-omap-mcpdm.o
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);
diff --git a/sound/soc/omap/sdma-pcm.h b/sound/soc/omap/sdma-pcm.h
new file mode 100644
index 000000000000..34a7f90b2587
--- /dev/null
+++ b/sound/soc/omap/sdma-pcm.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com
+ *  Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
+ */
+
+#ifndef __SDMA_PCM_H__
+#define __SDMA_PCM_H__
+
+#if IS_ENABLED(CONFIG_SND_SDMA_SOC)
+int sdma_pcm_platform_register(struct device *dev,
+                               char *txdmachan, char *rxdmachan);
+#else
+static inline int sdma_pcm_platform_register(struct device *dev,
+                                             char *txdmachan, char *rxdmachan)
+{
+        return -ENODEV;
+}
+#endif /* CONFIG_SND_SDMA_SOC */
+
+#endif /* __SDMA_PCM_H__ */