ASoC: sprd: Add Spreadtrum audio DMA platfrom driver

The Spreadtrum DMA engine uses the link-list mode to support audio playback
or capture, thus this patch adds audio DMA platform support for CPU DAI to
trigger DMA link-list transfer.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/Kconfig

@@ -64,6 +64,7 @@ source "sound/soc/samsung/Kconfig"
 source "sound/soc/sh/Kconfig"
 source "sound/soc/sirf/Kconfig"
 source "sound/soc/spear/Kconfig"
+source "sound/soc/sprd/Kconfig"
 source "sound/soc/sti/Kconfig"
 source "sound/soc/stm/Kconfig"
 source "sound/soc/sunxi/Kconfig"

sound/soc/Makefile

@@ -48,6 +48,7 @@ obj-$(CONFIG_SND_SOC)	+= samsung/
 obj-$(CONFIG_SND_SOC)	+= sh/
 obj-$(CONFIG_SND_SOC)	+= sirf/
 obj-$(CONFIG_SND_SOC)	+= spear/
+obj-$(CONFIG_SND_SOC)	+= sprd/
 obj-$(CONFIG_SND_SOC)	+= sti/
 obj-$(CONFIG_SND_SOC)	+= stm/
 obj-$(CONFIG_SND_SOC)	+= sunxi/

sound/soc/sprd/Kconfig

+config SND_SOC_SPRD
+	tristate "SoC Audio for the Spreadtrum SoC chips"
+	depends on ARCH_SPRD || COMPILE_TEST
+	help
+	  Say Y or M if you want to add support for codecs attached to
+	  the Spreadtrum SoCs' Audio interfaces.

sound/soc/sprd/Makefile

+# SPDX-License-Identifier: GPL-2.0
+# Spreadtrum Audio Support
+
+obj-$(CONFIG_SND_SOC_SPRD)	+= sprd-pcm-dma.o

sound/soc/sprd/sprd-pcm-dma.h

+// SPDX-License-Identifier: GPL-2.0
+
+#ifndef __SPRD_PCM_DMA_H
+#define __SPRD_PCM_DMA_H
+
+#define SPRD_PCM_CHANNEL_MAX	2
+
+struct sprd_pcm_dma_params {
+	dma_addr_t dev_phys[SPRD_PCM_CHANNEL_MAX];
+	u32 datawidth[SPRD_PCM_CHANNEL_MAX];
+	u32 fragment_len[SPRD_PCM_CHANNEL_MAX];
+	const char *chan_name[SPRD_PCM_CHANNEL_MAX];
+};
+
+#endif /* __SPRD_PCM_DMA_H */