ASoC: mchp-spdiftx: add driver for S/PDIF TX Controller

The new SPDIF TX controller is a serial port compliant with the IEC-
60958 standard. It also supports programmable User Data and Channel
Status fields.

This IP is embedded in Microchip's sama7g5 SoC.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Link: https://lore.kernel.org/r/20200909145348.367033-2-codrin.ciubotariu@microchip.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/atmel/Kconfig

@@ -132,4 +132,16 @@ config SND_MCHP_SOC_I2S_MCC
 	  and supports a Time Division Multiplexed (TDM) interface with
 	  external multi-channel audio codecs.
 
+config SND_MCHP_SOC_SPDIFTX
+	tristate "Microchip ASoC driver for boards using S/PDIF TX"
+	depends on OF && (ARCH_AT91 || COMPILE_TEST)
+	select SND_SOC_GENERIC_DMAENGINE_PCM
+	select REGMAP_MMIO
+	help
+	  Say Y or M if you want to add support for Microchip S/PDIF TX ASoc
+	  driver on the following Microchip platforms:
+	  - sama7g5
+
+	  This S/PDIF TX driver is compliant with IEC-60958 standard and
+	  includes programable User Data and Channel Status fields.
 endif

sound/soc/atmel/Makefile

@@ -5,6 +5,7 @@ snd-soc-atmel-pcm-dma-objs := atmel-pcm-dma.o
 snd-soc-atmel_ssc_dai-objs := atmel_ssc_dai.o
 snd-soc-atmel-i2s-objs := atmel-i2s.o
 snd-soc-mchp-i2s-mcc-objs := mchp-i2s-mcc.o
+snd-soc-mchp-spdiftx-objs := mchp-spdiftx.o
 
 # pdc and dma need to both be built-in if any user of
 # ssc is built-in.
@@ -17,6 +18,7 @@ endif
 obj-$(CONFIG_SND_ATMEL_SOC_SSC) += snd-soc-atmel_ssc_dai.o
 obj-$(CONFIG_SND_ATMEL_SOC_I2S) += snd-soc-atmel-i2s.o
 obj-$(CONFIG_SND_MCHP_SOC_I2S_MCC) += snd-soc-mchp-i2s-mcc.o
+obj-$(CONFIG_SND_MCHP_SOC_SPDIFTX) += snd-soc-mchp-spdiftx.o
 
 # AT91 Machine Support
 snd-soc-sam9g20-wm8731-objs := sam9g20_wm8731.o