ASoC: atmel: mchp-pdmc: add PDMC driver

The Pulse Density Microphone Controller (PDMC) interfaces up to 4 digital
microphones having Pulse Density Modulated (PDM) outputs. It generates a
single clock line and samples 1 or 2 data lines. The signal path includes
an audio grade programmable decimation filter and outputs 24-bit audio
words on the APB bus.

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Link: https://lore.kernel.org/r/20220307122202.2251639-4-codrin.ciubotariu@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/atmel/Kconfig

@@ -160,4 +160,20 @@ config SND_MCHP_SOC_SPDIFRX
 
 	  This S/PDIF RX driver is compliant with IEC-60958 standard and
 	  includes programmable User Data and Channel Status fields.
+
+config SND_MCHP_SOC_PDMC
+	tristate "Microchip ASoC driver for boards using PDMC"
+	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 ASoC PDMC driver on the
+	  following Microchip platforms:
+	  - sama7g5
+
+	  The Pulse Density Microphone Controller (PDMC) interfaces up to 4 digital
+	  microphones PDM outputs. It generates a single clock line and samples 1 or
+	  2 data lines. The signal path includes an audio grade programmable
+	  decimation filter and outputs 24-bit audio words.
+
 endif

sound/soc/atmel/Makefile

@@ -7,6 +7,7 @@ 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
 snd-soc-mchp-spdifrx-objs := mchp-spdifrx.o
+snd-soc-mchp-pdmc-objs := mchp-pdmc.o
 
 # pdc and dma need to both be built-in if any user of
 # ssc is built-in.
@@ -21,6 +22,7 @@ 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-$(CONFIG_SND_MCHP_SOC_SPDIFTX) += snd-soc-mchp-spdiftx.o
 obj-$(CONFIG_SND_MCHP_SOC_SPDIFRX) += snd-soc-mchp-spdifrx.o
+obj-$(CONFIG_SND_MCHP_SOC_PDMC) += snd-soc-mchp-pdmc.o
 
 # AT91 Machine Support
 snd-soc-sam9g20-wm8731-objs := sam9g20_wm8731.o