ASoC: codecs: Add msm8916-wcd digital codec

msm8916-wcd codec is found in Qualcomm msm8916 and apq8016 processors.
This codec IP is split in to two parts(Digital & Analog).
Analog part is integrated in to PMIC PM8916 and the digital part is
integrated into Application processor. Data transfer between Analog and
Digital Die is done via a internal bus called PDM.

This patch adds support to Digital part of the Codec which is integrated
into Application Processor.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/qcom,msm8916-wcd-digital.txt

+msm8916 digital audio CODEC
+
+## Bindings for codec core in lpass:
+
+Required properties
+ - compatible = "qcom,msm8916-wcd-digital-codec";
+ - reg: address space for lpass codec.
+ - clocks: Handle to mclk and ahbclk
+ - clock-names: should be "mclk", "ahbix-clk".
+
+Example:
+
+audio-codec@771c000{
+	compatible = "qcom,msm8916-wcd-digital-codec";
+	reg = <0x0771c000 0x400>;
+	clocks = <&gcc GCC_ULTAUDIO_AHBFABRIC_IXFABRIC_CLK>,
+		 <&gcc GCC_CODEC_DIGCODEC_CLK>;
+	clock-names = "ahbix-clk", "mclk";
+	#sound-dai-cells = <1>;
+};

sound/soc/codecs/Kconfig

@@ -585,6 +585,9 @@ config SND_SOC_MSM8916_WCD_ANALOG
 	tristate "Qualcomm MSM8916 WCD Analog Codec"
 	depends on SPMI || COMPILE_TEST
 
+config SND_SOC_MSM8916_WCD_DIGITAL
+	tristate "Qualcomm MSM8916 WCD DIGITAL Codec"
+
 config SND_SOC_PCM1681
 	tristate "Texas Instruments PCM1681 CODEC"
 	depends on I2C

sound/soc/codecs/Makefile

@@ -87,6 +87,7 @@ snd-soc-max9860-objs := max9860.o
 snd-soc-mc13783-objs := mc13783.o
 snd-soc-ml26124-objs := ml26124.o
 snd-soc-msm8916-analog-objs := msm8916-wcd-analog.o
+snd-soc-msm8916-digital-objs := msm8916-wcd-digital.o
 snd-soc-nau8810-objs := nau8810.o
 snd-soc-nau8825-objs := nau8825.o
 snd-soc-hdmi-codec-objs := hdmi-codec.o
@@ -311,6 +312,7 @@ obj-$(CONFIG_SND_SOC_MAX9860)	+= snd-soc-max9860.o
 obj-$(CONFIG_SND_SOC_MC13783)	+= snd-soc-mc13783.o
 obj-$(CONFIG_SND_SOC_ML26124)	+= snd-soc-ml26124.o
 obj-$(CONFIG_SND_SOC_MSM8916_WCD_ANALOG) +=snd-soc-msm8916-analog.o
+obj-$(CONFIG_SND_SOC_MSM8916_WCD_DIGITAL) +=snd-soc-msm8916-digital.o
 obj-$(CONFIG_SND_SOC_NAU8810)   += snd-soc-nau8810.o
 obj-$(CONFIG_SND_SOC_NAU8825)   += snd-soc-nau8825.o
 obj-$(CONFIG_SND_SOC_HDMI_CODEC)	+= snd-soc-hdmi-codec.o