ASoC: codecs: wcd: add multi button Headset detection support

Most new Qualcomm WCD codecs support MBHC(Multi Button Headset Control) via ADC.

This patchset adds support to Common parts of this MBHC support so that
WCD codecs need not duplicate them. To do that codec exposes set of
register fields and callbacks to this common driver to control it.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210604115230.23259-3-srinivas.kandagatla@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/Kconfig

@@ -1536,6 +1536,9 @@ config SND_SOC_WCD9335
 	  Qualcomm Technologies, Inc. (QTI) multimedia solutions,
 	  including the MSM8996, MSM8976, and MSM8956 chipsets.
 
+config SND_SOC_WCD_MBHC
+	tristate
+
 config SND_SOC_WCD934X
 	tristate "WCD9340/WCD9341 Codec"
 	depends on COMMON_CLK

sound/soc/codecs/Makefile

@@ -251,6 +251,7 @@ snd-soc-twl6040-objs := twl6040.o
 snd-soc-uda1334-objs := uda1334.o
 snd-soc-uda134x-objs := uda134x.o
 snd-soc-uda1380-objs := uda1380.o
+snd-soc-wcd-mbhc-objs := wcd-mbhc-v2.o
 snd-soc-wcd9335-objs := wcd-clsh-v2.o wcd9335.o
 snd-soc-wcd934x-objs := wcd-clsh-v2.o wcd934x.o
 snd-soc-wl1273-objs := wl1273.o
@@ -574,6 +575,7 @@ obj-$(CONFIG_SND_SOC_TWL6040)	+= snd-soc-twl6040.o
 obj-$(CONFIG_SND_SOC_UDA1334)	+= snd-soc-uda1334.o
 obj-$(CONFIG_SND_SOC_UDA134X)	+= snd-soc-uda134x.o
 obj-$(CONFIG_SND_SOC_UDA1380)	+= snd-soc-uda1380.o
+obj-$(CONFIG_SND_SOC_WCD_MBHC)	+= snd-soc-wcd-mbhc.o
 obj-$(CONFIG_SND_SOC_WCD9335)	+= snd-soc-wcd9335.o
 obj-$(CONFIG_SND_SOC_WCD934X)	+= snd-soc-wcd934x.o
 obj-$(CONFIG_SND_SOC_WL1273)	+= snd-soc-wl1273.o