ASoC: add RT286 CODEC driver

This patch adds Realtek ALC286 codec driver.

ALC286 is a dual mode codec, which can run as HD-A or I2S mode.
It is controlled by HD-A verb commands via I2C protocol.
The following is the I/O difference between ALC286 and general I2S codecs.
1. A HD-A verb command contains three parts, NID, VID, and PID.
   And an I2S command contains only two parts: address and data.
2. Not only the register address is written, but the read command also
   includes the entire write command.
3. rt286 uses different registers for read and write the same bits.

We map verb command to regmap structure. However, we read most registers from
cache to prevent the asymmetry read/write issue in rt286.

Signed-off-by: Bard Liao <bardliao@realtek.com>
Signed-off-by: Gustaw Lewandowski <gustaw.lewandowski@intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

include/sound/rt286.h

@@ -0,0 +1,19 @@
+/*
+ * linux/sound/rt286.h -- Platform data for RT286
+ *
+ * Copyright 2013 Realtek Microelectronics
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __LINUX_SND_RT286_H
+#define __LINUX_SND_RT286_H
+
+struct rt286_platform_data {
+	bool cbj_en; /*combo jack enable*/
+	bool gpio2_en; /*GPIO2 enable*/
+};
+
+#endif

sound/soc/codecs/Kconfig

@@ -74,6 +74,7 @@ config SND_SOC_ALL_CODECS
 	select SND_SOC_PCM3008
 	select SND_SOC_PCM512x_I2C if I2C
 	select SND_SOC_PCM512x_SPI if SPI_MASTER
+	select SND_SOC_RT286 if I2C
 	select SND_SOC_RT5631 if I2C
 	select SND_SOC_RT5640 if I2C
 	select SND_SOC_RT5645 if I2C
@@ -449,6 +450,9 @@ config SND_SOC_RL6231
 	default m if SND_SOC_RT5645=m
 	default m if SND_SOC_RT5651=m
 
+config SND_SOC_RT286
+	tristate
+
 config SND_SOC_RT5631
 	tristate
 

sound/soc/codecs/Makefile

@@ -68,6 +68,7 @@ snd-soc-pcm512x-objs := pcm512x.o
 snd-soc-pcm512x-i2c-objs := pcm512x-i2c.o
 snd-soc-pcm512x-spi-objs := pcm512x-spi.o
 snd-soc-rl6231-objs := rl6231.o
+snd-soc-rt286-objs := rt286.o
 snd-soc-rt5631-objs := rt5631.o
 snd-soc-rt5640-objs := rt5640.o
 snd-soc-rt5645-objs := rt5645.o
@@ -233,6 +234,7 @@ obj-$(CONFIG_SND_SOC_PCM512x)	+= snd-soc-pcm512x.o
 obj-$(CONFIG_SND_SOC_PCM512x_I2C)	+= snd-soc-pcm512x-i2c.o
 obj-$(CONFIG_SND_SOC_PCM512x_SPI)	+= snd-soc-pcm512x-spi.o
 obj-$(CONFIG_SND_SOC_RL6231)	+= snd-soc-rl6231.o
+obj-$(CONFIG_SND_SOC_RT286)	+= snd-soc-rt286.o
 obj-$(CONFIG_SND_SOC_RT5631)	+= snd-soc-rt5631.o
 obj-$(CONFIG_SND_SOC_RT5640)	+= snd-soc-rt5640.o
 obj-$(CONFIG_SND_SOC_RT5645)	+= snd-soc-rt5645.o