i2c: add support for Socionext SynQuacer I2C controller

This is a cleaned up version of the I2C controller driver for
the Fujitsu F_I2C IP, which was never supported upstream, and
has now been incorporated into the Socionext SynQuacer SoC.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
[wsa: updated MAINTAINERS entry and removed two empty lines]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

MAINTAINERS

@@ -12816,6 +12816,13 @@ F:	include/media/soc*
 F:	drivers/media/i2c/soc_camera/
 F:	drivers/media/platform/soc_camera/
 
+SOCIONEXT SYNQUACER I2C DRIVER
+M:	Ard Biesheuvel <ard.biesheuvel@linaro.org>
+L:	linux-i2c@vger.kernel.org
+S:	Maintained
+F:	drivers/i2c/busses/i2c-synquacer.c
+F:	Documentation/devicetree/bindings/i2c/i2c-synquacer.txt
+
 SOCIONEXT UNIPHIER SOUND DRIVER
 M:	Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>
 L:	alsa-devel@alsa-project.org (moderated for non-subscribers)

drivers/i2c/busses/Kconfig

@@ -997,6 +997,16 @@ config I2C_SUN6I_P2WI
 	  This interface is used to connect to specific PMIC devices (like the
 	  AXP221).
 
+config I2C_SYNQUACER
+	tristate "Socionext SynQuacer I2C controller"
+	depends on ARCH_SYNQUACER || COMPILE_TEST
+	help
+	  Say Y here to include support for the I2C controller used in some
+	  Fujitsu and Socionext SoCs.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called i2c-synquacer.
+
 config I2C_TEGRA
 	tristate "NVIDIA Tegra internal I2C controller"
 	depends on ARCH_TEGRA

drivers/i2c/busses/Makefile

@@ -98,6 +98,7 @@ obj-$(CONFIG_I2C_STM32F4)	+= i2c-stm32f4.o
 obj-$(CONFIG_I2C_STM32F7)	+= i2c-stm32f7.o
 obj-$(CONFIG_I2C_STU300)	+= i2c-stu300.o
 obj-$(CONFIG_I2C_SUN6I_P2WI)	+= i2c-sun6i-p2wi.o
+obj-$(CONFIG_I2C_SYNQUACER)	+= i2c-synquacer.o
 obj-$(CONFIG_I2C_TEGRA)		+= i2c-tegra.o
 obj-$(CONFIG_I2C_TEGRA_BPMP)	+= i2c-tegra-bpmp.o
 obj-$(CONFIG_I2C_UNIPHIER)	+= i2c-uniphier.o