i2c: bcm-kona: Introduce Broadcom I2C Driver

Introduce support for Broadcom Serial Controller (BSC) I2C bus found
in the Kona family of Mobile SoCs.  FIFO hardware is utilized but only
standard mode (100kHz), fast mode (400kHz), fast mode plus (1MHz), and
I2C high-speed (3.4 MHz) bus speeds are supported.
Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
[wsa: fixed Kconfig sorting, squashed broken out patches into one]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Documentation/devicetree/bindings/i2c/i2c-bcm-kona.txt

+Broadcom Kona Family I2C
+=========================
+
+This I2C controller is used in the following Broadcom SoCs:
+
+  BCM11130
+  BCM11140
+  BCM11351
+  BCM28145
+  BCM28155
+
+Required Properties
+-------------------
+- compatible: "brcm,bcm11351-i2c", "brcm,kona-i2c"
+- reg: Physical base address and length of controller registers
+- interrupts: The interrupt number used by the controller
+- clocks: clock specifier for the kona i2c external clock
+- clock-frequency: The I2C bus frequency in Hz
+- #address-cells: Should be <1>
+- #size-cells: Should be <0>
+
+Refer to clocks/clock-bindings.txt for generic clock consumer
+properties.
+
+Example:
+
+i2c@3e016000 {
+	compatible = "brcm,bcm11351-i2c","brcm,kona-i2c";
+	reg = <0x3e016000 0x80>;
+	interrupts = <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
+	clocks = <&bsc1_clk>;
+	clock-frequency = <400000>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+};

drivers/i2c/busses/Kconfig

@@ -346,6 +346,16 @@ config I2C_BCM2835
 	  This support is also available as a module.  If so, the module
 	  will be called i2c-bcm2835.
 
+config I2C_BCM_KONA
+	tristate "BCM Kona I2C adapter"
+	depends on ARCH_BCM_MOBILE
+	default y
+	help
+	  If you say yes to this option, support will be included for the
+	  I2C interface on the Broadcom Kona family of processors.
+
+	  If you do not need KONA I2C inteface, say N.
+
 config I2C_BLACKFIN_TWI
 	tristate "Blackfin TWI I2C support"
 	depends on BLACKFIN

drivers/i2c/busses/Makefile

@@ -89,6 +89,7 @@ obj-$(CONFIG_I2C_VIPERBOARD)	+= i2c-viperboard.o
 
 # Other I2C/SMBus bus drivers
 obj-$(CONFIG_I2C_ACORN)		+= i2c-acorn.o
+obj-$(CONFIG_I2C_BCM_KONA)	+= i2c-bcm-kona.o
 obj-$(CONFIG_I2C_ELEKTOR)	+= i2c-elektor.o
 obj-$(CONFIG_I2C_PCA_ISA)	+= i2c-pca-isa.o
 obj-$(CONFIG_I2C_SIBYTE)	+= i2c-sibyte.o