i2c: Add GXP SoC I2C Controller

The GXP SoC supports 10 I2C engines. Each I2C engine is completely
independent and can function both as an I2C master and I2C slave. The
I2C master can operate in a multi master environment. The engines support
a scalable speed from 8kHZ to 1.5 Mhz.

Signed-off-by: Nick Hawkins <nick.hawkins@hpe.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/Kconfig

@@ -659,6 +659,13 @@ config I2C_GPIO_FAULT_INJECTOR
 	  faults to an I2C bus, so another bus master can be stress-tested.
 	  This is for debugging. If unsure, say 'no'.
 
+config I2C_GXP
+	tristate "GXP I2C Interface"
+	depends on ARCH_HPE_GXP || COMPILE_TEST
+	help
+	  This enables support for GXP I2C interface. The I2C engines can be
+	  either I2C master or I2C slaves.
+
 config I2C_HIGHLANDER
 	tristate "Highlander FPGA SMBus interface"
 	depends on SH_HIGHLANDER || COMPILE_TEST

drivers/i2c/busses/Makefile

@@ -128,6 +128,7 @@ obj-$(CONFIG_I2C_THUNDERX)	+= i2c-thunderx.o
 obj-$(CONFIG_I2C_XILINX)	+= i2c-xiic.o
 obj-$(CONFIG_I2C_XLP9XX)	+= i2c-xlp9xx.o
 obj-$(CONFIG_I2C_RCAR)		+= i2c-rcar.o
+obj-$(CONFIG_I2C_GXP)		+= i2c-gxp.o
 
 # External I2C/SMBus adapter drivers
 obj-$(CONFIG_I2C_DIOLAN_U2C)	+= i2c-diolan-u2c.o