misc: add FPC202 dual port controller driver

The TI FPC202 dual port controller serves as a low-speed signal aggregator
for common port types such as SFP, QSFP, Mini-SAS HD, and others.

It aggregates GPIO and I2C signals across two downstream ports, acting as
both a GPIO controller and an I2C address translator for up to two logical
devices per port.

Reviewed-by: Linus Walleij <[email protected]>
Tested-by: Tomi Valkeinen <[email protected]>
Signed-off-by: Romain Gantois <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Andi Shyti <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

Author: rgantois

MAINTAINERS

@@ -24211,6 +24211,7 @@ M:	Romain Gantois <[email protected]>
 L:	[email protected]
 S:	Maintained
 F:	Documentation/devicetree/bindings/misc/ti,fpc202.yaml
+F:	drivers/misc/ti_fpc202.c
 
 TI FPD-LINK DRIVERS
 M:	Tomi Valkeinen <[email protected]>

drivers/misc/Kconfig

@@ -114,6 +114,18 @@ config RPMB
 
 	  If unsure, select N.
 
+config TI_FPC202
+	tristate "TI FPC202 Dual Port Controller"
+	depends on I2C
+	select GPIOLIB
+	select I2C_ATR
+	help
+	  If you say yes here you get support for the Texas Instruments FPC202
+	  Dual Port Controller.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called fpc202.
+
 config TIFM_CORE
 	tristate "TI Flash Media interface support"
 	depends on PCI

drivers/misc/Makefile

@@ -12,6 +12,7 @@ obj-$(CONFIG_ATMEL_SSC)		+= atmel-ssc.o
 obj-$(CONFIG_DUMMY_IRQ)		+= dummy-irq.o
 obj-$(CONFIG_ICS932S401)	+= ics932s401.o
 obj-$(CONFIG_LKDTM)		+= lkdtm/
+obj-$(CONFIG_TI_FPC202)		+= ti_fpc202.o
 obj-$(CONFIG_TIFM_CORE)       	+= tifm_core.o
 obj-$(CONFIG_TIFM_7XX1)       	+= tifm_7xx1.o
 obj-$(CONFIG_PHANTOM)		+= phantom.o