mikroBUS driver for add-on boards on mikrobus ports

The mikrobus driver is updated to add mikrobus ports from device-tree
overlays, the debug interfaces for adding mikrobus ports through sysFS
is removed, and the driver considers the extended usage of mikrobus
port pins from their standard purpose, for example an SHT15 add-on
board will need the I2C pins to be configured as GPIOs for the
corresponding driver(drivers/hwmon/sht15.c) to work correctly
to consider cases like these the mikrobus driver supports setting
the pinmux states and can consider each Pin of the mikrobus port
as GPIO if required.

 The manifests for supported 110 add-on boards are available here:
 https://github.com/vaishnav98/manifesto/tree/mikrobusv3

Signed-off-by: Vaishnav M A <vaishnav@beagleboard.org>

MAINTAINERS

@@ -11543,6 +11543,12 @@ M:	Oliver Neukum <oliver@neukum.org>
 S:	Maintained
 F:	drivers/usb/image/microtek.*
 
+MIKROBUS ADDON BOARD DRIVER
+M:	Vaishnav M A <vaishnav@beagleboard.org>
+S:	Maintained
+W:	https://elinux.org/Mikrobus
+F:	drivers/misc/mikrobus/
+
 MIPS
 M:	Thomas Bogendoerfer <tsbogend@alpha.franken.de>
 L:	linux-mips@vger.kernel.org

drivers/misc/Kconfig

@@ -472,4 +472,5 @@ source "drivers/misc/ocxl/Kconfig"
 source "drivers/misc/cardreader/Kconfig"
 source "drivers/misc/habanalabs/Kconfig"
 source "drivers/misc/uacce/Kconfig"
+source "drivers/misc/mikrobus/Kconfig"
 endmenu

drivers/misc/Makefile

@@ -40,6 +40,7 @@ obj-$(CONFIG_VMWARE_BALLOON)	+= vmw_balloon.o
 obj-$(CONFIG_PCH_PHUB)		+= pch_phub.o
 obj-y				+= ti-st/
 obj-y				+= lis3lv02d/
+obj-y				+= mikrobus/
 obj-$(CONFIG_ALTERA_STAPL)	+=altera-stapl/
 obj-$(CONFIG_INTEL_MEI)		+= mei/
 obj-$(CONFIG_VMWARE_VMCI)	+= vmw_vmci/

drivers/misc/mikrobus/Kconfig

@@ -0,0 +1,16 @@
+menuconfig MIKROBUS
+	tristate "Module for instantiating devices on mikroBUS ports"
+	help
+	  This option enables the mikroBUS driver. mikroBUS is an add-on
+	  board socket standard that offers maximum expandability with
+	  the smallest number of pins. The mikroBUS driver instantiates
+	  devices on a mikroBUS port described by identifying data present
+	  in an add-on board resident EEPROM, more details on the mikroBUS
+	  driver support and discussion can be found in this eLinux wiki :
+	  elinux.org/Mikrobus
+
+
+	  Say Y here to enable support for this driver.
+
+	  To compile this code as a module, chose M here: the module
+	  will be called mikrobus.ko

drivers/misc/mikrobus/Makefile

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+# mikroBUS Core
+
+mikrobus-y :=	mikrobus_core.o	mikrobus_manifest.o
+mikrobus_port-y :=	mikrobus_port.o
+obj-$(CONFIG_MIKROBUS) += mikrobus.o
+obj-$(CONFIG_MIKROBUS) += mikrobus_port.o