platform/x86/intel: Move intel_pmt from MFD to Auxiliary Bus

Intel Platform Monitoring Technology (PMT) support is indicated by presence
of an Intel defined PCIe DVSEC structure with a PMT ID. However DVSEC
structures may also be used by Intel to indicate support for other
capabilities unrelated to PMT.  The Out Of Band Management Services Module
(OOBMSM) is an example of a device that can have both PMT and non-PMT
capabilities. In order to support these capabilities it is necessary to
modify the intel_pmt driver to handle the creation of platform devices more
generically. To that end the following changes are made.

Convert the driver and child drivers from MFD to the Auxiliary Bus. This
architecture is more suitable anyway since the driver partitions a
multifunctional PCIe device. This also moves the driver out of the MFD
subsystem and into platform/x86/intel.

Before, devices were named by their capability (e.g. pmt_telemetry).
Instead, generically name them by their capability ID (e.g.
intel_extended_cap.2). This allows the IDs to be created automatically,
minimizing the code needed to support future capabilities. However, to
ensure that unsupported devices aren't created, use an allow list to
specify supported capabilities. Along these lines, rename the driver from
intel_pmt to intel_extended_caps to better reflect the purpose.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>

MAINTAINERS

@@ -9369,6 +9369,11 @@ S:	Supported
 F:	drivers/infiniband/hw/irdma/
 F:	include/uapi/rdma/irdma-abi.h
 
+INTEL EXTENDED CAPABILITIES DRIVER
+M:	"David E. Box" <david.e.box@linux.intel.com>
+S:	Supported
+F:	drivers/platform/x86/intel/extended_caps.*
+
 INTEL FRAMEBUFFER DRIVER (excluding 810 and 815)
 M:	Maik Broemme <mbroemme@libmpq.org>
 L:	linux-fbdev@vger.kernel.org
@@ -9578,10 +9583,9 @@ S:	Maintained
 F:	drivers/mfd/intel_soc_pmic*
 F:	include/linux/mfd/intel_soc_pmic*
 
-INTEL PMT DRIVER
+INTEL PMT DRIVERS
 M:	"David E. Box" <david.e.box@linux.intel.com>
-S:	Maintained
-F:	drivers/mfd/intel_pmt.c
+S:	Supported
 F:	drivers/platform/x86/intel/pmt/
 
 INTEL PRO/WIRELESS 2100, 2200BG, 2915ABG NETWORK CONNECTION SUPPORT

drivers/mfd/Kconfig

@@ -690,16 +690,6 @@ config MFD_INTEL_PMC_BXT
 	  Register and P-unit access. In addition this creates devices
 	  for iTCO watchdog and telemetry that are part of the PMC.
 
-config MFD_INTEL_PMT
-	tristate "Intel Platform Monitoring Technology (PMT) support"
-	depends on PCI
-	select MFD_CORE
-	help
-	  The Intel Platform Monitoring Technology (PMT) is an interface that
-	  provides access to hardware monitor registers. This driver supports
-	  Telemetry, Watcher, and Crashlog PMT capabilities/devices for
-	  platforms starting from Tiger Lake.
-
 config MFD_IPAQ_MICRO
 	bool "Atmel Micro ASIC (iPAQ h3100/h3600/h3700) Support"
 	depends on SA1100_H3100 || SA1100_H3600

drivers/mfd/Makefile

@@ -212,7 +212,6 @@ obj-$(CONFIG_MFD_INTEL_LPSS)	+= intel-lpss.o
 obj-$(CONFIG_MFD_INTEL_LPSS_PCI)	+= intel-lpss-pci.o
 obj-$(CONFIG_MFD_INTEL_LPSS_ACPI)	+= intel-lpss-acpi.o
 obj-$(CONFIG_MFD_INTEL_PMC_BXT)	+= intel_pmc_bxt.o
-obj-$(CONFIG_MFD_INTEL_PMT)	+= intel_pmt.o
 obj-$(CONFIG_MFD_PALMAS)	+= palmas.o
 obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o
 obj-$(CONFIG_MFD_NTXEC)		+= ntxec.o

drivers/platform/x86/intel/Kconfig

@@ -26,6 +26,17 @@ source "drivers/platform/x86/intel/speed_select_if/Kconfig"
 source "drivers/platform/x86/intel/telemetry/Kconfig"
 source "drivers/platform/x86/intel/wmi/Kconfig"
 
+config INTEL_EXTENDED_CAPS
+	tristate "Intel Extended Capabilities support"
+	depends on PCI
+	select AUXILIARY_BUS
+	help
+	  Adds support for feature drivers exposed using Intel PCIe VSEC and
+	  DVSEC.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called intel_extended_caps.
+
 config INTEL_HID_EVENT
 	tristate "Intel HID Event"
 	depends on ACPI

drivers/platform/x86/intel/Makefile

@@ -21,6 +21,8 @@ intel-vbtn-y				:= vbtn.o
 obj-$(CONFIG_INTEL_VBTN)		+= intel-vbtn.o
 
 # Intel miscellaneous drivers
+intel_extended_caps-y			:= extended_caps.o
+obj-$(CONFIG_INTEL_EXTENDED_CAPS)	+= intel_extended_caps.o
 intel_int0002_vgpio-y			:= int0002_vgpio.o
 obj-$(CONFIG_INTEL_INT0002_VGPIO)	+= intel_int0002_vgpio.o
 intel_oaktrail-y			:= oaktrail.o