x86, platform: Initial support for sta2x11 I/O hub

The "ConneXt" sta2x11 I/O Hub is a bridge from PCIe to AMBA, and is
used as main chipset in some Atom boards.  The set of peripherals it
exports live in an AMBA bus internal to the chip, so a custom
remapping of addresses is needed. This is implemented by fixup calls
for the PCI deivices, based on CONFIG_X86_DEV_DMA_OPS and
CONFIG_X86_DMA_REMAP .

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Link: http://lkml.kernel.org/r/ddca670ca8180e52d49b3fe642742ddd23ab2cb2.1333560789.git.rubini@gnudd.com
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/Kconfig

@@ -329,6 +329,7 @@ config X86_EXTENDED_PLATFORM
 		NUMAQ (IBM/Sequent)
 		RDC R-321x SoC
 		SGI 320/540 (Visual Workstation)
+		STA2X11-based (e.g. Northville)
 		Summit/EXA (IBM x440)
 		Unisys ES7000 IA32 series
 		Moorestown MID devices
@@ -461,10 +462,10 @@ config X86_32_NON_STANDARD
 	depends on X86_32 && SMP
 	depends on X86_EXTENDED_PLATFORM
 	---help---
-	  This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
-	  subarchitectures.  It is intended for a generic binary kernel.
-	  if you select them all, kernel will probe it one by one. and will
-	  fallback to default.
+	  This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
+	  STA2X11, default subarchitectures.  It is intended for a generic
+	  binary kernel. If you select them all, kernel will probe it
+	  one by one and will fallback to default.
 
 # Alphabetically sorted list of Non standard 32 bit platforms
 
@@ -504,6 +505,22 @@ config X86_VISWS
 	  A kernel compiled for the Visual Workstation will run on general
 	  PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 
+config STA2X11
+	bool "STA2X11 Companion Chip Support"
+	depends on X86_32_NON_STANDARD && PCI
+	select X86_DEV_DMA_OPS
+	select X86_DMA_REMAP
+	select SWIOTLB
+	select MFD_STA2X11
+	select ARCH_REQUIRE_GPIOLIB
+	default n
+	---help---
+	  This adds support for boards based on the STA2X11 IO-Hub,
+	  a.k.a. "ConneXt". The chip is used in place of the standard
+	  PC chipset, so all "standard" peripherals are missing. If this
+	  option is selected the kernel will still be able to boot on
+	  standard PC machines.
+
 config X86_SUMMIT
 	bool "Summit/EXA (IBM x440)"
 	depends on X86_32_NON_STANDARD
@@ -2218,10 +2235,11 @@ config HAVE_TEXT_POKE_SMP
 
 config X86_DEV_DMA_OPS
 	bool
-	depends on X86_64
+	depends on X86_64 || STA2X11
 
 config X86_DMA_REMAP
 	bool
+	depends on STA2X11
 
 source "net/Kconfig"
 

arch/x86/pci/Makefile

@@ -11,6 +11,8 @@ obj-$(CONFIG_X86_INTEL_CE)      += ce4100.o
 obj-$(CONFIG_ACPI)		+= acpi.o
 obj-y				+= legacy.o irq.o
 
+obj-$(CONFIG_STA2X11)           += sta2x11-fixup.o
+
 obj-$(CONFIG_X86_VISWS)		+= visws.o
 
 obj-$(CONFIG_X86_NUMAQ)		+= numaq_32.o