PCI: spear: Add PCIe driver for ST Microelectronics SPEAr13xx

ARM based ST Microelectronics's SPEAr1310 and SPEAr1340 SOCs have onchip
designware PCIe controller. To make that usable, this patch adds a wrapper
driver based on existing designware driver.

Adds bindings for this new driver and update MAINTAINERS as well.

Cc: linux-pci@vger.kernel.org
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Pratyush Anand <pratyush.anand@st.com>
Signed-off-by: Mohit Kumar <mohit.kumar@st.com>
[viresh: fixed logs/cclist/checkpatch warnings, broken into smaller patches]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Documentation/devicetree/bindings/pci/spear13xx-pcie.txt

+SPEAr13XX PCIe DT detail:
+================================
+
+SPEAr13XX uses synopsis designware PCIe controller and ST MiPHY as phy
+controller.
+
+Required properties:
+- compatible : should be "st,spear1340-pcie", "snps,dw-pcie".
+- phys		    : phandle to phy node associated with pcie controller
+- phy-names	    : must be "pcie-phy"
+- All other definitions as per generic PCI bindings
+
+ Optional properties:
+- st,pcie-is-gen1 indicates that forced gen1 initialization is needed.

MAINTAINERS

@@ -6820,6 +6820,12 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/pci/host-generic-pci.txt
 F:	drivers/pci/host/pci-host-generic.c
 
+PCIE DRIVER FOR ST SPEAR13XX
+M:	Mohit Kumar <mohit.kumar@st.com>
+L:	linux-pci@vger.kernel.org
+S:	Maintained
+F:	drivers/pci/host/*spear*
+
 PCMCIA SUBSYSTEM
 P:	Linux PCMCIA Team
 L:	linux-pcmcia@lists.infradead.org

drivers/pci/host/Kconfig

@@ -46,4 +46,12 @@ config PCI_HOST_GENERIC
 	  Say Y here if you want to support a simple generic PCI host
 	  controller, such as the one emulated by kvmtool.
 
+config PCIE_SPEAR13XX
+	tristate "STMicroelectronics SPEAr PCIe controller"
+	depends on ARCH_SPEAR13XX
+	select PCIEPORTBUS
+	select PCIE_DW
+	help
+	  Say Y here if you want PCIe support on SPEAr13XX SoCs.
+
 endmenu

drivers/pci/host/Makefile

@@ -6,3 +6,4 @@ obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o
 obj-$(CONFIG_PCI_RCAR_GEN2) += pci-rcar-gen2.o
 obj-$(CONFIG_PCI_RCAR_GEN2_PCIE) += pcie-rcar.o
 obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
+obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o