PCI: aspeed: Add ASPEED PCIe RC driver

Introduce PCIe Root Complex driver for ASPEED SoCs. Support RC
initialization, reset, clock, IRQ domain, and MSI domain setup. Implement
platform-specific setup and register configuration for ASPEED. And provide
PCI config space read/write and INTx/MSI interrupt handling.

Signed-off-by: Jacky Chou <jacky_chou@aspeedtech.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20251216-upstream_pcie_rc-v7-6-4aeb0f53c4ce@aspeedtech.com

drivers/pci/controller/Kconfig

@@ -58,6 +58,22 @@ config PCI_VERSATILE
 	bool "ARM Versatile PB PCI controller"
 	depends on ARCH_VERSATILE || COMPILE_TEST
 
+config PCIE_ASPEED
+	bool "ASPEED PCIe controller"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	depends on OF
+	depends on PCI_MSI
+	select IRQ_MSI_LIB
+	help
+	  Enable this option to support the PCIe controller found on ASPEED
+	  SoCs.
+
+	  This driver provides initialization and management for PCIe
+	  Root Complex functionality, including INTx and MSI support.
+
+	  Select Y if your platform uses an ASPEED SoC and requires PCIe
+	  connectivity.
+
 config PCIE_BRCMSTB
 	tristate "Broadcom Brcmstb PCIe controller"
 	depends on ARCH_BRCMSTB || ARCH_BCM2835 || ARCH_BCMBCA || \

drivers/pci/controller/Makefile

@@ -40,6 +40,7 @@ obj-$(CONFIG_PCI_LOONGSON) += pci-loongson.o
 obj-$(CONFIG_PCIE_HISI_ERR) += pcie-hisi-error.o
 obj-$(CONFIG_PCIE_APPLE) += pcie-apple.o
 obj-$(CONFIG_PCIE_MT7621) += pcie-mt7621.o
+obj-$(CONFIG_PCIE_ASPEED) += pcie-aspeed.o
 
 # pcie-hisi.o quirks are needed even without CONFIG_PCIE_DW
 obj-y				+= dwc/