ARM: hpe: Introduce the HPE GXP architecture

The GXP is the HPE BMC SoC that is used in the majority
of current generation HPE servers. Traditionally the asic will
last multiple generations of server before being replaced.

Info about SoC:

HPE GXP is the name of the HPE Soc. This SoC is used to implement many BMC
features at HPE. It supports ARMv7 architecture based on the Cortex A9
core. It is capable of using an AXI bus to whicha memory controller is
attached. It has multiple SPI interfaces to connect boot flash and BIOS
flash. It uses a 10/100/1000 MAC for network connectivity. It has multiple
i2c engines to drive connectivity with a host infrastructure. There
currently are no public specifications but this process is being worked.

Previously there was a requirement to reset the EHCI controller for the
asic to boot. This functionality has been moved to the u-boot
bootloader.

Signed-off-by: Nick Hawkins <nick.hawkins@hpe.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/Kconfig

@@ -620,6 +620,8 @@ source "arch/arm/mach-highbank/Kconfig"
 
 source "arch/arm/mach-hisi/Kconfig"
 
+source "arch/arm/mach-hpe/Kconfig"
+
 source "arch/arm/mach-imx/Kconfig"
 
 source "arch/arm/mach-integrator/Kconfig"

arch/arm/Makefile

@@ -179,6 +179,7 @@ machine-$(CONFIG_ARCH_FOOTBRIDGE)	+= footbridge
 machine-$(CONFIG_ARCH_GEMINI)		+= gemini
 machine-$(CONFIG_ARCH_HIGHBANK)		+= highbank
 machine-$(CONFIG_ARCH_HISI)		+= hisi
+machine-$(CONFIG_ARCH_HPE)		+= hpe
 machine-$(CONFIG_ARCH_INTEGRATOR)	+= integrator
 machine-$(CONFIG_ARCH_IOP32X)		+= iop32x
 machine-$(CONFIG_ARCH_IXP4XX)		+= ixp4xx

arch/arm/mach-hpe/Kconfig

@@ -0,0 +1,23 @@
+menuconfig ARCH_HPE
+	bool "HPE SoC support"
+	depends on ARCH_MULTI_V7
+	help
+	  This enables support for HPE ARM based BMC chips.
+if ARCH_HPE
+
+config ARCH_HPE_GXP
+	bool "HPE GXP SoC"
+	depends on ARCH_MULTI_V7
+	select ARM_VIC
+	select GENERIC_IRQ_CHIP
+	select CLKSRC_MMIO
+	help
+	  HPE GXP is the name of the HPE Soc. This SoC is used to implement many
+	  BMC features at HPE. It supports ARMv7 architecture based on the Cortex
+	  A9 core. It is capable of using an AXI bus to which a memory controller
+	  is attached. It has multiple SPI interfaces to connect boot flash and
+	  BIOS flash. It uses a 10/100/1000 MAC for network connectivity. It
+	  has multiple i2c engines to drive connectivity with a host
+	  infrastructure.
+
+endif

arch/arm/mach-hpe/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_ARCH_HPE_GXP) += gxp.o

arch/arm/mach-hpe/gxp.c

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2022 Hewlett-Packard Enterprise Development Company, L.P. */
+
+#include <linux/of_platform.h>
+#include <asm/mach/arch.h>
+
+static const char * const gxp_board_dt_compat[] = {
+	"hpe,gxp",
+	NULL,
+};
+
+DT_MACHINE_START(GXP_DT, "HPE GXP")
+	.dt_compat	= gxp_board_dt_compat,
+	.l2c_aux_val = 0,
+	.l2c_aux_mask = ~0,
+MACHINE_END