MIPS: generic: Add support for Ingenic SoCs

Add support for Ingenic SoCs in arch/mips/generic/.

The Kconfig changes are here to ensure that it is possible to compile
either a generic kernel that supports Ingenic SoCs, or a Ingenic-only
kernel, both using the same code base, to avoid duplicated code.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/generic/Kconfig

@@ -73,6 +73,12 @@ config FIT_IMAGE_FDT_OCELOT
 	  from Microsemi in the FIT kernel image.
 	  This requires u-boot on the platform.
 
+config BOARD_INGENIC
+	bool "Support boards based on Ingenic SoCs"
+	select MACH_INGENIC_GENERIC
+	help
+	  Enable support for boards based on Ingenic SoCs.
+
 config VIRT_BOARD_RANCHU
 	bool "Support Ranchu platform for Android emulator"
 	help

arch/mips/generic/Makefile

@@ -11,4 +11,5 @@ obj-y += proc.o
 obj-$(CONFIG_YAMON_DT_SHIM)		+= yamon-dt.o
 obj-$(CONFIG_LEGACY_BOARD_SEAD3)	+= board-sead3.o
 obj-$(CONFIG_LEGACY_BOARD_OCELOT)	+= board-ocelot.o
+obj-$(CONFIG_MACH_INGENIC)			+= board-ingenic.o
 obj-$(CONFIG_VIRT_BOARD_RANCHU)		+= board-ranchu.o

arch/mips/generic/Platform

@@ -8,7 +8,10 @@
 # option) any later version.
 #
 
+# Note: order matters, keep the asm/mach-generic include last.
+cflags-$(CONFIG_MACH_INGENIC_SOC)	+= -I$(srctree)/arch/mips/include/asm/mach-jz4740
 cflags-$(CONFIG_MIPS_GENERIC)	+= -I$(srctree)/arch/mips/include/asm/mach-generic
+
 load-$(CONFIG_MIPS_GENERIC)	+= 0xffffffff80100000
 zload-$(CONFIG_MIPS_GENERIC)	+= 0xffffffff81000000
 all-$(CONFIG_MIPS_GENERIC)	:= vmlinux.gz.itb

arch/mips/generic/board-ingenic.c

@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Support for Ingenic SoCs
+ *
+ * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
+ * Copyright (C) 2011, Maarten ter Huurne <maarten@treewalker.org>
+ * Copyright (C) 2020 Paul Cercueil <paul@crapouillou.net>
+ */
+
+#include <linux/of_address.h>
+#include <linux/of_fdt.h>
+#include <linux/pm.h>
+#include <linux/sizes.h>
+#include <linux/suspend.h>
+#include <linux/types.h>
+
+#include <asm/bootinfo.h>
+#include <asm/machine.h>
+#include <asm/reboot.h>
+
+static __init char *ingenic_get_system_type(unsigned long machtype)
+{
+	switch (machtype) {
+	case MACH_INGENIC_X1830:
+		return "X1830";
+	case MACH_INGENIC_X1000:
+		return "X1000";
+	case MACH_INGENIC_JZ4780:
+		return "JZ4780";
+	case MACH_INGENIC_JZ4770:
+		return "JZ4770";
+	case MACH_INGENIC_JZ4725B:
+		return "JZ4725B";
+	default:
+		return "JZ4740";
+	}
+}
+
+static __init const void *ingenic_fixup_fdt(const void *fdt, const void *match_data)
+{
+	/*
+	 * Old devicetree files for the qi,lb60 board did not have a /memory
+	 * node. Hardcode the memory info here.
+	 */
+	if (!fdt_node_check_compatible(fdt, 0, "qi,lb60") &&
+	    fdt_path_offset(fdt, "/memory") < 0)
+		early_init_dt_add_memory_arch(0, SZ_32M);
+
+	mips_machtype = (unsigned long)match_data;
+	system_type = ingenic_get_system_type(mips_machtype);
+
+	return fdt;
+}
+
+static const struct of_device_id ingenic_of_match[] __initconst = {
+	{ .compatible = "ingenic,jz4740", .data = (void *)MACH_INGENIC_JZ4740 },
+	{ .compatible = "ingenic,jz4725b", .data = (void *)MACH_INGENIC_JZ4725B },
+	{ .compatible = "ingenic,jz4770", .data = (void *)MACH_INGENIC_JZ4770 },
+	{ .compatible = "ingenic,jz4780", .data = (void *)MACH_INGENIC_JZ4780 },
+	{ .compatible = "ingenic,x1000", .data = (void *)MACH_INGENIC_X1000 },
+	{ .compatible = "ingenic,x1830", .data = (void *)MACH_INGENIC_X1830 },
+	{}
+};
+
+MIPS_MACHINE(ingenic) = {
+	.matches = ingenic_of_match,
+	.fixup_fdt = ingenic_fixup_fdt,
+};
+
+static void ingenic_wait_instr(void)
+{
+	__asm__(".set push;\n"
+		".set mips3;\n"
+		"wait;\n"
+		".set pop;\n"
+	);
+}
+
+static void ingenic_halt(void)
+{
+	for (;;)
+		ingenic_wait_instr();
+}
+
+static int __maybe_unused ingenic_pm_enter(suspend_state_t state)
+{
+	ingenic_wait_instr();
+
+	return 0;
+}
+
+static const struct platform_suspend_ops ingenic_pm_ops __maybe_unused = {
+	.valid = suspend_valid_only_mem,
+	.enter = ingenic_pm_enter,
+};
+
+static int __init ingenic_pm_init(void)
+{
+	if (boot_cpu_type() == CPU_XBURST) {
+		if (IS_ENABLED(CONFIG_PM_SLEEP))
+			suspend_set_ops(&ingenic_pm_ops);
+		_machine_halt = ingenic_halt;
+	}
+
+	return 0;
+
+}
+late_initcall(ingenic_pm_init);