[PATCH 2/6] mips: Add N64 machine type

[Lauri Kasanen <cand@gmx.com>]

Signed-off-by: Lauri Kasanen <cand@gmx.com>
---
 arch/mips/Kbuild.platforms           |  1 +
 arch/mips/Kconfig                    | 12 ++++++++
 arch/mips/include/asm/mach-n64/irq.h |  9 ++++++
 arch/mips/include/asm/n64/irq.h      | 26 ++++++++++++++++
 arch/mips/n64/Makefile               |  6 ++++
 arch/mips/n64/Platform               |  7 +++++
 arch/mips/n64/init.c                 | 59 ++++++++++++++++++++++++++++++++++++
 arch/mips/n64/irq.c                  | 34 +++++++++++++++++++++
 8 files changed, 154 insertions(+)
 create mode 100644 arch/mips/include/asm/mach-n64/irq.h
 create mode 100644 arch/mips/include/asm/n64/irq.h
 create mode 100644 arch/mips/n64/Makefile
 create mode 100644 arch/mips/n64/Platform
 create mode 100644 arch/mips/n64/init.c
 create mode 100644 arch/mips/n64/irq.c

diff --git a/arch/mips/Kbuild.platforms b/arch/mips/Kbuild.platforms
index 5483e38..3e39590 100644
--- a/arch/mips/Kbuild.platforms
+++ b/arch/mips/Kbuild.platforms
@@ -18,6 +18,7 @@ platform-$(CONFIG_MACH_LOONGSON2EF)	+= loongson2ef/
 platform-$(CONFIG_MACH_LOONGSON32)	+= loongson32/
 platform-$(CONFIG_MACH_LOONGSON64)	+= loongson64/
 platform-$(CONFIG_MIPS_MALTA)		+= mti-malta/
+platform-$(CONFIG_MIPS_N64)		+= n64/
 platform-$(CONFIG_NLM_COMMON)		+= netlogic/
 platform-$(CONFIG_PIC32MZDA)		+= pic32/
 platform-$(CONFIG_MACH_PISTACHIO)	+= pistachio/
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 4b52588..2922bb6 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -605,6 +605,18 @@ config MACH_VR41XX
 	select SYS_SUPPORTS_MIPS16
 	select GPIOLIB

+config MIPS_N64
+	bool "Nintendo 64 console"
+	select CEVT_R4K
+	select CSRC_R4K
+	select SYS_HAS_CPU_R4300
+	select SYS_SUPPORTS_BIG_ENDIAN
+	select SYS_SUPPORTS_ZBOOT
+	select SYS_SUPPORTS_32BIT_KERNEL
+	select SYS_SUPPORTS_64BIT_KERNEL
+	select DMA_NONCOHERENT
+	select IRQ_MIPS_CPU
+
 config RALINK
 	bool "Ralink based machines"
 	select CEVT_R4K
diff --git a/arch/mips/include/asm/mach-n64/irq.h b/arch/mips/include/asm/mach-n64/irq.h
new file mode 100644
index 0000000..4d4a1ea
--- /dev/null
+++ b/arch/mips/include/asm/mach-n64/irq.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_MACH_N64_IRQ_H
+#define __ASM_MACH_N64_IRQ_H
+
+#include <asm/n64/irq.h> /* for MIPS_CPU_IRQ_BASE */
+
+#include <asm/mach-generic/irq.h>
+
+#endif /* __ASM_MACH_N64_IRQ_H */
diff --git a/arch/mips/include/asm/n64/irq.h b/arch/mips/include/asm/n64/irq.h
new file mode 100644
index 0000000..00f89ca
--- /dev/null
+++ b/arch/mips/include/asm/n64/irq.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Interrupt numbers for N64
+ *
+ * Copyright (C) 2020 Lauri Kasanen
+ */
+#ifndef __N64_IRQ_H
+#define __N64_IRQ_H
+
+#define NR_IRQS 8
+
+/*
+ * CPU core Interrupt Numbers
+ */
+#define MIPS_CPU_IRQ_BASE	0
+#define MIPS_CPU_IRQ(x)		(MIPS_CPU_IRQ_BASE + (x))
+#define MIPS_SOFTINT0_IRQ	MIPS_CPU_IRQ(0)
+#define MIPS_SOFTINT1_IRQ	MIPS_CPU_IRQ(1)
+#define RCP_IRQ			MIPS_CPU_IRQ(2)
+#define CART_IRQ		MIPS_CPU_IRQ(3)
+#define PRENMI_IRQ		MIPS_CPU_IRQ(4)
+#define RDBR_IRQ		MIPS_CPU_IRQ(5)
+#define RDBW_IRQ		MIPS_CPU_IRQ(6)
+#define TIMER_IRQ		MIPS_CPU_IRQ(7)
+
+#endif /* __N64_IRQ_H */
diff --git a/arch/mips/n64/Makefile b/arch/mips/n64/Makefile
new file mode 100644
index 0000000..b64a05a
--- /dev/null
+++ b/arch/mips/n64/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Nintendo 64
+#
+
+obj-y := init.o irq.o
diff --git a/arch/mips/n64/Platform b/arch/mips/n64/Platform
new file mode 100644
index 0000000..bf5edba
--- /dev/null
+++ b/arch/mips/n64/Platform
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Nintendo 64
+#
+
+cflags-$(CONFIG_MIPS_N64)    += -I$(srctree)/arch/mips/include/asm/mach-n64
+load-$(CONFIG_MIPS_N64)      += 0xffffffff80101000
diff --git a/arch/mips/n64/init.c b/arch/mips/n64/init.c
new file mode 100644
index 0000000..6fb622d
--- /dev/null
+++ b/arch/mips/n64/init.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Nintendo 64 init.
+ *
+ *  Copyright (C) 2020	Lauri Kasanen
+ */
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/memblock.h>
+#include <linux/string.h>
+
+#include <asm/bootinfo.h>
+#include <asm/time.h>
+
+#define IO_MEM_RESOURCE_START	0UL
+#define IO_MEM_RESOURCE_END	0x1fffffffUL
+
+static void __init iomem_resource_init(void)
+{
+	iomem_resource.start = IO_MEM_RESOURCE_START;
+	iomem_resource.end = IO_MEM_RESOURCE_END;
+}
+
+const char *get_system_type(void)
+{
+	return "Nintendo 64";
+}
+
+void __init prom_init(void)
+{
+	int argc, i;
+	const char **argv;
+
+	argc = fw_arg0;
+	argv = (const char **)fw_arg1;
+
+	for (i = 1; i < argc; i++) {
+		strlcat(arcs_cmdline, argv[i], COMMAND_LINE_SIZE);
+		if (i < (argc - 1))
+			strlcat(arcs_cmdline, " ", COMMAND_LINE_SIZE);
+	}
+}
+
+void __init prom_free_prom_memory(void)
+{
+}
+
+void __init plat_mem_setup(void)
+{
+	iomem_resource_init();
+	memblock_add(0x0, 8 * 1024 * 1024); // Bootloader blocks the 4mb config
+}
+
+void __init plat_time_init(void)
+{
+	// 93.75 MHz cpu, count register runs at half rate
+	mips_hpt_frequency = 93750000 / 2;
+}
diff --git a/arch/mips/n64/irq.c b/arch/mips/n64/irq.c
new file mode 100644
index 0000000..3eb0079
--- /dev/null
+++ b/arch/mips/n64/irq.c
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  N64 IRQ
+ *
+ *  Copyright (C) 2020 Lauri Kasanen
+ */
+#include <linux/export.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+
+#include <asm/irq_cpu.h>
+
+asmlinkage void plat_irq_dispatch(void)
+{
+	unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
+
+	if (pending & CAUSEF_IP7)
+		do_IRQ(TIMER_IRQ);
+	else if (pending & CAUSEF_IP4)
+		do_IRQ(PRENMI_IRQ);
+	else if (pending & CAUSEF_IP2)
+		do_IRQ(RCP_IRQ);
+	else if (pending & CAUSEF_IP0)
+		do_IRQ(MIPS_SOFTINT0_IRQ);
+	else if (pending & CAUSEF_IP1)
+		do_IRQ(MIPS_SOFTINT1_IRQ);
+	else
+		spurious_interrupt();
+}
+
+void __init arch_init_irq(void)
+{
+	mips_cpu_irq_init();
+}
--
2.6.2