MIPS: Add support for PIC32MZDA platform

This adds support for the Microchip PIC32 MIPS microcontroller with the
specific variant PIC32MZDA. PIC32MZDA is based on the MIPS m14KEc core
and boots using device tree.

This includes an early pin setup and early clock setup needed prior to
device tree being initialized. In additon, an interface is provided to
synchronize access to registers shared across several peripherals.

Signed-off-by: Joshua Henderson <joshua.henderson@microchip.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12097/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 88 insertions, 0 deletions

diff --git a/arch/mips/pic32/common/Makefile b/arch/mips/pic32/common/Makefile
new file mode 100644
index 000000000000..be1909cc0467
--- /dev/null
+++ b/arch/mips/pic32/common/Makefile
@@ -0,0 +1,5 @@
+#
+# Joshua Henderson, <joshua.henderson@microchip.com>
+# Copyright (C) 2015 Microchip Technology, Inc.  All rights reserved.
+#
+obj-y = reset.o irq.o
diff --git a/arch/mips/pic32/common/irq.c b/arch/mips/pic32/common/irq.c
new file mode 100644
index 000000000000..6df347e36036
--- /dev/null
+++ b/arch/mips/pic32/common/irq.c
@@ -0,0 +1,21 @@
+/*
+ * Joshua Henderson <joshua.henderson@microchip.com>
+ * Copyright (C) 2015 Microchip Technology Inc.  All rights reserved.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ */
+#include <linux/init.h>
+#include <linux/irqchip.h>
+#include <asm/irq.h>
+
+void __init arch_init_irq(void)
+{
+	irqchip_init();
+}
diff --git a/arch/mips/pic32/common/reset.c b/arch/mips/pic32/common/reset.c
new file mode 100644
index 000000000000..83345757be5f
--- /dev/null
+++ b/arch/mips/pic32/common/reset.c
@@ -0,0 +1,62 @@
+/*
+ * Joshua Henderson <joshua.henderson@microchip.com>
+ * Copyright (C) 2015 Microchip Technology Inc.  All rights reserved.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ */
+#include <linux/init.h>
+#include <linux/pm.h>
+#include <asm/reboot.h>
+#include <asm/mach-pic32/pic32.h>
+
+#define PIC32_RSWRST		0x10
+
+static void pic32_halt(void)
+{
+	while (1) {
+		__asm__(".set push;\n"
+			".set arch=r4000;\n"
+			"wait;\n"
+			".set pop;\n"
+		);
+	}
+}
+
+static void pic32_machine_restart(char *command)
+{
+	void __iomem *reg =
+		ioremap(PIC32_BASE_RESET + PIC32_RSWRST, sizeof(u32));
+
+	pic32_syskey_unlock();
+
+	/* magic write/read */
+	__raw_writel(1, reg);
+	(void)__raw_readl(reg);
+
+	pic32_halt();
+}
+
+static void pic32_machine_halt(void)
+{
+	local_irq_disable();
+
+	pic32_halt();
+}
+
+static int __init mips_reboot_setup(void)
+{
+	_machine_restart = pic32_machine_restart;
+	_machine_halt = pic32_machine_halt;
+	pm_power_off = pic32_machine_halt;
+
+	return 0;
+}
+
+arch_initcall(mips_reboot_setup);