1 files changed, 92 insertions, 0 deletions
diff --git a/arch/mips/mti-sead3/sead3-dtshim.c b/arch/mips/mti-sead3/sead3-dtshim.c
new file mode 100644
index 000000000000..3283a7e19a88
--- /dev/null
+++ b/arch/mips/mti-sead3/sead3-dtshim.c
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#define pr_fmt(fmt) "sead3-dtshim: " fmt
+
+#include <linux/errno.h>
+#include <linux/libfdt.h>
+#include <linux/printk.h>
+
+#include <asm/io.h>
+
+#define SEAD_CONFIG			CKSEG1ADDR(0x1b100110)
+#define SEAD_CONFIG_GIC_PRESENT		BIT(1)
+
+static unsigned char fdt_buf[16 << 10] __initdata;
+
+static int remove_gic(void *fdt)
+{
+	int gic_off, cpu_off, err;
+	uint32_t cfg, cpu_phandle;
+
+	/* leave the GIC node intact if a GIC is present */
+	cfg = __raw_readl((uint32_t *)SEAD_CONFIG);
+	if (cfg & SEAD_CONFIG_GIC_PRESENT)
+		return 0;
+
+	gic_off = fdt_node_offset_by_compatible(fdt, -1, "mti,gic");
+	if (gic_off < 0) {
+		pr_err("unable to find DT GIC node: %d\n", gic_off);
+		return gic_off;
+	}
+
+	err = fdt_nop_node(fdt, gic_off);
+	if (err) {
+		pr_err("unable to nop GIC node\n");
+		return err;
+	}
+
+	cpu_off = fdt_node_offset_by_compatible(fdt, -1,
+			"mti,cpu-interrupt-controller");
+	if (cpu_off < 0) {
+		pr_err("unable to find CPU intc node: %d\n", cpu_off);
+		return cpu_off;
+	}
+
+	cpu_phandle = fdt_get_phandle(fdt, cpu_off);
+	if (!cpu_phandle) {
+		pr_err("unable to get CPU intc phandle\n");
+		return -EINVAL;
+	}
+
+	err = fdt_setprop_u32(fdt, 0, "interrupt-parent", cpu_phandle);
+	if (err) {
+		pr_err("unable to set root interrupt-parent: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
+void __init *sead3_dt_shim(void *fdt)
+{
+	int err;
+
+	if (fdt_check_header(fdt))
+		panic("Corrupt DT");
+
+	/* if this isn't SEAD3, leave the DT alone */
+	if (fdt_node_check_compatible(fdt, 0, "mti,sead-3"))
+		return fdt;
+
+	err = fdt_open_into(fdt, fdt_buf, sizeof(fdt_buf));
+	if (err)
+		panic("Unable to open FDT: %d", err);
+
+	err = remove_gic(fdt_buf);
+	if (err)
+		panic("Unable to patch FDT: %d", err);
+
+	err = fdt_pack(fdt_buf);
+	if (err)
+		panic("Unable to pack FDT: %d\n", err);
+
+	return fdt_buf;
+}