1 files changed, 76 insertions, 0 deletions
diff --git a/arch/arc/kernel/devtree.c b/arch/arc/kernel/devtree.c
new file mode 100644
index 0000000000..4c9e61457b
--- /dev/null
+++ b/arch/arc/kernel/devtree.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * Based on reduced version of METAG
+ */
+
+
+#include <linux/init.h>
+#include <linux/reboot.h>
+#include <linux/memblock.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <asm/mach_desc.h>
+#include <asm/serial.h>
+
+#ifdef CONFIG_SERIAL_EARLYCON
+
+static unsigned int __initdata arc_base_baud;
+
+unsigned int __init arc_early_base_baud(void)
+{
+	return arc_base_baud/16;
+}
+
+static void __init arc_set_early_base_baud(unsigned long dt_root)
+{
+	if (of_flat_dt_is_compatible(dt_root, "abilis,arc-tb10x"))
+		arc_base_baud = 166666666;	/* Fixed 166.6MHz clk (TB10x) */
+	else if (of_flat_dt_is_compatible(dt_root, "snps,arc-sdp") ||
+		 of_flat_dt_is_compatible(dt_root, "snps,hsdk"))
+		arc_base_baud = 33333333;	/* Fixed 33MHz clk (AXS10x & HSDK) */
+	else
+		arc_base_baud = 50000000;	/* Fixed default 50MHz */
+}
+#else
+#define arc_set_early_base_baud(dt_root)
+#endif
+
+static const void * __init arch_get_next_mach(const char *const **match)
+{
+	static const struct machine_desc *mdesc = __arch_info_begin;
+	const struct machine_desc *m = mdesc;
+
+	if (m >= __arch_info_end)
+		return NULL;
+
+	mdesc++;
+	*match = m->dt_compat;
+	return m;
+}
+
+/**
+ * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
+ * @dt:		virtual address pointer to dt blob
+ *
+ * If a dtb was passed to the kernel, then use it to choose the correct
+ * machine_desc and to setup the system.
+ */
+const struct machine_desc * __init setup_machine_fdt(void *dt)
+{
+	const struct machine_desc *mdesc;
+	unsigned long dt_root;
+
+	if (!early_init_dt_scan(dt))
+		return NULL;
+
+	mdesc = of_flat_dt_match_machine(NULL, arch_get_next_mach);
+	if (!mdesc)
+		machine_halt();
+
+	dt_root = of_get_flat_dt_root();
+	arc_set_early_base_baud(dt_root);
+
+	return mdesc;
+}