1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
 4 *
 5 * Based on reduced version of METAG
 6 */
 7
 8
 9#include <linux/init.h>
10#include <linux/reboot.h>
11#include <linux/memblock.h>
12#include <linux/of.h>
13#include <linux/of_fdt.h>
14#include <asm/mach_desc.h>
15
16#ifdef CONFIG_SERIAL_EARLYCON
17
18static unsigned int __initdata arc_base_baud;
19
20unsigned int __init arc_early_base_baud(void)
21{
22	return arc_base_baud/16;
23}
24
25static void __init arc_set_early_base_baud(unsigned long dt_root)
26{
27	if (of_flat_dt_is_compatible(dt_root, "abilis,arc-tb10x"))
28		arc_base_baud = 166666666;	/* Fixed 166.6MHz clk (TB10x) */
29	else if (of_flat_dt_is_compatible(dt_root, "snps,arc-sdp") ||
30		 of_flat_dt_is_compatible(dt_root, "snps,hsdk"))
31		arc_base_baud = 33333333;	/* Fixed 33MHz clk (AXS10x & HSDK) */
32	else if (of_flat_dt_is_compatible(dt_root, "ezchip,arc-nps"))
33		arc_base_baud = 800000000;      /* Fixed 800MHz clk (NPS) */
34	else
35		arc_base_baud = 50000000;	/* Fixed default 50MHz */
36}
37#else
38#define arc_set_early_base_baud(dt_root)
39#endif
40
41static const void * __init arch_get_next_mach(const char *const **match)
42{
43	static const struct machine_desc *mdesc = __arch_info_begin;
44	const struct machine_desc *m = mdesc;
45
46	if (m >= __arch_info_end)
47		return NULL;
48
49	mdesc++;
50	*match = m->dt_compat;
51	return m;
52}
53
54/**
55 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
56 * @dt:		virtual address pointer to dt blob
57 *
58 * If a dtb was passed to the kernel, then use it to choose the correct
59 * machine_desc and to setup the system.
60 */
61const struct machine_desc * __init setup_machine_fdt(void *dt)
62{
63	const struct machine_desc *mdesc;
64	unsigned long dt_root;
65
66	if (!early_init_dt_scan(dt))
67		return NULL;
68
69	mdesc = of_flat_dt_match_machine(NULL, arch_get_next_mach);
70	if (!mdesc)
71		machine_halt();
72
73	dt_root = of_get_flat_dt_root();
74	arc_set_early_base_baud(dt_root);
75
76	return mdesc;
77}