1/*
2 * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
3 *
4 * Based on reduced version of METAG
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11
12#include <linux/init.h>
13#include <linux/reboot.h>
14#include <linux/memblock.h>
15#include <linux/of.h>
16#include <linux/of_fdt.h>
17#include <asm/clk.h>
18#include <asm/mach_desc.h>
19
20#ifdef CONFIG_SERIAL_EARLYCON
21
22static unsigned int __initdata arc_base_baud;
23
24unsigned int __init arc_early_base_baud(void)
25{
26	return arc_base_baud/16;
27}
28
29static void __init arc_set_early_base_baud(unsigned long dt_root)
30{
31	unsigned int core_clk = arc_get_core_freq();
32
33	if (of_flat_dt_is_compatible(dt_root, "abilis,arc-tb10x"))
34		arc_base_baud = core_clk/3;
35	else if (of_flat_dt_is_compatible(dt_root, "snps,arc-sdp"))
36		arc_base_baud = 33333333;	/* Fixed 33MHz clk (AXS10x) */
37	else
38		arc_base_baud = core_clk;
39}
40#else
41#define arc_set_early_base_baud(dt_root)
42#endif
43
44static const void * __init arch_get_next_mach(const char *const **match)
45{
46	static const struct machine_desc *mdesc = __arch_info_begin;
47	const struct machine_desc *m = mdesc;
48
49	if (m >= __arch_info_end)
50		return NULL;
51
52	mdesc++;
53	*match = m->dt_compat;
54	return m;
55}
56
57/**
58 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
59 * @dt:		virtual address pointer to dt blob
60 *
61 * If a dtb was passed to the kernel, then use it to choose the correct
62 * machine_desc and to setup the system.
63 */
64const struct machine_desc * __init setup_machine_fdt(void *dt)
65{
66	const struct machine_desc *mdesc;
67	unsigned long dt_root;
68	const void *clk;
69	int len;
70
71	if (!early_init_dt_scan(dt))
72		return NULL;
73
74	mdesc = of_flat_dt_match_machine(NULL, arch_get_next_mach);
75	if (!mdesc)
76		machine_halt();
77
78	dt_root = of_get_flat_dt_root();
79	clk = of_get_flat_dt_prop(dt_root, "clock-frequency", &len);
80	if (clk)
81		arc_set_core_freq(of_read_ulong(clk, len/4));
82
83	arc_set_early_base_baud(dt_root);
84
85	return mdesc;
86}
87