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 
18 static unsigned int __initdata arc_base_baud;
19 
arc_early_base_baud(void)20 unsigned int __init arc_early_base_baud(void)
21 {
22 	return arc_base_baud/16;
23 }
24 
arc_set_early_base_baud(unsigned long dt_root)25 static 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
33 		arc_base_baud = 50000000;	/* Fixed default 50MHz */
34 }
35 #else
36 #define arc_set_early_base_baud(dt_root)
37 #endif
38 
arch_get_next_mach(const char * const ** match)39 static const void * __init arch_get_next_mach(const char *const **match)
40 {
41 	static const struct machine_desc *mdesc = __arch_info_begin;
42 	const struct machine_desc *m = mdesc;
43 
44 	if (m >= __arch_info_end)
45 		return NULL;
46 
47 	mdesc++;
48 	*match = m->dt_compat;
49 	return m;
50 }
51 
52 /**
53  * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
54  * @dt:		virtual address pointer to dt blob
55  *
56  * If a dtb was passed to the kernel, then use it to choose the correct
57  * machine_desc and to setup the system.
58  */
setup_machine_fdt(void * dt)59 const struct machine_desc * __init setup_machine_fdt(void *dt)
60 {
61 	const struct machine_desc *mdesc;
62 	unsigned long dt_root;
63 
64 	if (!early_init_dt_scan(dt))
65 		return NULL;
66 
67 	mdesc = of_flat_dt_match_machine(NULL, arch_get_next_mach);
68 	if (!mdesc)
69 		machine_halt();
70 
71 	dt_root = of_get_flat_dt_root();
72 	arc_set_early_base_baud(dt_root);
73 
74 	return mdesc;
75 }
76