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
22 static unsigned int __initdata arc_base_baud;
23
arc_early_base_baud(void)24 unsigned int __init arc_early_base_baud(void)
25 {
26 return arc_base_baud/16;
27 }
28
arc_set_early_base_baud(unsigned long dt_root)29 static 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
arch_get_next_mach(const char * const ** match)44 static 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 */
setup_machine_fdt(void * dt)64 const 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