xref: /linux/arch/nios2/kernel/prom.c (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
1 /*
2  * Device tree support
3  *
4  * Copyright (C) 2013, 2015 Altera Corporation
5  * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
6  *
7  * Based on MIPS support for CONFIG_OF device tree support
8  *
9  * Copyright (C) 2010 Cisco Systems Inc. <dediao@cisco.com>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
23  *
24  */
25 
26 #include <linux/init.h>
27 #include <linux/types.h>
28 #include <linux/bootmem.h>
29 #include <linux/of.h>
30 #include <linux/of_fdt.h>
31 #include <linux/io.h>
32 
33 #include <asm/prom.h>
34 #include <asm/sections.h>
35 
36 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
37 {
38 	u64 kernel_start = (u64)virt_to_phys(_text);
39 
40 	if (!memory_size &&
41 	    (kernel_start >= base) && (kernel_start < (base + size)))
42 		memory_size = size;
43 
44 }
45 
46 void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
47 {
48 	return alloc_bootmem_align(size, align);
49 }
50 
51 void __init early_init_devtree(void *params)
52 {
53 	__be32 *dtb = (u32 *)__dtb_start;
54 #if defined(CONFIG_NIOS2_DTB_AT_PHYS_ADDR)
55 	if (be32_to_cpup((__be32 *)CONFIG_NIOS2_DTB_PHYS_ADDR) ==
56 		 OF_DT_HEADER) {
57 		params = (void *)CONFIG_NIOS2_DTB_PHYS_ADDR;
58 		early_init_dt_scan(params);
59 		return;
60 	}
61 #endif
62 	if (be32_to_cpu((__be32) *dtb) == OF_DT_HEADER)
63 		params = (void *)__dtb_start;
64 
65 	early_init_dt_scan(params);
66 }
67 
68 #ifdef CONFIG_EARLY_PRINTK
69 static int __init early_init_dt_scan_serial(unsigned long node,
70 			const char *uname, int depth, void *data)
71 {
72 	u64 *addr64 = (u64 *) data;
73 	const char *p;
74 
75 	/* only consider serial nodes */
76 	if (strncmp(uname, "serial", 6) != 0)
77 		return 0;
78 
79 	p = of_get_flat_dt_prop(node, "compatible", NULL);
80 	if (!p)
81 		return 0;
82 
83 	/*
84 	 * We found an altera_jtaguart but it wasn't configured for console, so
85 	 * skip it.
86 	 */
87 #ifndef CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE
88 	if (strncmp(p, "altr,juart", 10) == 0)
89 		return 0;
90 #endif
91 
92 	/*
93 	 * Same for altera_uart.
94 	 */
95 #ifndef CONFIG_SERIAL_ALTERA_UART_CONSOLE
96 	if (strncmp(p, "altr,uart", 9) == 0)
97 		return 0;
98 #endif
99 
100 	*addr64 = of_flat_dt_translate_address(node);
101 
102 	return *addr64 == OF_BAD_ADDR ? 0 : 1;
103 }
104 
105 unsigned long __init of_early_console(void)
106 {
107 	u64 base = 0;
108 
109 	if (of_scan_flat_dt(early_init_dt_scan_serial, &base))
110 		return (u32)ioremap(base, 32);
111 	else
112 		return 0;
113 }
114 #endif /* CONFIG_EARLY_PRINTK */
115