xref: /openbmc/linux/arch/mips/rb532/prom.c (revision be709d48)
1 /*
2  *  RouterBoard 500 specific prom routines
3  *
4  *  Copyright (C) 2003, Peter Sadik <peter.sadik@idt.com>
5  *  Copyright (C) 2005-2006, P.Christeas <p_christ@hol.gr>
6  *  Copyright (C) 2007, Gabor Juhos <juhosg@openwrt.org>
7  *			Felix Fietkau <nbd@openwrt.org>
8  *			Florian Fainelli <florian@openwrt.org>
9  *
10  *  This program is free software; you can redistribute it and/or
11  *  modify it under the terms of the GNU General Public License
12  *  as published by the Free Software Foundation; either version 2
13  *  of the License, or (at your option) any later version.
14  *
15  *  This program is distributed in the hope that it will be useful,
16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  *  GNU General Public License for more details.
19  *
20  *  You should have received a copy of the GNU General Public License
21  *  along with this program; if not, write to the
22  *  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
23  *  Boston, MA  02110-1301, USA.
24  *
25  */
26 
27 #include <linux/init.h>
28 #include <linux/mm.h>
29 #include <linux/export.h>
30 #include <linux/string.h>
31 #include <linux/console.h>
32 #include <linux/memblock.h>
33 #include <linux/ioport.h>
34 #include <linux/blkdev.h>
35 
36 #include <asm/bootinfo.h>
37 #include <asm/mach-rc32434/ddr.h>
38 #include <asm/mach-rc32434/prom.h>
39 
40 unsigned int idt_cpu_freq = 132000000;
41 EXPORT_SYMBOL(idt_cpu_freq);
42 
43 static struct resource ddr_reg[] = {
44 	{
45 		.name = "ddr-reg",
46 		.start = DDR0_PHYS_ADDR,
47 		.end = DDR0_PHYS_ADDR + sizeof(struct ddr_ram),
48 		.flags = IORESOURCE_MEM,
49 	}
50 };
51 
52 void __init prom_free_prom_memory(void)
53 {
54 	/* No prom memory to free */
55 }
56 
57 static inline int match_tag(char *arg, const char *tag)
58 {
59 	return strncmp(arg, tag, strlen(tag)) == 0;
60 }
61 
62 static inline unsigned long tag2ul(char *arg, const char *tag)
63 {
64 	char *num;
65 
66 	num = arg + strlen(tag);
67 	return simple_strtoul(num, 0, 10);
68 }
69 
70 void __init prom_setup_cmdline(void)
71 {
72 	static char cmd_line[COMMAND_LINE_SIZE] __initdata;
73 	char *cp, *board;
74 	int prom_argc;
75 	char **prom_argv;
76 	int i;
77 
78 	prom_argc = fw_arg0;
79 	prom_argv = (char **) fw_arg1;
80 
81 	cp = cmd_line;
82 		/* Note: it is common that parameters start
83 		 * at argv[1] and not argv[0],
84 		 * however, our elf loader starts at [0] */
85 	for (i = 0; i < prom_argc; i++) {
86 		if (match_tag(prom_argv[i], FREQ_TAG)) {
87 			idt_cpu_freq = tag2ul(prom_argv[i], FREQ_TAG);
88 			continue;
89 		}
90 #ifdef IGNORE_CMDLINE_MEM
91 		/* parses out the "mem=xx" arg */
92 		if (match_tag(prom_argv[i], MEM_TAG))
93 			continue;
94 #endif
95 		if (i > 0)
96 			*(cp++) = ' ';
97 		if (match_tag(prom_argv[i], BOARD_TAG)) {
98 			board = prom_argv[i] + strlen(BOARD_TAG);
99 
100 			if (match_tag(board, BOARD_RB532A))
101 				mips_machtype = MACH_MIKROTIK_RB532A;
102 			else
103 				mips_machtype = MACH_MIKROTIK_RB532;
104 		}
105 
106 		strcpy(cp, prom_argv[i]);
107 		cp += strlen(prom_argv[i]);
108 	}
109 	*(cp++) = ' ';
110 
111 	i = strlen(arcs_cmdline);
112 	if (i > 0) {
113 		*(cp++) = ' ';
114 		strcpy(cp, arcs_cmdline);
115 		cp += strlen(arcs_cmdline);
116 	}
117 	cmd_line[COMMAND_LINE_SIZE - 1] = '\0';
118 
119 	strcpy(arcs_cmdline, cmd_line);
120 }
121 
122 void __init prom_init(void)
123 {
124 	struct ddr_ram __iomem *ddr;
125 	phys_addr_t memsize;
126 	phys_addr_t ddrbase;
127 
128 	ddr = ioremap_nocache(ddr_reg[0].start,
129 			ddr_reg[0].end - ddr_reg[0].start);
130 
131 	if (!ddr) {
132 		printk(KERN_ERR "Unable to remap DDR register\n");
133 		return;
134 	}
135 
136 	ddrbase = (phys_addr_t)&ddr->ddrbase;
137 	memsize = (phys_addr_t)&ddr->ddrmask;
138 	memsize = 0 - memsize;
139 
140 	prom_setup_cmdline();
141 
142 	/* give all RAM to boot allocator,
143 	 * except for the first 0x400 and the last 0x200 bytes */
144 	add_memory_region(ddrbase + 0x400, memsize - 0x600, BOOT_MEM_RAM);
145 }
146