1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  RouterBoard 500 specific prom routines
4  *
5  *  Copyright (C) 2003, Peter Sadik <peter.sadik@idt.com>
6  *  Copyright (C) 2005-2006, P.Christeas <p_christ@hol.gr>
7  *  Copyright (C) 2007, Gabor Juhos <juhosg@openwrt.org>
8  *			Felix Fietkau <nbd@openwrt.org>
9  *			Florian Fainelli <florian@openwrt.org>
10  */
11 
12 #include <linux/init.h>
13 #include <linux/mm.h>
14 #include <linux/export.h>
15 #include <linux/string.h>
16 #include <linux/console.h>
17 #include <linux/memblock.h>
18 #include <linux/ioport.h>
19 
20 #include <asm/bootinfo.h>
21 #include <asm/mach-rc32434/ddr.h>
22 #include <asm/mach-rc32434/prom.h>
23 
24 unsigned int idt_cpu_freq = 132000000;
25 EXPORT_SYMBOL(idt_cpu_freq);
26 
27 static struct resource ddr_reg[] = {
28 	{
29 		.name = "ddr-reg",
30 		.start = DDR0_PHYS_ADDR,
31 		.end = DDR0_PHYS_ADDR + sizeof(struct ddr_ram),
32 		.flags = IORESOURCE_MEM,
33 	}
34 };
35 
match_tag(char * arg,const char * tag)36 static inline int match_tag(char *arg, const char *tag)
37 {
38 	return strncmp(arg, tag, strlen(tag)) == 0;
39 }
40 
tag2ul(char * arg,const char * tag)41 static inline unsigned long tag2ul(char *arg, const char *tag)
42 {
43 	char *num;
44 
45 	num = arg + strlen(tag);
46 	return simple_strtoul(num, 0, 10);
47 }
48 
prom_setup_cmdline(void)49 void __init prom_setup_cmdline(void)
50 {
51 	static char cmd_line[COMMAND_LINE_SIZE] __initdata;
52 	char *cp, *board;
53 	int prom_argc;
54 	char **prom_argv;
55 	int i;
56 
57 	prom_argc = fw_arg0;
58 	prom_argv = (char **) fw_arg1;
59 
60 	cp = cmd_line;
61 		/* Note: it is common that parameters start
62 		 * at argv[1] and not argv[0],
63 		 * however, our elf loader starts at [0] */
64 	for (i = 0; i < prom_argc; i++) {
65 		if (match_tag(prom_argv[i], FREQ_TAG)) {
66 			idt_cpu_freq = tag2ul(prom_argv[i], FREQ_TAG);
67 			continue;
68 		}
69 #ifdef IGNORE_CMDLINE_MEM
70 		/* parses out the "mem=xx" arg */
71 		if (match_tag(prom_argv[i], MEM_TAG))
72 			continue;
73 #endif
74 		if (i > 0)
75 			*(cp++) = ' ';
76 		if (match_tag(prom_argv[i], BOARD_TAG)) {
77 			board = prom_argv[i] + strlen(BOARD_TAG);
78 
79 			if (match_tag(board, BOARD_RB532A))
80 				mips_machtype = MACH_MIKROTIK_RB532A;
81 			else
82 				mips_machtype = MACH_MIKROTIK_RB532;
83 		}
84 
85 		strcpy(cp, prom_argv[i]);
86 		cp += strlen(prom_argv[i]);
87 	}
88 	*(cp++) = ' ';
89 
90 	i = strlen(arcs_cmdline);
91 	if (i > 0) {
92 		*(cp++) = ' ';
93 		strcpy(cp, arcs_cmdline);
94 		cp += strlen(arcs_cmdline);
95 	}
96 	cmd_line[COMMAND_LINE_SIZE - 1] = '\0';
97 
98 	strcpy(arcs_cmdline, cmd_line);
99 }
100 
prom_init(void)101 void __init prom_init(void)
102 {
103 	struct ddr_ram __iomem *ddr;
104 	phys_addr_t memsize;
105 	phys_addr_t ddrbase;
106 
107 	ddr = ioremap(ddr_reg[0].start,
108 			ddr_reg[0].end - ddr_reg[0].start);
109 
110 	if (!ddr) {
111 		printk(KERN_ERR "Unable to remap DDR register\n");
112 		return;
113 	}
114 
115 	ddrbase = (phys_addr_t)&ddr->ddrbase;
116 	memsize = (phys_addr_t)&ddr->ddrmask;
117 	memsize = 0 - memsize;
118 
119 	prom_setup_cmdline();
120 
121 	/* give all RAM to boot allocator,
122 	 * except for the first 0x400 and the last 0x200 bytes */
123 	memblock_add(ddrbase + 0x400, memsize - 0x600);
124 }
125