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
24unsigned int idt_cpu_freq = 132000000;
25EXPORT_SYMBOL(idt_cpu_freq);
26
27static 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
36static inline int match_tag(char *arg, const char *tag)
37{
38	return strncmp(arg, tag, strlen(tag)) == 0;
39}
40
41static 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
49void __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
101void __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