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
36 static inline int match_tag(char *arg, const char *tag)
37 {
38 return strncmp(arg, tag, strlen(tag)) == 0;
39 }
40
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
49 static 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
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
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