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 size_t len; 57 58 prom_argc = fw_arg0; 59 prom_argv = (char **) fw_arg1; 60 61 cp = cmd_line; 62 /* Note: it is common that parameters start 63 * at argv[1] and not argv[0], 64 * however, our elf loader starts at [0] */ 65 for (i = 0; i < prom_argc; i++) { 66 if (match_tag(prom_argv[i], FREQ_TAG)) { 67 idt_cpu_freq = tag2ul(prom_argv[i], FREQ_TAG); 68 continue; 69 } 70 #ifdef IGNORE_CMDLINE_MEM 71 /* parses out the "mem=xx" arg */ 72 if (match_tag(prom_argv[i], MEM_TAG)) 73 continue; 74 #endif 75 if (i > 0) 76 *(cp++) = ' '; 77 if (match_tag(prom_argv[i], BOARD_TAG)) { 78 board = prom_argv[i] + strlen(BOARD_TAG); 79 80 if (match_tag(board, BOARD_RB532A)) 81 mips_machtype = MACH_MIKROTIK_RB532A; 82 else 83 mips_machtype = MACH_MIKROTIK_RB532; 84 } 85 86 len = strlen(prom_argv[i]); 87 memcpy(cp, prom_argv[i], len + 1); 88 cp += len; 89 } 90 *(cp++) = ' '; 91 92 len = strlen(arcs_cmdline); 93 if (len > 0) { 94 *(cp++) = ' '; 95 memcpy(cp, arcs_cmdline, len + 1); 96 cp += len; 97 } 98 cmd_line[COMMAND_LINE_SIZE - 1] = '\0'; 99 strscpy(arcs_cmdline, cmd_line); 100 } 101 102 void __init prom_init(void) 103 { 104 struct ddr_ram __iomem *ddr; 105 phys_addr_t memsize; 106 phys_addr_t ddrbase; 107 108 ddr = ioremap(ddr_reg[0].start, 109 ddr_reg[0].end - ddr_reg[0].start); 110 111 if (!ddr) { 112 printk(KERN_ERR "Unable to remap DDR register\n"); 113 return; 114 } 115 116 ddrbase = (phys_addr_t)&ddr->ddrbase; 117 memsize = (phys_addr_t)&ddr->ddrmask; 118 memsize = 0 - memsize; 119 120 prom_setup_cmdline(); 121 122 /* give all RAM to boot allocator, 123 * except for the first 0x400 and the last 0x200 bytes */ 124 memblock_add(ddrbase + 0x400, memsize - 0x600); 125 } 126