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