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 #include <linux/blkdev.h> 20 21 #include <asm/bootinfo.h> 22 #include <asm/mach-rc32434/ddr.h> 23 #include <asm/mach-rc32434/prom.h> 24 25 unsigned int idt_cpu_freq = 132000000; 26 EXPORT_SYMBOL(idt_cpu_freq); 27 28 static struct resource ddr_reg[] = { 29 { 30 .name = "ddr-reg", 31 .start = DDR0_PHYS_ADDR, 32 .end = DDR0_PHYS_ADDR + sizeof(struct ddr_ram), 33 .flags = IORESOURCE_MEM, 34 } 35 }; 36 37 void __init prom_free_prom_memory(void) 38 { 39 /* No prom memory to free */ 40 } 41 42 static inline int match_tag(char *arg, const char *tag) 43 { 44 return strncmp(arg, tag, strlen(tag)) == 0; 45 } 46 47 static inline unsigned long tag2ul(char *arg, const char *tag) 48 { 49 char *num; 50 51 num = arg + strlen(tag); 52 return simple_strtoul(num, 0, 10); 53 } 54 55 void __init prom_setup_cmdline(void) 56 { 57 static char cmd_line[COMMAND_LINE_SIZE] __initdata; 58 char *cp, *board; 59 int prom_argc; 60 char **prom_argv; 61 int i; 62 63 prom_argc = fw_arg0; 64 prom_argv = (char **) fw_arg1; 65 66 cp = cmd_line; 67 /* Note: it is common that parameters start 68 * at argv[1] and not argv[0], 69 * however, our elf loader starts at [0] */ 70 for (i = 0; i < prom_argc; i++) { 71 if (match_tag(prom_argv[i], FREQ_TAG)) { 72 idt_cpu_freq = tag2ul(prom_argv[i], FREQ_TAG); 73 continue; 74 } 75 #ifdef IGNORE_CMDLINE_MEM 76 /* parses out the "mem=xx" arg */ 77 if (match_tag(prom_argv[i], MEM_TAG)) 78 continue; 79 #endif 80 if (i > 0) 81 *(cp++) = ' '; 82 if (match_tag(prom_argv[i], BOARD_TAG)) { 83 board = prom_argv[i] + strlen(BOARD_TAG); 84 85 if (match_tag(board, BOARD_RB532A)) 86 mips_machtype = MACH_MIKROTIK_RB532A; 87 else 88 mips_machtype = MACH_MIKROTIK_RB532; 89 } 90 91 strcpy(cp, prom_argv[i]); 92 cp += strlen(prom_argv[i]); 93 } 94 *(cp++) = ' '; 95 96 i = strlen(arcs_cmdline); 97 if (i > 0) { 98 *(cp++) = ' '; 99 strcpy(cp, arcs_cmdline); 100 cp += strlen(arcs_cmdline); 101 } 102 cmd_line[COMMAND_LINE_SIZE - 1] = '\0'; 103 104 strcpy(arcs_cmdline, cmd_line); 105 } 106 107 void __init prom_init(void) 108 { 109 struct ddr_ram __iomem *ddr; 110 phys_addr_t memsize; 111 phys_addr_t ddrbase; 112 113 ddr = ioremap(ddr_reg[0].start, 114 ddr_reg[0].end - ddr_reg[0].start); 115 116 if (!ddr) { 117 printk(KERN_ERR "Unable to remap DDR register\n"); 118 return; 119 } 120 121 ddrbase = (phys_addr_t)&ddr->ddrbase; 122 memsize = (phys_addr_t)&ddr->ddrmask; 123 memsize = 0 - memsize; 124 125 prom_setup_cmdline(); 126 127 /* give all RAM to boot allocator, 128 * except for the first 0x400 and the last 0x200 bytes */ 129 memblock_add(ddrbase + 0x400, memsize - 0x600); 130 } 131