LXR linux/arch/mips/rb532/prom.c

   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
  25unsigned int idt_cpu_freq = 132000000;
  26EXPORT_SYMBOL(idt_cpu_freq);
  27
  28static 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
  37static inline int match_tag(char *arg, const char *tag)
  38{
  39        return strncmp(arg, tag, strlen(tag)) == 0;
  40}
  41
  42static inline unsigned long tag2ul(char *arg, const char *tag)
  43{
  44        char *num;
  45
  46        num = arg + strlen(tag);
  47        return simple_strtoul(num, 0, 10);
  48}
  49
  50void __init prom_setup_cmdline(void)
  51{
  52        static char cmd_line[COMMAND_LINE_SIZE] __initdata;
  53        char *cp, *board;
  54        int prom_argc;
  55        char **prom_argv;
  56        int i;
  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                strcpy(cp, prom_argv[i]);
  87                cp += strlen(prom_argv[i]);
  88        }
  89        *(cp++) = ' ';
  90
  91        i = strlen(arcs_cmdline);
  92        if (i > 0) {
  93                *(cp++) = ' ';
  94                strcpy(cp, arcs_cmdline);
  95                cp += strlen(arcs_cmdline);
  96        }
  97        cmd_line[COMMAND_LINE_SIZE - 1] = '\0';
  98
  99        strcpy(arcs_cmdline, cmd_line);
 100}
 101
 102void __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