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
  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 }