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
  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 }