LXR linux/arch/mips/loongson/common/env.c

   1/*
   2 * Based on Ocelot Linux port, which is
   3 * Copyright 2001 MontaVista Software Inc.
   4 * Author: jsun@mvista.com or jsun@junsun.net
   5 *
   6 * Copyright 2003 ICT CAS
   7 * Author: Michael Guo <guoyi@ict.ac.cn>
   8 *
   9 * Copyright (C) 2007 Lemote Inc. & Insititute of Computing Technology
  10 * Author: Fuxin Zhang, zhangfx@lemote.com
  11 *
  12 * Copyright (C) 2009 Lemote Inc.
  13 * Author: Wu Zhangjin, wuzhangjin@gmail.com
  14 *
  15 * This program is free software; you can redistribute  it and/or modify it
  16 * under  the terms of  the GNU General  Public License as published by the
  17 * Free Software Foundation;  either version 2 of the  License, or (at your
  18 * option) any later version.
  19 */
  20#include <linux/module.h>
  21
  22#include <asm/bootinfo.h>
  23
  24#include <loongson.h>
  25
  26unsigned long cpu_clock_freq;
  27EXPORT_SYMBOL(cpu_clock_freq);
  28unsigned long memsize, highmemsize;
  29
  30#define parse_even_earlier(res, option, p)                              \
  31do {                                                                    \
  32        unsigned int tmp __maybe_unused;                                \
  33                                                                        \
  34        if (strncmp(option, (char *)p, strlen(option)) == 0)            \
  35                tmp = strict_strtol((char *)p + strlen(option"="), 10, &res); \
  36} while (0)
  37
  38void __init prom_init_env(void)
  39{
  40        /* pmon passes arguments in 32bit pointers */
  41        int *_prom_envp;
  42        unsigned long bus_clock;
  43        unsigned int processor_id;
  44        long l;
  45
  46        /* firmware arguments are initialized in head.S */
  47        _prom_envp = (int *)fw_arg2;
  48
  49        l = (long)*_prom_envp;
  50        while (l != 0) {
  51                parse_even_earlier(bus_clock, "busclock", l);
  52                parse_even_earlier(cpu_clock_freq, "cpuclock", l);
  53                parse_even_earlier(memsize, "memsize", l);
  54                parse_even_earlier(highmemsize, "highmemsize", l);
  55                _prom_envp++;
  56                l = (long)*_prom_envp;
  57        }
  58        if (memsize == 0)
  59                memsize = 256;
  60        if (bus_clock == 0)
  61                bus_clock = 66000000;
  62        if (cpu_clock_freq == 0) {
  63                processor_id = (&current_cpu_data)->processor_id;
  64                switch (processor_id & PRID_REV_MASK) {
  65                case PRID_REV_LOONGSON2E:
  66                        cpu_clock_freq = 533080000;
  67                        break;
  68                case PRID_REV_LOONGSON2F:
  69                        cpu_clock_freq = 797000000;
  70                        break;
  71                default:
  72                        cpu_clock_freq = 100000000;
  73                        break;
  74                }
  75        }
  76
  77        pr_info("busclock=%ld, cpuclock=%ld, memsize=%ld, highmemsize=%ld\n",
  78                bus_clock, cpu_clock_freq, memsize, highmemsize);
  79}
  80