arch/mips/loongson2ef/common/env.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Based on Ocelot Linux port, which is
   4  * Copyright 2001 MontaVista Software Inc.
   5  * Author: jsun@mvista.com or jsun@junsun.net
   6  *
   7  * Copyright 2003 ICT CAS
   8  * Author: Michael Guo <guoyi@ict.ac.cn>
   9  *
  10  * Copyright (C) 2007 Lemote Inc. & Institute of Computing Technology
  11  * Author: Fuxin Zhang, zhangfx@lemote.com
  12  *
  13  * Copyright (C) 2009 Lemote Inc.
  14  * Author: Wu Zhangjin, wuzhangjin@gmail.com
  15  */
  16 #include <linux/export.h>
  17 #include <asm/bootinfo.h>
  18 #include <asm/fw/fw.h>
  19 #include <loongson.h>
  20
  21 u32 cpu_clock_freq;
  22 EXPORT_SYMBOL(cpu_clock_freq);
  23
  24 void __init prom_init_env(void)
  25 {
  26         /* pmon passes arguments in 32bit pointers */
  27         unsigned int processor_id;
  28
  29         cpu_clock_freq = fw_getenvl("cpuclock");
  30         memsize = fw_getenvl("memsize");
  31         highmemsize = fw_getenvl("highmemsize");
  32
  33         if (memsize == 0)
  34                 memsize = 256;
  35
  36         pr_info("memsize=%u, highmemsize=%u\n", memsize, highmemsize);
  37
  38         if (cpu_clock_freq == 0) {
  39                 processor_id = (&current_cpu_data)->processor_id;
  40                 switch (processor_id & PRID_REV_MASK) {
  41                 case PRID_REV_LOONGSON2E:
  42                         cpu_clock_freq = 533080000;
  43                         break;
  44                 case PRID_REV_LOONGSON2F:
  45                         cpu_clock_freq = 797000000;
  46                         break;
  47                 default:
  48                         cpu_clock_freq = 100000000;
  49                         break;
  50                 }
  51         }
  52         pr_info("CpuClock = %u\n", cpu_clock_freq);
  53 }