loongson2ef/common/env.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Based on Ocelot Linux port, which is
0004  * Copyright 2001 MontaVista Software Inc.
0005  * Author: jsun@mvista.com or jsun@junsun.net
0006  *
0007  * Copyright 2003 ICT CAS
0008  * Author: Michael Guo <guoyi@ict.ac.cn>
0009  *
0010  * Copyright (C) 2007 Lemote Inc. & Institute of Computing Technology
0011  * Author: Fuxin Zhang, zhangfx@lemote.com
0012  *
0013  * Copyright (C) 2009 Lemote Inc.
0014  * Author: Wu Zhangjin, wuzhangjin@gmail.com
0015  */
0016 #include <linux/export.h>
0017 #include <asm/bootinfo.h>
0018 #include <asm/fw/fw.h>
0019 #include <loongson.h>
0020
0021 u32 cpu_clock_freq;
0022 EXPORT_SYMBOL(cpu_clock_freq);
0023
0024 void __init prom_init_env(void)
0025 {
0026     /* pmon passes arguments in 32bit pointers */
0027     unsigned int processor_id;
0028
0029     cpu_clock_freq = fw_getenvl("cpuclock");
0030     memsize = fw_getenvl("memsize");
0031     highmemsize = fw_getenvl("highmemsize");
0032
0033     if (memsize == 0)
0034         memsize = 256;
0035
0036     pr_info("memsize=%u, highmemsize=%u\n", memsize, highmemsize);
0037
0038     if (cpu_clock_freq == 0) {
0039         processor_id = (&current_cpu_data)->processor_id;
0040         switch (processor_id & PRID_REV_MASK) {
0041         case PRID_REV_LOONGSON2E:
0042             cpu_clock_freq = 533080000;
0043             break;
0044         case PRID_REV_LOONGSON2F:
0045             cpu_clock_freq = 797000000;
0046             break;
0047         default:
0048             cpu_clock_freq = 100000000;
0049             break;
0050         }
0051     }
0052     pr_info("CpuClock = %u\n", cpu_clock_freq);
0053 }