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 
prom_init_env(void)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 }
54