xref: /openbmc/linux/arch/mips/ralink/clk.c (revision 9b93eb47)
1 /*
2  *  This program is free software; you can redistribute it and/or modify it
3  *  under the terms of the GNU General Public License version 2 as published
4  *  by the Free Software Foundation.
5  *
6  *  Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
7  *  Copyright (C) 2013 John Crispin <john@phrozen.org>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/export.h>
13 #include <linux/clkdev.h>
14 #include <linux/clk.h>
15 
16 #include <asm/time.h>
17 
18 #include "common.h"
19 
20 struct clk {
21 	struct clk_lookup cl;
22 	unsigned long rate;
23 };
24 
25 void ralink_clk_add(const char *dev, unsigned long rate)
26 {
27 	struct clk *clk = kzalloc(sizeof(struct clk), GFP_KERNEL);
28 
29 	if (!clk)
30 		panic("failed to add clock");
31 
32 	clk->cl.dev_id = dev;
33 	clk->cl.clk = clk;
34 
35 	clk->rate = rate;
36 
37 	clkdev_add(&clk->cl);
38 }
39 
40 /*
41  * Linux clock API
42  */
43 int clk_enable(struct clk *clk)
44 {
45 	return 0;
46 }
47 EXPORT_SYMBOL_GPL(clk_enable);
48 
49 void clk_disable(struct clk *clk)
50 {
51 }
52 EXPORT_SYMBOL_GPL(clk_disable);
53 
54 unsigned long clk_get_rate(struct clk *clk)
55 {
56 	if (!clk)
57 		return 0;
58 
59 	return clk->rate;
60 }
61 EXPORT_SYMBOL_GPL(clk_get_rate);
62 
63 int clk_set_rate(struct clk *clk, unsigned long rate)
64 {
65 	return -1;
66 }
67 EXPORT_SYMBOL_GPL(clk_set_rate);
68 
69 long clk_round_rate(struct clk *clk, unsigned long rate)
70 {
71 	return -1;
72 }
73 EXPORT_SYMBOL_GPL(clk_round_rate);
74 
75 void __init plat_time_init(void)
76 {
77 	struct clk *clk;
78 
79 	ralink_of_remap();
80 
81 	ralink_clk_init();
82 	clk = clk_get_sys("cpu", NULL);
83 	if (IS_ERR(clk))
84 		panic("unable to get CPU clock, err=%ld", PTR_ERR(clk));
85 	pr_info("CPU Clock: %ldMHz\n", clk_get_rate(clk) / 1000000);
86 	mips_hpt_frequency = clk_get_rate(clk) / 2;
87 	clk_put(clk);
88 	timer_probe();
89 }
90