xref: /openbmc/linux/arch/mips/ralink/clk.c (revision 78700c0a)
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/module.h>
12 #include <linux/clkdev.h>
13 #include <linux/clk.h>
14 
15 #include <asm/time.h>
16 
17 #include "common.h"
18 
19 struct clk {
20 	struct clk_lookup cl;
21 	unsigned long rate;
22 };
23 
24 void ralink_clk_add(const char *dev, unsigned long rate)
25 {
26 	struct clk *clk = kzalloc(sizeof(struct clk), GFP_KERNEL);
27 
28 	if (!clk)
29 		panic("failed to add clock");
30 
31 	clk->cl.dev_id = dev;
32 	clk->cl.clk = clk;
33 
34 	clk->rate = rate;
35 
36 	clkdev_add(&clk->cl);
37 }
38 
39 /*
40  * Linux clock API
41  */
42 int clk_enable(struct clk *clk)
43 {
44 	return 0;
45 }
46 EXPORT_SYMBOL_GPL(clk_enable);
47 
48 void clk_disable(struct clk *clk)
49 {
50 }
51 EXPORT_SYMBOL_GPL(clk_disable);
52 
53 unsigned long clk_get_rate(struct clk *clk)
54 {
55 	return clk->rate;
56 }
57 EXPORT_SYMBOL_GPL(clk_get_rate);
58 
59 int clk_set_rate(struct clk *clk, unsigned long rate)
60 {
61 	return -1;
62 }
63 EXPORT_SYMBOL_GPL(clk_set_rate);
64 
65 void __init plat_time_init(void)
66 {
67 	struct clk *clk;
68 
69 	ralink_of_remap();
70 
71 	ralink_clk_init();
72 	clk = clk_get_sys("cpu", NULL);
73 	if (IS_ERR(clk))
74 		panic("unable to get CPU clock, err=%ld", PTR_ERR(clk));
75 	pr_info("CPU Clock: %ldMHz\n", clk_get_rate(clk) / 1000000);
76 	mips_hpt_frequency = clk_get_rate(clk) / 2;
77 	clk_put(clk);
78 	clocksource_probe();
79 }
80