arch/mips/ralink/clk.c

   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 }