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/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 }