arch/mips/ralink/clk.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *
   4  *  Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
   5  *  Copyright (C) 2013 John Crispin <john@phrozen.org>
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/init.h>
  10 #include <linux/export.h>
  11 #include <linux/clkdev.h>
  12 #include <linux/clk.h>
  13
  14 #include <asm/time.h>
  15
  16 #include "common.h"
  17
  18 struct clk {
  19         struct clk_lookup cl;
  20         unsigned long rate;
  21 };
  22
  23 void ralink_clk_add(const char *dev, unsigned long rate)
  24 {
  25         struct clk *clk = kzalloc(sizeof(struct clk), GFP_KERNEL);
  26
  27         if (!clk)
  28                 panic("failed to add clock");
  29
  30         clk->cl.dev_id = dev;
  31         clk->cl.clk = clk;
  32
  33         clk->rate = rate;
  34
  35         clkdev_add(&clk->cl);
  36 }
  37
  38 /*
  39  * Linux clock API
  40  */
  41 int clk_enable(struct clk *clk)
  42 {
  43         return 0;
  44 }
  45 EXPORT_SYMBOL_GPL(clk_enable);
  46
  47 void clk_disable(struct clk *clk)
  48 {
  49 }
  50 EXPORT_SYMBOL_GPL(clk_disable);
  51
  52 unsigned long clk_get_rate(struct clk *clk)
  53 {
  54         if (!clk)
  55                 return 0;
  56
  57         return clk->rate;
  58 }
  59 EXPORT_SYMBOL_GPL(clk_get_rate);
  60
  61 int clk_set_rate(struct clk *clk, unsigned long rate)
  62 {
  63         return -1;
  64 }
  65 EXPORT_SYMBOL_GPL(clk_set_rate);
  66
  67 long clk_round_rate(struct clk *clk, unsigned long rate)
  68 {
  69         return -1;
  70 }
  71 EXPORT_SYMBOL_GPL(clk_round_rate);
  72
  73 void __init plat_time_init(void)
  74 {
  75         struct clk *clk;
  76
  77         ralink_of_remap();
  78
  79         ralink_clk_init();
  80         clk = clk_get_sys("cpu", NULL);
  81         if (IS_ERR(clk))
  82                 panic("unable to get CPU clock, err=%ld", PTR_ERR(clk));
  83         pr_info("CPU Clock: %ldMHz\n", clk_get_rate(clk) / 1000000);
  84         mips_hpt_frequency = clk_get_rate(clk) / 2;
  85         clk_put(clk);
  86         timer_probe();
  87 }