arch/arm/mach-integrator/clock.c

   1 /*
   2  *  linux/arch/arm/mach-integrator/clock.c
   3  *
   4  *  Copyright (C) 2004 ARM Limited.
   5  *  Written by Deep Blue Solutions Limited.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/module.h>
  12 #include <linux/kernel.h>
  13 #include <linux/list.h>
  14 #include <linux/errno.h>
  15 #include <linux/err.h>
  16 #include <linux/string.h>
  17 #include <linux/clk.h>
  18 #include <linux/mutex.h>
  19
  20 #include <asm/hardware/icst525.h>
  21
  22 #include "clock.h"
  23
  24 static LIST_HEAD(clocks);
  25 static DEFINE_MUTEX(clocks_mutex);
  26
  27 struct clk *clk_get(struct device *dev, const char *id)
  28 {
  29         struct clk *p, *clk = ERR_PTR(-ENOENT);
  30
  31         mutex_lock(&clocks_mutex);
  32         list_for_each_entry(p, &clocks, node) {
  33                 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  34                         clk = p;
  35                         break;
  36                 }
  37         }
  38         mutex_unlock(&clocks_mutex);
  39
  40         return clk;
  41 }
  42 EXPORT_SYMBOL(clk_get);
  43
  44 void clk_put(struct clk *clk)
  45 {
  46         module_put(clk->owner);
  47 }
  48 EXPORT_SYMBOL(clk_put);
  49
  50 int clk_enable(struct clk *clk)
  51 {
  52         return 0;
  53 }
  54 EXPORT_SYMBOL(clk_enable);
  55
  56 void clk_disable(struct clk *clk)
  57 {
  58 }
  59 EXPORT_SYMBOL(clk_disable);
  60
  61 unsigned long clk_get_rate(struct clk *clk)
  62 {
  63         return clk->rate;
  64 }
  65 EXPORT_SYMBOL(clk_get_rate);
  66
  67 long clk_round_rate(struct clk *clk, unsigned long rate)
  68 {
  69         struct icst525_vco vco;
  70
  71         vco = icst525_khz_to_vco(clk->params, rate / 1000);
  72         return icst525_khz(clk->params, vco) * 1000;
  73 }
  74 EXPORT_SYMBOL(clk_round_rate);
  75
  76 int clk_set_rate(struct clk *clk, unsigned long rate)
  77 {
  78         int ret = -EIO;
  79         if (clk->setvco) {
  80                 struct icst525_vco vco;
  81
  82                 vco = icst525_khz_to_vco(clk->params, rate / 1000);
  83                 clk->rate = icst525_khz(clk->params, vco) * 1000;
  84
  85                 printk("Clock %s: setting VCO reg params: S=%d R=%d V=%d\n",
  86                         clk->name, vco.s, vco.r, vco.v);
  87
  88                 clk->setvco(clk, vco);
  89                 ret = 0;
  90         }
  91         return 0;
  92 }
  93 EXPORT_SYMBOL(clk_set_rate);
  94
  95 /*
  96  * These are fixed clocks.
  97  */
  98 static struct clk kmi_clk = {
  99         .name   = "KMIREFCLK",
 100         .rate   = 24000000,
 101 };
 102
 103 static struct clk uart_clk = {
 104         .name   = "UARTCLK",
 105         .rate   = 14745600,
 106 };
 107
 108 int clk_register(struct clk *clk)
 109 {
 110         mutex_lock(&clocks_mutex);
 111         list_add(&clk->node, &clocks);
 112         mutex_unlock(&clocks_mutex);
 113         return 0;
 114 }
 115 EXPORT_SYMBOL(clk_register);
 116
 117 void clk_unregister(struct clk *clk)
 118 {
 119         mutex_lock(&clocks_mutex);
 120         list_del(&clk->node);
 121         mutex_unlock(&clocks_mutex);
 122 }
 123 EXPORT_SYMBOL(clk_unregister);
 124
 125 static int __init clk_init(void)
 126 {
 127         clk_register(&kmi_clk);
 128         clk_register(&uart_clk);
 129         return 0;
 130 }
 131 arch_initcall(clk_init);