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
  18 #include <asm/semaphore.h>
  19 #include <asm/hardware/clock.h>
  20 #include <asm/hardware/icst525.h>
  21
  22 #include "clock.h"
  23
  24 static LIST_HEAD(clocks);
  25 static DECLARE_MUTEX(clocks_sem);
  26
  27 struct clk *clk_get(struct device *dev, const char *id)
  28 {
  29         struct clk *p, *clk = ERR_PTR(-ENOENT);
  30
  31         down(&clocks_sem);
  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         up(&clocks_sem);
  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 int clk_use(struct clk *clk)
  62 {
  63         return 0;
  64 }
  65 EXPORT_SYMBOL(clk_use);
  66
  67 void clk_unuse(struct clk *clk)
  68 {
  69 }
  70 EXPORT_SYMBOL(clk_unuse);
  71
  72 unsigned long clk_get_rate(struct clk *clk)
  73 {
  74         return clk->rate;
  75 }
  76 EXPORT_SYMBOL(clk_get_rate);
  77
  78 long clk_round_rate(struct clk *clk, unsigned long rate)
  79 {
  80         struct icst525_vco vco;
  81
  82         vco = icst525_khz_to_vco(clk->params, rate / 1000);
  83         return icst525_khz(clk->params, vco) * 1000;
  84 }
  85 EXPORT_SYMBOL(clk_round_rate);
  86
  87 int clk_set_rate(struct clk *clk, unsigned long rate)
  88 {
  89         int ret = -EIO;
  90         if (clk->setvco) {
  91                 struct icst525_vco vco;
  92
  93                 vco = icst525_khz_to_vco(clk->params, rate / 1000);
  94                 clk->rate = icst525_khz(clk->params, vco) * 1000;
  95
  96                 printk("Clock %s: setting VCO reg params: S=%d R=%d V=%d\n",
  97                         clk->name, vco.s, vco.r, vco.v);
  98
  99                 clk->setvco(clk, vco);
 100                 ret = 0;
 101         }
 102         return 0;
 103 }
 104 EXPORT_SYMBOL(clk_set_rate);
 105
 106 /*
 107  * These are fixed clocks.
 108  */
 109 static struct clk kmi_clk = {
 110         .name   = "KMIREFCLK",
 111         .rate   = 24000000,
 112 };
 113
 114 static struct clk uart_clk = {
 115         .name   = "UARTCLK",
 116         .rate   = 14745600,
 117 };
 118
 119 int clk_register(struct clk *clk)
 120 {
 121         down(&clocks_sem);
 122         list_add(&clk->node, &clocks);
 123         up(&clocks_sem);
 124         return 0;
 125 }
 126 EXPORT_SYMBOL(clk_register);
 127
 128 void clk_unregister(struct clk *clk)
 129 {
 130         down(&clocks_sem);
 131         list_del(&clk->node);
 132         up(&clocks_sem);
 133 }
 134 EXPORT_SYMBOL(clk_unregister);
 135
 136 static int __init clk_init(void)
 137 {
 138         clk_register(&kmi_clk);
 139         clk_register(&uart_clk);
 140         return 0;
 141 }
 142 arch_initcall(clk_init);