kernel/linux/arch/arm/mach-versatile/clock.c

   1 /*
   2  *  linux/arch/arm/mach-versatile/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
  17 #include <asm/semaphore.h>
  18 #include <asm/hardware/clock.h>
  19 #include <asm/hardware/icst525.h>
  20
  21 #include "clock.h"
  22
  23 static LIST_HEAD(clocks);
  24 static DECLARE_MUTEX(clocks_sem);
  25
  26 struct clk *clk_get(struct device *dev, const char *id)
  27 {
  28         struct clk *p, *clk = ERR_PTR(-ENOENT);
  29
  30         down(&clocks_sem);
  31         list_for_each_entry(p, &clocks, node) {
  32                 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  33                         clk = p;
  34                         break;
  35                 }
  36         }
  37         up(&clocks_sem);
  38
  39         return clk;
  40 }
  41 EXPORT_SYMBOL(clk_get);
  42
  43 void clk_put(struct clk *clk)
  44 {
  45         module_put(clk->owner);
  46 }
  47 EXPORT_SYMBOL(clk_put);
  48
  49 int clk_enable(struct clk *clk)
  50 {
  51         return 0;
  52 }
  53 EXPORT_SYMBOL(clk_enable);
  54
  55 void clk_disable(struct clk *clk)
  56 {
  57 }
  58 EXPORT_SYMBOL(clk_disable);
  59
  60 int clk_use(struct clk *clk)
  61 {
  62         return 0;
  63 }
  64 EXPORT_SYMBOL(clk_use);
  65
  66 void clk_unuse(struct clk *clk)
  67 {
  68 }
  69 EXPORT_SYMBOL(clk_unuse);
  70
  71 unsigned long clk_get_rate(struct clk *clk)
  72 {
  73         return clk->rate;
  74 }
  75 EXPORT_SYMBOL(clk_get_rate);
  76
  77 long clk_round_rate(struct clk *clk, unsigned long rate)
  78 {
  79         return rate;
  80 }
  81 EXPORT_SYMBOL(clk_round_rate);
  82
  83 int clk_set_rate(struct clk *clk, unsigned long rate)
  84 {
  85         int ret = -EIO;
  86 #if 0 // Not yet
  87         if (clk->setvco) {
  88                 struct icst525_vco vco;
  89
  90                 vco = icst525_khz_to_vco(clk->params, rate);
  91                 clk->rate = icst525_khz(clk->params, vco);
  92
  93                 printk("Clock %s: setting VCO reg params: S=%d R=%d V=%d\n",
  94                         clk->name, vco.s, vco.r, vco.v);
  95
  96                 clk->setvco(clk, vco);
  97                 ret = 0;
  98         }
  99 #endif
 100         return ret;
 101 }
 102 EXPORT_SYMBOL(clk_set_rate);
 103
 104 /*
 105  * These are fixed clocks.
 106  */
 107 static struct clk kmi_clk = {
 108         .name   = "KMIREFCLK",
 109         .rate   = 24000000,
 110 };
 111
 112 static struct clk uart_clk = {
 113         .name   = "UARTCLK",
 114         .rate   = 24000000,
 115 };
 116
 117 static struct clk mmci_clk = {
 118         .name   = "MCLK",
 119         .rate   = 33000000,
 120 };
 121
 122 int clk_register(struct clk *clk)
 123 {
 124         down(&clocks_sem);
 125         list_add(&clk->node, &clocks);
 126         up(&clocks_sem);
 127         return 0;
 128 }
 129 EXPORT_SYMBOL(clk_register);
 130
 131 void clk_unregister(struct clk *clk)
 132 {
 133         down(&clocks_sem);
 134         list_del(&clk->node);
 135         up(&clocks_sem);
 136 }
 137 EXPORT_SYMBOL(clk_unregister);
 138
 139 static int __init clk_init(void)
 140 {
 141         clk_register(&kmi_clk);
 142         clk_register(&uart_clk);
 143         clk_register(&mmci_clk);
 144         return 0;
 145 }
 146 arch_initcall(clk_init);