arch/avr32/mach-at32ap/clock.c

   1 /*
   2  * Clock management for AT32AP CPUs
   3  *
   4  * Copyright (C) 2006 Atmel Corporation
   5  *
   6  * Based on arch/arm/mach-at91/clock.c
   7  *   Copyright (C) 2005 David Brownell
   8  *   Copyright (C) 2005 Ivan Kokshaysky
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14 #include <linux/clk.h>
  15 #include <linux/err.h>
  16 #include <linux/device.h>
  17 #include <linux/string.h>
  18
  19 #include "clock.h"
  20
  21 static DEFINE_SPINLOCK(clk_lock);
  22
  23 struct clk *clk_get(struct device *dev, const char *id)
  24 {
  25         int i;
  26
  27         for (i = 0; i < at32_nr_clocks; i++) {
  28                 struct clk *clk = at32_clock_list[i];
  29
  30                 if (clk->dev == dev && strcmp(id, clk->name) == 0)
  31                         return clk;
  32         }
  33
  34         return ERR_PTR(-ENOENT);
  35 }
  36 EXPORT_SYMBOL(clk_get);
  37
  38 void clk_put(struct clk *clk)
  39 {
  40         /* clocks are static for now, we can't free them */
  41 }
  42 EXPORT_SYMBOL(clk_put);
  43
  44 static void __clk_enable(struct clk *clk)
  45 {
  46         if (clk->parent)
  47                 __clk_enable(clk->parent);
  48         if (clk->users++ == 0 && clk->mode)
  49                 clk->mode(clk, 1);
  50 }
  51
  52 int clk_enable(struct clk *clk)
  53 {
  54         unsigned long flags;
  55
  56         spin_lock_irqsave(&clk_lock, flags);
  57         __clk_enable(clk);
  58         spin_unlock_irqrestore(&clk_lock, flags);
  59
  60         return 0;
  61 }
  62 EXPORT_SYMBOL(clk_enable);
  63
  64 static void __clk_disable(struct clk *clk)
  65 {
  66         if (clk->users == 0) {
  67                 printk(KERN_ERR "%s: mismatched disable\n", clk->name);
  68                 WARN_ON(1);
  69                 return;
  70         }
  71
  72         if (--clk->users == 0 && clk->mode)
  73                 clk->mode(clk, 0);
  74         if (clk->parent)
  75                 __clk_disable(clk->parent);
  76 }
  77
  78 void clk_disable(struct clk *clk)
  79 {
  80         unsigned long flags;
  81
  82         spin_lock_irqsave(&clk_lock, flags);
  83         __clk_disable(clk);
  84         spin_unlock_irqrestore(&clk_lock, flags);
  85 }
  86 EXPORT_SYMBOL(clk_disable);
  87
  88 unsigned long clk_get_rate(struct clk *clk)
  89 {
  90         unsigned long flags;
  91         unsigned long rate;
  92
  93         spin_lock_irqsave(&clk_lock, flags);
  94         rate = clk->get_rate(clk);
  95         spin_unlock_irqrestore(&clk_lock, flags);
  96
  97         return rate;
  98 }
  99 EXPORT_SYMBOL(clk_get_rate);
 100
 101 long clk_round_rate(struct clk *clk, unsigned long rate)
 102 {
 103         unsigned long flags, actual_rate;
 104
 105         if (!clk->set_rate)
 106                 return -ENOSYS;
 107
 108         spin_lock_irqsave(&clk_lock, flags);
 109         actual_rate = clk->set_rate(clk, rate, 0);
 110         spin_unlock_irqrestore(&clk_lock, flags);
 111
 112         return actual_rate;
 113 }
 114 EXPORT_SYMBOL(clk_round_rate);
 115
 116 int clk_set_rate(struct clk *clk, unsigned long rate)
 117 {
 118         unsigned long flags;
 119         long ret;
 120
 121         if (!clk->set_rate)
 122                 return -ENOSYS;
 123
 124         spin_lock_irqsave(&clk_lock, flags);
 125         ret = clk->set_rate(clk, rate, 1);
 126         spin_unlock_irqrestore(&clk_lock, flags);
 127
 128         return (ret < 0) ? ret : 0;
 129 }
 130 EXPORT_SYMBOL(clk_set_rate);
 131
 132 int clk_set_parent(struct clk *clk, struct clk *parent)
 133 {
 134         unsigned long flags;
 135         int ret;
 136
 137         if (!clk->set_parent)
 138                 return -ENOSYS;
 139
 140         spin_lock_irqsave(&clk_lock, flags);
 141         ret = clk->set_parent(clk, parent);
 142         spin_unlock_irqrestore(&clk_lock, flags);
 143
 144         return ret;
 145 }
 146 EXPORT_SYMBOL(clk_set_parent);
 147
 148 struct clk *clk_get_parent(struct clk *clk)
 149 {
 150         return clk->parent;
 151 }
 152 EXPORT_SYMBOL(clk_get_parent);