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 spinlock_t clk_lock = SPIN_LOCK_UNLOCKED;
  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         BUG_ON(clk->users == 0);
  67
  68         if (--clk->users == 0 && clk->mode)
  69                 clk->mode(clk, 0);
  70         if (clk->parent)
  71                 __clk_disable(clk->parent);
  72 }
  73
  74 void clk_disable(struct clk *clk)
  75 {
  76         unsigned long flags;
  77
  78         spin_lock_irqsave(&clk_lock, flags);
  79         __clk_disable(clk);
  80         spin_unlock_irqrestore(&clk_lock, flags);
  81 }
  82 EXPORT_SYMBOL(clk_disable);
  83
  84 unsigned long clk_get_rate(struct clk *clk)
  85 {
  86         unsigned long flags;
  87         unsigned long rate;
  88
  89         spin_lock_irqsave(&clk_lock, flags);
  90         rate = clk->get_rate(clk);
  91         spin_unlock_irqrestore(&clk_lock, flags);
  92
  93         return rate;
  94 }
  95 EXPORT_SYMBOL(clk_get_rate);
  96
  97 long clk_round_rate(struct clk *clk, unsigned long rate)
  98 {
  99         unsigned long flags, actual_rate;
 100
 101         if (!clk->set_rate)
 102                 return -ENOSYS;
 103
 104         spin_lock_irqsave(&clk_lock, flags);
 105         actual_rate = clk->set_rate(clk, rate, 0);
 106         spin_unlock_irqrestore(&clk_lock, flags);
 107
 108         return actual_rate;
 109 }
 110 EXPORT_SYMBOL(clk_round_rate);
 111
 112 int clk_set_rate(struct clk *clk, unsigned long rate)
 113 {
 114         unsigned long flags;
 115         long ret;
 116
 117         if (!clk->set_rate)
 118                 return -ENOSYS;
 119
 120         spin_lock_irqsave(&clk_lock, flags);
 121         ret = clk->set_rate(clk, rate, 1);
 122         spin_unlock_irqrestore(&clk_lock, flags);
 123
 124         return (ret < 0) ? ret : 0;
 125 }
 126 EXPORT_SYMBOL(clk_set_rate);
 127
 128 int clk_set_parent(struct clk *clk, struct clk *parent)
 129 {
 130         unsigned long flags;
 131         int ret;
 132
 133         if (!clk->set_parent)
 134                 return -ENOSYS;
 135
 136         spin_lock_irqsave(&clk_lock, flags);
 137         ret = clk->set_parent(clk, parent);
 138         spin_unlock_irqrestore(&clk_lock, flags);
 139
 140         return ret;
 141 }
 142 EXPORT_SYMBOL(clk_set_parent);
 143
 144 struct clk *clk_get_parent(struct clk *clk)
 145 {
 146         return clk->parent;
 147 }
 148 EXPORT_SYMBOL(clk_get_parent);