arch/arm/mach-pxa/clock.c

   1 /*
   2  *  linux/arch/arm/mach-sa1100/clock.c
   3  */
   4 #include <linux/module.h>
   5 #include <linux/kernel.h>
   6 #include <linux/list.h>
   7 #include <linux/errno.h>
   8 #include <linux/err.h>
   9 #include <linux/string.h>
  10 #include <linux/clk.h>
  11 #include <linux/spinlock.h>
  12
  13 #include <asm/arch/pxa-regs.h>
  14 #include <asm/hardware.h>
  15 #include <asm/semaphore.h>
  16
  17 #include <asm/arch/clock.h>
  18
  19 static LIST_HEAD(clocks);
  20 static DECLARE_MUTEX(clocks_sem);
  21 static DEFINE_SPINLOCK(clocks_lock);
  22
  23 struct clk *clk_get(struct device *dev, const char *id)
  24 {
  25         struct clk *p, *clk = ERR_PTR(-ENOENT);
  26
  27         down(&clocks_sem);
  28         list_for_each_entry(p, &clocks, node) {
  29                 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  30                         clk = p;
  31                         break;
  32                 }
  33         }
  34         up(&clocks_sem);
  35
  36         return clk;
  37 }
  38 EXPORT_SYMBOL(clk_get);
  39
  40 void clk_put(struct clk *clk)
  41 {
  42         module_put(clk->owner);
  43 }
  44 EXPORT_SYMBOL(clk_put);
  45
  46 int clk_enable(struct clk *clk)
  47 {
  48         unsigned long flags;
  49
  50         spin_lock_irqsave(&clocks_lock, flags);
  51         if (clk->enabled++ == 0)
  52                 clk->enable(clk);
  53         spin_unlock_irqrestore(&clocks_lock, flags);
  54         return 0;
  55 }
  56 EXPORT_SYMBOL(clk_enable);
  57
  58 void clk_disable(struct clk *clk)
  59 {
  60         unsigned long flags;
  61
  62         WARN_ON(clk->enabled == 0);
  63
  64         spin_lock_irqsave(&clocks_lock, flags);
  65         if (--clk->enabled == 0)
  66                 clk->disable(clk);
  67         spin_unlock_irqrestore(&clocks_lock, flags);
  68 }
  69 EXPORT_SYMBOL(clk_disable);
  70
  71 unsigned long clk_get_rate(struct clk *clk)
  72 {
  73         if (clk->rate != 0)
  74                 return clk->rate;
  75
  76         while (clk->parent != NULL && clk->rate == 0)
  77                 clk = clk->parent;
  78
  79         return clk->rate;
  80 }
  81 EXPORT_SYMBOL(clk_get_rate);
  82
  83 struct clk *clk_get_parent(struct clk *clk)
  84 {
  85         return clk->parent;
  86 }
  87 EXPORT_SYMBOL(clk_get_parent);
  88
  89 int clk_set_parent(struct clk *clk, struct clk *parent)
  90 {
  91         down(&clocks_sem);
  92         clk->parent = parent;
  93         up(&clocks_sem);
  94
  95         return 0;
  96 }
  97 EXPORT_SYMBOL(clk_set_parent);
  98
  99
 100 static void clk_gpio27_enable(struct clk *clk)
 101 {
 102         pxa_gpio_mode(GPIO11_3_6MHz_MD);
 103 }
 104
 105 static void clk_gpio27_disable(struct clk *clk)
 106 {
 107 }
 108
 109 static struct clk clk_gpio27 = {
 110         .name           = "GPIO27_CLK",
 111         .rate           = 3686400,
 112         .enable         = clk_gpio27_enable,
 113         .disable        = clk_gpio27_disable,
 114 };
 115
 116 int clk_register(struct clk *clk)
 117 {
 118         down(&clocks_sem);
 119         list_add(&clk->node, &clocks);
 120         up(&clocks_sem);
 121         return 0;
 122 }
 123 EXPORT_SYMBOL(clk_register);
 124
 125 void clk_unregister(struct clk *clk)
 126 {
 127         down(&clocks_sem);
 128         list_del(&clk->node);
 129         up(&clocks_sem);
 130 }
 131 EXPORT_SYMBOL(clk_unregister);
 132
 133 static int __init clk_init(void)
 134 {
 135         clk_register(&clk_gpio27);
 136         return 0;
 137 }
 138 arch_initcall(clk_init);