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 #include <linux/platform_device.h>
  13 #include <linux/delay.h>
  14
  15 #include <asm/arch/pxa2xx-regs.h>
  16 #include <asm/arch/pxa2xx-gpio.h>
  17 #include <asm/hardware.h>
  18
  19 #include "devices.h"
  20 #include "generic.h"
  21 #include "clock.h"
  22
  23 static LIST_HEAD(clocks);
  24 static DEFINE_MUTEX(clocks_mutex);
  25 static DEFINE_SPINLOCK(clocks_lock);
  26
  27 static struct clk *clk_lookup(struct device *dev, const char *id)
  28 {
  29         struct clk *p;
  30
  31         list_for_each_entry(p, &clocks, node)
  32                 if (strcmp(id, p->name) == 0 && p->dev == dev)
  33                         return p;
  34
  35         return NULL;
  36 }
  37
  38 struct clk *clk_get(struct device *dev, const char *id)
  39 {
  40         struct clk *p, *clk = ERR_PTR(-ENOENT);
  41
  42         mutex_lock(&clocks_mutex);
  43         p = clk_lookup(dev, id);
  44         if (!p)
  45                 p = clk_lookup(NULL, id);
  46         if (p)
  47                 clk = p;
  48         mutex_unlock(&clocks_mutex);
  49
  50         if (!IS_ERR(clk) && clk->ops == NULL)
  51                 clk = clk->other;
  52
  53         return clk;
  54 }
  55 EXPORT_SYMBOL(clk_get);
  56
  57 void clk_put(struct clk *clk)
  58 {
  59 }
  60 EXPORT_SYMBOL(clk_put);
  61
  62 int clk_enable(struct clk *clk)
  63 {
  64         unsigned long flags;
  65
  66         spin_lock_irqsave(&clocks_lock, flags);
  67         if (clk->enabled++ == 0)
  68                 clk->ops->enable(clk);
  69         spin_unlock_irqrestore(&clocks_lock, flags);
  70
  71         if (clk->delay)
  72                 udelay(clk->delay);
  73
  74         return 0;
  75 }
  76 EXPORT_SYMBOL(clk_enable);
  77
  78 void clk_disable(struct clk *clk)
  79 {
  80         unsigned long flags;
  81
  82         WARN_ON(clk->enabled == 0);
  83
  84         spin_lock_irqsave(&clocks_lock, flags);
  85         if (--clk->enabled == 0)
  86                 clk->ops->disable(clk);
  87         spin_unlock_irqrestore(&clocks_lock, flags);
  88 }
  89 EXPORT_SYMBOL(clk_disable);
  90
  91 unsigned long clk_get_rate(struct clk *clk)
  92 {
  93         unsigned long rate;
  94
  95         rate = clk->rate;
  96         if (clk->ops->getrate)
  97                 rate = clk->ops->getrate(clk);
  98
  99         return rate;
 100 }
 101 EXPORT_SYMBOL(clk_get_rate);
 102
 103
 104 static void clk_gpio27_enable(struct clk *clk)
 105 {
 106         pxa_gpio_mode(GPIO11_3_6MHz_MD);
 107 }
 108
 109 static void clk_gpio27_disable(struct clk *clk)
 110 {
 111 }
 112
 113 static const struct clkops clk_gpio27_ops = {
 114         .enable         = clk_gpio27_enable,
 115         .disable        = clk_gpio27_disable,
 116 };
 117
 118
 119 void clk_cken_enable(struct clk *clk)
 120 {
 121         CKEN |= 1 << clk->cken;
 122 }
 123
 124 void clk_cken_disable(struct clk *clk)
 125 {
 126         CKEN &= ~(1 << clk->cken);
 127 }
 128
 129 const struct clkops clk_cken_ops = {
 130         .enable         = clk_cken_enable,
 131         .disable        = clk_cken_disable,
 132 };
 133
 134 static struct clk common_clks[] = {
 135         {
 136                 .name           = "GPIO27_CLK",
 137                 .ops            = &clk_gpio27_ops,
 138                 .rate           = 3686400,
 139         },
 140 };
 141
 142 void clks_register(struct clk *clks, size_t num)
 143 {
 144         int i;
 145
 146         mutex_lock(&clocks_mutex);
 147         for (i = 0; i < num; i++)
 148                 list_add(&clks[i].node, &clocks);
 149         mutex_unlock(&clocks_mutex);
 150 }
 151
 152 static int __init clk_init(void)
 153 {
 154         clks_register(common_clks, ARRAY_SIZE(common_clks));
 155         return 0;
 156 }
 157 arch_initcall(clk_init);