release/src-rt-6.x.4708/linux/linux-2.6.36/arch/arm/mach-mmp/clock.c

   1 /*
   2  *  linux/arch/arm/mach-mmp/clock.c
   3  *
   4  *  This program is free software; you can redistribute it and/or modify
   5  *  it under the terms of the GNU General Public License version 2 as
   6  *  published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/kernel.h>
  11 #include <linux/list.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/clk.h>
  14 #include <linux/io.h>
  15
  16 #include <mach/regs-apbc.h>
  17 #include "clock.h"
  18
  19 static void apbc_clk_enable(struct clk *clk)
  20 {
  21         uint32_t clk_rst;
  22
  23         clk_rst = APBC_APBCLK | APBC_FNCLK | APBC_FNCLKSEL(clk->fnclksel);
  24         __raw_writel(clk_rst, clk->clk_rst);
  25 }
  26
  27 static void apbc_clk_disable(struct clk *clk)
  28 {
  29         __raw_writel(0, clk->clk_rst);
  30 }
  31
  32 struct clkops apbc_clk_ops = {
  33         .enable         = apbc_clk_enable,
  34         .disable        = apbc_clk_disable,
  35 };
  36
  37 static void apmu_clk_enable(struct clk *clk)
  38 {
  39         __raw_writel(clk->enable_val, clk->clk_rst);
  40 }
  41
  42 static void apmu_clk_disable(struct clk *clk)
  43 {
  44         __raw_writel(0, clk->clk_rst);
  45 }
  46
  47 struct clkops apmu_clk_ops = {
  48         .enable         = apmu_clk_enable,
  49         .disable        = apmu_clk_disable,
  50 };
  51
  52 static DEFINE_SPINLOCK(clocks_lock);
  53
  54 int clk_enable(struct clk *clk)
  55 {
  56         unsigned long flags;
  57
  58         spin_lock_irqsave(&clocks_lock, flags);
  59         if (clk->enabled++ == 0)
  60                 clk->ops->enable(clk);
  61         spin_unlock_irqrestore(&clocks_lock, flags);
  62         return 0;
  63 }
  64 EXPORT_SYMBOL(clk_enable);
  65
  66 void clk_disable(struct clk *clk)
  67 {
  68         unsigned long flags;
  69
  70         WARN_ON(clk->enabled == 0);
  71
  72         spin_lock_irqsave(&clocks_lock, flags);
  73         if (--clk->enabled == 0)
  74                 clk->ops->disable(clk);
  75         spin_unlock_irqrestore(&clocks_lock, flags);
  76 }
  77 EXPORT_SYMBOL(clk_disable);
  78
  79 unsigned long clk_get_rate(struct clk *clk)
  80 {
  81         unsigned long rate;
  82
  83         if (clk->ops->getrate)
  84                 rate = clk->ops->getrate(clk);
  85         else
  86                 rate = clk->rate;
  87
  88         return rate;
  89 }
  90 EXPORT_SYMBOL(clk_get_rate);