arch/arm/plat-omap/clock.c

   1 /*
   2  *  linux/arch/arm/plat-omap/clock.c
   3  *
   4  *  Copyright (C) 2004 - 2005 Nokia corporation
   5  *  Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
   6  *
   7  *  Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13 #include <linux/version.h>
  14 #include <linux/config.h>
  15 #include <linux/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/list.h>
  19 #include <linux/errno.h>
  20 #include <linux/err.h>
  21 #include <linux/string.h>
  22 #include <linux/clk.h>
  23 #include <linux/mutex.h>
  24
  25 #include <asm/io.h>
  26 #include <asm/semaphore.h>
  27
  28 #include <asm/arch/clock.h>
  29
  30 LIST_HEAD(clocks);
  31 static DEFINE_MUTEX(clocks_mutex);
  32 DEFINE_SPINLOCK(clockfw_lock);
  33
  34 static struct clk_functions *arch_clock;
  35
  36 /*-------------------------------------------------------------------------
  37  * Standard clock functions defined in include/linux/clk.h
  38  *-------------------------------------------------------------------------*/
  39
  40 struct clk * clk_get(struct device *dev, const char *id)
  41 {
  42         struct clk *p, *clk = ERR_PTR(-ENOENT);
  43
  44         mutex_lock(&clocks_mutex);
  45         list_for_each_entry(p, &clocks, node) {
  46                 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  47                         clk = p;
  48                         break;
  49                 }
  50         }
  51         mutex_unlock(&clocks_mutex);
  52
  53         return clk;
  54 }
  55 EXPORT_SYMBOL(clk_get);
  56
  57 int clk_enable(struct clk *clk)
  58 {
  59         unsigned long flags;
  60         int ret = 0;
  61
  62         spin_lock_irqsave(&clockfw_lock, flags);
  63         if (arch_clock->clk_enable)
  64                 ret = arch_clock->clk_enable(clk);
  65         spin_unlock_irqrestore(&clockfw_lock, flags);
  66
  67         return ret;
  68 }
  69 EXPORT_SYMBOL(clk_enable);
  70
  71 void clk_disable(struct clk *clk)
  72 {
  73         unsigned long flags;
  74
  75         spin_lock_irqsave(&clockfw_lock, flags);
  76         if (arch_clock->clk_disable)
  77                 arch_clock->clk_disable(clk);
  78         spin_unlock_irqrestore(&clockfw_lock, flags);
  79 }
  80 EXPORT_SYMBOL(clk_disable);
  81
  82 int clk_get_usecount(struct clk *clk)
  83 {
  84         unsigned long flags;
  85         int ret = 0;
  86
  87         spin_lock_irqsave(&clockfw_lock, flags);
  88         ret = clk->usecount;
  89         spin_unlock_irqrestore(&clockfw_lock, flags);
  90
  91         return ret;
  92 }
  93 EXPORT_SYMBOL(clk_get_usecount);
  94
  95 unsigned long clk_get_rate(struct clk *clk)
  96 {
  97         unsigned long flags;
  98         unsigned long ret = 0;
  99
 100         spin_lock_irqsave(&clockfw_lock, flags);
 101         ret = clk->rate;
 102         spin_unlock_irqrestore(&clockfw_lock, flags);
 103
 104         return ret;
 105 }
 106 EXPORT_SYMBOL(clk_get_rate);
 107
 108 void clk_put(struct clk *clk)
 109 {
 110         if (clk && !IS_ERR(clk))
 111                 module_put(clk->owner);
 112 }
 113 EXPORT_SYMBOL(clk_put);
 114
 115 /*-------------------------------------------------------------------------
 116  * Optional clock functions defined in include/linux/clk.h
 117  *-------------------------------------------------------------------------*/
 118
 119 long clk_round_rate(struct clk *clk, unsigned long rate)
 120 {
 121         unsigned long flags;
 122         long ret = 0;
 123
 124         spin_lock_irqsave(&clockfw_lock, flags);
 125         if (arch_clock->clk_round_rate)
 126                 ret = arch_clock->clk_round_rate(clk, rate);
 127         spin_unlock_irqrestore(&clockfw_lock, flags);
 128
 129         return ret;
 130 }
 131 EXPORT_SYMBOL(clk_round_rate);
 132
 133 int clk_set_rate(struct clk *clk, unsigned long rate)
 134 {
 135         unsigned long flags;
 136         int ret = 0;
 137
 138         spin_lock_irqsave(&clockfw_lock, flags);
 139         if (arch_clock->clk_set_rate)
 140                 ret = arch_clock->clk_set_rate(clk, rate);
 141         spin_unlock_irqrestore(&clockfw_lock, flags);
 142
 143         return ret;
 144 }
 145 EXPORT_SYMBOL(clk_set_rate);
 146
 147 int clk_set_parent(struct clk *clk, struct clk *parent)
 148 {
 149         unsigned long flags;
 150         int ret = 0;
 151
 152         spin_lock_irqsave(&clockfw_lock, flags);
 153         if (arch_clock->clk_set_parent)
 154                 ret =  arch_clock->clk_set_parent(clk, parent);
 155         spin_unlock_irqrestore(&clockfw_lock, flags);
 156
 157         return ret;
 158 }
 159 EXPORT_SYMBOL(clk_set_parent);
 160
 161 struct clk *clk_get_parent(struct clk *clk)
 162 {
 163         unsigned long flags;
 164         struct clk * ret = NULL;
 165
 166         spin_lock_irqsave(&clockfw_lock, flags);
 167         if (arch_clock->clk_get_parent)
 168                 ret = arch_clock->clk_get_parent(clk);
 169         spin_unlock_irqrestore(&clockfw_lock, flags);
 170
 171         return ret;
 172 }
 173 EXPORT_SYMBOL(clk_get_parent);
 174
 175 /*-------------------------------------------------------------------------
 176  * OMAP specific clock functions shared between omap1 and omap2
 177  *-------------------------------------------------------------------------*/
 178
 179 unsigned int __initdata mpurate;
 180
 181 /*
 182  * By default we use the rate set by the bootloader.
 183  * You can override this with mpurate= cmdline option.
 184  */
 185 static int __init omap_clk_setup(char *str)
 186 {
 187         get_option(&str, &mpurate);
 188
 189         if (!mpurate)
 190                 return 1;
 191
 192         if (mpurate < 1000)
 193                 mpurate *= 1000000;
 194
 195         return 1;
 196 }
 197 __setup("mpurate=", omap_clk_setup);
 198
 199 /* Used for clocks that always have same value as the parent clock */
 200 void followparent_recalc(struct clk *clk)
 201 {
 202         clk->rate = clk->parent->rate;
 203 }
 204
 205 /* Propagate rate to children */
 206 void propagate_rate(struct clk * tclk)
 207 {
 208         struct clk *clkp;
 209
 210         list_for_each_entry(clkp, &clocks, node) {
 211                 if (likely(clkp->parent != tclk))
 212                         continue;
 213                 if (likely((u32)clkp->recalc))
 214                         clkp->recalc(clkp);
 215         }
 216 }
 217
 218 int clk_register(struct clk *clk)
 219 {
 220         mutex_lock(&clocks_mutex);
 221         list_add(&clk->node, &clocks);
 222         if (clk->init)
 223                 clk->init(clk);
 224         mutex_unlock(&clocks_mutex);
 225
 226         return 0;
 227 }
 228 EXPORT_SYMBOL(clk_register);
 229
 230 void clk_unregister(struct clk *clk)
 231 {
 232         mutex_lock(&clocks_mutex);
 233         list_del(&clk->node);
 234         mutex_unlock(&clocks_mutex);
 235 }
 236 EXPORT_SYMBOL(clk_unregister);
 237
 238 void clk_deny_idle(struct clk *clk)
 239 {
 240         unsigned long flags;
 241
 242         spin_lock_irqsave(&clockfw_lock, flags);
 243         if (arch_clock->clk_deny_idle)
 244                 arch_clock->clk_deny_idle(clk);
 245         spin_unlock_irqrestore(&clockfw_lock, flags);
 246 }
 247 EXPORT_SYMBOL(clk_deny_idle);
 248
 249 void clk_allow_idle(struct clk *clk)
 250 {
 251         unsigned long flags;
 252
 253         spin_lock_irqsave(&clockfw_lock, flags);
 254         if (arch_clock->clk_allow_idle)
 255                 arch_clock->clk_allow_idle(clk);
 256         spin_unlock_irqrestore(&clockfw_lock, flags);
 257 }
 258 EXPORT_SYMBOL(clk_allow_idle);
 259
 260 /*-------------------------------------------------------------------------*/
 261
 262 int __init clk_init(struct clk_functions * custom_clocks)
 263 {
 264         if (!custom_clocks) {
 265                 printk(KERN_ERR "No custom clock functions registered\n");
 266                 BUG();
 267         }
 268
 269         arch_clock = custom_clocks;
 270
 271         return 0;
 272 }