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 asm/hardware/clock.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 (clk->enable)
  64                 ret = clk->enable(clk);
  65         else if (arch_clock->clk_enable)
  66                 ret = arch_clock->clk_enable(clk);
  67         else
  68                 printk(KERN_ERR "Could not enable clock %s\n", clk->name);
  69         spin_unlock_irqrestore(&clockfw_lock, flags);
  70
  71         return ret;
  72 }
  73 EXPORT_SYMBOL(clk_enable);
  74
  75 void clk_disable(struct clk *clk)
  76 {
  77         unsigned long flags;
  78
  79         spin_lock_irqsave(&clockfw_lock, flags);
  80         if (clk->disable)
  81                 clk->disable(clk);
  82         else if (arch_clock->clk_disable)
  83                 arch_clock->clk_disable(clk);
  84         else
  85                 printk(KERN_ERR "Could not disable clock %s\n", clk->name);
  86         spin_unlock_irqrestore(&clockfw_lock, flags);
  87 }
  88 EXPORT_SYMBOL(clk_disable);
  89
  90 int clk_use(struct clk *clk)
  91 {
  92         unsigned long flags;
  93         int ret = 0;
  94
  95         spin_lock_irqsave(&clockfw_lock, flags);
  96         if (arch_clock->clk_use)
  97                 ret = arch_clock->clk_use(clk);
  98         spin_unlock_irqrestore(&clockfw_lock, flags);
  99
 100         return ret;
 101 }
 102 EXPORT_SYMBOL(clk_use);
 103
 104 void clk_unuse(struct clk *clk)
 105 {
 106         unsigned long flags;
 107
 108         spin_lock_irqsave(&clockfw_lock, flags);
 109         if (arch_clock->clk_unuse)
 110                 arch_clock->clk_unuse(clk);
 111         spin_unlock_irqrestore(&clockfw_lock, flags);
 112 }
 113 EXPORT_SYMBOL(clk_unuse);
 114
 115 int clk_get_usecount(struct clk *clk)
 116 {
 117         unsigned long flags;
 118         int ret = 0;
 119
 120         spin_lock_irqsave(&clockfw_lock, flags);
 121         ret = clk->usecount;
 122         spin_unlock_irqrestore(&clockfw_lock, flags);
 123
 124         return ret;
 125 }
 126 EXPORT_SYMBOL(clk_get_usecount);
 127
 128 unsigned long clk_get_rate(struct clk *clk)
 129 {
 130         unsigned long flags;
 131         unsigned long ret = 0;
 132
 133         spin_lock_irqsave(&clockfw_lock, flags);
 134         ret = clk->rate;
 135         spin_unlock_irqrestore(&clockfw_lock, flags);
 136
 137         return ret;
 138 }
 139 EXPORT_SYMBOL(clk_get_rate);
 140
 141 void clk_put(struct clk *clk)
 142 {
 143         if (clk && !IS_ERR(clk))
 144                 module_put(clk->owner);
 145 }
 146 EXPORT_SYMBOL(clk_put);
 147
 148 /*-------------------------------------------------------------------------
 149  * Optional clock functions defined in asm/hardware/clock.h
 150  *-------------------------------------------------------------------------*/
 151
 152 long clk_round_rate(struct clk *clk, unsigned long rate)
 153 {
 154         unsigned long flags;
 155         long ret = 0;
 156
 157         spin_lock_irqsave(&clockfw_lock, flags);
 158         if (arch_clock->clk_round_rate)
 159                 ret = arch_clock->clk_round_rate(clk, rate);
 160         spin_unlock_irqrestore(&clockfw_lock, flags);
 161
 162         return ret;
 163 }
 164 EXPORT_SYMBOL(clk_round_rate);
 165
 166 int clk_set_rate(struct clk *clk, unsigned long rate)
 167 {
 168         unsigned long flags;
 169         int ret = 0;
 170
 171         spin_lock_irqsave(&clockfw_lock, flags);
 172         if (arch_clock->clk_set_rate)
 173                 ret = arch_clock->clk_set_rate(clk, rate);
 174         spin_unlock_irqrestore(&clockfw_lock, flags);
 175
 176         return ret;
 177 }
 178 EXPORT_SYMBOL(clk_set_rate);
 179
 180 int clk_set_parent(struct clk *clk, struct clk *parent)
 181 {
 182         unsigned long flags;
 183         int ret = 0;
 184
 185         spin_lock_irqsave(&clockfw_lock, flags);
 186         if (arch_clock->clk_set_parent)
 187                 ret =  arch_clock->clk_set_parent(clk, parent);
 188         spin_unlock_irqrestore(&clockfw_lock, flags);
 189
 190         return ret;
 191 }
 192 EXPORT_SYMBOL(clk_set_parent);
 193
 194 struct clk *clk_get_parent(struct clk *clk)
 195 {
 196         unsigned long flags;
 197         struct clk * ret = NULL;
 198
 199         spin_lock_irqsave(&clockfw_lock, flags);
 200         if (arch_clock->clk_get_parent)
 201                 ret = arch_clock->clk_get_parent(clk);
 202         spin_unlock_irqrestore(&clockfw_lock, flags);
 203
 204         return ret;
 205 }
 206 EXPORT_SYMBOL(clk_get_parent);
 207
 208 /*-------------------------------------------------------------------------
 209  * OMAP specific clock functions shared between omap1 and omap2
 210  *-------------------------------------------------------------------------*/
 211
 212 unsigned int __initdata mpurate;
 213
 214 /*
 215  * By default we use the rate set by the bootloader.
 216  * You can override this with mpurate= cmdline option.
 217  */
 218 static int __init omap_clk_setup(char *str)
 219 {
 220         get_option(&str, &mpurate);
 221
 222         if (!mpurate)
 223                 return 1;
 224
 225         if (mpurate < 1000)
 226                 mpurate *= 1000000;
 227
 228         return 1;
 229 }
 230 __setup("mpurate=", omap_clk_setup);
 231
 232 /* Used for clocks that always have same value as the parent clock */
 233 void followparent_recalc(struct clk *clk)
 234 {
 235         clk->rate = clk->parent->rate;
 236 }
 237
 238 /* Propagate rate to children */
 239 void propagate_rate(struct clk * tclk)
 240 {
 241         struct clk *clkp;
 242
 243         list_for_each_entry(clkp, &clocks, node) {
 244                 if (likely(clkp->parent != tclk))
 245                         continue;
 246                 if (likely((u32)clkp->recalc))
 247                         clkp->recalc(clkp);
 248         }
 249 }
 250
 251 int clk_register(struct clk *clk)
 252 {
 253         mutex_lock(&clocks_mutex);
 254         list_add(&clk->node, &clocks);
 255         if (clk->init)
 256                 clk->init(clk);
 257         mutex_unlock(&clocks_mutex);
 258
 259         return 0;
 260 }
 261 EXPORT_SYMBOL(clk_register);
 262
 263 void clk_unregister(struct clk *clk)
 264 {
 265         mutex_lock(&clocks_mutex);
 266         list_del(&clk->node);
 267         mutex_unlock(&clocks_mutex);
 268 }
 269 EXPORT_SYMBOL(clk_unregister);
 270
 271 void clk_deny_idle(struct clk *clk)
 272 {
 273         unsigned long flags;
 274
 275         spin_lock_irqsave(&clockfw_lock, flags);
 276         if (arch_clock->clk_deny_idle)
 277                 arch_clock->clk_deny_idle(clk);
 278         spin_unlock_irqrestore(&clockfw_lock, flags);
 279 }
 280 EXPORT_SYMBOL(clk_deny_idle);
 281
 282 void clk_allow_idle(struct clk *clk)
 283 {
 284         unsigned long flags;
 285
 286         spin_lock_irqsave(&clockfw_lock, flags);
 287         if (arch_clock->clk_allow_idle)
 288                 arch_clock->clk_allow_idle(clk);
 289         spin_unlock_irqrestore(&clockfw_lock, flags);
 290 }
 291 EXPORT_SYMBOL(clk_allow_idle);
 292
 293 /*-------------------------------------------------------------------------*/
 294
 295 int __init clk_init(struct clk_functions * custom_clocks)
 296 {
 297         if (!custom_clocks) {
 298                 printk(KERN_ERR "No custom clock functions registered\n");
 299                 BUG();
 300         }
 301
 302         arch_clock = custom_clocks;
 303
 304         return 0;
 305 }