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/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/module.h>
  17 #include <linux/list.h>
  18 #include <linux/errno.h>
  19 #include <linux/err.h>
  20 #include <linux/string.h>
  21 #include <linux/clk.h>
  22 #include <linux/mutex.h>
  23 #include <linux/platform_device.h>
  24
  25 #include <asm/io.h>
  26
  27 #include <asm/arch/clock.h>
  28
  29 static LIST_HEAD(clocks);
  30 static DEFINE_MUTEX(clocks_mutex);
  31 static DEFINE_SPINLOCK(clockfw_lock);
  32
  33 static struct clk_functions *arch_clock;
  34
  35 #ifdef CONFIG_PM_DEBUG
  36
  37 static void print_parents(struct clk *clk)
  38 {
  39         struct clk *p;
  40         int printed = 0;
  41
  42         list_for_each_entry(p, &clocks, node) {
  43                 if (p->parent == clk && p->usecount) {
  44                         if (!clk->usecount && !printed) {
  45                                 printk("MISMATCH: %s\n", clk->name);
  46                                 printed = 1;
  47                         }
  48                         printk("\t%-15s\n", p->name);
  49                 }
  50         }
  51 }
  52
  53 void clk_print_usecounts(void)
  54 {
  55         unsigned long flags;
  56         struct clk *p;
  57
  58         spin_lock_irqsave(&clockfw_lock, flags);
  59         list_for_each_entry(p, &clocks, node) {
  60                 if (p->usecount)
  61                         printk("%-15s: %d\n", p->name, p->usecount);
  62                 print_parents(p);
  63
  64         }
  65         spin_unlock_irqrestore(&clockfw_lock, flags);
  66 }
  67
  68 #endif
  69
  70 /*-------------------------------------------------------------------------
  71  * Standard clock functions defined in include/linux/clk.h
  72  *-------------------------------------------------------------------------*/
  73
  74 /*
  75  * Returns a clock. Note that we first try to use device id on the bus
  76  * and clock name. If this fails, we try to use clock name only.
  77  */
  78 struct clk * clk_get(struct device *dev, const char *id)
  79 {
  80         struct clk *p, *clk = ERR_PTR(-ENOENT);
  81         int idno;
  82
  83         if (dev == NULL || dev->bus != &platform_bus_type)
  84                 idno = -1;
  85         else
  86                 idno = to_platform_device(dev)->id;
  87
  88         mutex_lock(&clocks_mutex);
  89
  90         list_for_each_entry(p, &clocks, node) {
  91                 if (p->id == idno &&
  92                     strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  93                         clk = p;
  94                         goto found;
  95                 }
  96         }
  97
  98         list_for_each_entry(p, &clocks, node) {
  99                 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
 100                         clk = p;
 101                         break;
 102                 }
 103         }
 104
 105 found:
 106         mutex_unlock(&clocks_mutex);
 107
 108         return clk;
 109 }
 110 EXPORT_SYMBOL(clk_get);
 111
 112 int clk_enable(struct clk *clk)
 113 {
 114         unsigned long flags;
 115         int ret = 0;
 116
 117         if (clk == NULL || IS_ERR(clk))
 118                 return -EINVAL;
 119
 120         spin_lock_irqsave(&clockfw_lock, flags);
 121         if (arch_clock->clk_enable)
 122                 ret = arch_clock->clk_enable(clk);
 123         spin_unlock_irqrestore(&clockfw_lock, flags);
 124
 125         return ret;
 126 }
 127 EXPORT_SYMBOL(clk_enable);
 128
 129 void clk_disable(struct clk *clk)
 130 {
 131         unsigned long flags;
 132
 133         if (clk == NULL || IS_ERR(clk))
 134                 return;
 135
 136         spin_lock_irqsave(&clockfw_lock, flags);
 137         BUG_ON(clk->usecount == 0);
 138         if (arch_clock->clk_disable)
 139                 arch_clock->clk_disable(clk);
 140         spin_unlock_irqrestore(&clockfw_lock, flags);
 141 }
 142 EXPORT_SYMBOL(clk_disable);
 143
 144 int clk_get_usecount(struct clk *clk)
 145 {
 146         unsigned long flags;
 147         int ret = 0;
 148
 149         if (clk == NULL || IS_ERR(clk))
 150                 return 0;
 151
 152         spin_lock_irqsave(&clockfw_lock, flags);
 153         ret = clk->usecount;
 154         spin_unlock_irqrestore(&clockfw_lock, flags);
 155
 156         return ret;
 157 }
 158 EXPORT_SYMBOL(clk_get_usecount);
 159
 160 unsigned long clk_get_rate(struct clk *clk)
 161 {
 162         unsigned long flags;
 163         unsigned long ret = 0;
 164
 165         if (clk == NULL || IS_ERR(clk))
 166                 return 0;
 167
 168         spin_lock_irqsave(&clockfw_lock, flags);
 169         ret = clk->rate;
 170         spin_unlock_irqrestore(&clockfw_lock, flags);
 171
 172         return ret;
 173 }
 174 EXPORT_SYMBOL(clk_get_rate);
 175
 176 void clk_put(struct clk *clk)
 177 {
 178         if (clk && !IS_ERR(clk))
 179                 module_put(clk->owner);
 180 }
 181 EXPORT_SYMBOL(clk_put);
 182
 183 /*-------------------------------------------------------------------------
 184  * Optional clock functions defined in include/linux/clk.h
 185  *-------------------------------------------------------------------------*/
 186
 187 long clk_round_rate(struct clk *clk, unsigned long rate)
 188 {
 189         unsigned long flags;
 190         long ret = 0;
 191
 192         if (clk == NULL || IS_ERR(clk))
 193                 return ret;
 194
 195         spin_lock_irqsave(&clockfw_lock, flags);
 196         if (arch_clock->clk_round_rate)
 197                 ret = arch_clock->clk_round_rate(clk, rate);
 198         spin_unlock_irqrestore(&clockfw_lock, flags);
 199
 200         return ret;
 201 }
 202 EXPORT_SYMBOL(clk_round_rate);
 203
 204 int clk_set_rate(struct clk *clk, unsigned long rate)
 205 {
 206         unsigned long flags;
 207         int ret = -EINVAL;
 208
 209         if (clk == NULL || IS_ERR(clk))
 210                 return ret;
 211
 212         spin_lock_irqsave(&clockfw_lock, flags);
 213         if (arch_clock->clk_set_rate)
 214                 ret = arch_clock->clk_set_rate(clk, rate);
 215         spin_unlock_irqrestore(&clockfw_lock, flags);
 216
 217         return ret;
 218 }
 219 EXPORT_SYMBOL(clk_set_rate);
 220
 221 int clk_set_parent(struct clk *clk, struct clk *parent)
 222 {
 223         unsigned long flags;
 224         int ret = -EINVAL;
 225
 226         if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
 227                 return ret;
 228
 229         spin_lock_irqsave(&clockfw_lock, flags);
 230         if (arch_clock->clk_set_parent)
 231                 ret =  arch_clock->clk_set_parent(clk, parent);
 232         spin_unlock_irqrestore(&clockfw_lock, flags);
 233
 234         return ret;
 235 }
 236 EXPORT_SYMBOL(clk_set_parent);
 237
 238 struct clk *clk_get_parent(struct clk *clk)
 239 {
 240         unsigned long flags;
 241         struct clk * ret = NULL;
 242
 243         if (clk == NULL || IS_ERR(clk))
 244                 return ret;
 245
 246         spin_lock_irqsave(&clockfw_lock, flags);
 247         if (arch_clock->clk_get_parent)
 248                 ret = arch_clock->clk_get_parent(clk);
 249         spin_unlock_irqrestore(&clockfw_lock, flags);
 250
 251         return ret;
 252 }
 253 EXPORT_SYMBOL(clk_get_parent);
 254
 255 /*-------------------------------------------------------------------------
 256  * OMAP specific clock functions shared between omap1 and omap2
 257  *-------------------------------------------------------------------------*/
 258
 259 unsigned int __initdata mpurate;
 260
 261 /*
 262  * By default we use the rate set by the bootloader.
 263  * You can override this with mpurate= cmdline option.
 264  */
 265 static int __init omap_clk_setup(char *str)
 266 {
 267         get_option(&str, &mpurate);
 268
 269         if (!mpurate)
 270                 return 1;
 271
 272         if (mpurate < 1000)
 273                 mpurate *= 1000000;
 274
 275         return 1;
 276 }
 277 __setup("mpurate=", omap_clk_setup);
 278
 279 /* Used for clocks that always have same value as the parent clock */
 280 void followparent_recalc(struct clk *clk)
 281 {
 282         if (clk == NULL || IS_ERR(clk))
 283                 return;
 284
 285         clk->rate = clk->parent->rate;
 286         if (unlikely(clk->flags & RATE_PROPAGATES))
 287                 propagate_rate(clk);
 288 }
 289
 290 /* Propagate rate to children */
 291 void propagate_rate(struct clk * tclk)
 292 {
 293         struct clk *clkp;
 294
 295         if (tclk == NULL || IS_ERR(tclk))
 296                 return;
 297
 298         list_for_each_entry(clkp, &clocks, node) {
 299                 if (likely(clkp->parent != tclk))
 300                         continue;
 301                 if (likely((u32)clkp->recalc))
 302                         clkp->recalc(clkp);
 303         }
 304 }
 305
 306 /**
 307  * recalculate_root_clocks - recalculate and propagate all root clocks
 308  *
 309  * Recalculates all root clocks (clocks with no parent), which if the
 310  * clock's .recalc is set correctly, should also propagate their rates.
 311  * Called at init.
 312  */
 313 void recalculate_root_clocks(void)
 314 {
 315         struct clk *clkp;
 316
 317         list_for_each_entry(clkp, &clocks, node) {
 318                 if (unlikely(!clkp->parent) && likely((u32)clkp->recalc))
 319                         clkp->recalc(clkp);
 320         }
 321 }
 322
 323 int clk_register(struct clk *clk)
 324 {
 325         if (clk == NULL || IS_ERR(clk))
 326                 return -EINVAL;
 327
 328         mutex_lock(&clocks_mutex);
 329         list_add(&clk->node, &clocks);
 330         if (clk->init)
 331                 clk->init(clk);
 332         mutex_unlock(&clocks_mutex);
 333
 334         return 0;
 335 }
 336 EXPORT_SYMBOL(clk_register);
 337
 338 void clk_unregister(struct clk *clk)
 339 {
 340         if (clk == NULL || IS_ERR(clk))
 341                 return;
 342
 343         mutex_lock(&clocks_mutex);
 344         list_del(&clk->node);
 345         mutex_unlock(&clocks_mutex);
 346 }
 347 EXPORT_SYMBOL(clk_unregister);
 348
 349 void clk_deny_idle(struct clk *clk)
 350 {
 351         unsigned long flags;
 352
 353         if (clk == NULL || IS_ERR(clk))
 354                 return;
 355
 356         spin_lock_irqsave(&clockfw_lock, flags);
 357         if (arch_clock->clk_deny_idle)
 358                 arch_clock->clk_deny_idle(clk);
 359         spin_unlock_irqrestore(&clockfw_lock, flags);
 360 }
 361 EXPORT_SYMBOL(clk_deny_idle);
 362
 363 void clk_allow_idle(struct clk *clk)
 364 {
 365         unsigned long flags;
 366
 367         if (clk == NULL || IS_ERR(clk))
 368                 return;
 369
 370         spin_lock_irqsave(&clockfw_lock, flags);
 371         if (arch_clock->clk_allow_idle)
 372                 arch_clock->clk_allow_idle(clk);
 373         spin_unlock_irqrestore(&clockfw_lock, flags);
 374 }
 375 EXPORT_SYMBOL(clk_allow_idle);
 376
 377 void clk_enable_init_clocks(void)
 378 {
 379         struct clk *clkp;
 380
 381         list_for_each_entry(clkp, &clocks, node) {
 382                 if (clkp->flags & ENABLE_ON_INIT)
 383                         clk_enable(clkp);
 384         }
 385 }
 386 EXPORT_SYMBOL(clk_enable_init_clocks);
 387
 388 #ifdef CONFIG_CPU_FREQ
 389 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
 390 {
 391         unsigned long flags;
 392
 393         spin_lock_irqsave(&clockfw_lock, flags);
 394         if (arch_clock->clk_init_cpufreq_table)
 395                 arch_clock->clk_init_cpufreq_table(table);
 396         spin_unlock_irqrestore(&clockfw_lock, flags);
 397 }
 398 EXPORT_SYMBOL(clk_init_cpufreq_table);
 399 #endif
 400
 401 /*-------------------------------------------------------------------------*/
 402
 403 #ifdef CONFIG_OMAP_RESET_CLOCKS
 404 /*
 405  * Disable any unused clocks left on by the bootloader
 406  */
 407 static int __init clk_disable_unused(void)
 408 {
 409         struct clk *ck;
 410         unsigned long flags;
 411
 412         list_for_each_entry(ck, &clocks, node) {
 413                 if (ck->usecount > 0 || (ck->flags & ALWAYS_ENABLED) ||
 414                         ck->enable_reg == 0)
 415                         continue;
 416
 417                 spin_lock_irqsave(&clockfw_lock, flags);
 418                 if (arch_clock->clk_disable_unused)
 419                         arch_clock->clk_disable_unused(ck);
 420                 spin_unlock_irqrestore(&clockfw_lock, flags);
 421         }
 422
 423         return 0;
 424 }
 425 late_initcall(clk_disable_unused);
 426 #endif
 427
 428 int __init clk_init(struct clk_functions * custom_clocks)
 429 {
 430         if (!custom_clocks) {
 431                 printk(KERN_ERR "No custom clock functions registered\n");
 432                 BUG();
 433         }
 434
 435         arch_clock = custom_clocks;
 436
 437         return 0;
 438 }
 439