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 #include <linux/cpufreq.h>
  25
  26 #include <asm/io.h>
  27
  28 #include <asm/arch/clock.h>
  29
  30 static LIST_HEAD(clocks);
  31 static DEFINE_MUTEX(clocks_mutex);
  32 static DEFINE_SPINLOCK(clockfw_lock);
  33
  34 static struct clk_functions *arch_clock;
  35
  36 #ifdef CONFIG_PM_DEBUG
  37
  38 static void print_parents(struct clk *clk)
  39 {
  40         struct clk *p;
  41         int printed = 0;
  42
  43         list_for_each_entry(p, &clocks, node) {
  44                 if (p->parent == clk && p->usecount) {
  45                         if (!clk->usecount && !printed) {
  46                                 printk("MISMATCH: %s\n", clk->name);
  47                                 printed = 1;
  48                         }
  49                         printk("\t%-15s\n", p->name);
  50                 }
  51         }
  52 }
  53
  54 void clk_print_usecounts(void)
  55 {
  56         unsigned long flags;
  57         struct clk *p;
  58
  59         spin_lock_irqsave(&clockfw_lock, flags);
  60         list_for_each_entry(p, &clocks, node) {
  61                 if (p->usecount)
  62                         printk("%-15s: %d\n", p->name, p->usecount);
  63                 print_parents(p);
  64
  65         }
  66         spin_unlock_irqrestore(&clockfw_lock, flags);
  67 }
  68
  69 #endif
  70
  71 /*-------------------------------------------------------------------------
  72  * Standard clock functions defined in include/linux/clk.h
  73  *-------------------------------------------------------------------------*/
  74
  75 /*
  76  * Returns a clock. Note that we first try to use device id on the bus
  77  * and clock name. If this fails, we try to use clock name only.
  78  */
  79 struct clk * clk_get(struct device *dev, const char *id)
  80 {
  81         struct clk *p, *clk = ERR_PTR(-ENOENT);
  82         int idno;
  83
  84         if (dev == NULL || dev->bus != &platform_bus_type)
  85                 idno = -1;
  86         else
  87                 idno = to_platform_device(dev)->id;
  88
  89         mutex_lock(&clocks_mutex);
  90
  91         list_for_each_entry(p, &clocks, node) {
  92                 if (p->id == idno &&
  93                     strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  94                         clk = p;
  95                         goto found;
  96                 }
  97         }
  98
  99         list_for_each_entry(p, &clocks, node) {
 100                 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
 101                         clk = p;
 102                         break;
 103                 }
 104         }
 105
 106 found:
 107         mutex_unlock(&clocks_mutex);
 108
 109         return clk;
 110 }
 111 EXPORT_SYMBOL(clk_get);
 112
 113 int clk_enable(struct clk *clk)
 114 {
 115         unsigned long flags;
 116         int ret = 0;
 117
 118         if (clk == NULL || IS_ERR(clk))
 119                 return -EINVAL;
 120
 121         spin_lock_irqsave(&clockfw_lock, flags);
 122         if (arch_clock->clk_enable)
 123                 ret = arch_clock->clk_enable(clk);
 124         spin_unlock_irqrestore(&clockfw_lock, flags);
 125
 126         return ret;
 127 }
 128 EXPORT_SYMBOL(clk_enable);
 129
 130 void clk_disable(struct clk *clk)
 131 {
 132         unsigned long flags;
 133
 134         if (clk == NULL || IS_ERR(clk))
 135                 return;
 136
 137         spin_lock_irqsave(&clockfw_lock, flags);
 138         if (clk->usecount == 0) {
 139                 printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
 140                        clk->name);
 141                 WARN_ON(1);
 142                 goto out;
 143         }
 144
 145         if (arch_clock->clk_disable)
 146                 arch_clock->clk_disable(clk);
 147
 148 out:
 149         spin_unlock_irqrestore(&clockfw_lock, flags);
 150 }
 151 EXPORT_SYMBOL(clk_disable);
 152
 153 int clk_get_usecount(struct clk *clk)
 154 {
 155         unsigned long flags;
 156         int ret = 0;
 157
 158         if (clk == NULL || IS_ERR(clk))
 159                 return 0;
 160
 161         spin_lock_irqsave(&clockfw_lock, flags);
 162         ret = clk->usecount;
 163         spin_unlock_irqrestore(&clockfw_lock, flags);
 164
 165         return ret;
 166 }
 167 EXPORT_SYMBOL(clk_get_usecount);
 168
 169 unsigned long clk_get_rate(struct clk *clk)
 170 {
 171         unsigned long flags;
 172         unsigned long ret = 0;
 173
 174         if (clk == NULL || IS_ERR(clk))
 175                 return 0;
 176
 177         spin_lock_irqsave(&clockfw_lock, flags);
 178         ret = clk->rate;
 179         spin_unlock_irqrestore(&clockfw_lock, flags);
 180
 181         return ret;
 182 }
 183 EXPORT_SYMBOL(clk_get_rate);
 184
 185 void clk_put(struct clk *clk)
 186 {
 187         if (clk && !IS_ERR(clk))
 188                 module_put(clk->owner);
 189 }
 190 EXPORT_SYMBOL(clk_put);
 191
 192 /*-------------------------------------------------------------------------
 193  * Optional clock functions defined in include/linux/clk.h
 194  *-------------------------------------------------------------------------*/
 195
 196 long clk_round_rate(struct clk *clk, unsigned long rate)
 197 {
 198         unsigned long flags;
 199         long ret = 0;
 200
 201         if (clk == NULL || IS_ERR(clk))
 202                 return ret;
 203
 204         spin_lock_irqsave(&clockfw_lock, flags);
 205         if (arch_clock->clk_round_rate)
 206                 ret = arch_clock->clk_round_rate(clk, rate);
 207         spin_unlock_irqrestore(&clockfw_lock, flags);
 208
 209         return ret;
 210 }
 211 EXPORT_SYMBOL(clk_round_rate);
 212
 213 int clk_set_rate(struct clk *clk, unsigned long rate)
 214 {
 215         unsigned long flags;
 216         int ret = -EINVAL;
 217
 218         if (clk == NULL || IS_ERR(clk))
 219                 return ret;
 220
 221         spin_lock_irqsave(&clockfw_lock, flags);
 222         if (arch_clock->clk_set_rate)
 223                 ret = arch_clock->clk_set_rate(clk, rate);
 224         spin_unlock_irqrestore(&clockfw_lock, flags);
 225
 226         return ret;
 227 }
 228 EXPORT_SYMBOL(clk_set_rate);
 229
 230 int clk_set_parent(struct clk *clk, struct clk *parent)
 231 {
 232         unsigned long flags;
 233         int ret = -EINVAL;
 234
 235         if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
 236                 return ret;
 237
 238         spin_lock_irqsave(&clockfw_lock, flags);
 239         if (arch_clock->clk_set_parent)
 240                 ret =  arch_clock->clk_set_parent(clk, parent);
 241         spin_unlock_irqrestore(&clockfw_lock, flags);
 242
 243         return ret;
 244 }
 245 EXPORT_SYMBOL(clk_set_parent);
 246
 247 struct clk *clk_get_parent(struct clk *clk)
 248 {
 249         unsigned long flags;
 250         struct clk * ret = NULL;
 251
 252         if (clk == NULL || IS_ERR(clk))
 253                 return ret;
 254
 255         spin_lock_irqsave(&clockfw_lock, flags);
 256         if (arch_clock->clk_get_parent)
 257                 ret = arch_clock->clk_get_parent(clk);
 258         spin_unlock_irqrestore(&clockfw_lock, flags);
 259
 260         return ret;
 261 }
 262 EXPORT_SYMBOL(clk_get_parent);
 263
 264 /*-------------------------------------------------------------------------
 265  * OMAP specific clock functions shared between omap1 and omap2
 266  *-------------------------------------------------------------------------*/
 267
 268 unsigned int __initdata mpurate;
 269
 270 /*
 271  * By default we use the rate set by the bootloader.
 272  * You can override this with mpurate= cmdline option.
 273  */
 274 static int __init omap_clk_setup(char *str)
 275 {
 276         get_option(&str, &mpurate);
 277
 278         if (!mpurate)
 279                 return 1;
 280
 281         if (mpurate < 1000)
 282                 mpurate *= 1000000;
 283
 284         return 1;
 285 }
 286 __setup("mpurate=", omap_clk_setup);
 287
 288 /* Used for clocks that always have same value as the parent clock */
 289 void followparent_recalc(struct clk *clk)
 290 {
 291         if (clk == NULL || IS_ERR(clk))
 292                 return;
 293
 294         clk->rate = clk->parent->rate;
 295         if (unlikely(clk->flags & RATE_PROPAGATES))
 296                 propagate_rate(clk);
 297 }
 298
 299 /* Propagate rate to children */
 300 void propagate_rate(struct clk * tclk)
 301 {
 302         struct clk *clkp;
 303
 304         if (tclk == NULL || IS_ERR(tclk))
 305                 return;
 306
 307         list_for_each_entry(clkp, &clocks, node) {
 308                 if (likely(clkp->parent != tclk))
 309                         continue;
 310                 if (likely((u32)clkp->recalc))
 311                         clkp->recalc(clkp);
 312         }
 313 }
 314
 315 /**
 316  * recalculate_root_clocks - recalculate and propagate all root clocks
 317  *
 318  * Recalculates all root clocks (clocks with no parent), which if the
 319  * clock's .recalc is set correctly, should also propagate their rates.
 320  * Called at init.
 321  */
 322 void recalculate_root_clocks(void)
 323 {
 324         struct clk *clkp;
 325
 326         list_for_each_entry(clkp, &clocks, node) {
 327                 if (unlikely(!clkp->parent) && likely((u32)clkp->recalc))
 328                         clkp->recalc(clkp);
 329         }
 330 }
 331
 332 int clk_register(struct clk *clk)
 333 {
 334         if (clk == NULL || IS_ERR(clk))
 335                 return -EINVAL;
 336
 337         mutex_lock(&clocks_mutex);
 338         list_add(&clk->node, &clocks);
 339         if (clk->init)
 340                 clk->init(clk);
 341         mutex_unlock(&clocks_mutex);
 342
 343         return 0;
 344 }
 345 EXPORT_SYMBOL(clk_register);
 346
 347 void clk_unregister(struct clk *clk)
 348 {
 349         if (clk == NULL || IS_ERR(clk))
 350                 return;
 351
 352         mutex_lock(&clocks_mutex);
 353         list_del(&clk->node);
 354         mutex_unlock(&clocks_mutex);
 355 }
 356 EXPORT_SYMBOL(clk_unregister);
 357
 358 void clk_deny_idle(struct clk *clk)
 359 {
 360         unsigned long flags;
 361
 362         if (clk == NULL || IS_ERR(clk))
 363                 return;
 364
 365         spin_lock_irqsave(&clockfw_lock, flags);
 366         if (arch_clock->clk_deny_idle)
 367                 arch_clock->clk_deny_idle(clk);
 368         spin_unlock_irqrestore(&clockfw_lock, flags);
 369 }
 370 EXPORT_SYMBOL(clk_deny_idle);
 371
 372 void clk_allow_idle(struct clk *clk)
 373 {
 374         unsigned long flags;
 375
 376         if (clk == NULL || IS_ERR(clk))
 377                 return;
 378
 379         spin_lock_irqsave(&clockfw_lock, flags);
 380         if (arch_clock->clk_allow_idle)
 381                 arch_clock->clk_allow_idle(clk);
 382         spin_unlock_irqrestore(&clockfw_lock, flags);
 383 }
 384 EXPORT_SYMBOL(clk_allow_idle);
 385
 386 void clk_enable_init_clocks(void)
 387 {
 388         struct clk *clkp;
 389
 390         list_for_each_entry(clkp, &clocks, node) {
 391                 if (clkp->flags & ENABLE_ON_INIT)
 392                         clk_enable(clkp);
 393         }
 394 }
 395 EXPORT_SYMBOL(clk_enable_init_clocks);
 396
 397 #ifdef CONFIG_CPU_FREQ
 398 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
 399 {
 400         unsigned long flags;
 401
 402         spin_lock_irqsave(&clockfw_lock, flags);
 403         if (arch_clock->clk_init_cpufreq_table)
 404                 arch_clock->clk_init_cpufreq_table(table);
 405         spin_unlock_irqrestore(&clockfw_lock, flags);
 406 }
 407 EXPORT_SYMBOL(clk_init_cpufreq_table);
 408 #endif
 409
 410 /*-------------------------------------------------------------------------*/
 411
 412 #ifdef CONFIG_OMAP_RESET_CLOCKS
 413 /*
 414  * Disable any unused clocks left on by the bootloader
 415  */
 416 static int __init clk_disable_unused(void)
 417 {
 418         struct clk *ck;
 419         unsigned long flags;
 420
 421         list_for_each_entry(ck, &clocks, node) {
 422                 if (ck->usecount > 0 || (ck->flags & ALWAYS_ENABLED) ||
 423                         ck->enable_reg == 0)
 424                         continue;
 425
 426                 spin_lock_irqsave(&clockfw_lock, flags);
 427                 if (arch_clock->clk_disable_unused)
 428                         arch_clock->clk_disable_unused(ck);
 429                 spin_unlock_irqrestore(&clockfw_lock, flags);
 430         }
 431
 432         return 0;
 433 }
 434 late_initcall(clk_disable_unused);
 435 #endif
 436
 437 int __init clk_init(struct clk_functions * custom_clocks)
 438 {
 439         if (!custom_clocks) {
 440                 printk(KERN_ERR "No custom clock functions registered\n");
 441                 BUG();
 442         }
 443
 444         arch_clock = custom_clocks;
 445
 446         return 0;
 447 }
 448