arch/arm/plat-omap/clock.c

   1 /*
   2  *  linux/arch/arm/plat-omap/clock.c
   3  *
   4  *  Copyright (C) 2004 - 2008 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/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/module.h>
  16 #include <linux/list.h>
  17 #include <linux/errno.h>
  18 #include <linux/err.h>
  19 #include <linux/string.h>
  20 #include <linux/clk.h>
  21 #include <linux/mutex.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/cpufreq.h>
  24 #include <linux/debugfs.h>
  25 #include <linux/io.h>
  26
  27 #include <mach/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 /*-------------------------------------------------------------------------
  36  * Standard clock functions defined in include/linux/clk.h
  37  *-------------------------------------------------------------------------*/
  38
  39 /*
  40  * Returns a clock. Note that we first try to use device id on the bus
  41  * and clock name. If this fails, we try to use clock name only.
  42  */
  43 struct clk * clk_get(struct device *dev, const char *id)
  44 {
  45         struct clk *p, *clk = ERR_PTR(-ENOENT);
  46         int idno;
  47
  48         if (dev == NULL || dev->bus != &platform_bus_type)
  49                 idno = -1;
  50         else
  51                 idno = to_platform_device(dev)->id;
  52
  53         mutex_lock(&clocks_mutex);
  54
  55         list_for_each_entry(p, &clocks, node) {
  56                 if (p->id == idno &&
  57                     strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  58                         clk = p;
  59                         goto found;
  60                 }
  61         }
  62
  63         list_for_each_entry(p, &clocks, node) {
  64                 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  65                         clk = p;
  66                         break;
  67                 }
  68         }
  69
  70 found:
  71         mutex_unlock(&clocks_mutex);
  72
  73         return clk;
  74 }
  75 EXPORT_SYMBOL(clk_get);
  76
  77 int clk_enable(struct clk *clk)
  78 {
  79         unsigned long flags;
  80         int ret = 0;
  81
  82         if (clk == NULL || IS_ERR(clk))
  83                 return -EINVAL;
  84
  85         spin_lock_irqsave(&clockfw_lock, flags);
  86         if (arch_clock->clk_enable) {
  87                 ret = arch_clock->clk_enable(clk);
  88                 if (ret == 0 && clk->flags & RECALC_ON_ENABLE) {
  89                         if (clk->recalc)
  90                                 (*clk->recalc)(clk, clk->parent->rate,
  91                                                CURRENT_RATE);
  92                         if (clk->flags & RATE_PROPAGATES)
  93                                 propagate_rate(clk, CURRENT_RATE);
  94                 }
  95         }
  96
  97         spin_unlock_irqrestore(&clockfw_lock, flags);
  98
  99         return ret;
 100 }
 101 EXPORT_SYMBOL(clk_enable);
 102
 103 void clk_disable(struct clk *clk)
 104 {
 105         unsigned long flags;
 106
 107         if (clk == NULL || IS_ERR(clk))
 108                 return;
 109
 110         spin_lock_irqsave(&clockfw_lock, flags);
 111         if (clk->usecount == 0) {
 112                 printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
 113                        clk->name);
 114                 WARN_ON(1);
 115                 goto out;
 116         }
 117
 118         if (arch_clock->clk_disable) {
 119                 arch_clock->clk_disable(clk);
 120                 if (clk->flags & RECALC_ON_ENABLE) {
 121                         if (clk->recalc)
 122                                 (*clk->recalc)(clk, clk->parent->rate,
 123                                                CURRENT_RATE);
 124                         if (clk->flags & RATE_PROPAGATES)
 125                                 propagate_rate(clk, CURRENT_RATE);
 126                 }
 127         }
 128
 129 out:
 130         spin_unlock_irqrestore(&clockfw_lock, flags);
 131 }
 132 EXPORT_SYMBOL(clk_disable);
 133
 134 int clk_get_usecount(struct clk *clk)
 135 {
 136         unsigned long flags;
 137         int ret = 0;
 138
 139         if (clk == NULL || IS_ERR(clk))
 140                 return 0;
 141
 142         spin_lock_irqsave(&clockfw_lock, flags);
 143         ret = clk->usecount;
 144         spin_unlock_irqrestore(&clockfw_lock, flags);
 145
 146         return ret;
 147 }
 148 EXPORT_SYMBOL(clk_get_usecount);
 149
 150 unsigned long clk_get_rate(struct clk *clk)
 151 {
 152         unsigned long flags;
 153         unsigned long ret = 0;
 154
 155         if (clk == NULL || IS_ERR(clk))
 156                 return 0;
 157
 158         spin_lock_irqsave(&clockfw_lock, flags);
 159         ret = clk->rate;
 160         spin_unlock_irqrestore(&clockfw_lock, flags);
 161
 162         return ret;
 163 }
 164 EXPORT_SYMBOL(clk_get_rate);
 165
 166 void clk_put(struct clk *clk)
 167 {
 168         if (clk && !IS_ERR(clk))
 169                 module_put(clk->owner);
 170 }
 171 EXPORT_SYMBOL(clk_put);
 172
 173 /*-------------------------------------------------------------------------
 174  * Optional clock functions defined in include/linux/clk.h
 175  *-------------------------------------------------------------------------*/
 176
 177 long clk_round_rate(struct clk *clk, unsigned long rate)
 178 {
 179         unsigned long flags;
 180         long ret = 0;
 181
 182         if (clk == NULL || IS_ERR(clk))
 183                 return ret;
 184
 185         spin_lock_irqsave(&clockfw_lock, flags);
 186         if (arch_clock->clk_round_rate)
 187                 ret = arch_clock->clk_round_rate(clk, rate);
 188         spin_unlock_irqrestore(&clockfw_lock, flags);
 189
 190         return ret;
 191 }
 192 EXPORT_SYMBOL(clk_round_rate);
 193
 194 int clk_set_rate(struct clk *clk, unsigned long rate)
 195 {
 196         unsigned long flags;
 197         int ret = -EINVAL;
 198
 199         if (clk == NULL || IS_ERR(clk))
 200                 return ret;
 201
 202         spin_lock_irqsave(&clockfw_lock, flags);
 203
 204         if (arch_clock->clk_set_rate) {
 205                 ret = arch_clock->clk_set_rate(clk, rate);
 206                 if (ret == 0) {
 207                         if (clk->recalc)
 208                                 (*clk->recalc)(clk, clk->parent->rate,
 209                                                CURRENT_RATE);
 210                         if (clk->flags & RATE_PROPAGATES)
 211                                 propagate_rate(clk, CURRENT_RATE);
 212                 }
 213         }
 214
 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
 231         if (arch_clock->clk_set_parent) {
 232                 ret = arch_clock->clk_set_parent(clk, parent);
 233                 if (ret == 0) {
 234                         if (clk->recalc)
 235                                 (*clk->recalc)(clk, clk->parent->rate,
 236                                                CURRENT_RATE);
 237                         if (clk->flags & RATE_PROPAGATES)
 238                                 propagate_rate(clk, CURRENT_RATE);
 239                 }
 240         }
 241
 242         spin_unlock_irqrestore(&clockfw_lock, flags);
 243
 244         return ret;
 245 }
 246 EXPORT_SYMBOL(clk_set_parent);
 247
 248 struct clk *clk_get_parent(struct clk *clk)
 249 {
 250         unsigned long flags;
 251         struct clk * ret = NULL;
 252
 253         if (clk == NULL || IS_ERR(clk))
 254                 return ret;
 255
 256         spin_lock_irqsave(&clockfw_lock, flags);
 257         if (arch_clock->clk_get_parent)
 258                 ret = arch_clock->clk_get_parent(clk);
 259         spin_unlock_irqrestore(&clockfw_lock, flags);
 260
 261         return ret;
 262 }
 263 EXPORT_SYMBOL(clk_get_parent);
 264
 265 /*-------------------------------------------------------------------------
 266  * OMAP specific clock functions shared between omap1 and omap2
 267  *-------------------------------------------------------------------------*/
 268
 269 unsigned int __initdata mpurate;
 270
 271 /*
 272  * By default we use the rate set by the bootloader.
 273  * You can override this with mpurate= cmdline option.
 274  */
 275 static int __init omap_clk_setup(char *str)
 276 {
 277         get_option(&str, &mpurate);
 278
 279         if (!mpurate)
 280                 return 1;
 281
 282         if (mpurate < 1000)
 283                 mpurate *= 1000000;
 284
 285         return 1;
 286 }
 287 __setup("mpurate=", omap_clk_setup);
 288
 289 /* Used for clocks that always have same value as the parent clock */
 290 void followparent_recalc(struct clk *clk, unsigned long new_parent_rate,
 291                          u8 rate_storage)
 292 {
 293         if (rate_storage == CURRENT_RATE)
 294                 clk->rate = new_parent_rate;
 295         else if (rate_storage == TEMP_RATE)
 296                 clk->temp_rate = new_parent_rate;
 297 }
 298
 299 /* Propagate rate to children */
 300 void propagate_rate(struct clk *tclk, u8 rate_storage)
 301 {
 302         struct clk *clkp;
 303         unsigned long parent_rate = 0;
 304
 305         if (tclk == NULL || IS_ERR(tclk))
 306                 return;
 307
 308         list_for_each_entry(clkp, &clocks, node) {
 309                 if (likely(clkp->parent != tclk))
 310                         continue;
 311
 312                 if (rate_storage == CURRENT_RATE)
 313                         parent_rate = tclk->rate;
 314                 else if (rate_storage == TEMP_RATE)
 315                         parent_rate = tclk->temp_rate;
 316
 317                 if (clkp->recalc)
 318                         clkp->recalc(clkp, parent_rate, rate_storage);
 319                 if (clkp->flags & RATE_PROPAGATES)
 320                         propagate_rate(clkp, rate_storage);
 321         }
 322 }
 323
 324 /**
 325  * recalculate_root_clocks - recalculate and propagate all root clocks
 326  *
 327  * Recalculates all root clocks (clocks with no parent), which if the
 328  * clock's .recalc is set correctly, should also propagate their rates.
 329  * Called at init.
 330  */
 331 void recalculate_root_clocks(void)
 332 {
 333         struct clk *clkp;
 334
 335         list_for_each_entry(clkp, &clocks, node) {
 336                 if (unlikely(!clkp->parent)) {
 337                         if (clkp->recalc)
 338                                 clkp->recalc(clkp, 0, CURRENT_RATE);
 339                         if (clkp->flags & RATE_PROPAGATES)
 340                                 propagate_rate(clkp, CURRENT_RATE);
 341                 }
 342         }
 343 }
 344
 345 int clk_register(struct clk *clk)
 346 {
 347         if (clk == NULL || IS_ERR(clk))
 348                 return -EINVAL;
 349
 350         mutex_lock(&clocks_mutex);
 351         list_add(&clk->node, &clocks);
 352         if (clk->init)
 353                 clk->init(clk);
 354         mutex_unlock(&clocks_mutex);
 355
 356         return 0;
 357 }
 358 EXPORT_SYMBOL(clk_register);
 359
 360 void clk_unregister(struct clk *clk)
 361 {
 362         if (clk == NULL || IS_ERR(clk))
 363                 return;
 364
 365         mutex_lock(&clocks_mutex);
 366         list_del(&clk->node);
 367         mutex_unlock(&clocks_mutex);
 368 }
 369 EXPORT_SYMBOL(clk_unregister);
 370
 371 void clk_deny_idle(struct clk *clk)
 372 {
 373         unsigned long flags;
 374
 375         if (clk == NULL || IS_ERR(clk))
 376                 return;
 377
 378         spin_lock_irqsave(&clockfw_lock, flags);
 379         if (arch_clock->clk_deny_idle)
 380                 arch_clock->clk_deny_idle(clk);
 381         spin_unlock_irqrestore(&clockfw_lock, flags);
 382 }
 383 EXPORT_SYMBOL(clk_deny_idle);
 384
 385 void clk_allow_idle(struct clk *clk)
 386 {
 387         unsigned long flags;
 388
 389         if (clk == NULL || IS_ERR(clk))
 390                 return;
 391
 392         spin_lock_irqsave(&clockfw_lock, flags);
 393         if (arch_clock->clk_allow_idle)
 394                 arch_clock->clk_allow_idle(clk);
 395         spin_unlock_irqrestore(&clockfw_lock, flags);
 396 }
 397 EXPORT_SYMBOL(clk_allow_idle);
 398
 399 void clk_enable_init_clocks(void)
 400 {
 401         struct clk *clkp;
 402
 403         list_for_each_entry(clkp, &clocks, node) {
 404                 if (clkp->flags & ENABLE_ON_INIT)
 405                         clk_enable(clkp);
 406         }
 407 }
 408 EXPORT_SYMBOL(clk_enable_init_clocks);
 409
 410 #ifdef CONFIG_CPU_FREQ
 411 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
 412 {
 413         unsigned long flags;
 414
 415         spin_lock_irqsave(&clockfw_lock, flags);
 416         if (arch_clock->clk_init_cpufreq_table)
 417                 arch_clock->clk_init_cpufreq_table(table);
 418         spin_unlock_irqrestore(&clockfw_lock, flags);
 419 }
 420 EXPORT_SYMBOL(clk_init_cpufreq_table);
 421 #endif
 422
 423 /*-------------------------------------------------------------------------*/
 424
 425 #ifdef CONFIG_OMAP_RESET_CLOCKS
 426 /*
 427  * Disable any unused clocks left on by the bootloader
 428  */
 429 static int __init clk_disable_unused(void)
 430 {
 431         struct clk *ck;
 432         unsigned long flags;
 433
 434         list_for_each_entry(ck, &clocks, node) {
 435                 if (ck->usecount > 0 ||
 436                     (ck->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK)))
 437                         continue;
 438
 439                 if (cpu_class_is_omap1() && ck->enable_reg == 0)
 440                         continue;
 441
 442                 spin_lock_irqsave(&clockfw_lock, flags);
 443                 if (arch_clock->clk_disable_unused)
 444                         arch_clock->clk_disable_unused(ck);
 445                 spin_unlock_irqrestore(&clockfw_lock, flags);
 446         }
 447
 448         return 0;
 449 }
 450 late_initcall(clk_disable_unused);
 451 #endif
 452
 453 int __init clk_init(struct clk_functions * custom_clocks)
 454 {
 455         if (!custom_clocks) {
 456                 printk(KERN_ERR "No custom clock functions registered\n");
 457                 BUG();
 458         }
 459
 460         arch_clock = custom_clocks;
 461
 462         return 0;
 463 }
 464
 465 #if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
 466 /*
 467  *      debugfs support to trace clock tree hierarchy and attributes
 468  */
 469 static struct dentry *clk_debugfs_root;
 470
 471 static int clk_debugfs_register_one(struct clk *c)
 472 {
 473         int err;
 474         struct dentry *d, *child;
 475         struct clk *pa = c->parent;
 476         char s[255];
 477         char *p = s;
 478
 479         p += sprintf(p, "%s", c->name);
 480         if (c->id != 0)
 481                 sprintf(p, ":%d", c->id);
 482         d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
 483         if (!d)
 484                 return -ENOMEM;
 485         c->dent = d;
 486
 487         d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
 488         if (!d) {
 489                 err = -ENOMEM;
 490                 goto err_out;
 491         }
 492         d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
 493         if (!d) {
 494                 err = -ENOMEM;
 495                 goto err_out;
 496         }
 497         d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
 498         if (!d) {
 499                 err = -ENOMEM;
 500                 goto err_out;
 501         }
 502         return 0;
 503
 504 err_out:
 505         d = c->dent;
 506         list_for_each_entry(child, &d->d_subdirs, d_u.d_child)
 507                 debugfs_remove(child);
 508         debugfs_remove(c->dent);
 509         return err;
 510 }
 511
 512 static int clk_debugfs_register(struct clk *c)
 513 {
 514         int err;
 515         struct clk *pa = c->parent;
 516
 517         if (pa && !pa->dent) {
 518                 err = clk_debugfs_register(pa);
 519                 if (err)
 520                         return err;
 521         }
 522
 523         if (!c->dent) {
 524                 err = clk_debugfs_register_one(c);
 525                 if (err)
 526                         return err;
 527         }
 528         return 0;
 529 }
 530
 531 static int __init clk_debugfs_init(void)
 532 {
 533         struct clk *c;
 534         struct dentry *d;
 535         int err;
 536
 537         d = debugfs_create_dir("clock", NULL);
 538         if (!d)
 539                 return -ENOMEM;
 540         clk_debugfs_root = d;
 541
 542         list_for_each_entry(c, &clocks, node) {
 543                 err = clk_debugfs_register(c);
 544                 if (err)
 545                         goto err_out;
 546         }
 547         return 0;
 548 err_out:
 549         debugfs_remove(clk_debugfs_root); /* REVISIT: Cleanup correctly */
 550         return err;
 551 }
 552 late_initcall(clk_debugfs_init);
 553
 554 #endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */