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/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 #include <linux/debugfs.h>
  26
  27 #include <asm/io.h>
  28 #include <asm/semaphore.h>
  29
  30 #include <asm/arch/clock.h>
  31
  32 static LIST_HEAD(clocks);
  33 static DEFINE_MUTEX(clocks_mutex);
  34 static DEFINE_SPINLOCK(clockfw_lock);
  35
  36 static struct clk_functions *arch_clock;
  37
  38 /*-------------------------------------------------------------------------
  39  * Standard clock functions defined in include/linux/clk.h
  40  *-------------------------------------------------------------------------*/
  41
  42 /*
  43  * Returns a clock. Note that we first try to use device id on the bus
  44  * and clock name. If this fails, we try to use clock name only.
  45  */
  46 struct clk * clk_get(struct device *dev, const char *id)
  47 {
  48         struct clk *p, *clk = ERR_PTR(-ENOENT);
  49         int idno;
  50
  51         if (dev == NULL || dev->bus != &platform_bus_type)
  52                 idno = -1;
  53         else
  54                 idno = to_platform_device(dev)->id;
  55
  56         mutex_lock(&clocks_mutex);
  57
  58         list_for_each_entry(p, &clocks, node) {
  59                 if (p->id == idno &&
  60                     strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  61                         clk = p;
  62                         goto found;
  63                 }
  64         }
  65
  66         list_for_each_entry(p, &clocks, node) {
  67                 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  68                         clk = p;
  69                         break;
  70                 }
  71         }
  72
  73 found:
  74         mutex_unlock(&clocks_mutex);
  75
  76         return clk;
  77 }
  78 EXPORT_SYMBOL(clk_get);
  79
  80 int clk_enable(struct clk *clk)
  81 {
  82         unsigned long flags;
  83         int ret = 0;
  84
  85         if (clk == NULL || IS_ERR(clk))
  86                 return -EINVAL;
  87
  88         spin_lock_irqsave(&clockfw_lock, flags);
  89         if (arch_clock->clk_enable)
  90                 ret = arch_clock->clk_enable(clk);
  91         spin_unlock_irqrestore(&clockfw_lock, flags);
  92
  93         return ret;
  94 }
  95 EXPORT_SYMBOL(clk_enable);
  96
  97 void clk_disable(struct clk *clk)
  98 {
  99         unsigned long flags;
 100
 101         if (clk == NULL || IS_ERR(clk))
 102                 return;
 103
 104         spin_lock_irqsave(&clockfw_lock, flags);
 105         if (clk->usecount == 0) {
 106                 printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
 107                        clk->name);
 108                 WARN_ON(1);
 109                 goto out;
 110         }
 111
 112         if (arch_clock->clk_disable)
 113                 arch_clock->clk_disable(clk);
 114
 115 out:
 116         spin_unlock_irqrestore(&clockfw_lock, flags);
 117 }
 118 EXPORT_SYMBOL(clk_disable);
 119
 120 int clk_get_usecount(struct clk *clk)
 121 {
 122         unsigned long flags;
 123         int ret = 0;
 124
 125         if (clk == NULL || IS_ERR(clk))
 126                 return 0;
 127
 128         spin_lock_irqsave(&clockfw_lock, flags);
 129         ret = clk->usecount;
 130         spin_unlock_irqrestore(&clockfw_lock, flags);
 131
 132         return ret;
 133 }
 134 EXPORT_SYMBOL(clk_get_usecount);
 135
 136 unsigned long clk_get_rate(struct clk *clk)
 137 {
 138         unsigned long flags;
 139         unsigned long ret = 0;
 140
 141         if (clk == NULL || IS_ERR(clk))
 142                 return 0;
 143
 144         spin_lock_irqsave(&clockfw_lock, flags);
 145         ret = clk->rate;
 146         spin_unlock_irqrestore(&clockfw_lock, flags);
 147
 148         return ret;
 149 }
 150 EXPORT_SYMBOL(clk_get_rate);
 151
 152 void clk_put(struct clk *clk)
 153 {
 154         if (clk && !IS_ERR(clk))
 155                 module_put(clk->owner);
 156 }
 157 EXPORT_SYMBOL(clk_put);
 158
 159 /*-------------------------------------------------------------------------
 160  * Optional clock functions defined in include/linux/clk.h
 161  *-------------------------------------------------------------------------*/
 162
 163 long clk_round_rate(struct clk *clk, unsigned long rate)
 164 {
 165         unsigned long flags;
 166         long ret = 0;
 167
 168         if (clk == NULL || IS_ERR(clk))
 169                 return ret;
 170
 171         spin_lock_irqsave(&clockfw_lock, flags);
 172         if (arch_clock->clk_round_rate)
 173                 ret = arch_clock->clk_round_rate(clk, rate);
 174         spin_unlock_irqrestore(&clockfw_lock, flags);
 175
 176         return ret;
 177 }
 178 EXPORT_SYMBOL(clk_round_rate);
 179
 180 int clk_set_rate(struct clk *clk, unsigned long rate)
 181 {
 182         unsigned long flags;
 183         int ret = -EINVAL;
 184
 185         if (clk == NULL || IS_ERR(clk))
 186                 return ret;
 187
 188         spin_lock_irqsave(&clockfw_lock, flags);
 189         if (arch_clock->clk_set_rate)
 190                 ret = arch_clock->clk_set_rate(clk, rate);
 191         spin_unlock_irqrestore(&clockfw_lock, flags);
 192
 193         return ret;
 194 }
 195 EXPORT_SYMBOL(clk_set_rate);
 196
 197 int clk_set_parent(struct clk *clk, struct clk *parent)
 198 {
 199         unsigned long flags;
 200         int ret = -EINVAL;
 201
 202         if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
 203                 return ret;
 204
 205         spin_lock_irqsave(&clockfw_lock, flags);
 206         if (arch_clock->clk_set_parent)
 207                 ret =  arch_clock->clk_set_parent(clk, parent);
 208         spin_unlock_irqrestore(&clockfw_lock, flags);
 209
 210         return ret;
 211 }
 212 EXPORT_SYMBOL(clk_set_parent);
 213
 214 struct clk *clk_get_parent(struct clk *clk)
 215 {
 216         unsigned long flags;
 217         struct clk * ret = NULL;
 218
 219         if (clk == NULL || IS_ERR(clk))
 220                 return ret;
 221
 222         spin_lock_irqsave(&clockfw_lock, flags);
 223         if (arch_clock->clk_get_parent)
 224                 ret = arch_clock->clk_get_parent(clk);
 225         spin_unlock_irqrestore(&clockfw_lock, flags);
 226
 227         return ret;
 228 }
 229 EXPORT_SYMBOL(clk_get_parent);
 230
 231 /*-------------------------------------------------------------------------
 232  * OMAP specific clock functions shared between omap1 and omap2
 233  *-------------------------------------------------------------------------*/
 234
 235 unsigned int __initdata mpurate;
 236
 237 /*
 238  * By default we use the rate set by the bootloader.
 239  * You can override this with mpurate= cmdline option.
 240  */
 241 static int __init omap_clk_setup(char *str)
 242 {
 243         get_option(&str, &mpurate);
 244
 245         if (!mpurate)
 246                 return 1;
 247
 248         if (mpurate < 1000)
 249                 mpurate *= 1000000;
 250
 251         return 1;
 252 }
 253 __setup("mpurate=", omap_clk_setup);
 254
 255 /* Used for clocks that always have same value as the parent clock */
 256 void followparent_recalc(struct clk *clk)
 257 {
 258         if (clk == NULL || IS_ERR(clk))
 259                 return;
 260
 261         clk->rate = clk->parent->rate;
 262         if (unlikely(clk->flags & RATE_PROPAGATES))
 263                 propagate_rate(clk);
 264 }
 265
 266 /* Propagate rate to children */
 267 void propagate_rate(struct clk * tclk)
 268 {
 269         struct clk *clkp;
 270
 271         if (tclk == NULL || IS_ERR(tclk))
 272                 return;
 273
 274         list_for_each_entry(clkp, &clocks, node) {
 275                 if (likely(clkp->parent != tclk))
 276                         continue;
 277                 if (likely((u32)clkp->recalc))
 278                         clkp->recalc(clkp);
 279         }
 280 }
 281
 282 /**
 283  * recalculate_root_clocks - recalculate and propagate all root clocks
 284  *
 285  * Recalculates all root clocks (clocks with no parent), which if the
 286  * clock's .recalc is set correctly, should also propagate their rates.
 287  * Called at init.
 288  */
 289 void recalculate_root_clocks(void)
 290 {
 291         struct clk *clkp;
 292
 293         list_for_each_entry(clkp, &clocks, node) {
 294                 if (unlikely(!clkp->parent) && likely((u32)clkp->recalc))
 295                         clkp->recalc(clkp);
 296         }
 297 }
 298
 299 int clk_register(struct clk *clk)
 300 {
 301         if (clk == NULL || IS_ERR(clk))
 302                 return -EINVAL;
 303
 304         mutex_lock(&clocks_mutex);
 305         list_add(&clk->node, &clocks);
 306         if (clk->init)
 307                 clk->init(clk);
 308         mutex_unlock(&clocks_mutex);
 309
 310         return 0;
 311 }
 312 EXPORT_SYMBOL(clk_register);
 313
 314 void clk_unregister(struct clk *clk)
 315 {
 316         if (clk == NULL || IS_ERR(clk))
 317                 return;
 318
 319         mutex_lock(&clocks_mutex);
 320         list_del(&clk->node);
 321         mutex_unlock(&clocks_mutex);
 322 }
 323 EXPORT_SYMBOL(clk_unregister);
 324
 325 void clk_deny_idle(struct clk *clk)
 326 {
 327         unsigned long flags;
 328
 329         if (clk == NULL || IS_ERR(clk))
 330                 return;
 331
 332         spin_lock_irqsave(&clockfw_lock, flags);
 333         if (arch_clock->clk_deny_idle)
 334                 arch_clock->clk_deny_idle(clk);
 335         spin_unlock_irqrestore(&clockfw_lock, flags);
 336 }
 337 EXPORT_SYMBOL(clk_deny_idle);
 338
 339 void clk_allow_idle(struct clk *clk)
 340 {
 341         unsigned long flags;
 342
 343         if (clk == NULL || IS_ERR(clk))
 344                 return;
 345
 346         spin_lock_irqsave(&clockfw_lock, flags);
 347         if (arch_clock->clk_allow_idle)
 348                 arch_clock->clk_allow_idle(clk);
 349         spin_unlock_irqrestore(&clockfw_lock, flags);
 350 }
 351 EXPORT_SYMBOL(clk_allow_idle);
 352
 353 void clk_enable_init_clocks(void)
 354 {
 355         struct clk *clkp;
 356
 357         list_for_each_entry(clkp, &clocks, node) {
 358                 if (clkp->flags & ENABLE_ON_INIT)
 359                         clk_enable(clkp);
 360         }
 361 }
 362 EXPORT_SYMBOL(clk_enable_init_clocks);
 363
 364 #ifdef CONFIG_CPU_FREQ
 365 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
 366 {
 367         unsigned long flags;
 368
 369         spin_lock_irqsave(&clockfw_lock, flags);
 370         if (arch_clock->clk_init_cpufreq_table)
 371                 arch_clock->clk_init_cpufreq_table(table);
 372         spin_unlock_irqrestore(&clockfw_lock, flags);
 373 }
 374 EXPORT_SYMBOL(clk_init_cpufreq_table);
 375 #endif
 376
 377 /*-------------------------------------------------------------------------*/
 378
 379 #ifdef CONFIG_OMAP_RESET_CLOCKS
 380 /*
 381  * Disable any unused clocks left on by the bootloader
 382  */
 383 static int __init clk_disable_unused(void)
 384 {
 385         struct clk *ck;
 386         unsigned long flags;
 387
 388         list_for_each_entry(ck, &clocks, node) {
 389                 if (ck->usecount > 0 || (ck->flags & ALWAYS_ENABLED) ||
 390                         ck->enable_reg == 0)
 391                         continue;
 392
 393                 spin_lock_irqsave(&clockfw_lock, flags);
 394                 if (arch_clock->clk_disable_unused)
 395                         arch_clock->clk_disable_unused(ck);
 396                 spin_unlock_irqrestore(&clockfw_lock, flags);
 397         }
 398
 399         return 0;
 400 }
 401 late_initcall(clk_disable_unused);
 402 #endif
 403
 404 int __init clk_init(struct clk_functions * custom_clocks)
 405 {
 406         if (!custom_clocks) {
 407                 printk(KERN_ERR "No custom clock functions registered\n");
 408                 BUG();
 409         }
 410
 411         arch_clock = custom_clocks;
 412
 413         return 0;
 414 }
 415
 416 #if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
 417 /*
 418  *      debugfs support to trace clock tree hierarchy and attributes
 419  */
 420 static struct dentry *clk_debugfs_root;
 421
 422 static int clk_debugfs_register_one(struct clk *c)
 423 {
 424         int err;
 425         struct dentry *d, *child;
 426         struct clk *pa = c->parent;
 427         char s[255];
 428         char *p = s;
 429
 430         p += sprintf(p, "%s", c->name);
 431         if (c->id != 0)
 432                 sprintf(p, ":%d", c->id);
 433         d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
 434         if (IS_ERR(d))
 435                 return PTR_ERR(d);
 436         c->dent = d;
 437
 438         d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
 439         if (IS_ERR(d)) {
 440                 err = PTR_ERR(d);
 441                 goto err_out;
 442         }
 443         d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
 444         if (IS_ERR(d)) {
 445                 err = PTR_ERR(d);
 446                 goto err_out;
 447         }
 448         d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
 449         if (IS_ERR(d)) {
 450                 err = PTR_ERR(d);
 451                 goto err_out;
 452         }
 453         return 0;
 454
 455 err_out:
 456         d = c->dent;
 457         list_for_each_entry(child, &d->d_subdirs, d_u.d_child)
 458                 debugfs_remove(child);
 459         debugfs_remove(c->dent);
 460         return err;
 461 }
 462
 463 static int clk_debugfs_register(struct clk *c)
 464 {
 465         int err;
 466         struct clk *pa = c->parent;
 467
 468         if (pa && !pa->dent) {
 469                 err = clk_debugfs_register(pa);
 470                 if (err)
 471                         return err;
 472         }
 473
 474         if (!c->dent) {
 475                 err = clk_debugfs_register_one(c);
 476                 if (err)
 477                         return err;
 478         }
 479         return 0;
 480 }
 481
 482 static int __init clk_debugfs_init(void)
 483 {
 484         struct clk *c;
 485         struct dentry *d;
 486         int err;
 487
 488         d = debugfs_create_dir("clock", NULL);
 489         if (IS_ERR(d))
 490                 return PTR_ERR(d);
 491         clk_debugfs_root = d;
 492
 493         list_for_each_entry(c, &clocks, node) {
 494                 err = clk_debugfs_register(c);
 495                 if (err)
 496                         goto err_out;
 497         }
 498         return 0;
 499 err_out:
 500         debugfs_remove(clk_debugfs_root); /* REVISIT: Cleanup correctly */
 501         return err;
 502 }
 503 late_initcall(clk_debugfs_init);
 504
 505 #endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */