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         spin_unlock_irqrestore(&clockfw_lock, flags);
  89
  90         return ret;
  91 }
  92 EXPORT_SYMBOL(clk_enable);
  93
  94 void clk_disable(struct clk *clk)
  95 {
  96         unsigned long flags;
  97
  98         if (clk == NULL || IS_ERR(clk))
  99                 return;
 100
 101         spin_lock_irqsave(&clockfw_lock, flags);
 102         if (clk->usecount == 0) {
 103                 printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
 104                        clk->name);
 105                 WARN_ON(1);
 106                 goto out;
 107         }
 108
 109         if (arch_clock->clk_disable)
 110                 arch_clock->clk_disable(clk);
 111
 112 out:
 113         spin_unlock_irqrestore(&clockfw_lock, flags);
 114 }
 115 EXPORT_SYMBOL(clk_disable);
 116
 117 int clk_get_usecount(struct clk *clk)
 118 {
 119         unsigned long flags;
 120         int ret = 0;
 121
 122         if (clk == NULL || IS_ERR(clk))
 123                 return 0;
 124
 125         spin_lock_irqsave(&clockfw_lock, flags);
 126         ret = clk->usecount;
 127         spin_unlock_irqrestore(&clockfw_lock, flags);
 128
 129         return ret;
 130 }
 131 EXPORT_SYMBOL(clk_get_usecount);
 132
 133 unsigned long clk_get_rate(struct clk *clk)
 134 {
 135         unsigned long flags;
 136         unsigned long ret = 0;
 137
 138         if (clk == NULL || IS_ERR(clk))
 139                 return 0;
 140
 141         spin_lock_irqsave(&clockfw_lock, flags);
 142         ret = clk->rate;
 143         spin_unlock_irqrestore(&clockfw_lock, flags);
 144
 145         return ret;
 146 }
 147 EXPORT_SYMBOL(clk_get_rate);
 148
 149 void clk_put(struct clk *clk)
 150 {
 151         if (clk && !IS_ERR(clk))
 152                 module_put(clk->owner);
 153 }
 154 EXPORT_SYMBOL(clk_put);
 155
 156 /*-------------------------------------------------------------------------
 157  * Optional clock functions defined in include/linux/clk.h
 158  *-------------------------------------------------------------------------*/
 159
 160 long clk_round_rate(struct clk *clk, unsigned long rate)
 161 {
 162         unsigned long flags;
 163         long ret = 0;
 164
 165         if (clk == NULL || IS_ERR(clk))
 166                 return ret;
 167
 168         spin_lock_irqsave(&clockfw_lock, flags);
 169         if (arch_clock->clk_round_rate)
 170                 ret = arch_clock->clk_round_rate(clk, rate);
 171         spin_unlock_irqrestore(&clockfw_lock, flags);
 172
 173         return ret;
 174 }
 175 EXPORT_SYMBOL(clk_round_rate);
 176
 177 int clk_set_rate(struct clk *clk, unsigned long rate)
 178 {
 179         unsigned long flags;
 180         int ret = -EINVAL;
 181
 182         if (clk == NULL || IS_ERR(clk))
 183                 return ret;
 184
 185         spin_lock_irqsave(&clockfw_lock, flags);
 186
 187         if (arch_clock->clk_set_rate) {
 188                 ret = arch_clock->clk_set_rate(clk, rate);
 189                 if (ret == 0) {
 190                         if (clk->recalc)
 191                                 (*clk->recalc)(clk);
 192                         if (clk->flags & RATE_PROPAGATES)
 193                                 propagate_rate(clk);
 194                 }
 195         }
 196
 197         spin_unlock_irqrestore(&clockfw_lock, flags);
 198
 199         return ret;
 200 }
 201 EXPORT_SYMBOL(clk_set_rate);
 202
 203 int clk_set_parent(struct clk *clk, struct clk *parent)
 204 {
 205         unsigned long flags;
 206         int ret = -EINVAL;
 207
 208         if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
 209                 return ret;
 210
 211         spin_lock_irqsave(&clockfw_lock, flags);
 212
 213         if (arch_clock->clk_set_parent) {
 214                 ret = arch_clock->clk_set_parent(clk, parent);
 215                 if (ret == 0) {
 216                         if (clk->recalc)
 217                                 (*clk->recalc)(clk);
 218                         if (clk->flags & RATE_PROPAGATES)
 219                                 propagate_rate(clk);
 220                 }
 221         }
 222
 223         spin_unlock_irqrestore(&clockfw_lock, flags);
 224
 225         return ret;
 226 }
 227 EXPORT_SYMBOL(clk_set_parent);
 228
 229 struct clk *clk_get_parent(struct clk *clk)
 230 {
 231         unsigned long flags;
 232         struct clk * ret = NULL;
 233
 234         if (clk == NULL || IS_ERR(clk))
 235                 return ret;
 236
 237         spin_lock_irqsave(&clockfw_lock, flags);
 238         if (arch_clock->clk_get_parent)
 239                 ret = arch_clock->clk_get_parent(clk);
 240         spin_unlock_irqrestore(&clockfw_lock, flags);
 241
 242         return ret;
 243 }
 244 EXPORT_SYMBOL(clk_get_parent);
 245
 246 /*-------------------------------------------------------------------------
 247  * OMAP specific clock functions shared between omap1 and omap2
 248  *-------------------------------------------------------------------------*/
 249
 250 unsigned int __initdata mpurate;
 251
 252 /*
 253  * By default we use the rate set by the bootloader.
 254  * You can override this with mpurate= cmdline option.
 255  */
 256 static int __init omap_clk_setup(char *str)
 257 {
 258         get_option(&str, &mpurate);
 259
 260         if (!mpurate)
 261                 return 1;
 262
 263         if (mpurate < 1000)
 264                 mpurate *= 1000000;
 265
 266         return 1;
 267 }
 268 __setup("mpurate=", omap_clk_setup);
 269
 270 /* Used for clocks that always have same value as the parent clock */
 271 void followparent_recalc(struct clk *clk)
 272 {
 273         if (clk == NULL || IS_ERR(clk))
 274                 return;
 275
 276         clk->rate = clk->parent->rate;
 277 }
 278
 279 /* Propagate rate to children */
 280 void propagate_rate(struct clk * tclk)
 281 {
 282         struct clk *clkp;
 283
 284         if (tclk == NULL || IS_ERR(tclk))
 285                 return;
 286
 287         list_for_each_entry(clkp, &clocks, node) {
 288                 if (likely(clkp->parent != tclk))
 289                         continue;
 290                 if (clkp->recalc)
 291                         clkp->recalc(clkp);
 292                 if (clkp->flags & RATE_PROPAGATES)
 293                         propagate_rate(clkp);
 294         }
 295 }
 296
 297 /**
 298  * recalculate_root_clocks - recalculate and propagate all root clocks
 299  *
 300  * Recalculates all root clocks (clocks with no parent), which if the
 301  * clock's .recalc is set correctly, should also propagate their rates.
 302  * Called at init.
 303  */
 304 void recalculate_root_clocks(void)
 305 {
 306         struct clk *clkp;
 307
 308         list_for_each_entry(clkp, &clocks, node) {
 309                 if (unlikely(!clkp->parent)) {
 310                         if (clkp->recalc)
 311                                 clkp->recalc(clkp);
 312                         if (clkp->flags & RATE_PROPAGATES)
 313                                 propagate_rate(clkp);
 314                 }
 315         }
 316 }
 317
 318 int clk_register(struct clk *clk)
 319 {
 320         if (clk == NULL || IS_ERR(clk))
 321                 return -EINVAL;
 322
 323         mutex_lock(&clocks_mutex);
 324         list_add(&clk->node, &clocks);
 325         if (clk->init)
 326                 clk->init(clk);
 327         mutex_unlock(&clocks_mutex);
 328
 329         return 0;
 330 }
 331 EXPORT_SYMBOL(clk_register);
 332
 333 void clk_unregister(struct clk *clk)
 334 {
 335         if (clk == NULL || IS_ERR(clk))
 336                 return;
 337
 338         mutex_lock(&clocks_mutex);
 339         list_del(&clk->node);
 340         mutex_unlock(&clocks_mutex);
 341 }
 342 EXPORT_SYMBOL(clk_unregister);
 343
 344 void clk_deny_idle(struct clk *clk)
 345 {
 346         unsigned long flags;
 347
 348         if (clk == NULL || IS_ERR(clk))
 349                 return;
 350
 351         spin_lock_irqsave(&clockfw_lock, flags);
 352         if (arch_clock->clk_deny_idle)
 353                 arch_clock->clk_deny_idle(clk);
 354         spin_unlock_irqrestore(&clockfw_lock, flags);
 355 }
 356 EXPORT_SYMBOL(clk_deny_idle);
 357
 358 void clk_allow_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_allow_idle)
 367                 arch_clock->clk_allow_idle(clk);
 368         spin_unlock_irqrestore(&clockfw_lock, flags);
 369 }
 370 EXPORT_SYMBOL(clk_allow_idle);
 371
 372 void clk_enable_init_clocks(void)
 373 {
 374         struct clk *clkp;
 375
 376         list_for_each_entry(clkp, &clocks, node) {
 377                 if (clkp->flags & ENABLE_ON_INIT)
 378                         clk_enable(clkp);
 379         }
 380 }
 381 EXPORT_SYMBOL(clk_enable_init_clocks);
 382
 383 #ifdef CONFIG_CPU_FREQ
 384 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
 385 {
 386         unsigned long flags;
 387
 388         spin_lock_irqsave(&clockfw_lock, flags);
 389         if (arch_clock->clk_init_cpufreq_table)
 390                 arch_clock->clk_init_cpufreq_table(table);
 391         spin_unlock_irqrestore(&clockfw_lock, flags);
 392 }
 393 EXPORT_SYMBOL(clk_init_cpufreq_table);
 394 #endif
 395
 396 /*-------------------------------------------------------------------------*/
 397
 398 #ifdef CONFIG_OMAP_RESET_CLOCKS
 399 /*
 400  * Disable any unused clocks left on by the bootloader
 401  */
 402 static int __init clk_disable_unused(void)
 403 {
 404         struct clk *ck;
 405         unsigned long flags;
 406
 407         list_for_each_entry(ck, &clocks, node) {
 408                 if (ck->usecount > 0 ||
 409                     (ck->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK)))
 410                         continue;
 411
 412                 if (cpu_class_is_omap1() && ck->enable_reg == 0)
 413                         continue;
 414
 415                 spin_lock_irqsave(&clockfw_lock, flags);
 416                 if (arch_clock->clk_disable_unused)
 417                         arch_clock->clk_disable_unused(ck);
 418                 spin_unlock_irqrestore(&clockfw_lock, flags);
 419         }
 420
 421         return 0;
 422 }
 423 late_initcall(clk_disable_unused);
 424 #endif
 425
 426 int __init clk_init(struct clk_functions * custom_clocks)
 427 {
 428         if (!custom_clocks) {
 429                 printk(KERN_ERR "No custom clock functions registered\n");
 430                 BUG();
 431         }
 432
 433         arch_clock = custom_clocks;
 434
 435         return 0;
 436 }
 437
 438 #if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
 439 /*
 440  *      debugfs support to trace clock tree hierarchy and attributes
 441  */
 442 static struct dentry *clk_debugfs_root;
 443
 444 static int clk_debugfs_register_one(struct clk *c)
 445 {
 446         int err;
 447         struct dentry *d, *child;
 448         struct clk *pa = c->parent;
 449         char s[255];
 450         char *p = s;
 451
 452         p += sprintf(p, "%s", c->name);
 453         if (c->id != 0)
 454                 sprintf(p, ":%d", c->id);
 455         d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
 456         if (!d)
 457                 return -ENOMEM;
 458         c->dent = d;
 459
 460         d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
 461         if (!d) {
 462                 err = -ENOMEM;
 463                 goto err_out;
 464         }
 465         d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
 466         if (!d) {
 467                 err = -ENOMEM;
 468                 goto err_out;
 469         }
 470         d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
 471         if (!d) {
 472                 err = -ENOMEM;
 473                 goto err_out;
 474         }
 475         return 0;
 476
 477 err_out:
 478         d = c->dent;
 479         list_for_each_entry(child, &d->d_subdirs, d_u.d_child)
 480                 debugfs_remove(child);
 481         debugfs_remove(c->dent);
 482         return err;
 483 }
 484
 485 static int clk_debugfs_register(struct clk *c)
 486 {
 487         int err;
 488         struct clk *pa = c->parent;
 489
 490         if (pa && !pa->dent) {
 491                 err = clk_debugfs_register(pa);
 492                 if (err)
 493                         return err;
 494         }
 495
 496         if (!c->dent) {
 497                 err = clk_debugfs_register_one(c);
 498                 if (err)
 499                         return err;
 500         }
 501         return 0;
 502 }
 503
 504 static int __init clk_debugfs_init(void)
 505 {
 506         struct clk *c;
 507         struct dentry *d;
 508         int err;
 509
 510         d = debugfs_create_dir("clock", NULL);
 511         if (!d)
 512                 return -ENOMEM;
 513         clk_debugfs_root = d;
 514
 515         list_for_each_entry(c, &clocks, node) {
 516                 err = clk_debugfs_register(c);
 517                 if (err)
 518                         goto err_out;
 519         }
 520         return 0;
 521 err_out:
 522         debugfs_remove(clk_debugfs_root); /* REVISIT: Cleanup correctly */
 523         return err;
 524 }
 525 late_initcall(clk_debugfs_init);
 526
 527 #endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */