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         if (arch_clock->clk_set_rate)
 187                 ret = arch_clock->clk_set_rate(clk, rate);
 188         spin_unlock_irqrestore(&clockfw_lock, flags);
 189
 190         return ret;
 191 }
 192 EXPORT_SYMBOL(clk_set_rate);
 193
 194 int clk_set_parent(struct clk *clk, struct clk *parent)
 195 {
 196         unsigned long flags;
 197         int ret = -EINVAL;
 198
 199         if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
 200                 return ret;
 201
 202         spin_lock_irqsave(&clockfw_lock, flags);
 203         if (arch_clock->clk_set_parent)
 204                 ret =  arch_clock->clk_set_parent(clk, parent);
 205         spin_unlock_irqrestore(&clockfw_lock, flags);
 206
 207         return ret;
 208 }
 209 EXPORT_SYMBOL(clk_set_parent);
 210
 211 struct clk *clk_get_parent(struct clk *clk)
 212 {
 213         unsigned long flags;
 214         struct clk * ret = NULL;
 215
 216         if (clk == NULL || IS_ERR(clk))
 217                 return ret;
 218
 219         spin_lock_irqsave(&clockfw_lock, flags);
 220         if (arch_clock->clk_get_parent)
 221                 ret = arch_clock->clk_get_parent(clk);
 222         spin_unlock_irqrestore(&clockfw_lock, flags);
 223
 224         return ret;
 225 }
 226 EXPORT_SYMBOL(clk_get_parent);
 227
 228 /*-------------------------------------------------------------------------
 229  * OMAP specific clock functions shared between omap1 and omap2
 230  *-------------------------------------------------------------------------*/
 231
 232 unsigned int __initdata mpurate;
 233
 234 /*
 235  * By default we use the rate set by the bootloader.
 236  * You can override this with mpurate= cmdline option.
 237  */
 238 static int __init omap_clk_setup(char *str)
 239 {
 240         get_option(&str, &mpurate);
 241
 242         if (!mpurate)
 243                 return 1;
 244
 245         if (mpurate < 1000)
 246                 mpurate *= 1000000;
 247
 248         return 1;
 249 }
 250 __setup("mpurate=", omap_clk_setup);
 251
 252 /* Used for clocks that always have same value as the parent clock */
 253 void followparent_recalc(struct clk *clk)
 254 {
 255         if (clk == NULL || IS_ERR(clk))
 256                 return;
 257
 258         clk->rate = clk->parent->rate;
 259         if (unlikely(clk->flags & RATE_PROPAGATES))
 260                 propagate_rate(clk);
 261 }
 262
 263 /* Propagate rate to children */
 264 void propagate_rate(struct clk * tclk)
 265 {
 266         struct clk *clkp;
 267
 268         if (tclk == NULL || IS_ERR(tclk))
 269                 return;
 270
 271         list_for_each_entry(clkp, &clocks, node) {
 272                 if (likely(clkp->parent != tclk))
 273                         continue;
 274                 if (likely((u32)clkp->recalc))
 275                         clkp->recalc(clkp);
 276         }
 277 }
 278
 279 /**
 280  * recalculate_root_clocks - recalculate and propagate all root clocks
 281  *
 282  * Recalculates all root clocks (clocks with no parent), which if the
 283  * clock's .recalc is set correctly, should also propagate their rates.
 284  * Called at init.
 285  */
 286 void recalculate_root_clocks(void)
 287 {
 288         struct clk *clkp;
 289
 290         list_for_each_entry(clkp, &clocks, node) {
 291                 if (unlikely(!clkp->parent) && likely((u32)clkp->recalc))
 292                         clkp->recalc(clkp);
 293         }
 294 }
 295
 296 int clk_register(struct clk *clk)
 297 {
 298         if (clk == NULL || IS_ERR(clk))
 299                 return -EINVAL;
 300
 301         mutex_lock(&clocks_mutex);
 302         list_add(&clk->node, &clocks);
 303         if (clk->init)
 304                 clk->init(clk);
 305         mutex_unlock(&clocks_mutex);
 306
 307         return 0;
 308 }
 309 EXPORT_SYMBOL(clk_register);
 310
 311 void clk_unregister(struct clk *clk)
 312 {
 313         if (clk == NULL || IS_ERR(clk))
 314                 return;
 315
 316         mutex_lock(&clocks_mutex);
 317         list_del(&clk->node);
 318         mutex_unlock(&clocks_mutex);
 319 }
 320 EXPORT_SYMBOL(clk_unregister);
 321
 322 void clk_deny_idle(struct clk *clk)
 323 {
 324         unsigned long flags;
 325
 326         if (clk == NULL || IS_ERR(clk))
 327                 return;
 328
 329         spin_lock_irqsave(&clockfw_lock, flags);
 330         if (arch_clock->clk_deny_idle)
 331                 arch_clock->clk_deny_idle(clk);
 332         spin_unlock_irqrestore(&clockfw_lock, flags);
 333 }
 334 EXPORT_SYMBOL(clk_deny_idle);
 335
 336 void clk_allow_idle(struct clk *clk)
 337 {
 338         unsigned long flags;
 339
 340         if (clk == NULL || IS_ERR(clk))
 341                 return;
 342
 343         spin_lock_irqsave(&clockfw_lock, flags);
 344         if (arch_clock->clk_allow_idle)
 345                 arch_clock->clk_allow_idle(clk);
 346         spin_unlock_irqrestore(&clockfw_lock, flags);
 347 }
 348 EXPORT_SYMBOL(clk_allow_idle);
 349
 350 void clk_enable_init_clocks(void)
 351 {
 352         struct clk *clkp;
 353
 354         list_for_each_entry(clkp, &clocks, node) {
 355                 if (clkp->flags & ENABLE_ON_INIT)
 356                         clk_enable(clkp);
 357         }
 358 }
 359 EXPORT_SYMBOL(clk_enable_init_clocks);
 360
 361 #ifdef CONFIG_CPU_FREQ
 362 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
 363 {
 364         unsigned long flags;
 365
 366         spin_lock_irqsave(&clockfw_lock, flags);
 367         if (arch_clock->clk_init_cpufreq_table)
 368                 arch_clock->clk_init_cpufreq_table(table);
 369         spin_unlock_irqrestore(&clockfw_lock, flags);
 370 }
 371 EXPORT_SYMBOL(clk_init_cpufreq_table);
 372 #endif
 373
 374 /*-------------------------------------------------------------------------*/
 375
 376 #ifdef CONFIG_OMAP_RESET_CLOCKS
 377 /*
 378  * Disable any unused clocks left on by the bootloader
 379  */
 380 static int __init clk_disable_unused(void)
 381 {
 382         struct clk *ck;
 383         unsigned long flags;
 384
 385         list_for_each_entry(ck, &clocks, node) {
 386                 if (ck->usecount > 0 ||
 387                     (ck->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK)))
 388                         continue;
 389
 390                 if (cpu_class_is_omap1() && 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 (!d)
 435                 return -ENOMEM;
 436         c->dent = d;
 437
 438         d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
 439         if (!d) {
 440                 err = -ENOMEM;
 441                 goto err_out;
 442         }
 443         d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
 444         if (!d) {
 445                 err = -ENOMEM;
 446                 goto err_out;
 447         }
 448         d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
 449         if (!d) {
 450                 err = -ENOMEM;
 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 (!d)
 490                 return -ENOMEM;
 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) */