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
  25 #include <asm/io.h>
  26 #include <asm/semaphore.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         BUG_ON(clk->usecount == 0);
 139         if (arch_clock->clk_disable)
 140                 arch_clock->clk_disable(clk);
 141         spin_unlock_irqrestore(&clockfw_lock, flags);
 142 }
 143 EXPORT_SYMBOL(clk_disable);
 144
 145 int clk_get_usecount(struct clk *clk)
 146 {
 147         unsigned long flags;
 148         int ret = 0;
 149
 150         if (clk == NULL || IS_ERR(clk))
 151                 return 0;
 152
 153         spin_lock_irqsave(&clockfw_lock, flags);
 154         ret = clk->usecount;
 155         spin_unlock_irqrestore(&clockfw_lock, flags);
 156
 157         return ret;
 158 }
 159 EXPORT_SYMBOL(clk_get_usecount);
 160
 161 unsigned long clk_get_rate(struct clk *clk)
 162 {
 163         unsigned long flags;
 164         unsigned long ret = 0;
 165
 166         if (clk == NULL || IS_ERR(clk))
 167                 return 0;
 168
 169         spin_lock_irqsave(&clockfw_lock, flags);
 170         ret = clk->rate;
 171         spin_unlock_irqrestore(&clockfw_lock, flags);
 172
 173         return ret;
 174 }
 175 EXPORT_SYMBOL(clk_get_rate);
 176
 177 void clk_put(struct clk *clk)
 178 {
 179         if (clk && !IS_ERR(clk))
 180                 module_put(clk->owner);
 181 }
 182 EXPORT_SYMBOL(clk_put);
 183
 184 /*-------------------------------------------------------------------------
 185  * Optional clock functions defined in include/linux/clk.h
 186  *-------------------------------------------------------------------------*/
 187
 188 long clk_round_rate(struct clk *clk, unsigned long rate)
 189 {
 190         unsigned long flags;
 191         long ret = 0;
 192
 193         if (clk == NULL || IS_ERR(clk))
 194                 return ret;
 195
 196         spin_lock_irqsave(&clockfw_lock, flags);
 197         if (arch_clock->clk_round_rate)
 198                 ret = arch_clock->clk_round_rate(clk, rate);
 199         spin_unlock_irqrestore(&clockfw_lock, flags);
 200
 201         return ret;
 202 }
 203 EXPORT_SYMBOL(clk_round_rate);
 204
 205 int clk_set_rate(struct clk *clk, unsigned long rate)
 206 {
 207         unsigned long flags;
 208         int ret = -EINVAL;
 209
 210         if (clk == NULL || IS_ERR(clk))
 211                 return ret;
 212
 213         spin_lock_irqsave(&clockfw_lock, flags);
 214         if (arch_clock->clk_set_rate)
 215                 ret = arch_clock->clk_set_rate(clk, rate);
 216         spin_unlock_irqrestore(&clockfw_lock, flags);
 217
 218         return ret;
 219 }
 220 EXPORT_SYMBOL(clk_set_rate);
 221
 222 int clk_set_parent(struct clk *clk, struct clk *parent)
 223 {
 224         unsigned long flags;
 225         int ret = -EINVAL;
 226
 227         if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
 228                 return ret;
 229
 230         spin_lock_irqsave(&clockfw_lock, flags);
 231         if (arch_clock->clk_set_parent)
 232                 ret =  arch_clock->clk_set_parent(clk, parent);
 233         spin_unlock_irqrestore(&clockfw_lock, flags);
 234
 235         return ret;
 236 }
 237 EXPORT_SYMBOL(clk_set_parent);
 238
 239 struct clk *clk_get_parent(struct clk *clk)
 240 {
 241         unsigned long flags;
 242         struct clk * ret = NULL;
 243
 244         if (clk == NULL || IS_ERR(clk))
 245                 return ret;
 246
 247         spin_lock_irqsave(&clockfw_lock, flags);
 248         if (arch_clock->clk_get_parent)
 249                 ret = arch_clock->clk_get_parent(clk);
 250         spin_unlock_irqrestore(&clockfw_lock, flags);
 251
 252         return ret;
 253 }
 254 EXPORT_SYMBOL(clk_get_parent);
 255
 256 /*-------------------------------------------------------------------------
 257  * OMAP specific clock functions shared between omap1 and omap2
 258  *-------------------------------------------------------------------------*/
 259
 260 unsigned int __initdata mpurate;
 261
 262 /*
 263  * By default we use the rate set by the bootloader.
 264  * You can override this with mpurate= cmdline option.
 265  */
 266 static int __init omap_clk_setup(char *str)
 267 {
 268         get_option(&str, &mpurate);
 269
 270         if (!mpurate)
 271                 return 1;
 272
 273         if (mpurate < 1000)
 274                 mpurate *= 1000000;
 275
 276         return 1;
 277 }
 278 __setup("mpurate=", omap_clk_setup);
 279
 280 /* Used for clocks that always have same value as the parent clock */
 281 void followparent_recalc(struct clk *clk)
 282 {
 283         if (clk == NULL || IS_ERR(clk))
 284                 return;
 285
 286         clk->rate = clk->parent->rate;
 287 }
 288
 289 /* Propagate rate to children */
 290 void propagate_rate(struct clk * tclk)
 291 {
 292         struct clk *clkp;
 293
 294         if (tclk == NULL || IS_ERR(tclk))
 295                 return;
 296
 297         list_for_each_entry(clkp, &clocks, node) {
 298                 if (likely(clkp->parent != tclk))
 299                         continue;
 300                 if (likely((u32)clkp->recalc))
 301                         clkp->recalc(clkp);
 302         }
 303 }
 304
 305 int clk_register(struct clk *clk)
 306 {
 307         if (clk == NULL || IS_ERR(clk))
 308                 return -EINVAL;
 309
 310         mutex_lock(&clocks_mutex);
 311         list_add(&clk->node, &clocks);
 312         if (clk->init)
 313                 clk->init(clk);
 314         mutex_unlock(&clocks_mutex);
 315
 316         return 0;
 317 }
 318 EXPORT_SYMBOL(clk_register);
 319
 320 void clk_unregister(struct clk *clk)
 321 {
 322         if (clk == NULL || IS_ERR(clk))
 323                 return;
 324
 325         mutex_lock(&clocks_mutex);
 326         list_del(&clk->node);
 327         mutex_unlock(&clocks_mutex);
 328 }
 329 EXPORT_SYMBOL(clk_unregister);
 330
 331 void clk_deny_idle(struct clk *clk)
 332 {
 333         unsigned long flags;
 334
 335         if (clk == NULL || IS_ERR(clk))
 336                 return;
 337
 338         spin_lock_irqsave(&clockfw_lock, flags);
 339         if (arch_clock->clk_deny_idle)
 340                 arch_clock->clk_deny_idle(clk);
 341         spin_unlock_irqrestore(&clockfw_lock, flags);
 342 }
 343 EXPORT_SYMBOL(clk_deny_idle);
 344
 345 void clk_allow_idle(struct clk *clk)
 346 {
 347         unsigned long flags;
 348
 349         if (clk == NULL || IS_ERR(clk))
 350                 return;
 351
 352         spin_lock_irqsave(&clockfw_lock, flags);
 353         if (arch_clock->clk_allow_idle)
 354                 arch_clock->clk_allow_idle(clk);
 355         spin_unlock_irqrestore(&clockfw_lock, flags);
 356 }
 357 EXPORT_SYMBOL(clk_allow_idle);
 358
 359 /*-------------------------------------------------------------------------*/
 360
 361 #ifdef CONFIG_OMAP_RESET_CLOCKS
 362 /*
 363  * Disable any unused clocks left on by the bootloader
 364  */
 365 static int __init clk_disable_unused(void)
 366 {
 367         struct clk *ck;
 368         unsigned long flags;
 369
 370         list_for_each_entry(ck, &clocks, node) {
 371                 if (ck->usecount > 0 || (ck->flags & ALWAYS_ENABLED) ||
 372                         ck->enable_reg == 0)
 373                         continue;
 374
 375                 spin_lock_irqsave(&clockfw_lock, flags);
 376                 if (arch_clock->clk_disable_unused)
 377                         arch_clock->clk_disable_unused(ck);
 378                 spin_unlock_irqrestore(&clockfw_lock, flags);
 379         }
 380
 381         return 0;
 382 }
 383 late_initcall(clk_disable_unused);
 384 #endif
 385
 386 int __init clk_init(struct clk_functions * custom_clocks)
 387 {
 388         if (!custom_clocks) {
 389                 printk(KERN_ERR "No custom clock functions registered\n");
 390                 BUG();
 391         }
 392
 393         arch_clock = custom_clocks;
 394
 395         return 0;
 396 }