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/config.h>
  15 #include <linux/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/list.h>
  19 #include <linux/errno.h>
  20 #include <linux/err.h>
  21 #include <linux/string.h>
  22 #include <linux/clk.h>
  23 #include <linux/mutex.h>
  24 #include <linux/platform_device.h>
  25
  26 #include <asm/io.h>
  27 #include <asm/semaphore.h>
  28
  29 #include <asm/arch/clock.h>
  30
  31 LIST_HEAD(clocks);
  32 static DEFINE_MUTEX(clocks_mutex);
  33 DEFINE_SPINLOCK(clockfw_lock);
  34
  35 static struct clk_functions *arch_clock;
  36
  37 /*-------------------------------------------------------------------------
  38  * Standard clock functions defined in include/linux/clk.h
  39  *-------------------------------------------------------------------------*/
  40
  41 /*
  42  * Returns a clock. Note that we first try to use device id on the bus
  43  * and clock name. If this fails, we try to use clock name only.
  44  */
  45 struct clk * clk_get(struct device *dev, const char *id)
  46 {
  47         struct clk *p, *clk = ERR_PTR(-ENOENT);
  48         int idno;
  49
  50         if (dev == NULL || dev->bus != &platform_bus_type)
  51                 idno = -1;
  52         else
  53                 idno = to_platform_device(dev)->id;
  54
  55         mutex_lock(&clocks_mutex);
  56
  57         list_for_each_entry(p, &clocks, node) {
  58                 if (p->id == idno &&
  59                     strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  60                         clk = p;
  61                         break;
  62                 }
  63         }
  64
  65         list_for_each_entry(p, &clocks, node) {
  66                 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  67                         clk = p;
  68                         break;
  69                 }
  70         }
  71
  72         mutex_unlock(&clocks_mutex);
  73
  74         return clk;
  75 }
  76 EXPORT_SYMBOL(clk_get);
  77
  78 int clk_enable(struct clk *clk)
  79 {
  80         unsigned long flags;
  81         int ret = 0;
  82
  83         if (clk == NULL || IS_ERR(clk))
  84                 return -ENODEV;
  85
  86         spin_lock_irqsave(&clockfw_lock, flags);
  87         if (arch_clock->clk_enable)
  88                 ret = arch_clock->clk_enable(clk);
  89         spin_unlock_irqrestore(&clockfw_lock, flags);
  90
  91         return ret;
  92 }
  93 EXPORT_SYMBOL(clk_enable);
  94
  95 void clk_disable(struct clk *clk)
  96 {
  97         unsigned long flags;
  98
  99         if (clk == NULL || IS_ERR(clk))
 100                 return;
 101
 102         spin_lock_irqsave(&clockfw_lock, flags);
 103         if (arch_clock->clk_disable)
 104                 arch_clock->clk_disable(clk);
 105         spin_unlock_irqrestore(&clockfw_lock, flags);
 106 }
 107 EXPORT_SYMBOL(clk_disable);
 108
 109 int clk_get_usecount(struct clk *clk)
 110 {
 111         unsigned long flags;
 112         int ret = 0;
 113
 114         if (clk == NULL || IS_ERR(clk))
 115                 return 0;
 116
 117         spin_lock_irqsave(&clockfw_lock, flags);
 118         ret = clk->usecount;
 119         spin_unlock_irqrestore(&clockfw_lock, flags);
 120
 121         return ret;
 122 }
 123 EXPORT_SYMBOL(clk_get_usecount);
 124
 125 unsigned long clk_get_rate(struct clk *clk)
 126 {
 127         unsigned long flags;
 128         unsigned long ret = 0;
 129
 130         if (clk == NULL || IS_ERR(clk))
 131                 return 0;
 132
 133         spin_lock_irqsave(&clockfw_lock, flags);
 134         ret = clk->rate;
 135         spin_unlock_irqrestore(&clockfw_lock, flags);
 136
 137         return ret;
 138 }
 139 EXPORT_SYMBOL(clk_get_rate);
 140
 141 void clk_put(struct clk *clk)
 142 {
 143         if (clk && !IS_ERR(clk))
 144                 module_put(clk->owner);
 145 }
 146 EXPORT_SYMBOL(clk_put);
 147
 148 /*-------------------------------------------------------------------------
 149  * Optional clock functions defined in include/linux/clk.h
 150  *-------------------------------------------------------------------------*/
 151
 152 long clk_round_rate(struct clk *clk, unsigned long rate)
 153 {
 154         unsigned long flags;
 155         long ret = 0;
 156
 157         spin_lock_irqsave(&clockfw_lock, flags);
 158         if (arch_clock->clk_round_rate)
 159                 ret = arch_clock->clk_round_rate(clk, rate);
 160         spin_unlock_irqrestore(&clockfw_lock, flags);
 161
 162         return ret;
 163 }
 164 EXPORT_SYMBOL(clk_round_rate);
 165
 166 int clk_set_rate(struct clk *clk, unsigned long rate)
 167 {
 168         unsigned long flags;
 169         int ret = 0;
 170
 171         spin_lock_irqsave(&clockfw_lock, flags);
 172         if (arch_clock->clk_set_rate)
 173                 ret = arch_clock->clk_set_rate(clk, rate);
 174         spin_unlock_irqrestore(&clockfw_lock, flags);
 175
 176         return ret;
 177 }
 178 EXPORT_SYMBOL(clk_set_rate);
 179
 180 int clk_set_parent(struct clk *clk, struct clk *parent)
 181 {
 182         unsigned long flags;
 183         int ret = 0;
 184
 185         spin_lock_irqsave(&clockfw_lock, flags);
 186         if (arch_clock->clk_set_parent)
 187                 ret =  arch_clock->clk_set_parent(clk, parent);
 188         spin_unlock_irqrestore(&clockfw_lock, flags);
 189
 190         return ret;
 191 }
 192 EXPORT_SYMBOL(clk_set_parent);
 193
 194 struct clk *clk_get_parent(struct clk *clk)
 195 {
 196         unsigned long flags;
 197         struct clk * ret = NULL;
 198
 199         spin_lock_irqsave(&clockfw_lock, flags);
 200         if (arch_clock->clk_get_parent)
 201                 ret = arch_clock->clk_get_parent(clk);
 202         spin_unlock_irqrestore(&clockfw_lock, flags);
 203
 204         return ret;
 205 }
 206 EXPORT_SYMBOL(clk_get_parent);
 207
 208 /*-------------------------------------------------------------------------
 209  * OMAP specific clock functions shared between omap1 and omap2
 210  *-------------------------------------------------------------------------*/
 211
 212 unsigned int __initdata mpurate;
 213
 214 /*
 215  * By default we use the rate set by the bootloader.
 216  * You can override this with mpurate= cmdline option.
 217  */
 218 static int __init omap_clk_setup(char *str)
 219 {
 220         get_option(&str, &mpurate);
 221
 222         if (!mpurate)
 223                 return 1;
 224
 225         if (mpurate < 1000)
 226                 mpurate *= 1000000;
 227
 228         return 1;
 229 }
 230 __setup("mpurate=", omap_clk_setup);
 231
 232 /* Used for clocks that always have same value as the parent clock */
 233 void followparent_recalc(struct clk *clk)
 234 {
 235         clk->rate = clk->parent->rate;
 236 }
 237
 238 /* Propagate rate to children */
 239 void propagate_rate(struct clk * tclk)
 240 {
 241         struct clk *clkp;
 242
 243         list_for_each_entry(clkp, &clocks, node) {
 244                 if (likely(clkp->parent != tclk))
 245                         continue;
 246                 if (likely((u32)clkp->recalc))
 247                         clkp->recalc(clkp);
 248         }
 249 }
 250
 251 int clk_register(struct clk *clk)
 252 {
 253         mutex_lock(&clocks_mutex);
 254         list_add(&clk->node, &clocks);
 255         if (clk->init)
 256                 clk->init(clk);
 257         mutex_unlock(&clocks_mutex);
 258
 259         return 0;
 260 }
 261 EXPORT_SYMBOL(clk_register);
 262
 263 void clk_unregister(struct clk *clk)
 264 {
 265         mutex_lock(&clocks_mutex);
 266         list_del(&clk->node);
 267         mutex_unlock(&clocks_mutex);
 268 }
 269 EXPORT_SYMBOL(clk_unregister);
 270
 271 void clk_deny_idle(struct clk *clk)
 272 {
 273         unsigned long flags;
 274
 275         spin_lock_irqsave(&clockfw_lock, flags);
 276         if (arch_clock->clk_deny_idle)
 277                 arch_clock->clk_deny_idle(clk);
 278         spin_unlock_irqrestore(&clockfw_lock, flags);
 279 }
 280 EXPORT_SYMBOL(clk_deny_idle);
 281
 282 void clk_allow_idle(struct clk *clk)
 283 {
 284         unsigned long flags;
 285
 286         spin_lock_irqsave(&clockfw_lock, flags);
 287         if (arch_clock->clk_allow_idle)
 288                 arch_clock->clk_allow_idle(clk);
 289         spin_unlock_irqrestore(&clockfw_lock, flags);
 290 }
 291 EXPORT_SYMBOL(clk_allow_idle);
 292
 293 /*-------------------------------------------------------------------------*/
 294
 295 int __init clk_init(struct clk_functions * custom_clocks)
 296 {
 297         if (!custom_clocks) {
 298                 printk(KERN_ERR "No custom clock functions registered\n");
 299                 BUG();
 300         }
 301
 302         arch_clock = custom_clocks;
 303
 304         return 0;
 305 }
 306
 307 #ifdef CONFIG_PROC_FS
 308 #include <linux/proc_fs.h>
 309 #include <linux/seq_file.h>
 310
 311 static void *omap_ck_start(struct seq_file *m, loff_t *pos)
 312 {
 313         return *pos < 1 ? (void *)1 : NULL;
 314 }
 315
 316 static void *omap_ck_next(struct seq_file *m, void *v, loff_t *pos)
 317 {
 318         ++*pos;
 319         return NULL;
 320 }
 321
 322 static void omap_ck_stop(struct seq_file *m, void *v)
 323 {
 324 }
 325
 326 int omap_ck_show(struct seq_file *m, void *v)
 327 {
 328         struct clk *cp;
 329
 330         list_for_each_entry(cp, &clocks, node)
 331                 seq_printf(m,"%s %ld %d\n", cp->name, cp->rate, cp->usecount);
 332
 333         return 0;
 334 }
 335
 336 static struct seq_operations omap_ck_op = {
 337         .start =        omap_ck_start,
 338         .next =         omap_ck_next,
 339         .stop =         omap_ck_stop,
 340         .show =         omap_ck_show
 341 };
 342
 343 static int omap_ck_open(struct inode *inode, struct file *file)
 344 {
 345         return seq_open(file, &omap_ck_op);
 346 }
 347
 348 static struct file_operations proc_omap_ck_operations = {
 349         .open           = omap_ck_open,
 350         .read           = seq_read,
 351         .llseek         = seq_lseek,
 352         .release        = seq_release,
 353 };
 354
 355 int __init omap_ck_init(void)
 356 {
 357     struct proc_dir_entry *entry;
 358
 359         entry = create_proc_entry("omap_clocks", 0, NULL);
 360         if (entry)
 361                 entry->proc_fops = &proc_omap_ck_operations;
 362         return 0;
 363
 364 }
 365 __initcall(omap_ck_init);
 366 #endif /* CONFIG_DEBUG_PROC_FS */
 367