release/src-rt-6.x.4708/linux/linux-2.6.36/arch/arm/mach-msm/clock.c

   1 /* arch/arm/mach-msm/clock.c
   2  *
   3  * Copyright (C) 2007 Google, Inc.
   4  * Copyright (c) 2007-2010, Code Aurora Forum. All rights reserved.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/init.h>
  19 #include <linux/module.h>
  20 #include <linux/list.h>
  21 #include <linux/err.h>
  22 #include <linux/clk.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/debugfs.h>
  25 #include <linux/ctype.h>
  26 #include <linux/pm_qos_params.h>
  27 #include <mach/clk.h>
  28
  29 #include "clock.h"
  30 #include "proc_comm.h"
  31 #include "clock-7x30.h"
  32
  33 static DEFINE_MUTEX(clocks_mutex);
  34 static DEFINE_SPINLOCK(clocks_lock);
  35 static LIST_HEAD(clocks);
  36 struct clk *msm_clocks;
  37 unsigned msm_num_clocks;
  38
  39 /*
  40  * Bitmap of enabled clocks, excluding ACPU which is always
  41  * enabled
  42  */
  43 static DECLARE_BITMAP(clock_map_enabled, NR_CLKS);
  44 static DEFINE_SPINLOCK(clock_map_lock);
  45
  46 /*
  47  * Standard clock functions defined in include/linux/clk.h
  48  */
  49 struct clk *clk_get(struct device *dev, const char *id)
  50 {
  51         struct clk *clk;
  52
  53         mutex_lock(&clocks_mutex);
  54
  55         list_for_each_entry(clk, &clocks, list)
  56                 if (!strcmp(id, clk->name) && clk->dev == dev)
  57                         goto found_it;
  58
  59         list_for_each_entry(clk, &clocks, list)
  60                 if (!strcmp(id, clk->name) && clk->dev == NULL)
  61                         goto found_it;
  62
  63         clk = ERR_PTR(-ENOENT);
  64 found_it:
  65         mutex_unlock(&clocks_mutex);
  66         return clk;
  67 }
  68 EXPORT_SYMBOL(clk_get);
  69
  70 void clk_put(struct clk *clk)
  71 {
  72 }
  73 EXPORT_SYMBOL(clk_put);
  74
  75 int clk_enable(struct clk *clk)
  76 {
  77         unsigned long flags;
  78         spin_lock_irqsave(&clocks_lock, flags);
  79         clk->count++;
  80         if (clk->count == 1) {
  81                 clk->ops->enable(clk->id);
  82                 spin_lock(&clock_map_lock);
  83                 clock_map_enabled[BIT_WORD(clk->id)] |= BIT_MASK(clk->id);
  84                 spin_unlock(&clock_map_lock);
  85         }
  86         spin_unlock_irqrestore(&clocks_lock, flags);
  87         return 0;
  88 }
  89 EXPORT_SYMBOL(clk_enable);
  90
  91 void clk_disable(struct clk *clk)
  92 {
  93         unsigned long flags;
  94         spin_lock_irqsave(&clocks_lock, flags);
  95         BUG_ON(clk->count == 0);
  96         clk->count--;
  97         if (clk->count == 0) {
  98                 clk->ops->disable(clk->id);
  99                 spin_lock(&clock_map_lock);
 100                 clock_map_enabled[BIT_WORD(clk->id)] &= ~BIT_MASK(clk->id);
 101                 spin_unlock(&clock_map_lock);
 102         }
 103         spin_unlock_irqrestore(&clocks_lock, flags);
 104 }
 105 EXPORT_SYMBOL(clk_disable);
 106
 107 int clk_reset(struct clk *clk, enum clk_reset_action action)
 108 {
 109         if (!clk->ops->reset)
 110                 clk->ops->reset = &pc_clk_reset;
 111         return clk->ops->reset(clk->remote_id, action);
 112 }
 113 EXPORT_SYMBOL(clk_reset);
 114
 115 unsigned long clk_get_rate(struct clk *clk)
 116 {
 117         return clk->ops->get_rate(clk->id);
 118 }
 119 EXPORT_SYMBOL(clk_get_rate);
 120
 121 int clk_set_rate(struct clk *clk, unsigned long rate)
 122 {
 123         return clk->ops->set_rate(clk->id, rate);
 124 }
 125 EXPORT_SYMBOL(clk_set_rate);
 126
 127 long clk_round_rate(struct clk *clk, unsigned long rate)
 128 {
 129         return clk->ops->round_rate(clk->id, rate);
 130 }
 131 EXPORT_SYMBOL(clk_round_rate);
 132
 133 int clk_set_min_rate(struct clk *clk, unsigned long rate)
 134 {
 135         return clk->ops->set_min_rate(clk->id, rate);
 136 }
 137 EXPORT_SYMBOL(clk_set_min_rate);
 138
 139 int clk_set_max_rate(struct clk *clk, unsigned long rate)
 140 {
 141         return clk->ops->set_max_rate(clk->id, rate);
 142 }
 143 EXPORT_SYMBOL(clk_set_max_rate);
 144
 145 int clk_set_parent(struct clk *clk, struct clk *parent)
 146 {
 147         return -ENOSYS;
 148 }
 149 EXPORT_SYMBOL(clk_set_parent);
 150
 151 struct clk *clk_get_parent(struct clk *clk)
 152 {
 153         return ERR_PTR(-ENOSYS);
 154 }
 155 EXPORT_SYMBOL(clk_get_parent);
 156
 157 int clk_set_flags(struct clk *clk, unsigned long flags)
 158 {
 159         if (clk == NULL || IS_ERR(clk))
 160                 return -EINVAL;
 161         return clk->ops->set_flags(clk->id, flags);
 162 }
 163 EXPORT_SYMBOL(clk_set_flags);
 164
 165 /* EBI1 is the only shared clock that several clients want to vote on as of
 166  * this commit. If this changes in the future, then it might be better to
 167  * make clk_min_rate handle the voting or make ebi1_clk_set_min_rate more
 168  * generic to support different clocks.
 169  */
 170 static struct clk *ebi1_clk;
 171
 172 static void __init set_clock_ops(struct clk *clk)
 173 {
 174         if (!clk->ops) {
 175                 clk->ops = &clk_ops_pcom;
 176                 clk->id = clk->remote_id;
 177         }
 178 }
 179
 180 void __init msm_clock_init(struct clk *clock_tbl, unsigned num_clocks)
 181 {
 182         unsigned n;
 183
 184         spin_lock_init(&clocks_lock);
 185         mutex_lock(&clocks_mutex);
 186         msm_clocks = clock_tbl;
 187         msm_num_clocks = num_clocks;
 188         for (n = 0; n < msm_num_clocks; n++) {
 189                 set_clock_ops(&msm_clocks[n]);
 190                 list_add_tail(&msm_clocks[n].list, &clocks);
 191         }
 192         mutex_unlock(&clocks_mutex);
 193
 194         ebi1_clk = clk_get(NULL, "ebi1_clk");
 195         BUG_ON(ebi1_clk == NULL);
 196
 197 }
 198
 199 #if defined(CONFIG_DEBUG_FS)
 200 static struct clk *msm_clock_get_nth(unsigned index)
 201 {
 202         if (index < msm_num_clocks)
 203                 return msm_clocks + index;
 204         else
 205                 return 0;
 206 }
 207
 208 static int clock_debug_rate_set(void *data, u64 val)
 209 {
 210         struct clk *clock = data;
 211         int ret;
 212
 213         /* Only increases to max rate will succeed, but that's actually good
 214          * for debugging purposes. So we don't check for error. */
 215         if (clock->flags & CLK_MAX)
 216                 clk_set_max_rate(clock, val);
 217         if (clock->flags & CLK_MIN)
 218                 ret = clk_set_min_rate(clock, val);
 219         else
 220                 ret = clk_set_rate(clock, val);
 221         if (ret != 0)
 222                 printk(KERN_ERR "clk_set%s_rate failed (%d)\n",
 223                         (clock->flags & CLK_MIN) ? "_min" : "", ret);
 224         return ret;
 225 }
 226
 227 static int clock_debug_rate_get(void *data, u64 *val)
 228 {
 229         struct clk *clock = data;
 230         *val = clk_get_rate(clock);
 231         return 0;
 232 }
 233
 234 static int clock_debug_enable_set(void *data, u64 val)
 235 {
 236         struct clk *clock = data;
 237         int rc = 0;
 238
 239         if (val)
 240                 rc = clock->ops->enable(clock->id);
 241         else
 242                 clock->ops->disable(clock->id);
 243
 244         return rc;
 245 }
 246
 247 static int clock_debug_enable_get(void *data, u64 *val)
 248 {
 249         struct clk *clock = data;
 250
 251         *val = clock->ops->is_enabled(clock->id);
 252
 253         return 0;
 254 }
 255
 256 static int clock_debug_local_get(void *data, u64 *val)
 257 {
 258         struct clk *clock = data;
 259
 260         *val = clock->ops != &clk_ops_pcom;
 261
 262         return 0;
 263 }
 264
 265 DEFINE_SIMPLE_ATTRIBUTE(clock_rate_fops, clock_debug_rate_get,
 266                         clock_debug_rate_set, "%llu\n");
 267 DEFINE_SIMPLE_ATTRIBUTE(clock_enable_fops, clock_debug_enable_get,
 268                         clock_debug_enable_set, "%llu\n");
 269 DEFINE_SIMPLE_ATTRIBUTE(clock_local_fops, clock_debug_local_get,
 270                         NULL, "%llu\n");
 271
 272 static int __init clock_debug_init(void)
 273 {
 274         struct dentry *dent_rate, *dent_enable, *dent_local;
 275         struct clk *clock;
 276         unsigned n = 0;
 277         char temp[50], *ptr;
 278
 279         dent_rate = debugfs_create_dir("clk_rate", 0);
 280         if (IS_ERR(dent_rate))
 281                 return PTR_ERR(dent_rate);
 282
 283         dent_enable = debugfs_create_dir("clk_enable", 0);
 284         if (IS_ERR(dent_enable))
 285                 return PTR_ERR(dent_enable);
 286
 287         dent_local = debugfs_create_dir("clk_local", NULL);
 288         if (IS_ERR(dent_local))
 289                 return PTR_ERR(dent_local);
 290
 291         while ((clock = msm_clock_get_nth(n++)) != 0) {
 292                 strncpy(temp, clock->dbg_name, ARRAY_SIZE(temp)-1);
 293                 for (ptr = temp; *ptr; ptr++)
 294                         *ptr = tolower(*ptr);
 295                 debugfs_create_file(temp, 0644, dent_rate,
 296                                     clock, &clock_rate_fops);
 297                 debugfs_create_file(temp, 0644, dent_enable,
 298                                     clock, &clock_enable_fops);
 299                 debugfs_create_file(temp, S_IRUGO, dent_local,
 300                                     clock, &clock_local_fops);
 301         }
 302         return 0;
 303 }
 304
 305 device_initcall(clock_debug_init);
 306 #endif
 307
 308 /* The bootloader and/or AMSS may have left various clocks enabled.
 309  * Disable any clocks that belong to us (CLKFLAG_AUTO_OFF) but have
 310  * not been explicitly enabled by a clk_enable() call.
 311  */
 312 static int __init clock_late_init(void)
 313 {
 314         unsigned long flags;
 315         struct clk *clk;
 316         unsigned count = 0;
 317
 318         mutex_lock(&clocks_mutex);
 319         list_for_each_entry(clk, &clocks, list) {
 320                 if (clk->flags & CLKFLAG_AUTO_OFF) {
 321                         spin_lock_irqsave(&clocks_lock, flags);
 322                         if (!clk->count) {
 323                                 count++;
 324                                 clk->ops->auto_off(clk->id);
 325                         }
 326                         spin_unlock_irqrestore(&clocks_lock, flags);
 327                 }
 328         }
 329         mutex_unlock(&clocks_mutex);
 330         pr_info("clock_late_init() disabled %d unused clocks\n", count);
 331         return 0;
 332 }
 333
 334 late_initcall(clock_late_init);