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         int ret;
 124         if (clk->flags & CLKFLAG_MAX) {
 125                 ret = clk->ops->set_max_rate(clk->id, rate);
 126                 if (ret)
 127                         return ret;
 128         }
 129         if (clk->flags & CLKFLAG_MIN) {
 130                 ret = clk->ops->set_min_rate(clk->id, rate);
 131                 if (ret)
 132                         return ret;
 133         }
 134
 135         if (clk->flags & CLKFLAG_MAX || clk->flags & CLKFLAG_MIN)
 136                 return ret;
 137
 138         return clk->ops->set_rate(clk->id, rate);
 139 }
 140 EXPORT_SYMBOL(clk_set_rate);
 141
 142 long clk_round_rate(struct clk *clk, unsigned long rate)
 143 {
 144         return clk->ops->round_rate(clk->id, rate);
 145 }
 146 EXPORT_SYMBOL(clk_round_rate);
 147
 148 int clk_set_min_rate(struct clk *clk, unsigned long rate)
 149 {
 150         return clk->ops->set_min_rate(clk->id, rate);
 151 }
 152 EXPORT_SYMBOL(clk_set_min_rate);
 153
 154 int clk_set_max_rate(struct clk *clk, unsigned long rate)
 155 {
 156         return clk->ops->set_max_rate(clk->id, rate);
 157 }
 158 EXPORT_SYMBOL(clk_set_max_rate);
 159
 160 int clk_set_parent(struct clk *clk, struct clk *parent)
 161 {
 162         return -ENOSYS;
 163 }
 164 EXPORT_SYMBOL(clk_set_parent);
 165
 166 struct clk *clk_get_parent(struct clk *clk)
 167 {
 168         return ERR_PTR(-ENOSYS);
 169 }
 170 EXPORT_SYMBOL(clk_get_parent);
 171
 172 int clk_set_flags(struct clk *clk, unsigned long flags)
 173 {
 174         if (clk == NULL || IS_ERR(clk))
 175                 return -EINVAL;
 176         return clk->ops->set_flags(clk->id, flags);
 177 }
 178 EXPORT_SYMBOL(clk_set_flags);
 179
 180 /* EBI1 is the only shared clock that several clients want to vote on as of
 181  * this commit. If this changes in the future, then it might be better to
 182  * make clk_min_rate handle the voting or make ebi1_clk_set_min_rate more
 183  * generic to support different clocks.
 184  */
 185 static struct clk *ebi1_clk;
 186
 187 static void __init set_clock_ops(struct clk *clk)
 188 {
 189         if (!clk->ops) {
 190                 clk->ops = &clk_ops_pcom;
 191                 clk->id = clk->remote_id;
 192         }
 193 }
 194
 195 void __init msm_clock_init(struct clk *clock_tbl, unsigned num_clocks)
 196 {
 197         unsigned n;
 198
 199         spin_lock_init(&clocks_lock);
 200         mutex_lock(&clocks_mutex);
 201         msm_clocks = clock_tbl;
 202         msm_num_clocks = num_clocks;
 203         for (n = 0; n < msm_num_clocks; n++) {
 204                 set_clock_ops(&msm_clocks[n]);
 205                 list_add_tail(&msm_clocks[n].list, &clocks);
 206         }
 207         mutex_unlock(&clocks_mutex);
 208
 209         ebi1_clk = clk_get(NULL, "ebi1_clk");
 210         BUG_ON(ebi1_clk == NULL);
 211
 212 }
 213
 214 #if defined(CONFIG_DEBUG_FS)
 215 static struct clk *msm_clock_get_nth(unsigned index)
 216 {
 217         if (index < msm_num_clocks)
 218                 return msm_clocks + index;
 219         else
 220                 return 0;
 221 }
 222
 223 static int clock_debug_rate_set(void *data, u64 val)
 224 {
 225         struct clk *clock = data;
 226         int ret;
 227
 228         /* Only increases to max rate will succeed, but that's actually good
 229          * for debugging purposes. So we don't check for error. */
 230         if (clock->flags & CLK_MAX)
 231                 clk_set_max_rate(clock, val);
 232         if (clock->flags & CLK_MIN)
 233                 ret = clk_set_min_rate(clock, val);
 234         else
 235                 ret = clk_set_rate(clock, val);
 236         if (ret != 0)
 237                 printk(KERN_ERR "clk_set%s_rate failed (%d)\n",
 238                         (clock->flags & CLK_MIN) ? "_min" : "", ret);
 239         return ret;
 240 }
 241
 242 static int clock_debug_rate_get(void *data, u64 *val)
 243 {
 244         struct clk *clock = data;
 245         *val = clk_get_rate(clock);
 246         return 0;
 247 }
 248
 249 static int clock_debug_enable_set(void *data, u64 val)
 250 {
 251         struct clk *clock = data;
 252         int rc = 0;
 253
 254         if (val)
 255                 rc = clock->ops->enable(clock->id);
 256         else
 257                 clock->ops->disable(clock->id);
 258
 259         return rc;
 260 }
 261
 262 static int clock_debug_enable_get(void *data, u64 *val)
 263 {
 264         struct clk *clock = data;
 265
 266         *val = clock->ops->is_enabled(clock->id);
 267
 268         return 0;
 269 }
 270
 271 static int clock_debug_local_get(void *data, u64 *val)
 272 {
 273         struct clk *clock = data;
 274
 275         *val = clock->ops != &clk_ops_pcom;
 276
 277         return 0;
 278 }
 279
 280 DEFINE_SIMPLE_ATTRIBUTE(clock_rate_fops, clock_debug_rate_get,
 281                         clock_debug_rate_set, "%llu\n");
 282 DEFINE_SIMPLE_ATTRIBUTE(clock_enable_fops, clock_debug_enable_get,
 283                         clock_debug_enable_set, "%llu\n");
 284 DEFINE_SIMPLE_ATTRIBUTE(clock_local_fops, clock_debug_local_get,
 285                         NULL, "%llu\n");
 286
 287 static int __init clock_debug_init(void)
 288 {
 289         struct dentry *dent_rate, *dent_enable, *dent_local;
 290         struct clk *clock;
 291         unsigned n = 0;
 292         char temp[50], *ptr;
 293
 294         dent_rate = debugfs_create_dir("clk_rate", 0);
 295         if (IS_ERR(dent_rate))
 296                 return PTR_ERR(dent_rate);
 297
 298         dent_enable = debugfs_create_dir("clk_enable", 0);
 299         if (IS_ERR(dent_enable))
 300                 return PTR_ERR(dent_enable);
 301
 302         dent_local = debugfs_create_dir("clk_local", NULL);
 303         if (IS_ERR(dent_local))
 304                 return PTR_ERR(dent_local);
 305
 306         while ((clock = msm_clock_get_nth(n++)) != 0) {
 307                 strncpy(temp, clock->dbg_name, ARRAY_SIZE(temp)-1);
 308                 for (ptr = temp; *ptr; ptr++)
 309                         *ptr = tolower(*ptr);
 310                 debugfs_create_file(temp, 0644, dent_rate,
 311                                     clock, &clock_rate_fops);
 312                 debugfs_create_file(temp, 0644, dent_enable,
 313                                     clock, &clock_enable_fops);
 314                 debugfs_create_file(temp, S_IRUGO, dent_local,
 315                                     clock, &clock_local_fops);
 316         }
 317         return 0;
 318 }
 319
 320 device_initcall(clock_debug_init);
 321 #endif
 322
 323 /* The bootloader and/or AMSS may have left various clocks enabled.
 324  * Disable any clocks that belong to us (CLKFLAG_AUTO_OFF) but have
 325  * not been explicitly enabled by a clk_enable() call.
 326  */
 327 static int __init clock_late_init(void)
 328 {
 329         unsigned long flags;
 330         struct clk *clk;
 331         unsigned count = 0;
 332
 333         mutex_lock(&clocks_mutex);
 334         list_for_each_entry(clk, &clocks, list) {
 335                 if (clk->flags & CLKFLAG_AUTO_OFF) {
 336                         spin_lock_irqsave(&clocks_lock, flags);
 337                         if (!clk->count) {
 338                                 count++;
 339                                 clk->ops->auto_off(clk->id);
 340                         }
 341                         spin_unlock_irqrestore(&clocks_lock, flags);
 342                 }
 343         }
 344         mutex_unlock(&clocks_mutex);
 345         pr_info("clock_late_init() disabled %d unused clocks\n", count);
 346         return 0;
 347 }
 348
 349 late_initcall(clock_late_init);
 350