arch/arm/mach-omap2/clockdomain.c

   1 /*
   2  * OMAP2/3/4 clockdomain framework functions
   3  *
   4  * Copyright (C) 2008-2011 Texas Instruments, Inc.
   5  * Copyright (C) 2008-2011 Nokia Corporation
   6  *
   7  * Written by Paul Walmsley and Jouni Högander
   8  * Added OMAP4 specific support by Abhijit Pagare <abhijitpagare@ti.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14 #undef DEBUG
  15
  16 #include <linux/kernel.h>
  17 #include <linux/device.h>
  18 #include <linux/list.h>
  19 #include <linux/errno.h>
  20 #include <linux/string.h>
  21 #include <linux/delay.h>
  22 #include <linux/clk.h>
  23 #include <linux/limits.h>
  24 #include <linux/err.h>
  25
  26 #include <linux/io.h>
  27
  28 #include <linux/bitops.h>
  29
  30 #include "soc.h"
  31 #include "clock.h"
  32 #include "clockdomain.h"
  33
  34 /* clkdm_list contains all registered struct clockdomains */
  35 static LIST_HEAD(clkdm_list);
  36
  37 /* array of clockdomain deps to be added/removed when clkdm in hwsup mode */
  38 static struct clkdm_autodep *autodeps;
  39
  40 static struct clkdm_ops *arch_clkdm;
  41
  42 /* Private functions */
  43
  44 static struct clockdomain *_clkdm_lookup(const char *name)
  45 {
  46         struct clockdomain *clkdm, *temp_clkdm;
  47
  48         if (!name)
  49                 return NULL;
  50
  51         clkdm = NULL;
  52
  53         list_for_each_entry(temp_clkdm, &clkdm_list, node) {
  54                 if (!strcmp(name, temp_clkdm->name)) {
  55                         clkdm = temp_clkdm;
  56                         break;
  57                 }
  58         }
  59
  60         return clkdm;
  61 }
  62
  63 /**
  64  * _clkdm_register - register a clockdomain
  65  * @clkdm: struct clockdomain * to register
  66  *
  67  * Adds a clockdomain to the internal clockdomain list.
  68  * Returns -EINVAL if given a null pointer, -EEXIST if a clockdomain is
  69  * already registered by the provided name, or 0 upon success.
  70  */
  71 static int _clkdm_register(struct clockdomain *clkdm)
  72 {
  73         struct powerdomain *pwrdm;
  74
  75         if (!clkdm || !clkdm->name)
  76                 return -EINVAL;
  77
  78         pwrdm = pwrdm_lookup(clkdm->pwrdm.name);
  79         if (!pwrdm) {
  80                 pr_err("clockdomain: %s: powerdomain %s does not exist\n",
  81                         clkdm->name, clkdm->pwrdm.name);
  82                 return -EINVAL;
  83         }
  84         clkdm->pwrdm.ptr = pwrdm;
  85
  86         /* Verify that the clockdomain is not already registered */
  87         if (_clkdm_lookup(clkdm->name))
  88                 return -EEXIST;
  89
  90         list_add(&clkdm->node, &clkdm_list);
  91
  92         pwrdm_add_clkdm(pwrdm, clkdm);
  93
  94         spin_lock_init(&clkdm->lock);
  95
  96         pr_debug("clockdomain: registered %s\n", clkdm->name);
  97
  98         return 0;
  99 }
 100
 101 /* _clkdm_deps_lookup - look up the specified clockdomain in a clkdm list */
 102 static struct clkdm_dep *_clkdm_deps_lookup(struct clockdomain *clkdm,
 103                                             struct clkdm_dep *deps)
 104 {
 105         struct clkdm_dep *cd;
 106
 107         if (!clkdm || !deps)
 108                 return ERR_PTR(-EINVAL);
 109
 110         for (cd = deps; cd->clkdm_name; cd++) {
 111                 if (!cd->clkdm && cd->clkdm_name)
 112                         cd->clkdm = _clkdm_lookup(cd->clkdm_name);
 113
 114                 if (cd->clkdm == clkdm)
 115                         break;
 116         }
 117
 118         if (!cd->clkdm_name)
 119                 return ERR_PTR(-ENOENT);
 120
 121         return cd;
 122 }
 123
 124 /*
 125  * _autodep_lookup - resolve autodep clkdm names to clkdm pointers; store
 126  * @autodep: struct clkdm_autodep * to resolve
 127  *
 128  * Resolve autodep clockdomain names to clockdomain pointers via
 129  * clkdm_lookup() and store the pointers in the autodep structure.  An
 130  * "autodep" is a clockdomain sleep/wakeup dependency that is
 131  * automatically added and removed whenever clocks in the associated
 132  * clockdomain are enabled or disabled (respectively) when the
 133  * clockdomain is in hardware-supervised mode.  Meant to be called
 134  * once at clockdomain layer initialization, since these should remain
 135  * fixed for a particular architecture.  No return value.
 136  *
 137  * XXX autodeps are deprecated and should be removed at the earliest
 138  * opportunity
 139  */
 140 static void _autodep_lookup(struct clkdm_autodep *autodep)
 141 {
 142         struct clockdomain *clkdm;
 143
 144         if (!autodep)
 145                 return;
 146
 147         clkdm = clkdm_lookup(autodep->clkdm.name);
 148         if (!clkdm) {
 149                 pr_err("clockdomain: autodeps: clockdomain %s does not exist\n",
 150                          autodep->clkdm.name);
 151                 clkdm = ERR_PTR(-ENOENT);
 152         }
 153         autodep->clkdm.ptr = clkdm;
 154 }
 155
 156 /*
 157  * _clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
 158  * @clkdm: struct clockdomain *
 159  *
 160  * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm'
 161  * in hardware-supervised mode.  Meant to be called from clock framework
 162  * when a clock inside clockdomain 'clkdm' is enabled.  No return value.
 163  *
 164  * XXX autodeps are deprecated and should be removed at the earliest
 165  * opportunity
 166  */
 167 void _clkdm_add_autodeps(struct clockdomain *clkdm)
 168 {
 169         struct clkdm_autodep *autodep;
 170
 171         if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
 172                 return;
 173
 174         for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
 175                 if (IS_ERR(autodep->clkdm.ptr))
 176                         continue;
 177
 178                 pr_debug("clockdomain: %s: adding %s sleepdep/wkdep\n",
 179                          clkdm->name, autodep->clkdm.ptr->name);
 180
 181                 clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr);
 182                 clkdm_add_wkdep(clkdm, autodep->clkdm.ptr);
 183         }
 184 }
 185
 186 /*
 187  * _clkdm_add_autodeps - remove auto sleepdeps/wkdeps from clkdm
 188  * @clkdm: struct clockdomain *
 189  *
 190  * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm'
 191  * in hardware-supervised mode.  Meant to be called from clock framework
 192  * when a clock inside clockdomain 'clkdm' is disabled.  No return value.
 193  *
 194  * XXX autodeps are deprecated and should be removed at the earliest
 195  * opportunity
 196  */
 197 void _clkdm_del_autodeps(struct clockdomain *clkdm)
 198 {
 199         struct clkdm_autodep *autodep;
 200
 201         if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
 202                 return;
 203
 204         for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
 205                 if (IS_ERR(autodep->clkdm.ptr))
 206                         continue;
 207
 208                 pr_debug("clockdomain: %s: removing %s sleepdep/wkdep\n",
 209                          clkdm->name, autodep->clkdm.ptr->name);
 210
 211                 clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr);
 212                 clkdm_del_wkdep(clkdm, autodep->clkdm.ptr);
 213         }
 214 }
 215
 216 /**
 217  * _resolve_clkdm_deps() - resolve clkdm_names in @clkdm_deps to clkdms
 218  * @clkdm: clockdomain that we are resolving dependencies for
 219  * @clkdm_deps: ptr to array of struct clkdm_deps to resolve
 220  *
 221  * Iterates through @clkdm_deps, looking up the struct clockdomain named by
 222  * clkdm_name and storing the clockdomain pointer in the struct clkdm_dep.
 223  * No return value.
 224  */
 225 static void _resolve_clkdm_deps(struct clockdomain *clkdm,
 226                                 struct clkdm_dep *clkdm_deps)
 227 {
 228         struct clkdm_dep *cd;
 229
 230         for (cd = clkdm_deps; cd && cd->clkdm_name; cd++) {
 231                 if (cd->clkdm)
 232                         continue;
 233                 cd->clkdm = _clkdm_lookup(cd->clkdm_name);
 234
 235                 WARN(!cd->clkdm, "clockdomain: %s: could not find clkdm %s while resolving dependencies - should never happen",
 236                      clkdm->name, cd->clkdm_name);
 237         }
 238 }
 239
 240 /* Public functions */
 241
 242 /**
 243  * clkdm_register_platform_funcs - register clockdomain implementation fns
 244  * @co: func pointers for arch specific implementations
 245  *
 246  * Register the list of function pointers used to implement the
 247  * clockdomain functions on different OMAP SoCs.  Should be called
 248  * before any other clkdm_register*() function.  Returns -EINVAL if
 249  * @co is null, -EEXIST if platform functions have already been
 250  * registered, or 0 upon success.
 251  */
 252 int clkdm_register_platform_funcs(struct clkdm_ops *co)
 253 {
 254         if (!co)
 255                 return -EINVAL;
 256
 257         if (arch_clkdm)
 258                 return -EEXIST;
 259
 260         arch_clkdm = co;
 261
 262         return 0;
 263 };
 264
 265 /**
 266  * clkdm_register_clkdms - register SoC clockdomains
 267  * @cs: pointer to an array of struct clockdomain to register
 268  *
 269  * Register the clockdomains available on a particular OMAP SoC.  Must
 270  * be called after clkdm_register_platform_funcs().  May be called
 271  * multiple times.  Returns -EACCES if called before
 272  * clkdm_register_platform_funcs(); -EINVAL if the argument @cs is
 273  * null; or 0 upon success.
 274  */
 275 int clkdm_register_clkdms(struct clockdomain **cs)
 276 {
 277         struct clockdomain **c = NULL;
 278
 279         if (!arch_clkdm)
 280                 return -EACCES;
 281
 282         if (!cs)
 283                 return -EINVAL;
 284
 285         for (c = cs; *c; c++)
 286                 _clkdm_register(*c);
 287
 288         return 0;
 289 }
 290
 291 /**
 292  * clkdm_register_autodeps - register autodeps (if required)
 293  * @ia: pointer to a static array of struct clkdm_autodep to register
 294  *
 295  * Register clockdomain "automatic dependencies."  These are
 296  * clockdomain wakeup and sleep dependencies that are automatically
 297  * added whenever the first clock inside a clockdomain is enabled, and
 298  * removed whenever the last clock inside a clockdomain is disabled.
 299  * These are currently only used on OMAP3 devices, and are deprecated,
 300  * since they waste energy.  However, until the OMAP2/3 IP block
 301  * enable/disable sequence can be converted to match the OMAP4
 302  * sequence, they are needed.
 303  *
 304  * Must be called only after all of the SoC clockdomains are
 305  * registered, since the function will resolve autodep clockdomain
 306  * names into clockdomain pointers.
 307  *
 308  * The struct clkdm_autodep @ia array must be static, as this function
 309  * does not copy the array elements.
 310  *
 311  * Returns -EACCES if called before any clockdomains have been
 312  * registered, -EINVAL if called with a null @ia argument, -EEXIST if
 313  * autodeps have already been registered, or 0 upon success.
 314  */
 315 int clkdm_register_autodeps(struct clkdm_autodep *ia)
 316 {
 317         struct clkdm_autodep *a = NULL;
 318
 319         if (list_empty(&clkdm_list))
 320                 return -EACCES;
 321
 322         if (!ia)
 323                 return -EINVAL;
 324
 325         if (autodeps)
 326                 return -EEXIST;
 327
 328         autodeps = ia;
 329         for (a = autodeps; a->clkdm.ptr; a++)
 330                 _autodep_lookup(a);
 331
 332         return 0;
 333 }
 334
 335 /**
 336  * clkdm_complete_init - set up the clockdomain layer
 337  *
 338  * Put all clockdomains into software-supervised mode; PM code should
 339  * later enable hardware-supervised mode as appropriate.  Must be
 340  * called after clkdm_register_clkdms().  Returns -EACCES if called
 341  * before clkdm_register_clkdms(), or 0 upon success.
 342  */
 343 int clkdm_complete_init(void)
 344 {
 345         struct clockdomain *clkdm;
 346
 347         if (list_empty(&clkdm_list))
 348                 return -EACCES;
 349
 350         list_for_each_entry(clkdm, &clkdm_list, node) {
 351                 if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
 352                         clkdm_wakeup(clkdm);
 353                 else if (clkdm->flags & CLKDM_CAN_DISABLE_AUTO)
 354                         clkdm_deny_idle(clkdm);
 355
 356                 _resolve_clkdm_deps(clkdm, clkdm->wkdep_srcs);
 357                 clkdm_clear_all_wkdeps(clkdm);
 358
 359                 _resolve_clkdm_deps(clkdm, clkdm->sleepdep_srcs);
 360                 clkdm_clear_all_sleepdeps(clkdm);
 361         }
 362
 363         return 0;
 364 }
 365
 366 /**
 367  * clkdm_lookup - look up a clockdomain by name, return a pointer
 368  * @name: name of clockdomain
 369  *
 370  * Find a registered clockdomain by its name @name.  Returns a pointer
 371  * to the struct clockdomain if found, or NULL otherwise.
 372  */
 373 struct clockdomain *clkdm_lookup(const char *name)
 374 {
 375         struct clockdomain *clkdm, *temp_clkdm;
 376
 377         if (!name)
 378                 return NULL;
 379
 380         clkdm = NULL;
 381
 382         list_for_each_entry(temp_clkdm, &clkdm_list, node) {
 383                 if (!strcmp(name, temp_clkdm->name)) {
 384                         clkdm = temp_clkdm;
 385                         break;
 386                 }
 387         }
 388
 389         return clkdm;
 390 }
 391
 392 /**
 393  * clkdm_for_each - call function on each registered clockdomain
 394  * @fn: callback function *
 395  *
 396  * Call the supplied function @fn for each registered clockdomain.
 397  * The callback function @fn can return anything but 0 to bail
 398  * out early from the iterator.  The callback function is called with
 399  * the clkdm_mutex held, so no clockdomain structure manipulation
 400  * functions should be called from the callback, although hardware
 401  * clockdomain control functions are fine.  Returns the last return
 402  * value of the callback function, which should be 0 for success or
 403  * anything else to indicate failure; or -EINVAL if the function pointer
 404  * is null.
 405  */
 406 int clkdm_for_each(int (*fn)(struct clockdomain *clkdm, void *user),
 407                         void *user)
 408 {
 409         struct clockdomain *clkdm;
 410         int ret = 0;
 411
 412         if (!fn)
 413                 return -EINVAL;
 414
 415         list_for_each_entry(clkdm, &clkdm_list, node) {
 416                 ret = (*fn)(clkdm, user);
 417                 if (ret)
 418                         break;
 419         }
 420
 421         return ret;
 422 }
 423
 424
 425 /**
 426  * clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in
 427  * @clkdm: struct clockdomain *
 428  *
 429  * Return a pointer to the struct powerdomain that the specified clockdomain
 430  * @clkdm exists in, or returns NULL if @clkdm is NULL.
 431  */
 432 struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
 433 {
 434         if (!clkdm)
 435                 return NULL;
 436
 437         return clkdm->pwrdm.ptr;
 438 }
 439
 440
 441 /* Hardware clockdomain control */
 442
 443 /**
 444  * clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1
 445  * @clkdm1: wake this struct clockdomain * up (dependent)
 446  * @clkdm2: when this struct clockdomain * wakes up (source)
 447  *
 448  * When the clockdomain represented by @clkdm2 wakes up, wake up
 449  * @clkdm1. Implemented in hardware on the OMAP, this feature is
 450  * designed to reduce wakeup latency of the dependent clockdomain @clkdm1.
 451  * Returns -EINVAL if presented with invalid clockdomain pointers,
 452  * -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 0 upon
 453  * success.
 454  */
 455 int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 456 {
 457         struct clkdm_dep *cd;
 458         int ret = 0;
 459
 460         if (!clkdm1 || !clkdm2)
 461                 return -EINVAL;
 462
 463         cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
 464         if (IS_ERR(cd))
 465                 ret = PTR_ERR(cd);
 466
 467         if (!arch_clkdm || !arch_clkdm->clkdm_add_wkdep)
 468                 ret = -EINVAL;
 469
 470         if (ret) {
 471                 pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n",
 472                          clkdm1->name, clkdm2->name);
 473                 return ret;
 474         }
 475
 476         if (atomic_inc_return(&cd->wkdep_usecount) == 1) {
 477                 pr_debug("clockdomain: hardware will wake up %s when %s wakes up\n",
 478                          clkdm1->name, clkdm2->name);
 479
 480                 ret = arch_clkdm->clkdm_add_wkdep(clkdm1, clkdm2);
 481         }
 482
 483         return ret;
 484 }
 485
 486 /**
 487  * clkdm_del_wkdep - remove a wakeup dependency from clkdm2 to clkdm1
 488  * @clkdm1: wake this struct clockdomain * up (dependent)
 489  * @clkdm2: when this struct clockdomain * wakes up (source)
 490  *
 491  * Remove a wakeup dependency causing @clkdm1 to wake up when @clkdm2
 492  * wakes up.  Returns -EINVAL if presented with invalid clockdomain
 493  * pointers, -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or
 494  * 0 upon success.
 495  */
 496 int clkdm_del_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 497 {
 498         struct clkdm_dep *cd;
 499         int ret = 0;
 500
 501         if (!clkdm1 || !clkdm2)
 502                 return -EINVAL;
 503
 504         cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
 505         if (IS_ERR(cd))
 506                 ret = PTR_ERR(cd);
 507
 508         if (!arch_clkdm || !arch_clkdm->clkdm_del_wkdep)
 509                 ret = -EINVAL;
 510
 511         if (ret) {
 512                 pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n",
 513                          clkdm1->name, clkdm2->name);
 514                 return ret;
 515         }
 516
 517         if (atomic_dec_return(&cd->wkdep_usecount) == 0) {
 518                 pr_debug("clockdomain: hardware will no longer wake up %s after %s wakes up\n",
 519                          clkdm1->name, clkdm2->name);
 520
 521                 ret = arch_clkdm->clkdm_del_wkdep(clkdm1, clkdm2);
 522         }
 523
 524         return ret;
 525 }
 526
 527 /**
 528  * clkdm_read_wkdep - read wakeup dependency state from clkdm2 to clkdm1
 529  * @clkdm1: wake this struct clockdomain * up (dependent)
 530  * @clkdm2: when this struct clockdomain * wakes up (source)
 531  *
 532  * Return 1 if a hardware wakeup dependency exists wherein @clkdm1 will be
 533  * awoken when @clkdm2 wakes up; 0 if dependency is not set; -EINVAL
 534  * if either clockdomain pointer is invalid; or -ENOENT if the hardware
 535  * is incapable.
 536  *
 537  * REVISIT: Currently this function only represents software-controllable
 538  * wakeup dependencies.  Wakeup dependencies fixed in hardware are not
 539  * yet handled here.
 540  */
 541 int clkdm_read_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 542 {
 543         struct clkdm_dep *cd;
 544         int ret = 0;
 545
 546         if (!clkdm1 || !clkdm2)
 547                 return -EINVAL;
 548
 549         cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
 550         if (IS_ERR(cd))
 551                 ret = PTR_ERR(cd);
 552
 553         if (!arch_clkdm || !arch_clkdm->clkdm_read_wkdep)
 554                 ret = -EINVAL;
 555
 556         if (ret) {
 557                 pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n",
 558                          clkdm1->name, clkdm2->name);
 559                 return ret;
 560         }
 561
 562         /* XXX It's faster to return the atomic wkdep_usecount */
 563         return arch_clkdm->clkdm_read_wkdep(clkdm1, clkdm2);
 564 }
 565
 566 /**
 567  * clkdm_clear_all_wkdeps - remove all wakeup dependencies from target clkdm
 568  * @clkdm: struct clockdomain * to remove all wakeup dependencies from
 569  *
 570  * Remove all inter-clockdomain wakeup dependencies that could cause
 571  * @clkdm to wake.  Intended to be used during boot to initialize the
 572  * PRCM to a known state, after all clockdomains are put into swsup idle
 573  * and woken up.  Returns -EINVAL if @clkdm pointer is invalid, or
 574  * 0 upon success.
 575  */
 576 int clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
 577 {
 578         if (!clkdm)
 579                 return -EINVAL;
 580
 581         if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_wkdeps)
 582                 return -EINVAL;
 583
 584         return arch_clkdm->clkdm_clear_all_wkdeps(clkdm);
 585 }
 586
 587 /**
 588  * clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1
 589  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
 590  * @clkdm2: when this struct clockdomain * is active (source)
 591  *
 592  * Prevent @clkdm1 from automatically going inactive (and then to
 593  * retention or off) if @clkdm2 is active.  Returns -EINVAL if
 594  * presented with invalid clockdomain pointers or called on a machine
 595  * that does not support software-configurable hardware sleep
 596  * dependencies, -ENOENT if the specified dependency cannot be set in
 597  * hardware, or 0 upon success.
 598  */
 599 int clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 600 {
 601         struct clkdm_dep *cd;
 602         int ret = 0;
 603
 604         if (!clkdm1 || !clkdm2)
 605                 return -EINVAL;
 606
 607         cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
 608         if (IS_ERR(cd))
 609                 ret = PTR_ERR(cd);
 610
 611         if (!arch_clkdm || !arch_clkdm->clkdm_add_sleepdep)
 612                 ret = -EINVAL;
 613
 614         if (ret) {
 615                 pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n",
 616                          clkdm1->name, clkdm2->name);
 617                 return ret;
 618         }
 619
 620         if (atomic_inc_return(&cd->sleepdep_usecount) == 1) {
 621                 pr_debug("clockdomain: will prevent %s from sleeping if %s is active\n",
 622                          clkdm1->name, clkdm2->name);
 623
 624                 ret = arch_clkdm->clkdm_add_sleepdep(clkdm1, clkdm2);
 625         }
 626
 627         return ret;
 628 }
 629
 630 /**
 631  * clkdm_del_sleepdep - remove a sleep dependency from clkdm2 to clkdm1
 632  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
 633  * @clkdm2: when this struct clockdomain * is active (source)
 634  *
 635  * Allow @clkdm1 to automatically go inactive (and then to retention or
 636  * off), independent of the activity state of @clkdm2.  Returns -EINVAL
 637  * if presented with invalid clockdomain pointers or called on a machine
 638  * that does not support software-configurable hardware sleep dependencies,
 639  * -ENOENT if the specified dependency cannot be cleared in hardware, or
 640  * 0 upon success.
 641  */
 642 int clkdm_del_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 643 {
 644         struct clkdm_dep *cd;
 645         int ret = 0;
 646
 647         if (!clkdm1 || !clkdm2)
 648                 return -EINVAL;
 649
 650         cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
 651         if (IS_ERR(cd))
 652                 ret = PTR_ERR(cd);
 653
 654         if (!arch_clkdm || !arch_clkdm->clkdm_del_sleepdep)
 655                 ret = -EINVAL;
 656
 657         if (ret) {
 658                 pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n",
 659                          clkdm1->name, clkdm2->name);
 660                 return ret;
 661         }
 662
 663         if (atomic_dec_return(&cd->sleepdep_usecount) == 0) {
 664                 pr_debug("clockdomain: will no longer prevent %s from sleeping if %s is active\n",
 665                          clkdm1->name, clkdm2->name);
 666
 667                 ret = arch_clkdm->clkdm_del_sleepdep(clkdm1, clkdm2);
 668         }
 669
 670         return ret;
 671 }
 672
 673 /**
 674  * clkdm_read_sleepdep - read sleep dependency state from clkdm2 to clkdm1
 675  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
 676  * @clkdm2: when this struct clockdomain * is active (source)
 677  *
 678  * Return 1 if a hardware sleep dependency exists wherein @clkdm1 will
 679  * not be allowed to automatically go inactive if @clkdm2 is active;
 680  * 0 if @clkdm1's automatic power state inactivity transition is independent
 681  * of @clkdm2's; -EINVAL if either clockdomain pointer is invalid or called
 682  * on a machine that does not support software-configurable hardware sleep
 683  * dependencies; or -ENOENT if the hardware is incapable.
 684  *
 685  * REVISIT: Currently this function only represents software-controllable
 686  * sleep dependencies.  Sleep dependencies fixed in hardware are not
 687  * yet handled here.
 688  */
 689 int clkdm_read_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 690 {
 691         struct clkdm_dep *cd;
 692         int ret = 0;
 693
 694         if (!clkdm1 || !clkdm2)
 695                 return -EINVAL;
 696
 697         cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
 698         if (IS_ERR(cd))
 699                 ret = PTR_ERR(cd);
 700
 701         if (!arch_clkdm || !arch_clkdm->clkdm_read_sleepdep)
 702                 ret = -EINVAL;
 703
 704         if (ret) {
 705                 pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n",
 706                          clkdm1->name, clkdm2->name);
 707                 return ret;
 708         }
 709
 710         /* XXX It's faster to return the atomic sleepdep_usecount */
 711         return arch_clkdm->clkdm_read_sleepdep(clkdm1, clkdm2);
 712 }
 713
 714 /**
 715  * clkdm_clear_all_sleepdeps - remove all sleep dependencies from target clkdm
 716  * @clkdm: struct clockdomain * to remove all sleep dependencies from
 717  *
 718  * Remove all inter-clockdomain sleep dependencies that could prevent
 719  * @clkdm from idling.  Intended to be used during boot to initialize the
 720  * PRCM to a known state, after all clockdomains are put into swsup idle
 721  * and woken up.  Returns -EINVAL if @clkdm pointer is invalid, or
 722  * 0 upon success.
 723  */
 724 int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm)
 725 {
 726         if (!clkdm)
 727                 return -EINVAL;
 728
 729         if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_sleepdeps)
 730                 return -EINVAL;
 731
 732         return arch_clkdm->clkdm_clear_all_sleepdeps(clkdm);
 733 }
 734
 735 /**
 736  * clkdm_sleep - force clockdomain sleep transition
 737  * @clkdm: struct clockdomain *
 738  *
 739  * Instruct the CM to force a sleep transition on the specified
 740  * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if
 741  * clockdomain does not support software-initiated sleep; 0 upon
 742  * success.
 743  */
 744 int clkdm_sleep(struct clockdomain *clkdm)
 745 {
 746         int ret;
 747         unsigned long flags;
 748
 749         if (!clkdm)
 750                 return -EINVAL;
 751
 752         if (!(clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) {
 753                 pr_debug("clockdomain: %s does not support forcing sleep via software\n",
 754                          clkdm->name);
 755                 return -EINVAL;
 756         }
 757
 758         if (!arch_clkdm || !arch_clkdm->clkdm_sleep)
 759                 return -EINVAL;
 760
 761         pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name);
 762
 763         spin_lock_irqsave(&clkdm->lock, flags);
 764         clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
 765         ret = arch_clkdm->clkdm_sleep(clkdm);
 766         spin_unlock_irqrestore(&clkdm->lock, flags);
 767         return ret;
 768 }
 769
 770 /**
 771  * clkdm_wakeup - force clockdomain wakeup transition
 772  * @clkdm: struct clockdomain *
 773  *
 774  * Instruct the CM to force a wakeup transition on the specified
 775  * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if the
 776  * clockdomain does not support software-controlled wakeup; 0 upon
 777  * success.
 778  */
 779 int clkdm_wakeup(struct clockdomain *clkdm)
 780 {
 781         int ret;
 782         unsigned long flags;
 783
 784         if (!clkdm)
 785                 return -EINVAL;
 786
 787         if (!(clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)) {
 788                 pr_debug("clockdomain: %s does not support forcing wakeup via software\n",
 789                          clkdm->name);
 790                 return -EINVAL;
 791         }
 792
 793         if (!arch_clkdm || !arch_clkdm->clkdm_wakeup)
 794                 return -EINVAL;
 795
 796         pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name);
 797
 798         spin_lock_irqsave(&clkdm->lock, flags);
 799         clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
 800         ret = arch_clkdm->clkdm_wakeup(clkdm);
 801         ret |= pwrdm_state_switch(clkdm->pwrdm.ptr);
 802         spin_unlock_irqrestore(&clkdm->lock, flags);
 803         return ret;
 804 }
 805
 806 /**
 807  * clkdm_allow_idle - enable hwsup idle transitions for clkdm
 808  * @clkdm: struct clockdomain *
 809  *
 810  * Allow the hardware to automatically switch the clockdomain @clkdm into
 811  * active or idle states, as needed by downstream clocks.  If the
 812  * clockdomain has any downstream clocks enabled in the clock
 813  * framework, wkdep/sleepdep autodependencies are added; this is so
 814  * device drivers can read and write to the device.  No return value.
 815  */
 816 void clkdm_allow_idle(struct clockdomain *clkdm)
 817 {
 818         unsigned long flags;
 819
 820         if (!clkdm)
 821                 return;
 822
 823         if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO)) {
 824                 pr_debug("clock: %s: automatic idle transitions cannot be enabled\n",
 825                          clkdm->name);
 826                 return;
 827         }
 828
 829         if (!arch_clkdm || !arch_clkdm->clkdm_allow_idle)
 830                 return;
 831
 832         pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
 833                  clkdm->name);
 834
 835         spin_lock_irqsave(&clkdm->lock, flags);
 836         clkdm->_flags |= _CLKDM_FLAG_HWSUP_ENABLED;
 837         arch_clkdm->clkdm_allow_idle(clkdm);
 838         pwrdm_state_switch(clkdm->pwrdm.ptr);
 839         spin_unlock_irqrestore(&clkdm->lock, flags);
 840 }
 841
 842 /**
 843  * clkdm_deny_idle - disable hwsup idle transitions for clkdm
 844  * @clkdm: struct clockdomain *
 845  *
 846  * Prevent the hardware from automatically switching the clockdomain
 847  * @clkdm into inactive or idle states.  If the clockdomain has
 848  * downstream clocks enabled in the clock framework, wkdep/sleepdep
 849  * autodependencies are removed.  No return value.
 850  */
 851 void clkdm_deny_idle(struct clockdomain *clkdm)
 852 {
 853         unsigned long flags;
 854
 855         if (!clkdm)
 856                 return;
 857
 858         if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO)) {
 859                 pr_debug("clockdomain: %s: automatic idle transitions cannot be disabled\n",
 860                          clkdm->name);
 861                 return;
 862         }
 863
 864         if (!arch_clkdm || !arch_clkdm->clkdm_deny_idle)
 865                 return;
 866
 867         pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
 868                  clkdm->name);
 869
 870         spin_lock_irqsave(&clkdm->lock, flags);
 871         clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
 872         arch_clkdm->clkdm_deny_idle(clkdm);
 873         pwrdm_state_switch(clkdm->pwrdm.ptr);
 874         spin_unlock_irqrestore(&clkdm->lock, flags);
 875 }
 876
 877 /**
 878  * clkdm_in_hwsup - is clockdomain @clkdm have hardware-supervised idle enabled?
 879  * @clkdm: struct clockdomain *
 880  *
 881  * Returns true if clockdomain @clkdm currently has
 882  * hardware-supervised idle enabled, or false if it does not or if
 883  * @clkdm is NULL.  It is only valid to call this function after
 884  * clkdm_init() has been called.  This function does not actually read
 885  * bits from the hardware; it instead tests an in-memory flag that is
 886  * changed whenever the clockdomain code changes the auto-idle mode.
 887  */
 888 bool clkdm_in_hwsup(struct clockdomain *clkdm)
 889 {
 890         bool ret;
 891         unsigned long flags;
 892
 893         if (!clkdm)
 894                 return false;
 895
 896         spin_lock_irqsave(&clkdm->lock, flags);
 897         ret = (clkdm->_flags & _CLKDM_FLAG_HWSUP_ENABLED) ? true : false;
 898         spin_unlock_irqrestore(&clkdm->lock, flags);
 899
 900         return ret;
 901 }
 902
 903 /**
 904  * clkdm_missing_idle_reporting - can @clkdm enter autoidle even if in use?
 905  * @clkdm: struct clockdomain *
 906  *
 907  * Returns true if clockdomain @clkdm has the
 908  * CLKDM_MISSING_IDLE_REPORTING flag set, or false if not or @clkdm is
 909  * null.  More information is available in the documentation for the
 910  * CLKDM_MISSING_IDLE_REPORTING macro.
 911  */
 912 bool clkdm_missing_idle_reporting(struct clockdomain *clkdm)
 913 {
 914         if (!clkdm)
 915                 return false;
 916
 917         return (clkdm->flags & CLKDM_MISSING_IDLE_REPORTING) ? true : false;
 918 }
 919
 920 /* Clockdomain-to-clock/hwmod framework interface code */
 921
 922 static int _clkdm_clk_hwmod_enable(struct clockdomain *clkdm)
 923 {
 924         unsigned long flags;
 925
 926         if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_enable)
 927                 return -EINVAL;
 928
 929         /*
 930          * For arch's with no autodeps, clkcm_clk_enable
 931          * should be called for every clock instance or hwmod that is
 932          * enabled, so the clkdm can be force woken up.
 933          */
 934         if ((atomic_inc_return(&clkdm->usecount) > 1) && autodeps)
 935                 return 0;
 936
 937         spin_lock_irqsave(&clkdm->lock, flags);
 938         arch_clkdm->clkdm_clk_enable(clkdm);
 939         pwrdm_state_switch(clkdm->pwrdm.ptr);
 940         spin_unlock_irqrestore(&clkdm->lock, flags);
 941
 942         pr_debug("clockdomain: %s: enabled\n", clkdm->name);
 943
 944         return 0;
 945 }
 946
 947 static int _clkdm_clk_hwmod_disable(struct clockdomain *clkdm)
 948 {
 949         unsigned long flags;
 950
 951         if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_disable)
 952                 return -EINVAL;
 953
 954         if (atomic_read(&clkdm->usecount) == 0) {
 955                 WARN_ON(1); /* underflow */
 956                 return -ERANGE;
 957         }
 958
 959         if (atomic_dec_return(&clkdm->usecount) > 0)
 960                 return 0;
 961
 962         spin_lock_irqsave(&clkdm->lock, flags);
 963         arch_clkdm->clkdm_clk_disable(clkdm);
 964         pwrdm_state_switch(clkdm->pwrdm.ptr);
 965         spin_unlock_irqrestore(&clkdm->lock, flags);
 966
 967         pr_debug("clockdomain: %s: disabled\n", clkdm->name);
 968
 969         return 0;
 970 }
 971
 972 /**
 973  * clkdm_clk_enable - add an enabled downstream clock to this clkdm
 974  * @clkdm: struct clockdomain *
 975  * @clk: struct clk * of the enabled downstream clock
 976  *
 977  * Increment the usecount of the clockdomain @clkdm and ensure that it
 978  * is awake before @clk is enabled.  Intended to be called by
 979  * clk_enable() code.  If the clockdomain is in software-supervised
 980  * idle mode, force the clockdomain to wake.  If the clockdomain is in
 981  * hardware-supervised idle mode, add clkdm-pwrdm autodependencies, to
 982  * ensure that devices in the clockdomain can be read from/written to
 983  * by on-chip processors.  Returns -EINVAL if passed null pointers;
 984  * returns 0 upon success or if the clockdomain is in hwsup idle mode.
 985  */
 986 int clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
 987 {
 988         /*
 989          * XXX Rewrite this code to maintain a list of enabled
 990          * downstream clocks for debugging purposes?
 991          */
 992
 993         if (!clk)
 994                 return -EINVAL;
 995
 996         return _clkdm_clk_hwmod_enable(clkdm);
 997 }
 998
 999 /**
1000  * clkdm_clk_disable - remove an enabled downstream clock from this clkdm
1001  * @clkdm: struct clockdomain *
1002  * @clk: struct clk * of the disabled downstream clock
1003  *
1004  * Decrement the usecount of this clockdomain @clkdm when @clk is
1005  * disabled.  Intended to be called by clk_disable() code.  If the
1006  * clockdomain usecount goes to 0, put the clockdomain to sleep
1007  * (software-supervised mode) or remove the clkdm autodependencies
1008  * (hardware-supervised mode).  Returns -EINVAL if passed null
1009  * pointers; -ERANGE if the @clkdm usecount underflows; or returns 0
1010  * upon success or if the clockdomain is in hwsup idle mode.
1011  */
1012 int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
1013 {
1014         /*
1015          * XXX Rewrite this code to maintain a list of enabled
1016          * downstream clocks for debugging purposes?
1017          */
1018
1019         if (!clk)
1020                 return -EINVAL;
1021
1022         return _clkdm_clk_hwmod_disable(clkdm);
1023 }
1024
1025 /**
1026  * clkdm_hwmod_enable - add an enabled downstream hwmod to this clkdm
1027  * @clkdm: struct clockdomain *
1028  * @oh: struct omap_hwmod * of the enabled downstream hwmod
1029  *
1030  * Increment the usecount of the clockdomain @clkdm and ensure that it
1031  * is awake before @oh is enabled. Intended to be called by
1032  * module_enable() code.
1033  * If the clockdomain is in software-supervised idle mode, force the
1034  * clockdomain to wake.  If the clockdomain is in hardware-supervised idle
1035  * mode, add clkdm-pwrdm autodependencies, to ensure that devices in the
1036  * clockdomain can be read from/written to by on-chip processors.
1037  * Returns -EINVAL if passed null pointers;
1038  * returns 0 upon success or if the clockdomain is in hwsup idle mode.
1039  */
1040 int clkdm_hwmod_enable(struct clockdomain *clkdm, struct omap_hwmod *oh)
1041 {
1042         /* The clkdm attribute does not exist yet prior OMAP4 */
1043         if (cpu_is_omap24xx() || cpu_is_omap34xx())
1044                 return 0;
1045
1046         /*
1047          * XXX Rewrite this code to maintain a list of enabled
1048          * downstream hwmods for debugging purposes?
1049          */
1050
1051         if (!oh)
1052                 return -EINVAL;
1053
1054         return _clkdm_clk_hwmod_enable(clkdm);
1055 }
1056
1057 /**
1058  * clkdm_hwmod_disable - remove an enabled downstream hwmod from this clkdm
1059  * @clkdm: struct clockdomain *
1060  * @oh: struct omap_hwmod * of the disabled downstream hwmod
1061  *
1062  * Decrement the usecount of this clockdomain @clkdm when @oh is
1063  * disabled. Intended to be called by module_disable() code.
1064  * If the clockdomain usecount goes to 0, put the clockdomain to sleep
1065  * (software-supervised mode) or remove the clkdm autodependencies
1066  * (hardware-supervised mode).
1067  * Returns -EINVAL if passed null pointers; -ERANGE if the @clkdm usecount
1068  * underflows; or returns 0 upon success or if the clockdomain is in hwsup
1069  * idle mode.
1070  */
1071 int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh)
1072 {
1073         /* The clkdm attribute does not exist yet prior OMAP4 */
1074         if (cpu_is_omap24xx() || cpu_is_omap34xx())
1075                 return 0;
1076
1077         /*
1078          * XXX Rewrite this code to maintain a list of enabled
1079          * downstream hwmods for debugging purposes?
1080          */
1081
1082         if (!oh)
1083                 return -EINVAL;
1084
1085         return _clkdm_clk_hwmod_disable(clkdm);
1086 }
1087