1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * OMAP2/3/4 clockdomain framework functions
   4 *
   5 * Copyright (C) 2008-2011 Texas Instruments, Inc.
   6 * Copyright (C) 2008-2011 Nokia Corporation
   7 *
   8 * Written by Paul Walmsley and Jouni Högander
   9 * Added OMAP4 specific support by Abhijit Pagare <abhijitpagare@ti.com>
  10 */
  11#undef DEBUG
  12
  13#include <linux/kernel.h>
  14#include <linux/device.h>
  15#include <linux/list.h>
  16#include <linux/errno.h>
  17#include <linux/string.h>
  18#include <linux/delay.h>
  19#include <linux/clk.h>
  20#include <linux/limits.h>
  21#include <linux/err.h>
  22#include <linux/clk-provider.h>
  23#include <linux/cpu_pm.h>
  24
  25#include <linux/io.h>
  26
  27#include <linux/bitops.h>
  28
  29#include "soc.h"
  30#include "clock.h"
  31#include "clockdomain.h"
  32#include "pm.h"
  33
  34/* clkdm_list contains all registered struct clockdomains */
  35static LIST_HEAD(clkdm_list);
  36
  37/* array of clockdomain deps to be added/removed when clkdm in hwsup mode */
  38static struct clkdm_autodep *autodeps;
  39
  40static struct clkdm_ops *arch_clkdm;
  41void clkdm_save_context(void);
  42void clkdm_restore_context(void);
  43
  44/* Private functions */
  45
  46static struct clockdomain *_clkdm_lookup(const char *name)
  47{
  48	struct clockdomain *clkdm, *temp_clkdm;
  49
  50	if (!name)
  51		return NULL;
  52
  53	clkdm = NULL;
  54
  55	list_for_each_entry(temp_clkdm, &clkdm_list, node) {
  56		if (!strcmp(name, temp_clkdm->name)) {
  57			clkdm = temp_clkdm;
  58			break;
  59		}
  60	}
  61
  62	return clkdm;
  63}
  64
  65/**
  66 * _clkdm_register - register a clockdomain
  67 * @clkdm: struct clockdomain * to register
  68 *
  69 * Adds a clockdomain to the internal clockdomain list.
  70 * Returns -EINVAL if given a null pointer, -EEXIST if a clockdomain is
  71 * already registered by the provided name, or 0 upon success.
  72 */
  73static int _clkdm_register(struct clockdomain *clkdm)
  74{
  75	struct powerdomain *pwrdm;
  76
  77	if (!clkdm || !clkdm->name)
  78		return -EINVAL;
  79
  80	pwrdm = pwrdm_lookup(clkdm->pwrdm.name);
  81	if (!pwrdm) {
  82		pr_err("clockdomain: %s: powerdomain %s does not exist\n",
  83			clkdm->name, clkdm->pwrdm.name);
  84		return -EINVAL;
  85	}
  86	clkdm->pwrdm.ptr = pwrdm;
  87
  88	/* Verify that the clockdomain is not already registered */
  89	if (_clkdm_lookup(clkdm->name))
  90		return -EEXIST;
  91
  92	list_add(&clkdm->node, &clkdm_list);
  93
  94	pwrdm_add_clkdm(pwrdm, clkdm);
  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 */
 102static 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 */
 140static 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 * _resolve_clkdm_deps() - resolve clkdm_names in @clkdm_deps to clkdms
 158 * @clkdm: clockdomain that we are resolving dependencies for
 159 * @clkdm_deps: ptr to array of struct clkdm_deps to resolve
 160 *
 161 * Iterates through @clkdm_deps, looking up the struct clockdomain named by
 162 * clkdm_name and storing the clockdomain pointer in the struct clkdm_dep.
 163 * No return value.
 164 */
 165static void _resolve_clkdm_deps(struct clockdomain *clkdm,
 166				struct clkdm_dep *clkdm_deps)
 167{
 168	struct clkdm_dep *cd;
 169
 170	for (cd = clkdm_deps; cd && cd->clkdm_name; cd++) {
 171		if (cd->clkdm)
 172			continue;
 173		cd->clkdm = _clkdm_lookup(cd->clkdm_name);
 174
 175		WARN(!cd->clkdm, "clockdomain: %s: could not find clkdm %s while resolving dependencies - should never happen",
 176		     clkdm->name, cd->clkdm_name);
 177	}
 178}
 179
 180/**
 181 * _clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1 (lockless)
 182 * @clkdm1: wake this struct clockdomain * up (dependent)
 183 * @clkdm2: when this struct clockdomain * wakes up (source)
 184 *
 185 * When the clockdomain represented by @clkdm2 wakes up, wake up
 186 * @clkdm1. Implemented in hardware on the OMAP, this feature is
 187 * designed to reduce wakeup latency of the dependent clockdomain @clkdm1.
 188 * Returns -EINVAL if presented with invalid clockdomain pointers,
 189 * -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 0 upon
 190 * success.
 191 */
 192static int _clkdm_add_wkdep(struct clockdomain *clkdm1,
 193			    struct clockdomain *clkdm2)
 194{
 195	struct clkdm_dep *cd;
 196	int ret = 0;
 197
 198	if (!clkdm1 || !clkdm2)
 199		return -EINVAL;
 200
 201	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
 202	if (IS_ERR(cd))
 203		ret = PTR_ERR(cd);
 204
 205	if (!arch_clkdm || !arch_clkdm->clkdm_add_wkdep)
 206		ret = -EINVAL;
 207
 208	if (ret) {
 209		pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n",
 210			 clkdm1->name, clkdm2->name);
 211		return ret;
 212	}
 213
 214	cd->wkdep_usecount++;
 215	if (cd->wkdep_usecount == 1) {
 216		pr_debug("clockdomain: hardware will wake up %s when %s wakes up\n",
 217			 clkdm1->name, clkdm2->name);
 218
 219		ret = arch_clkdm->clkdm_add_wkdep(clkdm1, clkdm2);
 220	}
 221
 222	return ret;
 223}
 224
 225/**
 226 * _clkdm_del_wkdep - remove a wakeup dep from clkdm2 to clkdm1 (lockless)
 227 * @clkdm1: wake this struct clockdomain * up (dependent)
 228 * @clkdm2: when this struct clockdomain * wakes up (source)
 229 *
 230 * Remove a wakeup dependency causing @clkdm1 to wake up when @clkdm2
 231 * wakes up.  Returns -EINVAL if presented with invalid clockdomain
 232 * pointers, -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or
 233 * 0 upon success.
 234 */
 235static int _clkdm_del_wkdep(struct clockdomain *clkdm1,
 236			    struct clockdomain *clkdm2)
 237{
 238	struct clkdm_dep *cd;
 239	int ret = 0;
 240
 241	if (!clkdm1 || !clkdm2)
 242		return -EINVAL;
 243
 244	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
 245	if (IS_ERR(cd))
 246		ret = PTR_ERR(cd);
 247
 248	if (!arch_clkdm || !arch_clkdm->clkdm_del_wkdep)
 249		ret = -EINVAL;
 250
 251	if (ret) {
 252		pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n",
 253			 clkdm1->name, clkdm2->name);
 254		return ret;
 255	}
 256
 257	cd->wkdep_usecount--;
 258	if (cd->wkdep_usecount == 0) {
 259		pr_debug("clockdomain: hardware will no longer wake up %s after %s wakes up\n",
 260			 clkdm1->name, clkdm2->name);
 261
 262		ret = arch_clkdm->clkdm_del_wkdep(clkdm1, clkdm2);
 263	}
 264
 265	return ret;
 266}
 267
 268/**
 269 * _clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1 (lockless)
 270 * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
 271 * @clkdm2: when this struct clockdomain * is active (source)
 272 *
 273 * Prevent @clkdm1 from automatically going inactive (and then to
 274 * retention or off) if @clkdm2 is active.  Returns -EINVAL if
 275 * presented with invalid clockdomain pointers or called on a machine
 276 * that does not support software-configurable hardware sleep
 277 * dependencies, -ENOENT if the specified dependency cannot be set in
 278 * hardware, or 0 upon success.
 279 */
 280static int _clkdm_add_sleepdep(struct clockdomain *clkdm1,
 281			       struct clockdomain *clkdm2)
 282{
 283	struct clkdm_dep *cd;
 284	int ret = 0;
 285
 286	if (!clkdm1 || !clkdm2)
 287		return -EINVAL;
 288
 289	cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
 290	if (IS_ERR(cd))
 291		ret = PTR_ERR(cd);
 292
 293	if (!arch_clkdm || !arch_clkdm->clkdm_add_sleepdep)
 294		ret = -EINVAL;
 295
 296	if (ret) {
 297		pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n",
 298			 clkdm1->name, clkdm2->name);
 299		return ret;
 300	}
 301
 302	cd->sleepdep_usecount++;
 303	if (cd->sleepdep_usecount == 1) {
 304		pr_debug("clockdomain: will prevent %s from sleeping if %s is active\n",
 305			 clkdm1->name, clkdm2->name);
 306
 307		ret = arch_clkdm->clkdm_add_sleepdep(clkdm1, clkdm2);
 308	}
 309
 310	return ret;
 311}
 312
 313/**
 314 * _clkdm_del_sleepdep - remove a sleep dep from clkdm2 to clkdm1 (lockless)
 315 * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
 316 * @clkdm2: when this struct clockdomain * is active (source)
 317 *
 318 * Allow @clkdm1 to automatically go inactive (and then to retention or
 319 * off), independent of the activity state of @clkdm2.  Returns -EINVAL
 320 * if presented with invalid clockdomain pointers or called on a machine
 321 * that does not support software-configurable hardware sleep dependencies,
 322 * -ENOENT if the specified dependency cannot be cleared in hardware, or
 323 * 0 upon success.
 324 */
 325static int _clkdm_del_sleepdep(struct clockdomain *clkdm1,
 326			       struct clockdomain *clkdm2)
 327{
 328	struct clkdm_dep *cd;
 329	int ret = 0;
 330
 331	if (!clkdm1 || !clkdm2)
 332		return -EINVAL;
 333
 334	cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
 335	if (IS_ERR(cd))
 336		ret = PTR_ERR(cd);
 337
 338	if (!arch_clkdm || !arch_clkdm->clkdm_del_sleepdep)
 339		ret = -EINVAL;
 340
 341	if (ret) {
 342		pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n",
 343			 clkdm1->name, clkdm2->name);
 344		return ret;
 345	}
 346
 347	cd->sleepdep_usecount--;
 348	if (cd->sleepdep_usecount == 0) {
 349		pr_debug("clockdomain: will no longer prevent %s from sleeping if %s is active\n",
 350			 clkdm1->name, clkdm2->name);
 351
 352		ret = arch_clkdm->clkdm_del_sleepdep(clkdm1, clkdm2);
 353	}
 354
 355	return ret;
 356}
 357
 358/* Public functions */
 359
 360/**
 361 * clkdm_register_platform_funcs - register clockdomain implementation fns
 362 * @co: func pointers for arch specific implementations
 363 *
 364 * Register the list of function pointers used to implement the
 365 * clockdomain functions on different OMAP SoCs.  Should be called
 366 * before any other clkdm_register*() function.  Returns -EINVAL if
 367 * @co is null, -EEXIST if platform functions have already been
 368 * registered, or 0 upon success.
 369 */
 370int clkdm_register_platform_funcs(struct clkdm_ops *co)
 371{
 372	if (!co)
 373		return -EINVAL;
 374
 375	if (arch_clkdm)
 376		return -EEXIST;
 377
 378	arch_clkdm = co;
 379
 380	return 0;
 381};
 382
 383/**
 384 * clkdm_register_clkdms - register SoC clockdomains
 385 * @cs: pointer to an array of struct clockdomain to register
 386 *
 387 * Register the clockdomains available on a particular OMAP SoC.  Must
 388 * be called after clkdm_register_platform_funcs().  May be called
 389 * multiple times.  Returns -EACCES if called before
 390 * clkdm_register_platform_funcs(); -EINVAL if the argument @cs is
 391 * null; or 0 upon success.
 392 */
 393int clkdm_register_clkdms(struct clockdomain **cs)
 394{
 395	struct clockdomain **c = NULL;
 396
 397	if (!arch_clkdm)
 398		return -EACCES;
 399
 400	if (!cs)
 401		return -EINVAL;
 402
 403	for (c = cs; *c; c++)
 404		_clkdm_register(*c);
 405
 406	return 0;
 407}
 408
 409/**
 410 * clkdm_register_autodeps - register autodeps (if required)
 411 * @ia: pointer to a static array of struct clkdm_autodep to register
 412 *
 413 * Register clockdomain "automatic dependencies."  These are
 414 * clockdomain wakeup and sleep dependencies that are automatically
 415 * added whenever the first clock inside a clockdomain is enabled, and
 416 * removed whenever the last clock inside a clockdomain is disabled.
 417 * These are currently only used on OMAP3 devices, and are deprecated,
 418 * since they waste energy.  However, until the OMAP2/3 IP block
 419 * enable/disable sequence can be converted to match the OMAP4
 420 * sequence, they are needed.
 421 *
 422 * Must be called only after all of the SoC clockdomains are
 423 * registered, since the function will resolve autodep clockdomain
 424 * names into clockdomain pointers.
 425 *
 426 * The struct clkdm_autodep @ia array must be static, as this function
 427 * does not copy the array elements.
 428 *
 429 * Returns -EACCES if called before any clockdomains have been
 430 * registered, -EINVAL if called with a null @ia argument, -EEXIST if
 431 * autodeps have already been registered, or 0 upon success.
 432 */
 433int clkdm_register_autodeps(struct clkdm_autodep *ia)
 434{
 435	struct clkdm_autodep *a = NULL;
 436
 437	if (list_empty(&clkdm_list))
 438		return -EACCES;
 439
 440	if (!ia)
 441		return -EINVAL;
 442
 443	if (autodeps)
 444		return -EEXIST;
 445
 446	autodeps = ia;
 447	for (a = autodeps; a->clkdm.ptr; a++)
 448		_autodep_lookup(a);
 449
 450	return 0;
 451}
 452
 453static int cpu_notifier(struct notifier_block *nb, unsigned long cmd, void *v)
 454{
 455	switch (cmd) {
 456	case CPU_CLUSTER_PM_ENTER:
 457		if (enable_off_mode)
 458			clkdm_save_context();
 459		break;
 460	case CPU_CLUSTER_PM_EXIT:
 461		if (enable_off_mode)
 462			clkdm_restore_context();
 463		break;
 464	}
 465
 466	return NOTIFY_OK;
 467}
 468
 469/**
 470 * clkdm_complete_init - set up the clockdomain layer
 471 *
 472 * Put all clockdomains into software-supervised mode; PM code should
 473 * later enable hardware-supervised mode as appropriate.  Must be
 474 * called after clkdm_register_clkdms().  Returns -EACCES if called
 475 * before clkdm_register_clkdms(), or 0 upon success.
 476 */
 477int clkdm_complete_init(void)
 478{
 479	struct clockdomain *clkdm;
 480	static struct notifier_block nb;
 481
 482	if (list_empty(&clkdm_list))
 483		return -EACCES;
 484
 485	list_for_each_entry(clkdm, &clkdm_list, node) {
 486		clkdm_deny_idle(clkdm);
 487
 488		_resolve_clkdm_deps(clkdm, clkdm->wkdep_srcs);
 489		clkdm_clear_all_wkdeps(clkdm);
 490
 491		_resolve_clkdm_deps(clkdm, clkdm->sleepdep_srcs);
 492		clkdm_clear_all_sleepdeps(clkdm);
 493	}
 494
 495	/* Only AM43XX can lose clkdm context during rtc-ddr suspend */
 496	if (soc_is_am43xx()) {
 497		nb.notifier_call = cpu_notifier;
 498		cpu_pm_register_notifier(&nb);
 499	}
 500
 501	return 0;
 502}
 503
 504/**
 505 * clkdm_lookup - look up a clockdomain by name, return a pointer
 506 * @name: name of clockdomain
 507 *
 508 * Find a registered clockdomain by its name @name.  Returns a pointer
 509 * to the struct clockdomain if found, or NULL otherwise.
 510 */
 511struct clockdomain *clkdm_lookup(const char *name)
 512{
 513	struct clockdomain *clkdm, *temp_clkdm;
 514
 515	if (!name)
 516		return NULL;
 517
 518	clkdm = NULL;
 519
 520	list_for_each_entry(temp_clkdm, &clkdm_list, node) {
 521		if (!strcmp(name, temp_clkdm->name)) {
 522			clkdm = temp_clkdm;
 523			break;
 524		}
 525	}
 526
 527	return clkdm;
 528}
 529
 530/**
 531 * clkdm_for_each - call function on each registered clockdomain
 532 * @fn: callback function *
 533 *
 534 * Call the supplied function @fn for each registered clockdomain.
 535 * The callback function @fn can return anything but 0 to bail
 536 * out early from the iterator.  The callback function is called with
 537 * the clkdm_mutex held, so no clockdomain structure manipulation
 538 * functions should be called from the callback, although hardware
 539 * clockdomain control functions are fine.  Returns the last return
 540 * value of the callback function, which should be 0 for success or
 541 * anything else to indicate failure; or -EINVAL if the function pointer
 542 * is null.
 543 */
 544int clkdm_for_each(int (*fn)(struct clockdomain *clkdm, void *user),
 545			void *user)
 546{
 547	struct clockdomain *clkdm;
 548	int ret = 0;
 549
 550	if (!fn)
 551		return -EINVAL;
 552
 553	list_for_each_entry(clkdm, &clkdm_list, node) {
 554		ret = (*fn)(clkdm, user);
 555		if (ret)
 556			break;
 557	}
 558
 559	return ret;
 560}
 561
 562
 563/**
 564 * clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in
 565 * @clkdm: struct clockdomain *
 566 *
 567 * Return a pointer to the struct powerdomain that the specified clockdomain
 568 * @clkdm exists in, or returns NULL if @clkdm is NULL.
 569 */
 570struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
 571{
 572	if (!clkdm)
 573		return NULL;
 574
 575	return clkdm->pwrdm.ptr;
 576}
 577
 578
 579/* Hardware clockdomain control */
 580
 581/**
 582 * clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1
 583 * @clkdm1: wake this struct clockdomain * up (dependent)
 584 * @clkdm2: when this struct clockdomain * wakes up (source)
 585 *
 586 * When the clockdomain represented by @clkdm2 wakes up, wake up
 587 * @clkdm1. Implemented in hardware on the OMAP, this feature is
 588 * designed to reduce wakeup latency of the dependent clockdomain @clkdm1.
 589 * Returns -EINVAL if presented with invalid clockdomain pointers,
 590 * -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 0 upon
 591 * success.
 592 */
 593int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 594{
 595	struct clkdm_dep *cd;
 596	int ret;
 597
 598	if (!clkdm1 || !clkdm2)
 599		return -EINVAL;
 600
 601	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
 602	if (IS_ERR(cd))
 603		return PTR_ERR(cd);
 604
 605	pwrdm_lock(cd->clkdm->pwrdm.ptr);
 606	ret = _clkdm_add_wkdep(clkdm1, clkdm2);
 607	pwrdm_unlock(cd->clkdm->pwrdm.ptr);
 608
 609	return ret;
 610}
 611
 612/**
 613 * clkdm_del_wkdep - remove a wakeup dependency from clkdm2 to clkdm1
 614 * @clkdm1: wake this struct clockdomain * up (dependent)
 615 * @clkdm2: when this struct clockdomain * wakes up (source)
 616 *
 617 * Remove a wakeup dependency causing @clkdm1 to wake up when @clkdm2
 618 * wakes up.  Returns -EINVAL if presented with invalid clockdomain
 619 * pointers, -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or
 620 * 0 upon success.
 621 */
 622int clkdm_del_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 623{
 624	struct clkdm_dep *cd;
 625	int ret;
 626
 627	if (!clkdm1 || !clkdm2)
 628		return -EINVAL;
 629
 630	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
 631	if (IS_ERR(cd))
 632		return PTR_ERR(cd);
 633
 634	pwrdm_lock(cd->clkdm->pwrdm.ptr);
 635	ret = _clkdm_del_wkdep(clkdm1, clkdm2);
 636	pwrdm_unlock(cd->clkdm->pwrdm.ptr);
 637
 638	return ret;
 639}
 640
 641/**
 642 * clkdm_read_wkdep - read wakeup dependency state from clkdm2 to clkdm1
 643 * @clkdm1: wake this struct clockdomain * up (dependent)
 644 * @clkdm2: when this struct clockdomain * wakes up (source)
 645 *
 646 * Return 1 if a hardware wakeup dependency exists wherein @clkdm1 will be
 647 * awoken when @clkdm2 wakes up; 0 if dependency is not set; -EINVAL
 648 * if either clockdomain pointer is invalid; or -ENOENT if the hardware
 649 * is incapable.
 650 *
 651 * REVISIT: Currently this function only represents software-controllable
 652 * wakeup dependencies.  Wakeup dependencies fixed in hardware are not
 653 * yet handled here.
 654 */
 655int clkdm_read_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 656{
 657	struct clkdm_dep *cd;
 658	int ret = 0;
 659
 660	if (!clkdm1 || !clkdm2)
 661		return -EINVAL;
 662
 663	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
 664	if (IS_ERR(cd))
 665		ret = PTR_ERR(cd);
 666
 667	if (!arch_clkdm || !arch_clkdm->clkdm_read_wkdep)
 668		ret = -EINVAL;
 669
 670	if (ret) {
 671		pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n",
 672			 clkdm1->name, clkdm2->name);
 673		return ret;
 674	}
 675
 676	/* XXX It's faster to return the wkdep_usecount */
 677	return arch_clkdm->clkdm_read_wkdep(clkdm1, clkdm2);
 678}
 679
 680/**
 681 * clkdm_clear_all_wkdeps - remove all wakeup dependencies from target clkdm
 682 * @clkdm: struct clockdomain * to remove all wakeup dependencies from
 683 *
 684 * Remove all inter-clockdomain wakeup dependencies that could cause
 685 * @clkdm to wake.  Intended to be used during boot to initialize the
 686 * PRCM to a known state, after all clockdomains are put into swsup idle
 687 * and woken up.  Returns -EINVAL if @clkdm pointer is invalid, or
 688 * 0 upon success.
 689 */
 690int clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
 691{
 692	if (!clkdm)
 693		return -EINVAL;
 694
 695	if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_wkdeps)
 696		return -EINVAL;
 697
 698	return arch_clkdm->clkdm_clear_all_wkdeps(clkdm);
 699}
 700
 701/**
 702 * clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1
 703 * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
 704 * @clkdm2: when this struct clockdomain * is active (source)
 705 *
 706 * Prevent @clkdm1 from automatically going inactive (and then to
 707 * retention or off) if @clkdm2 is active.  Returns -EINVAL if
 708 * presented with invalid clockdomain pointers or called on a machine
 709 * that does not support software-configurable hardware sleep
 710 * dependencies, -ENOENT if the specified dependency cannot be set in
 711 * hardware, or 0 upon success.
 712 */
 713int clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 714{
 715	struct clkdm_dep *cd;
 716	int ret;
 717
 718	if (!clkdm1 || !clkdm2)
 719		return -EINVAL;
 720
 721	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
 722	if (IS_ERR(cd))
 723		return PTR_ERR(cd);
 724
 725	pwrdm_lock(cd->clkdm->pwrdm.ptr);
 726	ret = _clkdm_add_sleepdep(clkdm1, clkdm2);
 727	pwrdm_unlock(cd->clkdm->pwrdm.ptr);
 728
 729	return ret;
 730}
 731
 732/**
 733 * clkdm_del_sleepdep - remove a sleep dependency from clkdm2 to clkdm1
 734 * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
 735 * @clkdm2: when this struct clockdomain * is active (source)
 736 *
 737 * Allow @clkdm1 to automatically go inactive (and then to retention or
 738 * off), independent of the activity state of @clkdm2.  Returns -EINVAL
 739 * if presented with invalid clockdomain pointers or called on a machine
 740 * that does not support software-configurable hardware sleep dependencies,
 741 * -ENOENT if the specified dependency cannot be cleared in hardware, or
 742 * 0 upon success.
 743 */
 744int clkdm_del_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 745{
 746	struct clkdm_dep *cd;
 747	int ret;
 748
 749	if (!clkdm1 || !clkdm2)
 750		return -EINVAL;
 751
 752	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
 753	if (IS_ERR(cd))
 754		return PTR_ERR(cd);
 755
 756	pwrdm_lock(cd->clkdm->pwrdm.ptr);
 757	ret = _clkdm_del_sleepdep(clkdm1, clkdm2);
 758	pwrdm_unlock(cd->clkdm->pwrdm.ptr);
 759
 760	return ret;
 761}
 762
 763/**
 764 * clkdm_read_sleepdep - read sleep dependency state from clkdm2 to clkdm1
 765 * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
 766 * @clkdm2: when this struct clockdomain * is active (source)
 767 *
 768 * Return 1 if a hardware sleep dependency exists wherein @clkdm1 will
 769 * not be allowed to automatically go inactive if @clkdm2 is active;
 770 * 0 if @clkdm1's automatic power state inactivity transition is independent
 771 * of @clkdm2's; -EINVAL if either clockdomain pointer is invalid or called
 772 * on a machine that does not support software-configurable hardware sleep
 773 * dependencies; or -ENOENT if the hardware is incapable.
 774 *
 775 * REVISIT: Currently this function only represents software-controllable
 776 * sleep dependencies.	Sleep dependencies fixed in hardware are not
 777 * yet handled here.
 778 */
 779int clkdm_read_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 780{
 781	struct clkdm_dep *cd;
 782	int ret = 0;
 783
 784	if (!clkdm1 || !clkdm2)
 785		return -EINVAL;
 786
 787	cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
 788	if (IS_ERR(cd))
 789		ret = PTR_ERR(cd);
 790
 791	if (!arch_clkdm || !arch_clkdm->clkdm_read_sleepdep)
 792		ret = -EINVAL;
 793
 794	if (ret) {
 795		pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n",
 796			 clkdm1->name, clkdm2->name);
 797		return ret;
 798	}
 799
 800	/* XXX It's faster to return the sleepdep_usecount */
 801	return arch_clkdm->clkdm_read_sleepdep(clkdm1, clkdm2);
 802}
 803
 804/**
 805 * clkdm_clear_all_sleepdeps - remove all sleep dependencies from target clkdm
 806 * @clkdm: struct clockdomain * to remove all sleep dependencies from
 807 *
 808 * Remove all inter-clockdomain sleep dependencies that could prevent
 809 * @clkdm from idling.  Intended to be used during boot to initialize the
 810 * PRCM to a known state, after all clockdomains are put into swsup idle
 811 * and woken up.  Returns -EINVAL if @clkdm pointer is invalid, or
 812 * 0 upon success.
 813 */
 814int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm)
 815{
 816	if (!clkdm)
 817		return -EINVAL;
 818
 819	if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_sleepdeps)
 820		return -EINVAL;
 821
 822	return arch_clkdm->clkdm_clear_all_sleepdeps(clkdm);
 823}
 824
 825/**
 826 * clkdm_sleep_nolock - force clockdomain sleep transition (lockless)
 827 * @clkdm: struct clockdomain *
 828 *
 829 * Instruct the CM to force a sleep transition on the specified
 830 * clockdomain @clkdm.  Only for use by the powerdomain code.  Returns
 831 * -EINVAL if @clkdm is NULL or if clockdomain does not support
 832 * software-initiated sleep; 0 upon success.
 833 */
 834static int clkdm_sleep_nolock(struct clockdomain *clkdm)
 835{
 836	int ret;
 837
 838	if (!clkdm)
 839		return -EINVAL;
 840
 841	if (!(clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) {
 842		pr_debug("clockdomain: %s does not support forcing sleep via software\n",
 843			 clkdm->name);
 844		return -EINVAL;
 845	}
 846
 847	if (!arch_clkdm || !arch_clkdm->clkdm_sleep)
 848		return -EINVAL;
 849
 850	pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name);
 851
 852	clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
 853	ret = arch_clkdm->clkdm_sleep(clkdm);
 854	ret |= pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
 855
 856	return ret;
 857}
 858
 859/**
 860 * clkdm_sleep - force clockdomain sleep transition
 861 * @clkdm: struct clockdomain *
 862 *
 863 * Instruct the CM to force a sleep transition on the specified
 864 * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if
 865 * clockdomain does not support software-initiated sleep; 0 upon
 866 * success.
 867 */
 868int clkdm_sleep(struct clockdomain *clkdm)
 869{
 870	int ret;
 871
 872	pwrdm_lock(clkdm->pwrdm.ptr);
 873	ret = clkdm_sleep_nolock(clkdm);
 874	pwrdm_unlock(clkdm->pwrdm.ptr);
 875
 876	return ret;
 877}
 878
 879/**
 880 * clkdm_wakeup_nolock - force clockdomain wakeup transition (lockless)
 881 * @clkdm: struct clockdomain *
 882 *
 883 * Instruct the CM to force a wakeup transition on the specified
 884 * clockdomain @clkdm.  Only for use by the powerdomain code.  Returns
 885 * -EINVAL if @clkdm is NULL or if the clockdomain does not support
 886 * software-controlled wakeup; 0 upon success.
 887 */
 888static int clkdm_wakeup_nolock(struct clockdomain *clkdm)
 889{
 890	int ret;
 891
 892	if (!clkdm)
 893		return -EINVAL;
 894
 895	if (!(clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)) {
 896		pr_debug("clockdomain: %s does not support forcing wakeup via software\n",
 897			 clkdm->name);
 898		return -EINVAL;
 899	}
 900
 901	if (!arch_clkdm || !arch_clkdm->clkdm_wakeup)
 902		return -EINVAL;
 903
 904	pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name);
 905
 906	clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
 907	ret = arch_clkdm->clkdm_wakeup(clkdm);
 908	ret |= pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
 909
 910	return ret;
 911}
 912
 913/**
 914 * clkdm_wakeup - force clockdomain wakeup transition
 915 * @clkdm: struct clockdomain *
 916 *
 917 * Instruct the CM to force a wakeup transition on the specified
 918 * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if the
 919 * clockdomain does not support software-controlled wakeup; 0 upon
 920 * success.
 921 */
 922int clkdm_wakeup(struct clockdomain *clkdm)
 923{
 924	int ret;
 925
 926	pwrdm_lock(clkdm->pwrdm.ptr);
 927	ret = clkdm_wakeup_nolock(clkdm);
 928	pwrdm_unlock(clkdm->pwrdm.ptr);
 929
 930	return ret;
 931}
 932
 933/**
 934 * clkdm_allow_idle_nolock - enable hwsup idle transitions for clkdm
 935 * @clkdm: struct clockdomain *
 936 *
 937 * Allow the hardware to automatically switch the clockdomain @clkdm
 938 * into active or idle states, as needed by downstream clocks.  If the
 939 * clockdomain has any downstream clocks enabled in the clock
 940 * framework, wkdep/sleepdep autodependencies are added; this is so
 941 * device drivers can read and write to the device.  Only for use by
 942 * the powerdomain code.  No return value.
 943 */
 944void clkdm_allow_idle_nolock(struct clockdomain *clkdm)
 945{
 946	if (!clkdm)
 947		return;
 948
 949	if (!WARN_ON(!clkdm->forcewake_count))
 950		clkdm->forcewake_count--;
 951
 952	if (clkdm->forcewake_count)
 953		return;
 954
 955	if (!clkdm->usecount && (clkdm->flags & CLKDM_CAN_FORCE_SLEEP))
 956		clkdm_sleep_nolock(clkdm);
 957
 958	if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO))
 959		return;
 960
 961	if (clkdm->flags & CLKDM_MISSING_IDLE_REPORTING)
 962		return;
 963
 964	if (!arch_clkdm || !arch_clkdm->clkdm_allow_idle)
 965		return;
 966
 967	pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
 968		 clkdm->name);
 969
 970	clkdm->_flags |= _CLKDM_FLAG_HWSUP_ENABLED;
 971	arch_clkdm->clkdm_allow_idle(clkdm);
 972	pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
 973}
 974
 975/**
 976 * clkdm_allow_idle - enable hwsup idle transitions for clkdm
 977 * @clkdm: struct clockdomain *
 978 *
 979 * Allow the hardware to automatically switch the clockdomain @clkdm into
 980 * active or idle states, as needed by downstream clocks.  If the
 981 * clockdomain has any downstream clocks enabled in the clock
 982 * framework, wkdep/sleepdep autodependencies are added; this is so
 983 * device drivers can read and write to the device.  No return value.
 984 */
 985void clkdm_allow_idle(struct clockdomain *clkdm)
 986{
 987	pwrdm_lock(clkdm->pwrdm.ptr);
 988	clkdm_allow_idle_nolock(clkdm);
 989	pwrdm_unlock(clkdm->pwrdm.ptr);
 990}
 991
 992/**
 993 * clkdm_deny_idle_nolock - disable hwsup idle transitions for clkdm
 994 * @clkdm: struct clockdomain *
 995 *
 996 * Prevent the hardware from automatically switching the clockdomain
 997 * @clkdm into inactive or idle states.  If the clockdomain has
 998 * downstream clocks enabled in the clock framework, wkdep/sleepdep
 999 * autodependencies are removed.  Only for use by the powerdomain
1000 * code.  No return value.
1001 */
1002void clkdm_deny_idle_nolock(struct clockdomain *clkdm)
1003{
1004	if (!clkdm)
1005		return;
1006
1007	if (clkdm->forcewake_count++)
1008		return;
1009
1010	if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
1011		clkdm_wakeup_nolock(clkdm);
1012
1013	if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO))
1014		return;
1015
1016	if (clkdm->flags & CLKDM_MISSING_IDLE_REPORTING)
1017		return;
1018
1019	if (!arch_clkdm || !arch_clkdm->clkdm_deny_idle)
1020		return;
1021
1022	pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
1023		 clkdm->name);
1024
1025	clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
1026	arch_clkdm->clkdm_deny_idle(clkdm);
1027	pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
1028}
1029
1030/**
1031 * clkdm_deny_idle - disable hwsup idle transitions for clkdm
1032 * @clkdm: struct clockdomain *
1033 *
1034 * Prevent the hardware from automatically switching the clockdomain
1035 * @clkdm into inactive or idle states.  If the clockdomain has
1036 * downstream clocks enabled in the clock framework, wkdep/sleepdep
1037 * autodependencies are removed.  No return value.
1038 */
1039void clkdm_deny_idle(struct clockdomain *clkdm)
1040{
1041	pwrdm_lock(clkdm->pwrdm.ptr);
1042	clkdm_deny_idle_nolock(clkdm);
1043	pwrdm_unlock(clkdm->pwrdm.ptr);
1044}
1045
1046/* Public autodep handling functions (deprecated) */
1047
1048/**
1049 * clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
1050 * @clkdm: struct clockdomain *
1051 *
1052 * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm'
1053 * in hardware-supervised mode.  Meant to be called from clock framework
1054 * when a clock inside clockdomain 'clkdm' is enabled.	No return value.
1055 *
1056 * XXX autodeps are deprecated and should be removed at the earliest
1057 * opportunity
1058 */
1059void clkdm_add_autodeps(struct clockdomain *clkdm)
1060{
1061	struct clkdm_autodep *autodep;
1062
1063	if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
1064		return;
1065
1066	for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
1067		if (IS_ERR(autodep->clkdm.ptr))
1068			continue;
1069
1070		pr_debug("clockdomain: %s: adding %s sleepdep/wkdep\n",
1071			 clkdm->name, autodep->clkdm.ptr->name);
1072
1073		_clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr);
1074		_clkdm_add_wkdep(clkdm, autodep->clkdm.ptr);
1075	}
1076}
1077
1078/**
1079 * clkdm_del_autodeps - remove auto sleepdeps/wkdeps from clkdm
1080 * @clkdm: struct clockdomain *
1081 *
1082 * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm'
1083 * in hardware-supervised mode.  Meant to be called from clock framework
1084 * when a clock inside clockdomain 'clkdm' is disabled.  No return value.
1085 *
1086 * XXX autodeps are deprecated and should be removed at the earliest
1087 * opportunity
1088 */
1089void clkdm_del_autodeps(struct clockdomain *clkdm)
1090{
1091	struct clkdm_autodep *autodep;
1092
1093	if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
1094		return;
1095
1096	for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
1097		if (IS_ERR(autodep->clkdm.ptr))
1098			continue;
1099
1100		pr_debug("clockdomain: %s: removing %s sleepdep/wkdep\n",
1101			 clkdm->name, autodep->clkdm.ptr->name);
1102
1103		_clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr);
1104		_clkdm_del_wkdep(clkdm, autodep->clkdm.ptr);
1105	}
1106}
1107
1108/* Clockdomain-to-clock/hwmod framework interface code */
1109
1110/**
1111 * clkdm_clk_enable - add an enabled downstream clock to this clkdm
1112 * @clkdm: struct clockdomain *
1113 * @unused: struct clk * of the enabled downstream clock
1114 *
1115 * Increment the usecount of the clockdomain @clkdm and ensure that it
1116 * is awake before @clk is enabled.  Intended to be called by
1117 * clk_enable() code.  If the clockdomain is in software-supervised
1118 * idle mode, force the clockdomain to wake.  If the clockdomain is in
1119 * hardware-supervised idle mode, add clkdm-pwrdm autodependencies, to
1120 * ensure that devices in the clockdomain can be read from/written to
1121 * by on-chip processors.  Returns -EINVAL if passed null pointers;
1122 * returns 0 upon success or if the clockdomain is in hwsup idle mode.
1123 */
1124int clkdm_clk_enable(struct clockdomain *clkdm, struct clk *unused)
1125{
1126	if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_enable)
1127		return -EINVAL;
1128
1129	pwrdm_lock(clkdm->pwrdm.ptr);
1130
1131	/*
1132	 * For arch's with no autodeps, clkcm_clk_enable
1133	 * should be called for every clock instance or hwmod that is
1134	 * enabled, so the clkdm can be force woken up.
1135	 */
1136	clkdm->usecount++;
1137	if (clkdm->usecount > 1 && autodeps) {
1138		pwrdm_unlock(clkdm->pwrdm.ptr);
1139		return 0;
1140	}
1141
1142	arch_clkdm->clkdm_clk_enable(clkdm);
1143	pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
1144	pwrdm_unlock(clkdm->pwrdm.ptr);
1145
1146	pr_debug("clockdomain: %s: enabled\n", clkdm->name);
1147
1148	return 0;
1149}
1150
1151/**
1152 * clkdm_clk_disable - remove an enabled downstream clock from this clkdm
1153 * @clkdm: struct clockdomain *
1154 * @clk: struct clk * of the disabled downstream clock
1155 *
1156 * Decrement the usecount of this clockdomain @clkdm when @clk is
1157 * disabled.  Intended to be called by clk_disable() code.  If the
1158 * clockdomain usecount goes to 0, put the clockdomain to sleep
1159 * (software-supervised mode) or remove the clkdm autodependencies
1160 * (hardware-supervised mode).  Returns -EINVAL if passed null
1161 * pointers; -ERANGE if the @clkdm usecount underflows; or returns 0
1162 * upon success or if the clockdomain is in hwsup idle mode.
1163 */
1164int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
1165{
1166	if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_disable)
1167		return -EINVAL;
1168
1169	pwrdm_lock(clkdm->pwrdm.ptr);
1170
1171	/* corner case: disabling unused clocks */
1172	if (clk && (__clk_get_enable_count(clk) == 0) && clkdm->usecount == 0)
1173		goto ccd_exit;
1174
1175	if (clkdm->usecount == 0) {
1176		pwrdm_unlock(clkdm->pwrdm.ptr);
1177		WARN_ON(1); /* underflow */
1178		return -ERANGE;
1179	}
1180
1181	clkdm->usecount--;
1182	if (clkdm->usecount > 0) {
1183		pwrdm_unlock(clkdm->pwrdm.ptr);
1184		return 0;
1185	}
1186
1187	arch_clkdm->clkdm_clk_disable(clkdm);
1188	pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
1189
1190	pr_debug("clockdomain: %s: disabled\n", clkdm->name);
1191
1192ccd_exit:
1193	pwrdm_unlock(clkdm->pwrdm.ptr);
1194
1195	return 0;
1196}
1197
1198/**
1199 * clkdm_hwmod_enable - add an enabled downstream hwmod to this clkdm
1200 * @clkdm: struct clockdomain *
1201 * @oh: struct omap_hwmod * of the enabled downstream hwmod
1202 *
1203 * Increment the usecount of the clockdomain @clkdm and ensure that it
1204 * is awake before @oh is enabled. Intended to be called by
1205 * module_enable() code.
1206 * If the clockdomain is in software-supervised idle mode, force the
1207 * clockdomain to wake.  If the clockdomain is in hardware-supervised idle
1208 * mode, add clkdm-pwrdm autodependencies, to ensure that devices in the
1209 * clockdomain can be read from/written to by on-chip processors.
1210 * Returns -EINVAL if passed null pointers;
1211 * returns 0 upon success or if the clockdomain is in hwsup idle mode.
1212 */
1213int clkdm_hwmod_enable(struct clockdomain *clkdm, struct omap_hwmod *oh)
1214{
1215	/* The clkdm attribute does not exist yet prior OMAP4 */
1216	if (cpu_is_omap24xx() || cpu_is_omap34xx())
1217		return 0;
1218
1219	/*
1220	 * XXX Rewrite this code to maintain a list of enabled
1221	 * downstream hwmods for debugging purposes?
1222	 */
1223
1224	if (!oh)
1225		return -EINVAL;
1226
1227	return clkdm_clk_enable(clkdm, NULL);
1228}
1229
1230/**
1231 * clkdm_hwmod_disable - remove an enabled downstream hwmod from this clkdm
1232 * @clkdm: struct clockdomain *
1233 * @oh: struct omap_hwmod * of the disabled downstream hwmod
1234 *
1235 * Decrement the usecount of this clockdomain @clkdm when @oh is
1236 * disabled. Intended to be called by module_disable() code.
1237 * If the clockdomain usecount goes to 0, put the clockdomain to sleep
1238 * (software-supervised mode) or remove the clkdm autodependencies
1239 * (hardware-supervised mode).
1240 * Returns -EINVAL if passed null pointers; -ERANGE if the @clkdm usecount
1241 * underflows; or returns 0 upon success or if the clockdomain is in hwsup
1242 * idle mode.
1243 */
1244int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh)
1245{
1246	/* The clkdm attribute does not exist yet prior OMAP4 */
1247	if (cpu_is_omap24xx() || cpu_is_omap34xx())
1248		return 0;
1249
1250	if (!oh)
1251		return -EINVAL;
1252
1253	return clkdm_clk_disable(clkdm, NULL);
1254}
1255
1256/**
1257 * _clkdm_save_context - save the context for the control of this clkdm
1258 *
1259 * Due to a suspend or hibernation operation, the state of the registers
1260 * controlling this clkdm will be lost, save their context.
1261 */
1262static int _clkdm_save_context(struct clockdomain *clkdm, void *unused)
1263{
1264	if (!arch_clkdm || !arch_clkdm->clkdm_save_context)
1265		return -EINVAL;
1266
1267	return arch_clkdm->clkdm_save_context(clkdm);
1268}
1269
1270/**
1271 * _clkdm_restore_context - restore context for control of this clkdm
1272 *
1273 * Restore the register values for this clockdomain.
1274 */
1275static int _clkdm_restore_context(struct clockdomain *clkdm, void *unused)
1276{
1277	if (!arch_clkdm || !arch_clkdm->clkdm_restore_context)
1278		return -EINVAL;
1279
1280	return arch_clkdm->clkdm_restore_context(clkdm);
1281}
1282
1283/**
1284 * clkdm_save_context - Saves the context for each registered clkdm
1285 *
1286 * Save the context for each registered clockdomain.
1287 */
1288void clkdm_save_context(void)
1289{
1290	clkdm_for_each(_clkdm_save_context, NULL);
1291}
1292
1293/**
1294 * clkdm_restore_context - Restores the context for each registered clkdm
1295 *
1296 * Restore the context for each registered clockdomain.
1297 */
1298void clkdm_restore_context(void)
1299{
1300	clkdm_for_each(_clkdm_restore_context, NULL);
1301}