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