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 #include <linux/clk-provider.h> 26 27 #include <linux/io.h> 28 29 #include <linux/bitops.h> 30 31 #include "soc.h" 32 #include "clock.h" 33 #include "clockdomain.h" 34 35 /* clkdm_list contains all registered struct clockdomains */ 36 static LIST_HEAD(clkdm_list); 37 38 /* array of clockdomain deps to be added/removed when clkdm in hwsup mode */ 39 static struct clkdm_autodep *autodeps; 40 41 static struct clkdm_ops *arch_clkdm; 42 43 /* Private functions */ 44 45 static struct clockdomain *_clkdm_lookup(const char *name) 46 { 47 struct clockdomain *clkdm, *temp_clkdm; 48 49 if (!name) 50 return NULL; 51 52 clkdm = NULL; 53 54 list_for_each_entry(temp_clkdm, &clkdm_list, node) { 55 if (!strcmp(name, temp_clkdm->name)) { 56 clkdm = temp_clkdm; 57 break; 58 } 59 } 60 61 return clkdm; 62 } 63 64 /** 65 * _clkdm_register - register a clockdomain 66 * @clkdm: struct clockdomain * to register 67 * 68 * Adds a clockdomain to the internal clockdomain list. 69 * Returns -EINVAL if given a null pointer, -EEXIST if a clockdomain is 70 * already registered by the provided name, or 0 upon success. 71 */ 72 static int _clkdm_register(struct clockdomain *clkdm) 73 { 74 struct powerdomain *pwrdm; 75 76 if (!clkdm || !clkdm->name) 77 return -EINVAL; 78 79 pwrdm = pwrdm_lookup(clkdm->pwrdm.name); 80 if (!pwrdm) { 81 pr_err("clockdomain: %s: powerdomain %s does not exist\n", 82 clkdm->name, clkdm->pwrdm.name); 83 return -EINVAL; 84 } 85 clkdm->pwrdm.ptr = pwrdm; 86 87 /* Verify that the clockdomain is not already registered */ 88 if (_clkdm_lookup(clkdm->name)) 89 return -EEXIST; 90 91 list_add(&clkdm->node, &clkdm_list); 92 93 pwrdm_add_clkdm(pwrdm, clkdm); 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 */ 101 static 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 */ 139 static 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 * _resolve_clkdm_deps() - resolve clkdm_names in @clkdm_deps to clkdms 157 * @clkdm: clockdomain that we are resolving dependencies for 158 * @clkdm_deps: ptr to array of struct clkdm_deps to resolve 159 * 160 * Iterates through @clkdm_deps, looking up the struct clockdomain named by 161 * clkdm_name and storing the clockdomain pointer in the struct clkdm_dep. 162 * No return value. 163 */ 164 static void _resolve_clkdm_deps(struct clockdomain *clkdm, 165 struct clkdm_dep *clkdm_deps) 166 { 167 struct clkdm_dep *cd; 168 169 for (cd = clkdm_deps; cd && cd->clkdm_name; cd++) { 170 if (cd->clkdm) 171 continue; 172 cd->clkdm = _clkdm_lookup(cd->clkdm_name); 173 174 WARN(!cd->clkdm, "clockdomain: %s: could not find clkdm %s while resolving dependencies - should never happen", 175 clkdm->name, cd->clkdm_name); 176 } 177 } 178 179 /** 180 * _clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1 (lockless) 181 * @clkdm1: wake this struct clockdomain * up (dependent) 182 * @clkdm2: when this struct clockdomain * wakes up (source) 183 * 184 * When the clockdomain represented by @clkdm2 wakes up, wake up 185 * @clkdm1. Implemented in hardware on the OMAP, this feature is 186 * designed to reduce wakeup latency of the dependent clockdomain @clkdm1. 187 * Returns -EINVAL if presented with invalid clockdomain pointers, 188 * -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 0 upon 189 * success. 190 */ 191 static int _clkdm_add_wkdep(struct clockdomain *clkdm1, 192 struct clockdomain *clkdm2) 193 { 194 struct clkdm_dep *cd; 195 int ret = 0; 196 197 if (!clkdm1 || !clkdm2) 198 return -EINVAL; 199 200 cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs); 201 if (IS_ERR(cd)) 202 ret = PTR_ERR(cd); 203 204 if (!arch_clkdm || !arch_clkdm->clkdm_add_wkdep) 205 ret = -EINVAL; 206 207 if (ret) { 208 pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n", 209 clkdm1->name, clkdm2->name); 210 return ret; 211 } 212 213 cd->wkdep_usecount++; 214 if (cd->wkdep_usecount == 1) { 215 pr_debug("clockdomain: hardware will wake up %s when %s wakes up\n", 216 clkdm1->name, clkdm2->name); 217 218 ret = arch_clkdm->clkdm_add_wkdep(clkdm1, clkdm2); 219 } 220 221 return ret; 222 } 223 224 /** 225 * _clkdm_del_wkdep - remove a wakeup dep from clkdm2 to clkdm1 (lockless) 226 * @clkdm1: wake this struct clockdomain * up (dependent) 227 * @clkdm2: when this struct clockdomain * wakes up (source) 228 * 229 * Remove a wakeup dependency causing @clkdm1 to wake up when @clkdm2 230 * wakes up. Returns -EINVAL if presented with invalid clockdomain 231 * pointers, -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 232 * 0 upon success. 233 */ 234 static int _clkdm_del_wkdep(struct clockdomain *clkdm1, 235 struct clockdomain *clkdm2) 236 { 237 struct clkdm_dep *cd; 238 int ret = 0; 239 240 if (!clkdm1 || !clkdm2) 241 return -EINVAL; 242 243 cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs); 244 if (IS_ERR(cd)) 245 ret = PTR_ERR(cd); 246 247 if (!arch_clkdm || !arch_clkdm->clkdm_del_wkdep) 248 ret = -EINVAL; 249 250 if (ret) { 251 pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n", 252 clkdm1->name, clkdm2->name); 253 return ret; 254 } 255 256 cd->wkdep_usecount--; 257 if (cd->wkdep_usecount == 0) { 258 pr_debug("clockdomain: hardware will no longer wake up %s after %s wakes up\n", 259 clkdm1->name, clkdm2->name); 260 261 ret = arch_clkdm->clkdm_del_wkdep(clkdm1, clkdm2); 262 } 263 264 return ret; 265 } 266 267 /** 268 * _clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1 (lockless) 269 * @clkdm1: prevent this struct clockdomain * from sleeping (dependent) 270 * @clkdm2: when this struct clockdomain * is active (source) 271 * 272 * Prevent @clkdm1 from automatically going inactive (and then to 273 * retention or off) if @clkdm2 is active. Returns -EINVAL if 274 * presented with invalid clockdomain pointers or called on a machine 275 * that does not support software-configurable hardware sleep 276 * dependencies, -ENOENT if the specified dependency cannot be set in 277 * hardware, or 0 upon success. 278 */ 279 static int _clkdm_add_sleepdep(struct clockdomain *clkdm1, 280 struct clockdomain *clkdm2) 281 { 282 struct clkdm_dep *cd; 283 int ret = 0; 284 285 if (!clkdm1 || !clkdm2) 286 return -EINVAL; 287 288 cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs); 289 if (IS_ERR(cd)) 290 ret = PTR_ERR(cd); 291 292 if (!arch_clkdm || !arch_clkdm->clkdm_add_sleepdep) 293 ret = -EINVAL; 294 295 if (ret) { 296 pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n", 297 clkdm1->name, clkdm2->name); 298 return ret; 299 } 300 301 cd->sleepdep_usecount++; 302 if (cd->sleepdep_usecount == 1) { 303 pr_debug("clockdomain: will prevent %s from sleeping if %s is active\n", 304 clkdm1->name, clkdm2->name); 305 306 ret = arch_clkdm->clkdm_add_sleepdep(clkdm1, clkdm2); 307 } 308 309 return ret; 310 } 311 312 /** 313 * _clkdm_del_sleepdep - remove a sleep dep from clkdm2 to clkdm1 (lockless) 314 * @clkdm1: prevent this struct clockdomain * from sleeping (dependent) 315 * @clkdm2: when this struct clockdomain * is active (source) 316 * 317 * Allow @clkdm1 to automatically go inactive (and then to retention or 318 * off), independent of the activity state of @clkdm2. Returns -EINVAL 319 * if presented with invalid clockdomain pointers or called on a machine 320 * that does not support software-configurable hardware sleep dependencies, 321 * -ENOENT if the specified dependency cannot be cleared in hardware, or 322 * 0 upon success. 323 */ 324 static int _clkdm_del_sleepdep(struct clockdomain *clkdm1, 325 struct clockdomain *clkdm2) 326 { 327 struct clkdm_dep *cd; 328 int ret = 0; 329 330 if (!clkdm1 || !clkdm2) 331 return -EINVAL; 332 333 cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs); 334 if (IS_ERR(cd)) 335 ret = PTR_ERR(cd); 336 337 if (!arch_clkdm || !arch_clkdm->clkdm_del_sleepdep) 338 ret = -EINVAL; 339 340 if (ret) { 341 pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n", 342 clkdm1->name, clkdm2->name); 343 return ret; 344 } 345 346 cd->sleepdep_usecount--; 347 if (cd->sleepdep_usecount == 0) { 348 pr_debug("clockdomain: will no longer prevent %s from sleeping if %s is active\n", 349 clkdm1->name, clkdm2->name); 350 351 ret = arch_clkdm->clkdm_del_sleepdep(clkdm1, clkdm2); 352 } 353 354 return ret; 355 } 356 357 /* Public functions */ 358 359 /** 360 * clkdm_register_platform_funcs - register clockdomain implementation fns 361 * @co: func pointers for arch specific implementations 362 * 363 * Register the list of function pointers used to implement the 364 * clockdomain functions on different OMAP SoCs. Should be called 365 * before any other clkdm_register*() function. Returns -EINVAL if 366 * @co is null, -EEXIST if platform functions have already been 367 * registered, or 0 upon success. 368 */ 369 int clkdm_register_platform_funcs(struct clkdm_ops *co) 370 { 371 if (!co) 372 return -EINVAL; 373 374 if (arch_clkdm) 375 return -EEXIST; 376 377 arch_clkdm = co; 378 379 return 0; 380 }; 381 382 /** 383 * clkdm_register_clkdms - register SoC clockdomains 384 * @cs: pointer to an array of struct clockdomain to register 385 * 386 * Register the clockdomains available on a particular OMAP SoC. Must 387 * be called after clkdm_register_platform_funcs(). May be called 388 * multiple times. Returns -EACCES if called before 389 * clkdm_register_platform_funcs(); -EINVAL if the argument @cs is 390 * null; or 0 upon success. 391 */ 392 int clkdm_register_clkdms(struct clockdomain **cs) 393 { 394 struct clockdomain **c = NULL; 395 396 if (!arch_clkdm) 397 return -EACCES; 398 399 if (!cs) 400 return -EINVAL; 401 402 for (c = cs; *c; c++) 403 _clkdm_register(*c); 404 405 return 0; 406 } 407 408 /** 409 * clkdm_register_autodeps - register autodeps (if required) 410 * @ia: pointer to a static array of struct clkdm_autodep to register 411 * 412 * Register clockdomain "automatic dependencies." These are 413 * clockdomain wakeup and sleep dependencies that are automatically 414 * added whenever the first clock inside a clockdomain is enabled, and 415 * removed whenever the last clock inside a clockdomain is disabled. 416 * These are currently only used on OMAP3 devices, and are deprecated, 417 * since they waste energy. However, until the OMAP2/3 IP block 418 * enable/disable sequence can be converted to match the OMAP4 419 * sequence, they are needed. 420 * 421 * Must be called only after all of the SoC clockdomains are 422 * registered, since the function will resolve autodep clockdomain 423 * names into clockdomain pointers. 424 * 425 * The struct clkdm_autodep @ia array must be static, as this function 426 * does not copy the array elements. 427 * 428 * Returns -EACCES if called before any clockdomains have been 429 * registered, -EINVAL if called with a null @ia argument, -EEXIST if 430 * autodeps have already been registered, or 0 upon success. 431 */ 432 int clkdm_register_autodeps(struct clkdm_autodep *ia) 433 { 434 struct clkdm_autodep *a = NULL; 435 436 if (list_empty(&clkdm_list)) 437 return -EACCES; 438 439 if (!ia) 440 return -EINVAL; 441 442 if (autodeps) 443 return -EEXIST; 444 445 autodeps = ia; 446 for (a = autodeps; a->clkdm.ptr; a++) 447 _autodep_lookup(a); 448 449 return 0; 450 } 451 452 /** 453 * clkdm_complete_init - set up the clockdomain layer 454 * 455 * Put all clockdomains into software-supervised mode; PM code should 456 * later enable hardware-supervised mode as appropriate. Must be 457 * called after clkdm_register_clkdms(). Returns -EACCES if called 458 * before clkdm_register_clkdms(), or 0 upon success. 459 */ 460 int clkdm_complete_init(void) 461 { 462 struct clockdomain *clkdm; 463 464 if (list_empty(&clkdm_list)) 465 return -EACCES; 466 467 list_for_each_entry(clkdm, &clkdm_list, node) { 468 clkdm_deny_idle(clkdm); 469 470 _resolve_clkdm_deps(clkdm, clkdm->wkdep_srcs); 471 clkdm_clear_all_wkdeps(clkdm); 472 473 _resolve_clkdm_deps(clkdm, clkdm->sleepdep_srcs); 474 clkdm_clear_all_sleepdeps(clkdm); 475 } 476 477 return 0; 478 } 479 480 /** 481 * clkdm_lookup - look up a clockdomain by name, return a pointer 482 * @name: name of clockdomain 483 * 484 * Find a registered clockdomain by its name @name. Returns a pointer 485 * to the struct clockdomain if found, or NULL otherwise. 486 */ 487 struct clockdomain *clkdm_lookup(const char *name) 488 { 489 struct clockdomain *clkdm, *temp_clkdm; 490 491 if (!name) 492 return NULL; 493 494 clkdm = NULL; 495 496 list_for_each_entry(temp_clkdm, &clkdm_list, node) { 497 if (!strcmp(name, temp_clkdm->name)) { 498 clkdm = temp_clkdm; 499 break; 500 } 501 } 502 503 return clkdm; 504 } 505 506 /** 507 * clkdm_for_each - call function on each registered clockdomain 508 * @fn: callback function * 509 * 510 * Call the supplied function @fn for each registered clockdomain. 511 * The callback function @fn can return anything but 0 to bail 512 * out early from the iterator. The callback function is called with 513 * the clkdm_mutex held, so no clockdomain structure manipulation 514 * functions should be called from the callback, although hardware 515 * clockdomain control functions are fine. Returns the last return 516 * value of the callback function, which should be 0 for success or 517 * anything else to indicate failure; or -EINVAL if the function pointer 518 * is null. 519 */ 520 int clkdm_for_each(int (*fn)(struct clockdomain *clkdm, void *user), 521 void *user) 522 { 523 struct clockdomain *clkdm; 524 int ret = 0; 525 526 if (!fn) 527 return -EINVAL; 528 529 list_for_each_entry(clkdm, &clkdm_list, node) { 530 ret = (*fn)(clkdm, user); 531 if (ret) 532 break; 533 } 534 535 return ret; 536 } 537 538 539 /** 540 * clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in 541 * @clkdm: struct clockdomain * 542 * 543 * Return a pointer to the struct powerdomain that the specified clockdomain 544 * @clkdm exists in, or returns NULL if @clkdm is NULL. 545 */ 546 struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm) 547 { 548 if (!clkdm) 549 return NULL; 550 551 return clkdm->pwrdm.ptr; 552 } 553 554 555 /* Hardware clockdomain control */ 556 557 /** 558 * clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1 559 * @clkdm1: wake this struct clockdomain * up (dependent) 560 * @clkdm2: when this struct clockdomain * wakes up (source) 561 * 562 * When the clockdomain represented by @clkdm2 wakes up, wake up 563 * @clkdm1. Implemented in hardware on the OMAP, this feature is 564 * designed to reduce wakeup latency of the dependent clockdomain @clkdm1. 565 * Returns -EINVAL if presented with invalid clockdomain pointers, 566 * -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 0 upon 567 * success. 568 */ 569 int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2) 570 { 571 struct clkdm_dep *cd; 572 int ret; 573 574 if (!clkdm1 || !clkdm2) 575 return -EINVAL; 576 577 cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs); 578 if (IS_ERR(cd)) 579 return PTR_ERR(cd); 580 581 pwrdm_lock(cd->clkdm->pwrdm.ptr); 582 ret = _clkdm_add_wkdep(clkdm1, clkdm2); 583 pwrdm_unlock(cd->clkdm->pwrdm.ptr); 584 585 return ret; 586 } 587 588 /** 589 * clkdm_del_wkdep - remove a wakeup dependency from clkdm2 to clkdm1 590 * @clkdm1: wake this struct clockdomain * up (dependent) 591 * @clkdm2: when this struct clockdomain * wakes up (source) 592 * 593 * Remove a wakeup dependency causing @clkdm1 to wake up when @clkdm2 594 * wakes up. Returns -EINVAL if presented with invalid clockdomain 595 * pointers, -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 596 * 0 upon success. 597 */ 598 int clkdm_del_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2) 599 { 600 struct clkdm_dep *cd; 601 int ret; 602 603 if (!clkdm1 || !clkdm2) 604 return -EINVAL; 605 606 cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs); 607 if (IS_ERR(cd)) 608 return PTR_ERR(cd); 609 610 pwrdm_lock(cd->clkdm->pwrdm.ptr); 611 ret = _clkdm_del_wkdep(clkdm1, clkdm2); 612 pwrdm_unlock(cd->clkdm->pwrdm.ptr); 613 614 return ret; 615 } 616 617 /** 618 * clkdm_read_wkdep - read wakeup dependency state from clkdm2 to clkdm1 619 * @clkdm1: wake this struct clockdomain * up (dependent) 620 * @clkdm2: when this struct clockdomain * wakes up (source) 621 * 622 * Return 1 if a hardware wakeup dependency exists wherein @clkdm1 will be 623 * awoken when @clkdm2 wakes up; 0 if dependency is not set; -EINVAL 624 * if either clockdomain pointer is invalid; or -ENOENT if the hardware 625 * is incapable. 626 * 627 * REVISIT: Currently this function only represents software-controllable 628 * wakeup dependencies. Wakeup dependencies fixed in hardware are not 629 * yet handled here. 630 */ 631 int clkdm_read_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2) 632 { 633 struct clkdm_dep *cd; 634 int ret = 0; 635 636 if (!clkdm1 || !clkdm2) 637 return -EINVAL; 638 639 cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs); 640 if (IS_ERR(cd)) 641 ret = PTR_ERR(cd); 642 643 if (!arch_clkdm || !arch_clkdm->clkdm_read_wkdep) 644 ret = -EINVAL; 645 646 if (ret) { 647 pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n", 648 clkdm1->name, clkdm2->name); 649 return ret; 650 } 651 652 /* XXX It's faster to return the wkdep_usecount */ 653 return arch_clkdm->clkdm_read_wkdep(clkdm1, clkdm2); 654 } 655 656 /** 657 * clkdm_clear_all_wkdeps - remove all wakeup dependencies from target clkdm 658 * @clkdm: struct clockdomain * to remove all wakeup dependencies from 659 * 660 * Remove all inter-clockdomain wakeup dependencies that could cause 661 * @clkdm to wake. Intended to be used during boot to initialize the 662 * PRCM to a known state, after all clockdomains are put into swsup idle 663 * and woken up. Returns -EINVAL if @clkdm pointer is invalid, or 664 * 0 upon success. 665 */ 666 int clkdm_clear_all_wkdeps(struct clockdomain *clkdm) 667 { 668 if (!clkdm) 669 return -EINVAL; 670 671 if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_wkdeps) 672 return -EINVAL; 673 674 return arch_clkdm->clkdm_clear_all_wkdeps(clkdm); 675 } 676 677 /** 678 * clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1 679 * @clkdm1: prevent this struct clockdomain * from sleeping (dependent) 680 * @clkdm2: when this struct clockdomain * is active (source) 681 * 682 * Prevent @clkdm1 from automatically going inactive (and then to 683 * retention or off) if @clkdm2 is active. Returns -EINVAL if 684 * presented with invalid clockdomain pointers or called on a machine 685 * that does not support software-configurable hardware sleep 686 * dependencies, -ENOENT if the specified dependency cannot be set in 687 * hardware, or 0 upon success. 688 */ 689 int clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2) 690 { 691 struct clkdm_dep *cd; 692 int ret; 693 694 if (!clkdm1 || !clkdm2) 695 return -EINVAL; 696 697 cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs); 698 if (IS_ERR(cd)) 699 return PTR_ERR(cd); 700 701 pwrdm_lock(cd->clkdm->pwrdm.ptr); 702 ret = _clkdm_add_sleepdep(clkdm1, clkdm2); 703 pwrdm_unlock(cd->clkdm->pwrdm.ptr); 704 705 return ret; 706 } 707 708 /** 709 * clkdm_del_sleepdep - remove a sleep dependency from clkdm2 to clkdm1 710 * @clkdm1: prevent this struct clockdomain * from sleeping (dependent) 711 * @clkdm2: when this struct clockdomain * is active (source) 712 * 713 * Allow @clkdm1 to automatically go inactive (and then to retention or 714 * off), independent of the activity state of @clkdm2. Returns -EINVAL 715 * if presented with invalid clockdomain pointers or called on a machine 716 * that does not support software-configurable hardware sleep dependencies, 717 * -ENOENT if the specified dependency cannot be cleared in hardware, or 718 * 0 upon success. 719 */ 720 int clkdm_del_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2) 721 { 722 struct clkdm_dep *cd; 723 int ret; 724 725 if (!clkdm1 || !clkdm2) 726 return -EINVAL; 727 728 cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs); 729 if (IS_ERR(cd)) 730 return PTR_ERR(cd); 731 732 pwrdm_lock(cd->clkdm->pwrdm.ptr); 733 ret = _clkdm_del_sleepdep(clkdm1, clkdm2); 734 pwrdm_unlock(cd->clkdm->pwrdm.ptr); 735 736 return ret; 737 } 738 739 /** 740 * clkdm_read_sleepdep - read sleep dependency state from clkdm2 to clkdm1 741 * @clkdm1: prevent this struct clockdomain * from sleeping (dependent) 742 * @clkdm2: when this struct clockdomain * is active (source) 743 * 744 * Return 1 if a hardware sleep dependency exists wherein @clkdm1 will 745 * not be allowed to automatically go inactive if @clkdm2 is active; 746 * 0 if @clkdm1's automatic power state inactivity transition is independent 747 * of @clkdm2's; -EINVAL if either clockdomain pointer is invalid or called 748 * on a machine that does not support software-configurable hardware sleep 749 * dependencies; or -ENOENT if the hardware is incapable. 750 * 751 * REVISIT: Currently this function only represents software-controllable 752 * sleep dependencies. Sleep dependencies fixed in hardware are not 753 * yet handled here. 754 */ 755 int clkdm_read_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2) 756 { 757 struct clkdm_dep *cd; 758 int ret = 0; 759 760 if (!clkdm1 || !clkdm2) 761 return -EINVAL; 762 763 cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs); 764 if (IS_ERR(cd)) 765 ret = PTR_ERR(cd); 766 767 if (!arch_clkdm || !arch_clkdm->clkdm_read_sleepdep) 768 ret = -EINVAL; 769 770 if (ret) { 771 pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n", 772 clkdm1->name, clkdm2->name); 773 return ret; 774 } 775 776 /* XXX It's faster to return the sleepdep_usecount */ 777 return arch_clkdm->clkdm_read_sleepdep(clkdm1, clkdm2); 778 } 779 780 /** 781 * clkdm_clear_all_sleepdeps - remove all sleep dependencies from target clkdm 782 * @clkdm: struct clockdomain * to remove all sleep dependencies from 783 * 784 * Remove all inter-clockdomain sleep dependencies that could prevent 785 * @clkdm from idling. Intended to be used during boot to initialize the 786 * PRCM to a known state, after all clockdomains are put into swsup idle 787 * and woken up. Returns -EINVAL if @clkdm pointer is invalid, or 788 * 0 upon success. 789 */ 790 int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm) 791 { 792 if (!clkdm) 793 return -EINVAL; 794 795 if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_sleepdeps) 796 return -EINVAL; 797 798 return arch_clkdm->clkdm_clear_all_sleepdeps(clkdm); 799 } 800 801 /** 802 * clkdm_sleep_nolock - force clockdomain sleep transition (lockless) 803 * @clkdm: struct clockdomain * 804 * 805 * Instruct the CM to force a sleep transition on the specified 806 * clockdomain @clkdm. Only for use by the powerdomain code. Returns 807 * -EINVAL if @clkdm is NULL or if clockdomain does not support 808 * software-initiated sleep; 0 upon success. 809 */ 810 int clkdm_sleep_nolock(struct clockdomain *clkdm) 811 { 812 int ret; 813 814 if (!clkdm) 815 return -EINVAL; 816 817 if (!(clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) { 818 pr_debug("clockdomain: %s does not support forcing sleep via software\n", 819 clkdm->name); 820 return -EINVAL; 821 } 822 823 if (!arch_clkdm || !arch_clkdm->clkdm_sleep) 824 return -EINVAL; 825 826 pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name); 827 828 clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED; 829 ret = arch_clkdm->clkdm_sleep(clkdm); 830 ret |= pwrdm_state_switch_nolock(clkdm->pwrdm.ptr); 831 832 return ret; 833 } 834 835 /** 836 * clkdm_sleep - force clockdomain sleep transition 837 * @clkdm: struct clockdomain * 838 * 839 * Instruct the CM to force a sleep transition on the specified 840 * clockdomain @clkdm. Returns -EINVAL if @clkdm is NULL or if 841 * clockdomain does not support software-initiated sleep; 0 upon 842 * success. 843 */ 844 int clkdm_sleep(struct clockdomain *clkdm) 845 { 846 int ret; 847 848 pwrdm_lock(clkdm->pwrdm.ptr); 849 ret = clkdm_sleep_nolock(clkdm); 850 pwrdm_unlock(clkdm->pwrdm.ptr); 851 852 return ret; 853 } 854 855 /** 856 * clkdm_wakeup_nolock - force clockdomain wakeup transition (lockless) 857 * @clkdm: struct clockdomain * 858 * 859 * Instruct the CM to force a wakeup transition on the specified 860 * clockdomain @clkdm. Only for use by the powerdomain code. Returns 861 * -EINVAL if @clkdm is NULL or if the clockdomain does not support 862 * software-controlled wakeup; 0 upon success. 863 */ 864 int clkdm_wakeup_nolock(struct clockdomain *clkdm) 865 { 866 int ret; 867 868 if (!clkdm) 869 return -EINVAL; 870 871 if (!(clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)) { 872 pr_debug("clockdomain: %s does not support forcing wakeup via software\n", 873 clkdm->name); 874 return -EINVAL; 875 } 876 877 if (!arch_clkdm || !arch_clkdm->clkdm_wakeup) 878 return -EINVAL; 879 880 pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name); 881 882 clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED; 883 ret = arch_clkdm->clkdm_wakeup(clkdm); 884 ret |= pwrdm_state_switch_nolock(clkdm->pwrdm.ptr); 885 886 return ret; 887 } 888 889 /** 890 * clkdm_wakeup - force clockdomain wakeup transition 891 * @clkdm: struct clockdomain * 892 * 893 * Instruct the CM to force a wakeup transition on the specified 894 * clockdomain @clkdm. Returns -EINVAL if @clkdm is NULL or if the 895 * clockdomain does not support software-controlled wakeup; 0 upon 896 * success. 897 */ 898 int clkdm_wakeup(struct clockdomain *clkdm) 899 { 900 int ret; 901 902 pwrdm_lock(clkdm->pwrdm.ptr); 903 ret = clkdm_wakeup_nolock(clkdm); 904 pwrdm_unlock(clkdm->pwrdm.ptr); 905 906 return ret; 907 } 908 909 /** 910 * clkdm_allow_idle_nolock - enable hwsup idle transitions for clkdm 911 * @clkdm: struct clockdomain * 912 * 913 * Allow the hardware to automatically switch the clockdomain @clkdm 914 * into active or idle states, as needed by downstream clocks. If the 915 * clockdomain has any downstream clocks enabled in the clock 916 * framework, wkdep/sleepdep autodependencies are added; this is so 917 * device drivers can read and write to the device. Only for use by 918 * the powerdomain code. No return value. 919 */ 920 void clkdm_allow_idle_nolock(struct clockdomain *clkdm) 921 { 922 if (!clkdm) 923 return; 924 925 if (!WARN_ON(!clkdm->forcewake_count)) 926 clkdm->forcewake_count--; 927 928 if (clkdm->forcewake_count) 929 return; 930 931 if (!clkdm->usecount && (clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) 932 clkdm_sleep_nolock(clkdm); 933 934 if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO)) 935 return; 936 937 if (clkdm->flags & CLKDM_MISSING_IDLE_REPORTING) 938 return; 939 940 if (!arch_clkdm || !arch_clkdm->clkdm_allow_idle) 941 return; 942 943 pr_debug("clockdomain: enabling automatic idle transitions for %s\n", 944 clkdm->name); 945 946 clkdm->_flags |= _CLKDM_FLAG_HWSUP_ENABLED; 947 arch_clkdm->clkdm_allow_idle(clkdm); 948 pwrdm_state_switch_nolock(clkdm->pwrdm.ptr); 949 } 950 951 /** 952 * clkdm_allow_idle - enable hwsup idle transitions for clkdm 953 * @clkdm: struct clockdomain * 954 * 955 * Allow the hardware to automatically switch the clockdomain @clkdm into 956 * active or idle states, as needed by downstream clocks. If the 957 * clockdomain has any downstream clocks enabled in the clock 958 * framework, wkdep/sleepdep autodependencies are added; this is so 959 * device drivers can read and write to the device. No return value. 960 */ 961 void clkdm_allow_idle(struct clockdomain *clkdm) 962 { 963 pwrdm_lock(clkdm->pwrdm.ptr); 964 clkdm_allow_idle_nolock(clkdm); 965 pwrdm_unlock(clkdm->pwrdm.ptr); 966 } 967 968 /** 969 * clkdm_deny_idle - disable hwsup idle transitions for clkdm 970 * @clkdm: struct clockdomain * 971 * 972 * Prevent the hardware from automatically switching the clockdomain 973 * @clkdm into inactive or idle states. If the clockdomain has 974 * downstream clocks enabled in the clock framework, wkdep/sleepdep 975 * autodependencies are removed. Only for use by the powerdomain 976 * code. No return value. 977 */ 978 void clkdm_deny_idle_nolock(struct clockdomain *clkdm) 979 { 980 if (!clkdm) 981 return; 982 983 if (clkdm->forcewake_count++) 984 return; 985 986 if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP) 987 clkdm_wakeup_nolock(clkdm); 988 989 if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO)) 990 return; 991 992 if (clkdm->flags & CLKDM_MISSING_IDLE_REPORTING) 993 return; 994 995 if (!arch_clkdm || !arch_clkdm->clkdm_deny_idle) 996 return; 997 998 pr_debug("clockdomain: disabling automatic idle transitions for %s\n", 999 clkdm->name); 1000 1001 clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED; 1002 arch_clkdm->clkdm_deny_idle(clkdm); 1003 pwrdm_state_switch_nolock(clkdm->pwrdm.ptr); 1004 } 1005 1006 /** 1007 * clkdm_deny_idle - disable hwsup idle transitions for clkdm 1008 * @clkdm: struct clockdomain * 1009 * 1010 * Prevent the hardware from automatically switching the clockdomain 1011 * @clkdm into inactive or idle states. If the clockdomain has 1012 * downstream clocks enabled in the clock framework, wkdep/sleepdep 1013 * autodependencies are removed. No return value. 1014 */ 1015 void clkdm_deny_idle(struct clockdomain *clkdm) 1016 { 1017 pwrdm_lock(clkdm->pwrdm.ptr); 1018 clkdm_deny_idle_nolock(clkdm); 1019 pwrdm_unlock(clkdm->pwrdm.ptr); 1020 } 1021 1022 /** 1023 * clkdm_in_hwsup - is clockdomain @clkdm have hardware-supervised idle enabled? 1024 * @clkdm: struct clockdomain * 1025 * 1026 * Returns true if clockdomain @clkdm currently has 1027 * hardware-supervised idle enabled, or false if it does not or if 1028 * @clkdm is NULL. It is only valid to call this function after 1029 * clkdm_init() has been called. This function does not actually read 1030 * bits from the hardware; it instead tests an in-memory flag that is 1031 * changed whenever the clockdomain code changes the auto-idle mode. 1032 */ 1033 bool clkdm_in_hwsup(struct clockdomain *clkdm) 1034 { 1035 bool ret; 1036 1037 if (!clkdm) 1038 return false; 1039 1040 ret = (clkdm->_flags & _CLKDM_FLAG_HWSUP_ENABLED) ? true : false; 1041 1042 return ret; 1043 } 1044 1045 /** 1046 * clkdm_missing_idle_reporting - can @clkdm enter autoidle even if in use? 1047 * @clkdm: struct clockdomain * 1048 * 1049 * Returns true if clockdomain @clkdm has the 1050 * CLKDM_MISSING_IDLE_REPORTING flag set, or false if not or @clkdm is 1051 * null. More information is available in the documentation for the 1052 * CLKDM_MISSING_IDLE_REPORTING macro. 1053 */ 1054 bool clkdm_missing_idle_reporting(struct clockdomain *clkdm) 1055 { 1056 if (!clkdm) 1057 return false; 1058 1059 return (clkdm->flags & CLKDM_MISSING_IDLE_REPORTING) ? true : false; 1060 } 1061 1062 /* Public autodep handling functions (deprecated) */ 1063 1064 /** 1065 * clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable 1066 * @clkdm: struct clockdomain * 1067 * 1068 * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm' 1069 * in hardware-supervised mode. Meant to be called from clock framework 1070 * when a clock inside clockdomain 'clkdm' is enabled. No return value. 1071 * 1072 * XXX autodeps are deprecated and should be removed at the earliest 1073 * opportunity 1074 */ 1075 void clkdm_add_autodeps(struct clockdomain *clkdm) 1076 { 1077 struct clkdm_autodep *autodep; 1078 1079 if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS) 1080 return; 1081 1082 for (autodep = autodeps; autodep->clkdm.ptr; autodep++) { 1083 if (IS_ERR(autodep->clkdm.ptr)) 1084 continue; 1085 1086 pr_debug("clockdomain: %s: adding %s sleepdep/wkdep\n", 1087 clkdm->name, autodep->clkdm.ptr->name); 1088 1089 _clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr); 1090 _clkdm_add_wkdep(clkdm, autodep->clkdm.ptr); 1091 } 1092 } 1093 1094 /** 1095 * clkdm_del_autodeps - remove auto sleepdeps/wkdeps from clkdm 1096 * @clkdm: struct clockdomain * 1097 * 1098 * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm' 1099 * in hardware-supervised mode. Meant to be called from clock framework 1100 * when a clock inside clockdomain 'clkdm' is disabled. No return value. 1101 * 1102 * XXX autodeps are deprecated and should be removed at the earliest 1103 * opportunity 1104 */ 1105 void clkdm_del_autodeps(struct clockdomain *clkdm) 1106 { 1107 struct clkdm_autodep *autodep; 1108 1109 if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS) 1110 return; 1111 1112 for (autodep = autodeps; autodep->clkdm.ptr; autodep++) { 1113 if (IS_ERR(autodep->clkdm.ptr)) 1114 continue; 1115 1116 pr_debug("clockdomain: %s: removing %s sleepdep/wkdep\n", 1117 clkdm->name, autodep->clkdm.ptr->name); 1118 1119 _clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr); 1120 _clkdm_del_wkdep(clkdm, autodep->clkdm.ptr); 1121 } 1122 } 1123 1124 /* Clockdomain-to-clock/hwmod framework interface code */ 1125 1126 static int _clkdm_clk_hwmod_enable(struct clockdomain *clkdm) 1127 { 1128 if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_enable) 1129 return -EINVAL; 1130 1131 pwrdm_lock(clkdm->pwrdm.ptr); 1132 1133 /* 1134 * For arch's with no autodeps, clkcm_clk_enable 1135 * should be called for every clock instance or hwmod that is 1136 * enabled, so the clkdm can be force woken up. 1137 */ 1138 clkdm->usecount++; 1139 if (clkdm->usecount > 1 && autodeps) { 1140 pwrdm_unlock(clkdm->pwrdm.ptr); 1141 return 0; 1142 } 1143 1144 arch_clkdm->clkdm_clk_enable(clkdm); 1145 pwrdm_state_switch_nolock(clkdm->pwrdm.ptr); 1146 pwrdm_unlock(clkdm->pwrdm.ptr); 1147 1148 pr_debug("clockdomain: %s: enabled\n", clkdm->name); 1149 1150 return 0; 1151 } 1152 1153 /** 1154 * clkdm_clk_enable - add an enabled downstream clock to this clkdm 1155 * @clkdm: struct clockdomain * 1156 * @clk: struct clk * of the enabled downstream clock 1157 * 1158 * Increment the usecount of the clockdomain @clkdm and ensure that it 1159 * is awake before @clk is enabled. Intended to be called by 1160 * clk_enable() code. If the clockdomain is in software-supervised 1161 * idle mode, force the clockdomain to wake. If the clockdomain is in 1162 * hardware-supervised idle mode, add clkdm-pwrdm autodependencies, to 1163 * ensure that devices in the clockdomain can be read from/written to 1164 * by on-chip processors. Returns -EINVAL if passed null pointers; 1165 * returns 0 upon success or if the clockdomain is in hwsup idle mode. 1166 */ 1167 int clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk) 1168 { 1169 /* 1170 * XXX Rewrite this code to maintain a list of enabled 1171 * downstream clocks for debugging purposes? 1172 */ 1173 1174 if (!clk) 1175 return -EINVAL; 1176 1177 return _clkdm_clk_hwmod_enable(clkdm); 1178 } 1179 1180 /** 1181 * clkdm_clk_disable - remove an enabled downstream clock from this clkdm 1182 * @clkdm: struct clockdomain * 1183 * @clk: struct clk * of the disabled downstream clock 1184 * 1185 * Decrement the usecount of this clockdomain @clkdm when @clk is 1186 * disabled. Intended to be called by clk_disable() code. If the 1187 * clockdomain usecount goes to 0, put the clockdomain to sleep 1188 * (software-supervised mode) or remove the clkdm autodependencies 1189 * (hardware-supervised mode). Returns -EINVAL if passed null 1190 * pointers; -ERANGE if the @clkdm usecount underflows; or returns 0 1191 * upon success or if the clockdomain is in hwsup idle mode. 1192 */ 1193 int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk) 1194 { 1195 if (!clkdm || !clk || !arch_clkdm || !arch_clkdm->clkdm_clk_disable) 1196 return -EINVAL; 1197 1198 pwrdm_lock(clkdm->pwrdm.ptr); 1199 1200 /* corner case: disabling unused clocks */ 1201 if ((__clk_get_enable_count(clk) == 0) && clkdm->usecount == 0) 1202 goto ccd_exit; 1203 1204 if (clkdm->usecount == 0) { 1205 pwrdm_unlock(clkdm->pwrdm.ptr); 1206 WARN_ON(1); /* underflow */ 1207 return -ERANGE; 1208 } 1209 1210 clkdm->usecount--; 1211 if (clkdm->usecount > 0) { 1212 pwrdm_unlock(clkdm->pwrdm.ptr); 1213 return 0; 1214 } 1215 1216 arch_clkdm->clkdm_clk_disable(clkdm); 1217 pwrdm_state_switch_nolock(clkdm->pwrdm.ptr); 1218 1219 pr_debug("clockdomain: %s: disabled\n", clkdm->name); 1220 1221 ccd_exit: 1222 pwrdm_unlock(clkdm->pwrdm.ptr); 1223 1224 return 0; 1225 } 1226 1227 u32 clkdm_xlate_address(struct clockdomain *clkdm) 1228 { 1229 if (arch_clkdm->clkdm_xlate_address) 1230 return arch_clkdm->clkdm_xlate_address(clkdm); 1231 1232 return 0; 1233 } 1234 1235 /** 1236 * clkdm_hwmod_enable - add an enabled downstream hwmod to this clkdm 1237 * @clkdm: struct clockdomain * 1238 * @oh: struct omap_hwmod * of the enabled downstream hwmod 1239 * 1240 * Increment the usecount of the clockdomain @clkdm and ensure that it 1241 * is awake before @oh is enabled. Intended to be called by 1242 * module_enable() code. 1243 * If the clockdomain is in software-supervised idle mode, force the 1244 * clockdomain to wake. If the clockdomain is in hardware-supervised idle 1245 * mode, add clkdm-pwrdm autodependencies, to ensure that devices in the 1246 * clockdomain can be read from/written to by on-chip processors. 1247 * Returns -EINVAL if passed null pointers; 1248 * returns 0 upon success or if the clockdomain is in hwsup idle mode. 1249 */ 1250 int clkdm_hwmod_enable(struct clockdomain *clkdm, struct omap_hwmod *oh) 1251 { 1252 /* The clkdm attribute does not exist yet prior OMAP4 */ 1253 if (cpu_is_omap24xx() || cpu_is_omap34xx()) 1254 return 0; 1255 1256 /* 1257 * XXX Rewrite this code to maintain a list of enabled 1258 * downstream hwmods for debugging purposes? 1259 */ 1260 1261 if (!oh) 1262 return -EINVAL; 1263 1264 return _clkdm_clk_hwmod_enable(clkdm); 1265 } 1266 1267 /** 1268 * clkdm_hwmod_disable - remove an enabled downstream hwmod from this clkdm 1269 * @clkdm: struct clockdomain * 1270 * @oh: struct omap_hwmod * of the disabled downstream hwmod 1271 * 1272 * Decrement the usecount of this clockdomain @clkdm when @oh is 1273 * disabled. Intended to be called by module_disable() code. 1274 * If the clockdomain usecount goes to 0, put the clockdomain to sleep 1275 * (software-supervised mode) or remove the clkdm autodependencies 1276 * (hardware-supervised mode). 1277 * Returns -EINVAL if passed null pointers; -ERANGE if the @clkdm usecount 1278 * underflows; or returns 0 upon success or if the clockdomain is in hwsup 1279 * idle mode. 1280 */ 1281 int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh) 1282 { 1283 /* The clkdm attribute does not exist yet prior OMAP4 */ 1284 if (cpu_is_omap24xx() || cpu_is_omap34xx()) 1285 return 0; 1286 1287 /* 1288 * XXX Rewrite this code to maintain a list of enabled 1289 * downstream hwmods for debugging purposes? 1290 */ 1291 1292 if (!clkdm || !oh || !arch_clkdm || !arch_clkdm->clkdm_clk_disable) 1293 return -EINVAL; 1294 1295 pwrdm_lock(clkdm->pwrdm.ptr); 1296 1297 if (clkdm->usecount == 0) { 1298 pwrdm_unlock(clkdm->pwrdm.ptr); 1299 WARN_ON(1); /* underflow */ 1300 return -ERANGE; 1301 } 1302 1303 clkdm->usecount--; 1304 if (clkdm->usecount > 0) { 1305 pwrdm_unlock(clkdm->pwrdm.ptr); 1306 return 0; 1307 } 1308 1309 arch_clkdm->clkdm_clk_disable(clkdm); 1310 pwrdm_state_switch_nolock(clkdm->pwrdm.ptr); 1311 pwrdm_unlock(clkdm->pwrdm.ptr); 1312 1313 pr_debug("clockdomain: %s: disabled\n", clkdm->name); 1314 1315 return 0; 1316 } 1317 1318