release/src-rt-6.x.4708/linux/linux-2.6.36/arch/arm/mach-omap2/clockdomain.c

   1 /*
   2  * OMAP2/3/4 clockdomain framework functions
   3  *
   4  * Copyright (C) 2008-2010 Texas Instruments, Inc.
   5  * Copyright (C) 2008-2010 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/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/device.h>
  19 #include <linux/list.h>
  20 #include <linux/errno.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 "prm.h"
  31 #include "prm-regbits-24xx.h"
  32 #include "cm.h"
  33
  34 #include <plat/clock.h>
  35 #include <plat/powerdomain.h>
  36 #include <plat/clockdomain.h>
  37 #include <plat/prcm.h>
  38
  39 /* clkdm_list contains all registered struct clockdomains */
  40 static LIST_HEAD(clkdm_list);
  41
  42 /* array of clockdomain deps to be added/removed when clkdm in hwsup mode */
  43 static struct clkdm_autodep *autodeps;
  44
  45
  46 /* Private functions */
  47
  48 static struct clockdomain *_clkdm_lookup(const char *name)
  49 {
  50         struct clockdomain *clkdm, *temp_clkdm;
  51
  52         if (!name)
  53                 return NULL;
  54
  55         clkdm = NULL;
  56
  57         list_for_each_entry(temp_clkdm, &clkdm_list, node) {
  58                 if (!strcmp(name, temp_clkdm->name)) {
  59                         clkdm = temp_clkdm;
  60                         break;
  61                 }
  62         }
  63
  64         return clkdm;
  65 }
  66
  67 /**
  68  * _clkdm_register - register a clockdomain
  69  * @clkdm: struct clockdomain * to register
  70  *
  71  * Adds a clockdomain to the internal clockdomain list.
  72  * Returns -EINVAL if given a null pointer, -EEXIST if a clockdomain is
  73  * already registered by the provided name, or 0 upon success.
  74  */
  75 static int _clkdm_register(struct clockdomain *clkdm)
  76 {
  77         struct powerdomain *pwrdm;
  78
  79         if (!clkdm || !clkdm->name)
  80                 return -EINVAL;
  81
  82         if (!omap_chip_is(clkdm->omap_chip))
  83                 return -EINVAL;
  84
  85         pwrdm = pwrdm_lookup(clkdm->pwrdm.name);
  86         if (!pwrdm) {
  87                 pr_err("clockdomain: %s: powerdomain %s does not exist\n",
  88                         clkdm->name, clkdm->pwrdm.name);
  89                 return -EINVAL;
  90         }
  91         clkdm->pwrdm.ptr = pwrdm;
  92
  93         /* Verify that the clockdomain is not already registered */
  94         if (_clkdm_lookup(clkdm->name))
  95                 return -EEXIST;
  96
  97         list_add(&clkdm->node, &clkdm_list);
  98
  99         pwrdm_add_clkdm(pwrdm, clkdm);
 100
 101         pr_debug("clockdomain: registered %s\n", clkdm->name);
 102
 103         return 0;
 104 }
 105
 106 /* _clkdm_deps_lookup - look up the specified clockdomain in a clkdm list */
 107 static struct clkdm_dep *_clkdm_deps_lookup(struct clockdomain *clkdm,
 108                                             struct clkdm_dep *deps)
 109 {
 110         struct clkdm_dep *cd;
 111
 112         if (!clkdm || !deps || !omap_chip_is(clkdm->omap_chip))
 113                 return ERR_PTR(-EINVAL);
 114
 115         for (cd = deps; cd->clkdm_name; cd++) {
 116                 if (!omap_chip_is(cd->omap_chip))
 117                         continue;
 118
 119                 if (!cd->clkdm && cd->clkdm_name)
 120                         cd->clkdm = _clkdm_lookup(cd->clkdm_name);
 121
 122                 if (cd->clkdm == clkdm)
 123                         break;
 124         }
 125
 126         if (!cd->clkdm_name)
 127                 return ERR_PTR(-ENOENT);
 128
 129         return cd;
 130 }
 131
 132 /*
 133  * _autodep_lookup - resolve autodep clkdm names to clkdm pointers; store
 134  * @autodep: struct clkdm_autodep * to resolve
 135  *
 136  * Resolve autodep clockdomain names to clockdomain pointers via
 137  * clkdm_lookup() and store the pointers in the autodep structure.  An
 138  * "autodep" is a clockdomain sleep/wakeup dependency that is
 139  * automatically added and removed whenever clocks in the associated
 140  * clockdomain are enabled or disabled (respectively) when the
 141  * clockdomain is in hardware-supervised mode.  Meant to be called
 142  * once at clockdomain layer initialization, since these should remain
 143  * fixed for a particular architecture.  No return value.
 144  */
 145 static void _autodep_lookup(struct clkdm_autodep *autodep)
 146 {
 147         struct clockdomain *clkdm;
 148
 149         if (!autodep)
 150                 return;
 151
 152         if (!omap_chip_is(autodep->omap_chip))
 153                 return;
 154
 155         clkdm = clkdm_lookup(autodep->clkdm.name);
 156         if (!clkdm) {
 157                 pr_err("clockdomain: autodeps: clockdomain %s does not exist\n",
 158                          autodep->clkdm.name);
 159                 clkdm = ERR_PTR(-ENOENT);
 160         }
 161         autodep->clkdm.ptr = clkdm;
 162 }
 163
 164 /*
 165  * _clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
 166  * @clkdm: struct clockdomain *
 167  *
 168  * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm'
 169  * in hardware-supervised mode.  Meant to be called from clock framework
 170  * when a clock inside clockdomain 'clkdm' is enabled.  No return value.
 171  */
 172 static void _clkdm_add_autodeps(struct clockdomain *clkdm)
 173 {
 174         struct clkdm_autodep *autodep;
 175
 176         if (!autodeps)
 177                 return;
 178
 179         for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
 180                 if (IS_ERR(autodep->clkdm.ptr))
 181                         continue;
 182
 183                 if (!omap_chip_is(autodep->omap_chip))
 184                         continue;
 185
 186                 pr_debug("clockdomain: adding %s sleepdep/wkdep for "
 187                          "clkdm %s\n", autodep->clkdm.ptr->name,
 188                          clkdm->name);
 189
 190                 clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr);
 191                 clkdm_add_wkdep(clkdm, autodep->clkdm.ptr);
 192         }
 193 }
 194
 195 /*
 196  * _clkdm_add_autodeps - remove auto sleepdeps/wkdeps from clkdm
 197  * @clkdm: struct clockdomain *
 198  *
 199  * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm'
 200  * in hardware-supervised mode.  Meant to be called from clock framework
 201  * when a clock inside clockdomain 'clkdm' is disabled.  No return value.
 202  */
 203 static void _clkdm_del_autodeps(struct clockdomain *clkdm)
 204 {
 205         struct clkdm_autodep *autodep;
 206
 207         if (!autodeps)
 208                 return;
 209
 210         for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
 211                 if (IS_ERR(autodep->clkdm.ptr))
 212                         continue;
 213
 214                 if (!omap_chip_is(autodep->omap_chip))
 215                         continue;
 216
 217                 pr_debug("clockdomain: removing %s sleepdep/wkdep for "
 218                          "clkdm %s\n", autodep->clkdm.ptr->name,
 219                          clkdm->name);
 220
 221                 clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr);
 222                 clkdm_del_wkdep(clkdm, autodep->clkdm.ptr);
 223         }
 224 }
 225
 226 /*
 227  * _omap2_clkdm_set_hwsup - set the hwsup idle transition bit
 228  * @clkdm: struct clockdomain *
 229  * @enable: int 0 to disable, 1 to enable
 230  *
 231  * Internal helper for actually switching the bit that controls hwsup
 232  * idle transitions for clkdm.
 233  */
 234 static void _omap2_clkdm_set_hwsup(struct clockdomain *clkdm, int enable)
 235 {
 236         u32 bits, v;
 237
 238         if (cpu_is_omap24xx()) {
 239                 if (enable)
 240                         bits = OMAP24XX_CLKSTCTRL_ENABLE_AUTO;
 241                 else
 242                         bits = OMAP24XX_CLKSTCTRL_DISABLE_AUTO;
 243         } else if (cpu_is_omap34xx() || cpu_is_omap44xx()) {
 244                 if (enable)
 245                         bits = OMAP34XX_CLKSTCTRL_ENABLE_AUTO;
 246                 else
 247                         bits = OMAP34XX_CLKSTCTRL_DISABLE_AUTO;
 248         } else {
 249                 BUG();
 250         }
 251
 252         bits = bits << __ffs(clkdm->clktrctrl_mask);
 253
 254         v = __raw_readl(clkdm->clkstctrl_reg);
 255         v &= ~(clkdm->clktrctrl_mask);
 256         v |= bits;
 257         __raw_writel(v, clkdm->clkstctrl_reg);
 258
 259 }
 260
 261 /**
 262  * _init_wkdep_usecount - initialize wkdep usecounts to match hardware
 263  * @clkdm: clockdomain to initialize wkdep usecounts
 264  *
 265  * Initialize the wakeup dependency usecount variables for clockdomain @clkdm.
 266  * If a wakeup dependency is present in the hardware, the usecount will be
 267  * set to 1; otherwise, it will be set to 0.  Software should clear all
 268  * software wakeup dependencies prior to calling this function if it wishes
 269  * to ensure that all usecounts start at 0.  No return value.
 270  */
 271 static void _init_wkdep_usecount(struct clockdomain *clkdm)
 272 {
 273         u32 v;
 274         struct clkdm_dep *cd;
 275
 276         if (!clkdm->wkdep_srcs)
 277                 return;
 278
 279         for (cd = clkdm->wkdep_srcs; cd->clkdm_name; cd++) {
 280                 if (!omap_chip_is(cd->omap_chip))
 281                         continue;
 282
 283                 if (!cd->clkdm && cd->clkdm_name)
 284                         cd->clkdm = _clkdm_lookup(cd->clkdm_name);
 285
 286                 if (!cd->clkdm) {
 287                         WARN(!cd->clkdm, "clockdomain: %s: wkdep clkdm %s not "
 288                              "found\n", clkdm->name, cd->clkdm_name);
 289                         continue;
 290                 }
 291
 292                 v = prm_read_mod_bits_shift(clkdm->pwrdm.ptr->prcm_offs,
 293                                             PM_WKDEP,
 294                                             (1 << cd->clkdm->dep_bit));
 295
 296                 if (v)
 297                         pr_debug("clockdomain: %s: wakeup dependency already "
 298                                  "set to wake up when %s wakes\n",
 299                                  clkdm->name, cd->clkdm->name);
 300
 301                 atomic_set(&cd->wkdep_usecount, (v) ? 1 : 0);
 302         }
 303 }
 304
 305 /**
 306  * _init_sleepdep_usecount - initialize sleepdep usecounts to match hardware
 307  * @clkdm: clockdomain to initialize sleepdep usecounts
 308  *
 309  * Initialize the sleep dependency usecount variables for clockdomain @clkdm.
 310  * If a sleep dependency is present in the hardware, the usecount will be
 311  * set to 1; otherwise, it will be set to 0.  Software should clear all
 312  * software sleep dependencies prior to calling this function if it wishes
 313  * to ensure that all usecounts start at 0.  No return value.
 314  */
 315 static void _init_sleepdep_usecount(struct clockdomain *clkdm)
 316 {
 317         u32 v;
 318         struct clkdm_dep *cd;
 319
 320         if (!cpu_is_omap34xx())
 321                 return;
 322
 323         if (!clkdm->sleepdep_srcs)
 324                 return;
 325
 326         for (cd = clkdm->sleepdep_srcs; cd->clkdm_name; cd++) {
 327                 if (!omap_chip_is(cd->omap_chip))
 328                         continue;
 329
 330                 if (!cd->clkdm && cd->clkdm_name)
 331                         cd->clkdm = _clkdm_lookup(cd->clkdm_name);
 332
 333                 if (!cd->clkdm) {
 334                         WARN(!cd->clkdm, "clockdomain: %s: sleepdep clkdm %s "
 335                              "not found\n", clkdm->name, cd->clkdm_name);
 336                         continue;
 337                 }
 338
 339                 v = prm_read_mod_bits_shift(clkdm->pwrdm.ptr->prcm_offs,
 340                                             OMAP3430_CM_SLEEPDEP,
 341                                             (1 << cd->clkdm->dep_bit));
 342
 343                 if (v)
 344                         pr_debug("clockdomain: %s: sleep dependency already "
 345                                  "set to prevent from idling until %s "
 346                                  "idles\n", clkdm->name, cd->clkdm->name);
 347
 348                 atomic_set(&cd->sleepdep_usecount, (v) ? 1 : 0);
 349         }
 350 };
 351
 352 /* Public functions */
 353
 354 /**
 355  * clkdm_init - set up the clockdomain layer
 356  * @clkdms: optional pointer to an array of clockdomains to register
 357  * @init_autodeps: optional pointer to an array of autodeps to register
 358  *
 359  * Set up internal state.  If a pointer to an array of clockdomains
 360  * @clkdms was supplied, loop through the list of clockdomains,
 361  * register all that are available on the current platform. Similarly,
 362  * if a pointer to an array of clockdomain autodependencies
 363  * @init_autodeps was provided, register those.  No return value.
 364  */
 365 void clkdm_init(struct clockdomain **clkdms,
 366                 struct clkdm_autodep *init_autodeps)
 367 {
 368         struct clockdomain **c = NULL;
 369         struct clockdomain *clkdm;
 370         struct clkdm_autodep *autodep = NULL;
 371
 372         if (clkdms)
 373                 for (c = clkdms; *c; c++)
 374                         _clkdm_register(*c);
 375
 376         autodeps = init_autodeps;
 377         if (autodeps)
 378                 for (autodep = autodeps; autodep->clkdm.ptr; autodep++)
 379                         _autodep_lookup(autodep);
 380
 381         /*
 382          * Ensure that the *dep_usecount registers reflect the current
 383          * state of the PRCM.
 384          */
 385         list_for_each_entry(clkdm, &clkdm_list, node) {
 386                 _init_wkdep_usecount(clkdm);
 387                 _init_sleepdep_usecount(clkdm);
 388         }
 389 }
 390
 391 /**
 392  * clkdm_lookup - look up a clockdomain by name, return a pointer
 393  * @name: name of clockdomain
 394  *
 395  * Find a registered clockdomain by its name @name.  Returns a pointer
 396  * to the struct clockdomain if found, or NULL otherwise.
 397  */
 398 struct clockdomain *clkdm_lookup(const char *name)
 399 {
 400         struct clockdomain *clkdm, *temp_clkdm;
 401
 402         if (!name)
 403                 return NULL;
 404
 405         clkdm = NULL;
 406
 407         list_for_each_entry(temp_clkdm, &clkdm_list, node) {
 408                 if (!strcmp(name, temp_clkdm->name)) {
 409                         clkdm = temp_clkdm;
 410                         break;
 411                 }
 412         }
 413
 414         return clkdm;
 415 }
 416
 417 /**
 418  * clkdm_for_each - call function on each registered clockdomain
 419  * @fn: callback function *
 420  *
 421  * Call the supplied function @fn for each registered clockdomain.
 422  * The callback function @fn can return anything but 0 to bail
 423  * out early from the iterator.  The callback function is called with
 424  * the clkdm_mutex held, so no clockdomain structure manipulation
 425  * functions should be called from the callback, although hardware
 426  * clockdomain control functions are fine.  Returns the last return
 427  * value of the callback function, which should be 0 for success or
 428  * anything else to indicate failure; or -EINVAL if the function pointer
 429  * is null.
 430  */
 431 int clkdm_for_each(int (*fn)(struct clockdomain *clkdm, void *user),
 432                         void *user)
 433 {
 434         struct clockdomain *clkdm;
 435         int ret = 0;
 436
 437         if (!fn)
 438                 return -EINVAL;
 439
 440         list_for_each_entry(clkdm, &clkdm_list, node) {
 441                 ret = (*fn)(clkdm, user);
 442                 if (ret)
 443                         break;
 444         }
 445
 446         return ret;
 447 }
 448
 449
 450 /**
 451  * clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in
 452  * @clkdm: struct clockdomain *
 453  *
 454  * Return a pointer to the struct powerdomain that the specified clockdomain
 455  * @clkdm exists in, or returns NULL if @clkdm is NULL.
 456  */
 457 struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
 458 {
 459         if (!clkdm)
 460                 return NULL;
 461
 462         return clkdm->pwrdm.ptr;
 463 }
 464
 465
 466 /* Hardware clockdomain control */
 467
 468 /**
 469  * clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1
 470  * @clkdm1: wake this struct clockdomain * up (dependent)
 471  * @clkdm2: when this struct clockdomain * wakes up (source)
 472  *
 473  * When the clockdomain represented by @clkdm2 wakes up, wake up
 474  * @clkdm1. Implemented in hardware on the OMAP, this feature is
 475  * designed to reduce wakeup latency of the dependent clockdomain @clkdm1.
 476  * Returns -EINVAL if presented with invalid clockdomain pointers,
 477  * -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 0 upon
 478  * success.
 479  */
 480 int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 481 {
 482         struct clkdm_dep *cd;
 483
 484         if (!clkdm1 || !clkdm2)
 485                 return -EINVAL;
 486
 487         cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
 488         if (IS_ERR(cd)) {
 489                 pr_debug("clockdomain: hardware cannot set/clear wake up of "
 490                          "%s when %s wakes up\n", clkdm1->name, clkdm2->name);
 491                 return PTR_ERR(cd);
 492         }
 493
 494         if (atomic_inc_return(&cd->wkdep_usecount) == 1) {
 495                 pr_debug("clockdomain: hardware will wake up %s when %s wakes "
 496                          "up\n", clkdm1->name, clkdm2->name);
 497
 498                 prm_set_mod_reg_bits((1 << clkdm2->dep_bit),
 499                                      clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP);
 500         }
 501
 502         return 0;
 503 }
 504
 505 /**
 506  * clkdm_del_wkdep - remove a wakeup dependency from clkdm2 to clkdm1
 507  * @clkdm1: wake this struct clockdomain * up (dependent)
 508  * @clkdm2: when this struct clockdomain * wakes up (source)
 509  *
 510  * Remove a wakeup dependency causing @clkdm1 to wake up when @clkdm2
 511  * wakes up.  Returns -EINVAL if presented with invalid clockdomain
 512  * pointers, -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or
 513  * 0 upon success.
 514  */
 515 int clkdm_del_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 516 {
 517         struct clkdm_dep *cd;
 518
 519         if (!clkdm1 || !clkdm2)
 520                 return -EINVAL;
 521
 522         cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
 523         if (IS_ERR(cd)) {
 524                 pr_debug("clockdomain: hardware cannot set/clear wake up of "
 525                          "%s when %s wakes up\n", clkdm1->name, clkdm2->name);
 526                 return PTR_ERR(cd);
 527         }
 528
 529         if (atomic_dec_return(&cd->wkdep_usecount) == 0) {
 530                 pr_debug("clockdomain: hardware will no longer wake up %s "
 531                          "after %s wakes up\n", clkdm1->name, clkdm2->name);
 532
 533                 prm_clear_mod_reg_bits((1 << clkdm2->dep_bit),
 534                                        clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP);
 535         }
 536
 537         return 0;
 538 }
 539
 540 /**
 541  * clkdm_read_wkdep - read wakeup dependency state from clkdm2 to clkdm1
 542  * @clkdm1: wake this struct clockdomain * up (dependent)
 543  * @clkdm2: when this struct clockdomain * wakes up (source)
 544  *
 545  * Return 1 if a hardware wakeup dependency exists wherein @clkdm1 will be
 546  * awoken when @clkdm2 wakes up; 0 if dependency is not set; -EINVAL
 547  * if either clockdomain pointer is invalid; or -ENOENT if the hardware
 548  * is incapable.
 549  *
 550  * REVISIT: Currently this function only represents software-controllable
 551  * wakeup dependencies.  Wakeup dependencies fixed in hardware are not
 552  * yet handled here.
 553  */
 554 int clkdm_read_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 555 {
 556         struct clkdm_dep *cd;
 557
 558         if (!clkdm1 || !clkdm2)
 559                 return -EINVAL;
 560
 561         cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
 562         if (IS_ERR(cd)) {
 563                 pr_debug("clockdomain: hardware cannot set/clear wake up of "
 564                          "%s when %s wakes up\n", clkdm1->name, clkdm2->name);
 565                 return PTR_ERR(cd);
 566         }
 567
 568         return prm_read_mod_bits_shift(clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP,
 569                                        (1 << clkdm2->dep_bit));
 570 }
 571
 572 /**
 573  * clkdm_clear_all_wkdeps - remove all wakeup dependencies from target clkdm
 574  * @clkdm: struct clockdomain * to remove all wakeup dependencies from
 575  *
 576  * Remove all inter-clockdomain wakeup dependencies that could cause
 577  * @clkdm to wake.  Intended to be used during boot to initialize the
 578  * PRCM to a known state, after all clockdomains are put into swsup idle
 579  * and woken up.  Returns -EINVAL if @clkdm pointer is invalid, or
 580  * 0 upon success.
 581  */
 582 int clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
 583 {
 584         struct clkdm_dep *cd;
 585         u32 mask = 0;
 586
 587         if (!clkdm)
 588                 return -EINVAL;
 589
 590         for (cd = clkdm->wkdep_srcs; cd && cd->clkdm_name; cd++) {
 591                 if (!omap_chip_is(cd->omap_chip))
 592                         continue;
 593
 594                 /* PRM accesses are slow, so minimize them */
 595                 mask |= 1 << cd->clkdm->dep_bit;
 596                 atomic_set(&cd->wkdep_usecount, 0);
 597         }
 598
 599         prm_clear_mod_reg_bits(mask, clkdm->pwrdm.ptr->prcm_offs, PM_WKDEP);
 600
 601         return 0;
 602 }
 603
 604 /**
 605  * clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1
 606  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
 607  * @clkdm2: when this struct clockdomain * is active (source)
 608  *
 609  * Prevent @clkdm1 from automatically going inactive (and then to
 610  * retention or off) if @clkdm2 is active.  Returns -EINVAL if
 611  * presented with invalid clockdomain pointers or called on a machine
 612  * that does not support software-configurable hardware sleep
 613  * dependencies, -ENOENT if the specified dependency cannot be set in
 614  * hardware, or 0 upon success.
 615  */
 616 int clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 617 {
 618         struct clkdm_dep *cd;
 619
 620         if (!cpu_is_omap34xx())
 621                 return -EINVAL;
 622
 623         if (!clkdm1 || !clkdm2)
 624                 return -EINVAL;
 625
 626         cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
 627         if (IS_ERR(cd)) {
 628                 pr_debug("clockdomain: hardware cannot set/clear sleep "
 629                          "dependency affecting %s from %s\n", clkdm1->name,
 630                          clkdm2->name);
 631                 return PTR_ERR(cd);
 632         }
 633
 634         if (atomic_inc_return(&cd->sleepdep_usecount) == 1) {
 635                 pr_debug("clockdomain: will prevent %s from sleeping if %s "
 636                          "is active\n", clkdm1->name, clkdm2->name);
 637
 638                 cm_set_mod_reg_bits((1 << clkdm2->dep_bit),
 639                                     clkdm1->pwrdm.ptr->prcm_offs,
 640                                     OMAP3430_CM_SLEEPDEP);
 641         }
 642
 643         return 0;
 644 }
 645
 646 /**
 647  * clkdm_del_sleepdep - remove a sleep dependency from clkdm2 to clkdm1
 648  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
 649  * @clkdm2: when this struct clockdomain * is active (source)
 650  *
 651  * Allow @clkdm1 to automatically go inactive (and then to retention or
 652  * off), independent of the activity state of @clkdm2.  Returns -EINVAL
 653  * if presented with invalid clockdomain pointers or called on a machine
 654  * that does not support software-configurable hardware sleep dependencies,
 655  * -ENOENT if the specified dependency cannot be cleared in hardware, or
 656  * 0 upon success.
 657  */
 658 int clkdm_del_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 659 {
 660         struct clkdm_dep *cd;
 661
 662         if (!cpu_is_omap34xx())
 663                 return -EINVAL;
 664
 665         if (!clkdm1 || !clkdm2)
 666                 return -EINVAL;
 667
 668         cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
 669         if (IS_ERR(cd)) {
 670                 pr_debug("clockdomain: hardware cannot set/clear sleep "
 671                          "dependency affecting %s from %s\n", clkdm1->name,
 672                          clkdm2->name);
 673                 return PTR_ERR(cd);
 674         }
 675
 676         if (atomic_dec_return(&cd->sleepdep_usecount) == 0) {
 677                 pr_debug("clockdomain: will no longer prevent %s from "
 678                          "sleeping if %s is active\n", clkdm1->name,
 679                          clkdm2->name);
 680
 681                 cm_clear_mod_reg_bits((1 << clkdm2->dep_bit),
 682                                       clkdm1->pwrdm.ptr->prcm_offs,
 683                                       OMAP3430_CM_SLEEPDEP);
 684         }
 685
 686         return 0;
 687 }
 688
 689 /**
 690  * clkdm_read_sleepdep - read sleep dependency state from clkdm2 to clkdm1
 691  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
 692  * @clkdm2: when this struct clockdomain * is active (source)
 693  *
 694  * Return 1 if a hardware sleep dependency exists wherein @clkdm1 will
 695  * not be allowed to automatically go inactive if @clkdm2 is active;
 696  * 0 if @clkdm1's automatic power state inactivity transition is independent
 697  * of @clkdm2's; -EINVAL if either clockdomain pointer is invalid or called
 698  * on a machine that does not support software-configurable hardware sleep
 699  * dependencies; or -ENOENT if the hardware is incapable.
 700  *
 701  * REVISIT: Currently this function only represents software-controllable
 702  * sleep dependencies.  Sleep dependencies fixed in hardware are not
 703  * yet handled here.
 704  */
 705 int clkdm_read_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 706 {
 707         struct clkdm_dep *cd;
 708
 709         if (!cpu_is_omap34xx())
 710                 return -EINVAL;
 711
 712         if (!clkdm1 || !clkdm2)
 713                 return -EINVAL;
 714
 715         cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
 716         if (IS_ERR(cd)) {
 717                 pr_debug("clockdomain: hardware cannot set/clear sleep "
 718                          "dependency affecting %s from %s\n", clkdm1->name,
 719                          clkdm2->name);
 720                 return PTR_ERR(cd);
 721         }
 722
 723         return prm_read_mod_bits_shift(clkdm1->pwrdm.ptr->prcm_offs,
 724                                        OMAP3430_CM_SLEEPDEP,
 725                                        (1 << clkdm2->dep_bit));
 726 }
 727
 728 /**
 729  * clkdm_clear_all_sleepdeps - remove all sleep dependencies from target clkdm
 730  * @clkdm: struct clockdomain * to remove all sleep dependencies from
 731  *
 732  * Remove all inter-clockdomain sleep dependencies that could prevent
 733  * @clkdm from idling.  Intended to be used during boot to initialize the
 734  * PRCM to a known state, after all clockdomains are put into swsup idle
 735  * and woken up.  Returns -EINVAL if @clkdm pointer is invalid, or
 736  * 0 upon success.
 737  */
 738 int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm)
 739 {
 740         struct clkdm_dep *cd;
 741         u32 mask = 0;
 742
 743         if (!cpu_is_omap34xx())
 744                 return -EINVAL;
 745
 746         if (!clkdm)
 747                 return -EINVAL;
 748
 749         for (cd = clkdm->sleepdep_srcs; cd && cd->clkdm_name; cd++) {
 750                 if (!omap_chip_is(cd->omap_chip))
 751                         continue;
 752
 753                 /* PRM accesses are slow, so minimize them */
 754                 mask |= 1 << cd->clkdm->dep_bit;
 755                 atomic_set(&cd->sleepdep_usecount, 0);
 756         }
 757
 758         prm_clear_mod_reg_bits(mask, clkdm->pwrdm.ptr->prcm_offs,
 759                                OMAP3430_CM_SLEEPDEP);
 760
 761         return 0;
 762 }
 763
 764 /**
 765  * omap2_clkdm_clktrctrl_read - read the clkdm's current state transition mode
 766  * @clkdm: struct clkdm * of a clockdomain
 767  *
 768  * Return the clockdomain @clkdm current state transition mode from the
 769  * corresponding domain CM_CLKSTCTRL register.  Returns -EINVAL if @clkdm
 770  * is NULL or the current mode upon success.
 771  */
 772 static int omap2_clkdm_clktrctrl_read(struct clockdomain *clkdm)
 773 {
 774         u32 v;
 775
 776         if (!clkdm)
 777                 return -EINVAL;
 778
 779         v = __raw_readl(clkdm->clkstctrl_reg);
 780         v &= clkdm->clktrctrl_mask;
 781         v >>= __ffs(clkdm->clktrctrl_mask);
 782
 783         return v;
 784 }
 785
 786 /**
 787  * omap2_clkdm_sleep - force clockdomain sleep transition
 788  * @clkdm: struct clockdomain *
 789  *
 790  * Instruct the CM to force a sleep transition on the specified
 791  * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if
 792  * clockdomain does not support software-initiated sleep; 0 upon
 793  * success.
 794  */
 795 int omap2_clkdm_sleep(struct clockdomain *clkdm)
 796 {
 797         if (!clkdm)
 798                 return -EINVAL;
 799
 800         if (!(clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) {
 801                 pr_debug("clockdomain: %s does not support forcing "
 802                          "sleep via software\n", clkdm->name);
 803                 return -EINVAL;
 804         }
 805
 806         pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name);
 807
 808         if (cpu_is_omap24xx()) {
 809
 810                 cm_set_mod_reg_bits(OMAP24XX_FORCESTATE_MASK,
 811                             clkdm->pwrdm.ptr->prcm_offs, OMAP2_PM_PWSTCTRL);
 812
 813         } else if (cpu_is_omap34xx() || cpu_is_omap44xx()) {
 814
 815                 u32 bits = (OMAP34XX_CLKSTCTRL_FORCE_SLEEP <<
 816                          __ffs(clkdm->clktrctrl_mask));
 817
 818                 u32 v = __raw_readl(clkdm->clkstctrl_reg);
 819                 v &= ~(clkdm->clktrctrl_mask);
 820                 v |= bits;
 821                 __raw_writel(v, clkdm->clkstctrl_reg);
 822
 823         } else {
 824                 BUG();
 825         };
 826
 827         return 0;
 828 }
 829
 830 /**
 831  * omap2_clkdm_wakeup - force clockdomain wakeup transition
 832  * @clkdm: struct clockdomain *
 833  *
 834  * Instruct the CM to force a wakeup transition on the specified
 835  * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if the
 836  * clockdomain does not support software-controlled wakeup; 0 upon
 837  * success.
 838  */
 839 int omap2_clkdm_wakeup(struct clockdomain *clkdm)
 840 {
 841         if (!clkdm)
 842                 return -EINVAL;
 843
 844         if (!(clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)) {
 845                 pr_debug("clockdomain: %s does not support forcing "
 846                          "wakeup via software\n", clkdm->name);
 847                 return -EINVAL;
 848         }
 849
 850         pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name);
 851
 852         if (cpu_is_omap24xx()) {
 853
 854                 cm_clear_mod_reg_bits(OMAP24XX_FORCESTATE_MASK,
 855                               clkdm->pwrdm.ptr->prcm_offs, OMAP2_PM_PWSTCTRL);
 856
 857         } else if (cpu_is_omap34xx() || cpu_is_omap44xx()) {
 858
 859                 u32 bits = (OMAP34XX_CLKSTCTRL_FORCE_WAKEUP <<
 860                          __ffs(clkdm->clktrctrl_mask));
 861
 862                 u32 v = __raw_readl(clkdm->clkstctrl_reg);
 863                 v &= ~(clkdm->clktrctrl_mask);
 864                 v |= bits;
 865                 __raw_writel(v, clkdm->clkstctrl_reg);
 866
 867         } else {
 868                 BUG();
 869         };
 870
 871         return 0;
 872 }
 873
 874 /**
 875  * omap2_clkdm_allow_idle - enable hwsup idle transitions for clkdm
 876  * @clkdm: struct clockdomain *
 877  *
 878  * Allow the hardware to automatically switch the clockdomain @clkdm into
 879  * active or idle states, as needed by downstream clocks.  If the
 880  * clockdomain has any downstream clocks enabled in the clock
 881  * framework, wkdep/sleepdep autodependencies are added; this is so
 882  * device drivers can read and write to the device.  No return value.
 883  */
 884 void omap2_clkdm_allow_idle(struct clockdomain *clkdm)
 885 {
 886         if (!clkdm)
 887                 return;
 888
 889         if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO)) {
 890                 pr_debug("clock: automatic idle transitions cannot be enabled "
 891                          "on clockdomain %s\n", clkdm->name);
 892                 return;
 893         }
 894
 895         pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
 896                  clkdm->name);
 897
 898         if (cpu_is_omap44xx()) {
 899                 WARN_ONCE(1, "clockdomain: OMAP4 wakeup/sleep dependency "
 900                           "support is not yet implemented\n");
 901         } else {
 902                 if (atomic_read(&clkdm->usecount) > 0)
 903                         _clkdm_add_autodeps(clkdm);
 904         }
 905
 906         _omap2_clkdm_set_hwsup(clkdm, 1);
 907
 908         pwrdm_clkdm_state_switch(clkdm);
 909 }
 910
 911 /**
 912  * omap2_clkdm_deny_idle - disable hwsup idle transitions for clkdm
 913  * @clkdm: struct clockdomain *
 914  *
 915  * Prevent the hardware from automatically switching the clockdomain
 916  * @clkdm into inactive or idle states.  If the clockdomain has
 917  * downstream clocks enabled in the clock framework, wkdep/sleepdep
 918  * autodependencies are removed.  No return value.
 919  */
 920 void omap2_clkdm_deny_idle(struct clockdomain *clkdm)
 921 {
 922         if (!clkdm)
 923                 return;
 924
 925         if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO)) {
 926                 pr_debug("clockdomain: automatic idle transitions cannot be "
 927                          "disabled on %s\n", clkdm->name);
 928                 return;
 929         }
 930
 931         pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
 932                  clkdm->name);
 933
 934         _omap2_clkdm_set_hwsup(clkdm, 0);
 935
 936         if (cpu_is_omap44xx()) {
 937                 WARN_ONCE(1, "clockdomain: OMAP4 wakeup/sleep dependency "
 938                           "support is not yet implemented\n");
 939         } else {
 940                 if (atomic_read(&clkdm->usecount) > 0)
 941                         _clkdm_del_autodeps(clkdm);
 942         }
 943 }
 944
 945
 946 /* Clockdomain-to-clock framework interface code */
 947
 948 /**
 949  * omap2_clkdm_clk_enable - add an enabled downstream clock to this clkdm
 950  * @clkdm: struct clockdomain *
 951  * @clk: struct clk * of the enabled downstream clock
 952  *
 953  * Increment the usecount of the clockdomain @clkdm and ensure that it
 954  * is awake before @clk is enabled.  Intended to be called by
 955  * clk_enable() code.  If the clockdomain is in software-supervised
 956  * idle mode, force the clockdomain to wake.  If the clockdomain is in
 957  * hardware-supervised idle mode, add clkdm-pwrdm autodependencies, to
 958  * ensure that devices in the clockdomain can be read from/written to
 959  * by on-chip processors.  Returns -EINVAL if passed null pointers;
 960  * returns 0 upon success or if the clockdomain is in hwsup idle mode.
 961  */
 962 int omap2_clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
 963 {
 964         int v;
 965
 966
 967         if (!clkdm || !clk)
 968                 return -EINVAL;
 969
 970         if (atomic_inc_return(&clkdm->usecount) > 1)
 971                 return 0;
 972
 973         /* Clockdomain now has one enabled downstream clock */
 974
 975         pr_debug("clockdomain: clkdm %s: clk %s now enabled\n", clkdm->name,
 976                  clk->name);
 977
 978         if (!clkdm->clkstctrl_reg)
 979                 return 0;
 980
 981         v = omap2_clkdm_clktrctrl_read(clkdm);
 982
 983         if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||
 984             (cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO)) {
 985                 /* Disable HW transitions when we are changing deps */
 986                 _omap2_clkdm_set_hwsup(clkdm, 0);
 987                 _clkdm_add_autodeps(clkdm);
 988                 _omap2_clkdm_set_hwsup(clkdm, 1);
 989         } else {
 990                 omap2_clkdm_wakeup(clkdm);
 991         }
 992
 993         pwrdm_wait_transition(clkdm->pwrdm.ptr);
 994         pwrdm_clkdm_state_switch(clkdm);
 995
 996         return 0;
 997 }
 998
 999 /**
1000  * omap2_clkdm_clk_disable - remove an enabled downstream clock from this clkdm
1001  * @clkdm: struct clockdomain *
1002  * @clk: struct clk * of the disabled downstream clock
1003  *
1004  * Decrement the usecount of this clockdomain @clkdm when @clk is
1005  * disabled.  Intended to be called by clk_disable() code.  If the
1006  * clockdomain usecount goes to 0, put the clockdomain to sleep
1007  * (software-supervised mode) or remove the clkdm autodependencies
1008  * (hardware-supervised mode).  Returns -EINVAL if passed null
1009  * pointers; -ERANGE if the @clkdm usecount underflows and debugging
1010  * is enabled; or returns 0 upon success or if the clockdomain is in
1011  * hwsup idle mode.
1012  */
1013 int omap2_clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
1014 {
1015         int v;
1016
1017
1018         if (!clkdm || !clk)
1019                 return -EINVAL;
1020
1021 #ifdef DEBUG
1022         if (atomic_read(&clkdm->usecount) == 0) {
1023                 WARN_ON(1); /* underflow */
1024                 return -ERANGE;
1025         }
1026 #endif
1027
1028         if (atomic_dec_return(&clkdm->usecount) > 0)
1029                 return 0;
1030
1031         /* All downstream clocks of this clockdomain are now disabled */
1032
1033         pr_debug("clockdomain: clkdm %s: clk %s now disabled\n", clkdm->name,
1034                  clk->name);
1035
1036         if (!clkdm->clkstctrl_reg)
1037                 return 0;
1038
1039         v = omap2_clkdm_clktrctrl_read(clkdm);
1040
1041         if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||
1042             (cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO)) {
1043                 /* Disable HW transitions when we are changing deps */
1044                 _omap2_clkdm_set_hwsup(clkdm, 0);
1045                 _clkdm_del_autodeps(clkdm);
1046                 _omap2_clkdm_set_hwsup(clkdm, 1);
1047         } else {
1048                 omap2_clkdm_sleep(clkdm);
1049         }
1050
1051         pwrdm_clkdm_state_switch(clkdm);
1052
1053         return 0;
1054 }