arch/arm/plat-omap/omap_device.c

   1 /*
   2  * omap_device implementation
   3  *
   4  * Copyright (C) 2009-2010 Nokia Corporation
   5  * Paul Walmsley, Kevin Hilman
   6  *
   7  * Developed in collaboration with (alphabetical order): Benoit
   8  * Cousson, Thara Gopinath, Tony Lindgren, Rajendra Nayak, Vikram
   9  * Pandita, Sakari Poussa, Anand Sawant, Santosh Shilimkar, Richard
  10  * Woodruff
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  *
  16  * This code provides a consistent interface for OMAP device drivers
  17  * to control power management and interconnect properties of their
  18  * devices.
  19  *
  20  * In the medium- to long-term, this code should either be
  21  * a) implemented via arch-specific pointers in platform_data
  22  * or
  23  * b) implemented as a proper omap_bus/omap_device in Linux, no more
  24  *    platform_data func pointers
  25  *
  26  *
  27  * Guidelines for usage by driver authors:
  28  *
  29  * 1. These functions are intended to be used by device drivers via
  30  * function pointers in struct platform_data.  As an example,
  31  * omap_device_enable() should be passed to the driver as
  32  *
  33  * struct foo_driver_platform_data {
  34  * ...
  35  *      int (*device_enable)(struct platform_device *pdev);
  36  * ...
  37  * }
  38  *
  39  * Note that the generic "device_enable" name is used, rather than
  40  * "omap_device_enable".  This is so other architectures can pass in their
  41  * own enable/disable functions here.
  42  *
  43  * This should be populated during device setup:
  44  *
  45  * ...
  46  * pdata->device_enable = omap_device_enable;
  47  * ...
  48  *
  49  * 2. Drivers should first check to ensure the function pointer is not null
  50  * before calling it, as in:
  51  *
  52  * if (pdata->device_enable)
  53  *     pdata->device_enable(pdev);
  54  *
  55  * This allows other architectures that don't use similar device_enable()/
  56  * device_shutdown() functions to execute normally.
  57  *
  58  * ...
  59  *
  60  * Suggested usage by device drivers:
  61  *
  62  * During device initialization:
  63  * device_enable()
  64  *
  65  * During device idle:
  66  * (save remaining device context if necessary)
  67  * device_idle();
  68  *
  69  * During device resume:
  70  * device_enable();
  71  * (restore context if necessary)
  72  *
  73  * During device shutdown:
  74  * device_shutdown()
  75  * (device must be reinitialized at this point to use it again)
  76  *
  77  */
  78 #undef DEBUG
  79
  80 #include <linux/kernel.h>
  81 #include <linux/platform_device.h>
  82 #include <linux/slab.h>
  83 #include <linux/err.h>
  84 #include <linux/io.h>
  85 #include <linux/clk.h>
  86 #include <linux/clkdev.h>
  87 #include <linux/pm_runtime.h>
  88
  89 #include <plat/omap_device.h>
  90 #include <plat/omap_hwmod.h>
  91 #include <plat/clock.h>
  92
  93 /* These parameters are passed to _omap_device_{de,}activate() */
  94 #define USE_WAKEUP_LAT                  0
  95 #define IGNORE_WAKEUP_LAT               1
  96
  97 static int omap_device_register(struct platform_device *pdev);
  98 static int omap_early_device_register(struct platform_device *pdev);
  99
 100 /* Private functions */
 101
 102 /**
 103  * _omap_device_activate - increase device readiness
 104  * @od: struct omap_device *
 105  * @ignore_lat: increase to latency target (0) or full readiness (1)?
 106  *
 107  * Increase readiness of omap_device @od (thus decreasing device
 108  * wakeup latency, but consuming more power).  If @ignore_lat is
 109  * IGNORE_WAKEUP_LAT, make the omap_device fully active.  Otherwise,
 110  * if @ignore_lat is USE_WAKEUP_LAT, and the device's maximum wakeup
 111  * latency is greater than the requested maximum wakeup latency, step
 112  * backwards in the omap_device_pm_latency table to ensure the
 113  * device's maximum wakeup latency is less than or equal to the
 114  * requested maximum wakeup latency.  Returns 0.
 115  */
 116 static int _omap_device_activate(struct omap_device *od, u8 ignore_lat)
 117 {
 118         struct timespec a, b, c;
 119
 120         dev_dbg(&od->pdev.dev, "omap_device: activating\n");
 121
 122         while (od->pm_lat_level > 0) {
 123                 struct omap_device_pm_latency *odpl;
 124                 unsigned long long act_lat = 0;
 125
 126                 od->pm_lat_level--;
 127
 128                 odpl = od->pm_lats + od->pm_lat_level;
 129
 130                 if (!ignore_lat &&
 131                     (od->dev_wakeup_lat <= od->_dev_wakeup_lat_limit))
 132                         break;
 133
 134                 read_persistent_clock(&a);
 135
 136                 /* XXX check return code */
 137                 odpl->activate_func(od);
 138
 139                 read_persistent_clock(&b);
 140
 141                 c = timespec_sub(b, a);
 142                 act_lat = timespec_to_ns(&c);
 143
 144                 dev_dbg(&od->pdev.dev,
 145                         "omap_device: pm_lat %d: activate: elapsed time "
 146                         "%llu nsec\n", od->pm_lat_level, act_lat);
 147
 148                 if (act_lat > odpl->activate_lat) {
 149                         odpl->activate_lat_worst = act_lat;
 150                         if (odpl->flags & OMAP_DEVICE_LATENCY_AUTO_ADJUST) {
 151                                 odpl->activate_lat = act_lat;
 152                                 dev_dbg(&od->pdev.dev,
 153                                         "new worst case activate latency "
 154                                         "%d: %llu\n",
 155                                         od->pm_lat_level, act_lat);
 156                         } else
 157                                 dev_warn(&od->pdev.dev,
 158                                          "activate latency %d "
 159                                          "higher than exptected. (%llu > %d)\n",
 160                                          od->pm_lat_level, act_lat,
 161                                          odpl->activate_lat);
 162                 }
 163
 164                 od->dev_wakeup_lat -= odpl->activate_lat;
 165         }
 166
 167         return 0;
 168 }
 169
 170 /**
 171  * _omap_device_deactivate - decrease device readiness
 172  * @od: struct omap_device *
 173  * @ignore_lat: decrease to latency target (0) or full inactivity (1)?
 174  *
 175  * Decrease readiness of omap_device @od (thus increasing device
 176  * wakeup latency, but conserving power).  If @ignore_lat is
 177  * IGNORE_WAKEUP_LAT, make the omap_device fully inactive.  Otherwise,
 178  * if @ignore_lat is USE_WAKEUP_LAT, and the device's maximum wakeup
 179  * latency is less than the requested maximum wakeup latency, step
 180  * forwards in the omap_device_pm_latency table to ensure the device's
 181  * maximum wakeup latency is less than or equal to the requested
 182  * maximum wakeup latency.  Returns 0.
 183  */
 184 static int _omap_device_deactivate(struct omap_device *od, u8 ignore_lat)
 185 {
 186         struct timespec a, b, c;
 187
 188         dev_dbg(&od->pdev.dev, "omap_device: deactivating\n");
 189
 190         while (od->pm_lat_level < od->pm_lats_cnt) {
 191                 struct omap_device_pm_latency *odpl;
 192                 unsigned long long deact_lat = 0;
 193
 194                 odpl = od->pm_lats + od->pm_lat_level;
 195
 196                 if (!ignore_lat &&
 197                     ((od->dev_wakeup_lat + odpl->activate_lat) >
 198                      od->_dev_wakeup_lat_limit))
 199                         break;
 200
 201                 read_persistent_clock(&a);
 202
 203                 /* XXX check return code */
 204                 odpl->deactivate_func(od);
 205
 206                 read_persistent_clock(&b);
 207
 208                 c = timespec_sub(b, a);
 209                 deact_lat = timespec_to_ns(&c);
 210
 211                 dev_dbg(&od->pdev.dev,
 212                         "omap_device: pm_lat %d: deactivate: elapsed time "
 213                         "%llu nsec\n", od->pm_lat_level, deact_lat);
 214
 215                 if (deact_lat > odpl->deactivate_lat) {
 216                         odpl->deactivate_lat_worst = deact_lat;
 217                         if (odpl->flags & OMAP_DEVICE_LATENCY_AUTO_ADJUST) {
 218                                 odpl->deactivate_lat = deact_lat;
 219                                 dev_dbg(&od->pdev.dev,
 220                                         "new worst case deactivate latency "
 221                                         "%d: %llu\n",
 222                                         od->pm_lat_level, deact_lat);
 223                         } else
 224                                 dev_warn(&od->pdev.dev,
 225                                          "deactivate latency %d "
 226                                          "higher than exptected. (%llu > %d)\n",
 227                                          od->pm_lat_level, deact_lat,
 228                                          odpl->deactivate_lat);
 229                 }
 230
 231                 od->dev_wakeup_lat += odpl->activate_lat;
 232
 233                 od->pm_lat_level++;
 234         }
 235
 236         return 0;
 237 }
 238
 239 static void _add_clkdev(struct omap_device *od, const char *clk_alias,
 240                        const char *clk_name)
 241 {
 242         struct clk *r;
 243         struct clk_lookup *l;
 244
 245         if (!clk_alias || !clk_name)
 246                 return;
 247
 248         dev_dbg(&od->pdev.dev, "Creating %s -> %s\n", clk_alias, clk_name);
 249
 250         r = clk_get_sys(dev_name(&od->pdev.dev), clk_alias);
 251         if (!IS_ERR(r)) {
 252                 dev_warn(&od->pdev.dev,
 253                          "alias %s already exists\n", clk_alias);
 254                 clk_put(r);
 255                 return;
 256         }
 257
 258         r = omap_clk_get_by_name(clk_name);
 259         if (IS_ERR(r)) {
 260                 dev_err(&od->pdev.dev,
 261                         "omap_clk_get_by_name for %s failed\n", clk_name);
 262                 return;
 263         }
 264
 265         l = clkdev_alloc(r, clk_alias, dev_name(&od->pdev.dev));
 266         if (!l) {
 267                 dev_err(&od->pdev.dev,
 268                         "clkdev_alloc for %s failed\n", clk_alias);
 269                 return;
 270         }
 271
 272         clkdev_add(l);
 273 }
 274
 275 /**
 276  * _add_hwmod_clocks_clkdev - Add clkdev entry for hwmod optional clocks
 277  * and main clock
 278  * @od: struct omap_device *od
 279  * @oh: struct omap_hwmod *oh
 280  *
 281  * For the main clock and every optional clock present per hwmod per
 282  * omap_device, this function adds an entry in the clkdev table of the
 283  * form <dev-id=dev_name, con-id=role> if it does not exist already.
 284  *
 285  * The function is called from inside omap_device_build_ss(), after
 286  * omap_device_register.
 287  *
 288  * This allows drivers to get a pointer to its optional clocks based on its role
 289  * by calling clk_get(<dev*>, <role>).
 290  * In the case of the main clock, a "fck" alias is used.
 291  *
 292  * No return value.
 293  */
 294 static void _add_hwmod_clocks_clkdev(struct omap_device *od,
 295                                      struct omap_hwmod *oh)
 296 {
 297         int i;
 298
 299         _add_clkdev(od, "fck", oh->main_clk);
 300
 301         for (i = 0; i < oh->opt_clks_cnt; i++)
 302                 _add_clkdev(od, oh->opt_clks[i].role, oh->opt_clks[i].clk);
 303 }
 304
 305
 306 /* Public functions for use by core code */
 307
 308 /**
 309  * omap_device_get_context_loss_count - get lost context count
 310  * @od: struct omap_device *
 311  *
 312  * Using the primary hwmod, query the context loss count for this
 313  * device.
 314  *
 315  * Callers should consider context for this device lost any time this
 316  * function returns a value different than the value the caller got
 317  * the last time it called this function.
 318  *
 319  * If any hwmods exist for the omap_device assoiated with @pdev,
 320  * return the context loss counter for that hwmod, otherwise return
 321  * zero.
 322  */
 323 u32 omap_device_get_context_loss_count(struct platform_device *pdev)
 324 {
 325         struct omap_device *od;
 326         u32 ret = 0;
 327
 328         od = to_omap_device(pdev);
 329
 330         if (od->hwmods_cnt)
 331                 ret = omap_hwmod_get_context_loss_count(od->hwmods[0]);
 332
 333         return ret;
 334 }
 335
 336 /**
 337  * omap_device_count_resources - count number of struct resource entries needed
 338  * @od: struct omap_device *
 339  *
 340  * Count the number of struct resource entries needed for this
 341  * omap_device @od.  Used by omap_device_build_ss() to determine how
 342  * much memory to allocate before calling
 343  * omap_device_fill_resources().  Returns the count.
 344  */
 345 static int omap_device_count_resources(struct omap_device *od)
 346 {
 347         int c = 0;
 348         int i;
 349
 350         for (i = 0; i < od->hwmods_cnt; i++)
 351                 c += omap_hwmod_count_resources(od->hwmods[i]);
 352
 353         pr_debug("omap_device: %s: counted %d total resources across %d "
 354                  "hwmods\n", od->pdev.name, c, od->hwmods_cnt);
 355
 356         return c;
 357 }
 358
 359 /**
 360  * omap_device_fill_resources - fill in array of struct resource
 361  * @od: struct omap_device *
 362  * @res: pointer to an array of struct resource to be filled in
 363  *
 364  * Populate one or more empty struct resource pointed to by @res with
 365  * the resource data for this omap_device @od.  Used by
 366  * omap_device_build_ss() after calling omap_device_count_resources().
 367  * Ideally this function would not be needed at all.  If omap_device
 368  * replaces platform_device, then we can specify our own
 369  * get_resource()/ get_irq()/etc functions that use the underlying
 370  * omap_hwmod information.  Or if platform_device is extended to use
 371  * subarchitecture-specific function pointers, the various
 372  * platform_device functions can simply call omap_device internal
 373  * functions to get device resources.  Hacking around the existing
 374  * platform_device code wastes memory.  Returns 0.
 375  */
 376 static int omap_device_fill_resources(struct omap_device *od,
 377                                       struct resource *res)
 378 {
 379         int c = 0;
 380         int i, r;
 381
 382         for (i = 0; i < od->hwmods_cnt; i++) {
 383                 r = omap_hwmod_fill_resources(od->hwmods[i], res);
 384                 res += r;
 385                 c += r;
 386         }
 387
 388         return 0;
 389 }
 390
 391 /**
 392  * omap_device_build - build and register an omap_device with one omap_hwmod
 393  * @pdev_name: name of the platform_device driver to use
 394  * @pdev_id: this platform_device's connection ID
 395  * @oh: ptr to the single omap_hwmod that backs this omap_device
 396  * @pdata: platform_data ptr to associate with the platform_device
 397  * @pdata_len: amount of memory pointed to by @pdata
 398  * @pm_lats: pointer to a omap_device_pm_latency array for this device
 399  * @pm_lats_cnt: ARRAY_SIZE() of @pm_lats
 400  * @is_early_device: should the device be registered as an early device or not
 401  *
 402  * Convenience function for building and registering a single
 403  * omap_device record, which in turn builds and registers a
 404  * platform_device record.  See omap_device_build_ss() for more
 405  * information.  Returns ERR_PTR(-EINVAL) if @oh is NULL; otherwise,
 406  * passes along the return value of omap_device_build_ss().
 407  */
 408 struct platform_device *omap_device_build(const char *pdev_name, int pdev_id,
 409                                       struct omap_hwmod *oh, void *pdata,
 410                                       int pdata_len,
 411                                       struct omap_device_pm_latency *pm_lats,
 412                                       int pm_lats_cnt, int is_early_device)
 413 {
 414         struct omap_hwmod *ohs[] = { oh };
 415
 416         if (!oh)
 417                 return ERR_PTR(-EINVAL);
 418
 419         return omap_device_build_ss(pdev_name, pdev_id, ohs, 1, pdata,
 420                                     pdata_len, pm_lats, pm_lats_cnt,
 421                                     is_early_device);
 422 }
 423
 424 /**
 425  * omap_device_build_ss - build and register an omap_device with multiple hwmods
 426  * @pdev_name: name of the platform_device driver to use
 427  * @pdev_id: this platform_device's connection ID
 428  * @oh: ptr to the single omap_hwmod that backs this omap_device
 429  * @pdata: platform_data ptr to associate with the platform_device
 430  * @pdata_len: amount of memory pointed to by @pdata
 431  * @pm_lats: pointer to a omap_device_pm_latency array for this device
 432  * @pm_lats_cnt: ARRAY_SIZE() of @pm_lats
 433  * @is_early_device: should the device be registered as an early device or not
 434  *
 435  * Convenience function for building and registering an omap_device
 436  * subsystem record.  Subsystem records consist of multiple
 437  * omap_hwmods.  This function in turn builds and registers a
 438  * platform_device record.  Returns an ERR_PTR() on error, or passes
 439  * along the return value of omap_device_register().
 440  */
 441 struct platform_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
 442                                          struct omap_hwmod **ohs, int oh_cnt,
 443                                          void *pdata, int pdata_len,
 444                                          struct omap_device_pm_latency *pm_lats,
 445                                          int pm_lats_cnt, int is_early_device)
 446 {
 447         int ret = -ENOMEM;
 448         struct omap_device *od;
 449         char *pdev_name2;
 450         struct resource *res = NULL;
 451         int i, res_count;
 452         struct omap_hwmod **hwmods;
 453
 454         if (!ohs || oh_cnt == 0 || !pdev_name)
 455                 return ERR_PTR(-EINVAL);
 456
 457         if (!pdata && pdata_len > 0)
 458                 return ERR_PTR(-EINVAL);
 459
 460         pr_debug("omap_device: %s: building with %d hwmods\n", pdev_name,
 461                  oh_cnt);
 462
 463         od = kzalloc(sizeof(struct omap_device), GFP_KERNEL);
 464         if (!od)
 465                 return ERR_PTR(-ENOMEM);
 466
 467         od->hwmods_cnt = oh_cnt;
 468
 469         hwmods = kzalloc(sizeof(struct omap_hwmod *) * oh_cnt,
 470                          GFP_KERNEL);
 471         if (!hwmods)
 472                 goto odbs_exit1;
 473
 474         memcpy(hwmods, ohs, sizeof(struct omap_hwmod *) * oh_cnt);
 475         od->hwmods = hwmods;
 476
 477         pdev_name2 = kzalloc(strlen(pdev_name) + 1, GFP_KERNEL);
 478         if (!pdev_name2)
 479                 goto odbs_exit2;
 480         strcpy(pdev_name2, pdev_name);
 481
 482         od->pdev.name = pdev_name2;
 483         od->pdev.id = pdev_id;
 484
 485         res_count = omap_device_count_resources(od);
 486         if (res_count > 0) {
 487                 res = kzalloc(sizeof(struct resource) * res_count, GFP_KERNEL);
 488                 if (!res)
 489                         goto odbs_exit3;
 490         }
 491         omap_device_fill_resources(od, res);
 492
 493         od->pdev.num_resources = res_count;
 494         od->pdev.resource = res;
 495
 496         ret = platform_device_add_data(&od->pdev, pdata, pdata_len);
 497         if (ret)
 498                 goto odbs_exit4;
 499
 500         od->pm_lats = pm_lats;
 501         od->pm_lats_cnt = pm_lats_cnt;
 502
 503         if (is_early_device)
 504                 ret = omap_early_device_register(&od->pdev);
 505         else
 506                 ret = omap_device_register(&od->pdev);
 507
 508         for (i = 0; i < oh_cnt; i++) {
 509                 hwmods[i]->od = od;
 510                 _add_hwmod_clocks_clkdev(od, hwmods[i]);
 511         }
 512
 513         if (ret)
 514                 goto odbs_exit4;
 515
 516         return &od->pdev;
 517
 518 odbs_exit4:
 519         kfree(res);
 520 odbs_exit3:
 521         kfree(pdev_name2);
 522 odbs_exit2:
 523         kfree(hwmods);
 524 odbs_exit1:
 525         kfree(od);
 526
 527         pr_err("omap_device: %s: build failed (%d)\n", pdev_name, ret);
 528
 529         return ERR_PTR(ret);
 530 }
 531
 532 /**
 533  * omap_early_device_register - register an omap_device as an early platform
 534  * device.
 535  * @od: struct omap_device * to register
 536  *
 537  * Register the omap_device structure.  This currently just calls
 538  * platform_early_add_device() on the underlying platform_device.
 539  * Returns 0 by default.
 540  */
 541 static int omap_early_device_register(struct platform_device *pdev)
 542 {
 543         struct platform_device *devices[1];
 544
 545         devices[0] = pdev;
 546         early_platform_add_devices(devices, 1);
 547         return 0;
 548 }
 549
 550 #ifdef CONFIG_PM_RUNTIME
 551 static int _od_runtime_suspend(struct device *dev)
 552 {
 553         struct platform_device *pdev = to_platform_device(dev);
 554         int ret;
 555
 556         ret = pm_generic_runtime_suspend(dev);
 557
 558         if (!ret)
 559                 omap_device_idle(pdev);
 560
 561         return ret;
 562 }
 563
 564 static int _od_runtime_idle(struct device *dev)
 565 {
 566         return pm_generic_runtime_idle(dev);
 567 }
 568
 569 static int _od_runtime_resume(struct device *dev)
 570 {
 571         struct platform_device *pdev = to_platform_device(dev);
 572
 573         omap_device_enable(pdev);
 574
 575         return pm_generic_runtime_resume(dev);
 576 }
 577 #endif
 578
 579 #ifdef CONFIG_SUSPEND
 580 static int _od_suspend_noirq(struct device *dev)
 581 {
 582         struct platform_device *pdev = to_platform_device(dev);
 583         struct omap_device *od = to_omap_device(pdev);
 584         int ret;
 585
 586         if (od->flags & OMAP_DEVICE_NO_IDLE_ON_SUSPEND)
 587                 return pm_generic_suspend_noirq(dev);
 588
 589         ret = pm_generic_suspend_noirq(dev);
 590
 591         if (!ret && !pm_runtime_status_suspended(dev)) {
 592                 if (pm_generic_runtime_suspend(dev) == 0) {
 593                         omap_device_idle(pdev);
 594                         od->flags |= OMAP_DEVICE_SUSPENDED;
 595                 }
 596         }
 597
 598         return ret;
 599 }
 600
 601 static int _od_resume_noirq(struct device *dev)
 602 {
 603         struct platform_device *pdev = to_platform_device(dev);
 604         struct omap_device *od = to_omap_device(pdev);
 605
 606         if (od->flags & OMAP_DEVICE_NO_IDLE_ON_SUSPEND)
 607                 return pm_generic_resume_noirq(dev);
 608
 609         if ((od->flags & OMAP_DEVICE_SUSPENDED) &&
 610             !pm_runtime_status_suspended(dev)) {
 611                 od->flags &= ~OMAP_DEVICE_SUSPENDED;
 612                 omap_device_enable(pdev);
 613                 pm_generic_runtime_resume(dev);
 614         }
 615
 616         return pm_generic_resume_noirq(dev);
 617 }
 618 #else
 619 #define _od_suspend_noirq NULL
 620 #define _od_resume_noirq NULL
 621 #endif
 622
 623 static struct dev_pm_domain omap_device_pm_domain = {
 624         .ops = {
 625                 SET_RUNTIME_PM_OPS(_od_runtime_suspend, _od_runtime_resume,
 626                                    _od_runtime_idle)
 627                 USE_PLATFORM_PM_SLEEP_OPS
 628                 .suspend_noirq = _od_suspend_noirq,
 629                 .resume_noirq = _od_resume_noirq,
 630         }
 631 };
 632
 633 /**
 634  * omap_device_register - register an omap_device with one omap_hwmod
 635  * @od: struct omap_device * to register
 636  *
 637  * Register the omap_device structure.  This currently just calls
 638  * platform_device_register() on the underlying platform_device.
 639  * Returns the return value of platform_device_register().
 640  */
 641 static int omap_device_register(struct platform_device *pdev)
 642 {
 643         pr_debug("omap_device: %s: registering\n", pdev->name);
 644
 645         pdev->dev.parent = &omap_device_parent;
 646         pdev->dev.pm_domain = &omap_device_pm_domain;
 647         return platform_device_register(pdev);
 648 }
 649
 650
 651 /* Public functions for use by device drivers through struct platform_data */
 652
 653 /**
 654  * omap_device_enable - fully activate an omap_device
 655  * @od: struct omap_device * to activate
 656  *
 657  * Do whatever is necessary for the hwmods underlying omap_device @od
 658  * to be accessible and ready to operate.  This generally involves
 659  * enabling clocks, setting SYSCONFIG registers; and in the future may
 660  * involve remuxing pins.  Device drivers should call this function
 661  * (through platform_data function pointers) where they would normally
 662  * enable clocks, etc.  Returns -EINVAL if called when the omap_device
 663  * is already enabled, or passes along the return value of
 664  * _omap_device_activate().
 665  */
 666 int omap_device_enable(struct platform_device *pdev)
 667 {
 668         int ret;
 669         struct omap_device *od;
 670
 671         od = to_omap_device(pdev);
 672
 673         if (od->_state == OMAP_DEVICE_STATE_ENABLED) {
 674                 dev_warn(&pdev->dev,
 675                          "omap_device: %s() called from invalid state %d\n",
 676                          __func__, od->_state);
 677                 return -EINVAL;
 678         }
 679
 680         /* Enable everything if we're enabling this device from scratch */
 681         if (od->_state == OMAP_DEVICE_STATE_UNKNOWN)
 682                 od->pm_lat_level = od->pm_lats_cnt;
 683
 684         ret = _omap_device_activate(od, IGNORE_WAKEUP_LAT);
 685
 686         od->dev_wakeup_lat = 0;
 687         od->_dev_wakeup_lat_limit = UINT_MAX;
 688         od->_state = OMAP_DEVICE_STATE_ENABLED;
 689
 690         return ret;
 691 }
 692
 693 /**
 694  * omap_device_idle - idle an omap_device
 695  * @od: struct omap_device * to idle
 696  *
 697  * Idle omap_device @od by calling as many .deactivate_func() entries
 698  * in the omap_device's pm_lats table as is possible without exceeding
 699  * the device's maximum wakeup latency limit, pm_lat_limit.  Device
 700  * drivers should call this function (through platform_data function
 701  * pointers) where they would normally disable clocks after operations
 702  * complete, etc..  Returns -EINVAL if the omap_device is not
 703  * currently enabled, or passes along the return value of
 704  * _omap_device_deactivate().
 705  */
 706 int omap_device_idle(struct platform_device *pdev)
 707 {
 708         int ret;
 709         struct omap_device *od;
 710
 711         od = to_omap_device(pdev);
 712
 713         if (od->_state != OMAP_DEVICE_STATE_ENABLED) {
 714                 dev_warn(&pdev->dev,
 715                          "omap_device: %s() called from invalid state %d\n",
 716                          __func__, od->_state);
 717                 return -EINVAL;
 718         }
 719
 720         ret = _omap_device_deactivate(od, USE_WAKEUP_LAT);
 721
 722         od->_state = OMAP_DEVICE_STATE_IDLE;
 723
 724         return ret;
 725 }
 726
 727 /**
 728  * omap_device_shutdown - shut down an omap_device
 729  * @od: struct omap_device * to shut down
 730  *
 731  * Shut down omap_device @od by calling all .deactivate_func() entries
 732  * in the omap_device's pm_lats table and then shutting down all of
 733  * the underlying omap_hwmods.  Used when a device is being "removed"
 734  * or a device driver is being unloaded.  Returns -EINVAL if the
 735  * omap_device is not currently enabled or idle, or passes along the
 736  * return value of _omap_device_deactivate().
 737  */
 738 int omap_device_shutdown(struct platform_device *pdev)
 739 {
 740         int ret, i;
 741         struct omap_device *od;
 742
 743         od = to_omap_device(pdev);
 744
 745         if (od->_state != OMAP_DEVICE_STATE_ENABLED &&
 746             od->_state != OMAP_DEVICE_STATE_IDLE) {
 747                 dev_warn(&pdev->dev,
 748                          "omap_device: %s() called from invalid state %d\n",
 749                          __func__, od->_state);
 750                 return -EINVAL;
 751         }
 752
 753         ret = _omap_device_deactivate(od, IGNORE_WAKEUP_LAT);
 754
 755         for (i = 0; i < od->hwmods_cnt; i++)
 756                 omap_hwmod_shutdown(od->hwmods[i]);
 757
 758         od->_state = OMAP_DEVICE_STATE_SHUTDOWN;
 759
 760         return ret;
 761 }
 762
 763 /**
 764  * omap_device_align_pm_lat - activate/deactivate device to match wakeup lat lim
 765  * @od: struct omap_device *
 766  *
 767  * When a device's maximum wakeup latency limit changes, call some of
 768  * the .activate_func or .deactivate_func function pointers in the
 769  * omap_device's pm_lats array to ensure that the device's maximum
 770  * wakeup latency is less than or equal to the new latency limit.
 771  * Intended to be called by OMAP PM code whenever a device's maximum
 772  * wakeup latency limit changes (e.g., via
 773  * omap_pm_set_dev_wakeup_lat()).  Returns 0 if nothing needs to be
 774  * done (e.g., if the omap_device is not currently idle, or if the
 775  * wakeup latency is already current with the new limit) or passes
 776  * along the return value of _omap_device_deactivate() or
 777  * _omap_device_activate().
 778  */
 779 int omap_device_align_pm_lat(struct platform_device *pdev,
 780                              u32 new_wakeup_lat_limit)
 781 {
 782         int ret = -EINVAL;
 783         struct omap_device *od;
 784
 785         od = to_omap_device(pdev);
 786
 787         if (new_wakeup_lat_limit == od->dev_wakeup_lat)
 788                 return 0;
 789
 790         od->_dev_wakeup_lat_limit = new_wakeup_lat_limit;
 791
 792         if (od->_state != OMAP_DEVICE_STATE_IDLE)
 793                 return 0;
 794         else if (new_wakeup_lat_limit > od->dev_wakeup_lat)
 795                 ret = _omap_device_deactivate(od, USE_WAKEUP_LAT);
 796         else if (new_wakeup_lat_limit < od->dev_wakeup_lat)
 797                 ret = _omap_device_activate(od, USE_WAKEUP_LAT);
 798
 799         return ret;
 800 }
 801
 802 /**
 803  * omap_device_get_pwrdm - return the powerdomain * associated with @od
 804  * @od: struct omap_device *
 805  *
 806  * Return the powerdomain associated with the first underlying
 807  * omap_hwmod for this omap_device.  Intended for use by core OMAP PM
 808  * code.  Returns NULL on error or a struct powerdomain * upon
 809  * success.
 810  */
 811 struct powerdomain *omap_device_get_pwrdm(struct omap_device *od)
 812 {
 813         /*
 814          * XXX Assumes that all omap_hwmod powerdomains are identical.
 815          * This may not necessarily be true.  There should be a sanity
 816          * check in here to WARN() if any difference appears.
 817          */
 818         if (!od->hwmods_cnt)
 819                 return NULL;
 820
 821         return omap_hwmod_get_pwrdm(od->hwmods[0]);
 822 }
 823
 824 /**
 825  * omap_device_get_mpu_rt_va - return the MPU's virtual addr for the hwmod base
 826  * @od: struct omap_device *
 827  *
 828  * Return the MPU's virtual address for the base of the hwmod, from
 829  * the ioremap() that the hwmod code does.  Only valid if there is one
 830  * hwmod associated with this device.  Returns NULL if there are zero
 831  * or more than one hwmods associated with this omap_device;
 832  * otherwise, passes along the return value from
 833  * omap_hwmod_get_mpu_rt_va().
 834  */
 835 void __iomem *omap_device_get_rt_va(struct omap_device *od)
 836 {
 837         if (od->hwmods_cnt != 1)
 838                 return NULL;
 839
 840         return omap_hwmod_get_mpu_rt_va(od->hwmods[0]);
 841 }
 842
 843 /*
 844  * Public functions intended for use in omap_device_pm_latency
 845  * .activate_func and .deactivate_func function pointers
 846  */
 847
 848 /**
 849  * omap_device_enable_hwmods - call omap_hwmod_enable() on all hwmods
 850  * @od: struct omap_device *od
 851  *
 852  * Enable all underlying hwmods.  Returns 0.
 853  */
 854 int omap_device_enable_hwmods(struct omap_device *od)
 855 {
 856         int i;
 857
 858         for (i = 0; i < od->hwmods_cnt; i++)
 859                 omap_hwmod_enable(od->hwmods[i]);
 860
 861         /* XXX pass along return value here? */
 862         return 0;
 863 }
 864
 865 /**
 866  * omap_device_idle_hwmods - call omap_hwmod_idle() on all hwmods
 867  * @od: struct omap_device *od
 868  *
 869  * Idle all underlying hwmods.  Returns 0.
 870  */
 871 int omap_device_idle_hwmods(struct omap_device *od)
 872 {
 873         int i;
 874
 875         for (i = 0; i < od->hwmods_cnt; i++)
 876                 omap_hwmod_idle(od->hwmods[i]);
 877
 878         /* XXX pass along return value here? */
 879         return 0;
 880 }
 881
 882 /**
 883  * omap_device_disable_clocks - disable all main and interface clocks
 884  * @od: struct omap_device *od
 885  *
 886  * Disable the main functional clock and interface clock for all of the
 887  * omap_hwmods associated with the omap_device.  Returns 0.
 888  */
 889 int omap_device_disable_clocks(struct omap_device *od)
 890 {
 891         int i;
 892
 893         for (i = 0; i < od->hwmods_cnt; i++)
 894                 omap_hwmod_disable_clocks(od->hwmods[i]);
 895
 896         /* XXX pass along return value here? */
 897         return 0;
 898 }
 899
 900 /**
 901  * omap_device_enable_clocks - enable all main and interface clocks
 902  * @od: struct omap_device *od
 903  *
 904  * Enable the main functional clock and interface clock for all of the
 905  * omap_hwmods associated with the omap_device.  Returns 0.
 906  */
 907 int omap_device_enable_clocks(struct omap_device *od)
 908 {
 909         int i;
 910
 911         for (i = 0; i < od->hwmods_cnt; i++)
 912                 omap_hwmod_enable_clocks(od->hwmods[i]);
 913
 914         /* XXX pass along return value here? */
 915         return 0;
 916 }
 917
 918 struct device omap_device_parent = {
 919         .init_name      = "omap",
 920         .parent         = &platform_bus,
 921 };
 922
 923 static int __init omap_device_init(void)
 924 {
 925         return device_register(&omap_device_parent);
 926 }
 927 core_initcall(omap_device_init);