drivers/amba/bus.c

   1 /*
   2  *  linux/arch/arm/common/amba.c
   3  *
   4  *  Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/device.h>
  13 #include <linux/string.h>
  14 #include <linux/slab.h>
  15 #include <linux/io.h>
  16 #include <linux/pm.h>
  17 #include <linux/pm_runtime.h>
  18 #include <linux/amba/bus.h>
  19
  20 #include <asm/irq.h>
  21 #include <asm/sizes.h>
  22
  23 #define to_amba_driver(d)       container_of(d, struct amba_driver, drv)
  24
  25 static const struct amba_id *
  26 amba_lookup(const struct amba_id *table, struct amba_device *dev)
  27 {
  28         int ret = 0;
  29
  30         while (table->mask) {
  31                 ret = (dev->periphid & table->mask) == table->id;
  32                 if (ret)
  33                         break;
  34                 table++;
  35         }
  36
  37         return ret ? table : NULL;
  38 }
  39
  40 static int amba_match(struct device *dev, struct device_driver *drv)
  41 {
  42         struct amba_device *pcdev = to_amba_device(dev);
  43         struct amba_driver *pcdrv = to_amba_driver(drv);
  44
  45         return amba_lookup(pcdrv->id_table, pcdev) != NULL;
  46 }
  47
  48 #ifdef CONFIG_HOTPLUG
  49 static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
  50 {
  51         struct amba_device *pcdev = to_amba_device(dev);
  52         int retval = 0;
  53
  54         retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
  55         if (retval)
  56                 return retval;
  57
  58         retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
  59         return retval;
  60 }
  61 #else
  62 #define amba_uevent NULL
  63 #endif
  64
  65 #define amba_attr_func(name,fmt,arg...)                                 \
  66 static ssize_t name##_show(struct device *_dev,                         \
  67                            struct device_attribute *attr, char *buf)    \
  68 {                                                                       \
  69         struct amba_device *dev = to_amba_device(_dev);                 \
  70         return sprintf(buf, fmt, arg);                                  \
  71 }
  72
  73 #define amba_attr(name,fmt,arg...)      \
  74 amba_attr_func(name,fmt,arg)            \
  75 static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
  76
  77 amba_attr_func(id, "%08x\n", dev->periphid);
  78 amba_attr(irq0, "%u\n", dev->irq[0]);
  79 amba_attr(irq1, "%u\n", dev->irq[1]);
  80 amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
  81          (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
  82          dev->res.flags);
  83
  84 static struct device_attribute amba_dev_attrs[] = {
  85         __ATTR_RO(id),
  86         __ATTR_RO(resource),
  87         __ATTR_NULL,
  88 };
  89
  90 #ifdef CONFIG_PM_SLEEP
  91
  92 static int amba_legacy_suspend(struct device *dev, pm_message_t mesg)
  93 {
  94         struct amba_driver *adrv = to_amba_driver(dev->driver);
  95         struct amba_device *adev = to_amba_device(dev);
  96         int ret = 0;
  97
  98         if (dev->driver && adrv->suspend)
  99                 ret = adrv->suspend(adev, mesg);
 100
 101         return ret;
 102 }
 103
 104 static int amba_legacy_resume(struct device *dev)
 105 {
 106         struct amba_driver *adrv = to_amba_driver(dev->driver);
 107         struct amba_device *adev = to_amba_device(dev);
 108         int ret = 0;
 109
 110         if (dev->driver && adrv->resume)
 111                 ret = adrv->resume(adev);
 112
 113         return ret;
 114 }
 115
 116 #endif /* CONFIG_PM_SLEEP */
 117
 118 #ifdef CONFIG_SUSPEND
 119
 120 static int amba_pm_suspend(struct device *dev)
 121 {
 122         struct device_driver *drv = dev->driver;
 123         int ret = 0;
 124
 125         if (!drv)
 126                 return 0;
 127
 128         if (drv->pm) {
 129                 if (drv->pm->suspend)
 130                         ret = drv->pm->suspend(dev);
 131         } else {
 132                 ret = amba_legacy_suspend(dev, PMSG_SUSPEND);
 133         }
 134
 135         return ret;
 136 }
 137
 138 static int amba_pm_resume(struct device *dev)
 139 {
 140         struct device_driver *drv = dev->driver;
 141         int ret = 0;
 142
 143         if (!drv)
 144                 return 0;
 145
 146         if (drv->pm) {
 147                 if (drv->pm->resume)
 148                         ret = drv->pm->resume(dev);
 149         } else {
 150                 ret = amba_legacy_resume(dev);
 151         }
 152
 153         return ret;
 154 }
 155
 156 #else /* !CONFIG_SUSPEND */
 157
 158 #define amba_pm_suspend         NULL
 159 #define amba_pm_resume          NULL
 160
 161 #endif /* !CONFIG_SUSPEND */
 162
 163 #ifdef CONFIG_HIBERNATE_CALLBACKS
 164
 165 static int amba_pm_freeze(struct device *dev)
 166 {
 167         struct device_driver *drv = dev->driver;
 168         int ret = 0;
 169
 170         if (!drv)
 171                 return 0;
 172
 173         if (drv->pm) {
 174                 if (drv->pm->freeze)
 175                         ret = drv->pm->freeze(dev);
 176         } else {
 177                 ret = amba_legacy_suspend(dev, PMSG_FREEZE);
 178         }
 179
 180         return ret;
 181 }
 182
 183 static int amba_pm_thaw(struct device *dev)
 184 {
 185         struct device_driver *drv = dev->driver;
 186         int ret = 0;
 187
 188         if (!drv)
 189                 return 0;
 190
 191         if (drv->pm) {
 192                 if (drv->pm->thaw)
 193                         ret = drv->pm->thaw(dev);
 194         } else {
 195                 ret = amba_legacy_resume(dev);
 196         }
 197
 198         return ret;
 199 }
 200
 201 static int amba_pm_poweroff(struct device *dev)
 202 {
 203         struct device_driver *drv = dev->driver;
 204         int ret = 0;
 205
 206         if (!drv)
 207                 return 0;
 208
 209         if (drv->pm) {
 210                 if (drv->pm->poweroff)
 211                         ret = drv->pm->poweroff(dev);
 212         } else {
 213                 ret = amba_legacy_suspend(dev, PMSG_HIBERNATE);
 214         }
 215
 216         return ret;
 217 }
 218
 219 static int amba_pm_restore(struct device *dev)
 220 {
 221         struct device_driver *drv = dev->driver;
 222         int ret = 0;
 223
 224         if (!drv)
 225                 return 0;
 226
 227         if (drv->pm) {
 228                 if (drv->pm->restore)
 229                         ret = drv->pm->restore(dev);
 230         } else {
 231                 ret = amba_legacy_resume(dev);
 232         }
 233
 234         return ret;
 235 }
 236
 237 #else /* !CONFIG_HIBERNATE_CALLBACKS */
 238
 239 #define amba_pm_freeze          NULL
 240 #define amba_pm_thaw            NULL
 241 #define amba_pm_poweroff                NULL
 242 #define amba_pm_restore         NULL
 243
 244 #endif /* !CONFIG_HIBERNATE_CALLBACKS */
 245
 246 #ifdef CONFIG_PM_RUNTIME
 247 /*
 248  * Hooks to provide runtime PM of the pclk (bus clock).  It is safe to
 249  * enable/disable the bus clock at runtime PM suspend/resume as this
 250  * does not result in loss of context.  However, disabling vcore power
 251  * would do, so we leave that to the driver.
 252  */
 253 static int amba_pm_runtime_suspend(struct device *dev)
 254 {
 255         struct amba_device *pcdev = to_amba_device(dev);
 256         int ret = pm_generic_runtime_suspend(dev);
 257
 258         if (ret == 0 && dev->driver)
 259                 clk_disable(pcdev->pclk);
 260
 261         return ret;
 262 }
 263
 264 static int amba_pm_runtime_resume(struct device *dev)
 265 {
 266         struct amba_device *pcdev = to_amba_device(dev);
 267         int ret;
 268
 269         if (dev->driver) {
 270                 ret = clk_enable(pcdev->pclk);
 271                 /* Failure is probably fatal to the system, but... */
 272                 if (ret)
 273                         return ret;
 274         }
 275
 276         return pm_generic_runtime_resume(dev);
 277 }
 278 #endif
 279
 280 #ifdef CONFIG_PM
 281
 282 static const struct dev_pm_ops amba_pm = {
 283         .suspend        = amba_pm_suspend,
 284         .resume         = amba_pm_resume,
 285         .freeze         = amba_pm_freeze,
 286         .thaw           = amba_pm_thaw,
 287         .poweroff       = amba_pm_poweroff,
 288         .restore        = amba_pm_restore,
 289         SET_RUNTIME_PM_OPS(
 290                 amba_pm_runtime_suspend,
 291                 amba_pm_runtime_resume,
 292                 pm_generic_runtime_idle
 293         )
 294 };
 295
 296 #define AMBA_PM (&amba_pm)
 297
 298 #else /* !CONFIG_PM */
 299
 300 #define AMBA_PM NULL
 301
 302 #endif /* !CONFIG_PM */
 303
 304 /*
 305  * Primecells are part of the Advanced Microcontroller Bus Architecture,
 306  * so we call the bus "amba".
 307  */
 308 struct bus_type amba_bustype = {
 309         .name           = "amba",
 310         .dev_attrs      = amba_dev_attrs,
 311         .match          = amba_match,
 312         .uevent         = amba_uevent,
 313         .pm             = AMBA_PM,
 314 };
 315
 316 static int __init amba_init(void)
 317 {
 318         return bus_register(&amba_bustype);
 319 }
 320
 321 postcore_initcall(amba_init);
 322
 323 static int amba_get_enable_pclk(struct amba_device *pcdev)
 324 {
 325         struct clk *pclk = clk_get(&pcdev->dev, "apb_pclk");
 326         int ret;
 327
 328         pcdev->pclk = pclk;
 329
 330         if (IS_ERR(pclk))
 331                 return PTR_ERR(pclk);
 332
 333         ret = clk_prepare(pclk);
 334         if (ret) {
 335                 clk_put(pclk);
 336                 return ret;
 337         }
 338
 339         ret = clk_enable(pclk);
 340         if (ret) {
 341                 clk_unprepare(pclk);
 342                 clk_put(pclk);
 343         }
 344
 345         return ret;
 346 }
 347
 348 static void amba_put_disable_pclk(struct amba_device *pcdev)
 349 {
 350         struct clk *pclk = pcdev->pclk;
 351
 352         clk_disable(pclk);
 353         clk_unprepare(pclk);
 354         clk_put(pclk);
 355 }
 356
 357 static int amba_get_enable_vcore(struct amba_device *pcdev)
 358 {
 359         struct regulator *vcore = regulator_get(&pcdev->dev, "vcore");
 360         int ret;
 361
 362         pcdev->vcore = vcore;
 363
 364         if (IS_ERR(vcore)) {
 365                 /* It is OK not to supply a vcore regulator */
 366                 if (PTR_ERR(vcore) == -ENODEV)
 367                         return 0;
 368                 return PTR_ERR(vcore);
 369         }
 370
 371         ret = regulator_enable(vcore);
 372         if (ret) {
 373                 regulator_put(vcore);
 374                 pcdev->vcore = ERR_PTR(-ENODEV);
 375         }
 376
 377         return ret;
 378 }
 379
 380 static void amba_put_disable_vcore(struct amba_device *pcdev)
 381 {
 382         struct regulator *vcore = pcdev->vcore;
 383
 384         if (!IS_ERR(vcore)) {
 385                 regulator_disable(vcore);
 386                 regulator_put(vcore);
 387         }
 388 }
 389
 390 /*
 391  * These are the device model conversion veneers; they convert the
 392  * device model structures to our more specific structures.
 393  */
 394 static int amba_probe(struct device *dev)
 395 {
 396         struct amba_device *pcdev = to_amba_device(dev);
 397         struct amba_driver *pcdrv = to_amba_driver(dev->driver);
 398         const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
 399         int ret;
 400
 401         do {
 402                 ret = amba_get_enable_vcore(pcdev);
 403                 if (ret)
 404                         break;
 405
 406                 ret = amba_get_enable_pclk(pcdev);
 407                 if (ret)
 408                         break;
 409
 410                 pm_runtime_get_noresume(dev);
 411                 pm_runtime_set_active(dev);
 412                 pm_runtime_enable(dev);
 413
 414                 ret = pcdrv->probe(pcdev, id);
 415                 if (ret == 0)
 416                         break;
 417
 418                 pm_runtime_disable(dev);
 419                 pm_runtime_set_suspended(dev);
 420                 pm_runtime_put_noidle(dev);
 421
 422                 amba_put_disable_pclk(pcdev);
 423                 amba_put_disable_vcore(pcdev);
 424         } while (0);
 425
 426         return ret;
 427 }
 428
 429 static int amba_remove(struct device *dev)
 430 {
 431         struct amba_device *pcdev = to_amba_device(dev);
 432         struct amba_driver *drv = to_amba_driver(dev->driver);
 433         int ret;
 434
 435         pm_runtime_get_sync(dev);
 436         ret = drv->remove(pcdev);
 437         pm_runtime_put_noidle(dev);
 438
 439         /* Undo the runtime PM settings in amba_probe() */
 440         pm_runtime_disable(dev);
 441         pm_runtime_set_suspended(dev);
 442         pm_runtime_put_noidle(dev);
 443
 444         amba_put_disable_pclk(pcdev);
 445         amba_put_disable_vcore(pcdev);
 446
 447         return ret;
 448 }
 449
 450 static void amba_shutdown(struct device *dev)
 451 {
 452         struct amba_driver *drv = to_amba_driver(dev->driver);
 453         drv->shutdown(to_amba_device(dev));
 454 }
 455
 456 /**
 457  *      amba_driver_register - register an AMBA device driver
 458  *      @drv: amba device driver structure
 459  *
 460  *      Register an AMBA device driver with the Linux device model
 461  *      core.  If devices pre-exist, the drivers probe function will
 462  *      be called.
 463  */
 464 int amba_driver_register(struct amba_driver *drv)
 465 {
 466         drv->drv.bus = &amba_bustype;
 467
 468 #define SETFN(fn)       if (drv->fn) drv->drv.fn = amba_##fn
 469         SETFN(probe);
 470         SETFN(remove);
 471         SETFN(shutdown);
 472
 473         return driver_register(&drv->drv);
 474 }
 475
 476 /**
 477  *      amba_driver_unregister - remove an AMBA device driver
 478  *      @drv: AMBA device driver structure to remove
 479  *
 480  *      Unregister an AMBA device driver from the Linux device
 481  *      model.  The device model will call the drivers remove function
 482  *      for each device the device driver is currently handling.
 483  */
 484 void amba_driver_unregister(struct amba_driver *drv)
 485 {
 486         driver_unregister(&drv->drv);
 487 }
 488
 489
 490 static void amba_device_release(struct device *dev)
 491 {
 492         struct amba_device *d = to_amba_device(dev);
 493
 494         if (d->res.parent)
 495                 release_resource(&d->res);
 496         kfree(d);
 497 }
 498
 499 /**
 500  *      amba_device_register - register an AMBA device
 501  *      @dev: AMBA device to register
 502  *      @parent: parent memory resource
 503  *
 504  *      Setup the AMBA device, reading the cell ID if present.
 505  *      Claim the resource, and register the AMBA device with
 506  *      the Linux device manager.
 507  */
 508 int amba_device_register(struct amba_device *dev, struct resource *parent)
 509 {
 510         u32 size;
 511         void __iomem *tmp;
 512         int i, ret;
 513
 514         device_initialize(&dev->dev);
 515
 516         /*
 517          * Copy from device_add
 518          */
 519         if (dev->dev.init_name) {
 520                 dev_set_name(&dev->dev, "%s", dev->dev.init_name);
 521                 dev->dev.init_name = NULL;
 522         }
 523
 524         dev->dev.release = amba_device_release;
 525         dev->dev.bus = &amba_bustype;
 526         dev->dev.dma_mask = &dev->dma_mask;
 527         dev->res.name = dev_name(&dev->dev);
 528
 529         if (!dev->dev.coherent_dma_mask && dev->dma_mask)
 530                 dev_warn(&dev->dev, "coherent dma mask is unset\n");
 531
 532         ret = request_resource(parent, &dev->res);
 533         if (ret)
 534                 goto err_out;
 535
 536         /* Hard-coded primecell ID instead of plug-n-play */
 537         if (dev->periphid != 0)
 538                 goto skip_probe;
 539
 540         /*
 541          * Dynamically calculate the size of the resource
 542          * and use this for iomap
 543          */
 544         size = resource_size(&dev->res);
 545         tmp = ioremap(dev->res.start, size);
 546         if (!tmp) {
 547                 ret = -ENOMEM;
 548                 goto err_release;
 549         }
 550
 551         ret = amba_get_enable_pclk(dev);
 552         if (ret == 0) {
 553                 u32 pid, cid;
 554
 555                 /*
 556                  * Read pid and cid based on size of resource
 557                  * they are located at end of region
 558                  */
 559                 for (pid = 0, i = 0; i < 4; i++)
 560                         pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) <<
 561                                 (i * 8);
 562                 for (cid = 0, i = 0; i < 4; i++)
 563                         cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
 564                                 (i * 8);
 565
 566                 amba_put_disable_pclk(dev);
 567
 568                 if (cid == AMBA_CID)
 569                         dev->periphid = pid;
 570
 571                 if (!dev->periphid)
 572                         ret = -ENODEV;
 573         }
 574
 575         iounmap(tmp);
 576
 577         if (ret)
 578                 goto err_release;
 579
 580  skip_probe:
 581         ret = device_add(&dev->dev);
 582         if (ret)
 583                 goto err_release;
 584
 585         if (dev->irq[0] != NO_IRQ)
 586                 ret = device_create_file(&dev->dev, &dev_attr_irq0);
 587         if (ret == 0 && dev->irq[1] != NO_IRQ)
 588                 ret = device_create_file(&dev->dev, &dev_attr_irq1);
 589         if (ret == 0)
 590                 return ret;
 591
 592         device_unregister(&dev->dev);
 593
 594  err_release:
 595         release_resource(&dev->res);
 596  err_out:
 597         return ret;
 598 }
 599
 600 /**
 601  *      amba_device_unregister - unregister an AMBA device
 602  *      @dev: AMBA device to remove
 603  *
 604  *      Remove the specified AMBA device from the Linux device
 605  *      manager.  All files associated with this object will be
 606  *      destroyed, and device drivers notified that the device has
 607  *      been removed.  The AMBA device's resources including
 608  *      the amba_device structure will be freed once all
 609  *      references to it have been dropped.
 610  */
 611 void amba_device_unregister(struct amba_device *dev)
 612 {
 613         device_unregister(&dev->dev);
 614 }
 615
 616
 617 struct find_data {
 618         struct amba_device *dev;
 619         struct device *parent;
 620         const char *busid;
 621         unsigned int id;
 622         unsigned int mask;
 623 };
 624
 625 static int amba_find_match(struct device *dev, void *data)
 626 {
 627         struct find_data *d = data;
 628         struct amba_device *pcdev = to_amba_device(dev);
 629         int r;
 630
 631         r = (pcdev->periphid & d->mask) == d->id;
 632         if (d->parent)
 633                 r &= d->parent == dev->parent;
 634         if (d->busid)
 635                 r &= strcmp(dev_name(dev), d->busid) == 0;
 636
 637         if (r) {
 638                 get_device(dev);
 639                 d->dev = pcdev;
 640         }
 641
 642         return r;
 643 }
 644
 645 /**
 646  *      amba_find_device - locate an AMBA device given a bus id
 647  *      @busid: bus id for device (or NULL)
 648  *      @parent: parent device (or NULL)
 649  *      @id: peripheral ID (or 0)
 650  *      @mask: peripheral ID mask (or 0)
 651  *
 652  *      Return the AMBA device corresponding to the supplied parameters.
 653  *      If no device matches, returns NULL.
 654  *
 655  *      NOTE: When a valid device is found, its refcount is
 656  *      incremented, and must be decremented before the returned
 657  *      reference.
 658  */
 659 struct amba_device *
 660 amba_find_device(const char *busid, struct device *parent, unsigned int id,
 661                  unsigned int mask)
 662 {
 663         struct find_data data;
 664
 665         data.dev = NULL;
 666         data.parent = parent;
 667         data.busid = busid;
 668         data.id = id;
 669         data.mask = mask;
 670
 671         bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
 672
 673         return data.dev;
 674 }
 675
 676 /**
 677  *      amba_request_regions - request all mem regions associated with device
 678  *      @dev: amba_device structure for device
 679  *      @name: name, or NULL to use driver name
 680  */
 681 int amba_request_regions(struct amba_device *dev, const char *name)
 682 {
 683         int ret = 0;
 684         u32 size;
 685
 686         if (!name)
 687                 name = dev->dev.driver->name;
 688
 689         size = resource_size(&dev->res);
 690
 691         if (!request_mem_region(dev->res.start, size, name))
 692                 ret = -EBUSY;
 693
 694         return ret;
 695 }
 696
 697 /**
 698  *      amba_release_regions - release mem regions associated with device
 699  *      @dev: amba_device structure for device
 700  *
 701  *      Release regions claimed by a successful call to amba_request_regions.
 702  */
 703 void amba_release_regions(struct amba_device *dev)
 704 {
 705         u32 size;
 706
 707         size = resource_size(&dev->res);
 708         release_mem_region(dev->res.start, size);
 709 }
 710
 711 EXPORT_SYMBOL(amba_driver_register);
 712 EXPORT_SYMBOL(amba_driver_unregister);
 713 EXPORT_SYMBOL(amba_device_register);
 714 EXPORT_SYMBOL(amba_device_unregister);
 715 EXPORT_SYMBOL(amba_find_device);
 716 EXPORT_SYMBOL(amba_request_regions);
 717 EXPORT_SYMBOL(amba_release_regions);