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         return retval;
  56 }
  57 #else
  58 #define amba_uevent NULL
  59 #endif
  60
  61 #define amba_attr_func(name,fmt,arg...)                                 \
  62 static ssize_t name##_show(struct device *_dev,                         \
  63                            struct device_attribute *attr, char *buf)    \
  64 {                                                                       \
  65         struct amba_device *dev = to_amba_device(_dev);                 \
  66         return sprintf(buf, fmt, arg);                                  \
  67 }
  68
  69 #define amba_attr(name,fmt,arg...)      \
  70 amba_attr_func(name,fmt,arg)            \
  71 static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
  72
  73 amba_attr_func(id, "%08x\n", dev->periphid);
  74 amba_attr(irq0, "%u\n", dev->irq[0]);
  75 amba_attr(irq1, "%u\n", dev->irq[1]);
  76 amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
  77          (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
  78          dev->res.flags);
  79
  80 static struct device_attribute amba_dev_attrs[] = {
  81         __ATTR_RO(id),
  82         __ATTR_RO(resource),
  83         __ATTR_NULL,
  84 };
  85
  86 #ifdef CONFIG_PM_SLEEP
  87
  88 static int amba_legacy_suspend(struct device *dev, pm_message_t mesg)
  89 {
  90         struct amba_driver *adrv = to_amba_driver(dev->driver);
  91         struct amba_device *adev = to_amba_device(dev);
  92         int ret = 0;
  93
  94         if (dev->driver && adrv->suspend)
  95                 ret = adrv->suspend(adev, mesg);
  96
  97         return ret;
  98 }
  99
 100 static int amba_legacy_resume(struct device *dev)
 101 {
 102         struct amba_driver *adrv = to_amba_driver(dev->driver);
 103         struct amba_device *adev = to_amba_device(dev);
 104         int ret = 0;
 105
 106         if (dev->driver && adrv->resume)
 107                 ret = adrv->resume(adev);
 108
 109         return ret;
 110 }
 111
 112 static int amba_pm_prepare(struct device *dev)
 113 {
 114         struct device_driver *drv = dev->driver;
 115         int ret = 0;
 116
 117         if (drv && drv->pm && drv->pm->prepare)
 118                 ret = drv->pm->prepare(dev);
 119
 120         return ret;
 121 }
 122
 123 static void amba_pm_complete(struct device *dev)
 124 {
 125         struct device_driver *drv = dev->driver;
 126
 127         if (drv && drv->pm && drv->pm->complete)
 128                 drv->pm->complete(dev);
 129 }
 130
 131 #else /* !CONFIG_PM_SLEEP */
 132
 133 #define amba_pm_prepare         NULL
 134 #define amba_pm_complete                NULL
 135
 136 #endif /* !CONFIG_PM_SLEEP */
 137
 138 #ifdef CONFIG_SUSPEND
 139
 140 static int amba_pm_suspend(struct device *dev)
 141 {
 142         struct device_driver *drv = dev->driver;
 143         int ret = 0;
 144
 145         if (!drv)
 146                 return 0;
 147
 148         if (drv->pm) {
 149                 if (drv->pm->suspend)
 150                         ret = drv->pm->suspend(dev);
 151         } else {
 152                 ret = amba_legacy_suspend(dev, PMSG_SUSPEND);
 153         }
 154
 155         return ret;
 156 }
 157
 158 static int amba_pm_suspend_noirq(struct device *dev)
 159 {
 160         struct device_driver *drv = dev->driver;
 161         int ret = 0;
 162
 163         if (!drv)
 164                 return 0;
 165
 166         if (drv->pm) {
 167                 if (drv->pm->suspend_noirq)
 168                         ret = drv->pm->suspend_noirq(dev);
 169         }
 170
 171         return ret;
 172 }
 173
 174 static int amba_pm_resume(struct device *dev)
 175 {
 176         struct device_driver *drv = dev->driver;
 177         int ret = 0;
 178
 179         if (!drv)
 180                 return 0;
 181
 182         if (drv->pm) {
 183                 if (drv->pm->resume)
 184                         ret = drv->pm->resume(dev);
 185         } else {
 186                 ret = amba_legacy_resume(dev);
 187         }
 188
 189         return ret;
 190 }
 191
 192 static int amba_pm_resume_noirq(struct device *dev)
 193 {
 194         struct device_driver *drv = dev->driver;
 195         int ret = 0;
 196
 197         if (!drv)
 198                 return 0;
 199
 200         if (drv->pm) {
 201                 if (drv->pm->resume_noirq)
 202                         ret = drv->pm->resume_noirq(dev);
 203         }
 204
 205         return ret;
 206 }
 207
 208 #else /* !CONFIG_SUSPEND */
 209
 210 #define amba_pm_suspend         NULL
 211 #define amba_pm_resume          NULL
 212 #define amba_pm_suspend_noirq   NULL
 213 #define amba_pm_resume_noirq    NULL
 214
 215 #endif /* !CONFIG_SUSPEND */
 216
 217 #ifdef CONFIG_HIBERNATE_CALLBACKS
 218
 219 static int amba_pm_freeze(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->freeze)
 229                         ret = drv->pm->freeze(dev);
 230         } else {
 231                 ret = amba_legacy_suspend(dev, PMSG_FREEZE);
 232         }
 233
 234         return ret;
 235 }
 236
 237 static int amba_pm_freeze_noirq(struct device *dev)
 238 {
 239         struct device_driver *drv = dev->driver;
 240         int ret = 0;
 241
 242         if (!drv)
 243                 return 0;
 244
 245         if (drv->pm) {
 246                 if (drv->pm->freeze_noirq)
 247                         ret = drv->pm->freeze_noirq(dev);
 248         }
 249
 250         return ret;
 251 }
 252
 253 static int amba_pm_thaw(struct device *dev)
 254 {
 255         struct device_driver *drv = dev->driver;
 256         int ret = 0;
 257
 258         if (!drv)
 259                 return 0;
 260
 261         if (drv->pm) {
 262                 if (drv->pm->thaw)
 263                         ret = drv->pm->thaw(dev);
 264         } else {
 265                 ret = amba_legacy_resume(dev);
 266         }
 267
 268         return ret;
 269 }
 270
 271 static int amba_pm_thaw_noirq(struct device *dev)
 272 {
 273         struct device_driver *drv = dev->driver;
 274         int ret = 0;
 275
 276         if (!drv)
 277                 return 0;
 278
 279         if (drv->pm) {
 280                 if (drv->pm->thaw_noirq)
 281                         ret = drv->pm->thaw_noirq(dev);
 282         }
 283
 284         return ret;
 285 }
 286
 287 static int amba_pm_poweroff(struct device *dev)
 288 {
 289         struct device_driver *drv = dev->driver;
 290         int ret = 0;
 291
 292         if (!drv)
 293                 return 0;
 294
 295         if (drv->pm) {
 296                 if (drv->pm->poweroff)
 297                         ret = drv->pm->poweroff(dev);
 298         } else {
 299                 ret = amba_legacy_suspend(dev, PMSG_HIBERNATE);
 300         }
 301
 302         return ret;
 303 }
 304
 305 static int amba_pm_poweroff_noirq(struct device *dev)
 306 {
 307         struct device_driver *drv = dev->driver;
 308         int ret = 0;
 309
 310         if (!drv)
 311                 return 0;
 312
 313         if (drv->pm) {
 314                 if (drv->pm->poweroff_noirq)
 315                         ret = drv->pm->poweroff_noirq(dev);
 316         }
 317
 318         return ret;
 319 }
 320
 321 static int amba_pm_restore(struct device *dev)
 322 {
 323         struct device_driver *drv = dev->driver;
 324         int ret = 0;
 325
 326         if (!drv)
 327                 return 0;
 328
 329         if (drv->pm) {
 330                 if (drv->pm->restore)
 331                         ret = drv->pm->restore(dev);
 332         } else {
 333                 ret = amba_legacy_resume(dev);
 334         }
 335
 336         return ret;
 337 }
 338
 339 static int amba_pm_restore_noirq(struct device *dev)
 340 {
 341         struct device_driver *drv = dev->driver;
 342         int ret = 0;
 343
 344         if (!drv)
 345                 return 0;
 346
 347         if (drv->pm) {
 348                 if (drv->pm->restore_noirq)
 349                         ret = drv->pm->restore_noirq(dev);
 350         }
 351
 352         return ret;
 353 }
 354
 355 #else /* !CONFIG_HIBERNATE_CALLBACKS */
 356
 357 #define amba_pm_freeze          NULL
 358 #define amba_pm_thaw            NULL
 359 #define amba_pm_poweroff                NULL
 360 #define amba_pm_restore         NULL
 361 #define amba_pm_freeze_noirq    NULL
 362 #define amba_pm_thaw_noirq              NULL
 363 #define amba_pm_poweroff_noirq  NULL
 364 #define amba_pm_restore_noirq   NULL
 365
 366 #endif /* !CONFIG_HIBERNATE_CALLBACKS */
 367
 368 #ifdef CONFIG_PM
 369
 370 static const struct dev_pm_ops amba_pm = {
 371         .prepare        = amba_pm_prepare,
 372         .complete       = amba_pm_complete,
 373         .suspend        = amba_pm_suspend,
 374         .resume         = amba_pm_resume,
 375         .freeze         = amba_pm_freeze,
 376         .thaw           = amba_pm_thaw,
 377         .poweroff       = amba_pm_poweroff,
 378         .restore        = amba_pm_restore,
 379         .suspend_noirq  = amba_pm_suspend_noirq,
 380         .resume_noirq   = amba_pm_resume_noirq,
 381         .freeze_noirq   = amba_pm_freeze_noirq,
 382         .thaw_noirq     = amba_pm_thaw_noirq,
 383         .poweroff_noirq = amba_pm_poweroff_noirq,
 384         .restore_noirq  = amba_pm_restore_noirq,
 385         SET_RUNTIME_PM_OPS(
 386                 pm_generic_runtime_suspend,
 387                 pm_generic_runtime_resume,
 388                 pm_generic_runtime_idle
 389         )
 390 };
 391
 392 #define AMBA_PM (&amba_pm)
 393
 394 #else /* !CONFIG_PM */
 395
 396 #define AMBA_PM NULL
 397
 398 #endif /* !CONFIG_PM */
 399
 400 /*
 401  * Primecells are part of the Advanced Microcontroller Bus Architecture,
 402  * so we call the bus "amba".
 403  */
 404 struct bus_type amba_bustype = {
 405         .name           = "amba",
 406         .dev_attrs      = amba_dev_attrs,
 407         .match          = amba_match,
 408         .uevent         = amba_uevent,
 409         .pm             = AMBA_PM,
 410 };
 411
 412 static int __init amba_init(void)
 413 {
 414         return bus_register(&amba_bustype);
 415 }
 416
 417 postcore_initcall(amba_init);
 418
 419 static int amba_get_enable_pclk(struct amba_device *pcdev)
 420 {
 421         struct clk *pclk = clk_get(&pcdev->dev, "apb_pclk");
 422         int ret;
 423
 424         pcdev->pclk = pclk;
 425
 426         if (IS_ERR(pclk))
 427                 return PTR_ERR(pclk);
 428
 429         ret = clk_enable(pclk);
 430         if (ret)
 431                 clk_put(pclk);
 432
 433         return ret;
 434 }
 435
 436 static void amba_put_disable_pclk(struct amba_device *pcdev)
 437 {
 438         struct clk *pclk = pcdev->pclk;
 439
 440         clk_disable(pclk);
 441         clk_put(pclk);
 442 }
 443
 444 static int amba_get_enable_vcore(struct amba_device *pcdev)
 445 {
 446         struct regulator *vcore = regulator_get(&pcdev->dev, "vcore");
 447         int ret;
 448
 449         pcdev->vcore = vcore;
 450
 451         if (IS_ERR(vcore)) {
 452                 /* It is OK not to supply a vcore regulator */
 453                 if (PTR_ERR(vcore) == -ENODEV)
 454                         return 0;
 455                 return PTR_ERR(vcore);
 456         }
 457
 458         ret = regulator_enable(vcore);
 459         if (ret) {
 460                 regulator_put(vcore);
 461                 pcdev->vcore = ERR_PTR(-ENODEV);
 462         }
 463
 464         return ret;
 465 }
 466
 467 static void amba_put_disable_vcore(struct amba_device *pcdev)
 468 {
 469         struct regulator *vcore = pcdev->vcore;
 470
 471         if (!IS_ERR(vcore)) {
 472                 regulator_disable(vcore);
 473                 regulator_put(vcore);
 474         }
 475 }
 476
 477 /*
 478  * These are the device model conversion veneers; they convert the
 479  * device model structures to our more specific structures.
 480  */
 481 static int amba_probe(struct device *dev)
 482 {
 483         struct amba_device *pcdev = to_amba_device(dev);
 484         struct amba_driver *pcdrv = to_amba_driver(dev->driver);
 485         const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
 486         int ret;
 487
 488         do {
 489                 ret = amba_get_enable_vcore(pcdev);
 490                 if (ret)
 491                         break;
 492
 493                 ret = amba_get_enable_pclk(pcdev);
 494                 if (ret)
 495                         break;
 496
 497                 ret = pcdrv->probe(pcdev, id);
 498                 if (ret == 0)
 499                         break;
 500
 501                 amba_put_disable_pclk(pcdev);
 502                 amba_put_disable_vcore(pcdev);
 503         } while (0);
 504
 505         return ret;
 506 }
 507
 508 static int amba_remove(struct device *dev)
 509 {
 510         struct amba_device *pcdev = to_amba_device(dev);
 511         struct amba_driver *drv = to_amba_driver(dev->driver);
 512         int ret = drv->remove(pcdev);
 513
 514         amba_put_disable_pclk(pcdev);
 515         amba_put_disable_vcore(pcdev);
 516
 517         return ret;
 518 }
 519
 520 static void amba_shutdown(struct device *dev)
 521 {
 522         struct amba_driver *drv = to_amba_driver(dev->driver);
 523         drv->shutdown(to_amba_device(dev));
 524 }
 525
 526 /**
 527  *      amba_driver_register - register an AMBA device driver
 528  *      @drv: amba device driver structure
 529  *
 530  *      Register an AMBA device driver with the Linux device model
 531  *      core.  If devices pre-exist, the drivers probe function will
 532  *      be called.
 533  */
 534 int amba_driver_register(struct amba_driver *drv)
 535 {
 536         drv->drv.bus = &amba_bustype;
 537
 538 #define SETFN(fn)       if (drv->fn) drv->drv.fn = amba_##fn
 539         SETFN(probe);
 540         SETFN(remove);
 541         SETFN(shutdown);
 542
 543         return driver_register(&drv->drv);
 544 }
 545
 546 /**
 547  *      amba_driver_unregister - remove an AMBA device driver
 548  *      @drv: AMBA device driver structure to remove
 549  *
 550  *      Unregister an AMBA device driver from the Linux device
 551  *      model.  The device model will call the drivers remove function
 552  *      for each device the device driver is currently handling.
 553  */
 554 void amba_driver_unregister(struct amba_driver *drv)
 555 {
 556         driver_unregister(&drv->drv);
 557 }
 558
 559
 560 static void amba_device_release(struct device *dev)
 561 {
 562         struct amba_device *d = to_amba_device(dev);
 563
 564         if (d->res.parent)
 565                 release_resource(&d->res);
 566         kfree(d);
 567 }
 568
 569 /**
 570  *      amba_device_register - register an AMBA device
 571  *      @dev: AMBA device to register
 572  *      @parent: parent memory resource
 573  *
 574  *      Setup the AMBA device, reading the cell ID if present.
 575  *      Claim the resource, and register the AMBA device with
 576  *      the Linux device manager.
 577  */
 578 int amba_device_register(struct amba_device *dev, struct resource *parent)
 579 {
 580         u32 size;
 581         void __iomem *tmp;
 582         int i, ret;
 583
 584         device_initialize(&dev->dev);
 585
 586         /*
 587          * Copy from device_add
 588          */
 589         if (dev->dev.init_name) {
 590                 dev_set_name(&dev->dev, "%s", dev->dev.init_name);
 591                 dev->dev.init_name = NULL;
 592         }
 593
 594         dev->dev.release = amba_device_release;
 595         dev->dev.bus = &amba_bustype;
 596         dev->dev.dma_mask = &dev->dma_mask;
 597         dev->res.name = dev_name(&dev->dev);
 598
 599         if (!dev->dev.coherent_dma_mask && dev->dma_mask)
 600                 dev_warn(&dev->dev, "coherent dma mask is unset\n");
 601
 602         ret = request_resource(parent, &dev->res);
 603         if (ret)
 604                 goto err_out;
 605
 606         /* Hard-coded primecell ID instead of plug-n-play */
 607         if (dev->periphid != 0)
 608                 goto skip_probe;
 609
 610         /*
 611          * Dynamically calculate the size of the resource
 612          * and use this for iomap
 613          */
 614         size = resource_size(&dev->res);
 615         tmp = ioremap(dev->res.start, size);
 616         if (!tmp) {
 617                 ret = -ENOMEM;
 618                 goto err_release;
 619         }
 620
 621         ret = amba_get_enable_pclk(dev);
 622         if (ret == 0) {
 623                 u32 pid, cid;
 624
 625                 /*
 626                  * Read pid and cid based on size of resource
 627                  * they are located at end of region
 628                  */
 629                 for (pid = 0, i = 0; i < 4; i++)
 630                         pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) <<
 631                                 (i * 8);
 632                 for (cid = 0, i = 0; i < 4; i++)
 633                         cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
 634                                 (i * 8);
 635
 636                 amba_put_disable_pclk(dev);
 637
 638                 if (cid == AMBA_CID)
 639                         dev->periphid = pid;
 640
 641                 if (!dev->periphid)
 642                         ret = -ENODEV;
 643         }
 644
 645         iounmap(tmp);
 646
 647         if (ret)
 648                 goto err_release;
 649
 650  skip_probe:
 651         ret = device_add(&dev->dev);
 652         if (ret)
 653                 goto err_release;
 654
 655         if (dev->irq[0] != NO_IRQ)
 656                 ret = device_create_file(&dev->dev, &dev_attr_irq0);
 657         if (ret == 0 && dev->irq[1] != NO_IRQ)
 658                 ret = device_create_file(&dev->dev, &dev_attr_irq1);
 659         if (ret == 0)
 660                 return ret;
 661
 662         device_unregister(&dev->dev);
 663
 664  err_release:
 665         release_resource(&dev->res);
 666  err_out:
 667         return ret;
 668 }
 669
 670 /**
 671  *      amba_device_unregister - unregister an AMBA device
 672  *      @dev: AMBA device to remove
 673  *
 674  *      Remove the specified AMBA device from the Linux device
 675  *      manager.  All files associated with this object will be
 676  *      destroyed, and device drivers notified that the device has
 677  *      been removed.  The AMBA device's resources including
 678  *      the amba_device structure will be freed once all
 679  *      references to it have been dropped.
 680  */
 681 void amba_device_unregister(struct amba_device *dev)
 682 {
 683         device_unregister(&dev->dev);
 684 }
 685
 686
 687 struct find_data {
 688         struct amba_device *dev;
 689         struct device *parent;
 690         const char *busid;
 691         unsigned int id;
 692         unsigned int mask;
 693 };
 694
 695 static int amba_find_match(struct device *dev, void *data)
 696 {
 697         struct find_data *d = data;
 698         struct amba_device *pcdev = to_amba_device(dev);
 699         int r;
 700
 701         r = (pcdev->periphid & d->mask) == d->id;
 702         if (d->parent)
 703                 r &= d->parent == dev->parent;
 704         if (d->busid)
 705                 r &= strcmp(dev_name(dev), d->busid) == 0;
 706
 707         if (r) {
 708                 get_device(dev);
 709                 d->dev = pcdev;
 710         }
 711
 712         return r;
 713 }
 714
 715 /**
 716  *      amba_find_device - locate an AMBA device given a bus id
 717  *      @busid: bus id for device (or NULL)
 718  *      @parent: parent device (or NULL)
 719  *      @id: peripheral ID (or 0)
 720  *      @mask: peripheral ID mask (or 0)
 721  *
 722  *      Return the AMBA device corresponding to the supplied parameters.
 723  *      If no device matches, returns NULL.
 724  *
 725  *      NOTE: When a valid device is found, its refcount is
 726  *      incremented, and must be decremented before the returned
 727  *      reference.
 728  */
 729 struct amba_device *
 730 amba_find_device(const char *busid, struct device *parent, unsigned int id,
 731                  unsigned int mask)
 732 {
 733         struct find_data data;
 734
 735         data.dev = NULL;
 736         data.parent = parent;
 737         data.busid = busid;
 738         data.id = id;
 739         data.mask = mask;
 740
 741         bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
 742
 743         return data.dev;
 744 }
 745
 746 /**
 747  *      amba_request_regions - request all mem regions associated with device
 748  *      @dev: amba_device structure for device
 749  *      @name: name, or NULL to use driver name
 750  */
 751 int amba_request_regions(struct amba_device *dev, const char *name)
 752 {
 753         int ret = 0;
 754         u32 size;
 755
 756         if (!name)
 757                 name = dev->dev.driver->name;
 758
 759         size = resource_size(&dev->res);
 760
 761         if (!request_mem_region(dev->res.start, size, name))
 762                 ret = -EBUSY;
 763
 764         return ret;
 765 }
 766
 767 /**
 768  *      amba_release_regions - release mem regions associated with device
 769  *      @dev: amba_device structure for device
 770  *
 771  *      Release regions claimed by a successful call to amba_request_regions.
 772  */
 773 void amba_release_regions(struct amba_device *dev)
 774 {
 775         u32 size;
 776
 777         size = resource_size(&dev->res);
 778         release_mem_region(dev->res.start, size);
 779 }
 780
 781 EXPORT_SYMBOL(amba_driver_register);
 782 EXPORT_SYMBOL(amba_driver_unregister);
 783 EXPORT_SYMBOL(amba_device_register);
 784 EXPORT_SYMBOL(amba_device_unregister);
 785 EXPORT_SYMBOL(amba_find_device);
 786 EXPORT_SYMBOL(amba_request_regions);
 787 EXPORT_SYMBOL(amba_release_regions);