drivers/base/platform.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
platform_get_resource
devm_platform_ioremap_resource
__platform_get_irq
platform_get_irq
platform_get_irq_optional
platform_irq_count
platform_get_resource_byname
__platform_get_irq_byname
platform_get_irq_byname
platform_get_irq_byname_optional
platform_add_devices
setup_pdev_dma_masks
platform_device_put
platform_device_release
platform_device_alloc
platform_device_add_resources
platform_device_add_data
platform_device_add_properties
platform_device_add
platform_device_del
platform_device_register
platform_device_unregister
platform_device_register_full
platform_drv_probe
platform_drv_probe_fail
platform_drv_remove
platform_drv_shutdown
__platform_driver_register
platform_driver_unregister
__platform_driver_probe
__platform_create_bundle
__platform_register_drivers
platform_unregister_drivers
modalias_show
driver_override_store
driver_override_show
platform_uevent
platform_match_id
platform_match
platform_legacy_suspend
platform_legacy_resume
platform_pm_suspend
platform_pm_resume
platform_pm_freeze
platform_pm_thaw
platform_pm_poweroff
platform_pm_restore
platform_dma_configure
__platform_match
platform_find_device_by_driver
platform_bus_init
early_platform_driver_register
early_platform_add_devices
early_platform_driver_register_all
early_platform_match
early_platform_left
early_platform_driver_probe_id
early_platform_driver_probe
early_platform_cleanup
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * platform.c - platform 'pseudo' bus for legacy devices
   4  *
   5  * Copyright (c) 2002-3 Patrick Mochel
   6  * Copyright (c) 2002-3 Open Source Development Labs
   7  *
   8  * Please see Documentation/driver-api/driver-model/platform.rst for more
   9  * information.
  10  */
  11 
  12 #include <linux/string.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/of_device.h>
  15 #include <linux/of_irq.h>
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/dma-mapping.h>
  19 #include <linux/memblock.h>
  20 #include <linux/err.h>
  21 #include <linux/slab.h>
  22 #include <linux/pm_runtime.h>
  23 #include <linux/pm_domain.h>
  24 #include <linux/idr.h>
  25 #include <linux/acpi.h>
  26 #include <linux/clk/clk-conf.h>
  27 #include <linux/limits.h>
  28 #include <linux/property.h>
  29 #include <linux/kmemleak.h>
  30 #include <linux/types.h>
  31 
  32 #include "base.h"
  33 #include "power/power.h"
  34 
  35 /* For automatically allocated device IDs */
  36 static DEFINE_IDA(platform_devid_ida);
  37 
  38 struct device platform_bus = {
  39         .init_name      = "platform",
  40 };
  41 EXPORT_SYMBOL_GPL(platform_bus);
  42 
  43 /**
  44  * platform_get_resource - get a resource for a device
  45  * @dev: platform device
  46  * @type: resource type
  47  * @num: resource index
  48  */
  49 struct resource *platform_get_resource(struct platform_device *dev,
  50                                        unsigned int type, unsigned int num)
  51 {
  52         u32 i;
  53 
  54         for (i = 0; i < dev->num_resources; i++) {
  55                 struct resource *r = &dev->resource[i];
  56 
  57                 if (type == resource_type(r) && num-- == 0)
  58                         return r;
  59         }
  60         return NULL;
  61 }
  62 EXPORT_SYMBOL_GPL(platform_get_resource);
  63 
  64 /**
  65  * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform
  66  *                                  device
  67  *
  68  * @pdev: platform device to use both for memory resource lookup as well as
  69  *        resource management
  70  * @index: resource index
  71  */
  72 #ifdef CONFIG_HAS_IOMEM
  73 void __iomem *devm_platform_ioremap_resource(struct platform_device *pdev,
  74                                              unsigned int index)
  75 {
  76         struct resource *res;
  77 
  78         res = platform_get_resource(pdev, IORESOURCE_MEM, index);
  79         return devm_ioremap_resource(&pdev->dev, res);
  80 }
  81 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource);
  82 #endif /* CONFIG_HAS_IOMEM */
  83 
  84 static int __platform_get_irq(struct platform_device *dev, unsigned int num)
  85 {
  86 #ifdef CONFIG_SPARC
  87         /* sparc does not have irqs represented as IORESOURCE_IRQ resources */
  88         if (!dev || num >= dev->archdata.num_irqs)
  89                 return -ENXIO;
  90         return dev->archdata.irqs[num];
  91 #else
  92         struct resource *r;
  93         if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
  94                 int ret;
  95 
  96                 ret = of_irq_get(dev->dev.of_node, num);
  97                 if (ret > 0 || ret == -EPROBE_DEFER)
  98                         return ret;
  99         }
 100 
 101         r = platform_get_resource(dev, IORESOURCE_IRQ, num);
 102         if (has_acpi_companion(&dev->dev)) {
 103                 if (r && r->flags & IORESOURCE_DISABLED) {
 104                         int ret;
 105 
 106                         ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r);
 107                         if (ret)
 108                                 return ret;
 109                 }
 110         }
 111 
 112         /*
 113          * The resources may pass trigger flags to the irqs that need
 114          * to be set up. It so happens that the trigger flags for
 115          * IORESOURCE_BITS correspond 1-to-1 to the IRQF_TRIGGER*
 116          * settings.
 117          */
 118         if (r && r->flags & IORESOURCE_BITS) {
 119                 struct irq_data *irqd;
 120 
 121                 irqd = irq_get_irq_data(r->start);
 122                 if (!irqd)
 123                         return -ENXIO;
 124                 irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
 125         }
 126 
 127         if (r)
 128                 return r->start;
 129 
 130         /*
 131          * For the index 0 interrupt, allow falling back to GpioInt
 132          * resources. While a device could have both Interrupt and GpioInt
 133          * resources, making this fallback ambiguous, in many common cases
 134          * the device will only expose one IRQ, and this fallback
 135          * allows a common code path across either kind of resource.
 136          */
 137         if (num == 0 && has_acpi_companion(&dev->dev)) {
 138                 int ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num);
 139 
 140                 /* Our callers expect -ENXIO for missing IRQs. */
 141                 if (ret >= 0 || ret == -EPROBE_DEFER)
 142                         return ret;
 143         }
 144 
 145         return -ENXIO;
 146 #endif
 147 }
 148 
 149 /**
 150  * platform_get_irq - get an IRQ for a device
 151  * @dev: platform device
 152  * @num: IRQ number index
 153  *
 154  * Gets an IRQ for a platform device and prints an error message if finding the
 155  * IRQ fails. Device drivers should check the return value for errors so as to
 156  * not pass a negative integer value to the request_irq() APIs.
 157  *
 158  * Example:
 159  *              int irq = platform_get_irq(pdev, 0);
 160  *              if (irq < 0)
 161  *                      return irq;
 162  *
 163  * Return: IRQ number on success, negative error number on failure.
 164  */
 165 int platform_get_irq(struct platform_device *dev, unsigned int num)
 166 {
 167         int ret;
 168 
 169         ret = __platform_get_irq(dev, num);
 170         if (ret < 0 && ret != -EPROBE_DEFER)
 171                 dev_err(&dev->dev, "IRQ index %u not found\n", num);
 172 
 173         return ret;
 174 }
 175 EXPORT_SYMBOL_GPL(platform_get_irq);
 176 
 177 /**
 178  * platform_get_irq_optional - get an optional IRQ for a device
 179  * @dev: platform device
 180  * @num: IRQ number index
 181  *
 182  * Gets an IRQ for a platform device. Device drivers should check the return
 183  * value for errors so as to not pass a negative integer value to the
 184  * request_irq() APIs. This is the same as platform_get_irq(), except that it
 185  * does not print an error message if an IRQ can not be obtained.
 186  *
 187  * Example:
 188  *              int irq = platform_get_irq_optional(pdev, 0);
 189  *              if (irq < 0)
 190  *                      return irq;
 191  *
 192  * Return: IRQ number on success, negative error number on failure.
 193  */
 194 int platform_get_irq_optional(struct platform_device *dev, unsigned int num)
 195 {
 196         return __platform_get_irq(dev, num);
 197 }
 198 EXPORT_SYMBOL_GPL(platform_get_irq_optional);
 199 
 200 /**
 201  * platform_irq_count - Count the number of IRQs a platform device uses
 202  * @dev: platform device
 203  *
 204  * Return: Number of IRQs a platform device uses or EPROBE_DEFER
 205  */
 206 int platform_irq_count(struct platform_device *dev)
 207 {
 208         int ret, nr = 0;
 209 
 210         while ((ret = __platform_get_irq(dev, nr)) >= 0)
 211                 nr++;
 212 
 213         if (ret == -EPROBE_DEFER)
 214                 return ret;
 215 
 216         return nr;
 217 }
 218 EXPORT_SYMBOL_GPL(platform_irq_count);
 219 
 220 /**
 221  * platform_get_resource_byname - get a resource for a device by name
 222  * @dev: platform device
 223  * @type: resource type
 224  * @name: resource name
 225  */
 226 struct resource *platform_get_resource_byname(struct platform_device *dev,
 227                                               unsigned int type,
 228                                               const char *name)
 229 {
 230         u32 i;
 231 
 232         for (i = 0; i < dev->num_resources; i++) {
 233                 struct resource *r = &dev->resource[i];
 234 
 235                 if (unlikely(!r->name))
 236                         continue;
 237 
 238                 if (type == resource_type(r) && !strcmp(r->name, name))
 239                         return r;
 240         }
 241         return NULL;
 242 }
 243 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
 244 
 245 static int __platform_get_irq_byname(struct platform_device *dev,
 246                                      const char *name)
 247 {
 248         struct resource *r;
 249 
 250         if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
 251                 int ret;
 252 
 253                 ret = of_irq_get_byname(dev->dev.of_node, name);
 254                 if (ret > 0 || ret == -EPROBE_DEFER)
 255                         return ret;
 256         }
 257 
 258         r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
 259         if (r)
 260                 return r->start;
 261 
 262         return -ENXIO;
 263 }
 264 
 265 /**
 266  * platform_get_irq_byname - get an IRQ for a device by name
 267  * @dev: platform device
 268  * @name: IRQ name
 269  *
 270  * Get an IRQ like platform_get_irq(), but then by name rather then by index.
 271  *
 272  * Return: IRQ number on success, negative error number on failure.
 273  */
 274 int platform_get_irq_byname(struct platform_device *dev, const char *name)
 275 {
 276         int ret;
 277 
 278         ret = __platform_get_irq_byname(dev, name);
 279         if (ret < 0 && ret != -EPROBE_DEFER)
 280                 dev_err(&dev->dev, "IRQ %s not found\n", name);
 281 
 282         return ret;
 283 }
 284 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
 285 
 286 /**
 287  * platform_get_irq_byname_optional - get an optional IRQ for a device by name
 288  * @dev: platform device
 289  * @name: IRQ name
 290  *
 291  * Get an optional IRQ by name like platform_get_irq_byname(). Except that it
 292  * does not print an error message if an IRQ can not be obtained.
 293  *
 294  * Return: IRQ number on success, negative error number on failure.
 295  */
 296 int platform_get_irq_byname_optional(struct platform_device *dev,
 297                                      const char *name)
 298 {
 299         return __platform_get_irq_byname(dev, name);
 300 }
 301 EXPORT_SYMBOL_GPL(platform_get_irq_byname_optional);
 302 
 303 /**
 304  * platform_add_devices - add a numbers of platform devices
 305  * @devs: array of platform devices to add
 306  * @num: number of platform devices in array
 307  */
 308 int platform_add_devices(struct platform_device **devs, int num)
 309 {
 310         int i, ret = 0;
 311 
 312         for (i = 0; i < num; i++) {
 313                 ret = platform_device_register(devs[i]);
 314                 if (ret) {
 315                         while (--i >= 0)
 316                                 platform_device_unregister(devs[i]);
 317                         break;
 318                 }
 319         }
 320 
 321         return ret;
 322 }
 323 EXPORT_SYMBOL_GPL(platform_add_devices);
 324 
 325 struct platform_object {
 326         struct platform_device pdev;
 327         char name[];
 328 };
 329 
 330 /*
 331  * Set up default DMA mask for platform devices if the they weren't
 332  * previously set by the architecture / DT.
 333  */
 334 static void setup_pdev_dma_masks(struct platform_device *pdev)
 335 {
 336         if (!pdev->dev.coherent_dma_mask)
 337                 pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 338         if (!pdev->dev.dma_mask) {
 339                 pdev->platform_dma_mask = DMA_BIT_MASK(32);
 340                 pdev->dev.dma_mask = &pdev->platform_dma_mask;
 341         }
 342 };
 343 
 344 /**
 345  * platform_device_put - destroy a platform device
 346  * @pdev: platform device to free
 347  *
 348  * Free all memory associated with a platform device.  This function must
 349  * _only_ be externally called in error cases.  All other usage is a bug.
 350  */
 351 void platform_device_put(struct platform_device *pdev)
 352 {
 353         if (!IS_ERR_OR_NULL(pdev))
 354                 put_device(&pdev->dev);
 355 }
 356 EXPORT_SYMBOL_GPL(platform_device_put);
 357 
 358 static void platform_device_release(struct device *dev)
 359 {
 360         struct platform_object *pa = container_of(dev, struct platform_object,
 361                                                   pdev.dev);
 362 
 363         of_device_node_put(&pa->pdev.dev);
 364         kfree(pa->pdev.dev.platform_data);
 365         kfree(pa->pdev.mfd_cell);
 366         kfree(pa->pdev.resource);
 367         kfree(pa->pdev.driver_override);
 368         kfree(pa);
 369 }
 370 
 371 /**
 372  * platform_device_alloc - create a platform device
 373  * @name: base name of the device we're adding
 374  * @id: instance id
 375  *
 376  * Create a platform device object which can have other objects attached
 377  * to it, and which will have attached objects freed when it is released.
 378  */
 379 struct platform_device *platform_device_alloc(const char *name, int id)
 380 {
 381         struct platform_object *pa;
 382 
 383         pa = kzalloc(sizeof(*pa) + strlen(name) + 1, GFP_KERNEL);
 384         if (pa) {
 385                 strcpy(pa->name, name);
 386                 pa->pdev.name = pa->name;
 387                 pa->pdev.id = id;
 388                 device_initialize(&pa->pdev.dev);
 389                 pa->pdev.dev.release = platform_device_release;
 390                 setup_pdev_dma_masks(&pa->pdev);
 391         }
 392 
 393         return pa ? &pa->pdev : NULL;
 394 }
 395 EXPORT_SYMBOL_GPL(platform_device_alloc);
 396 
 397 /**
 398  * platform_device_add_resources - add resources to a platform device
 399  * @pdev: platform device allocated by platform_device_alloc to add resources to
 400  * @res: set of resources that needs to be allocated for the device
 401  * @num: number of resources
 402  *
 403  * Add a copy of the resources to the platform device.  The memory
 404  * associated with the resources will be freed when the platform device is
 405  * released.
 406  */
 407 int platform_device_add_resources(struct platform_device *pdev,
 408                                   const struct resource *res, unsigned int num)
 409 {
 410         struct resource *r = NULL;
 411 
 412         if (res) {
 413                 r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
 414                 if (!r)
 415                         return -ENOMEM;
 416         }
 417 
 418         kfree(pdev->resource);
 419         pdev->resource = r;
 420         pdev->num_resources = num;
 421         return 0;
 422 }
 423 EXPORT_SYMBOL_GPL(platform_device_add_resources);
 424 
 425 /**
 426  * platform_device_add_data - add platform-specific data to a platform device
 427  * @pdev: platform device allocated by platform_device_alloc to add resources to
 428  * @data: platform specific data for this platform device
 429  * @size: size of platform specific data
 430  *
 431  * Add a copy of platform specific data to the platform device's
 432  * platform_data pointer.  The memory associated with the platform data
 433  * will be freed when the platform device is released.
 434  */
 435 int platform_device_add_data(struct platform_device *pdev, const void *data,
 436                              size_t size)
 437 {
 438         void *d = NULL;
 439 
 440         if (data) {
 441                 d = kmemdup(data, size, GFP_KERNEL);
 442                 if (!d)
 443                         return -ENOMEM;
 444         }
 445 
 446         kfree(pdev->dev.platform_data);
 447         pdev->dev.platform_data = d;
 448         return 0;
 449 }
 450 EXPORT_SYMBOL_GPL(platform_device_add_data);
 451 
 452 /**
 453  * platform_device_add_properties - add built-in properties to a platform device
 454  * @pdev: platform device to add properties to
 455  * @properties: null terminated array of properties to add
 456  *
 457  * The function will take deep copy of @properties and attach the copy to the
 458  * platform device. The memory associated with properties will be freed when the
 459  * platform device is released.
 460  */
 461 int platform_device_add_properties(struct platform_device *pdev,
 462                                    const struct property_entry *properties)
 463 {
 464         return device_add_properties(&pdev->dev, properties);
 465 }
 466 EXPORT_SYMBOL_GPL(platform_device_add_properties);
 467 
 468 /**
 469  * platform_device_add - add a platform device to device hierarchy
 470  * @pdev: platform device we're adding
 471  *
 472  * This is part 2 of platform_device_register(), though may be called
 473  * separately _iff_ pdev was allocated by platform_device_alloc().
 474  */
 475 int platform_device_add(struct platform_device *pdev)
 476 {
 477         u32 i;
 478         int ret;
 479 
 480         if (!pdev)
 481                 return -EINVAL;
 482 
 483         if (!pdev->dev.parent)
 484                 pdev->dev.parent = &platform_bus;
 485 
 486         pdev->dev.bus = &platform_bus_type;
 487 
 488         switch (pdev->id) {
 489         default:
 490                 dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
 491                 break;
 492         case PLATFORM_DEVID_NONE:
 493                 dev_set_name(&pdev->dev, "%s", pdev->name);
 494                 break;
 495         case PLATFORM_DEVID_AUTO:
 496                 /*
 497                  * Automatically allocated device ID. We mark it as such so
 498                  * that we remember it must be freed, and we append a suffix
 499                  * to avoid namespace collision with explicit IDs.
 500                  */
 501                 ret = ida_simple_get(&platform_devid_ida, 0, 0, GFP_KERNEL);
 502                 if (ret < 0)
 503                         goto err_out;
 504                 pdev->id = ret;
 505                 pdev->id_auto = true;
 506                 dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
 507                 break;
 508         }
 509 
 510         for (i = 0; i < pdev->num_resources; i++) {
 511                 struct resource *p, *r = &pdev->resource[i];
 512 
 513                 if (r->name == NULL)
 514                         r->name = dev_name(&pdev->dev);
 515 
 516                 p = r->parent;
 517                 if (!p) {
 518                         if (resource_type(r) == IORESOURCE_MEM)
 519                                 p = &iomem_resource;
 520                         else if (resource_type(r) == IORESOURCE_IO)
 521                                 p = &ioport_resource;
 522                 }
 523 
 524                 if (p) {
 525                         ret = insert_resource(p, r);
 526                         if (ret) {
 527                                 dev_err(&pdev->dev, "failed to claim resource %d: %pR\n", i, r);
 528                                 goto failed;
 529                         }
 530                 }
 531         }
 532 
 533         pr_debug("Registering platform device '%s'. Parent at %s\n",
 534                  dev_name(&pdev->dev), dev_name(pdev->dev.parent));
 535 
 536         ret = device_add(&pdev->dev);
 537         if (ret == 0)
 538                 return ret;
 539 
 540  failed:
 541         if (pdev->id_auto) {
 542                 ida_simple_remove(&platform_devid_ida, pdev->id);
 543                 pdev->id = PLATFORM_DEVID_AUTO;
 544         }
 545 
 546         while (i--) {
 547                 struct resource *r = &pdev->resource[i];
 548                 if (r->parent)
 549                         release_resource(r);
 550         }
 551 
 552  err_out:
 553         return ret;
 554 }
 555 EXPORT_SYMBOL_GPL(platform_device_add);
 556 
 557 /**
 558  * platform_device_del - remove a platform-level device
 559  * @pdev: platform device we're removing
 560  *
 561  * Note that this function will also release all memory- and port-based
 562  * resources owned by the device (@dev->resource).  This function must
 563  * _only_ be externally called in error cases.  All other usage is a bug.
 564  */
 565 void platform_device_del(struct platform_device *pdev)
 566 {
 567         u32 i;
 568 
 569         if (!IS_ERR_OR_NULL(pdev)) {
 570                 device_del(&pdev->dev);
 571 
 572                 if (pdev->id_auto) {
 573                         ida_simple_remove(&platform_devid_ida, pdev->id);
 574                         pdev->id = PLATFORM_DEVID_AUTO;
 575                 }
 576 
 577                 for (i = 0; i < pdev->num_resources; i++) {
 578                         struct resource *r = &pdev->resource[i];
 579                         if (r->parent)
 580                                 release_resource(r);
 581                 }
 582         }
 583 }
 584 EXPORT_SYMBOL_GPL(platform_device_del);
 585 
 586 /**
 587  * platform_device_register - add a platform-level device
 588  * @pdev: platform device we're adding
 589  */
 590 int platform_device_register(struct platform_device *pdev)
 591 {
 592         device_initialize(&pdev->dev);
 593         setup_pdev_dma_masks(pdev);
 594         return platform_device_add(pdev);
 595 }
 596 EXPORT_SYMBOL_GPL(platform_device_register);
 597 
 598 /**
 599  * platform_device_unregister - unregister a platform-level device
 600  * @pdev: platform device we're unregistering
 601  *
 602  * Unregistration is done in 2 steps. First we release all resources
 603  * and remove it from the subsystem, then we drop reference count by
 604  * calling platform_device_put().
 605  */
 606 void platform_device_unregister(struct platform_device *pdev)
 607 {
 608         platform_device_del(pdev);
 609         platform_device_put(pdev);
 610 }
 611 EXPORT_SYMBOL_GPL(platform_device_unregister);
 612 
 613 /**
 614  * platform_device_register_full - add a platform-level device with
 615  * resources and platform-specific data
 616  *
 617  * @pdevinfo: data used to create device
 618  *
 619  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
 620  */
 621 struct platform_device *platform_device_register_full(
 622                 const struct platform_device_info *pdevinfo)
 623 {
 624         int ret = -ENOMEM;
 625         struct platform_device *pdev;
 626 
 627         pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
 628         if (!pdev)
 629                 return ERR_PTR(-ENOMEM);
 630 
 631         pdev->dev.parent = pdevinfo->parent;
 632         pdev->dev.fwnode = pdevinfo->fwnode;
 633         pdev->dev.of_node = of_node_get(to_of_node(pdev->dev.fwnode));
 634         pdev->dev.of_node_reused = pdevinfo->of_node_reused;
 635 
 636         if (pdevinfo->dma_mask) {
 637                 pdev->platform_dma_mask = pdevinfo->dma_mask;
 638                 pdev->dev.dma_mask = &pdev->platform_dma_mask;
 639                 pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
 640         }
 641 
 642         ret = platform_device_add_resources(pdev,
 643                         pdevinfo->res, pdevinfo->num_res);
 644         if (ret)
 645                 goto err;
 646 
 647         ret = platform_device_add_data(pdev,
 648                         pdevinfo->data, pdevinfo->size_data);
 649         if (ret)
 650                 goto err;
 651 
 652         if (pdevinfo->properties) {
 653                 ret = platform_device_add_properties(pdev,
 654                                                      pdevinfo->properties);
 655                 if (ret)
 656                         goto err;
 657         }
 658 
 659         ret = platform_device_add(pdev);
 660         if (ret) {
 661 err:
 662                 ACPI_COMPANION_SET(&pdev->dev, NULL);
 663                 platform_device_put(pdev);
 664                 return ERR_PTR(ret);
 665         }
 666 
 667         return pdev;
 668 }
 669 EXPORT_SYMBOL_GPL(platform_device_register_full);
 670 
 671 static int platform_drv_probe(struct device *_dev)
 672 {
 673         struct platform_driver *drv = to_platform_driver(_dev->driver);
 674         struct platform_device *dev = to_platform_device(_dev);
 675         int ret;
 676 
 677         ret = of_clk_set_defaults(_dev->of_node, false);
 678         if (ret < 0)
 679                 return ret;
 680 
 681         ret = dev_pm_domain_attach(_dev, true);
 682         if (ret)
 683                 goto out;
 684 
 685         if (drv->probe) {
 686                 ret = drv->probe(dev);
 687                 if (ret)
 688                         dev_pm_domain_detach(_dev, true);
 689         }
 690 
 691 out:
 692         if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
 693                 dev_warn(_dev, "probe deferral not supported\n");
 694                 ret = -ENXIO;
 695         }
 696 
 697         return ret;
 698 }
 699 
 700 static int platform_drv_probe_fail(struct device *_dev)
 701 {
 702         return -ENXIO;
 703 }
 704 
 705 static int platform_drv_remove(struct device *_dev)
 706 {
 707         struct platform_driver *drv = to_platform_driver(_dev->driver);
 708         struct platform_device *dev = to_platform_device(_dev);
 709         int ret = 0;
 710 
 711         if (drv->remove)
 712                 ret = drv->remove(dev);
 713         dev_pm_domain_detach(_dev, true);
 714 
 715         return ret;
 716 }
 717 
 718 static void platform_drv_shutdown(struct device *_dev)
 719 {
 720         struct platform_driver *drv = to_platform_driver(_dev->driver);
 721         struct platform_device *dev = to_platform_device(_dev);
 722 
 723         if (drv->shutdown)
 724                 drv->shutdown(dev);
 725 }
 726 
 727 /**
 728  * __platform_driver_register - register a driver for platform-level devices
 729  * @drv: platform driver structure
 730  * @owner: owning module/driver
 731  */
 732 int __platform_driver_register(struct platform_driver *drv,
 733                                 struct module *owner)
 734 {
 735         drv->driver.owner = owner;
 736         drv->driver.bus = &platform_bus_type;
 737         drv->driver.probe = platform_drv_probe;
 738         drv->driver.remove = platform_drv_remove;
 739         drv->driver.shutdown = platform_drv_shutdown;
 740 
 741         return driver_register(&drv->driver);
 742 }
 743 EXPORT_SYMBOL_GPL(__platform_driver_register);
 744 
 745 /**
 746  * platform_driver_unregister - unregister a driver for platform-level devices
 747  * @drv: platform driver structure
 748  */
 749 void platform_driver_unregister(struct platform_driver *drv)
 750 {
 751         driver_unregister(&drv->driver);
 752 }
 753 EXPORT_SYMBOL_GPL(platform_driver_unregister);
 754 
 755 /**
 756  * __platform_driver_probe - register driver for non-hotpluggable device
 757  * @drv: platform driver structure
 758  * @probe: the driver probe routine, probably from an __init section
 759  * @module: module which will be the owner of the driver
 760  *
 761  * Use this instead of platform_driver_register() when you know the device
 762  * is not hotpluggable and has already been registered, and you want to
 763  * remove its run-once probe() infrastructure from memory after the driver
 764  * has bound to the device.
 765  *
 766  * One typical use for this would be with drivers for controllers integrated
 767  * into system-on-chip processors, where the controller devices have been
 768  * configured as part of board setup.
 769  *
 770  * Note that this is incompatible with deferred probing.
 771  *
 772  * Returns zero if the driver registered and bound to a device, else returns
 773  * a negative error code and with the driver not registered.
 774  */
 775 int __init_or_module __platform_driver_probe(struct platform_driver *drv,
 776                 int (*probe)(struct platform_device *), struct module *module)
 777 {
 778         int retval, code;
 779 
 780         if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
 781                 pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
 782                          drv->driver.name, __func__);
 783                 return -EINVAL;
 784         }
 785 
 786         /*
 787          * We have to run our probes synchronously because we check if
 788          * we find any devices to bind to and exit with error if there
 789          * are any.
 790          */
 791         drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
 792 
 793         /*
 794          * Prevent driver from requesting probe deferral to avoid further
 795          * futile probe attempts.
 796          */
 797         drv->prevent_deferred_probe = true;
 798 
 799         /* make sure driver won't have bind/unbind attributes */
 800         drv->driver.suppress_bind_attrs = true;
 801 
 802         /* temporary section violation during probe() */
 803         drv->probe = probe;
 804         retval = code = __platform_driver_register(drv, module);
 805 
 806         /*
 807          * Fixup that section violation, being paranoid about code scanning
 808          * the list of drivers in order to probe new devices.  Check to see
 809          * if the probe was successful, and make sure any forced probes of
 810          * new devices fail.
 811          */
 812         spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
 813         drv->probe = NULL;
 814         if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
 815                 retval = -ENODEV;
 816         drv->driver.probe = platform_drv_probe_fail;
 817         spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
 818 
 819         if (code != retval)
 820                 platform_driver_unregister(drv);
 821         return retval;
 822 }
 823 EXPORT_SYMBOL_GPL(__platform_driver_probe);
 824 
 825 /**
 826  * __platform_create_bundle - register driver and create corresponding device
 827  * @driver: platform driver structure
 828  * @probe: the driver probe routine, probably from an __init section
 829  * @res: set of resources that needs to be allocated for the device
 830  * @n_res: number of resources
 831  * @data: platform specific data for this platform device
 832  * @size: size of platform specific data
 833  * @module: module which will be the owner of the driver
 834  *
 835  * Use this in legacy-style modules that probe hardware directly and
 836  * register a single platform device and corresponding platform driver.
 837  *
 838  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
 839  */
 840 struct platform_device * __init_or_module __platform_create_bundle(
 841                         struct platform_driver *driver,
 842                         int (*probe)(struct platform_device *),
 843                         struct resource *res, unsigned int n_res,
 844                         const void *data, size_t size, struct module *module)
 845 {
 846         struct platform_device *pdev;
 847         int error;
 848 
 849         pdev = platform_device_alloc(driver->driver.name, -1);
 850         if (!pdev) {
 851                 error = -ENOMEM;
 852                 goto err_out;
 853         }
 854 
 855         error = platform_device_add_resources(pdev, res, n_res);
 856         if (error)
 857                 goto err_pdev_put;
 858 
 859         error = platform_device_add_data(pdev, data, size);
 860         if (error)
 861                 goto err_pdev_put;
 862 
 863         error = platform_device_add(pdev);
 864         if (error)
 865                 goto err_pdev_put;
 866 
 867         error = __platform_driver_probe(driver, probe, module);
 868         if (error)
 869                 goto err_pdev_del;
 870 
 871         return pdev;
 872 
 873 err_pdev_del:
 874         platform_device_del(pdev);
 875 err_pdev_put:
 876         platform_device_put(pdev);
 877 err_out:
 878         return ERR_PTR(error);
 879 }
 880 EXPORT_SYMBOL_GPL(__platform_create_bundle);
 881 
 882 /**
 883  * __platform_register_drivers - register an array of platform drivers
 884  * @drivers: an array of drivers to register
 885  * @count: the number of drivers to register
 886  * @owner: module owning the drivers
 887  *
 888  * Registers platform drivers specified by an array. On failure to register a
 889  * driver, all previously registered drivers will be unregistered. Callers of
 890  * this API should use platform_unregister_drivers() to unregister drivers in
 891  * the reverse order.
 892  *
 893  * Returns: 0 on success or a negative error code on failure.
 894  */
 895 int __platform_register_drivers(struct platform_driver * const *drivers,
 896                                 unsigned int count, struct module *owner)
 897 {
 898         unsigned int i;
 899         int err;
 900 
 901         for (i = 0; i < count; i++) {
 902                 pr_debug("registering platform driver %ps\n", drivers[i]);
 903 
 904                 err = __platform_driver_register(drivers[i], owner);
 905                 if (err < 0) {
 906                         pr_err("failed to register platform driver %ps: %d\n",
 907                                drivers[i], err);
 908                         goto error;
 909                 }
 910         }
 911 
 912         return 0;
 913 
 914 error:
 915         while (i--) {
 916                 pr_debug("unregistering platform driver %ps\n", drivers[i]);
 917                 platform_driver_unregister(drivers[i]);
 918         }
 919 
 920         return err;
 921 }
 922 EXPORT_SYMBOL_GPL(__platform_register_drivers);
 923 
 924 /**
 925  * platform_unregister_drivers - unregister an array of platform drivers
 926  * @drivers: an array of drivers to unregister
 927  * @count: the number of drivers to unregister
 928  *
 929  * Unegisters platform drivers specified by an array. This is typically used
 930  * to complement an earlier call to platform_register_drivers(). Drivers are
 931  * unregistered in the reverse order in which they were registered.
 932  */
 933 void platform_unregister_drivers(struct platform_driver * const *drivers,
 934                                  unsigned int count)
 935 {
 936         while (count--) {
 937                 pr_debug("unregistering platform driver %ps\n", drivers[count]);
 938                 platform_driver_unregister(drivers[count]);
 939         }
 940 }
 941 EXPORT_SYMBOL_GPL(platform_unregister_drivers);
 942 
 943 /* modalias support enables more hands-off userspace setup:
 944  * (a) environment variable lets new-style hotplug events work once system is
 945  *     fully running:  "modprobe $MODALIAS"
 946  * (b) sysfs attribute lets new-style coldplug recover from hotplug events
 947  *     mishandled before system is fully running:  "modprobe $(cat modalias)"
 948  */
 949 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
 950                              char *buf)
 951 {
 952         struct platform_device  *pdev = to_platform_device(dev);
 953         int len;
 954 
 955         len = of_device_modalias(dev, buf, PAGE_SIZE);
 956         if (len != -ENODEV)
 957                 return len;
 958 
 959         len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
 960         if (len != -ENODEV)
 961                 return len;
 962 
 963         len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
 964 
 965         return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
 966 }
 967 static DEVICE_ATTR_RO(modalias);
 968 
 969 static ssize_t driver_override_store(struct device *dev,
 970                                      struct device_attribute *attr,
 971                                      const char *buf, size_t count)
 972 {
 973         struct platform_device *pdev = to_platform_device(dev);
 974         char *driver_override, *old, *cp;
 975 
 976         /* We need to keep extra room for a newline */
 977         if (count >= (PAGE_SIZE - 1))
 978                 return -EINVAL;
 979 
 980         driver_override = kstrndup(buf, count, GFP_KERNEL);
 981         if (!driver_override)
 982                 return -ENOMEM;
 983 
 984         cp = strchr(driver_override, '\n');
 985         if (cp)
 986                 *cp = '\0';
 987 
 988         device_lock(dev);
 989         old = pdev->driver_override;
 990         if (strlen(driver_override)) {
 991                 pdev->driver_override = driver_override;
 992         } else {
 993                 kfree(driver_override);
 994                 pdev->driver_override = NULL;
 995         }
 996         device_unlock(dev);
 997 
 998         kfree(old);
 999 
1000         return count;
1001 }
1002 
1003 static ssize_t driver_override_show(struct device *dev,
1004                                     struct device_attribute *attr, char *buf)
1005 {
1006         struct platform_device *pdev = to_platform_device(dev);
1007         ssize_t len;
1008 
1009         device_lock(dev);
1010         len = sprintf(buf, "%s\n", pdev->driver_override);
1011         device_unlock(dev);
1012         return len;
1013 }
1014 static DEVICE_ATTR_RW(driver_override);
1015 
1016 
1017 static struct attribute *platform_dev_attrs[] = {
1018         &dev_attr_modalias.attr,
1019         &dev_attr_driver_override.attr,
1020         NULL,
1021 };
1022 ATTRIBUTE_GROUPS(platform_dev);
1023 
1024 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
1025 {
1026         struct platform_device  *pdev = to_platform_device(dev);
1027         int rc;
1028 
1029         /* Some devices have extra OF data and an OF-style MODALIAS */
1030         rc = of_device_uevent_modalias(dev, env);
1031         if (rc != -ENODEV)
1032                 return rc;
1033 
1034         rc = acpi_device_uevent_modalias(dev, env);
1035         if (rc != -ENODEV)
1036                 return rc;
1037 
1038         add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
1039                         pdev->name);
1040         return 0;
1041 }
1042 
1043 static const struct platform_device_id *platform_match_id(
1044                         const struct platform_device_id *id,
1045                         struct platform_device *pdev)
1046 {
1047         while (id->name[0]) {
1048                 if (strcmp(pdev->name, id->name) == 0) {
1049                         pdev->id_entry = id;
1050                         return id;
1051                 }
1052                 id++;
1053         }
1054         return NULL;
1055 }
1056 
1057 /**
1058  * platform_match - bind platform device to platform driver.
1059  * @dev: device.
1060  * @drv: driver.
1061  *
1062  * Platform device IDs are assumed to be encoded like this:
1063  * "<name><instance>", where <name> is a short description of the type of
1064  * device, like "pci" or "floppy", and <instance> is the enumerated
1065  * instance of the device, like '0' or '42'.  Driver IDs are simply
1066  * "<name>".  So, extract the <name> from the platform_device structure,
1067  * and compare it against the name of the driver. Return whether they match
1068  * or not.
1069  */
1070 static int platform_match(struct device *dev, struct device_driver *drv)
1071 {
1072         struct platform_device *pdev = to_platform_device(dev);
1073         struct platform_driver *pdrv = to_platform_driver(drv);
1074 
1075         /* When driver_override is set, only bind to the matching driver */
1076         if (pdev->driver_override)
1077                 return !strcmp(pdev->driver_override, drv->name);
1078 
1079         /* Attempt an OF style match first */
1080         if (of_driver_match_device(dev, drv))
1081                 return 1;
1082 
1083         /* Then try ACPI style match */
1084         if (acpi_driver_match_device(dev, drv))
1085                 return 1;
1086 
1087         /* Then try to match against the id table */
1088         if (pdrv->id_table)
1089                 return platform_match_id(pdrv->id_table, pdev) != NULL;
1090 
1091         /* fall-back to driver name match */
1092         return (strcmp(pdev->name, drv->name) == 0);
1093 }
1094 
1095 #ifdef CONFIG_PM_SLEEP
1096 
1097 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
1098 {
1099         struct platform_driver *pdrv = to_platform_driver(dev->driver);
1100         struct platform_device *pdev = to_platform_device(dev);
1101         int ret = 0;
1102 
1103         if (dev->driver && pdrv->suspend)
1104                 ret = pdrv->suspend(pdev, mesg);
1105 
1106         return ret;
1107 }
1108 
1109 static int platform_legacy_resume(struct device *dev)
1110 {
1111         struct platform_driver *pdrv = to_platform_driver(dev->driver);
1112         struct platform_device *pdev = to_platform_device(dev);
1113         int ret = 0;
1114 
1115         if (dev->driver && pdrv->resume)
1116                 ret = pdrv->resume(pdev);
1117 
1118         return ret;
1119 }
1120 
1121 #endif /* CONFIG_PM_SLEEP */
1122 
1123 #ifdef CONFIG_SUSPEND
1124 
1125 int platform_pm_suspend(struct device *dev)
1126 {
1127         struct device_driver *drv = dev->driver;
1128         int ret = 0;
1129 
1130         if (!drv)
1131                 return 0;
1132 
1133         if (drv->pm) {
1134                 if (drv->pm->suspend)
1135                         ret = drv->pm->suspend(dev);
1136         } else {
1137                 ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
1138         }
1139 
1140         return ret;
1141 }
1142 
1143 int platform_pm_resume(struct device *dev)
1144 {
1145         struct device_driver *drv = dev->driver;
1146         int ret = 0;
1147 
1148         if (!drv)
1149                 return 0;
1150 
1151         if (drv->pm) {
1152                 if (drv->pm->resume)
1153                         ret = drv->pm->resume(dev);
1154         } else {
1155                 ret = platform_legacy_resume(dev);
1156         }
1157 
1158         return ret;
1159 }
1160 
1161 #endif /* CONFIG_SUSPEND */
1162 
1163 #ifdef CONFIG_HIBERNATE_CALLBACKS
1164 
1165 int platform_pm_freeze(struct device *dev)
1166 {
1167         struct device_driver *drv = dev->driver;
1168         int ret = 0;
1169 
1170         if (!drv)
1171                 return 0;
1172 
1173         if (drv->pm) {
1174                 if (drv->pm->freeze)
1175                         ret = drv->pm->freeze(dev);
1176         } else {
1177                 ret = platform_legacy_suspend(dev, PMSG_FREEZE);
1178         }
1179 
1180         return ret;
1181 }
1182 
1183 int platform_pm_thaw(struct device *dev)
1184 {
1185         struct device_driver *drv = dev->driver;
1186         int ret = 0;
1187 
1188         if (!drv)
1189                 return 0;
1190 
1191         if (drv->pm) {
1192                 if (drv->pm->thaw)
1193                         ret = drv->pm->thaw(dev);
1194         } else {
1195                 ret = platform_legacy_resume(dev);
1196         }
1197 
1198         return ret;
1199 }
1200 
1201 int platform_pm_poweroff(struct device *dev)
1202 {
1203         struct device_driver *drv = dev->driver;
1204         int ret = 0;
1205 
1206         if (!drv)
1207                 return 0;
1208 
1209         if (drv->pm) {
1210                 if (drv->pm->poweroff)
1211                         ret = drv->pm->poweroff(dev);
1212         } else {
1213                 ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
1214         }
1215 
1216         return ret;
1217 }
1218 
1219 int platform_pm_restore(struct device *dev)
1220 {
1221         struct device_driver *drv = dev->driver;
1222         int ret = 0;
1223 
1224         if (!drv)
1225                 return 0;
1226 
1227         if (drv->pm) {
1228                 if (drv->pm->restore)
1229                         ret = drv->pm->restore(dev);
1230         } else {
1231                 ret = platform_legacy_resume(dev);
1232         }
1233 
1234         return ret;
1235 }
1236 
1237 #endif /* CONFIG_HIBERNATE_CALLBACKS */
1238 
1239 int platform_dma_configure(struct device *dev)
1240 {
1241         enum dev_dma_attr attr;
1242         int ret = 0;
1243 
1244         if (dev->of_node) {
1245                 ret = of_dma_configure(dev, dev->of_node, true);
1246         } else if (has_acpi_companion(dev)) {
1247                 attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
1248                 ret = acpi_dma_configure(dev, attr);
1249         }
1250 
1251         return ret;
1252 }
1253 
1254 static const struct dev_pm_ops platform_dev_pm_ops = {
1255         .runtime_suspend = pm_generic_runtime_suspend,
1256         .runtime_resume = pm_generic_runtime_resume,
1257         USE_PLATFORM_PM_SLEEP_OPS
1258 };
1259 
1260 struct bus_type platform_bus_type = {
1261         .name           = "platform",
1262         .dev_groups     = platform_dev_groups,
1263         .match          = platform_match,
1264         .uevent         = platform_uevent,
1265         .dma_configure  = platform_dma_configure,
1266         .pm             = &platform_dev_pm_ops,
1267 };
1268 EXPORT_SYMBOL_GPL(platform_bus_type);
1269 
1270 static inline int __platform_match(struct device *dev, const void *drv)
1271 {
1272         return platform_match(dev, (struct device_driver *)drv);
1273 }
1274 
1275 /**
1276  * platform_find_device_by_driver - Find a platform device with a given
1277  * driver.
1278  * @start: The device to start the search from.
1279  * @drv: The device driver to look for.
1280  */
1281 struct device *platform_find_device_by_driver(struct device *start,
1282                                               const struct device_driver *drv)
1283 {
1284         return bus_find_device(&platform_bus_type, start, drv,
1285                                __platform_match);
1286 }
1287 EXPORT_SYMBOL_GPL(platform_find_device_by_driver);
1288 
1289 int __init platform_bus_init(void)
1290 {
1291         int error;
1292 
1293         early_platform_cleanup();
1294 
1295         error = device_register(&platform_bus);
1296         if (error) {
1297                 put_device(&platform_bus);
1298                 return error;
1299         }
1300         error =  bus_register(&platform_bus_type);
1301         if (error)
1302                 device_unregister(&platform_bus);
1303         of_platform_register_reconfig_notifier();
1304         return error;
1305 }
1306 
1307 static __initdata LIST_HEAD(early_platform_driver_list);
1308 static __initdata LIST_HEAD(early_platform_device_list);
1309 
1310 /**
1311  * early_platform_driver_register - register early platform driver
1312  * @epdrv: early_platform driver structure
1313  * @buf: string passed from early_param()
1314  *
1315  * Helper function for early_platform_init() / early_platform_init_buffer()
1316  */
1317 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
1318                                           char *buf)
1319 {
1320         char *tmp;
1321         int n;
1322 
1323         /* Simply add the driver to the end of the global list.
1324          * Drivers will by default be put on the list in compiled-in order.
1325          */
1326         if (!epdrv->list.next) {
1327                 INIT_LIST_HEAD(&epdrv->list);
1328                 list_add_tail(&epdrv->list, &early_platform_driver_list);
1329         }
1330 
1331         /* If the user has specified device then make sure the driver
1332          * gets prioritized. The driver of the last device specified on
1333          * command line will be put first on the list.
1334          */
1335         n = strlen(epdrv->pdrv->driver.name);
1336         if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1337                 list_move(&epdrv->list, &early_platform_driver_list);
1338 
1339                 /* Allow passing parameters after device name */
1340                 if (buf[n] == '\0' || buf[n] == ',')
1341                         epdrv->requested_id = -1;
1342                 else {
1343                         epdrv->requested_id = simple_strtoul(&buf[n + 1],
1344                                                              &tmp, 10);
1345 
1346                         if (buf[n] != '.' || (tmp == &buf[n + 1])) {
1347                                 epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1348                                 n = 0;
1349                         } else
1350                                 n += strcspn(&buf[n + 1], ",") + 1;
1351                 }
1352 
1353                 if (buf[n] == ',')
1354                         n++;
1355 
1356                 if (epdrv->bufsize) {
1357                         memcpy(epdrv->buffer, &buf[n],
1358                                min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
1359                         epdrv->buffer[epdrv->bufsize - 1] = '\0';
1360                 }
1361         }
1362 
1363         return 0;
1364 }
1365 
1366 /**
1367  * early_platform_add_devices - adds a number of early platform devices
1368  * @devs: array of early platform devices to add
1369  * @num: number of early platform devices in array
1370  *
1371  * Used by early architecture code to register early platform devices and
1372  * their platform data.
1373  */
1374 void __init early_platform_add_devices(struct platform_device **devs, int num)
1375 {
1376         struct device *dev;
1377         int i;
1378 
1379         /* simply add the devices to list */
1380         for (i = 0; i < num; i++) {
1381                 dev = &devs[i]->dev;
1382 
1383                 if (!dev->devres_head.next) {
1384                         pm_runtime_early_init(dev);
1385                         INIT_LIST_HEAD(&dev->devres_head);
1386                         list_add_tail(&dev->devres_head,
1387                                       &early_platform_device_list);
1388                 }
1389         }
1390 }
1391 
1392 /**
1393  * early_platform_driver_register_all - register early platform drivers
1394  * @class_str: string to identify early platform driver class
1395  *
1396  * Used by architecture code to register all early platform drivers
1397  * for a certain class. If omitted then only early platform drivers
1398  * with matching kernel command line class parameters will be registered.
1399  */
1400 void __init early_platform_driver_register_all(char *class_str)
1401 {
1402         /* The "class_str" parameter may or may not be present on the kernel
1403          * command line. If it is present then there may be more than one
1404          * matching parameter.
1405          *
1406          * Since we register our early platform drivers using early_param()
1407          * we need to make sure that they also get registered in the case
1408          * when the parameter is missing from the kernel command line.
1409          *
1410          * We use parse_early_options() to make sure the early_param() gets
1411          * called at least once. The early_param() may be called more than
1412          * once since the name of the preferred device may be specified on
1413          * the kernel command line. early_platform_driver_register() handles
1414          * this case for us.
1415          */
1416         parse_early_options(class_str);
1417 }
1418 
1419 /**
1420  * early_platform_match - find early platform device matching driver
1421  * @epdrv: early platform driver structure
1422  * @id: id to match against
1423  */
1424 static struct platform_device * __init
1425 early_platform_match(struct early_platform_driver *epdrv, int id)
1426 {
1427         struct platform_device *pd;
1428 
1429         list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1430                 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1431                         if (pd->id == id)
1432                                 return pd;
1433 
1434         return NULL;
1435 }
1436 
1437 /**
1438  * early_platform_left - check if early platform driver has matching devices
1439  * @epdrv: early platform driver structure
1440  * @id: return true if id or above exists
1441  */
1442 static int __init early_platform_left(struct early_platform_driver *epdrv,
1443                                        int id)
1444 {
1445         struct platform_device *pd;
1446 
1447         list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1448                 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1449                         if (pd->id >= id)
1450                                 return 1;
1451 
1452         return 0;
1453 }
1454 
1455 /**
1456  * early_platform_driver_probe_id - probe drivers matching class_str and id
1457  * @class_str: string to identify early platform driver class
1458  * @id: id to match against
1459  * @nr_probe: number of platform devices to successfully probe before exiting
1460  */
1461 static int __init early_platform_driver_probe_id(char *class_str,
1462                                                  int id,
1463                                                  int nr_probe)
1464 {
1465         struct early_platform_driver *epdrv;
1466         struct platform_device *match;
1467         int match_id;
1468         int n = 0;
1469         int left = 0;
1470 
1471         list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1472                 /* only use drivers matching our class_str */
1473                 if (strcmp(class_str, epdrv->class_str))
1474                         continue;
1475 
1476                 if (id == -2) {
1477                         match_id = epdrv->requested_id;
1478                         left = 1;
1479 
1480                 } else {
1481                         match_id = id;
1482                         left += early_platform_left(epdrv, id);
1483 
1484                         /* skip requested id */
1485                         switch (epdrv->requested_id) {
1486                         case EARLY_PLATFORM_ID_ERROR:
1487                         case EARLY_PLATFORM_ID_UNSET:
1488                                 break;
1489                         default:
1490                                 if (epdrv->requested_id == id)
1491                                         match_id = EARLY_PLATFORM_ID_UNSET;
1492                         }
1493                 }
1494 
1495                 switch (match_id) {
1496                 case EARLY_PLATFORM_ID_ERROR:
1497                         pr_warn("%s: unable to parse %s parameter\n",
1498                                 class_str, epdrv->pdrv->driver.name);
1499                         /* fall-through */
1500                 case EARLY_PLATFORM_ID_UNSET:
1501                         match = NULL;
1502                         break;
1503                 default:
1504                         match = early_platform_match(epdrv, match_id);
1505                 }
1506 
1507                 if (match) {
1508                         /*
1509                          * Set up a sensible init_name to enable
1510                          * dev_name() and others to be used before the
1511                          * rest of the driver core is initialized.
1512                          */
1513                         if (!match->dev.init_name && slab_is_available()) {
1514                                 if (match->id != -1)
1515                                         match->dev.init_name =
1516                                                 kasprintf(GFP_KERNEL, "%s.%d",
1517                                                           match->name,
1518                                                           match->id);
1519                                 else
1520                                         match->dev.init_name =
1521                                                 kasprintf(GFP_KERNEL, "%s",
1522                                                           match->name);
1523 
1524                                 if (!match->dev.init_name)
1525                                         return -ENOMEM;
1526                         }
1527 
1528                         if (epdrv->pdrv->probe(match))
1529                                 pr_warn("%s: unable to probe %s early.\n",
1530                                         class_str, match->name);
1531                         else
1532                                 n++;
1533                 }
1534 
1535                 if (n >= nr_probe)
1536                         break;
1537         }
1538 
1539         if (left)
1540                 return n;
1541         else
1542                 return -ENODEV;
1543 }
1544 
1545 /**
1546  * early_platform_driver_probe - probe a class of registered drivers
1547  * @class_str: string to identify early platform driver class
1548  * @nr_probe: number of platform devices to successfully probe before exiting
1549  * @user_only: only probe user specified early platform devices
1550  *
1551  * Used by architecture code to probe registered early platform drivers
1552  * within a certain class. For probe to happen a registered early platform
1553  * device matching a registered early platform driver is needed.
1554  */
1555 int __init early_platform_driver_probe(char *class_str,
1556                                        int nr_probe,
1557                                        int user_only)
1558 {
1559         int k, n, i;
1560 
1561         n = 0;
1562         for (i = -2; n < nr_probe; i++) {
1563                 k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1564 
1565                 if (k < 0)
1566                         break;
1567 
1568                 n += k;
1569 
1570                 if (user_only)
1571                         break;
1572         }
1573 
1574         return n;
1575 }
1576 
1577 /**
1578  * early_platform_cleanup - clean up early platform code
1579  */
1580 void __init early_platform_cleanup(void)
1581 {
1582         struct platform_device *pd, *pd2;
1583 
1584         /* clean up the devres list used to chain devices */
1585         list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1586                                  dev.devres_head) {
1587                 list_del(&pd->dev.devres_head);
1588                 memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
1589         }
1590 }
1591
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root/drivers/base/platform.c

DEFINITIONS
