/*
   * platform.c - platform 'pseudo' bus for legacy devices
   *
   * Copyright (c) 2002-3 Patrick Mochel
   * Copyright (c) 2002-3 Open Source Development Labs
   *
   * This file is released under the GPLv2
   *
   * Please see Documentation/driver-model/platform.txt for more
   * information.
   */

  #include <linux/string.h>

  #include <linux/platform_device.h>

  #include <linux/of_device.h>

  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/dma-mapping.h>
  #include <linux/bootmem.h>
  #include <linux/err.h>

  #include <linux/slab.h>

  #include <linux/pm_runtime.h>

  #include "base.h"

  #define to_platform_driver(drv)	(container_of((drv), struct platform_driver, \
  				 driver))

  struct device platform_bus = {

  	.init_name	= "platform",

  };

  EXPORT_SYMBOL_GPL(platform_bus);

  
  /**

   * platform_get_resource - get a resource for a device
   * @dev: platform device
   * @type: resource type
   * @num: resource index

   */

  struct resource *platform_get_resource(struct platform_device *dev,
  				       unsigned int type, unsigned int num)

  {
  	int i;
  
  	for (i = 0; i < dev->num_resources; i++) {
  		struct resource *r = &dev->resource[i];

  		if (type == resource_type(r) && num-- == 0)
  			return r;

  	}
  	return NULL;
  }

  EXPORT_SYMBOL_GPL(platform_get_resource);

  
  /**

   * platform_get_irq - get an IRQ for a device
   * @dev: platform device
   * @num: IRQ number index

   */
  int platform_get_irq(struct platform_device *dev, unsigned int num)
  {
  	struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);

  	return r ? r->start : -ENXIO;

  }

  EXPORT_SYMBOL_GPL(platform_get_irq);

  
  /**

   * platform_get_resource_byname - get a resource for a device by name
   * @dev: platform device
   * @type: resource type
   * @name: resource name

   */

  struct resource *platform_get_resource_byname(struct platform_device *dev,

  					      unsigned int type,
  					      const char *name)

  {
  	int i;
  
  	for (i = 0; i < dev->num_resources; i++) {
  		struct resource *r = &dev->resource[i];

  		if (type == resource_type(r) && !strcmp(r->name, name))
  			return r;

  	}
  	return NULL;
  }

  EXPORT_SYMBOL_GPL(platform_get_resource_byname);

  
  /**

   * platform_get_irq - get an IRQ for a device
   * @dev: platform device
   * @name: IRQ name

   */

  int platform_get_irq_byname(struct platform_device *dev, const char *name)

  {

  	struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
  							  name);

  	return r ? r->start : -ENXIO;

  }

  EXPORT_SYMBOL_GPL(platform_get_irq_byname);

  
  /**

   * platform_add_devices - add a numbers of platform devices
   * @devs: array of platform devices to add
   * @num: number of platform devices in array

   */
  int platform_add_devices(struct platform_device **devs, int num)
  {
  	int i, ret = 0;
  
  	for (i = 0; i < num; i++) {
  		ret = platform_device_register(devs[i]);
  		if (ret) {
  			while (--i >= 0)
  				platform_device_unregister(devs[i]);
  			break;
  		}
  	}
  
  	return ret;
  }

  EXPORT_SYMBOL_GPL(platform_add_devices);

  struct platform_object {
  	struct platform_device pdev;
  	char name[1];
  };

  /**

   * platform_device_put - destroy a platform device

   * @pdev: platform device to free

   *

   * Free all memory associated with a platform device.  This function must
   * _only_ be externally called in error cases.  All other usage is a bug.

   */
  void platform_device_put(struct platform_device *pdev)
  {
  	if (pdev)
  		put_device(&pdev->dev);
  }
  EXPORT_SYMBOL_GPL(platform_device_put);
  
  static void platform_device_release(struct device *dev)
  {

  	struct platform_object *pa = container_of(dev, struct platform_object,
  						  pdev.dev);

  
  	kfree(pa->pdev.dev.platform_data);
  	kfree(pa->pdev.resource);
  	kfree(pa);
  }
  
  /**

   * platform_device_alloc - create a platform device

   * @name: base name of the device we're adding
   * @id: instance id

   *

   * Create a platform device object which can have other objects attached
   * to it, and which will have attached objects freed when it is released.

   */

  struct platform_device *platform_device_alloc(const char *name, int id)

  {
  	struct platform_object *pa;
  
  	pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
  	if (pa) {
  		strcpy(pa->name, name);
  		pa->pdev.name = pa->name;
  		pa->pdev.id = id;
  		device_initialize(&pa->pdev.dev);
  		pa->pdev.dev.release = platform_device_release;
  	}

  	return pa ? &pa->pdev : NULL;

  }
  EXPORT_SYMBOL_GPL(platform_device_alloc);
  
  /**

   * platform_device_add_resources - add resources to a platform device

   * @pdev: platform device allocated by platform_device_alloc to add resources to
   * @res: set of resources that needs to be allocated for the device
   * @num: number of resources

   *

   * Add a copy of the resources to the platform device.  The memory
   * associated with the resources will be freed when the platform device is
   * released.

   */

  int platform_device_add_resources(struct platform_device *pdev,

  				  const struct resource *res, unsigned int num)

  {
  	struct resource *r;

  	r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);

  	if (r) {

  		pdev->resource = r;
  		pdev->num_resources = num;

  		return 0;

  	}

  	return -ENOMEM;

  }
  EXPORT_SYMBOL_GPL(platform_device_add_resources);
  
  /**

   * platform_device_add_data - add platform-specific data to a platform device

   * @pdev: platform device allocated by platform_device_alloc to add resources to
   * @data: platform specific data for this platform device
   * @size: size of platform specific data

   *

   * Add a copy of platform specific data to the platform device's
   * platform_data pointer.  The memory associated with the platform data
   * will be freed when the platform device is released.

   */

  int platform_device_add_data(struct platform_device *pdev, const void *data,
  			     size_t size)

  {

  	void *d = kmemdup(data, size, GFP_KERNEL);

  	if (d) {

  		pdev->dev.platform_data = d;

  		return 0;

  	}

  	return -ENOMEM;

  }
  EXPORT_SYMBOL_GPL(platform_device_add_data);
  
  /**

   * platform_device_add - add a platform device to device hierarchy
   * @pdev: platform device we're adding

   *

   * This is part 2 of platform_device_register(), though may be called
   * separately _iff_ pdev was allocated by platform_device_alloc().

   */

  int platform_device_add(struct platform_device *pdev)

  {
  	int i, ret = 0;
  
  	if (!pdev)
  		return -EINVAL;
  
  	if (!pdev->dev.parent)
  		pdev->dev.parent = &platform_bus;
  
  	pdev->dev.bus = &platform_bus_type;
  
  	if (pdev->id != -1)

  		dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);

  	else

  		dev_set_name(&pdev->dev, "%s", pdev->name);

  
  	for (i = 0; i < pdev->num_resources; i++) {
  		struct resource *p, *r = &pdev->resource[i];
  
  		if (r->name == NULL)

  			r->name = dev_name(&pdev->dev);

  
  		p = r->parent;
  		if (!p) {

  			if (resource_type(r) == IORESOURCE_MEM)

  				p = &iomem_resource;

  			else if (resource_type(r) == IORESOURCE_IO)

  				p = &ioport_resource;
  		}

  		if (p && insert_resource(p, r)) {

  			printk(KERN_ERR
  			       "%s: failed to claim resource %d
  ",

  			       dev_name(&pdev->dev), i);

  			ret = -EBUSY;
  			goto failed;
  		}
  	}
  
  	pr_debug("Registering platform device '%s'. Parent at %s
  ",

  		 dev_name(&pdev->dev), dev_name(pdev->dev.parent));

  	ret = device_add(&pdev->dev);

  	if (ret == 0)
  		return ret;
  
   failed:

  	while (--i >= 0) {
  		struct resource *r = &pdev->resource[i];
  		unsigned long type = resource_type(r);
  
  		if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
  			release_resource(r);
  	}

  	return ret;
  }

  EXPORT_SYMBOL_GPL(platform_device_add);
  
  /**

   * platform_device_del - remove a platform-level device
   * @pdev: platform device we're removing

   *

   * Note that this function will also release all memory- and port-based
   * resources owned by the device (@dev->resource).  This function must
   * _only_ be externally called in error cases.  All other usage is a bug.

   */

  void platform_device_del(struct platform_device *pdev)

  {
  	int i;
  
  	if (pdev) {

  		device_del(&pdev->dev);

  		for (i = 0; i < pdev->num_resources; i++) {
  			struct resource *r = &pdev->resource[i];

  			unsigned long type = resource_type(r);
  
  			if (type == IORESOURCE_MEM || type == IORESOURCE_IO)

  				release_resource(r);
  		}

  	}
  }

  EXPORT_SYMBOL_GPL(platform_device_del);
  
  /**

   * platform_device_register - add a platform-level device
   * @pdev: platform device we're adding

   */

  int platform_device_register(struct platform_device *pdev)

  {
  	device_initialize(&pdev->dev);
  	return platform_device_add(pdev);
  }

  EXPORT_SYMBOL_GPL(platform_device_register);

  
  /**

   * platform_device_unregister - unregister a platform-level device
   * @pdev: platform device we're unregistering

   *

   * Unregistration is done in 2 steps. First we release all resources
   * and remove it from the subsystem, then we drop reference count by
   * calling platform_device_put().

   */

  void platform_device_unregister(struct platform_device *pdev)

  {
  	platform_device_del(pdev);
  	platform_device_put(pdev);
  }

  EXPORT_SYMBOL_GPL(platform_device_unregister);

  /**

   * platform_device_register_resndata - add a platform-level device with
   * resources and platform-specific data

   *

   * @parent: parent device for the device we're adding
   * @name: base name of the device we're adding
   * @id: instance id

   * @res: set of resources that needs to be allocated for the device
   * @num: number of resources

   * @data: platform specific data for this platform device
   * @size: size of platform specific data
   *

   * Returns &struct platform_device pointer on success, or ERR_PTR() on error.

   */

  struct platform_device *__init_or_module platform_device_register_resndata(

  		struct device *parent,
  		const char *name, int id,

  		const struct resource *res, unsigned int num,

  		const void *data, size_t size)
  {

  	int ret = -ENOMEM;

  	struct platform_device *pdev;

  
  	pdev = platform_device_alloc(name, id);

  	if (!pdev)
  		goto err;

  
  	pdev->dev.parent = parent;

  	if (res) {
  		ret = platform_device_add_resources(pdev, res, num);
  		if (ret)
  			goto err;
  	}
  
  	if (data) {
  		ret = platform_device_add_data(pdev, data, size);
  		if (ret)
  			goto err;

  	}

  	ret = platform_device_add(pdev);
  	if (ret) {
  err:
  		platform_device_put(pdev);
  		return ERR_PTR(ret);
  	}

  
  	return pdev;

  }

  EXPORT_SYMBOL_GPL(platform_device_register_resndata);

  static int platform_drv_probe(struct device *_dev)
  {
  	struct platform_driver *drv = to_platform_driver(_dev->driver);
  	struct platform_device *dev = to_platform_device(_dev);
  
  	return drv->probe(dev);
  }

  static int platform_drv_probe_fail(struct device *_dev)
  {
  	return -ENXIO;
  }

  static int platform_drv_remove(struct device *_dev)
  {
  	struct platform_driver *drv = to_platform_driver(_dev->driver);
  	struct platform_device *dev = to_platform_device(_dev);
  
  	return drv->remove(dev);
  }
  
  static void platform_drv_shutdown(struct device *_dev)
  {
  	struct platform_driver *drv = to_platform_driver(_dev->driver);
  	struct platform_device *dev = to_platform_device(_dev);
  
  	drv->shutdown(dev);
  }

  /**

   * platform_driver_register - register a driver for platform-level devices

   * @drv: platform driver structure

   */
  int platform_driver_register(struct platform_driver *drv)
  {
  	drv->driver.bus = &platform_bus_type;
  	if (drv->probe)
  		drv->driver.probe = platform_drv_probe;
  	if (drv->remove)
  		drv->driver.remove = platform_drv_remove;
  	if (drv->shutdown)
  		drv->driver.shutdown = platform_drv_shutdown;

  	return driver_register(&drv->driver);
  }
  EXPORT_SYMBOL_GPL(platform_driver_register);
  
  /**

   * platform_driver_unregister - unregister a driver for platform-level devices

   * @drv: platform driver structure

   */
  void platform_driver_unregister(struct platform_driver *drv)
  {
  	driver_unregister(&drv->driver);
  }
  EXPORT_SYMBOL_GPL(platform_driver_unregister);

  /**
   * platform_driver_probe - register driver for non-hotpluggable device
   * @drv: platform driver structure
   * @probe: the driver probe routine, probably from an __init section
   *
   * Use this instead of platform_driver_register() when you know the device
   * is not hotpluggable and has already been registered, and you want to
   * remove its run-once probe() infrastructure from memory after the driver
   * has bound to the device.
   *
   * One typical use for this would be with drivers for controllers integrated
   * into system-on-chip processors, where the controller devices have been
   * configured as part of board setup.
   *
   * Returns zero if the driver registered and bound to a device, else returns
   * a negative error code and with the driver not registered.
   */

  int __init_or_module platform_driver_probe(struct platform_driver *drv,

  		int (*probe)(struct platform_device *))
  {
  	int retval, code;

  	/* make sure driver won't have bind/unbind attributes */
  	drv->driver.suppress_bind_attrs = true;

  	/* temporary section violation during probe() */
  	drv->probe = probe;
  	retval = code = platform_driver_register(drv);

  	/*
  	 * Fixup that section violation, being paranoid about code scanning

  	 * the list of drivers in order to probe new devices.  Check to see
  	 * if the probe was successful, and make sure any forced probes of
  	 * new devices fail.
  	 */

  	spin_lock(&platform_bus_type.p->klist_drivers.k_lock);

  	drv->probe = NULL;

  	if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))

  		retval = -ENODEV;
  	drv->driver.probe = platform_drv_probe_fail;

  	spin_unlock(&platform_bus_type.p->klist_drivers.k_lock);

  
  	if (code != retval)
  		platform_driver_unregister(drv);
  	return retval;
  }
  EXPORT_SYMBOL_GPL(platform_driver_probe);

  /**
   * platform_create_bundle - register driver and create corresponding device
   * @driver: platform driver structure
   * @probe: the driver probe routine, probably from an __init section
   * @res: set of resources that needs to be allocated for the device
   * @n_res: number of resources
   * @data: platform specific data for this platform device
   * @size: size of platform specific data
   *
   * Use this in legacy-style modules that probe hardware directly and
   * register a single platform device and corresponding platform driver.

   *
   * Returns &struct platform_device pointer on success, or ERR_PTR() on error.

   */
  struct platform_device * __init_or_module platform_create_bundle(
  			struct platform_driver *driver,
  			int (*probe)(struct platform_device *),
  			struct resource *res, unsigned int n_res,
  			const void *data, size_t size)
  {
  	struct platform_device *pdev;
  	int error;
  
  	pdev = platform_device_alloc(driver->driver.name, -1);
  	if (!pdev) {
  		error = -ENOMEM;
  		goto err_out;
  	}
  
  	if (res) {
  		error = platform_device_add_resources(pdev, res, n_res);
  		if (error)
  			goto err_pdev_put;
  	}
  
  	if (data) {
  		error = platform_device_add_data(pdev, data, size);
  		if (error)
  			goto err_pdev_put;
  	}
  
  	error = platform_device_add(pdev);
  	if (error)
  		goto err_pdev_put;
  
  	error = platform_driver_probe(driver, probe);
  	if (error)
  		goto err_pdev_del;
  
  	return pdev;
  
  err_pdev_del:
  	platform_device_del(pdev);
  err_pdev_put:
  	platform_device_put(pdev);
  err_out:
  	return ERR_PTR(error);
  }
  EXPORT_SYMBOL_GPL(platform_create_bundle);

  /* modalias support enables more hands-off userspace setup:
   * (a) environment variable lets new-style hotplug events work once system is
   *     fully running:  "modprobe $MODALIAS"
   * (b) sysfs attribute lets new-style coldplug recover from hotplug events
   *     mishandled before system is fully running:  "modprobe $(cat modalias)"
   */

  static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
  			     char *buf)

  {
  	struct platform_device	*pdev = to_platform_device(dev);

  	int len = snprintf(buf, PAGE_SIZE, "platform:%s
  ", pdev->name);

  
  	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
  }
  
  static struct device_attribute platform_dev_attrs[] = {
  	__ATTR_RO(modalias),
  	__ATTR_NULL,
  };

  static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)

  {
  	struct platform_device	*pdev = to_platform_device(dev);

  	int rc;
  
  	/* Some devices have extra OF data and an OF-style MODALIAS */
  	rc = of_device_uevent(dev,env);
  	if (rc != -ENODEV)
  		return rc;

  	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
  		(pdev->id_entry) ? pdev->id_entry->name : pdev->name);

  	return 0;
  }

  static const struct platform_device_id *platform_match_id(

  			const struct platform_device_id *id,

  			struct platform_device *pdev)
  {
  	while (id->name[0]) {
  		if (strcmp(pdev->name, id->name) == 0) {
  			pdev->id_entry = id;
  			return id;
  		}
  		id++;
  	}
  	return NULL;
  }

  /**

   * platform_match - bind platform device to platform driver.
   * @dev: device.
   * @drv: driver.

   *

   * Platform device IDs are assumed to be encoded like this:
   * "<name><instance>", where <name> is a short description of the type of
   * device, like "pci" or "floppy", and <instance> is the enumerated
   * instance of the device, like '0' or '42'.  Driver IDs are simply
   * "<name>".  So, extract the <name> from the platform_device structure,
   * and compare it against the name of the driver. Return whether they match
   * or not.

   */

  static int platform_match(struct device *dev, struct device_driver *drv)

  {

  	struct platform_device *pdev = to_platform_device(dev);

  	struct platform_driver *pdrv = to_platform_driver(drv);

  	/* Attempt an OF style match first */
  	if (of_driver_match_device(dev, drv))
  		return 1;
  
  	/* Then try to match against the id table */

  	if (pdrv->id_table)
  		return platform_match_id(pdrv->id_table, pdev) != NULL;

  	/* fall-back to driver name match */

  	return (strcmp(pdev->name, drv->name) == 0);

  }

  #ifdef CONFIG_PM_SLEEP
  
  static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)

  {

  	struct platform_driver *pdrv = to_platform_driver(dev->driver);
  	struct platform_device *pdev = to_platform_device(dev);

  	int ret = 0;

  	if (dev->driver && pdrv->suspend)
  		ret = pdrv->suspend(pdev, mesg);

  
  	return ret;
  }

  static int platform_legacy_resume(struct device *dev)

  {

  	struct platform_driver *pdrv = to_platform_driver(dev->driver);
  	struct platform_device *pdev = to_platform_device(dev);

  	int ret = 0;

  	if (dev->driver && pdrv->resume)
  		ret = pdrv->resume(pdev);

  	return ret;
  }

  static int platform_pm_prepare(struct device *dev)
  {
  	struct device_driver *drv = dev->driver;
  	int ret = 0;
  
  	if (drv && drv->pm && drv->pm->prepare)
  		ret = drv->pm->prepare(dev);
  
  	return ret;
  }
  
  static void platform_pm_complete(struct device *dev)
  {
  	struct device_driver *drv = dev->driver;
  
  	if (drv && drv->pm && drv->pm->complete)
  		drv->pm->complete(dev);
  }

  #else /* !CONFIG_PM_SLEEP */
  
  #define platform_pm_prepare		NULL
  #define platform_pm_complete		NULL
  
  #endif /* !CONFIG_PM_SLEEP */

  #ifdef CONFIG_SUSPEND

  int __weak platform_pm_suspend(struct device *dev)

  {
  	struct device_driver *drv = dev->driver;
  	int ret = 0;

  	if (!drv)
  		return 0;
  
  	if (drv->pm) {

  		if (drv->pm->suspend)
  			ret = drv->pm->suspend(dev);
  	} else {
  		ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
  	}
  
  	return ret;
  }

  int __weak platform_pm_suspend_noirq(struct device *dev)

  {

  	struct device_driver *drv = dev->driver;

  	int ret = 0;

  	if (!drv)

  		return 0;

  	if (drv->pm) {
  		if (drv->pm->suspend_noirq)
  			ret = drv->pm->suspend_noirq(dev);

  	}
  
  	return ret;
  }

  int __weak platform_pm_resume(struct device *dev)

  {
  	struct device_driver *drv = dev->driver;
  	int ret = 0;

  	if (!drv)
  		return 0;
  
  	if (drv->pm) {

  		if (drv->pm->resume)
  			ret = drv->pm->resume(dev);
  	} else {
  		ret = platform_legacy_resume(dev);
  	}
  
  	return ret;
  }

  int __weak platform_pm_resume_noirq(struct device *dev)

  {

  	struct device_driver *drv = dev->driver;

  	int ret = 0;

  	if (!drv)

  		return 0;

  	if (drv->pm) {
  		if (drv->pm->resume_noirq)
  			ret = drv->pm->resume_noirq(dev);

  	}
  
  	return ret;
  }
  
  #else /* !CONFIG_SUSPEND */
  
  #define platform_pm_suspend		NULL
  #define platform_pm_resume		NULL
  #define platform_pm_suspend_noirq	NULL
  #define platform_pm_resume_noirq	NULL
  
  #endif /* !CONFIG_SUSPEND */
  
  #ifdef CONFIG_HIBERNATION
  
  static int platform_pm_freeze(struct device *dev)
  {
  	struct device_driver *drv = dev->driver;
  	int ret = 0;
  
  	if (!drv)
  		return 0;
  
  	if (drv->pm) {
  		if (drv->pm->freeze)
  			ret = drv->pm->freeze(dev);
  	} else {
  		ret = platform_legacy_suspend(dev, PMSG_FREEZE);
  	}
  
  	return ret;
  }
  
  static int platform_pm_freeze_noirq(struct device *dev)
  {

  	struct device_driver *drv = dev->driver;

  	int ret = 0;

  	if (!drv)

  		return 0;

  	if (drv->pm) {
  		if (drv->pm->freeze_noirq)
  			ret = drv->pm->freeze_noirq(dev);

  	}
  
  	return ret;
  }
  
  static int platform_pm_thaw(struct device *dev)
  {
  	struct device_driver *drv = dev->driver;
  	int ret = 0;

  	if (!drv)
  		return 0;
  
  	if (drv->pm) {

  		if (drv->pm->thaw)
  			ret = drv->pm->thaw(dev);
  	} else {
  		ret = platform_legacy_resume(dev);
  	}
  
  	return ret;
  }
  
  static int platform_pm_thaw_noirq(struct device *dev)
  {

  	struct device_driver *drv = dev->driver;

  	int ret = 0;

  	if (!drv)

  		return 0;

  	if (drv->pm) {
  		if (drv->pm->thaw_noirq)
  			ret = drv->pm->thaw_noirq(dev);

  	}
  
  	return ret;
  }
  
  static int platform_pm_poweroff(struct device *dev)
  {
  	struct device_driver *drv = dev->driver;
  	int ret = 0;

  	if (!drv)
  		return 0;
  
  	if (drv->pm) {

  		if (drv->pm->poweroff)
  			ret = drv->pm->poweroff(dev);
  	} else {
  		ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
  	}
  
  	return ret;
  }
  
  static int platform_pm_poweroff_noirq(struct device *dev)
  {

  	struct device_driver *drv = dev->driver;

  	int ret = 0;

  	if (!drv)

  		return 0;

  	if (drv->pm) {
  		if (drv->pm->poweroff_noirq)
  			ret = drv->pm->poweroff_noirq(dev);

  	}
  
  	return ret;
  }
  
  static int platform_pm_restore(struct device *dev)
  {
  	struct device_driver *drv = dev->driver;
  	int ret = 0;

  	if (!drv)
  		return 0;
  
  	if (drv->pm) {

  		if (drv->pm->restore)
  			ret = drv->pm->restore(dev);
  	} else {
  		ret = platform_legacy_resume(dev);
  	}
  
  	return ret;
  }
  
  static int platform_pm_restore_noirq(struct device *dev)
  {

  	struct device_driver *drv = dev->driver;

  	int ret = 0;

  	if (!drv)

  		return 0;

  	if (drv->pm) {
  		if (drv->pm->restore_noirq)
  			ret = drv->pm->restore_noirq(dev);

  	}
  
  	return ret;
  }
  
  #else /* !CONFIG_HIBERNATION */
  
  #define platform_pm_freeze		NULL
  #define platform_pm_thaw		NULL
  #define platform_pm_poweroff		NULL
  #define platform_pm_restore		NULL
  #define platform_pm_freeze_noirq	NULL
  #define platform_pm_thaw_noirq		NULL
  #define platform_pm_poweroff_noirq	NULL
  #define platform_pm_restore_noirq	NULL
  
  #endif /* !CONFIG_HIBERNATION */

  #ifdef CONFIG_PM_RUNTIME
  
  int __weak platform_pm_runtime_suspend(struct device *dev)
  {

  	return pm_generic_runtime_suspend(dev);

  };
  
  int __weak platform_pm_runtime_resume(struct device *dev)
  {

  	return pm_generic_runtime_resume(dev);

  };
  
  int __weak platform_pm_runtime_idle(struct device *dev)
  {

  	return pm_generic_runtime_idle(dev);

  };
  
  #else /* !CONFIG_PM_RUNTIME */
  
  #define platform_pm_runtime_suspend NULL
  #define platform_pm_runtime_resume NULL
  #define platform_pm_runtime_idle NULL
  
  #endif /* !CONFIG_PM_RUNTIME */

  static const struct dev_pm_ops platform_dev_pm_ops = {

  	.prepare = platform_pm_prepare,
  	.complete = platform_pm_complete,
  	.suspend = platform_pm_suspend,
  	.resume = platform_pm_resume,
  	.freeze = platform_pm_freeze,
  	.thaw = platform_pm_thaw,
  	.poweroff = platform_pm_poweroff,
  	.restore = platform_pm_restore,

  	.suspend_noirq = platform_pm_suspend_noirq,
  	.resume_noirq = platform_pm_resume_noirq,
  	.freeze_noirq = platform_pm_freeze_noirq,
  	.thaw_noirq = platform_pm_thaw_noirq,
  	.poweroff_noirq = platform_pm_poweroff_noirq,
  	.restore_noirq = platform_pm_restore_noirq,

  	.runtime_suspend = platform_pm_runtime_suspend,
  	.runtime_resume = platform_pm_runtime_resume,
  	.runtime_idle = platform_pm_runtime_idle,

  };

  struct bus_type platform_bus_type = {
  	.name		= "platform",

  	.dev_attrs	= platform_dev_attrs,

  	.match		= platform_match,

  	.uevent		= platform_uevent,

  	.pm		= &platform_dev_pm_ops,

  };

  EXPORT_SYMBOL_GPL(platform_bus_type);

  
  int __init platform_bus_init(void)
  {

  	int error;

  	early_platform_cleanup();

  	error = device_register(&platform_bus);
  	if (error)
  		return error;
  	error =  bus_register(&platform_bus_type);
  	if (error)
  		device_unregister(&platform_bus);
  	return error;

  }
  
  #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
  u64 dma_get_required_mask(struct device *dev)
  {
  	u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
  	u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
  	u64 mask;
  
  	if (!high_totalram) {
  		/* convert to mask just covering totalram */
  		low_totalram = (1 << (fls(low_totalram) - 1));
  		low_totalram += low_totalram - 1;
  		mask = low_totalram;
  	} else {
  		high_totalram = (1 << (fls(high_totalram) - 1));
  		high_totalram += high_totalram - 1;
  		mask = (((u64)high_totalram) << 32) + 0xffffffff;
  	}

  	return mask;

  }
  EXPORT_SYMBOL_GPL(dma_get_required_mask);
  #endif

  
  static __initdata LIST_HEAD(early_platform_driver_list);
  static __initdata LIST_HEAD(early_platform_device_list);
  
  /**

   * early_platform_driver_register - register early platform driver

   * @epdrv: early_platform driver structure

   * @buf: string passed from early_param()

   *
   * Helper function for early_platform_init() / early_platform_init_buffer()

   */
  int __init early_platform_driver_register(struct early_platform_driver *epdrv,
  					  char *buf)
  {

  	char *tmp;

  	int n;
  
  	/* Simply add the driver to the end of the global list.
  	 * Drivers will by default be put on the list in compiled-in order.
  	 */
  	if (!epdrv->list.next) {
  		INIT_LIST_HEAD(&epdrv->list);
  		list_add_tail(&epdrv->list, &early_platform_driver_list);
  	}
  
  	/* If the user has specified device then make sure the driver
  	 * gets prioritized. The driver of the last device specified on
  	 * command line will be put first on the list.
  	 */
  	n = strlen(epdrv->pdrv->driver.name);
  	if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
  		list_move(&epdrv->list, &early_platform_driver_list);

  		/* Allow passing parameters after device name */
  		if (buf[n] == '\0' || buf[n] == ',')

  			epdrv->requested_id = -1;

  		else {
  			epdrv->requested_id = simple_strtoul(&buf[n + 1],
  							     &tmp, 10);
  
  			if (buf[n] != '.' || (tmp == &buf[n + 1])) {
  				epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
  				n = 0;
  			} else
  				n += strcspn(&buf[n + 1], ",") + 1;
  		}
  
  		if (buf[n] == ',')
  			n++;
  
  		if (epdrv->bufsize) {
  			memcpy(epdrv->buffer, &buf[n],
  			       min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
  			epdrv->buffer[epdrv->bufsize - 1] = '\0';
  		}

  	}
  
  	return 0;
  }
  
  /**

   * early_platform_add_devices - adds a number of early platform devices

   * @devs: array of early platform devices to add
   * @num: number of early platform devices in array

   *
   * Used by early architecture code to register early platform devices and
   * their platform data.

   */
  void __init early_platform_add_devices(struct platform_device **devs, int num)
  {
  	struct device *dev;
  	int i;
  
  	/* simply add the devices to list */
  	for (i = 0; i < num; i++) {
  		dev = &devs[i]->dev;
  
  		if (!dev->devres_head.next) {
  			INIT_LIST_HEAD(&dev->devres_head);
  			list_add_tail(&dev->devres_head,
  				      &early_platform_device_list);
  		}
  	}
  }
  
  /**

   * early_platform_driver_register_all - register early platform drivers

   * @class_str: string to identify early platform driver class

   *
   * Used by architecture code to register all early platform drivers
   * for a certain class. If omitted then only early platform drivers
   * with matching kernel command line class parameters will be registered.

   */
  void __init early_platform_driver_register_all(char *class_str)
  {
  	/* The "class_str" parameter may or may not be present on the kernel
  	 * command line. If it is present then there may be more than one
  	 * matching parameter.
  	 *
  	 * Since we register our early platform drivers using early_param()
  	 * we need to make sure that they also get registered in the case
  	 * when the parameter is missing from the kernel command line.
  	 *
  	 * We use parse_early_options() to make sure the early_param() gets
  	 * called at least once. The early_param() may be called more than
  	 * once since the name of the preferred device may be specified on
  	 * the kernel command line. early_platform_driver_register() handles
  	 * this case for us.
  	 */
  	parse_early_options(class_str);
  }
  
  /**

   * early_platform_match - find early platform device matching driver

   * @epdrv: early platform driver structure

   * @id: id to match against
   */
  static  __init struct platform_device *
  early_platform_match(struct early_platform_driver *epdrv, int id)
  {
  	struct platform_device *pd;
  
  	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
  		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
  			if (pd->id == id)
  				return pd;
  
  	return NULL;
  }
  
  /**

   * early_platform_left - check if early platform driver has matching devices

   * @epdrv: early platform driver structure

   * @id: return true if id or above exists
   */
  static  __init int early_platform_left(struct early_platform_driver *epdrv,
  				       int id)
  {
  	struct platform_device *pd;
  
  	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
  		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
  			if (pd->id >= id)
  				return 1;
  
  	return 0;
  }
  
  /**

   * early_platform_driver_probe_id - probe drivers matching class_str and id

   * @class_str: string to identify early platform driver class
   * @id: id to match against
   * @nr_probe: number of platform devices to successfully probe before exiting
   */
  static int __init early_platform_driver_probe_id(char *class_str,
  						 int id,
  						 int nr_probe)
  {
  	struct early_platform_driver *epdrv;
  	struct platform_device *match;
  	int match_id;
  	int n = 0;
  	int left = 0;
  
  	list_for_each_entry(epdrv, &early_platform_driver_list, list) {
  		/* only use drivers matching our class_str */
  		if (strcmp(class_str, epdrv->class_str))
  			continue;
  
  		if (id == -2) {
  			match_id = epdrv->requested_id;
  			left = 1;
  
  		} else {
  			match_id = id;
  			left += early_platform_left(epdrv, id);
  
  			/* skip requested id */
  			switch (epdrv->requested_id) {
  			case EARLY_PLATFORM_ID_ERROR:
  			case EARLY_PLATFORM_ID_UNSET:
  				break;
  			default:
  				if (epdrv->requested_id == id)
  					match_id = EARLY_PLATFORM_ID_UNSET;
  			}
  		}
  
  		switch (match_id) {
  		case EARLY_PLATFORM_ID_ERROR:
  			pr_warning("%s: unable to parse %s parameter
  ",
  				   class_str, epdrv->pdrv->driver.name);
  			/* fall-through */
  		case EARLY_PLATFORM_ID_UNSET:
  			match = NULL;
  			break;
  		default:
  			match = early_platform_match(epdrv, match_id);
  		}
  
  		if (match) {

  			/*
  			 * Set up a sensible init_name to enable
  			 * dev_name() and others to be used before the
  			 * rest of the driver core is initialized.
  			 */

  			if (!match->dev.init_name && slab_is_available()) {

  				if (match->id != -1)

  					match->dev.init_name =
  						kasprintf(GFP_KERNEL, "%s.%d",
  							  match->name,
  							  match->id);

  				else

  					match->dev.init_name =
  						kasprintf(GFP_KERNEL, "%s",
  							  match->name);

  				if (!match->dev.init_name)
  					return -ENOMEM;
  			}

  			if (epdrv->pdrv->probe(match))
  				pr_warning("%s: unable to probe %s early.
  ",
  					   class_str, match->name);
  			else
  				n++;
  		}
  
  		if (n >= nr_probe)
  			break;
  	}
  
  	if (left)
  		return n;
  	else
  		return -ENODEV;
  }
  
  /**

   * early_platform_driver_probe - probe a class of registered drivers

   * @class_str: string to identify early platform driver class
   * @nr_probe: number of platform devices to successfully probe before exiting
   * @user_only: only probe user specified early platform devices

   *
   * Used by architecture code to probe registered early platform drivers
   * within a certain class. For probe to happen a registered early platform
   * device matching a registered early platform driver is needed.

   */
  int __init early_platform_driver_probe(char *class_str,
  				       int nr_probe,
  				       int user_only)
  {
  	int k, n, i;
  
  	n = 0;
  	for (i = -2; n < nr_probe; i++) {
  		k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
  
  		if (k < 0)
  			break;
  
  		n += k;
  
  		if (user_only)
  			break;
  	}
  
  	return n;
  }
  
  /**
   * early_platform_cleanup - clean up early platform code
   */
  void __init early_platform_cleanup(void)
  {
  	struct platform_device *pd, *pd2;
  
  	/* clean up the devres list used to chain devices */
  	list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
  				 dev.devres_head) {
  		list_del(&pd->dev.devres_head);
  		memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
  	}
  }