/*
   * RapidIO driver support
   *
   * Copyright 2005 MontaVista Software, Inc.
   * Matt Porter <mporter@kernel.crashing.org>
   *
   * This program is free software; you can redistribute  it and/or modify it
   * under  the terms of  the GNU General  Public License as published by the
   * Free Software Foundation;  either version 2 of the  License, or (at your
   * option) any later version.
   */
  
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/rio.h>
  #include <linux/rio_ids.h>
  
  #include "rio.h"
  
  /**
   *  rio_match_device - Tell if a RIO device has a matching RIO device id structure
   *  @id: the RIO device id structure to match against
   *  @rdev: the RIO device structure to match against
   *
   *  Used from driver probe and bus matching to check whether a RIO device
   *  matches a device id structure provided by a RIO driver. Returns the
   *  matching &struct rio_device_id or %NULL if there is no match.
   */
  static const struct rio_device_id *rio_match_device(const struct rio_device_id
  						    *id,
  						    const struct rio_dev *rdev)
  {
  	while (id->vid || id->asm_vid) {
  		if (((id->vid == RIO_ANY_ID) || (id->vid == rdev->vid)) &&
  		    ((id->did == RIO_ANY_ID) || (id->did == rdev->did)) &&
  		    ((id->asm_vid == RIO_ANY_ID)
  		     || (id->asm_vid == rdev->asm_vid))
  		    && ((id->asm_did == RIO_ANY_ID)
  			|| (id->asm_did == rdev->asm_did)))
  			return id;
  		id++;
  	}
  	return NULL;
  }
  
  /**
   * rio_dev_get - Increments the reference count of the RIO device structure
   *
   * @rdev: RIO device being referenced
   *
   * Each live reference to a device should be refcounted.
   *
   * Drivers for RIO devices should normally record such references in
   * their probe() methods, when they bind to a device, and release
   * them by calling rio_dev_put(), in their disconnect() methods.
   */
  struct rio_dev *rio_dev_get(struct rio_dev *rdev)
  {
  	if (rdev)
  		get_device(&rdev->dev);
  
  	return rdev;
  }
  
  /**
   * rio_dev_put - Release a use of the RIO device structure
   *
   * @rdev: RIO device being disconnected
   *
   * Must be called when a user of a device is finished with it.
   * When the last user of the device calls this function, the
   * memory of the device is freed.
   */
  void rio_dev_put(struct rio_dev *rdev)
  {
  	if (rdev)
  		put_device(&rdev->dev);
  }
  
  /**
   *  rio_device_probe - Tell if a RIO device structure has a matching RIO device id structure
   *  @dev: the RIO device structure to match against
   *
   * return 0 and set rio_dev->driver when drv claims rio_dev, else error
   */
  static int rio_device_probe(struct device *dev)
  {
  	struct rio_driver *rdrv = to_rio_driver(dev->driver);
  	struct rio_dev *rdev = to_rio_dev(dev);
  	int error = -ENODEV;
  	const struct rio_device_id *id;
  
  	if (!rdev->driver && rdrv->probe) {
  		if (!rdrv->id_table)
  			return error;
  		id = rio_match_device(rdrv->id_table, rdev);
  		rio_dev_get(rdev);
  		if (id)
  			error = rdrv->probe(rdev, id);
  		if (error >= 0) {
  			rdev->driver = rdrv;
  			error = 0;
  		} else
  			rio_dev_put(rdev);
  	}
  	return error;
  }
  
  /**
   *  rio_device_remove - Remove a RIO device from the system
   *
   *  @dev: the RIO device structure to match against
   *
   * Remove a RIO device from the system. If it has an associated
   * driver, then run the driver remove() method.  Then update
   * the reference count.
   */
  static int rio_device_remove(struct device *dev)
  {
  	struct rio_dev *rdev = to_rio_dev(dev);
  	struct rio_driver *rdrv = rdev->driver;
  
  	if (rdrv) {
  		if (rdrv->remove)
  			rdrv->remove(rdev);
  		rdev->driver = NULL;
  	}
  
  	rio_dev_put(rdev);
  
  	return 0;
  }
  
  /**
   *  rio_register_driver - register a new RIO driver
   *  @rdrv: the RIO driver structure to register
   *
   *  Adds a &struct rio_driver to the list of registered drivers.
   *  Returns a negative value on error, otherwise 0. If no error
   *  occurred, the driver remains registered even if no device
   *  was claimed during registration.
   */
  int rio_register_driver(struct rio_driver *rdrv)
  {
  	/* initialize common driver fields */
  	rdrv->driver.name = rdrv->name;
  	rdrv->driver.bus = &rio_bus_type;
  
  	/* register with core */
  	return driver_register(&rdrv->driver);
  }
  
  /**
   *  rio_unregister_driver - unregister a RIO driver
   *  @rdrv: the RIO driver structure to unregister
   *
   *  Deletes the &struct rio_driver from the list of registered RIO
   *  drivers, gives it a chance to clean up by calling its remove()
   *  function for each device it was responsible for, and marks those
   *  devices as driverless.
   */
  void rio_unregister_driver(struct rio_driver *rdrv)
  {
  	driver_unregister(&rdrv->driver);
  }
  
  void rio_attach_device(struct rio_dev *rdev)
  {
  	rdev->dev.bus = &rio_bus_type;
  	rdev->dev.parent = &rio_bus;
  }
  EXPORT_SYMBOL_GPL(rio_attach_device);
  
  /**
   *  rio_match_bus - Tell if a RIO device structure has a matching RIO driver device id structure
   *  @dev: the standard device structure to match against
   *  @drv: the standard driver structure containing the ids to match against
   *
   *  Used by a driver to check whether a RIO device present in the
   *  system is in its list of supported devices. Returns 1 if
   *  there is a matching &struct rio_device_id or 0 if there is
   *  no match.
   */
  static int rio_match_bus(struct device *dev, struct device_driver *drv)
  {
  	struct rio_dev *rdev = to_rio_dev(dev);
  	struct rio_driver *rdrv = to_rio_driver(drv);
  	const struct rio_device_id *id = rdrv->id_table;
  	const struct rio_device_id *found_id;
  
  	if (!id)
  		goto out;
  
  	found_id = rio_match_device(id, rdev);
  
  	if (found_id)
  		return 1;
  
        out:return 0;
  }
  
  static int rio_uevent(struct device *dev, struct kobj_uevent_env *env)
  {
  	struct rio_dev *rdev;
  
  	if (!dev)
  		return -ENODEV;
  
  	rdev = to_rio_dev(dev);
  	if (!rdev)
  		return -ENODEV;
  
  	if (add_uevent_var(env, "MODALIAS=rapidio:v%04Xd%04Xav%04Xad%04X",
  			   rdev->vid, rdev->did, rdev->asm_vid, rdev->asm_did))
  		return -ENOMEM;
  	return 0;
  }
  
  struct device rio_bus = {
  	.init_name = "rapidio",
  };
  
  struct bus_type rio_bus_type = {
  	.name = "rapidio",
  	.match = rio_match_bus,
  	.dev_groups = rio_dev_groups,
  	.bus_groups = rio_bus_groups,
  	.probe = rio_device_probe,
  	.remove = rio_device_remove,
  	.uevent	= rio_uevent,
  };
  
  /**
   *  rio_bus_init - Register the RapidIO bus with the device model
   *
   *  Registers the RIO bus device and RIO bus type with the Linux
   *  device model.
   */
  static int __init rio_bus_init(void)
  {
  	if (device_register(&rio_bus) < 0)
  		printk("RIO: failed to register RIO bus device
  ");
  	return bus_register(&rio_bus_type);
  }
  
  postcore_initcall(rio_bus_init);
  
  EXPORT_SYMBOL_GPL(rio_register_driver);
  EXPORT_SYMBOL_GPL(rio_unregister_driver);
  EXPORT_SYMBOL_GPL(rio_bus_type);
  EXPORT_SYMBOL_GPL(rio_dev_get);
  EXPORT_SYMBOL_GPL(rio_dev_put);