// SPDX-License-Identifier: GPL-2.0-only

  /*
   * ACPI Hardware Error Device (PNP0C33) Driver
   *
   * Copyright (C) 2010, Intel Corp.
   *	Author: Huang Ying <ying.huang@intel.com>
   *
   * ACPI Hardware Error Device is used to report some hardware errors
   * notified via SCI, mainly the corrected errors.

   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/acpi.h>

  #include <acpi/hed.h>

  static const struct acpi_device_id acpi_hed_ids[] = {

  	{"PNP0C33", 0},
  	{"", 0},
  };
  MODULE_DEVICE_TABLE(acpi, acpi_hed_ids);
  
  static acpi_handle hed_handle;
  
  static BLOCKING_NOTIFIER_HEAD(acpi_hed_notify_list);
  
  int register_acpi_hed_notifier(struct notifier_block *nb)
  {
  	return blocking_notifier_chain_register(&acpi_hed_notify_list, nb);
  }
  EXPORT_SYMBOL_GPL(register_acpi_hed_notifier);
  
  void unregister_acpi_hed_notifier(struct notifier_block *nb)
  {
  	blocking_notifier_chain_unregister(&acpi_hed_notify_list, nb);
  }
  EXPORT_SYMBOL_GPL(unregister_acpi_hed_notifier);
  
  /*
   * SCI to report hardware error is forwarded to the listeners of HED,
   * it is used by HEST Generic Hardware Error Source with notify type
   * SCI.
   */
  static void acpi_hed_notify(struct acpi_device *device, u32 event)
  {
  	blocking_notifier_call_chain(&acpi_hed_notify_list, 0, NULL);
  }

  static int acpi_hed_add(struct acpi_device *device)

  {
  	/* Only one hardware error device */
  	if (hed_handle)
  		return -EINVAL;
  	hed_handle = device->handle;
  	return 0;
  }

  static int acpi_hed_remove(struct acpi_device *device)

  {
  	hed_handle = NULL;
  	return 0;
  }
  
  static struct acpi_driver acpi_hed_driver = {
  	.name = "hardware_error_device",
  	.class = "hardware_error",
  	.ids = acpi_hed_ids,
  	.ops = {
  		.add = acpi_hed_add,
  		.remove = acpi_hed_remove,
  		.notify = acpi_hed_notify,
  	},
  };

  module_acpi_driver(acpi_hed_driver);

  
  ACPI_MODULE_NAME("hed");
  MODULE_AUTHOR("Huang Ying");
  MODULE_DESCRIPTION("ACPI Hardware Error Device Driver");
  MODULE_LICENSE("GPL");