1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * ACPI Hardware Error Device (PNP0C33) Driver
4 *
5 * Copyright (C) 2010, Intel Corp.
6 *	Author: Huang Ying <ying.huang@intel.com>
7 *
8 * ACPI Hardware Error Device is used to report some hardware errors
9 * notified via SCI, mainly the corrected errors.
10 */
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/acpi.h>
16#include <acpi/hed.h>
17
18static const struct acpi_device_id acpi_hed_ids[] = {
19	{"PNP0C33", 0},
20	{"", 0},
21};
22MODULE_DEVICE_TABLE(acpi, acpi_hed_ids);
23
24static acpi_handle hed_handle;
25
26static BLOCKING_NOTIFIER_HEAD(acpi_hed_notify_list);
27
28int register_acpi_hed_notifier(struct notifier_block *nb)
29{
30	return blocking_notifier_chain_register(&acpi_hed_notify_list, nb);
31}
32EXPORT_SYMBOL_GPL(register_acpi_hed_notifier);
33
34void unregister_acpi_hed_notifier(struct notifier_block *nb)
35{
36	blocking_notifier_chain_unregister(&acpi_hed_notify_list, nb);
37}
38EXPORT_SYMBOL_GPL(unregister_acpi_hed_notifier);
39
40/*
41 * SCI to report hardware error is forwarded to the listeners of HED,
42 * it is used by HEST Generic Hardware Error Source with notify type
43 * SCI.
44 */
45static void acpi_hed_notify(acpi_handle handle, u32 event, void *data)
46{
47	blocking_notifier_call_chain(&acpi_hed_notify_list, 0, NULL);
48}
49
50static int acpi_hed_add(struct acpi_device *device)
51{
52	int err;
53
54	/* Only one hardware error device */
55	if (hed_handle)
56		return -EINVAL;
57	hed_handle = device->handle;
58
59	err = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
60					      acpi_hed_notify, device);
61	if (err)
62		hed_handle = NULL;
63
64	return err;
65}
66
67static void acpi_hed_remove(struct acpi_device *device)
68{
69	acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY,
70				       acpi_hed_notify);
71	hed_handle = NULL;
72}
73
74static struct acpi_driver acpi_hed_driver = {
75	.name = "hardware_error_device",
76	.class = "hardware_error",
77	.ids = acpi_hed_ids,
78	.ops = {
79		.add = acpi_hed_add,
80		.remove = acpi_hed_remove,
81	},
82};
83module_acpi_driver(acpi_hed_driver);
84
85MODULE_AUTHOR("Huang Ying");
86MODULE_DESCRIPTION("ACPI Hardware Error Device Driver");
87MODULE_LICENSE("GPL");
88