1/*
2 * HID over I2C ACPI Subclass
3 *
4 * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
5 * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
6 * Copyright (c) 2012 Red Hat, Inc
7 *
8 * This code was forked out of the core code, which was partly based on
9 * "USB HID support for Linux":
10 *
11 * Copyright (c) 1999 Andreas Gal
12 * Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
13 * Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
14 * Copyright (c) 2007-2008 Oliver Neukum
15 * Copyright (c) 2006-2010 Jiri Kosina
16 *
17 * This file is subject to the terms and conditions of the GNU General Public
18 * License. See the file COPYING in the main directory of this archive for
19 * more details.
20 */
21
22#include <linux/acpi.h>
23#include <linux/device.h>
24#include <linux/i2c.h>
25#include <linux/kernel.h>
26#include <linux/module.h>
27#include <linux/pm.h>
28#include <linux/uuid.h>
29
30#include "i2c-hid.h"
31
32struct i2c_hid_acpi {
33 struct i2chid_ops ops;
34 struct acpi_device *adev;
35};
36
37static const struct acpi_device_id i2c_hid_acpi_blacklist[] = {
38 /*
39 * The CHPN0001 ACPI device, which is used to describe the Chipone
40 * ICN8505 controller, has a _CID of PNP0C50 but is not HID compatible.
41 */
42 { "CHPN0001" },
43 /*
44 * The IDEA5002 ACPI device causes high interrupt usage and spurious
45 * wakeups from suspend.
46 */
47 { "IDEA5002" },
48 { }
49};
50
51/* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */
52static guid_t i2c_hid_guid =
53 GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
54 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
55
56static int i2c_hid_acpi_get_descriptor(struct i2c_hid_acpi *ihid_acpi)
57{
58 struct acpi_device *adev = ihid_acpi->adev;
59 acpi_handle handle = acpi_device_handle(adev);
60 union acpi_object *obj;
61 u16 hid_descriptor_address;
62
63 if (acpi_match_device_ids(device: adev, ids: i2c_hid_acpi_blacklist) == 0)
64 return -ENODEV;
65
66 obj = acpi_evaluate_dsm_typed(handle, guid: &i2c_hid_guid, rev: 1, func: 1, NULL,
67 ACPI_TYPE_INTEGER);
68 if (!obj) {
69 acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n");
70 return -ENODEV;
71 }
72
73 hid_descriptor_address = obj->integer.value;
74 ACPI_FREE(obj);
75
76 return hid_descriptor_address;
77}
78
79static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)
80{
81 struct i2c_hid_acpi *ihid_acpi = container_of(ops, struct i2c_hid_acpi, ops);
82
83 acpi_device_set_power(device: ihid_acpi->adev, ACPI_STATE_D3_COLD);
84}
85
86static int i2c_hid_acpi_probe(struct i2c_client *client)
87{
88 struct device *dev = &client->dev;
89 struct i2c_hid_acpi *ihid_acpi;
90 u16 hid_descriptor_address;
91 int ret;
92
93 ihid_acpi = devm_kzalloc(dev: &client->dev, size: sizeof(*ihid_acpi), GFP_KERNEL);
94 if (!ihid_acpi)
95 return -ENOMEM;
96
97 ihid_acpi->adev = ACPI_COMPANION(dev);
98 ihid_acpi->ops.shutdown_tail = i2c_hid_acpi_shutdown_tail;
99
100 ret = i2c_hid_acpi_get_descriptor(ihid_acpi);
101 if (ret < 0)
102 return ret;
103 hid_descriptor_address = ret;
104
105 acpi_device_fix_up_power(device: ihid_acpi->adev);
106
107 return i2c_hid_core_probe(client, ops: &ihid_acpi->ops,
108 hid_descriptor_address, quirks: 0);
109}
110
111static const struct acpi_device_id i2c_hid_acpi_match[] = {
112 { "ACPI0C50" },
113 { "PNP0C50" },
114 { }
115};
116MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
117
118static struct i2c_driver i2c_hid_acpi_driver = {
119 .driver = {
120 .name = "i2c_hid_acpi",
121 .pm = &i2c_hid_core_pm,
122 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
123 .acpi_match_table = i2c_hid_acpi_match,
124 },
125
126 .probe = i2c_hid_acpi_probe,
127 .remove = i2c_hid_core_remove,
128 .shutdown = i2c_hid_core_shutdown,
129};
130
131module_i2c_driver(i2c_hid_acpi_driver);
132
133MODULE_DESCRIPTION("HID over I2C ACPI driver");
134MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
135MODULE_LICENSE("GPL");
136

source code of linux/drivers/hid/i2c-hid/i2c-hid-acpi.c