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
32 struct i2c_hid_acpi {
33 struct i2chid_ops ops;
34 struct acpi_device *adev;
35 };
36
37 static 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", 0 },
43 { },
44 };
45
46 /* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */
47 static guid_t i2c_hid_guid =
48 GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
49 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
50
i2c_hid_acpi_get_descriptor(struct acpi_device * adev)51 static int i2c_hid_acpi_get_descriptor(struct acpi_device *adev)
52 {
53 acpi_handle handle = acpi_device_handle(adev);
54 union acpi_object *obj;
55 u16 hid_descriptor_address;
56
57 if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0)
58 return -ENODEV;
59
60 obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL,
61 ACPI_TYPE_INTEGER);
62 if (!obj) {
63 acpi_handle_err(handle, "Error _DSM call to get HID descriptor address failed\n");
64 return -ENODEV;
65 }
66
67 hid_descriptor_address = obj->integer.value;
68 ACPI_FREE(obj);
69
70 return hid_descriptor_address;
71 }
72
i2c_hid_acpi_shutdown_tail(struct i2chid_ops * ops)73 static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)
74 {
75 struct i2c_hid_acpi *ihid_acpi = container_of(ops, struct i2c_hid_acpi, ops);
76
77 acpi_device_set_power(ihid_acpi->adev, ACPI_STATE_D3_COLD);
78 }
79
i2c_hid_acpi_probe(struct i2c_client * client)80 static int i2c_hid_acpi_probe(struct i2c_client *client)
81 {
82 struct device *dev = &client->dev;
83 struct i2c_hid_acpi *ihid_acpi;
84 struct acpi_device *adev;
85 u16 hid_descriptor_address;
86 int ret;
87
88 adev = ACPI_COMPANION(dev);
89 if (!adev) {
90 dev_err(&client->dev, "Error could not get ACPI device\n");
91 return -ENODEV;
92 }
93
94 ihid_acpi = devm_kzalloc(&client->dev, sizeof(*ihid_acpi), GFP_KERNEL);
95 if (!ihid_acpi)
96 return -ENOMEM;
97
98 ihid_acpi->adev = adev;
99 ihid_acpi->ops.shutdown_tail = i2c_hid_acpi_shutdown_tail;
100
101 ret = i2c_hid_acpi_get_descriptor(adev);
102 if (ret < 0)
103 return ret;
104 hid_descriptor_address = ret;
105
106 acpi_device_fix_up_power(adev);
107
108 if (acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) {
109 device_set_wakeup_capable(dev, true);
110 device_set_wakeup_enable(dev, false);
111 }
112
113 return i2c_hid_core_probe(client, &ihid_acpi->ops,
114 hid_descriptor_address);
115 }
116
117 static const struct acpi_device_id i2c_hid_acpi_match[] = {
118 {"ACPI0C50", 0 },
119 {"PNP0C50", 0 },
120 { },
121 };
122 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
123
124 static struct i2c_driver i2c_hid_acpi_driver = {
125 .driver = {
126 .name = "i2c_hid_acpi",
127 .pm = &i2c_hid_core_pm,
128 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
129 .acpi_match_table = i2c_hid_acpi_match,
130 },
131
132 .probe_new = i2c_hid_acpi_probe,
133 .remove = i2c_hid_core_remove,
134 .shutdown = i2c_hid_core_shutdown,
135 };
136
137 module_i2c_driver(i2c_hid_acpi_driver);
138
139 MODULE_DESCRIPTION("HID over I2C ACPI driver");
140 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
141 MODULE_LICENSE("GPL");
142