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(adev, i2c_hid_acpi_blacklist) == 0)
 64		return -ENODEV;
 65
 66	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 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(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(&client->dev, 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(ihid_acpi->adev);
106
107	return i2c_hid_core_probe(client, &ihid_acpi->ops,
108				  hid_descriptor_address, 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");