drivers/hid/i2c-hid/i2c-hid-acpi.c

   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" },
  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 */
  52 static guid_t i2c_hid_guid =
  53         GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
  54                   0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
  55
  56 static 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
  79 static 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
  86 static 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
 111 static const struct acpi_device_id i2c_hid_acpi_match[] = {
 112         { "ACPI0C50" },
 113         { "PNP0C50" },
 114         { }
 115 };
 116 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 117
 118 static 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
 131 module_i2c_driver(i2c_hid_acpi_driver);
 132
 133 MODULE_DESCRIPTION("HID over I2C ACPI driver");
 134 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
 135 MODULE_LICENSE("GPL");