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", 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
  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
  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
  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, 0);
 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");