LXR linux/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
  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", 0 },
  43        { },
  44};
  45
  46/* HID I²C Device: 3cdff6f7-4267-4555-ad05-b30a3d8938de */
  47static guid_t i2c_hid_guid =
  48        GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
  49                  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
  50
  51static 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
  73static 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
  80static 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
 117static const struct acpi_device_id i2c_hid_acpi_match[] = {
 118        {"ACPI0C50", 0 },
 119        {"PNP0C50", 0 },
 120        { },
 121};
 122MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
 123
 124static 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
 137module_i2c_driver(i2c_hid_acpi_driver);
 138
 139MODULE_DESCRIPTION("HID over I2C ACPI driver");
 140MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
 141MODULE_LICENSE("GPL");
 142