drivers/platform/x86/intel-wmi-thunderbolt.c

   1 /*
   2  * WMI Thunderbolt driver
   3  *
   4  * Copyright (C) 2017 Dell Inc. All Rights Reserved.
   5  *
   6  *  This program is free software; you can redistribute it and/or modify it
   7  *  under the terms of the GNU General Public License version 2 as published
   8  *  by the Free Software Foundation.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  */
  15
  16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18 #include <linux/acpi.h>
  19 #include <linux/device.h>
  20 #include <linux/fs.h>
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/string.h>
  24 #include <linux/sysfs.h>
  25 #include <linux/types.h>
  26 #include <linux/wmi.h>
  27
  28 #define INTEL_WMI_THUNDERBOLT_GUID "86CCFD48-205E-4A77-9C48-2021CBEDE341"
  29
  30 static ssize_t force_power_store(struct device *dev,
  31                                  struct device_attribute *attr,
  32                                  const char *buf, size_t count)
  33 {
  34         struct acpi_buffer input;
  35         acpi_status status;
  36         u8 mode;
  37
  38         input.length = sizeof(u8);
  39         input.pointer = &mode;
  40         mode = hex_to_bin(buf[0]);
  41         if (mode == 0 || mode == 1) {
  42                 status = wmi_evaluate_method(INTEL_WMI_THUNDERBOLT_GUID, 0, 1,
  43                                              &input, NULL);
  44                 if (ACPI_FAILURE(status))
  45                         return -ENODEV;
  46         } else {
  47                 return -EINVAL;
  48         }
  49         return count;
  50 }
  51
  52 static DEVICE_ATTR_WO(force_power);
  53
  54 static struct attribute *tbt_attrs[] = {
  55         &dev_attr_force_power.attr,
  56         NULL
  57 };
  58
  59 static const struct attribute_group tbt_attribute_group = {
  60         .attrs = tbt_attrs,
  61 };
  62
  63 static int intel_wmi_thunderbolt_probe(struct wmi_device *wdev)
  64 {
  65         int ret;
  66
  67         ret = sysfs_create_group(&wdev->dev.kobj, &tbt_attribute_group);
  68         kobject_uevent(&wdev->dev.kobj, KOBJ_CHANGE);
  69         return ret;
  70 }
  71
  72 static int intel_wmi_thunderbolt_remove(struct wmi_device *wdev)
  73 {
  74         sysfs_remove_group(&wdev->dev.kobj, &tbt_attribute_group);
  75         kobject_uevent(&wdev->dev.kobj, KOBJ_CHANGE);
  76         return 0;
  77 }
  78
  79 static const struct wmi_device_id intel_wmi_thunderbolt_id_table[] = {
  80         { .guid_string = INTEL_WMI_THUNDERBOLT_GUID },
  81         { },
  82 };
  83
  84 static struct wmi_driver intel_wmi_thunderbolt_driver = {
  85         .driver = {
  86                 .name = "intel-wmi-thunderbolt",
  87         },
  88         .probe = intel_wmi_thunderbolt_probe,
  89         .remove = intel_wmi_thunderbolt_remove,
  90         .id_table = intel_wmi_thunderbolt_id_table,
  91 };
  92
  93 module_wmi_driver(intel_wmi_thunderbolt_driver);
  94
  95 MODULE_ALIAS("wmi:" INTEL_WMI_THUNDERBOLT_GUID);
  96 MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>");
  97 MODULE_DESCRIPTION("Intel WMI Thunderbolt force power driver");
  98 MODULE_LICENSE("GPL");