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

DEFINITIONS

1. force_power_store
2. intel_wmi_thunderbolt_probe
3. intel_wmi_thunderbolt_remove

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * WMI Thunderbolt driver
   4  *
   5  * Copyright (C) 2017 Dell Inc. All Rights Reserved.
   6  */
   7 
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9 
  10 #include <linux/acpi.h>
  11 #include <linux/device.h>
  12 #include <linux/fs.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/string.h>
  16 #include <linux/sysfs.h>
  17 #include <linux/types.h>
  18 #include <linux/wmi.h>
  19 
  20 #define INTEL_WMI_THUNDERBOLT_GUID "86CCFD48-205E-4A77-9C48-2021CBEDE341"
  21 
  22 static ssize_t force_power_store(struct device *dev,
  23                                  struct device_attribute *attr,
  24                                  const char *buf, size_t count)
  25 {
  26         struct acpi_buffer input;
  27         acpi_status status;
  28         u8 mode;
  29 
  30         input.length = sizeof(u8);
  31         input.pointer = &mode;
  32         mode = hex_to_bin(buf[0]);
  33         dev_dbg(dev, "force_power: storing %#x\n", mode);
  34         if (mode == 0 || mode == 1) {
  35                 status = wmi_evaluate_method(INTEL_WMI_THUNDERBOLT_GUID, 0, 1,
  36                                              &input, NULL);
  37                 if (ACPI_FAILURE(status)) {
  38                         dev_dbg(dev, "force_power: failed to evaluate ACPI method\n");
  39                         return -ENODEV;
  40                 }
  41         } else {
  42                 dev_dbg(dev, "force_power: unsupported mode\n");
  43                 return -EINVAL;
  44         }
  45         return count;
  46 }
  47 
  48 static DEVICE_ATTR_WO(force_power);
  49 
  50 static struct attribute *tbt_attrs[] = {
  51         &dev_attr_force_power.attr,
  52         NULL
  53 };
  54 
  55 static const struct attribute_group tbt_attribute_group = {
  56         .attrs = tbt_attrs,
  57 };
  58 
  59 static int intel_wmi_thunderbolt_probe(struct wmi_device *wdev,
  60                                        const void *context)
  61 {
  62         int ret;
  63 
  64         ret = sysfs_create_group(&wdev->dev.kobj, &tbt_attribute_group);
  65         kobject_uevent(&wdev->dev.kobj, KOBJ_CHANGE);
  66         return ret;
  67 }
  68 
  69 static int intel_wmi_thunderbolt_remove(struct wmi_device *wdev)
  70 {
  71         sysfs_remove_group(&wdev->dev.kobj, &tbt_attribute_group);
  72         kobject_uevent(&wdev->dev.kobj, KOBJ_CHANGE);
  73         return 0;
  74 }
  75 
  76 static const struct wmi_device_id intel_wmi_thunderbolt_id_table[] = {
  77         { .guid_string = INTEL_WMI_THUNDERBOLT_GUID },
  78         { },
  79 };
  80 
  81 static struct wmi_driver intel_wmi_thunderbolt_driver = {
  82         .driver = {
  83                 .name = "intel-wmi-thunderbolt",
  84         },
  85         .probe = intel_wmi_thunderbolt_probe,
  86         .remove = intel_wmi_thunderbolt_remove,
  87         .id_table = intel_wmi_thunderbolt_id_table,
  88 };
  89 
  90 module_wmi_driver(intel_wmi_thunderbolt_driver);
  91 
  92 MODULE_DEVICE_TABLE(wmi, intel_wmi_thunderbolt_id_table);
  93 MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>");
  94 MODULE_DESCRIPTION("Intel WMI Thunderbolt force power driver");
  95 MODULE_LICENSE("GPL v2");