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 void 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 } 74 75 static const struct wmi_device_id intel_wmi_thunderbolt_id_table[] = { 76 { .guid_string = INTEL_WMI_THUNDERBOLT_GUID }, 77 { }, 78 }; 79 80 static struct wmi_driver intel_wmi_thunderbolt_driver = { 81 .driver = { 82 .name = "intel-wmi-thunderbolt", 83 }, 84 .probe = intel_wmi_thunderbolt_probe, 85 .remove = intel_wmi_thunderbolt_remove, 86 .id_table = intel_wmi_thunderbolt_id_table, 87 }; 88 89 module_wmi_driver(intel_wmi_thunderbolt_driver); 90 91 MODULE_DEVICE_TABLE(wmi, intel_wmi_thunderbolt_id_table); 92 MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>"); 93 MODULE_DESCRIPTION("Intel WMI Thunderbolt force power driver"); 94 MODULE_LICENSE("GPL v2"); 95