1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * lenovo-ymc.c - Lenovo Yoga Mode Control driver 4 * 5 * Copyright © 2022 Gergo Koteles <soyer@irl.hu> 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/acpi.h> 11 #include <linux/dmi.h> 12 #include <linux/input.h> 13 #include <linux/input/sparse-keymap.h> 14 #include <linux/wmi.h> 15 #include "ideapad-laptop.h" 16 17 #define LENOVO_YMC_EVENT_GUID "06129D99-6083-4164-81AD-F092F9D773A6" 18 #define LENOVO_YMC_QUERY_GUID "09B0EE6E-C3FD-4243-8DA1-7911FF80BB8C" 19 20 #define LENOVO_YMC_QUERY_INSTANCE 0 21 #define LENOVO_YMC_QUERY_METHOD 0x01 22 23 static bool force; 24 module_param(force, bool, 0444); 25 MODULE_PARM_DESC(force, "Force loading on boards without a convertible DMI chassis-type"); 26 27 static const struct dmi_system_id allowed_chasis_types_dmi_table[] = { 28 { 29 .matches = { 30 DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "31" /* Convertible */), 31 }, 32 }, 33 { 34 .matches = { 35 DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "32" /* Detachable */), 36 }, 37 }, 38 { } 39 }; 40 41 struct lenovo_ymc_private { 42 struct input_dev *input_dev; 43 }; 44 45 static const struct key_entry lenovo_ymc_keymap[] = { 46 /* Ignore the uninitialized state */ 47 { KE_IGNORE, 0x00 }, 48 /* Laptop */ 49 { KE_SW, 0x01, { .sw = { SW_TABLET_MODE, 0 } } }, 50 /* Tablet */ 51 { KE_SW, 0x02, { .sw = { SW_TABLET_MODE, 1 } } }, 52 /* Drawing Board */ 53 { KE_SW, 0x03, { .sw = { SW_TABLET_MODE, 1 } } }, 54 /* Tent */ 55 { KE_SW, 0x04, { .sw = { SW_TABLET_MODE, 1 } } }, 56 { KE_END }, 57 }; 58 59 static void lenovo_ymc_notify(struct wmi_device *wdev, union acpi_object *data) 60 { 61 struct lenovo_ymc_private *priv = dev_get_drvdata(&wdev->dev); 62 u32 input_val = 0; 63 struct acpi_buffer input = { sizeof(input_val), &input_val }; 64 struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL }; 65 union acpi_object *obj; 66 acpi_status status; 67 int code; 68 69 status = wmi_evaluate_method(LENOVO_YMC_QUERY_GUID, 70 LENOVO_YMC_QUERY_INSTANCE, 71 LENOVO_YMC_QUERY_METHOD, 72 &input, &output); 73 74 if (ACPI_FAILURE(status)) { 75 dev_warn(&wdev->dev, 76 "Failed to evaluate query method: %s\n", 77 acpi_format_exception(status)); 78 return; 79 } 80 81 obj = output.pointer; 82 83 if (obj->type != ACPI_TYPE_INTEGER) { 84 dev_warn(&wdev->dev, 85 "WMI event data is not an integer\n"); 86 goto free_obj; 87 } 88 code = obj->integer.value; 89 90 if (!sparse_keymap_report_event(priv->input_dev, code, 1, true)) 91 dev_warn(&wdev->dev, "Unknown key %d pressed\n", code); 92 93 free_obj: 94 kfree(obj); 95 ideapad_laptop_call_notifier(IDEAPAD_LAPTOP_YMC_EVENT, &code); 96 } 97 98 static int lenovo_ymc_probe(struct wmi_device *wdev, const void *ctx) 99 { 100 struct lenovo_ymc_private *priv; 101 struct input_dev *input_dev; 102 int err; 103 104 if (!dmi_check_system(allowed_chasis_types_dmi_table)) { 105 if (force) 106 dev_info(&wdev->dev, "Force loading Lenovo YMC support\n"); 107 else 108 return -ENODEV; 109 } 110 111 priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL); 112 if (!priv) 113 return -ENOMEM; 114 115 input_dev = devm_input_allocate_device(&wdev->dev); 116 if (!input_dev) 117 return -ENOMEM; 118 119 input_dev->name = "Lenovo Yoga Tablet Mode Control switch"; 120 input_dev->phys = LENOVO_YMC_EVENT_GUID "/input0"; 121 input_dev->id.bustype = BUS_HOST; 122 input_dev->dev.parent = &wdev->dev; 123 err = sparse_keymap_setup(input_dev, lenovo_ymc_keymap, NULL); 124 if (err) { 125 dev_err(&wdev->dev, 126 "Could not set up input device keymap: %d\n", err); 127 return err; 128 } 129 130 err = input_register_device(input_dev); 131 if (err) { 132 dev_err(&wdev->dev, 133 "Could not register input device: %d\n", err); 134 return err; 135 } 136 137 priv->input_dev = input_dev; 138 dev_set_drvdata(&wdev->dev, priv); 139 140 /* Report the state for the first time on probe */ 141 lenovo_ymc_notify(wdev, NULL); 142 return 0; 143 } 144 145 static const struct wmi_device_id lenovo_ymc_wmi_id_table[] = { 146 { .guid_string = LENOVO_YMC_EVENT_GUID }, 147 { } 148 }; 149 MODULE_DEVICE_TABLE(wmi, lenovo_ymc_wmi_id_table); 150 151 static struct wmi_driver lenovo_ymc_driver = { 152 .driver = { 153 .name = "lenovo-ymc", 154 }, 155 .id_table = lenovo_ymc_wmi_id_table, 156 .probe = lenovo_ymc_probe, 157 .notify = lenovo_ymc_notify, 158 }; 159 160 module_wmi_driver(lenovo_ymc_driver); 161 162 MODULE_AUTHOR("Gergo Koteles <soyer@irl.hu>"); 163 MODULE_DESCRIPTION("Lenovo Yoga Mode Control driver"); 164 MODULE_LICENSE("GPL"); 165 MODULE_IMPORT_NS(IDEAPAD_LAPTOP); 166