drivers/platform/x86/lenovo-ymc.c

   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 ec_trigger __read_mostly;
  24 module_param(ec_trigger, bool, 0444);
  25 MODULE_PARM_DESC(ec_trigger, "Enable EC triggering work-around to force emitting tablet mode events");
  26
  27 static bool force;
  28 module_param(force, bool, 0444);
  29 MODULE_PARM_DESC(force, "Force loading on boards without a convertible DMI chassis-type");
  30
  31 static const struct dmi_system_id ec_trigger_quirk_dmi_table[] = {
  32         {
  33                 /* Lenovo Yoga 7 14ARB7 */
  34                 .matches = {
  35                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
  36                         DMI_MATCH(DMI_PRODUCT_NAME, "82QF"),
  37                 },
  38         },
  39         {
  40                 /* Lenovo Yoga 7 14ACN6 */
  41                 .matches = {
  42                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
  43                         DMI_MATCH(DMI_PRODUCT_NAME, "82N7"),
  44                 },
  45         },
  46         { }
  47 };
  48
  49 static const struct dmi_system_id allowed_chasis_types_dmi_table[] = {
  50         {
  51                 .matches = {
  52                         DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "31" /* Convertible */),
  53                 },
  54         },
  55         {
  56                 .matches = {
  57                         DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "32" /* Detachable */),
  58                 },
  59         },
  60         { }
  61 };
  62
  63 struct lenovo_ymc_private {
  64         struct input_dev *input_dev;
  65         struct acpi_device *ec_acpi_dev;
  66 };
  67
  68 static void lenovo_ymc_trigger_ec(struct wmi_device *wdev, struct lenovo_ymc_private *priv)
  69 {
  70         int err;
  71
  72         if (!priv->ec_acpi_dev)
  73                 return;
  74
  75         err = write_ec_cmd(priv->ec_acpi_dev->handle, VPCCMD_W_YMC, 1);
  76         if (err)
  77                 dev_warn(&wdev->dev, "Could not write YMC: %d\n", err);
  78 }
  79
  80 static const struct key_entry lenovo_ymc_keymap[] = {
  81         /* Laptop */
  82         { KE_SW, 0x01, { .sw = { SW_TABLET_MODE, 0 } } },
  83         /* Tablet */
  84         { KE_SW, 0x02, { .sw = { SW_TABLET_MODE, 1 } } },
  85         /* Drawing Board */
  86         { KE_SW, 0x03, { .sw = { SW_TABLET_MODE, 1 } } },
  87         /* Tent */
  88         { KE_SW, 0x04, { .sw = { SW_TABLET_MODE, 1 } } },
  89         { KE_END },
  90 };
  91
  92 static void lenovo_ymc_notify(struct wmi_device *wdev, union acpi_object *data)
  93 {
  94         struct lenovo_ymc_private *priv = dev_get_drvdata(&wdev->dev);
  95         u32 input_val = 0;
  96         struct acpi_buffer input = { sizeof(input_val), &input_val };
  97         struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
  98         union acpi_object *obj;
  99         acpi_status status;
 100         int code;
 101
 102         status = wmi_evaluate_method(LENOVO_YMC_QUERY_GUID,
 103                                 LENOVO_YMC_QUERY_INSTANCE,
 104                                 LENOVO_YMC_QUERY_METHOD,
 105                                 &input, &output);
 106
 107         if (ACPI_FAILURE(status)) {
 108                 dev_warn(&wdev->dev,
 109                         "Failed to evaluate query method: %s\n",
 110                         acpi_format_exception(status));
 111                 return;
 112         }
 113
 114         obj = output.pointer;
 115
 116         if (obj->type != ACPI_TYPE_INTEGER) {
 117                 dev_warn(&wdev->dev,
 118                         "WMI event data is not an integer\n");
 119                 goto free_obj;
 120         }
 121         code = obj->integer.value;
 122
 123         if (!sparse_keymap_report_event(priv->input_dev, code, 1, true))
 124                 dev_warn(&wdev->dev, "Unknown key %d pressed\n", code);
 125
 126 free_obj:
 127         kfree(obj);
 128         lenovo_ymc_trigger_ec(wdev, priv);
 129 }
 130
 131 static void acpi_dev_put_helper(void *p) { acpi_dev_put(p); }
 132
 133 static int lenovo_ymc_probe(struct wmi_device *wdev, const void *ctx)
 134 {
 135         struct lenovo_ymc_private *priv;
 136         struct input_dev *input_dev;
 137         int err;
 138
 139         if (!dmi_check_system(allowed_chasis_types_dmi_table)) {
 140                 if (force)
 141                         dev_info(&wdev->dev, "Force loading Lenovo YMC support\n");
 142                 else
 143                         return -ENODEV;
 144         }
 145
 146         ec_trigger |= dmi_check_system(ec_trigger_quirk_dmi_table);
 147
 148         priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
 149         if (!priv)
 150                 return -ENOMEM;
 151
 152         if (ec_trigger) {
 153                 pr_debug("Lenovo YMC enable EC triggering.\n");
 154                 priv->ec_acpi_dev = acpi_dev_get_first_match_dev("VPC2004", NULL, -1);
 155
 156                 if (!priv->ec_acpi_dev) {
 157                         dev_err(&wdev->dev, "Could not find EC ACPI device.\n");
 158                         return -ENODEV;
 159                 }
 160                 err = devm_add_action_or_reset(&wdev->dev,
 161                                 acpi_dev_put_helper, priv->ec_acpi_dev);
 162                 if (err) {
 163                         dev_err(&wdev->dev,
 164                                 "Could not clean up EC ACPI device: %d\n", err);
 165                         return err;
 166                 }
 167         }
 168
 169         input_dev = devm_input_allocate_device(&wdev->dev);
 170         if (!input_dev)
 171                 return -ENOMEM;
 172
 173         input_dev->name = "Lenovo Yoga Tablet Mode Control switch";
 174         input_dev->phys = LENOVO_YMC_EVENT_GUID "/input0";
 175         input_dev->id.bustype = BUS_HOST;
 176         input_dev->dev.parent = &wdev->dev;
 177         err = sparse_keymap_setup(input_dev, lenovo_ymc_keymap, NULL);
 178         if (err) {
 179                 dev_err(&wdev->dev,
 180                         "Could not set up input device keymap: %d\n", err);
 181                 return err;
 182         }
 183
 184         err = input_register_device(input_dev);
 185         if (err) {
 186                 dev_err(&wdev->dev,
 187                         "Could not register input device: %d\n", err);
 188                 return err;
 189         }
 190
 191         priv->input_dev = input_dev;
 192         dev_set_drvdata(&wdev->dev, priv);
 193
 194         /* Report the state for the first time on probe */
 195         lenovo_ymc_trigger_ec(wdev, priv);
 196         lenovo_ymc_notify(wdev, NULL);
 197         return 0;
 198 }
 199
 200 static const struct wmi_device_id lenovo_ymc_wmi_id_table[] = {
 201         { .guid_string = LENOVO_YMC_EVENT_GUID },
 202         { }
 203 };
 204 MODULE_DEVICE_TABLE(wmi, lenovo_ymc_wmi_id_table);
 205
 206 static struct wmi_driver lenovo_ymc_driver = {
 207         .driver = {
 208                 .name = "lenovo-ymc",
 209         },
 210         .id_table = lenovo_ymc_wmi_id_table,
 211         .probe = lenovo_ymc_probe,
 212         .notify = lenovo_ymc_notify,
 213 };
 214
 215 module_wmi_driver(lenovo_ymc_driver);
 216
 217 MODULE_AUTHOR("Gergo Koteles <soyer@irl.hu>");
 218 MODULE_DESCRIPTION("Lenovo Yoga Mode Control driver");
 219 MODULE_LICENSE("GPL");