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 <[email protected]>
   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 };
  41
  42 static const struct dmi_system_id allowed_chasis_types_dmi_table[] = {
  43         {
  44                 .matches = {
  45                         DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "31" /* Convertible */),
  46                 },
  47         },
  48         {
  49                 .matches = {
  50                         DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "32" /* Detachable */),
  51                 },
  52         },
  53         { }
  54 };
  55
  56 struct lenovo_ymc_private {
  57         struct input_dev *input_dev;
  58         struct acpi_device *ec_acpi_dev;
  59 };
  60
  61 static void lenovo_ymc_trigger_ec(struct wmi_device *wdev, struct lenovo_ymc_private *priv)
  62 {
  63         int err;
  64
  65         if (!priv->ec_acpi_dev)
  66                 return;
  67
  68         err = write_ec_cmd(priv->ec_acpi_dev->handle, VPCCMD_W_YMC, 1);
  69         if (err)
  70                 dev_warn(&wdev->dev, "Could not write YMC: %d\n", err);
  71 }
  72
  73 static const struct key_entry lenovo_ymc_keymap[] = {
  74         /* Laptop */
  75         { KE_SW, 0x01, { .sw = { SW_TABLET_MODE, 0 } } },
  76         /* Tablet */
  77         { KE_SW, 0x02, { .sw = { SW_TABLET_MODE, 1 } } },
  78         /* Drawing Board */
  79         { KE_SW, 0x03, { .sw = { SW_TABLET_MODE, 1 } } },
  80         /* Tent */
  81         { KE_SW, 0x04, { .sw = { SW_TABLET_MODE, 1 } } },
  82         { KE_END },
  83 };
  84
  85 static void lenovo_ymc_notify(struct wmi_device *wdev, union acpi_object *data)
  86 {
  87         struct lenovo_ymc_private *priv = dev_get_drvdata(&wdev->dev);
  88         u32 input_val = 0;
  89         struct acpi_buffer input = { sizeof(input_val), &input_val };
  90         struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
  91         union acpi_object *obj;
  92         acpi_status status;
  93         int code;
  94
  95         status = wmi_evaluate_method(LENOVO_YMC_QUERY_GUID,
  96                                 LENOVO_YMC_QUERY_INSTANCE,
  97                                 LENOVO_YMC_QUERY_METHOD,
  98                                 &input, &output);
  99
 100         if (ACPI_FAILURE(status)) {
 101                 dev_warn(&wdev->dev,
 102                         "Failed to evaluate query method: %s\n",
 103                         acpi_format_exception(status));
 104                 return;
 105         }
 106
 107         obj = output.pointer;
 108
 109         if (obj->type != ACPI_TYPE_INTEGER) {
 110                 dev_warn(&wdev->dev,
 111                         "WMI event data is not an integer\n");
 112                 goto free_obj;
 113         }
 114         code = obj->integer.value;
 115
 116         if (!sparse_keymap_report_event(priv->input_dev, code, 1, true))
 117                 dev_warn(&wdev->dev, "Unknown key %d pressed\n", code);
 118
 119 free_obj:
 120         kfree(obj);
 121         lenovo_ymc_trigger_ec(wdev, priv);
 122 }
 123
 124 static void acpi_dev_put_helper(void *p) { acpi_dev_put(p); }
 125
 126 static int lenovo_ymc_probe(struct wmi_device *wdev, const void *ctx)
 127 {
 128         struct lenovo_ymc_private *priv;
 129         struct input_dev *input_dev;
 130         int err;
 131
 132         if (!dmi_check_system(allowed_chasis_types_dmi_table)) {
 133                 if (force)
 134                         dev_info(&wdev->dev, "Force loading Lenovo YMC support\n");
 135                 else
 136                         return -ENODEV;
 137         }
 138
 139         ec_trigger |= dmi_check_system(ec_trigger_quirk_dmi_table);
 140
 141         priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
 142         if (!priv)
 143                 return -ENOMEM;
 144
 145         if (ec_trigger) {
 146                 pr_debug("Lenovo YMC enable EC triggering.\n");
 147                 priv->ec_acpi_dev = acpi_dev_get_first_match_dev("VPC2004", NULL, -1);
 148
 149                 if (!priv->ec_acpi_dev) {
 150                         dev_err(&wdev->dev, "Could not find EC ACPI device.\n");
 151                         return -ENODEV;
 152                 }
 153                 err = devm_add_action_or_reset(&wdev->dev,
 154                                 acpi_dev_put_helper, priv->ec_acpi_dev);
 155                 if (err) {
 156                         dev_err(&wdev->dev,
 157                                 "Could not clean up EC ACPI device: %d\n", err);
 158                         return err;
 159                 }
 160         }
 161
 162         input_dev = devm_input_allocate_device(&wdev->dev);
 163         if (!input_dev)
 164                 return -ENOMEM;
 165
 166         input_dev->name = "Lenovo Yoga Tablet Mode Control switch";
 167         input_dev->phys = LENOVO_YMC_EVENT_GUID "/input0";
 168         input_dev->id.bustype = BUS_HOST;
 169         input_dev->dev.parent = &wdev->dev;
 170         err = sparse_keymap_setup(input_dev, lenovo_ymc_keymap, NULL);
 171         if (err) {
 172                 dev_err(&wdev->dev,
 173                         "Could not set up input device keymap: %d\n", err);
 174                 return err;
 175         }
 176
 177         err = input_register_device(input_dev);
 178         if (err) {
 179                 dev_err(&wdev->dev,
 180                         "Could not register input device: %d\n", err);
 181                 return err;
 182         }
 183
 184         priv->input_dev = input_dev;
 185         dev_set_drvdata(&wdev->dev, priv);
 186
 187         /* Report the state for the first time on probe */
 188         lenovo_ymc_trigger_ec(wdev, priv);
 189         lenovo_ymc_notify(wdev, NULL);
 190         return 0;
 191 }
 192
 193 static const struct wmi_device_id lenovo_ymc_wmi_id_table[] = {
 194         { .guid_string = LENOVO_YMC_EVENT_GUID },
 195         { }
 196 };
 197 MODULE_DEVICE_TABLE(wmi, lenovo_ymc_wmi_id_table);
 198
 199 static struct wmi_driver lenovo_ymc_driver = {
 200         .driver = {
 201                 .name = "lenovo-ymc",
 202         },
 203         .id_table = lenovo_ymc_wmi_id_table,
 204         .probe = lenovo_ymc_probe,
 205         .notify = lenovo_ymc_notify,
 206 };
 207
 208 module_wmi_driver(lenovo_ymc_driver);
 209
 210 MODULE_AUTHOR("Gergo Koteles <[email protected]>");
 211 MODULE_DESCRIPTION("Lenovo Yoga Mode Control driver");
 212 MODULE_LICENSE("GPL");