--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * lg-laptop.c - LG Gram ACPI features and hotkeys Driver
+ *
+ * Copyright (C) 2018 Matan Ziv-Av <matan@svgalib.org>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/acpi.h>
+#include <linux/input.h>
+#include <linux/input/sparse-keymap.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+#define LED_DEVICE(_name, max) struct led_classdev _name = { \
+       .name           = __stringify(_name),   \
+       .max_brightness = max,                  \
+       .brightness_set = _name##_set,          \
+       .brightness_get = _name##_get,          \
+}
+
+MODULE_AUTHOR("Matan Ziv-Av");
+MODULE_DESCRIPTION("LG WMI Hotkey Driver");
+MODULE_LICENSE("GPL");
+
+#define WMI_EVENT_GUID0        "E4FB94F9-7F2B-4173-AD1A-CD1D95086248"
+#define WMI_EVENT_GUID1        "023B133E-49D1-4E10-B313-698220140DC2"
+#define WMI_EVENT_GUID2        "37BE1AC0-C3F2-4B1F-BFBE-8FDEAF2814D6"
+#define WMI_EVENT_GUID3        "911BAD44-7DF8-4FBB-9319-BABA1C4B293B"
+#define WMI_METHOD_WMAB "C3A72B38-D3EF-42D3-8CBB-D5A57049F66D"
+#define WMI_METHOD_WMBB "2B4F501A-BD3C-4394-8DCF-00A7D2BC8210"
+#define WMI_EVENT_GUID  WMI_EVENT_GUID0
+
+#define WMAB_METHOD     "\\XINI.WMAB"
+#define WMBB_METHOD     "\\XINI.WMBB"
+#define SB_GGOV_METHOD  "\\_SB.GGOV"
+#define GOV_TLED        0x2020008
+#define WM_GET          1
+#define WM_SET          2
+#define WM_KEY_LIGHT    0x400
+#define WM_TLED         0x404
+#define WM_FN_LOCK      0x407
+#define WM_BATT_LIMIT   0x61
+#define WM_READER_MODE  0xBF
+#define WM_FAN_MODE    0x33
+#define WMBB_USB_CHARGE 0x10B
+#define WMBB_BATT_LIMIT 0x10C
+
+#define PLATFORM_NAME   "lg-laptop"
+
+MODULE_ALIAS("wmi:" WMI_EVENT_GUID0);
+MODULE_ALIAS("wmi:" WMI_EVENT_GUID1);
+MODULE_ALIAS("wmi:" WMI_EVENT_GUID2);
+MODULE_ALIAS("wmi:" WMI_EVENT_GUID3);
+MODULE_ALIAS("wmi:" WMI_METHOD_WMAB);
+MODULE_ALIAS("wmi:" WMI_METHOD_WMBB);
+MODULE_ALIAS("acpi*:LGEX0815:*");
+
+static struct platform_device *pf_device;
+static struct input_dev *wmi_input_dev;
+
+static u32 inited;
+#define INIT_INPUT_WMI_0        0x01
+#define INIT_INPUT_WMI_2        0x02
+#define INIT_INPUT_ACPI         0x04
+#define INIT_TPAD_LED           0x08
+#define INIT_KBD_LED            0x10
+#define INIT_SPARSE_KEYMAP        0x80
+
+static const struct key_entry wmi_keymap[] = {
+       {KE_KEY, 0x70, {KEY_F15} },      /* LG control panel (F1) */
+       {KE_KEY, 0x74, {KEY_F13} },      /* Touchpad toggle (F5) */
+       {KE_KEY, 0xf020000, {KEY_F14} }, /* Read mode (F9) */
+       {KE_KEY, 0x10000000, {KEY_F16} },/* Keyboard backlight (F8) - pressing
+                                         * this key both sends an event and
+                                         * changes backlight level.
+                                         */
+       {KE_KEY, 0x80, {KEY_RFKILL} },
+       {KE_END, 0}
+};
+
+static int ggov(u32 arg0)
+{
+       union acpi_object args[1];
+       union acpi_object *r;
+       acpi_status status;
+       acpi_handle handle;
+       struct acpi_object_list arg;
+       struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+       int res;
+
+       args[0].type = ACPI_TYPE_INTEGER;
+       args[0].integer.value = arg0;
+
+       status = acpi_get_handle(NULL, (acpi_string) SB_GGOV_METHOD, &handle);
+       if (ACPI_FAILURE(status)) {
+               pr_err("Cannot get handle");
+               return -ENODEV;
+       }
+
+       arg.count = 1;
+       arg.pointer = args;
+
+       status = acpi_evaluate_object(handle, NULL, &arg, &buffer);
+       if (ACPI_FAILURE(status)) {
+               acpi_handle_err(handle, "GGOV: call failed.\n");
+               return -EINVAL;
+       }
+
+       r = buffer.pointer;
+       if (r->type != ACPI_TYPE_INTEGER) {
+               kfree(r);
+               return -EINVAL;
+       }
+
+       res = r->integer.value;
+       kfree(r);
+
+       return res;
+}
+
+static union acpi_object *lg_wmab(u32 method, u32 arg1, u32 arg2)
+{
+       union acpi_object args[3];
+       acpi_status status;
+       acpi_handle handle;
+       struct acpi_object_list arg;
+       struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+
+       args[0].type = ACPI_TYPE_INTEGER;
+       args[0].integer.value = method;
+       args[1].type = ACPI_TYPE_INTEGER;
+       args[1].integer.value = arg1;
+       args[2].type = ACPI_TYPE_INTEGER;
+       args[2].integer.value = arg2;
+
+       status = acpi_get_handle(NULL, (acpi_string) WMAB_METHOD, &handle);
+       if (ACPI_FAILURE(status)) {
+               pr_err("Cannot get handle");
+               return NULL;
+       }
+
+       arg.count = 3;
+       arg.pointer = args;
+
+       status = acpi_evaluate_object(handle, NULL, &arg, &buffer);
+       if (ACPI_FAILURE(status)) {
+               acpi_handle_err(handle, "WMAB: call failed.\n");
+               return NULL;
+       }
+
+       return buffer.pointer;
+}
+
+static union acpi_object *lg_wmbb(u32 method_id, u32 arg1, u32 arg2)
+{
+       union acpi_object args[3];
+       acpi_status status;
+       acpi_handle handle;
+       struct acpi_object_list arg;
+       struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+       u8 buf[32];
+
+       *(u32 *)buf = method_id;
+       *(u32 *)(buf + 4) = arg1;
+       *(u32 *)(buf + 16) = arg2;
+       args[0].type = ACPI_TYPE_INTEGER;
+       args[0].integer.value = 0; /* ignored */
+       args[1].type = ACPI_TYPE_INTEGER;
+       args[1].integer.value = 1; /* Must be 1 or 2. Does not matter which */
+       args[2].type = ACPI_TYPE_BUFFER;
+       args[2].buffer.length = 32;
+       args[2].buffer.pointer = buf;
+
+       status = acpi_get_handle(NULL, (acpi_string)WMBB_METHOD, &handle);
+       if (ACPI_FAILURE(status)) {
+               pr_err("Cannot get handle");
+               return NULL;
+       }
+
+       arg.count = 3;
+       arg.pointer = args;
+
+       status = acpi_evaluate_object(handle, NULL, &arg, &buffer);
+       if (ACPI_FAILURE(status)) {
+               acpi_handle_err(handle, "WMAB: call failed.\n");
+               return NULL;
+       }
+
+       return (union acpi_object *)buffer.pointer;
+}
+
+static void wmi_notify(u32 value, void *context)
+{
+       struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
+       union acpi_object *obj;
+       acpi_status status;
+       long data = (long)context;
+
+       pr_debug("event guid %li\n", data);
+       status = wmi_get_event_data(value, &response);
+       if (ACPI_FAILURE(status)) {
+               pr_err("Bad event status 0x%x\n", status);
+               return;
+       }
+
+       obj = (union acpi_object *)response.pointer;
+       if (!obj)
+               return;
+
+       if (obj->type == ACPI_TYPE_INTEGER) {
+               int eventcode = obj->integer.value;
+               struct key_entry *key;
+
+               key =
+                   sparse_keymap_entry_from_scancode(wmi_input_dev, eventcode);
+               if (key && key->type == KE_KEY)
+                       sparse_keymap_report_entry(wmi_input_dev, key, 1, true);
+       }
+
+       pr_debug("Type: %i    Eventcode: 0x%llx\n", obj->type,
+                obj->integer.value);
+       kfree(response.pointer);
+}
+
+static void wmi_input_setup(void)
+{
+       acpi_status status;
+
+       wmi_input_dev = input_allocate_device();
+       if (wmi_input_dev) {
+               wmi_input_dev->name = "LG WMI hotkeys";
+               wmi_input_dev->phys = "wmi/input0";
+               wmi_input_dev->id.bustype = BUS_HOST;
+
+               if (sparse_keymap_setup(wmi_input_dev, wmi_keymap, NULL) ||
+                   input_register_device(wmi_input_dev)) {
+                       pr_info("Cannot initialize input device");
+                       input_free_device(wmi_input_dev);
+                       return;
+               }
+
+               inited |= INIT_SPARSE_KEYMAP;
+               status = wmi_install_notify_handler(WMI_EVENT_GUID0, wmi_notify,
+                                                   (void *)0);
+               if (ACPI_SUCCESS(status))
+                       inited |= INIT_INPUT_WMI_0;
+
+               status = wmi_install_notify_handler(WMI_EVENT_GUID2, wmi_notify,
+                                                   (void *)2);
+               if (ACPI_SUCCESS(status))
+                       inited |= INIT_INPUT_WMI_2;
+       } else {
+               pr_info("Cannot allocate input device");
+       }
+}
+
+static void acpi_notify(struct acpi_device *device, u32 event)
+{
+       struct key_entry *key;
+
+       acpi_handle_debug(device->handle, "notify: %d\n", event);
+       if (inited & INIT_SPARSE_KEYMAP) {
+               key = sparse_keymap_entry_from_scancode(wmi_input_dev, 0x80);
+               if (key && key->type == KE_KEY)
+                       sparse_keymap_report_entry(wmi_input_dev, key, 1, true);
+       }
+}
+
+static ssize_t fan_mode_store(struct device *dev,
+                             struct device_attribute *attr,
+                             const char *buffer, size_t count)
+{
+       bool value;
+       union acpi_object *r;
+       u32 m;
+       int ret;
+
+       ret = kstrtobool(buffer, &value);
+       if (ret)
+               return ret;
+
+       r = lg_wmab(WM_FAN_MODE, WM_GET, 0);
+       if (!r)
+               return -EIO;
+
+       if (r->type != ACPI_TYPE_INTEGER) {
+               kfree(r);
+               return -EIO;
+       }
+
+       m = r->integer.value;
+       kfree(r);
+       r = lg_wmab(WM_FAN_MODE, WM_SET, (m & 0xffffff0f) | (value << 4));
+       kfree(r);
+       r = lg_wmab(WM_FAN_MODE, WM_SET, (m & 0xfffffff0) | value);
+       kfree(r);
+
+       return count;
+}
+
+static ssize_t fan_mode_show(struct device *dev,
+                            struct device_attribute *attr, char *buffer)
+{
+       unsigned int status;
+       union acpi_object *r;
+
+       r = lg_wmab(WM_FAN_MODE, WM_GET, 0);
+       if (!r)
+               return -EIO;
+
+       if (r->type != ACPI_TYPE_INTEGER) {
+               kfree(r);
+               return -EIO;
+       }
+
+       status = r->integer.value & 0x01;
+       kfree(r);
+
+       return snprintf(buffer, PAGE_SIZE, "%d\n", status);
+}
+
+static ssize_t usb_charge_store(struct device *dev,
+                               struct device_attribute *attr,
+                               const char *buffer, size_t count)
+{
+       bool value;
+       union acpi_object *r;
+       int ret;
+
+       ret = kstrtobool(buffer, &value);
+       if (ret)
+               return ret;
+
+       r = lg_wmbb(WMBB_USB_CHARGE, WM_SET, value);
+       if (!r)
+               return -EIO;
+
+       kfree(r);
+       return count;
+}
+
+static ssize_t usb_charge_show(struct device *dev,
+                              struct device_attribute *attr, char *buffer)
+{
+       unsigned int status;
+       union acpi_object *r;
+
+       r = lg_wmbb(WMBB_USB_CHARGE, WM_GET, 0);
+       if (!r)
+               return -EIO;
+
+       if (r->type != ACPI_TYPE_BUFFER) {
+               kfree(r);
+               return -EIO;
+       }
+
+       status = !!r->buffer.pointer[0x10];
+
+       kfree(r);
+
+       return snprintf(buffer, PAGE_SIZE, "%d\n", status);
+}
+
+static ssize_t reader_mode_store(struct device *dev,
+                                struct device_attribute *attr,
+                                const char *buffer, size_t count)
+{
+       bool value;
+       union acpi_object *r;
+       int ret;
+
+       ret = kstrtobool(buffer, &value);
+       if (ret)
+               return ret;
+
+       r = lg_wmab(WM_READER_MODE, WM_SET, value);
+       if (!r)
+               return -EIO;
+
+       kfree(r);
+       return count;
+}
+
+static ssize_t reader_mode_show(struct device *dev,
+                               struct device_attribute *attr, char *buffer)
+{
+       unsigned int status;
+       union acpi_object *r;
+
+       r = lg_wmab(WM_READER_MODE, WM_GET, 0);
+       if (!r)
+               return -EIO;
+
+       if (r->type != ACPI_TYPE_INTEGER) {
+               kfree(r);
+               return -EIO;
+       }
+
+       status = !!r->integer.value;
+
+       kfree(r);
+
+       return snprintf(buffer, PAGE_SIZE, "%d\n", status);
+}
+
+static ssize_t fn_lock_store(struct device *dev,
+                            struct device_attribute *attr,
+                            const char *buffer, size_t count)
+{
+       bool value;
+       union acpi_object *r;
+       int ret;
+
+       ret = kstrtobool(buffer, &value);
+       if (ret)
+               return ret;
+
+       r = lg_wmab(WM_FN_LOCK, WM_SET, value);
+       if (!r)
+               return -EIO;
+
+       kfree(r);
+       return count;
+}
+
+static ssize_t fn_lock_show(struct device *dev,
+                           struct device_attribute *attr, char *buffer)
+{
+       unsigned int status;
+       union acpi_object *r;
+
+       r = lg_wmab(WM_FN_LOCK, WM_GET, 0);
+       if (!r)
+               return -EIO;
+
+       if (r->type != ACPI_TYPE_BUFFER) {
+               kfree(r);
+               return -EIO;
+       }
+
+       status = !!r->buffer.pointer[0];
+       kfree(r);
+
+       return snprintf(buffer, PAGE_SIZE, "%d\n", status);
+}
+
+static ssize_t battery_care_limit_store(struct device *dev,
+                                       struct device_attribute *attr,
+                                       const char *buffer, size_t count)
+{
+       unsigned long value;
+       int ret;
+
+       ret = kstrtoul(buffer, 10, &value);
+       if (ret)
+               return ret;
+
+       if (value == 100 || value == 80) {
+               union acpi_object *r;
+
+               r = lg_wmab(WM_BATT_LIMIT, WM_SET, value);
+               if (!r)
+                       return -EIO;
+
+               kfree(r);
+               return count;
+       }
+
+       return -EINVAL;
+}
+
+static ssize_t battery_care_limit_show(struct device *dev,
+                                      struct device_attribute *attr,
+                                      char *buffer)
+{
+       unsigned int status;
+       union acpi_object *r;
+
+       r = lg_wmab(WM_BATT_LIMIT, WM_GET, 0);
+       if (!r)
+               return -EIO;
+
+       if (r->type != ACPI_TYPE_INTEGER) {
+               kfree(r);
+               return -EIO;
+       }
+
+       status = r->integer.value;
+       kfree(r);
+       if (status != 80 && status != 100)
+               status = 0;
+
+       return snprintf(buffer, PAGE_SIZE, "%d\n", status);
+}
+
+static DEVICE_ATTR_RW(fan_mode);
+static DEVICE_ATTR_RW(usb_charge);
+static DEVICE_ATTR_RW(reader_mode);
+static DEVICE_ATTR_RW(fn_lock);
+static DEVICE_ATTR_RW(battery_care_limit);
+
+static struct attribute *dev_attributes[] = {
+       &dev_attr_fan_mode.attr,
+       &dev_attr_usb_charge.attr,
+       &dev_attr_reader_mode.attr,
+       &dev_attr_fn_lock.attr,
+       &dev_attr_battery_care_limit.attr,
+       NULL
+};
+
+static const struct attribute_group dev_attribute_group = {
+       .attrs = dev_attributes,
+};
+
+static void tpad_led_set(struct led_classdev *cdev,
+                        enum led_brightness brightness)
+{
+       union acpi_object *r;
+
+       r = lg_wmab(WM_TLED, WM_SET, brightness > LED_OFF);
+       kfree(r);
+}
+
+static enum led_brightness tpad_led_get(struct led_classdev *cdev)
+{
+       return ggov(GOV_TLED) > 0 ? LED_ON : LED_OFF;
+}
+
+static LED_DEVICE(tpad_led, 1);
+
+static void kbd_backlight_set(struct led_classdev *cdev,
+                             enum led_brightness brightness)
+{
+       u32 val;
+       union acpi_object *r;
+
+       val = 0x22;
+       if (brightness <= LED_OFF)
+               val = 0;
+       if (brightness >= LED_FULL)
+               val = 0x24;
+       r = lg_wmab(WM_KEY_LIGHT, WM_SET, val);
+       kfree(r);
+}
+
+static enum led_brightness kbd_backlight_get(struct led_classdev *cdev)
+{
+       union acpi_object *r;
+       int val;
+
+       r = lg_wmab(WM_KEY_LIGHT, WM_GET, 0);
+
+       if (!r)
+               return LED_OFF;
+
+       if (r->type != ACPI_TYPE_BUFFER || r->buffer.pointer[1] != 0x05) {
+               kfree(r);
+               return LED_OFF;
+       }
+
+       switch (r->buffer.pointer[0] & 0x27) {
+       case 0x24:
+               val = LED_FULL;
+               break;
+       case 0x22:
+               val = LED_HALF;
+               break;
+       default:
+               val = LED_OFF;
+       }
+
+       kfree(r);
+
+       return val;
+}
+
+static LED_DEVICE(kbd_backlight, 255);
+
+static void wmi_input_destroy(void)
+{
+       if (inited & INIT_INPUT_WMI_2)
+               wmi_remove_notify_handler(WMI_EVENT_GUID2);
+
+       if (inited & INIT_INPUT_WMI_0)
+               wmi_remove_notify_handler(WMI_EVENT_GUID0);
+
+       if (inited & INIT_SPARSE_KEYMAP)
+               input_unregister_device(wmi_input_dev);
+
+       inited &= ~(INIT_INPUT_WMI_0 | INIT_INPUT_WMI_2 | INIT_SPARSE_KEYMAP);
+}
+
+static struct platform_driver pf_driver = {
+       .driver = {
+                  .name = PLATFORM_NAME,
+       }
+};
+
+static int acpi_add(struct acpi_device *device)
+{
+       int ret;
+
+       if (pf_device)
+               return 0;
+
+       ret = platform_driver_register(&pf_driver);
+       if (ret)
+               return ret;
+
+       pf_device = platform_device_register_simple(PLATFORM_NAME,
+                                                   PLATFORM_DEVID_NONE,
+                                                   NULL, 0);
+       if (IS_ERR(pf_device)) {
+               ret = PTR_ERR(pf_device);
+               pf_device = NULL;
+               pr_err("unable to register platform device\n");
+               goto out_platform_registered;
+       }
+
+       ret = sysfs_create_group(&pf_device->dev.kobj, &dev_attribute_group);
+       if (ret)
+               goto out_platform_device;
+
+       if (!led_classdev_register(&pf_device->dev, &kbd_backlight))
+               inited |= INIT_KBD_LED;
+
+       if (!led_classdev_register(&pf_device->dev, &tpad_led))
+               inited |= INIT_TPAD_LED;
+
+       wmi_input_setup();
+
+       return 0;
+
+out_platform_device:
+       platform_device_unregister(pf_device);
+out_platform_registered:
+       platform_driver_unregister(&pf_driver);
+       return ret;
+}
+
+static int acpi_remove(struct acpi_device *device)
+{
+       sysfs_remove_group(&pf_device->dev.kobj, &dev_attribute_group);
+       if (inited & INIT_KBD_LED)
+               led_classdev_unregister(&kbd_backlight);
+
+       if (inited & INIT_TPAD_LED)
+               led_classdev_unregister(&tpad_led);
+
+       wmi_input_destroy();
+       platform_device_unregister(pf_device);
+       pf_device = NULL;
+       platform_driver_unregister(&pf_driver);
+
+       return 0;
+}
+
+static const struct acpi_device_id device_ids[] = {
+       {"LGEX0815", 0},
+       {"", 0}
+};
+MODULE_DEVICE_TABLE(acpi, device_ids);
+
+static struct acpi_driver acpi_driver = {
+       .name = "LG Gram Laptop Support",
+       .class = "lg-laptop",
+       .ids = device_ids,
+       .ops = {
+               .add = acpi_add,
+               .remove = acpi_remove,
+               .notify = acpi_notify,
+               },
+       .owner = THIS_MODULE,
+};
+
+static int __init acpi_init(void)
+{
+       int result;
+
+       result = acpi_bus_register_driver(&acpi_driver);
+       if (result < 0) {
+               ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error registering driver\n"));
+               return -ENODEV;
+       }
+
+       return 0;
+}
+
+static void __exit acpi_exit(void)
+{
+       acpi_bus_unregister_driver(&acpi_driver);
+}
+
+module_init(acpi_init);
+module_exit(acpi_exit);