// SPDX-License-Identifier: GPL-2.0-only

  /*
   * HID driver for some ITE "special" devices
   * Copyright (c) 2017 Hans de Goede <hdegoede@redhat.com>

   */
  
  #include <linux/device.h>
  #include <linux/input.h>
  #include <linux/hid.h>
  #include <linux/module.h>
  
  #include "hid-ids.h"

  #define QUIRK_TOUCHPAD_ON_OFF_REPORT		BIT(0)
  
  static __u8 *ite_report_fixup(struct hid_device *hdev, __u8 *rdesc, unsigned int *rsize)
  {
  	unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
  
  	if (quirks & QUIRK_TOUCHPAD_ON_OFF_REPORT) {
  		if (*rsize == 188 && rdesc[162] == 0x81 && rdesc[163] == 0x02) {
  			hid_info(hdev, "Fixing up ITE keyboard report descriptor
  ");
  			rdesc[163] = HID_MAIN_ITEM_RELATIVE;
  		}
  	}
  
  	return rdesc;
  }
  
  static int ite_input_mapping(struct hid_device *hdev,
  		struct hid_input *hi, struct hid_field *field,
  		struct hid_usage *usage, unsigned long **bit,
  		int *max)
  {
  
  	unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
  
  	if ((quirks & QUIRK_TOUCHPAD_ON_OFF_REPORT) &&
  	    (usage->hid & HID_USAGE_PAGE) == 0x00880000) {
  		if (usage->hid == 0x00880078) {
  			/* Touchpad on, userspace expects F22 for this */
  			hid_map_usage_clear(hi, usage, bit, max, EV_KEY, KEY_F22);
  			return 1;
  		}
  		if (usage->hid == 0x00880079) {
  			/* Touchpad off, userspace expects F23 for this */
  			hid_map_usage_clear(hi, usage, bit, max, EV_KEY, KEY_F23);
  			return 1;
  		}
  		return -1;
  	}
  
  	return 0;
  }

  static int ite_event(struct hid_device *hdev, struct hid_field *field,
  		     struct hid_usage *usage, __s32 value)
  {
  	struct input_dev *input;
  
  	if (!(hdev->claimed & HID_CLAIMED_INPUT) || !field->hidinput)
  		return 0;
  
  	input = field->hidinput->input;
  
  	/*
  	 * The ITE8595 always reports 0 as value for the rfkill button. Luckily
  	 * it is the only button in its report, and it sends a report on
  	 * release only, so receiving a report means the button was pressed.
  	 */
  	if (usage->hid == HID_GD_RFKILL_BTN) {
  		input_event(input, EV_KEY, KEY_RFKILL, 1);
  		input_sync(input);
  		input_event(input, EV_KEY, KEY_RFKILL, 0);
  		input_sync(input);
  		return 1;
  	}
  
  	return 0;
  }

  static int ite_probe(struct hid_device *hdev, const struct hid_device_id *id)
  {
  	int ret;
  
  	hid_set_drvdata(hdev, (void *)id->driver_data);
  
  	ret = hid_open_report(hdev);
  	if (ret)
  		return ret;
  
  	return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
  }

  static const struct hid_device_id ite_devices[] = {
  	{ HID_USB_DEVICE(USB_VENDOR_ID_ITE, USB_DEVICE_ID_ITE8595) },

  	{ HID_USB_DEVICE(USB_VENDOR_ID_258A, USB_DEVICE_ID_258A_6A88) },

  	/* ITE8595 USB kbd ctlr, with Synaptics touchpad connected to it. */

  	{ HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
  		     USB_VENDOR_ID_SYNAPTICS,

  		     USB_DEVICE_ID_SYNAPTICS_ACER_SWITCH5_012),
  	  .driver_data = QUIRK_TOUCHPAD_ON_OFF_REPORT },

  	/* ITE8910 USB kbd ctlr, with Synaptics touchpad connected to it. */
  	{ HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
  		     USB_VENDOR_ID_SYNAPTICS,
  		     USB_DEVICE_ID_SYNAPTICS_ACER_ONE_S1003) },

  	{ }
  };
  MODULE_DEVICE_TABLE(hid, ite_devices);
  
  static struct hid_driver ite_driver = {
  	.name = "itetech",
  	.id_table = ite_devices,

  	.probe = ite_probe,
  	.report_fixup = ite_report_fixup,
  	.input_mapping = ite_input_mapping,

  	.event = ite_event,
  };
  module_hid_driver(ite_driver);
  
  MODULE_LICENSE("GPL");