// SPDX-License-Identifier: GPL-2.0+
  /*
   *  HID driver for UC-Logic devices not fully compliant with HID standard
   *
   *  Copyright (c) 2010-2014 Nikolai Kondrashov
   *  Copyright (c) 2013 Martin Rusko
   */
  
  /*
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License as published by the Free
   * Software Foundation; either version 2 of the License, or (at your option)
   * any later version.
   */
  
  #include <linux/device.h>
  #include <linux/hid.h>
  #include <linux/module.h>

  #include <linux/timer.h>

  #include "usbhid/usbhid.h"

  #include "hid-uclogic-params.h"

  
  #include "hid-ids.h"

  /* Driver data */
  struct uclogic_drvdata {

  	/* Interface parameters */
  	struct uclogic_params params;
  	/* Pointer to the replacement report descriptor. NULL if none. */
  	__u8 *desc_ptr;
  	/*
  	 * Size of the replacement report descriptor.
  	 * Only valid if desc_ptr is not NULL
  	 */
  	unsigned int desc_size;

  	/* Pen input device */
  	struct input_dev *pen_input;
  	/* In-range timer */
  	struct timer_list inrange_timer;

  	/* Last rotary encoder state, or U8_MAX for none */
  	u8 re_state;

  };

  /**
   * uclogic_inrange_timeout - handle pen in-range state timeout.
   * Emulate input events normally generated when pen goes out of range for
   * tablets which don't report that.
   *
   * @t:	The timer the timeout handler is attached to, stored in a struct
   *	uclogic_drvdata.
   */
  static void uclogic_inrange_timeout(struct timer_list *t)
  {
  	struct uclogic_drvdata *drvdata = from_timer(drvdata, t,
  							inrange_timer);
  	struct input_dev *input = drvdata->pen_input;
  
  	if (input == NULL)
  		return;
  	input_report_abs(input, ABS_PRESSURE, 0);
  	/* If BTN_TOUCH state is changing */
  	if (test_bit(BTN_TOUCH, input->key)) {
  		input_event(input, EV_MSC, MSC_SCAN,
  				/* Digitizer Tip Switch usage */
  				0xd0042);
  		input_report_key(input, BTN_TOUCH, 0);
  	}
  	input_report_key(input, BTN_TOOL_PEN, 0);
  	input_sync(input);
  }

  static __u8 *uclogic_report_fixup(struct hid_device *hdev, __u8 *rdesc,
  					unsigned int *rsize)
  {

  	struct uclogic_drvdata *drvdata = hid_get_drvdata(hdev);

  	if (drvdata->desc_ptr != NULL) {
  		rdesc = drvdata->desc_ptr;
  		*rsize = drvdata->desc_size;

  	}

  	return rdesc;
  }

  static int uclogic_input_mapping(struct hid_device *hdev,
  				 struct hid_input *hi,
  				 struct hid_field *field,
  				 struct hid_usage *usage,
  				 unsigned long **bit,
  				 int *max)

  {
  	struct uclogic_drvdata *drvdata = hid_get_drvdata(hdev);

  	struct uclogic_params *params = &drvdata->params;

  
  	/* discard the unused pen interface */

  	if (params->pen_unused && (field->application == HID_DG_PEN))

  		return -1;
  
  	/* let hid-core decide what to do */
  	return 0;
  }
  
  static int uclogic_input_configured(struct hid_device *hdev,
  		struct hid_input *hi)
  {

  	struct uclogic_drvdata *drvdata = hid_get_drvdata(hdev);
  	struct uclogic_params *params = &drvdata->params;

  	char *name;
  	const char *suffix = NULL;
  	struct hid_field *field;
  	size_t len;
  
  	/* no report associated (HID_QUIRK_MULTI_INPUT not set) */
  	if (!hi->report)
  		return 0;

  	/*
  	 * If this is the input corresponding to the pen report
  	 * in need of tweaking.
  	 */
  	if (hi->report->id == params->pen.id) {
  		/* Remember the input device so we can simulate events */
  		drvdata->pen_input = hi->input;
  	}

  	field = hi->report->field[0];
  
  	switch (field->application) {
  	case HID_GD_KEYBOARD:
  		suffix = "Keyboard";
  		break;
  	case HID_GD_MOUSE:
  		suffix = "Mouse";
  		break;
  	case HID_GD_KEYPAD:
  		suffix = "Pad";
  		break;
  	case HID_DG_PEN:
  		suffix = "Pen";
  		break;
  	case HID_CP_CONSUMER_CONTROL:
  		suffix = "Consumer Control";
  		break;
  	case HID_GD_SYSTEM_CONTROL:
  		suffix = "System Control";
  		break;
  	}
  
  	if (suffix) {
  		len = strlen(hdev->name) + 2 + strlen(suffix);
  		name = devm_kzalloc(&hi->input->dev, len, GFP_KERNEL);
  		if (name) {
  			snprintf(name, len, "%s %s", hdev->name, suffix);
  			hi->input->name = name;
  		}
  	}
  
  	return 0;
  }

  static int uclogic_probe(struct hid_device *hdev,
  		const struct hid_device_id *id)
  {
  	int rc;

  	struct uclogic_drvdata *drvdata = NULL;
  	bool params_initialized = false;

  
  	/*
  	 * libinput requires the pad interface to be on a different node
  	 * than the pen, so use QUIRK_MULTI_INPUT for all tablets.
  	 */
  	hdev->quirks |= HID_QUIRK_MULTI_INPUT;
  
  	/* Allocate and assign driver data */
  	drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);

  	if (drvdata == NULL) {
  		rc = -ENOMEM;
  		goto failure;
  	}

  	timer_setup(&drvdata->inrange_timer, uclogic_inrange_timeout, 0);

  	drvdata->re_state = U8_MAX;

  	hid_set_drvdata(hdev, drvdata);

  	/* Initialize the device and retrieve interface parameters */
  	rc = uclogic_params_init(&drvdata->params, hdev);
  	if (rc != 0) {
  		hid_err(hdev, "failed probing parameters: %d
  ", rc);
  		goto failure;
  	}
  	params_initialized = true;
  	hid_dbg(hdev, "parameters:
  " UCLOGIC_PARAMS_FMT_STR,
  		UCLOGIC_PARAMS_FMT_ARGS(&drvdata->params));
  	if (drvdata->params.invalid) {
  		hid_info(hdev, "interface is invalid, ignoring
  ");
  		rc = -ENODEV;
  		goto failure;
  	}

  	/* Generate replacement report descriptor */
  	rc = uclogic_params_get_desc(&drvdata->params,
  				     &drvdata->desc_ptr,
  				     &drvdata->desc_size);
  	if (rc) {
  		hid_err(hdev,
  			"failed generating replacement report descriptor: %d
  ",
  			rc);
  		goto failure;

  	}
  
  	rc = hid_parse(hdev);
  	if (rc) {
  		hid_err(hdev, "parse failed
  ");

  		goto failure;

  	}
  
  	rc = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
  	if (rc) {
  		hid_err(hdev, "hw start failed
  ");

  		goto failure;

  	}
  
  	return 0;

  failure:
  	/* Assume "remove" might not be called if "probe" failed */
  	if (params_initialized)
  		uclogic_params_cleanup(&drvdata->params);
  	return rc;

  }

  #ifdef CONFIG_PM
  static int uclogic_resume(struct hid_device *hdev)
  {
  	int rc;
  	struct uclogic_params params;
  
  	/* Re-initialize the device, but discard parameters */
  	rc = uclogic_params_init(&params, hdev);
  	if (rc != 0)
  		hid_err(hdev, "failed to re-initialize the device
  ");
  	else
  		uclogic_params_cleanup(&params);
  
  	return rc;
  }
  #endif

  static int uclogic_raw_event(struct hid_device *hdev,
  				struct hid_report *report,
  				u8 *data, int size)

  {
  	struct uclogic_drvdata *drvdata = hid_get_drvdata(hdev);

  	struct uclogic_params *params = &drvdata->params;

  	/* Tweak pen reports, if necessary */
  	if (!params->pen_unused &&
  	    (report->type == HID_INPUT_REPORT) &&
  	    (report->id == params->pen.id) &&

  	    (size >= 2)) {

  		/* If it's the "virtual" frame controls report */
  		if (params->frame.id != 0 &&
  		    data[1] & params->pen_frame_flag) {
  			/* Change to virtual frame controls report ID */
  			data[0] = params->frame.id;
  			return 0;
  		}
  		/* If in-range reports are inverted */
  		if (params->pen.inrange ==
  			UCLOGIC_PARAMS_PEN_INRANGE_INVERTED) {

  			/* Invert the in-range bit */
  			data[1] ^= 0x40;

  		}

  		/*
  		 * If report contains fragmented high-resolution pen
  		 * coordinates
  		 */
  		if (size >= 10 && params->pen.fragmented_hires) {
  			u8 pressure_low_byte;
  			u8 pressure_high_byte;
  
  			/* Lift pressure bytes */
  			pressure_low_byte = data[6];
  			pressure_high_byte = data[7];
  			/*
  			 * Move Y coord to make space for high-order X
  			 * coord byte
  			 */
  			data[6] = data[5];
  			data[5] = data[4];
  			/* Move high-order X coord byte */
  			data[4] = data[8];
  			/* Move high-order Y coord byte */
  			data[7] = data[9];
  			/* Place pressure bytes */
  			data[8] = pressure_low_byte;
  			data[9] = pressure_high_byte;
  		}

  		/* If we need to emulate in-range detection */
  		if (params->pen.inrange == UCLOGIC_PARAMS_PEN_INRANGE_NONE) {
  			/* Set in-range bit */
  			data[1] |= 0x40;
  			/* (Re-)start in-range timeout */
  			mod_timer(&drvdata->inrange_timer,
  					jiffies + msecs_to_jiffies(100));
  		}

  	}

  	/* Tweak frame control reports, if necessary */
  	if ((report->type == HID_INPUT_REPORT) &&
  	    (report->id == params->frame.id)) {
  		/* If need to, and can, set pad device ID for Wacom drivers */
  		if (params->frame.dev_id_byte > 0 &&
  		    params->frame.dev_id_byte < size) {
  			data[params->frame.dev_id_byte] = 0xf;
  		}

  		/* If need to, and can, read rotary encoder state change */
  		if (params->frame.re_lsb > 0 &&
  		    params->frame.re_lsb / 8 < size) {
  			unsigned int byte = params->frame.re_lsb / 8;
  			unsigned int bit = params->frame.re_lsb % 8;
  
  			u8 change;
  			u8 prev_state = drvdata->re_state;
  			/* Read Gray-coded state */
  			u8 state = (data[byte] >> bit) & 0x3;
  			/* Encode state change into 2-bit signed integer */
  			if ((prev_state == 1 && state == 0) ||
  			    (prev_state == 2 && state == 3)) {
  				change = 1;
  			} else if ((prev_state == 2 && state == 0) ||
  				   (prev_state == 1 && state == 3)) {
  				change = 3;
  			} else {
  				change = 0;
  			}
  			/* Write change */
  			data[byte] = (data[byte] & ~((u8)3 << bit)) |
  					(change << bit);
  			/* Remember state */
  			drvdata->re_state = state;
  		}

  	}

  	return 0;
  }

  static void uclogic_remove(struct hid_device *hdev)
  {
  	struct uclogic_drvdata *drvdata = hid_get_drvdata(hdev);

  	del_timer_sync(&drvdata->inrange_timer);

  	hid_hw_stop(hdev);
  	kfree(drvdata->desc_ptr);
  	uclogic_params_cleanup(&drvdata->params);
  }

  static const struct hid_device_id uclogic_devices[] = {
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
  				USB_DEVICE_ID_UCLOGIC_TABLET_PF1209) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
  				USB_DEVICE_ID_UCLOGIC_TABLET_WP4030U) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
  				USB_DEVICE_ID_UCLOGIC_TABLET_WP5540U) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
  				USB_DEVICE_ID_UCLOGIC_TABLET_WP8060U) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
  				USB_DEVICE_ID_UCLOGIC_TABLET_WP1062) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
  				USB_DEVICE_ID_UCLOGIC_WIRELESS_TABLET_TWHL850) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
  				USB_DEVICE_ID_UCLOGIC_TABLET_TWHA60) },

  	{ HID_USB_DEVICE(USB_VENDOR_ID_HUION,
  				USB_DEVICE_ID_HUION_TABLET) },

  	{ HID_USB_DEVICE(USB_VENDOR_ID_HUION,
  				USB_DEVICE_ID_HUION_HS64) },

  	{ HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
  				USB_DEVICE_ID_HUION_TABLET) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
  				USB_DEVICE_ID_YIYNOVA_TABLET) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
  				USB_DEVICE_ID_UCLOGIC_UGEE_TABLET_81) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
  				USB_DEVICE_ID_UCLOGIC_UGEE_TABLET_45) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,

  				USB_DEVICE_ID_UCLOGIC_UGEE_TABLET_47) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,

  				USB_DEVICE_ID_UCLOGIC_DRAWIMAGE_G3) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UGTIZER,
  				USB_DEVICE_ID_UGTIZER_TABLET_GP0610) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UGEE,

  				USB_DEVICE_ID_UGEE_TABLET_G5) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UGEE,

  				USB_DEVICE_ID_UGEE_TABLET_EX07S) },

  	{ HID_USB_DEVICE(USB_VENDOR_ID_UGEE,

  				USB_DEVICE_ID_UGEE_TABLET_RAINBOW_CV720) },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_UGEE,

  				USB_DEVICE_ID_UGEE_XPPEN_TABLET_G540) },

  	{ HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
  				USB_DEVICE_ID_UGEE_XPPEN_TABLET_G640) },

  	{ HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
  				USB_DEVICE_ID_UGEE_XPPEN_TABLET_DECO01) },

  	{ }
  };
  MODULE_DEVICE_TABLE(hid, uclogic_devices);
  
  static struct hid_driver uclogic_driver = {
  	.name = "uclogic",
  	.id_table = uclogic_devices,
  	.probe = uclogic_probe,

  	.remove = uclogic_remove,

  	.report_fixup = uclogic_report_fixup,
  	.raw_event = uclogic_raw_event,
  	.input_mapping = uclogic_input_mapping,
  	.input_configured = uclogic_input_configured,

  #ifdef CONFIG_PM
  	.resume	          = uclogic_resume,
  	.reset_resume     = uclogic_resume,
  #endif

  };
  module_hid_driver(uclogic_driver);
  
  MODULE_AUTHOR("Martin Rusko");
  MODULE_AUTHOR("Nikolai Kondrashov");
  MODULE_LICENSE("GPL");