// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   *  Force feedback support for GreenAsia (Product ID 0x12) based devices
   *
   *  The devices are distributed under various names and the same USB device ID
   *  can be used in many game controllers.
   *

   *  0e8f:0012 "GreenAsia Inc.    USB Joystick     "
   *   - tested with MANTA Warior MM816 and SpeedLink Strike2 SL-6635.
   *
   *  Copyright (c) 2008 Lukasz Lubojanski <lukasz@lubojanski.info>
   */
  
  /*

   */
  
  #include <linux/input.h>

  #include <linux/slab.h>

  #include <linux/hid.h>

  #include <linux/module.h>

  #include "hid-ids.h"

  
  #ifdef CONFIG_GREENASIA_FF

  
  struct gaff_device {
  	struct hid_report *report;
  };
  
  static int hid_gaff_play(struct input_dev *dev, void *data,
  			 struct ff_effect *effect)
  {
  	struct hid_device *hid = input_get_drvdata(dev);
  	struct gaff_device *gaff = data;
  	int left, right;
  
  	left = effect->u.rumble.strong_magnitude;
  	right = effect->u.rumble.weak_magnitude;
  
  	dbg_hid("called with 0x%04x 0x%04x", left, right);
  
  	left = left * 0xfe / 0xffff;
  	right = right * 0xfe / 0xffff;
  
  	gaff->report->field[0]->value[0] = 0x51;
  	gaff->report->field[0]->value[1] = 0x0;
  	gaff->report->field[0]->value[2] = right;
  	gaff->report->field[0]->value[3] = 0;
  	gaff->report->field[0]->value[4] = left;
  	gaff->report->field[0]->value[5] = 0;
  	dbg_hid("running with 0x%02x 0x%02x", left, right);

  	hid_hw_request(hid, gaff->report, HID_REQ_SET_REPORT);

  
  	gaff->report->field[0]->value[0] = 0xfa;
  	gaff->report->field[0]->value[1] = 0xfe;
  	gaff->report->field[0]->value[2] = 0x0;
  	gaff->report->field[0]->value[4] = 0x0;

  	hid_hw_request(hid, gaff->report, HID_REQ_SET_REPORT);

  
  	return 0;
  }
  
  static int gaff_init(struct hid_device *hid)
  {
  	struct gaff_device *gaff;
  	struct hid_report *report;

  	struct hid_input *hidinput;

  	struct list_head *report_list =
  			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
  	struct list_head *report_ptr = report_list;

  	struct input_dev *dev;

  	int error;

  	if (list_empty(&hid->inputs)) {
  		hid_err(hid, "no inputs found
  ");
  		return -ENODEV;
  	}
  	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
  	dev = hidinput->input;

  	if (list_empty(report_list)) {

  		hid_err(hid, "no output reports found
  ");

  		return -ENODEV;
  	}
  
  	report_ptr = report_ptr->next;
  
  	report = list_entry(report_ptr, struct hid_report, list);
  	if (report->maxfield < 1) {

  		hid_err(hid, "no fields in the report
  ");

  		return -ENODEV;
  	}
  
  	if (report->field[0]->report_count < 6) {

  		hid_err(hid, "not enough values in the field
  ");

  		return -ENODEV;
  	}
  
  	gaff = kzalloc(sizeof(struct gaff_device), GFP_KERNEL);
  	if (!gaff)
  		return -ENOMEM;
  
  	set_bit(FF_RUMBLE, dev->ffbit);
  
  	error = input_ff_create_memless(dev, gaff, hid_gaff_play);
  	if (error) {
  		kfree(gaff);
  		return error;
  	}
  
  	gaff->report = report;
  	gaff->report->field[0]->value[0] = 0x51;
  	gaff->report->field[0]->value[1] = 0x00;
  	gaff->report->field[0]->value[2] = 0x00;
  	gaff->report->field[0]->value[3] = 0x00;

  	hid_hw_request(hid, gaff->report, HID_REQ_SET_REPORT);

  
  	gaff->report->field[0]->value[0] = 0xfa;
  	gaff->report->field[0]->value[1] = 0xfe;

  	hid_hw_request(hid, gaff->report, HID_REQ_SET_REPORT);

  	hid_info(hid, "Force Feedback for GreenAsia 0x12 devices by Lukasz Lubojanski <lukasz@lubojanski.info>
  ");

  
  	return 0;
  }

  #else
  static inline int gaff_init(struct hid_device *hdev)
  {
  	return 0;
  }
  #endif

  
  static int ga_probe(struct hid_device *hdev, const struct hid_device_id *id)
  {
  	int ret;
  
  	dev_dbg(&hdev->dev, "Greenasia HID hardware probe...");
  
  	ret = hid_parse(hdev);
  	if (ret) {

  		hid_err(hdev, "parse failed
  ");

  		goto err;
  	}
  
  	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
  	if (ret) {

  		hid_err(hdev, "hw start failed
  ");

  		goto err;
  	}
  
  	gaff_init(hdev);
  
  	return 0;
  err:
  	return ret;
  }
  
  static const struct hid_device_id ga_devices[] = {
  	{ HID_USB_DEVICE(USB_VENDOR_ID_GREENASIA, 0x0012),  },
  	{ }
  };
  MODULE_DEVICE_TABLE(hid, ga_devices);
  
  static struct hid_driver ga_driver = {
  	.name = "greenasia",
  	.id_table = ga_devices,
  	.probe = ga_probe,
  };

  module_hid_driver(ga_driver);

  MODULE_LICENSE("GPL");