/*
   * Force feedback support for ACRUX game controllers
   *
   * From what I have gathered, these devices are mass produced in China
   * by several vendors. They often share the same design as the original
   * Xbox 360 controller.
   *
   * 1a34:0802 "ACRUX USB GAMEPAD 8116"
   *  - tested with an EXEQ EQ-PCU-02090 game controller.
   *
   * Copyright (c) 2010 Sergei Kolzun <x0r@dv-life.ru>
   */
  
  /*
   * 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.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */
  
  #include <linux/input.h>
  #include <linux/slab.h>
  #include <linux/hid.h>
  #include <linux/module.h>
  
  #include "hid-ids.h"
  
  #ifdef CONFIG_HID_ACRUX_FF
  
  struct axff_device {
  	struct hid_report *report;
  };
  
  static int axff_play(struct input_dev *dev, void *data, struct ff_effect *effect)
  {
  	struct hid_device *hid = input_get_drvdata(dev);
  	struct axff_device *axff = data;
  	struct hid_report *report = axff->report;
  	int field_count = 0;
  	int left, right;
  	int i, j;
  
  	left = effect->u.rumble.strong_magnitude;
  	right = effect->u.rumble.weak_magnitude;
  
  	dbg_hid("called with 0x%04x 0x%04x", left, right);
  
  	left = left * 0xff / 0xffff;
  	right = right * 0xff / 0xffff;
  
  	for (i = 0; i < report->maxfield; i++) {
  		for (j = 0; j < report->field[i]->report_count; j++) {
  			report->field[i]->value[j] =
  				field_count % 2 ? right : left;
  			field_count++;
  		}
  	}
  
  	dbg_hid("running with 0x%02x 0x%02x", left, right);
  	hid_hw_request(hid, axff->report, HID_REQ_SET_REPORT);
  
  	return 0;
  }
  
  static int axff_init(struct hid_device *hid)
  {
  	struct axff_device *axff;
  	struct hid_report *report;
  	struct hid_input *hidinput = list_first_entry(&hid->inputs, struct hid_input, list);
  	struct list_head *report_list =&hid->report_enum[HID_OUTPUT_REPORT].report_list;
  	struct input_dev *dev = hidinput->input;
  	int field_count = 0;
  	int i, j;
  	int error;
  
  	if (list_empty(report_list)) {
  		hid_err(hid, "no output reports found
  ");
  		return -ENODEV;
  	}
  
  	report = list_first_entry(report_list, struct hid_report, list);
  	for (i = 0; i < report->maxfield; i++) {
  		for (j = 0; j < report->field[i]->report_count; j++) {
  			report->field[i]->value[j] = 0x00;
  			field_count++;
  		}
  	}
  
  	if (field_count < 4 && hid->product != 0xf705) {
  		hid_err(hid, "not enough fields in the report: %d
  ",
  			field_count);
  		return -ENODEV;
  	}
  
  	axff = kzalloc(sizeof(struct axff_device), GFP_KERNEL);
  	if (!axff)
  		return -ENOMEM;
  
  	set_bit(FF_RUMBLE, dev->ffbit);
  
  	error = input_ff_create_memless(dev, axff, axff_play);
  	if (error)
  		goto err_free_mem;
  
  	axff->report = report;
  	hid_hw_request(hid, axff->report, HID_REQ_SET_REPORT);
  
  	hid_info(hid, "Force Feedback for ACRUX game controllers by Sergei Kolzun <x0r@dv-life.ru>
  ");
  
  	return 0;
  
  err_free_mem:
  	kfree(axff);
  	return error;
  }
  #else
  static inline int axff_init(struct hid_device *hid)
  {
  	return 0;
  }
  #endif
  
  static int ax_probe(struct hid_device *hdev, const struct hid_device_id *id)
  {
  	int error;
  
  	dev_dbg(&hdev->dev, "ACRUX HID hardware probe...
  ");
  
  	error = hid_parse(hdev);
  	if (error) {
  		hid_err(hdev, "parse failed
  ");
  		return error;
  	}
  
  	error = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
  	if (error) {
  		hid_err(hdev, "hw start failed
  ");
  		return error;
  	}
  
  	error = axff_init(hdev);
  	if (error) {
  		/*
  		 * Do not fail device initialization completely as device
  		 * may still be partially operable, just warn.
  		 */
  		hid_warn(hdev,
  			 "Failed to enable force feedback support, error: %d
  ",
  			 error);
  	}
  
  	/*
  	 * We need to start polling device right away, otherwise
  	 * it will go into a coma.
  	 */
  	error = hid_hw_open(hdev);
  	if (error) {
  		dev_err(&hdev->dev, "hw open failed
  ");
  		hid_hw_stop(hdev);
  		return error;
  	}
  
  	return 0;
  }
  
  static void ax_remove(struct hid_device *hdev)
  {
  	hid_hw_close(hdev);
  	hid_hw_stop(hdev);
  }
  
  static const struct hid_device_id ax_devices[] = {
  	{ HID_USB_DEVICE(USB_VENDOR_ID_ACRUX, 0x0802), },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_ACRUX, 0xf705), },
  	{ }
  };
  MODULE_DEVICE_TABLE(hid, ax_devices);
  
  static struct hid_driver ax_driver = {
  	.name		= "acrux",
  	.id_table	= ax_devices,
  	.probe		= ax_probe,
  	.remove		= ax_remove,
  };
  module_hid_driver(ax_driver);
  
  MODULE_AUTHOR("Sergei Kolzun");
  MODULE_DESCRIPTION("Force feedback support for ACRUX game controllers");
  MODULE_LICENSE("GPL");