/*
   * Force feedback support for DragonRise Inc. game controllers
   *
   * From what I have gathered, these devices are mass produced in China and are
   * distributed under several vendors. They often share the same design as
   * the original PlayStation DualShock controller.
   *
   * 0079:0006 "DragonRise Inc.   Generic   USB  Joystick  "
   *  - tested with a Tesun USB-703 game controller.
   *
   * Copyright (c) 2009 Richard Walmsley <richwalm@gmail.com>
   */
  
  /*
   * 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/usb.h>
  #include <linux/hid.h>

  #include <linux/module.h>

  
  #include "hid-ids.h"

  
  #ifdef CONFIG_DRAGONRISE_FF

  #include "usbhid/usbhid.h"
  
  struct drff_device {
  	struct hid_report *report;
  };
  
  static int drff_play(struct input_dev *dev, void *data,
  				 struct ff_effect *effect)
  {
  	struct hid_device *hid = input_get_drvdata(dev);
  	struct drff_device *drff = data;
  	int strong, weak;
  
  	strong = effect->u.rumble.strong_magnitude;
  	weak = effect->u.rumble.weak_magnitude;
  
  	dbg_hid("called with 0x%04x 0x%04x", strong, weak);
  
  	if (strong || weak) {
  		strong = strong * 0xff / 0xffff;
  		weak = weak * 0xff / 0xffff;
  
  		/* While reverse engineering this device, I found that when
  		   this value is set, it causes the strong rumble to function
  		   at a near maximum speed, so we'll bypass it. */
  		if (weak == 0x0a)
  			weak = 0x0b;
  
  		drff->report->field[0]->value[0] = 0x51;
  		drff->report->field[0]->value[1] = 0x00;
  		drff->report->field[0]->value[2] = weak;
  		drff->report->field[0]->value[4] = strong;
  		usbhid_submit_report(hid, drff->report, USB_DIR_OUT);
  
  		drff->report->field[0]->value[0] = 0xfa;
  		drff->report->field[0]->value[1] = 0xfe;
  	} else {
  		drff->report->field[0]->value[0] = 0xf3;
  		drff->report->field[0]->value[1] = 0x00;
  	}
  
  	drff->report->field[0]->value[2] = 0x00;
  	drff->report->field[0]->value[4] = 0x00;
  	dbg_hid("running with 0x%02x 0x%02x", strong, weak);
  	usbhid_submit_report(hid, drff->report, USB_DIR_OUT);
  
  	return 0;
  }
  
  static int drff_init(struct hid_device *hid)
  {
  	struct drff_device *drff;
  	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 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);
  	if (report->maxfield < 1) {

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

  		return -ENODEV;
  	}
  
  	if (report->field[0]->report_count < 7) {

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

  		return -ENODEV;
  	}
  
  	drff = kzalloc(sizeof(struct drff_device), GFP_KERNEL);
  	if (!drff)
  		return -ENOMEM;
  
  	set_bit(FF_RUMBLE, dev->ffbit);
  
  	error = input_ff_create_memless(dev, drff, drff_play);
  	if (error) {
  		kfree(drff);
  		return error;
  	}
  
  	drff->report = report;
  	drff->report->field[0]->value[0] = 0xf3;
  	drff->report->field[0]->value[1] = 0x00;
  	drff->report->field[0]->value[2] = 0x00;
  	drff->report->field[0]->value[3] = 0x00;
  	drff->report->field[0]->value[4] = 0x00;
  	drff->report->field[0]->value[5] = 0x00;
  	drff->report->field[0]->value[6] = 0x00;
  	usbhid_submit_report(hid, drff->report, USB_DIR_OUT);

  	hid_info(hid, "Force Feedback for DragonRise Inc. "
  		 "game controllers by Richard Walmsley <richwalm@gmail.com>
  ");

  
  	return 0;
  }

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

  /*
   * The original descriptor of joystick with PID 0x0011, represented by DVTech PC
   * JS19. It seems both copied from another device and a result of confusion
   * either about the specification or about the program used to create the
   * descriptor. In any case, it's a wonder it works on Windows.
   *
   *  Usage Page (Desktop),             ; Generic desktop controls (01h)
   *  Usage (Joystik),                  ; Joystik (04h, application collection)
   *  Collection (Application),
   *    Collection (Logical),
   *      Report Size (8),
   *      Report Count (5),
   *      Logical Minimum (0),
   *      Logical Maximum (255),
   *      Physical Minimum (0),
   *      Physical Maximum (255),
   *      Usage (X),                    ; X (30h, dynamic value)
   *      Usage (X),                    ; X (30h, dynamic value)
   *      Usage (X),                    ; X (30h, dynamic value)
   *      Usage (X),                    ; X (30h, dynamic value)
   *      Usage (Y),                    ; Y (31h, dynamic value)
   *      Input (Variable),
   *      Report Size (4),
   *      Report Count (1),
   *      Logical Maximum (7),
   *      Physical Maximum (315),
   *      Unit (Degrees),
   *      Usage (00h),
   *      Input (Variable, Null State),
   *      Unit,
   *      Report Size (1),
   *      Report Count (10),
   *      Logical Maximum (1),
   *      Physical Maximum (1),
   *      Usage Page (Button),          ; Button (09h)
   *      Usage Minimum (01h),
   *      Usage Maximum (0Ah),
   *      Input (Variable),
   *      Usage Page (FF00h),           ; FF00h, vendor-defined
   *      Report Size (1),
   *      Report Count (10),
   *      Logical Maximum (1),
   *      Physical Maximum (1),
   *      Usage (01h),
   *      Input (Variable),
   *    End Collection,
   *    Collection (Logical),
   *      Report Size (8),
   *      Report Count (4),
   *      Physical Maximum (255),
   *      Logical Maximum (255),
   *      Usage (02h),
   *      Output (Variable),
   *    End Collection,
   *  End Collection
   */
  
  /* Size of the original descriptor of the PID 0x0011 joystick */
  #define PID0011_RDESC_ORIG_SIZE	101
  
  /* Fixed report descriptor for PID 0x011 joystick */
  static __u8 pid0011_rdesc_fixed[] = {
  	0x05, 0x01,         /*  Usage Page (Desktop),           */
  	0x09, 0x04,         /*  Usage (Joystik),                */
  	0xA1, 0x01,         /*  Collection (Application),       */
  	0xA1, 0x02,         /*      Collection (Logical),       */
  	0x14,               /*          Logical Minimum (0),    */
  	0x75, 0x08,         /*          Report Size (8),        */
  	0x95, 0x03,         /*          Report Count (3),       */
  	0x81, 0x01,         /*          Input (Constant),       */
  	0x26, 0xFF, 0x00,   /*          Logical Maximum (255),  */
  	0x95, 0x02,         /*          Report Count (2),       */
  	0x09, 0x30,         /*          Usage (X),              */
  	0x09, 0x31,         /*          Usage (Y),              */
  	0x81, 0x02,         /*          Input (Variable),       */
  	0x75, 0x01,         /*          Report Size (1),        */
  	0x95, 0x04,         /*          Report Count (4),       */
  	0x81, 0x01,         /*          Input (Constant),       */
  	0x25, 0x01,         /*          Logical Maximum (1),    */
  	0x95, 0x0A,         /*          Report Count (10),      */
  	0x05, 0x09,         /*          Usage Page (Button),    */
  	0x19, 0x01,         /*          Usage Minimum (01h),    */
  	0x29, 0x0A,         /*          Usage Maximum (0Ah),    */
  	0x81, 0x02,         /*          Input (Variable),       */
  	0x95, 0x0A,         /*          Report Count (10),      */
  	0x81, 0x01,         /*          Input (Constant),       */
  	0xC0,               /*      End Collection,             */
  	0xC0                /*  End Collection                  */
  };
  
  static __u8 *dr_report_fixup(struct hid_device *hdev, __u8 *rdesc,
  				unsigned int *rsize)
  {
  	switch (hdev->product) {
  	case 0x0011:
  		if (*rsize == PID0011_RDESC_ORIG_SIZE) {
  			rdesc = pid0011_rdesc_fixed;
  			*rsize = sizeof(pid0011_rdesc_fixed);
  		}
  		break;
  	}
  	return rdesc;
  }

  static int dr_probe(struct hid_device *hdev, const struct hid_device_id *id)
  {
  	int ret;
  
  	dev_dbg(&hdev->dev, "DragonRise Inc. 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;
  	}

  	switch (hdev->product) {
  	case 0x0006:
  		ret = drff_init(hdev);
  		if (ret) {
  			dev_err(&hdev->dev, "force feedback init failed
  ");
  			hid_hw_stop(hdev);
  			goto err;
  		}
  		break;
  	}

  
  	return 0;
  err:
  	return ret;
  }
  
  static const struct hid_device_id dr_devices[] = {
  	{ HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, 0x0006),  },

  	{ HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, 0x0011),  },

  	{ }
  };
  MODULE_DEVICE_TABLE(hid, dr_devices);
  
  static struct hid_driver dr_driver = {
  	.name = "dragonrise",
  	.id_table = dr_devices,

  	.report_fixup = dr_report_fixup,

  	.probe = dr_probe,
  };
  
  static int __init dr_init(void)
  {
  	return hid_register_driver(&dr_driver);
  }
  
  static void __exit dr_exit(void)
  {
  	hid_unregister_driver(&dr_driver);
  }
  
  module_init(dr_init);
  module_exit(dr_exit);
  MODULE_LICENSE("GPL");