/*
   *  HID driver for Saitek devices.
   *
   *  PS1000 (USB gamepad):
   *  Fixes the HID report descriptor by removing a non-existent axis and
   *  clearing the constant bit on the input reports for buttons and d-pad.
   *  (This module is based on "hid-ortek".)
   *  Copyright (c) 2012 Andreas Hübner
   *
   *  R.A.T.7, R.A.T.9, M.M.O.7 (USB gaming mice):
   *  Fixes the mode button which cycles through three constantly pressed
   *  buttons. All three press events are mapped to one button and the
   *  missing release event is generated immediately.
   *
   */
  
  /*
   * 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/kernel.h>
  
  #include "hid-ids.h"
  
  #define SAITEK_FIX_PS1000	0x0001
  #define SAITEK_RELEASE_MODE_RAT7	0x0002
  #define SAITEK_RELEASE_MODE_MMO7	0x0004
  
  struct saitek_sc {
  	unsigned long quirks;
  	int mode;
  };
  
  static int saitek_probe(struct hid_device *hdev,
  		const struct hid_device_id *id)
  {
  	unsigned long quirks = id->driver_data;
  	struct saitek_sc *ssc;
  	int ret;
  
  	ssc = devm_kzalloc(&hdev->dev, sizeof(*ssc), GFP_KERNEL);
  	if (ssc == NULL) {
  		hid_err(hdev, "can't alloc saitek descriptor
  ");
  		return -ENOMEM;
  	}
  
  	ssc->quirks = quirks;
  	ssc->mode = -1;
  
  	hid_set_drvdata(hdev, ssc);
  
  	ret = hid_parse(hdev);
  	if (ret) {
  		hid_err(hdev, "parse failed
  ");
  		return ret;
  	}
  
  	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
  	if (ret) {
  		hid_err(hdev, "hw start failed
  ");
  		return ret;
  	}
  
  	return 0;
  }
  
  static __u8 *saitek_report_fixup(struct hid_device *hdev, __u8 *rdesc,
  		unsigned int *rsize)
  {
  	struct saitek_sc *ssc = hid_get_drvdata(hdev);
  
  	if ((ssc->quirks & SAITEK_FIX_PS1000) && *rsize == 137 &&
  			rdesc[20] == 0x09 && rdesc[21] == 0x33 &&
  			rdesc[94] == 0x81 && rdesc[95] == 0x03 &&
  			rdesc[110] == 0x81 && rdesc[111] == 0x03) {
  
  		hid_info(hdev, "Fixing up Saitek PS1000 report descriptor
  ");
  
  		/* convert spurious axis to a "noop" Logical Minimum (0) */
  		rdesc[20] = 0x15;
  		rdesc[21] = 0x00;
  
  		/* clear constant bit on buttons and d-pad */
  		rdesc[95] = 0x02;
  		rdesc[111] = 0x02;
  
  	}
  	return rdesc;
  }
  
  static int saitek_raw_event(struct hid_device *hdev,
  		struct hid_report *report, u8 *raw_data, int size)
  {
  	struct saitek_sc *ssc = hid_get_drvdata(hdev);
  
  	if (ssc->quirks & SAITEK_RELEASE_MODE_RAT7 && size == 7) {
  		/* R.A.T.7 uses bits 13, 14, 15 for the mode */
  		int mode = -1;
  		if (raw_data[1] & 0x01)
  			mode = 0;
  		else if (raw_data[1] & 0x02)
  			mode = 1;
  		else if (raw_data[1] & 0x04)
  			mode = 2;
  
  		/* clear mode bits */
  		raw_data[1] &= ~0x07;
  
  		if (mode != ssc->mode) {
  			hid_dbg(hdev, "entered mode %d
  ", mode);
  			if (ssc->mode != -1) {
  				/* use bit 13 as the mode button */
  				raw_data[1] |= 0x04;
  			}
  			ssc->mode = mode;
  		}
  	} else if (ssc->quirks & SAITEK_RELEASE_MODE_MMO7 && size == 8) {
  
  		/* M.M.O.7 uses bits 8, 22, 23 for the mode */
  		int mode = -1;
  		if (raw_data[1] & 0x80)
  			mode = 0;
  		else if (raw_data[2] & 0x01)
  			mode = 1;
  		else if (raw_data[2] & 0x02)
  			mode = 2;
  
  		/* clear mode bits */
  		raw_data[1] &= ~0x80;
  		raw_data[2] &= ~0x03;
  
  		if (mode != ssc->mode) {
  			hid_dbg(hdev, "entered mode %d
  ", mode);
  			if (ssc->mode != -1) {
  				/* use bit 8 as the mode button, bits 22
  				 * and 23 do not represent buttons
  				 * according to the HID report descriptor
  				 */
  				raw_data[1] |= 0x80;
  			}
  			ssc->mode = mode;
  		}
  	}
  
  	return 0;
  }
  
  static int saitek_event(struct hid_device *hdev, struct hid_field *field,
  		struct hid_usage *usage, __s32 value)
  {
  	struct saitek_sc *ssc = hid_get_drvdata(hdev);
  	struct input_dev *input = field->hidinput->input;
  
  	if (usage->type == EV_KEY && value &&
  			(((ssc->quirks & SAITEK_RELEASE_MODE_RAT7) &&
  			  usage->code - BTN_MOUSE == 10) ||
  			((ssc->quirks & SAITEK_RELEASE_MODE_MMO7) &&
  			 usage->code - BTN_MOUSE == 15))) {
  
  		input_report_key(input, usage->code, 1);
  
  		/* report missing release event */
  		input_report_key(input, usage->code, 0);
  
  		return 1;
  	}
  
  	return 0;
  }
  
  static const struct hid_device_id saitek_devices[] = {
  	{ HID_USB_DEVICE(USB_VENDOR_ID_SAITEK, USB_DEVICE_ID_SAITEK_PS1000),
  		.driver_data = SAITEK_FIX_PS1000 },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_MADCATZ, USB_DEVICE_ID_MADCATZ_RAT5),
  		.driver_data = SAITEK_RELEASE_MODE_RAT7 },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_SAITEK, USB_DEVICE_ID_SAITEK_RAT7_OLD),
  		.driver_data = SAITEK_RELEASE_MODE_RAT7 },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_SAITEK, USB_DEVICE_ID_SAITEK_RAT7),
  		.driver_data = SAITEK_RELEASE_MODE_RAT7 },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_MADCATZ, USB_DEVICE_ID_MADCATZ_RAT9),
  		.driver_data = SAITEK_RELEASE_MODE_RAT7 },
  	{ HID_USB_DEVICE(USB_VENDOR_ID_SAITEK, USB_DEVICE_ID_SAITEK_MMO7),
  		.driver_data = SAITEK_RELEASE_MODE_MMO7 },
  	{ }
  };
  
  MODULE_DEVICE_TABLE(hid, saitek_devices);
  
  static struct hid_driver saitek_driver = {
  	.name = "saitek",
  	.id_table = saitek_devices,
  	.probe = saitek_probe,
  	.report_fixup = saitek_report_fixup,
  	.raw_event = saitek_raw_event,
  	.event = saitek_event,
  };
  module_hid_driver(saitek_driver);
  
  MODULE_LICENSE("GPL");