/*
   *  Force feedback support for Logitech Speed Force Wireless
   *
   *  http://wiibrew.org/wiki/Logitech_USB_steering_wheel
   *
   *  Copyright (c) 2010 Simon Wood <simon@mungewell.org>
   */
  
  /*
   * 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/usb.h>
  #include <linux/hid.h>
  
  #include "usbhid/usbhid.h"
  #include "hid-lg.h"

  #include "hid-ids.h"

  #define DFGT_REV_MAJ 0x13
  #define DFGT_REV_MIN 0x22
  #define DFP_REV_MAJ 0x11
  #define DFP_REV_MIN 0x06
  #define FFEX_REV_MAJ 0x21
  #define FFEX_REV_MIN 0x00
  #define G25_REV_MAJ 0x12
  #define G25_REV_MIN 0x22
  #define G27_REV_MAJ 0x12
  #define G27_REV_MIN 0x38

  #define to_hid_device(pdev) container_of(pdev, struct hid_device, dev)
  
  static void hid_lg4ff_set_range_dfp(struct hid_device *hid, u16 range);
  static void hid_lg4ff_set_range_g25(struct hid_device *hid, u16 range);
  static ssize_t lg4ff_range_show(struct device *dev, struct device_attribute *attr, char *buf);
  static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count);
  
  static DEVICE_ATTR(range, S_IRWXU | S_IRWXG | S_IRWXO, lg4ff_range_show, lg4ff_range_store);
  
  static bool list_inited;
  
  struct lg4ff_device_entry {
  	char  *device_id;	/* Use name in respective kobject structure's address as the ID */
  	__u16 range;
  	__u16 min_range;
  	__u16 max_range;
  	__u8  leds;
  	struct list_head list;
  	void (*set_range)(struct hid_device *hid, u16 range);
  };
  
  static struct lg4ff_device_entry device_list;

  static const signed short lg4ff_wheel_effects[] = {

  	FF_CONSTANT,
  	FF_AUTOCENTER,
  	-1
  };

  struct lg4ff_wheel {
  	const __u32 product_id;
  	const signed short *ff_effects;
  	const __u16 min_range;
  	const __u16 max_range;

  	void (*set_range)(struct hid_device *hid, u16 range);

  };
  
  static const struct lg4ff_wheel lg4ff_devices[] = {

  	{USB_DEVICE_ID_LOGITECH_WHEEL,       lg4ff_wheel_effects, 40, 270, NULL},
  	{USB_DEVICE_ID_LOGITECH_MOMO_WHEEL,  lg4ff_wheel_effects, 40, 270, NULL},
  	{USB_DEVICE_ID_LOGITECH_DFP_WHEEL,   lg4ff_wheel_effects, 40, 900, hid_lg4ff_set_range_dfp},
  	{USB_DEVICE_ID_LOGITECH_G25_WHEEL,   lg4ff_wheel_effects, 40, 900, hid_lg4ff_set_range_g25},
  	{USB_DEVICE_ID_LOGITECH_DFGT_WHEEL,  lg4ff_wheel_effects, 40, 900, hid_lg4ff_set_range_g25},
  	{USB_DEVICE_ID_LOGITECH_G27_WHEEL,   lg4ff_wheel_effects, 40, 900, hid_lg4ff_set_range_g25},
  	{USB_DEVICE_ID_LOGITECH_MOMO_WHEEL2, lg4ff_wheel_effects, 40, 270, NULL},
  	{USB_DEVICE_ID_LOGITECH_WII_WHEEL,   lg4ff_wheel_effects, 40, 270, NULL}

  };

  struct lg4ff_native_cmd {
  	const __u8 cmd_num;	/* Number of commands to send */
  	const __u8 cmd[];
  };
  
  struct lg4ff_usb_revision {
  	const __u16 rev_maj;
  	const __u16 rev_min;
  	const struct lg4ff_native_cmd *command;
  };
  
  static const struct lg4ff_native_cmd native_dfp = {
  	1,
  	{0xf8, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00}
  };
  
  static const struct lg4ff_native_cmd native_dfgt = {
  	2,
  	{0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 1st command */
  	 0xf8, 0x09, 0x03, 0x01, 0x00, 0x00, 0x00}	/* 2nd command */
  };
  
  static const struct lg4ff_native_cmd native_g25 = {
  	1,
  	{0xf8, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00}
  };
  
  static const struct lg4ff_native_cmd native_g27 = {
  	2,
  	{0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 1st command */
  	 0xf8, 0x09, 0x04, 0x01, 0x00, 0x00, 0x00}	/* 2nd command */
  };
  
  static const struct lg4ff_usb_revision lg4ff_revs[] = {
  	{DFGT_REV_MAJ, DFGT_REV_MIN, &native_dfgt},	/* Driving Force GT */
  	{DFP_REV_MAJ,  DFP_REV_MIN,  &native_dfp},	/* Driving Force Pro */
  	{G25_REV_MAJ,  G25_REV_MIN,  &native_g25},	/* G25 */
  	{G27_REV_MAJ,  G27_REV_MIN,  &native_g27},	/* G27 */
  };

  static int hid_lg4ff_play(struct input_dev *dev, void *data, struct ff_effect *effect)

  {
  	struct hid_device *hid = input_get_drvdata(dev);
  	struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  	struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
  	int x;
  
  #define CLAMP(x) if (x < 0) x = 0; if (x > 0xff) x = 0xff
  
  	switch (effect->type) {
  	case FF_CONSTANT:
  		x = effect->u.ramp.start_level + 0x80;	/* 0x80 is no force */
  		CLAMP(x);
  		report->field[0]->value[0] = 0x11;	/* Slot 1 */

  		report->field[0]->value[1] = 0x08;

  		report->field[0]->value[2] = x;

  		report->field[0]->value[3] = 0x80;

  		report->field[0]->value[4] = 0x00;

  		report->field[0]->value[5] = 0x00;

  		report->field[0]->value[6] = 0x00;

  
  		usbhid_submit_report(hid, report, USB_DIR_OUT);
  		break;
  	}
  	return 0;
  }

  /* Sends default autocentering command compatible with
   * all wheels except Formula Force EX */
  static void hid_lg4ff_set_autocenter_default(struct input_dev *dev, u16 magnitude)

  {
  	struct hid_device *hid = input_get_drvdata(dev);
  	struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  	struct hid_report *report = list_entry(report_list->next, struct hid_report, list);

  	report->field[0]->value[0] = 0xfe;
  	report->field[0]->value[1] = 0x0d;
  	report->field[0]->value[2] = magnitude >> 13;
  	report->field[0]->value[3] = magnitude >> 13;
  	report->field[0]->value[4] = magnitude >> 8;
  	report->field[0]->value[5] = 0x00;
  	report->field[0]->value[6] = 0x00;

  
  	usbhid_submit_report(hid, report, USB_DIR_OUT);
  }

  /* Sends autocentering command compatible with Formula Force EX */
  static void hid_lg4ff_set_autocenter_ffex(struct input_dev *dev, u16 magnitude)
  {
  	struct hid_device *hid = input_get_drvdata(dev);
  	struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  	struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
  	magnitude = magnitude * 90 / 65535;
  	
  
  	report->field[0]->value[0] = 0xfe;
  	report->field[0]->value[1] = 0x03;
  	report->field[0]->value[2] = magnitude >> 14;
  	report->field[0]->value[3] = magnitude >> 14;
  	report->field[0]->value[4] = magnitude;
  	report->field[0]->value[5] = 0x00;
  	report->field[0]->value[6] = 0x00;
  
  	usbhid_submit_report(hid, report, USB_DIR_OUT);
  }

  /* Sends command to set range compatible with G25/G27/Driving Force GT */
  static void hid_lg4ff_set_range_g25(struct hid_device *hid, u16 range)
  {
  	struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  	struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
  	dbg_hid("G25/G27/DFGT: setting range to %u
  ", range);
  
  	report->field[0]->value[0] = 0xf8;
  	report->field[0]->value[1] = 0x81;
  	report->field[0]->value[2] = range & 0x00ff;
  	report->field[0]->value[3] = (range & 0xff00) >> 8;
  	report->field[0]->value[4] = 0x00;
  	report->field[0]->value[5] = 0x00;
  	report->field[0]->value[6] = 0x00;
  
  	usbhid_submit_report(hid, report, USB_DIR_OUT);
  }
  
  /* Sends commands to set range compatible with Driving Force Pro wheel */
  static void hid_lg4ff_set_range_dfp(struct hid_device *hid, __u16 range)
  {
  	struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  	struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
  	int start_left, start_right, full_range;
  	dbg_hid("Driving Force Pro: setting range to %u
  ", range);
  
  	/* Prepare "coarse" limit command */
  	report->field[0]->value[0] = 0xf8;
  	report->field[0]->value[1] = 0x00; 	/* Set later */
  	report->field[0]->value[2] = 0x00;
  	report->field[0]->value[3] = 0x00;
  	report->field[0]->value[4] = 0x00;
  	report->field[0]->value[5] = 0x00;
  	report->field[0]->value[6] = 0x00;
  
  	if (range > 200) {
  		report->field[0]->value[1] = 0x03;
  		full_range = 900;
  	} else {
  		report->field[0]->value[1] = 0x02;
  		full_range = 200;
  	}
  	usbhid_submit_report(hid, report, USB_DIR_OUT);
  
  	/* Prepare "fine" limit command */
  	report->field[0]->value[0] = 0x81;
  	report->field[0]->value[1] = 0x0b;
  	report->field[0]->value[2] = 0x00;
  	report->field[0]->value[3] = 0x00;
  	report->field[0]->value[4] = 0x00;
  	report->field[0]->value[5] = 0x00;
  	report->field[0]->value[6] = 0x00;
  
  	if (range == 200 || range == 900) {	/* Do not apply any fine limit */
  		usbhid_submit_report(hid, report, USB_DIR_OUT);
  		return;
  	}
  
  	/* Construct fine limit command */
  	start_left = (((full_range - range + 1) * 2047) / full_range);
  	start_right = 0xfff - start_left;
  
  	report->field[0]->value[2] = start_left >> 4;
  	report->field[0]->value[3] = start_right >> 4;
  	report->field[0]->value[4] = 0xff;
  	report->field[0]->value[5] = (start_right & 0xe) << 4 | (start_left & 0xe);
  	report->field[0]->value[6] = 0xff;
  
  	usbhid_submit_report(hid, report, USB_DIR_OUT);
  }

  static void hid_lg4ff_switch_native(struct hid_device *hid, const struct lg4ff_native_cmd *cmd)
  {
  	struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  	struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
  	__u8 i, j;
  
  	j = 0;
  	while (j < 7*cmd->cmd_num) {
  		for (i = 0; i < 7; i++)
  			report->field[0]->value[i] = cmd->cmd[j++];
  
  		usbhid_submit_report(hid, report, USB_DIR_OUT);
  	}
  }

  /* Read current range and display it in terminal */
  static ssize_t lg4ff_range_show(struct device *dev, struct device_attribute *attr, char *buf)
  {

  	struct lg4ff_device_entry *uninitialized_var(entry);

  	struct list_head *h;
  	struct hid_device *hid = to_hid_device(dev);
  	size_t count;
  
  	list_for_each(h, &device_list.list) {
  		entry = list_entry(h, struct lg4ff_device_entry, list);
  		if (strcmp(entry->device_id, (&hid->dev)->kobj.name) == 0)
  			break;
  	}
  	if (h == &device_list.list) {
  		dbg_hid("Device not found!");
  		return 0;
  	}
  
  	count = scnprintf(buf, PAGE_SIZE, "%u
  ", entry->range);
  	return count;
  }
  
  /* Set range to user specified value, call appropriate function
   * according to the type of the wheel */
  static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
  {

  	struct lg4ff_device_entry *uninitialized_var(entry);

  	struct list_head *h;
  	struct hid_device *hid = to_hid_device(dev);
  	__u16 range = simple_strtoul(buf, NULL, 10);
  
  	list_for_each(h, &device_list.list) {
  		entry = list_entry(h, struct lg4ff_device_entry, list);
  		if (strcmp(entry->device_id, (&hid->dev)->kobj.name) == 0)
  			break;
  	}
  	if (h == &device_list.list) {
  		dbg_hid("Device not found!");
  		return count;
  	}
  
  	if (range == 0)
  		range = entry->max_range;
  
  	/* Check if the wheel supports range setting
  	 * and that the range is within limits for the wheel */
  	if (entry->set_range != NULL && range >= entry->min_range && range <= entry->max_range) {
  		entry->set_range(hid, range);
  		entry->range = range;
  	}
  
  	return count;
  }

  int lg4ff_init(struct hid_device *hid)
  {
  	struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
  	struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  	struct input_dev *dev = hidinput->input;
  	struct hid_report *report;
  	struct hid_field *field;

  	struct lg4ff_device_entry *entry;
  	struct usb_device_descriptor *udesc;

  	int error, i, j;

  	__u16 bcdDevice, rev_maj, rev_min;

  
  	/* Find the report to use */
  	if (list_empty(report_list)) {

  		hid_err(hid, "No output report found
  ");

  		return -1;
  	}
  
  	/* Check that the report looks ok */
  	report = list_entry(report_list->next, struct hid_report, list);
  	if (!report) {

  		hid_err(hid, "NULL output report
  ");

  		return -1;
  	}
  
  	field = report->field[0];
  	if (!field) {

  		hid_err(hid, "NULL field
  ");

  		return -1;
  	}

  	/* Check what wheel has been connected */
  	for (i = 0; i < ARRAY_SIZE(lg4ff_devices); i++) {
  		if (hid->product == lg4ff_devices[i].product_id) {
  			dbg_hid("Found compatible device, product ID %04X
  ", lg4ff_devices[i].product_id);
  			break;
  		}
  	}
  
  	if (i == ARRAY_SIZE(lg4ff_devices)) {
  		hid_err(hid, "Device is not supported by lg4ff driver. If you think it should be, consider reporting a bug to"
  			     "LKML, Simon Wood <simon@mungewell.org> or Michal Maly <madcatxster@gmail.com>
  ");
  		return -1;
  	}

  	/* Attempt to switch wheel to native mode when applicable */
  	udesc = &(hid_to_usb_dev(hid)->descriptor);
  	if (!udesc) {
  		hid_err(hid, "NULL USB device descriptor
  ");
  		return -1;
  	}
  	bcdDevice = le16_to_cpu(udesc->bcdDevice);
  	rev_maj = bcdDevice >> 8;
  	rev_min = bcdDevice & 0xff;
  
  	if (lg4ff_devices[i].product_id == USB_DEVICE_ID_LOGITECH_WHEEL) {
  		dbg_hid("Generic wheel detected, can it do native?
  ");
  		dbg_hid("USB revision: %2x.%02x
  ", rev_maj, rev_min);
  
  		for (j = 0; j < ARRAY_SIZE(lg4ff_revs); j++) {
  			if (lg4ff_revs[j].rev_maj == rev_maj && lg4ff_revs[j].rev_min == rev_min) {
  				hid_lg4ff_switch_native(hid, lg4ff_revs[j].command);
  				hid_info(hid, "Switched to native mode
  ");
  			}
  		}
  	}

  	/* Set supported force feedback capabilities */
  	for (j = 0; lg4ff_devices[i].ff_effects[j] >= 0; j++)
  		set_bit(lg4ff_devices[i].ff_effects[j], dev->ffbit);

  
  	error = input_ff_create_memless(dev, NULL, hid_lg4ff_play);
  
  	if (error)
  		return error;

  	/* Check if autocentering is available and
  	 * set the centering force to zero by default */
  	if (test_bit(FF_AUTOCENTER, dev->ffbit)) {
  		if(rev_maj == FFEX_REV_MAJ && rev_min == FFEX_REV_MIN)	/* Formula Force EX expects different autocentering command */
  			dev->ff->set_autocenter = hid_lg4ff_set_autocenter_ffex;
  		else
  			dev->ff->set_autocenter = hid_lg4ff_set_autocenter_default;
  
  		dev->ff->set_autocenter(dev, 0);
  	}

  		/* Initialize device_list if this is the first device to handle by lg4ff */
  	if (!list_inited) {
  		INIT_LIST_HEAD(&device_list.list);
  		list_inited = 1;
  	}
  
  	/* Add the device to device_list */

  	entry = kzalloc(sizeof(struct lg4ff_device_entry), GFP_KERNEL);

  	if (!entry) {
  		hid_err(hid, "Cannot add device, insufficient memory.
  ");
  		return -ENOMEM;
  	}

  	entry->device_id = kstrdup((&hid->dev)->kobj.name, GFP_KERNEL);

  	if (!entry->device_id) {
  		hid_err(hid, "Cannot set device_id, insufficient memory.
  ");

  		kfree(entry);

  		return -ENOMEM;
  	}

  	entry->min_range = lg4ff_devices[i].min_range;
  	entry->max_range = lg4ff_devices[i].max_range;
  	entry->set_range = lg4ff_devices[i].set_range;
  	list_add(&entry->list, &device_list.list);
  
  	/* Create sysfs interface */
  	error = device_create_file(&hid->dev, &dev_attr_range);
  	if (error)
  		return error;
  	dbg_hid("sysfs interface created
  ");
  
  	/* Set the maximum range to start with */
  	entry->range = entry->max_range;
  	if (entry->set_range != NULL)
  		entry->set_range(hid, entry->range);

  	hid_info(hid, "Force feedback for Logitech Speed Force Wireless by Simon Wood <simon@mungewell.org>
  ");

  	return 0;
  }

  int lg4ff_deinit(struct hid_device *hid)
  {
  	bool found = 0;
  	struct lg4ff_device_entry *entry;
  	struct list_head *h, *g;
  	list_for_each_safe(h, g, &device_list.list) {
  		entry = list_entry(h, struct lg4ff_device_entry, list);
  		if (strcmp(entry->device_id, (&hid->dev)->kobj.name) == 0) {
  			list_del(h);
  			kfree(entry->device_id);
  			kfree(entry);
  			found = 1;
  			break;
  		}
  	}
  
  	if (!found) {
  		dbg_hid("Device entry not found!
  ");
  		return -1;
  	}
  
  	device_remove_file(&hid->dev, &dev_attr_range);
  	dbg_hid("Device successfully unregistered
  ");
  	return 0;
  }