Release 4.12 drivers/hid/hid-lg3ff.c
  
  
  
/*
 *  Force feedback support for Logitech Flight System G940
 *
 *  Copyright (c) 2009 Gary Stein <LordCnidarian@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/hid.h>
#include "hid-lg.h"
/*
 * G940 Theory of Operation (from experimentation)
 *
 * There are 63 fields (only 3 of them currently used)
 * 0 - seems to be command field
 * 1 - 30 deal with the x axis
 * 31 -60 deal with the y axis
 *
 * Field 1 is x axis constant force
 * Field 31 is y axis constant force
 *
 * other interesting fields 1,2,3,4 on x axis
 * (same for 31,32,33,34 on y axis)
 *
 * 0 0 127 127 makes the joystick autocenter hard
 *
 * 127 0 127 127 makes the joystick loose on the right,
 * but stops all movemnt left
 *
 * -127 0 -127 -127 makes the joystick loose on the left,
 * but stops all movement right
 *
 * 0 0 -127 -127 makes the joystick rattle very hard
 *
 * I'm sure these are effects that I don't know enough about them
 */
struct lg3ff_device {
	
struct hid_report *report;
};
static int hid_lg3ff_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, y;
/*
 * Available values in the field should always be 63, but we only use up to
 * 35. Instead, clear the entire area, however big it is.
 */
	memset(report->field[0]->value, 0,
	       sizeof(__s32) * report->field[0]->report_count);
	switch (effect->type) {
	case FF_CONSTANT:
/*
 * Already clamped in ff_memless
 * 0 is center (different then other logitech)
 */
		x = effect->u.ramp.start_level;
		y = effect->u.ramp.end_level;
		/* send command byte */
		report->field[0]->value[0] = 0x51;
/*
 * Sign backwards from other Force3d pro
 * which get recast here in two's complement 8 bits
 */
		report->field[0]->value[1] = (unsigned char)(-x);
		report->field[0]->value[31] = (unsigned char)(-y);
		hid_hw_request(hid, report, HID_REQ_SET_REPORT);
		break;
	}
	return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Gary Stein | 195 | 97.99% | 1 | 33.33% | 
| Benjamin Tissoires | 2 | 1.01% | 1 | 33.33% | 
| Kees Cook | 2 | 1.01% | 1 | 33.33% | 
| Total | 199 | 100.00% | 3 | 100.00% | 
static void hid_lg3ff_set_autocenter(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);
/*
 * Auto Centering probed from device
 * NOTE: deadman's switch on G940 must be covered
 * for effects to work
 */
	report->field[0]->value[0] = 0x51;
	report->field[0]->value[1] = 0x00;
	report->field[0]->value[2] = 0x00;
	report->field[0]->value[3] = 0x7F;
	report->field[0]->value[4] = 0x7F;
	report->field[0]->value[31] = 0x00;
	report->field[0]->value[32] = 0x00;
	report->field[0]->value[33] = 0x7F;
	report->field[0]->value[34] = 0x7F;
	hid_hw_request(hid, report, HID_REQ_SET_REPORT);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Gary Stein | 190 | 98.96% | 1 | 50.00% | 
| Benjamin Tissoires | 2 | 1.04% | 1 | 50.00% | 
| Total | 192 | 100.00% | 2 | 100.00% | 
static const signed short ff3_joystick_ac[] = {
	FF_CONSTANT,
	FF_AUTOCENTER,
	-1
};
int lg3ff_init(struct hid_device *hid)
{
	struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
	struct input_dev *dev = hidinput->input;
	const signed short *ff_bits = ff3_joystick_ac;
	int error;
	int i;
	/* Check that the report looks ok */
	if (!hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 35))
		return -ENODEV;
	/* Assume single fixed device G940 */
	for (i = 0; ff_bits[i] >= 0; i++)
		set_bit(ff_bits[i], dev->ffbit);
	error = input_ff_create_memless(dev, NULL, hid_lg3ff_play);
	if (error)
		return error;
	if (test_bit(FF_AUTOCENTER, dev->ffbit))
		dev->ff->set_autocenter = hid_lg3ff_set_autocenter;
	hid_info(hid, "Force feedback for Logitech Flight System G940 by Gary Stein <LordCnidarian@gmail.com>\n");
	return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Gary Stein | 136 | 91.28% | 1 | 33.33% | 
| Kees Cook | 8 | 5.37% | 1 | 33.33% | 
| Joe Perches | 5 | 3.36% | 1 | 33.33% | 
| Total | 149 | 100.00% | 3 | 100.00% | 
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Gary Stein | 559 | 96.71% | 1 | 25.00% | 
| Kees Cook | 10 | 1.73% | 1 | 25.00% | 
| Joe Perches | 5 | 0.87% | 1 | 25.00% | 
| Benjamin Tissoires | 4 | 0.69% | 1 | 25.00% | 
| Total | 578 | 100.00% | 4 | 100.00% | 
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