cregit-Linux how code gets into the kernel

Release 4.7 drivers/hid/hid-lg3ff.c

Directory: drivers/hid
/*
 *  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

PersonTokensPropCommitsCommitProp
gary steingary stein19597.99%133.33%
kees cookkees cook21.01%133.33%
benjamin tissoiresbenjamin tissoires21.01%133.33%
Total199100.00%3100.00%


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

PersonTokensPropCommitsCommitProp
gary steingary stein19098.96%150.00%
benjamin tissoiresbenjamin tissoires21.04%150.00%
Total192100.00%2100.00%

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

PersonTokensPropCommitsCommitProp
gary steingary stein13691.28%133.33%
kees cookkees cook85.37%133.33%
joe perchesjoe perches53.36%133.33%
Total149100.00%3100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
gary steingary stein55996.71%125.00%
kees cookkees cook101.73%125.00%
joe perchesjoe perches50.87%125.00%
benjamin tissoiresbenjamin tissoires40.69%125.00%
Total578100.00%4100.00%
Directory: drivers/hid
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