aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/hid/hid-lg3ff.c
blob: 4002832ee4af6ce6f6454b387b78b9d13142f2e7 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
/*
 *  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/usb.h>
#include <linux/hid.h>

#include "usbhid/usbhid.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;

/*
 * Maxusage should always be 63 (maximum fields)
 * likely a better way to ensure this data is clean
 */
	memset(report->field[0]->value, 0, sizeof(__s32)*report->field[0]->maxusage);

	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);

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

	usbhid_submit_report(hid, report, USB_DIR_OUT);
}


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 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;
	const signed short *ff_bits = ff3_joystick_ac;
	int error;
	int i;

	/* Find the report to use */
	if (list_empty(report_list)) {
		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) {
		err_hid("NULL output report");
		return -1;
	}

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

	/* 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;

	dev_info(&hid->dev, "Force feedback for Logitech Flight System G940 by "
			"Gary Stein <LordCnidarian@gmail.com>\n");
	return 0;
}