summaryrefslogtreecommitdiff
path: root/drivers/hid/hid-lg3ff.c
blob: 109735b89b7a46385f3087175b008badfc681057 (plain)
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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Force feedback support for Logitech Flight System G940
 *
 *  Copyright (c) 2009 Gary Stein <LordCnidarian@gmail.com>
 */

/*
 */


#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
 */

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;
}
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);
}


static const signed short ff3_joystick_ac[] = {
	FF_CONSTANT,
	FF_AUTOCENTER,
	-1
};

int lg3ff_init(struct hid_device *hid)
{
	struct hid_input *hidinput;
	struct input_dev *dev;
	const signed short *ff_bits = ff3_joystick_ac;
	int error;
	int i;

	if (list_empty(&hid->inputs)) {
		hid_err(hid, "no inputs found\n");
		return -ENODEV;
	}
	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
	dev = hidinput->input;

	/* 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;
}