1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Force feedback support for Logitech RumblePad and Rumblepad 2
4  *
5  *  Copyright (c) 2008 Anssi Hannula <anssi.hannula@gmail.com>
6  */
7 
8 /*
9  */
10 
11 
12 #include <linux/input.h>
13 #include <linux/slab.h>
14 #include <linux/hid.h>
15 
16 #include "hid-lg.h"
17 
18 struct lg2ff_device {
19 	struct hid_report *report;
20 };
21 
play_effect(struct input_dev * dev,void * data,struct ff_effect * effect)22 static int play_effect(struct input_dev *dev, void *data,
23 			 struct ff_effect *effect)
24 {
25 	struct hid_device *hid = input_get_drvdata(dev);
26 	struct lg2ff_device *lg2ff = data;
27 	int weak, strong;
28 
29 	strong = effect->u.rumble.strong_magnitude;
30 	weak = effect->u.rumble.weak_magnitude;
31 
32 	if (weak || strong) {
33 		weak = weak * 0xff / 0xffff;
34 		strong = strong * 0xff / 0xffff;
35 
36 		lg2ff->report->field[0]->value[0] = 0x51;
37 		lg2ff->report->field[0]->value[2] = weak;
38 		lg2ff->report->field[0]->value[4] = strong;
39 	} else {
40 		lg2ff->report->field[0]->value[0] = 0xf3;
41 		lg2ff->report->field[0]->value[2] = 0x00;
42 		lg2ff->report->field[0]->value[4] = 0x00;
43 	}
44 
45 	hid_hw_request(hid, lg2ff->report, HID_REQ_SET_REPORT);
46 	return 0;
47 }
48 
lg2ff_init(struct hid_device * hid)49 int lg2ff_init(struct hid_device *hid)
50 {
51 	struct lg2ff_device *lg2ff;
52 	struct hid_report *report;
53 	struct hid_input *hidinput;
54 	struct input_dev *dev;
55 	int error;
56 
57 	if (list_empty(&hid->inputs)) {
58 		hid_err(hid, "no inputs found\n");
59 		return -ENODEV;
60 	}
61 	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
62 	dev = hidinput->input;
63 
64 	/* Check that the report looks ok */
65 	report = hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 7);
66 	if (!report)
67 		return -ENODEV;
68 
69 	lg2ff = kmalloc(sizeof(struct lg2ff_device), GFP_KERNEL);
70 	if (!lg2ff)
71 		return -ENOMEM;
72 
73 	set_bit(FF_RUMBLE, dev->ffbit);
74 
75 	error = input_ff_create_memless(dev, lg2ff, play_effect);
76 	if (error) {
77 		kfree(lg2ff);
78 		return error;
79 	}
80 
81 	lg2ff->report = report;
82 	report->field[0]->value[0] = 0xf3;
83 	report->field[0]->value[1] = 0x00;
84 	report->field[0]->value[2] = 0x00;
85 	report->field[0]->value[3] = 0x00;
86 	report->field[0]->value[4] = 0x00;
87 	report->field[0]->value[5] = 0x00;
88 	report->field[0]->value[6] = 0x00;
89 
90 	hid_hw_request(hid, report, HID_REQ_SET_REPORT);
91 
92 	hid_info(hid, "Force feedback for Logitech variant 2 rumble devices by Anssi Hannula <anssi.hannula@gmail.com>\n");
93 
94 	return 0;
95 }
96