1/*
2 *  Force feedback support for EMS Trio Linker Plus II
3 *
4 *  Copyright (c) 2010 Ignaz Forster <ignaz.forster@gmx.de>
5 */
6
7/*
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23
24#include <linux/hid.h>
25#include <linux/input.h>
26#include <linux/usb.h>
27#include <linux/module.h>
28
29#include "hid-ids.h"
30#include "usbhid/usbhid.h"
31
32struct emsff_device {
33	struct hid_report *report;
34};
35
36static int emsff_play(struct input_dev *dev, void *data,
37			 struct ff_effect *effect)
38{
39	struct hid_device *hid = input_get_drvdata(dev);
40	struct emsff_device *emsff = data;
41	int weak, strong;
42
43	weak = effect->u.rumble.weak_magnitude;
44	strong = effect->u.rumble.strong_magnitude;
45
46	dbg_hid("called with 0x%04x 0x%04x\n", strong, weak);
47
48	weak = weak * 0xff / 0xffff;
49	strong = strong * 0xff / 0xffff;
50
51	emsff->report->field[0]->value[1] = weak;
52	emsff->report->field[0]->value[2] = strong;
53
54	dbg_hid("running with 0x%02x 0x%02x\n", strong, weak);
55	usbhid_submit_report(hid, emsff->report, USB_DIR_OUT);
56
57	return 0;
58}
59
60static int emsff_init(struct hid_device *hid)
61{
62	struct emsff_device *emsff;
63	struct hid_report *report;
64	struct hid_input *hidinput = list_first_entry(&hid->inputs,
65						struct hid_input, list);
66	struct list_head *report_list =
67			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
68	struct input_dev *dev = hidinput->input;
69	int error;
70
71	if (list_empty(report_list)) {
72		hid_err(hid, "no output reports found\n");
73		return -ENODEV;
74	}
75
76	report = list_first_entry(report_list, struct hid_report, list);
77	if (report->maxfield < 1) {
78		hid_err(hid, "no fields in the report\n");
79		return -ENODEV;
80	}
81
82	if (report->field[0]->report_count < 7) {
83		hid_err(hid, "not enough values in the field\n");
84		return -ENODEV;
85	}
86
87	emsff = kzalloc(sizeof(struct emsff_device), GFP_KERNEL);
88	if (!emsff)
89		return -ENOMEM;
90
91	set_bit(FF_RUMBLE, dev->ffbit);
92
93	error = input_ff_create_memless(dev, emsff, emsff_play);
94	if (error) {
95		kfree(emsff);
96		return error;
97	}
98
99	emsff->report = report;
100	emsff->report->field[0]->value[0] = 0x01;
101	emsff->report->field[0]->value[1] = 0x00;
102	emsff->report->field[0]->value[2] = 0x00;
103	emsff->report->field[0]->value[3] = 0x00;
104	emsff->report->field[0]->value[4] = 0x00;
105	emsff->report->field[0]->value[5] = 0x00;
106	emsff->report->field[0]->value[6] = 0x00;
107	usbhid_submit_report(hid, emsff->report, USB_DIR_OUT);
108
109	hid_info(hid, "force feedback for EMS based devices by Ignaz Forster <ignaz.forster@gmx.de>\n");
110
111	return 0;
112}
113
114static int ems_probe(struct hid_device *hdev, const struct hid_device_id *id)
115{
116	int ret;
117
118	ret = hid_parse(hdev);
119	if (ret) {
120		hid_err(hdev, "parse failed\n");
121		goto err;
122	}
123
124	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
125	if (ret) {
126		hid_err(hdev, "hw start failed\n");
127		goto err;
128	}
129
130	ret = emsff_init(hdev);
131	if (ret) {
132		dev_err(&hdev->dev, "force feedback init failed\n");
133		hid_hw_stop(hdev);
134		goto err;
135	}
136
137	return 0;
138err:
139	return ret;
140}
141
142static const struct hid_device_id ems_devices[] = {
143	{ HID_USB_DEVICE(USB_VENDOR_ID_EMS, USB_DEVICE_ID_EMS_TRIO_LINKER_PLUS_II) },
144	{ }
145};
146MODULE_DEVICE_TABLE(hid, ems_devices);
147
148static struct hid_driver ems_driver = {
149	.name = "hkems",
150	.id_table = ems_devices,
151	.probe = ems_probe,
152};
153
154static int ems_init(void)
155{
156	return hid_register_driver(&ems_driver);
157}
158
159static void ems_exit(void)
160{
161	hid_unregister_driver(&ems_driver);
162}
163
164module_init(ems_init);
165module_exit(ems_exit);
166MODULE_LICENSE("GPL");
167
168