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/module.h>
27
28 #include "hid-ids.h"
29
30 struct emsff_device {
31 struct hid_report *report;
32 };
33
emsff_play(struct input_dev * dev,void * data,struct ff_effect * effect)34 static int emsff_play(struct input_dev *dev, void *data,
35 struct ff_effect *effect)
36 {
37 struct hid_device *hid = input_get_drvdata(dev);
38 struct emsff_device *emsff = data;
39 int weak, strong;
40
41 weak = effect->u.rumble.weak_magnitude;
42 strong = effect->u.rumble.strong_magnitude;
43
44 dbg_hid("called with 0x%04x 0x%04x\n", strong, weak);
45
46 weak = weak * 0xff / 0xffff;
47 strong = strong * 0xff / 0xffff;
48
49 emsff->report->field[0]->value[1] = weak;
50 emsff->report->field[0]->value[2] = strong;
51
52 dbg_hid("running with 0x%02x 0x%02x\n", strong, weak);
53 hid_hw_request(hid, emsff->report, HID_REQ_SET_REPORT);
54
55 return 0;
56 }
57
emsff_init(struct hid_device * hid)58 static int emsff_init(struct hid_device *hid)
59 {
60 struct emsff_device *emsff;
61 struct hid_report *report;
62 struct hid_input *hidinput;
63 struct list_head *report_list =
64 &hid->report_enum[HID_OUTPUT_REPORT].report_list;
65 struct input_dev *dev;
66 int error;
67
68 if (list_empty(&hid->inputs)) {
69 hid_err(hid, "no inputs found\n");
70 return -ENODEV;
71 }
72 hidinput = list_first_entry(&hid->inputs, struct hid_input, list);
73 dev = hidinput->input;
74
75 if (list_empty(report_list)) {
76 hid_err(hid, "no output reports found\n");
77 return -ENODEV;
78 }
79
80 report = list_first_entry(report_list, struct hid_report, list);
81 if (report->maxfield < 1) {
82 hid_err(hid, "no fields in the report\n");
83 return -ENODEV;
84 }
85
86 if (report->field[0]->report_count < 7) {
87 hid_err(hid, "not enough values in the field\n");
88 return -ENODEV;
89 }
90
91 emsff = kzalloc(sizeof(struct emsff_device), GFP_KERNEL);
92 if (!emsff)
93 return -ENOMEM;
94
95 set_bit(FF_RUMBLE, dev->ffbit);
96
97 error = input_ff_create_memless(dev, emsff, emsff_play);
98 if (error) {
99 kfree(emsff);
100 return error;
101 }
102
103 emsff->report = report;
104 emsff->report->field[0]->value[0] = 0x01;
105 emsff->report->field[0]->value[1] = 0x00;
106 emsff->report->field[0]->value[2] = 0x00;
107 emsff->report->field[0]->value[3] = 0x00;
108 emsff->report->field[0]->value[4] = 0x00;
109 emsff->report->field[0]->value[5] = 0x00;
110 emsff->report->field[0]->value[6] = 0x00;
111 hid_hw_request(hid, emsff->report, HID_REQ_SET_REPORT);
112
113 hid_info(hid, "force feedback for EMS based devices by Ignaz Forster <ignaz.forster@gmx.de>\n");
114
115 return 0;
116 }
117
ems_probe(struct hid_device * hdev,const struct hid_device_id * id)118 static int ems_probe(struct hid_device *hdev, const struct hid_device_id *id)
119 {
120 int ret;
121
122 ret = hid_parse(hdev);
123 if (ret) {
124 hid_err(hdev, "parse failed\n");
125 goto err;
126 }
127
128 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
129 if (ret) {
130 hid_err(hdev, "hw start failed\n");
131 goto err;
132 }
133
134 ret = emsff_init(hdev);
135 if (ret) {
136 dev_err(&hdev->dev, "force feedback init failed\n");
137 hid_hw_stop(hdev);
138 goto err;
139 }
140
141 return 0;
142 err:
143 return ret;
144 }
145
146 static const struct hid_device_id ems_devices[] = {
147 { HID_USB_DEVICE(USB_VENDOR_ID_EMS, USB_DEVICE_ID_EMS_TRIO_LINKER_PLUS_II) },
148 { }
149 };
150 MODULE_DEVICE_TABLE(hid, ems_devices);
151
152 static struct hid_driver ems_driver = {
153 .name = "hkems",
154 .id_table = ems_devices,
155 .probe = ems_probe,
156 };
157 module_hid_driver(ems_driver);
158
159 MODULE_LICENSE("GPL");
160
161