1/*
2 *  Force feedback support for Holtek On Line Grip based gamepads
3 *
4 *  These include at least a Brazilian "Clone Joypad Super Power Fire"
5 *  which uses vendor ID 0x1241 and identifies as "HOLTEK On Line Grip".
6 *
7 *  Copyright (c) 2011 Anssi Hannula <anssi.hannula@iki.fi>
8 */
9
10/*
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 */
25
26#include <linux/hid.h>
27#include <linux/input.h>
28#include <linux/module.h>
29#include <linux/slab.h>
30
31#include "hid-ids.h"
32
33#ifdef CONFIG_HOLTEK_FF
34
35MODULE_LICENSE("GPL");
36MODULE_AUTHOR("Anssi Hannula <anssi.hannula@iki.fi>");
37MODULE_DESCRIPTION("Force feedback support for Holtek On Line Grip based devices");
38
39/*
40 * These commands and parameters are currently known:
41 *
42 * byte 0: command id:
43 * 	01  set effect parameters
44 * 	02  play specified effect
45 * 	03  stop specified effect
46 * 	04  stop all effects
47 * 	06  stop all effects
48 * 	(the difference between 04 and 06 isn't known; win driver
49 * 	 sends 06,04 on application init, and 06 otherwise)
50 *
51 * Commands 01 and 02 need to be sent as pairs, i.e. you need to send 01
52 * before each 02.
53 *
54 * The rest of the bytes are parameters. Command 01 takes all of them, and
55 * commands 02,03 take only the effect id.
56 *
57 * byte 1:
58 *	bits 0-3: effect id:
59 * 		1: very strong rumble
60 * 		2: periodic rumble, short intervals
61 * 		3: very strong rumble
62 * 		4: periodic rumble, long intervals
63 * 		5: weak periodic rumble, long intervals
64 * 		6: weak periodic rumble, short intervals
65 * 		7: periodic rumble, short intervals
66 * 		8: strong periodic rumble, short intervals
67 * 		9: very strong rumble
68 * 		a: causes an error
69 * 		b: very strong periodic rumble, very short intervals
70 * 		c-f: nothing
71 *	bit 6: right (weak) motor enabled
72 *	bit 7: left (strong) motor enabled
73 *
74 * bytes 2-3:  time in milliseconds, big-endian
75 * bytes 5-6:  unknown (win driver seems to use at least 10e0 with effect 1
76 * 		       and 0014 with effect 6)
77 * byte 7:
78 *	bits 0-3: effect magnitude
79 */
80
81#define HOLTEKFF_MSG_LENGTH     7
82
83static const u8 start_effect_1[] = { 0x02, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00 };
84static const u8 stop_all4[] =	   { 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
85static const u8 stop_all6[] =	   { 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
86
87struct holtekff_device {
88	struct hid_field *field;
89};
90
91static void holtekff_send(struct holtekff_device *holtekff,
92			  struct hid_device *hid,
93			  const u8 data[HOLTEKFF_MSG_LENGTH])
94{
95	int i;
96
97	for (i = 0; i < HOLTEKFF_MSG_LENGTH; i++) {
98		holtekff->field->value[i] = data[i];
99	}
100
101	dbg_hid("sending %7ph\n", data);
102
103	hid_hw_request(hid, holtekff->field->report, HID_REQ_SET_REPORT);
104}
105
106static int holtekff_play(struct input_dev *dev, void *data,
107			 struct ff_effect *effect)
108{
109	struct hid_device *hid = input_get_drvdata(dev);
110	struct holtekff_device *holtekff = data;
111	int left, right;
112	/* effect type 1, length 65535 msec */
113	u8 buf[HOLTEKFF_MSG_LENGTH] =
114		{ 0x01, 0x01, 0xff, 0xff, 0x10, 0xe0, 0x00 };
115
116	left = effect->u.rumble.strong_magnitude;
117	right = effect->u.rumble.weak_magnitude;
118	dbg_hid("called with 0x%04x 0x%04x\n", left, right);
119
120	if (!left && !right) {
121		holtekff_send(holtekff, hid, stop_all6);
122		return 0;
123	}
124
125	if (left)
126		buf[1] |= 0x80;
127	if (right)
128		buf[1] |= 0x40;
129
130	/* The device takes a single magnitude, so we just sum them up. */
131	buf[6] = min(0xf, (left >> 12) + (right >> 12));
132
133	holtekff_send(holtekff, hid, buf);
134	holtekff_send(holtekff, hid, start_effect_1);
135
136	return 0;
137}
138
139static int holtekff_init(struct hid_device *hid)
140{
141	struct holtekff_device *holtekff;
142	struct hid_report *report;
143	struct hid_input *hidinput = list_entry(hid->inputs.next,
144						struct hid_input, list);
145	struct list_head *report_list =
146			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
147	struct input_dev *dev = hidinput->input;
148	int error;
149
150	if (list_empty(report_list)) {
151		hid_err(hid, "no output report found\n");
152		return -ENODEV;
153	}
154
155	report = list_entry(report_list->next, struct hid_report, list);
156
157	if (report->maxfield < 1 || report->field[0]->report_count != 7) {
158		hid_err(hid, "unexpected output report layout\n");
159		return -ENODEV;
160	}
161
162	holtekff = kzalloc(sizeof(*holtekff), GFP_KERNEL);
163	if (!holtekff)
164		return -ENOMEM;
165
166	set_bit(FF_RUMBLE, dev->ffbit);
167
168	holtekff->field = report->field[0];
169
170	/* initialize the same way as win driver does */
171	holtekff_send(holtekff, hid, stop_all4);
172	holtekff_send(holtekff, hid, stop_all6);
173
174	error = input_ff_create_memless(dev, holtekff, holtekff_play);
175	if (error) {
176		kfree(holtekff);
177		return error;
178	}
179
180	hid_info(hid, "Force feedback for Holtek On Line Grip based devices by Anssi Hannula <anssi.hannula@iki.fi>\n");
181
182	return 0;
183}
184#else
185static inline int holtekff_init(struct hid_device *hid)
186{
187	return 0;
188}
189#endif
190
191static int holtek_probe(struct hid_device *hdev, const struct hid_device_id *id)
192{
193	int ret;
194
195	ret = hid_parse(hdev);
196	if (ret) {
197		hid_err(hdev, "parse failed\n");
198		goto err;
199	}
200
201	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
202	if (ret) {
203		hid_err(hdev, "hw start failed\n");
204		goto err;
205	}
206
207	holtekff_init(hdev);
208
209	return 0;
210err:
211	return ret;
212}
213
214static const struct hid_device_id holtek_devices[] = {
215	{ HID_USB_DEVICE(USB_VENDOR_ID_HOLTEK, USB_DEVICE_ID_HOLTEK_ON_LINE_GRIP) },
216	{ }
217};
218MODULE_DEVICE_TABLE(hid, holtek_devices);
219
220static struct hid_driver holtek_driver = {
221	.name = "holtek",
222	.id_table = holtek_devices,
223	.probe = holtek_probe,
224};
225module_hid_driver(holtek_driver);
226