1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  Force feedback support for Holtek On Line Grip based gamepads
4 *
5 *  These include at least a Brazilian "Clone Joypad Super Power Fire"
6 *  which uses vendor ID 0x1241 and identifies as "HOLTEK On Line Grip".
7 *
8 *  Copyright (c) 2011 Anssi Hannula <anssi.hannula@iki.fi>
9 */
10
11/*
12 */
13
14#include <linux/hid.h>
15#include <linux/input.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18
19#include "hid-ids.h"
20
21#ifdef CONFIG_HOLTEK_FF
22
23/*
24 * These commands and parameters are currently known:
25 *
26 * byte 0: command id:
27 * 	01  set effect parameters
28 * 	02  play specified effect
29 * 	03  stop specified effect
30 * 	04  stop all effects
31 * 	06  stop all effects
32 * 	(the difference between 04 and 06 isn't known; win driver
33 * 	 sends 06,04 on application init, and 06 otherwise)
34 *
35 * Commands 01 and 02 need to be sent as pairs, i.e. you need to send 01
36 * before each 02.
37 *
38 * The rest of the bytes are parameters. Command 01 takes all of them, and
39 * commands 02,03 take only the effect id.
40 *
41 * byte 1:
42 *	bits 0-3: effect id:
43 * 		1: very strong rumble
44 * 		2: periodic rumble, short intervals
45 * 		3: very strong rumble
46 * 		4: periodic rumble, long intervals
47 * 		5: weak periodic rumble, long intervals
48 * 		6: weak periodic rumble, short intervals
49 * 		7: periodic rumble, short intervals
50 * 		8: strong periodic rumble, short intervals
51 * 		9: very strong rumble
52 * 		a: causes an error
53 * 		b: very strong periodic rumble, very short intervals
54 * 		c-f: nothing
55 *	bit 6: right (weak) motor enabled
56 *	bit 7: left (strong) motor enabled
57 *
58 * bytes 2-3:  time in milliseconds, big-endian
59 * bytes 5-6:  unknown (win driver seems to use at least 10e0 with effect 1
60 * 		       and 0014 with effect 6)
61 * byte 7:
62 *	bits 0-3: effect magnitude
63 */
64
65#define HOLTEKFF_MSG_LENGTH     7
66
67static const u8 start_effect_1[] = { 0x02, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00 };
68static const u8 stop_all4[] =	   { 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
69static const u8 stop_all6[] =	   { 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
70
71struct holtekff_device {
72	struct hid_field *field;
73};
74
75static void holtekff_send(struct holtekff_device *holtekff,
76			  struct hid_device *hid,
77			  const u8 data[HOLTEKFF_MSG_LENGTH])
78{
79	int i;
80
81	for (i = 0; i < HOLTEKFF_MSG_LENGTH; i++) {
82		holtekff->field->value[i] = data[i];
83	}
84
85	dbg_hid("sending %7ph\n", data);
86
87	hid_hw_request(hid, holtekff->field->report, HID_REQ_SET_REPORT);
88}
89
90static int holtekff_play(struct input_dev *dev, void *data,
91			 struct ff_effect *effect)
92{
93	struct hid_device *hid = input_get_drvdata(dev);
94	struct holtekff_device *holtekff = data;
95	int left, right;
96	/* effect type 1, length 65535 msec */
97	u8 buf[HOLTEKFF_MSG_LENGTH] =
98		{ 0x01, 0x01, 0xff, 0xff, 0x10, 0xe0, 0x00 };
99
100	left = effect->u.rumble.strong_magnitude;
101	right = effect->u.rumble.weak_magnitude;
102	dbg_hid("called with 0x%04x 0x%04x\n", left, right);
103
104	if (!left && !right) {
105		holtekff_send(holtekff, hid, stop_all6);
106		return 0;
107	}
108
109	if (left)
110		buf[1] |= 0x80;
111	if (right)
112		buf[1] |= 0x40;
113
114	/* The device takes a single magnitude, so we just sum them up. */
115	buf[6] = min(0xf, (left >> 12) + (right >> 12));
116
117	holtekff_send(holtekff, hid, buf);
118	holtekff_send(holtekff, hid, start_effect_1);
119
120	return 0;
121}
122
123static int holtekff_init(struct hid_device *hid)
124{
125	struct holtekff_device *holtekff;
126	struct hid_report *report;
127	struct hid_input *hidinput;
128	struct list_head *report_list =
129			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
130	struct input_dev *dev;
131	int error;
132
133	if (list_empty(&hid->inputs)) {
134		hid_err(hid, "no inputs found\n");
135		return -ENODEV;
136	}
137	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
138	dev = hidinput->input;
139
140	if (list_empty(report_list)) {
141		hid_err(hid, "no output report found\n");
142		return -ENODEV;
143	}
144
145	report = list_entry(report_list->next, struct hid_report, list);
146
147	if (report->maxfield < 1 || report->field[0]->report_count != 7) {
148		hid_err(hid, "unexpected output report layout\n");
149		return -ENODEV;
150	}
151
152	holtekff = kzalloc(sizeof(*holtekff), GFP_KERNEL);
153	if (!holtekff)
154		return -ENOMEM;
155
156	set_bit(FF_RUMBLE, dev->ffbit);
157
158	holtekff->field = report->field[0];
159
160	/* initialize the same way as win driver does */
161	holtekff_send(holtekff, hid, stop_all4);
162	holtekff_send(holtekff, hid, stop_all6);
163
164	error = input_ff_create_memless(dev, holtekff, holtekff_play);
165	if (error) {
166		kfree(holtekff);
167		return error;
168	}
169
170	hid_info(hid, "Force feedback for Holtek On Line Grip based devices by Anssi Hannula <anssi.hannula@iki.fi>\n");
171
172	return 0;
173}
174#else
175static inline int holtekff_init(struct hid_device *hid)
176{
177	return 0;
178}
179#endif
180
181static int holtek_probe(struct hid_device *hdev, const struct hid_device_id *id)
182{
183	int ret;
184
185	ret = hid_parse(hdev);
186	if (ret) {
187		hid_err(hdev, "parse failed\n");
188		goto err;
189	}
190
191	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
192	if (ret) {
193		hid_err(hdev, "hw start failed\n");
194		goto err;
195	}
196
197	holtekff_init(hdev);
198
199	return 0;
200err:
201	return ret;
202}
203
204static const struct hid_device_id holtek_devices[] = {
205	{ HID_USB_DEVICE(USB_VENDOR_ID_HOLTEK, USB_DEVICE_ID_HOLTEK_ON_LINE_GRIP) },
206	{ }
207};
208MODULE_DEVICE_TABLE(hid, holtek_devices);
209
210static struct hid_driver holtek_driver = {
211	.name = "holtek",
212	.id_table = holtek_devices,
213	.probe = holtek_probe,
214};
215module_hid_driver(holtek_driver);
216
217MODULE_LICENSE("GPL");
218MODULE_AUTHOR("Anssi Hannula <anssi.hannula@iki.fi>");
219MODULE_DESCRIPTION("Force feedback support for Holtek On Line Grip based devices");
220