xref: /openbmc/linux/drivers/hid/hid-holtekff.c (revision e65e175b)
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 
67 static const u8 start_effect_1[] = { 0x02, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00 };
68 static const u8 stop_all4[] =	   { 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
69 static const u8 stop_all6[] =	   { 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
70 
71 struct holtekff_device {
72 	struct hid_field *field;
73 };
74 
75 static 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 
90 static 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 
123 static 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
175 static inline int holtekff_init(struct hid_device *hid)
176 {
177 	return 0;
178 }
179 #endif
180 
181 static 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;
200 err:
201 	return ret;
202 }
203 
204 static const struct hid_device_id holtek_devices[] = {
205 	{ HID_USB_DEVICE(USB_VENDOR_ID_HOLTEK, USB_DEVICE_ID_HOLTEK_ON_LINE_GRIP) },
206 	{ }
207 };
208 MODULE_DEVICE_TABLE(hid, holtek_devices);
209 
210 static struct hid_driver holtek_driver = {
211 	.name = "holtek",
212 	.id_table = holtek_devices,
213 	.probe = holtek_probe,
214 };
215 module_hid_driver(holtek_driver);
216 
217 MODULE_LICENSE("GPL");
218 MODULE_AUTHOR("Anssi Hannula <anssi.hannula@iki.fi>");
219 MODULE_DESCRIPTION("Force feedback support for Holtek On Line Grip based devices");
220