1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Stadia controller rumble support.
4 *
5 * Copyright 2023 Google LLC
6 */
7
8 #include <linux/hid.h>
9 #include <linux/input.h>
10 #include <linux/slab.h>
11 #include <linux/module.h>
12
13 #include "hid-ids.h"
14
15 #define STADIA_FF_REPORT_ID 5
16
17 struct stadiaff_device {
18 struct hid_device *hid;
19 struct hid_report *report;
20 spinlock_t lock;
21 bool removed;
22 uint16_t strong_magnitude;
23 uint16_t weak_magnitude;
24 struct work_struct work;
25 };
26
stadiaff_work(struct work_struct * work)27 static void stadiaff_work(struct work_struct *work)
28 {
29 struct stadiaff_device *stadiaff =
30 container_of(work, struct stadiaff_device, work);
31 struct hid_field *rumble_field = stadiaff->report->field[0];
32 unsigned long flags;
33
34 spin_lock_irqsave(&stadiaff->lock, flags);
35 rumble_field->value[0] = stadiaff->strong_magnitude;
36 rumble_field->value[1] = stadiaff->weak_magnitude;
37 spin_unlock_irqrestore(&stadiaff->lock, flags);
38
39 hid_hw_request(stadiaff->hid, stadiaff->report, HID_REQ_SET_REPORT);
40 }
41
stadiaff_play(struct input_dev * dev,void * data,struct ff_effect * effect)42 static int stadiaff_play(struct input_dev *dev, void *data,
43 struct ff_effect *effect)
44 {
45 struct hid_device *hid = input_get_drvdata(dev);
46 struct stadiaff_device *stadiaff = hid_get_drvdata(hid);
47 unsigned long flags;
48
49 spin_lock_irqsave(&stadiaff->lock, flags);
50 if (!stadiaff->removed) {
51 stadiaff->strong_magnitude = effect->u.rumble.strong_magnitude;
52 stadiaff->weak_magnitude = effect->u.rumble.weak_magnitude;
53 schedule_work(&stadiaff->work);
54 }
55 spin_unlock_irqrestore(&stadiaff->lock, flags);
56
57 return 0;
58 }
59
stadiaff_init(struct hid_device * hid)60 static int stadiaff_init(struct hid_device *hid)
61 {
62 struct stadiaff_device *stadiaff;
63 struct hid_report *report;
64 struct hid_input *hidinput;
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_entry(hid->inputs.next, struct hid_input, list);
73 dev = hidinput->input;
74
75 report = hid_validate_values(hid, HID_OUTPUT_REPORT,
76 STADIA_FF_REPORT_ID, 0, 2);
77 if (!report)
78 return -ENODEV;
79
80 stadiaff = devm_kzalloc(&hid->dev, sizeof(struct stadiaff_device),
81 GFP_KERNEL);
82 if (!stadiaff)
83 return -ENOMEM;
84
85 hid_set_drvdata(hid, stadiaff);
86
87 input_set_capability(dev, EV_FF, FF_RUMBLE);
88
89 error = input_ff_create_memless(dev, NULL, stadiaff_play);
90 if (error)
91 return error;
92
93 stadiaff->removed = false;
94 stadiaff->hid = hid;
95 stadiaff->report = report;
96 INIT_WORK(&stadiaff->work, stadiaff_work);
97 spin_lock_init(&stadiaff->lock);
98
99 hid_info(hid, "Force Feedback for Google Stadia controller\n");
100
101 return 0;
102 }
103
stadia_probe(struct hid_device * hdev,const struct hid_device_id * id)104 static int stadia_probe(struct hid_device *hdev, const struct hid_device_id *id)
105 {
106 int ret;
107
108 ret = hid_parse(hdev);
109 if (ret) {
110 hid_err(hdev, "parse failed\n");
111 return ret;
112 }
113
114 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
115 if (ret) {
116 hid_err(hdev, "hw start failed\n");
117 return ret;
118 }
119
120 ret = stadiaff_init(hdev);
121 if (ret) {
122 hid_err(hdev, "force feedback init failed\n");
123 hid_hw_stop(hdev);
124 return ret;
125 }
126
127 return 0;
128 }
129
stadia_remove(struct hid_device * hid)130 static void stadia_remove(struct hid_device *hid)
131 {
132 struct stadiaff_device *stadiaff = hid_get_drvdata(hid);
133 unsigned long flags;
134
135 spin_lock_irqsave(&stadiaff->lock, flags);
136 stadiaff->removed = true;
137 spin_unlock_irqrestore(&stadiaff->lock, flags);
138
139 cancel_work_sync(&stadiaff->work);
140 hid_hw_stop(hid);
141 }
142
143 static const struct hid_device_id stadia_devices[] = {
144 { HID_USB_DEVICE(USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STADIA) },
145 { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STADIA) },
146 { }
147 };
148 MODULE_DEVICE_TABLE(hid, stadia_devices);
149
150 static struct hid_driver stadia_driver = {
151 .name = "stadia",
152 .id_table = stadia_devices,
153 .probe = stadia_probe,
154 .remove = stadia_remove,
155 };
156 module_hid_driver(stadia_driver);
157
158 MODULE_LICENSE("GPL");
159