hid-google-stadiaff.c

  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
 17struct 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
 27static 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
 42static 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
 60static 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
104static 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
130static 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
143static 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};
148MODULE_DEVICE_TABLE(hid, stadia_devices);
149
150static struct hid_driver stadia_driver = {
151	.name = "stadia",
152	.id_table = stadia_devices,
153	.probe = stadia_probe,
154	.remove = stadia_remove,
155};
156module_hid_driver(stadia_driver);
157
158MODULE_DESCRIPTION("Google Stadia controller rumble support.");
159MODULE_LICENSE("GPL");