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 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 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 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 } 103 104 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 } 129 130 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