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 u32 magnitudes; 21 struct work_struct work; 22 }; 23 24 static void stadiaff_work(struct work_struct *work) 25 { 26 struct stadiaff_device *stadiaff = 27 container_of(work, struct stadiaff_device, work); 28 struct hid_field *rumble_field = stadiaff->report->field[0]; 29 u32 mags = READ_ONCE(stadiaff->magnitudes); 30 31 rumble_field->value[0] = mags & 0xffff; 32 rumble_field->value[1] = (mags >> 16) & 0xffff; 33 34 hid_hw_request(stadiaff->hid, stadiaff->report, HID_REQ_SET_REPORT); 35 } 36 37 static int stadiaff_play(struct input_dev *dev, void *data, 38 struct ff_effect *effect) 39 { 40 struct hid_device *hid = input_get_drvdata(dev); 41 struct stadiaff_device *stadiaff = hid_get_drvdata(hid); 42 u32 mags = (u32)effect->u.rumble.strong_magnitude | 43 ((u32)effect->u.rumble.weak_magnitude << 16); 44 45 WRITE_ONCE(stadiaff->magnitudes, mags); 46 schedule_work(&stadiaff->work); 47 48 return 0; 49 } 50 51 static int stadia_input_open(struct input_dev *dev) 52 { 53 struct hid_device *hid = input_get_drvdata(dev); 54 struct stadiaff_device *stadiaff = hid_get_drvdata(hid); 55 int error; 56 57 error = hid_hw_open(hid); 58 if (error) 59 return error; 60 61 enable_work(&stadiaff->work); 62 return 0; 63 } 64 65 static void stadia_input_close(struct input_dev *dev) 66 { 67 struct hid_device *hid = input_get_drvdata(dev); 68 struct stadiaff_device *stadiaff = hid_get_drvdata(hid); 69 70 WRITE_ONCE(stadiaff->magnitudes, 0); 71 stadiaff_work(&stadiaff->work); 72 disable_work_sync(&stadiaff->work); 73 74 hid_hw_close(hid); 75 } 76 77 static int stadia_input_configured(struct hid_device *hid, struct hid_input *hidinput) 78 { 79 struct stadiaff_device *stadiaff; 80 struct hid_report *report; 81 struct input_dev *dev = hidinput->input; 82 int error; 83 84 if (!list_is_first(&hidinput->list, &hid->inputs)) 85 return 0; 86 87 report = hid_validate_values(hid, HID_OUTPUT_REPORT, 88 STADIA_FF_REPORT_ID, 0, 2); 89 if (!report) 90 return -ENODEV; 91 92 stadiaff = devm_kzalloc(&hid->dev, sizeof(struct stadiaff_device), 93 GFP_KERNEL); 94 if (!stadiaff) 95 return -ENOMEM; 96 97 hid_set_drvdata(hid, stadiaff); 98 99 input_set_capability(dev, EV_FF, FF_RUMBLE); 100 101 error = input_ff_create_memless(dev, NULL, stadiaff_play); 102 if (error) 103 return error; 104 105 stadiaff->hid = hid; 106 stadiaff->report = report; 107 INIT_WORK(&stadiaff->work, stadiaff_work); 108 disable_work_sync(&stadiaff->work); 109 110 dev->open = stadia_input_open; 111 dev->close = stadia_input_close; 112 113 hid_info(hid, "Force Feedback for Google Stadia controller\n"); 114 115 return 0; 116 } 117 118 static const struct hid_device_id stadia_devices[] = { 119 { HID_USB_DEVICE(USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STADIA) }, 120 { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STADIA) }, 121 { } 122 }; 123 MODULE_DEVICE_TABLE(hid, stadia_devices); 124 125 static struct hid_driver stadia_driver = { 126 .name = "stadia", 127 .id_table = stadia_devices, 128 .input_configured = stadia_input_configured, 129 }; 130 module_hid_driver(stadia_driver); 131 132 MODULE_DESCRIPTION("Google Stadia controller rumble support."); 133 MODULE_LICENSE("GPL"); 134