drivers/hid/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
  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");