LXR linux/drivers/hid/hid-lg2ff.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  Force feedback support for Logitech RumblePad and Rumblepad 2
   4 *
   5 *  Copyright (c) 2008 Anssi Hannula <anssi.hannula@gmail.com>
   6 */
   7
   8/*
   9 */
  10
  11
  12#include <linux/input.h>
  13#include <linux/slab.h>
  14#include <linux/hid.h>
  15
  16#include "hid-lg.h"
  17
  18struct lg2ff_device {
  19        struct hid_report *report;
  20};
  21
  22static int play_effect(struct input_dev *dev, void *data,
  23                         struct ff_effect *effect)
  24{
  25        struct hid_device *hid = input_get_drvdata(dev);
  26        struct lg2ff_device *lg2ff = data;
  27        int weak, strong;
  28
  29        strong = effect->u.rumble.strong_magnitude;
  30        weak = effect->u.rumble.weak_magnitude;
  31
  32        if (weak || strong) {
  33                weak = weak * 0xff / 0xffff;
  34                strong = strong * 0xff / 0xffff;
  35
  36                lg2ff->report->field[0]->value[0] = 0x51;
  37                lg2ff->report->field[0]->value[2] = weak;
  38                lg2ff->report->field[0]->value[4] = strong;
  39        } else {
  40                lg2ff->report->field[0]->value[0] = 0xf3;
  41                lg2ff->report->field[0]->value[2] = 0x00;
  42                lg2ff->report->field[0]->value[4] = 0x00;
  43        }
  44
  45        hid_hw_request(hid, lg2ff->report, HID_REQ_SET_REPORT);
  46        return 0;
  47}
  48
  49int lg2ff_init(struct hid_device *hid)
  50{
  51        struct lg2ff_device *lg2ff;
  52        struct hid_report *report;
  53        struct hid_input *hidinput;
  54        struct input_dev *dev;
  55        int error;
  56
  57        if (list_empty(&hid->inputs)) {
  58                hid_err(hid, "no inputs found\n");
  59                return -ENODEV;
  60        }
  61        hidinput = list_entry(hid->inputs.next, struct hid_input, list);
  62        dev = hidinput->input;
  63
  64        /* Check that the report looks ok */
  65        report = hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 7);
  66        if (!report)
  67                return -ENODEV;
  68
  69        lg2ff = kmalloc(sizeof(struct lg2ff_device), GFP_KERNEL);
  70        if (!lg2ff)
  71                return -ENOMEM;
  72
  73        set_bit(FF_RUMBLE, dev->ffbit);
  74
  75        error = input_ff_create_memless(dev, lg2ff, play_effect);
  76        if (error) {
  77                kfree(lg2ff);
  78                return error;
  79        }
  80
  81        lg2ff->report = report;
  82        report->field[0]->value[0] = 0xf3;
  83        report->field[0]->value[1] = 0x00;
  84        report->field[0]->value[2] = 0x00;
  85        report->field[0]->value[3] = 0x00;
  86        report->field[0]->value[4] = 0x00;
  87        report->field[0]->value[5] = 0x00;
  88        report->field[0]->value[6] = 0x00;
  89
  90        hid_hw_request(hid, report, HID_REQ_SET_REPORT);
  91
  92        hid_info(hid, "Force feedback for Logitech variant 2 rumble devices by Anssi Hannula <anssi.hannula@gmail.com>\n");
  93
  94        return 0;
  95}
  96