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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Force feedback support for Logitech RumblePad and Rumblepad 24 *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