hid-lg2ff.c

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/*
 *  Force feedback support for Logitech RumblePad and Rumblepad 2
 *
 *  Copyright (c) 2008 Anssi Hannula <[email protected]>
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */


#include <linux/input.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/hid.h>

#include "usbhid/usbhid.h"
#include "hid-lg.h"

struct lg2ff_device {
    struct hid_report *report;
};

static int play_effect(struct input_dev *dev, void *data,
             struct ff_effect *effect)
{
    struct hid_device *hid = input_get_drvdata(dev);
    struct lg2ff_device *lg2ff = data;
    int weak, strong;

    strong = effect->u.rumble.strong_magnitude;
    weak = effect->u.rumble.weak_magnitude;

    if (weak || strong) {
        weak = weak * 0xff / 0xffff;
        strong = strong * 0xff / 0xffff;

        lg2ff->report->field[0]->value[0] = 0x51;
        lg2ff->report->field[0]->value[2] = weak;
        lg2ff->report->field[0]->value[4] = strong;
    } else {
        lg2ff->report->field[0]->value[0] = 0xf3;
        lg2ff->report->field[0]->value[2] = 0x00;
        lg2ff->report->field[0]->value[4] = 0x00;
    }

    usbhid_submit_report(hid, lg2ff->report, USB_DIR_OUT);
    return 0;
}

int lg2ff_init(struct hid_device *hid)
{
    struct lg2ff_device *lg2ff;
    struct hid_report *report;
    struct hid_input *hidinput = list_entry(hid->inputs.next,
                        struct hid_input, list);
    struct list_head *report_list =
            &hid->report_enum[HID_OUTPUT_REPORT].report_list;
    struct input_dev *dev = hidinput->input;
    int error;

    if (list_empty(report_list)) {
        hid_err(hid, "no output report found\n");
        return -ENODEV;
    }

    report = list_entry(report_list->next, struct hid_report, list);

    if (report->maxfield < 1) {
        hid_err(hid, "output report is empty\n");
        return -ENODEV;
    }
    if (report->field[0]->report_count < 7) {
        hid_err(hid, "not enough values in the field\n");
        return -ENODEV;
    }

    lg2ff = kmalloc(sizeof(struct lg2ff_device), GFP_KERNEL);
    if (!lg2ff)
        return -ENOMEM;

    set_bit(FF_RUMBLE, dev->ffbit);

    error = input_ff_create_memless(dev, lg2ff, play_effect);
    if (error) {
        kfree(lg2ff);
        return error;
    }

    lg2ff->report = report;
    report->field[0]->value[0] = 0xf3;
    report->field[0]->value[1] = 0x00;
    report->field[0]->value[2] = 0x00;
    report->field[0]->value[3] = 0x00;
    report->field[0]->value[4] = 0x00;
    report->field[0]->value[5] = 0x00;
    report->field[0]->value[6] = 0x00;

    usbhid_submit_report(hid, report, USB_DIR_OUT);

    hid_info(hid, "Force feedback for Logitech RumblePad/Rumblepad 2 by Anssi Hannula <[email protected]>\n");

    return 0;
}