drivers/hid/hid-lg2ff.c

   1 /*
   2  *  Force feedback support for Logitech Rumblepad 2
   3  *
   4  *  Copyright (c) 2008 Anssi Hannula <anssi.hannula@gmail.com>
   5  */
   6
   7 /*
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  21  */
  22
  23
  24 #include <linux/input.h>
  25 #include <linux/slab.h>
  26 #include <linux/usb.h>
  27 #include <linux/hid.h>
  28
  29 #include "usbhid/usbhid.h"
  30 #include "hid-lg.h"
  31
  32 struct lg2ff_device {
  33         struct hid_report *report;
  34 };
  35
  36 static int play_effect(struct input_dev *dev, void *data,
  37                          struct ff_effect *effect)
  38 {
  39         struct hid_device *hid = input_get_drvdata(dev);
  40         struct lg2ff_device *lg2ff = data;
  41         int weak, strong;
  42
  43         strong = effect->u.rumble.strong_magnitude;
  44         weak = effect->u.rumble.weak_magnitude;
  45
  46         if (weak || strong) {
  47                 weak = weak * 0xff / 0xffff;
  48                 strong = strong * 0xff / 0xffff;
  49
  50                 lg2ff->report->field[0]->value[0] = 0x51;
  51                 lg2ff->report->field[0]->value[2] = weak;
  52                 lg2ff->report->field[0]->value[4] = strong;
  53         } else {
  54                 lg2ff->report->field[0]->value[0] = 0xf3;
  55                 lg2ff->report->field[0]->value[2] = 0x00;
  56                 lg2ff->report->field[0]->value[4] = 0x00;
  57         }
  58
  59         usbhid_submit_report(hid, lg2ff->report, USB_DIR_OUT);
  60         return 0;
  61 }
  62
  63 int lg2ff_init(struct hid_device *hid)
  64 {
  65         struct lg2ff_device *lg2ff;
  66         struct hid_report *report;
  67         struct hid_input *hidinput = list_entry(hid->inputs.next,
  68                                                 struct hid_input, list);
  69         struct list_head *report_list =
  70                         &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  71         struct input_dev *dev = hidinput->input;
  72         int error;
  73
  74         if (list_empty(report_list)) {
  75                 dev_err(&hid->dev, "no output report found\n");
  76                 return -ENODEV;
  77         }
  78
  79         report = list_entry(report_list->next, struct hid_report, list);
  80
  81         if (report->maxfield < 1) {
  82                 dev_err(&hid->dev, "output report is empty\n");
  83                 return -ENODEV;
  84         }
  85         if (report->field[0]->report_count < 7) {
  86                 dev_err(&hid->dev, "not enough values in the field\n");
  87                 return -ENODEV;
  88         }
  89
  90         lg2ff = kmalloc(sizeof(struct lg2ff_device), GFP_KERNEL);
  91         if (!lg2ff)
  92                 return -ENOMEM;
  93
  94         set_bit(FF_RUMBLE, dev->ffbit);
  95
  96         error = input_ff_create_memless(dev, lg2ff, play_effect);
  97         if (error) {
  98                 kfree(lg2ff);
  99                 return error;
 100         }
 101
 102         lg2ff->report = report;
 103         report->field[0]->value[0] = 0xf3;
 104         report->field[0]->value[1] = 0x00;
 105         report->field[0]->value[2] = 0x00;
 106         report->field[0]->value[3] = 0x00;
 107         report->field[0]->value[4] = 0x00;
 108         report->field[0]->value[5] = 0x00;
 109         report->field[0]->value[6] = 0x00;
 110
 111         usbhid_submit_report(hid, report, USB_DIR_OUT);
 112
 113         dev_info(&hid->dev, "Force feedback for Logitech Rumblepad 2 by "
 114                "Anssi Hannula <anssi.hannula@gmail.com>\n");
 115
 116         return 0;
 117 }