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

   1/*
   2 *  Force feedback support for EMS Trio Linker Plus II
   3 *
   4 *  Copyright (c) 2010 Ignaz Forster <ignaz.forster@gmx.de>
   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/hid.h>
  25#include <linux/input.h>
  26#include <linux/usb.h>
  27
  28#include "hid-ids.h"
  29#include "usbhid/usbhid.h"
  30
  31struct emsff_device {
  32        struct hid_report *report;
  33};
  34
  35static int emsff_play(struct input_dev *dev, void *data,
  36                         struct ff_effect *effect)
  37{
  38        struct hid_device *hid = input_get_drvdata(dev);
  39        struct emsff_device *emsff = data;
  40        int weak, strong;
  41
  42        weak = effect->u.rumble.weak_magnitude;
  43        strong = effect->u.rumble.strong_magnitude;
  44
  45        dbg_hid("called with 0x%04x 0x%04x\n", strong, weak);
  46
  47        weak = weak * 0xff / 0xffff;
  48        strong = strong * 0xff / 0xffff;
  49
  50        emsff->report->field[0]->value[1] = weak;
  51        emsff->report->field[0]->value[2] = strong;
  52
  53        dbg_hid("running with 0x%02x 0x%02x\n", strong, weak);
  54        usbhid_submit_report(hid, emsff->report, USB_DIR_OUT);
  55
  56        return 0;
  57}
  58
  59static int emsff_init(struct hid_device *hid)
  60{
  61        struct emsff_device *emsff;
  62        struct hid_report *report;
  63        struct hid_input *hidinput = list_first_entry(&hid->inputs,
  64                                                struct hid_input, list);
  65        struct list_head *report_list =
  66                        &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  67        struct input_dev *dev = hidinput->input;
  68        int error;
  69
  70        if (list_empty(report_list)) {
  71                hid_err(hid, "no output reports found\n");
  72                return -ENODEV;
  73        }
  74
  75        report = list_first_entry(report_list, struct hid_report, list);
  76        if (report->maxfield < 1) {
  77                hid_err(hid, "no fields in the report\n");
  78                return -ENODEV;
  79        }
  80
  81        if (report->field[0]->report_count < 7) {
  82                hid_err(hid, "not enough values in the field\n");
  83                return -ENODEV;
  84        }
  85
  86        emsff = kzalloc(sizeof(struct emsff_device), GFP_KERNEL);
  87        if (!emsff)
  88                return -ENOMEM;
  89
  90        set_bit(FF_RUMBLE, dev->ffbit);
  91
  92        error = input_ff_create_memless(dev, emsff, emsff_play);
  93        if (error) {
  94                kfree(emsff);
  95                return error;
  96        }
  97
  98        emsff->report = report;
  99        emsff->report->field[0]->value[0] = 0x01;
 100        emsff->report->field[0]->value[1] = 0x00;
 101        emsff->report->field[0]->value[2] = 0x00;
 102        emsff->report->field[0]->value[3] = 0x00;
 103        emsff->report->field[0]->value[4] = 0x00;
 104        emsff->report->field[0]->value[5] = 0x00;
 105        emsff->report->field[0]->value[6] = 0x00;
 106        usbhid_submit_report(hid, emsff->report, USB_DIR_OUT);
 107
 108        hid_info(hid, "force feedback for EMS based devices by Ignaz Forster <ignaz.forster@gmx.de>\n");
 109
 110        return 0;
 111}
 112
 113static int ems_probe(struct hid_device *hdev, const struct hid_device_id *id)
 114{
 115        int ret;
 116
 117        ret = hid_parse(hdev);
 118        if (ret) {
 119                hid_err(hdev, "parse failed\n");
 120                goto err;
 121        }
 122
 123        ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
 124        if (ret) {
 125                hid_err(hdev, "hw start failed\n");
 126                goto err;
 127        }
 128
 129        emsff_init(hdev);
 130
 131        return 0;
 132err:
 133        return ret;
 134}
 135
 136static const struct hid_device_id ems_devices[] = {
 137        { HID_USB_DEVICE(USB_VENDOR_ID_EMS, 0x118) },
 138        { }
 139};
 140MODULE_DEVICE_TABLE(hid, ems_devices);
 141
 142static struct hid_driver ems_driver = {
 143        .name = "hkems",
 144        .id_table = ems_devices,
 145        .probe = ems_probe,
 146};
 147
 148static int ems_init(void)
 149{
 150        return hid_register_driver(&ems_driver);
 151}
 152
 153static void ems_exit(void)
 154{
 155        hid_unregister_driver(&ems_driver);
 156}
 157
 158module_init(ems_init);
 159module_exit(ems_exit);
 160MODULE_LICENSE("GPL");
 161
 162