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