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;
  63         struct list_head *report_list =
  64                         &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  65         struct input_dev *dev;
  66         int error;
  67
  68         if (list_empty(&hid->inputs)) {
  69                 hid_err(hid, "no inputs found\n");
  70                 return -ENODEV;
  71         }
  72         hidinput = list_first_entry(&hid->inputs, struct hid_input, list);
  73         dev = hidinput->input;
  74
  75         if (list_empty(report_list)) {
  76                 hid_err(hid, "no output reports found\n");
  77                 return -ENODEV;
  78         }
  79
  80         report = list_first_entry(report_list, struct hid_report, list);
  81         if (report->maxfield < 1) {
  82                 hid_err(hid, "no fields in the report\n");
  83                 return -ENODEV;
  84         }
  85
  86         if (report->field[0]->report_count < 7) {
  87                 hid_err(hid, "not enough values in the field\n");
  88                 return -ENODEV;
  89         }
  90
  91         emsff = kzalloc(sizeof(struct emsff_device), GFP_KERNEL);
  92         if (!emsff)
  93                 return -ENOMEM;
  94
  95         set_bit(FF_RUMBLE, dev->ffbit);
  96
  97         error = input_ff_create_memless(dev, emsff, emsff_play);
  98         if (error) {
  99                 kfree(emsff);
 100                 return error;
 101         }
 102
 103         emsff->report = report;
 104         emsff->report->field[0]->value[0] = 0x01;
 105         emsff->report->field[0]->value[1] = 0x00;
 106         emsff->report->field[0]->value[2] = 0x00;
 107         emsff->report->field[0]->value[3] = 0x00;
 108         emsff->report->field[0]->value[4] = 0x00;
 109         emsff->report->field[0]->value[5] = 0x00;
 110         emsff->report->field[0]->value[6] = 0x00;
 111         hid_hw_request(hid, emsff->report, HID_REQ_SET_REPORT);
 112
 113         hid_info(hid, "force feedback for EMS based devices by Ignaz Forster <ignaz.forster@gmx.de>\n");
 114
 115         return 0;
 116 }
 117
 118 static int ems_probe(struct hid_device *hdev, const struct hid_device_id *id)
 119 {
 120         int ret;
 121
 122         ret = hid_parse(hdev);
 123         if (ret) {
 124                 hid_err(hdev, "parse failed\n");
 125                 goto err;
 126         }
 127
 128         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
 129         if (ret) {
 130                 hid_err(hdev, "hw start failed\n");
 131                 goto err;
 132         }
 133
 134         ret = emsff_init(hdev);
 135         if (ret) {
 136                 dev_err(&hdev->dev, "force feedback init failed\n");
 137                 hid_hw_stop(hdev);
 138                 goto err;
 139         }
 140
 141         return 0;
 142 err:
 143         return ret;
 144 }
 145
 146 static const struct hid_device_id ems_devices[] = {
 147         { HID_USB_DEVICE(USB_VENDOR_ID_EMS, USB_DEVICE_ID_EMS_TRIO_LINKER_PLUS_II) },
 148         { }
 149 };
 150 MODULE_DEVICE_TABLE(hid, ems_devices);
 151
 152 static struct hid_driver ems_driver = {
 153         .name = "hkems",
 154         .id_table = ems_devices,
 155         .probe = ems_probe,
 156 };
 157 module_hid_driver(ems_driver);
 158
 159 MODULE_LICENSE("GPL");
 160