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 #include <linux/module.h>
  28
  29 #include "hid-ids.h"
  30 #include "usbhid/usbhid.h"
  31
  32 struct emsff_device {
  33         struct hid_report *report;
  34 };
  35
  36 static int emsff_play(struct input_dev *dev, void *data,
  37                          struct ff_effect *effect)
  38 {
  39         struct hid_device *hid = input_get_drvdata(dev);
  40         struct emsff_device *emsff = data;
  41         int weak, strong;
  42
  43         weak = effect->u.rumble.weak_magnitude;
  44         strong = effect->u.rumble.strong_magnitude;
  45
  46         dbg_hid("called with 0x%04x 0x%04x\n", strong, weak);
  47
  48         weak = weak * 0xff / 0xffff;
  49         strong = strong * 0xff / 0xffff;
  50
  51         emsff->report->field[0]->value[1] = weak;
  52         emsff->report->field[0]->value[2] = strong;
  53
  54         dbg_hid("running with 0x%02x 0x%02x\n", strong, weak);
  55         usbhid_submit_report(hid, emsff->report, USB_DIR_OUT);
  56
  57         return 0;
  58 }
  59
  60 static int emsff_init(struct hid_device *hid)
  61 {
  62         struct emsff_device *emsff;
  63         struct hid_report *report;
  64         struct hid_input *hidinput = list_first_entry(&hid->inputs,
  65                                                 struct hid_input, list);
  66         struct list_head *report_list =
  67                         &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  68         struct input_dev *dev = hidinput->input;
  69         int error;
  70
  71         if (list_empty(report_list)) {
  72                 hid_err(hid, "no output reports found\n");
  73                 return -ENODEV;
  74         }
  75
  76         report = list_first_entry(report_list, struct hid_report, list);
  77         if (report->maxfield < 1) {
  78                 hid_err(hid, "no fields in the report\n");
  79                 return -ENODEV;
  80         }
  81
  82         if (report->field[0]->report_count < 7) {
  83                 hid_err(hid, "not enough values in the field\n");
  84                 return -ENODEV;
  85         }
  86
  87         emsff = kzalloc(sizeof(struct emsff_device), GFP_KERNEL);
  88         if (!emsff)
  89                 return -ENOMEM;
  90
  91         set_bit(FF_RUMBLE, dev->ffbit);
  92
  93         error = input_ff_create_memless(dev, emsff, emsff_play);
  94         if (error) {
  95                 kfree(emsff);
  96                 return error;
  97         }
  98
  99         emsff->report = report;
 100         emsff->report->field[0]->value[0] = 0x01;
 101         emsff->report->field[0]->value[1] = 0x00;
 102         emsff->report->field[0]->value[2] = 0x00;
 103         emsff->report->field[0]->value[3] = 0x00;
 104         emsff->report->field[0]->value[4] = 0x00;
 105         emsff->report->field[0]->value[5] = 0x00;
 106         emsff->report->field[0]->value[6] = 0x00;
 107         usbhid_submit_report(hid, emsff->report, USB_DIR_OUT);
 108
 109         hid_info(hid, "force feedback for EMS based devices by Ignaz Forster <ignaz.forster@gmx.de>\n");
 110
 111         return 0;
 112 }
 113
 114 static int ems_probe(struct hid_device *hdev, const struct hid_device_id *id)
 115 {
 116         int ret;
 117
 118         ret = hid_parse(hdev);
 119         if (ret) {
 120                 hid_err(hdev, "parse failed\n");
 121                 goto err;
 122         }
 123
 124         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
 125         if (ret) {
 126                 hid_err(hdev, "hw start failed\n");
 127                 goto err;
 128         }
 129
 130         ret = emsff_init(hdev);
 131         if (ret) {
 132                 dev_err(&hdev->dev, "force feedback init failed\n");
 133                 hid_hw_stop(hdev);
 134                 goto err;
 135         }
 136
 137         return 0;
 138 err:
 139         return ret;
 140 }
 141
 142 static const struct hid_device_id ems_devices[] = {
 143         { HID_USB_DEVICE(USB_VENDOR_ID_EMS, USB_DEVICE_ID_EMS_TRIO_LINKER_PLUS_II) },
 144         { }
 145 };
 146 MODULE_DEVICE_TABLE(hid, ems_devices);
 147
 148 static struct hid_driver ems_driver = {
 149         .name = "hkems",
 150         .id_table = ems_devices,
 151         .probe = ems_probe,
 152 };
 153
 154 static int ems_init(void)
 155 {
 156         return hid_register_driver(&ems_driver);
 157 }
 158
 159 static void ems_exit(void)
 160 {
 161         hid_unregister_driver(&ems_driver);
 162 }
 163
 164 module_init(ems_init);
 165 module_exit(ems_exit);
 166 MODULE_LICENSE("GPL");
 167