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
  31 struct emsff_device {
  32         struct hid_report *report;
  33 };
  34
  35 static 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
  59 static 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
 113 static 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         ret = emsff_init(hdev);
 130         if (ret) {
 131                 dev_err(&hdev->dev, "force feedback init failed\n");
 132                 hid_hw_stop(hdev);
 133                 goto err;
 134         }
 135
 136         return 0;
 137 err:
 138         return ret;
 139 }
 140
 141 static const struct hid_device_id ems_devices[] = {
 142         { HID_USB_DEVICE(USB_VENDOR_ID_EMS, 0x118) },
 143         { }
 144 };
 145 MODULE_DEVICE_TABLE(hid, ems_devices);
 146
 147 static struct hid_driver ems_driver = {
 148         .name = "hkems",
 149         .id_table = ems_devices,
 150         .probe = ems_probe,
 151 };
 152
 153 static int ems_init(void)
 154 {
 155         return hid_register_driver(&ems_driver);
 156 }
 157
 158 static void ems_exit(void)
 159 {
 160         hid_unregister_driver(&ems_driver);
 161 }
 162
 163 module_init(ems_init);
 164 module_exit(ems_exit);
 165 MODULE_LICENSE("GPL");
 166