drivers/hid/hid-lg4ff.c

   1 /*
   2  *  Force feedback support for Logitech Speed Force Wireless
   3  *
   4  *  http://wiibrew.org/wiki/Logitech_USB_steering_wheel
   5  *
   6  *  Copyright (c) 2010 Simon Wood <simon@mungewell.org>
   7  */
   8
   9 /*
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  */
  24
  25
  26 #include <linux/input.h>
  27 #include <linux/usb.h>
  28 #include <linux/hid.h>
  29
  30 #include "usbhid/usbhid.h"
  31 #include "hid-lg.h"
  32
  33 struct lg4ff_device {
  34         struct hid_report *report;
  35 };
  36
  37 static const signed short ff4_wheel_ac[] = {
  38         FF_CONSTANT,
  39         FF_AUTOCENTER,
  40         -1
  41 };
  42
  43 static int hid_lg4ff_play(struct input_dev *dev, void *data,
  44                          struct ff_effect *effect)
  45 {
  46         struct hid_device *hid = input_get_drvdata(dev);
  47         struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  48         struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
  49         int x;
  50
  51 #define CLAMP(x) if (x < 0) x = 0; if (x > 0xff) x = 0xff
  52
  53         switch (effect->type) {
  54         case FF_CONSTANT:
  55                 x = effect->u.ramp.start_level + 0x80;  /* 0x80 is no force */
  56                 CLAMP(x);
  57                 report->field[0]->value[0] = 0x11;      /* Slot 1 */
  58                 report->field[0]->value[1] = 0x10;
  59                 report->field[0]->value[2] = x;
  60                 report->field[0]->value[3] = 0x00;
  61                 report->field[0]->value[4] = 0x00;
  62                 report->field[0]->value[5] = 0x08;
  63                 report->field[0]->value[6] = 0x00;
  64                 dbg_hid("Autocenter, x=0x%02X\n", x);
  65
  66                 usbhid_submit_report(hid, report, USB_DIR_OUT);
  67                 break;
  68         }
  69         return 0;
  70 }
  71
  72 static void hid_lg4ff_set_autocenter(struct input_dev *dev, u16 magnitude)
  73 {
  74         struct hid_device *hid = input_get_drvdata(dev);
  75         struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  76         struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
  77         __s32 *value = report->field[0]->value;
  78
  79         *value++ = 0xfe;
  80         *value++ = 0x0d;
  81         *value++ = 0x07;
  82         *value++ = 0x07;
  83         *value++ = (magnitude >> 8) & 0xff;
  84         *value++ = 0x00;
  85         *value = 0x00;
  86
  87         usbhid_submit_report(hid, report, USB_DIR_OUT);
  88 }
  89
  90
  91 int lg4ff_init(struct hid_device *hid)
  92 {
  93         struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
  94         struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
  95         struct input_dev *dev = hidinput->input;
  96         struct hid_report *report;
  97         struct hid_field *field;
  98         const signed short *ff_bits = ff4_wheel_ac;
  99         int error;
 100         int i;
 101
 102         /* Find the report to use */
 103         if (list_empty(report_list)) {
 104                 err_hid("No output report found");
 105                 return -1;
 106         }
 107
 108         /* Check that the report looks ok */
 109         report = list_entry(report_list->next, struct hid_report, list);
 110         if (!report) {
 111                 err_hid("NULL output report");
 112                 return -1;
 113         }
 114
 115         field = report->field[0];
 116         if (!field) {
 117                 err_hid("NULL field");
 118                 return -1;
 119         }
 120
 121         for (i = 0; ff_bits[i] >= 0; i++)
 122                 set_bit(ff_bits[i], dev->ffbit);
 123
 124         error = input_ff_create_memless(dev, NULL, hid_lg4ff_play);
 125
 126         if (error)
 127                 return error;
 128
 129         if (test_bit(FF_AUTOCENTER, dev->ffbit))
 130                 dev->ff->set_autocenter = hid_lg4ff_set_autocenter;
 131
 132         dev_info(&hid->dev, "Force feedback for Logitech Speed Force Wireless by "
 133                         "Simon Wood <simon@mungewell.org>\n");
 134         return 0;
 135 }
 136