LXR linux/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
  33struct lg4ff_device {
  34        struct hid_report *report;
  35};
  36
  37static const signed short ff4_wheel_ac[] = {
  38        FF_CONSTANT,
  39        FF_AUTOCENTER,
  40        -1
  41};
  42
  43static 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
  72static 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
  91int 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                hid_err(hid, "No output report found\n");
 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                hid_err(hid, "NULL output report\n");
 112                return -1;
 113        }
 114
 115        field = report->field[0];
 116        if (!field) {
 117                hid_err(hid, "NULL field\n");
 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        hid_info(hid, "Force feedback for Logitech Speed Force Wireless by Simon Wood <simon@mungewell.org>\n");
 133        return 0;
 134}
 135
 136