hid-holtekff.c

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/*
 *  Force feedback support for Holtek On Line Grip based gamepads
 *
 *  These include at least a Brazilian "Clone Joypad Super Power Fire"
 *  which uses vendor ID 0x1241 and identifies as "HOLTEK On Line Grip".
 *
 *  Copyright (c) 2011 Anssi Hannula <[email protected]>
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/hid.h>
#include <linux/input.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>

#include "hid-ids.h"

#ifdef CONFIG_HOLTEK_FF
#include "usbhid/usbhid.h"

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Anssi Hannula <[email protected]>");
MODULE_DESCRIPTION("Force feedback support for Holtek On Line Grip based devices");

/*
 * These commands and parameters are currently known:
 *
 * byte 0: command id:
 *  01  set effect parameters
 *  02  play specified effect
 *  03  stop specified effect
 *  04  stop all effects
 *  06  stop all effects
 *  (the difference between 04 and 06 isn't known; win driver
 *   sends 06,04 on application init, and 06 otherwise)
 * 
 * Commands 01 and 02 need to be sent as pairs, i.e. you need to send 01
 * before each 02.
 *
 * The rest of the bytes are parameters. Command 01 takes all of them, and
 * commands 02,03 take only the effect id.
 *
 * byte 1:
 *  bits 0-3: effect id:
 *      1: very strong rumble
 *      2: periodic rumble, short intervals
 *      3: very strong rumble
 *      4: periodic rumble, long intervals
 *      5: weak periodic rumble, long intervals
 *      6: weak periodic rumble, short intervals
 *      7: periodic rumble, short intervals
 *      8: strong periodic rumble, short intervals
 *      9: very strong rumble
 *      a: causes an error
 *      b: very strong periodic rumble, very short intervals
 *      c-f: nothing
 *  bit 6: right (weak) motor enabled
 *  bit 7: left (strong) motor enabled
 *
 * bytes 2-3:  time in milliseconds, big-endian
 * bytes 5-6:  unknown (win driver seems to use at least 10e0 with effect 1
 *             and 0014 with effect 6)
 * byte 7:
 *  bits 0-3: effect magnitude
 */

#define HOLTEKFF_MSG_LENGTH     7

static const u8 start_effect_1[] = { 0x02, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00 };
static const u8 stop_all4[] =      { 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
static const u8 stop_all6[] =      { 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

struct holtekff_device {
    struct hid_field *field;
};

static void holtekff_send(struct holtekff_device *holtekff,
              struct hid_device *hid,
              const u8 data[HOLTEKFF_MSG_LENGTH])
{
    int i;

    for (i = 0; i < HOLTEKFF_MSG_LENGTH; i++) {
        holtekff->field->value[i] = data[i];
    }

    dbg_hid("sending %*ph\n", 7, data);

    usbhid_submit_report(hid, holtekff->field->report, USB_DIR_OUT);
}

static int holtekff_play(struct input_dev *dev, void *data,
             struct ff_effect *effect)
{
    struct hid_device *hid = input_get_drvdata(dev);
    struct holtekff_device *holtekff = data;
    int left, right;
    /* effect type 1, length 65535 msec */
    u8 buf[HOLTEKFF_MSG_LENGTH] =
        { 0x01, 0x01, 0xff, 0xff, 0x10, 0xe0, 0x00 };

    left = effect->u.rumble.strong_magnitude;
    right = effect->u.rumble.weak_magnitude;
    dbg_hid("called with 0x%04x 0x%04x\n", left, right);

    if (!left && !right) {
        holtekff_send(holtekff, hid, stop_all6);
        return 0;
    }

    if (left)
        buf[1] |= 0x80;
    if (right)
        buf[1] |= 0x40;

    /* The device takes a single magnitude, so we just sum them up. */
    buf[6] = min(0xf, (left >> 12) + (right >> 12));

    holtekff_send(holtekff, hid, buf);
    holtekff_send(holtekff, hid, start_effect_1);

    return 0;
}

static int holtekff_init(struct hid_device *hid)
{
    struct holtekff_device *holtekff;
    struct hid_report *report;
    struct hid_input *hidinput = list_entry(hid->inputs.next,
                        struct hid_input, list);
    struct list_head *report_list =
            &hid->report_enum[HID_OUTPUT_REPORT].report_list;
    struct input_dev *dev = hidinput->input;
    int error;

    if (list_empty(report_list)) {
        hid_err(hid, "no output report found\n");
        return -ENODEV;
    }

    report = list_entry(report_list->next, struct hid_report, list);

    if (report->maxfield < 1 || report->field[0]->report_count != 7) {
        hid_err(hid, "unexpected output report layout\n");
        return -ENODEV;
    }

    holtekff = kzalloc(sizeof(*holtekff), GFP_KERNEL);
    if (!holtekff)
        return -ENOMEM;

    set_bit(FF_RUMBLE, dev->ffbit);

    holtekff->field = report->field[0];

    /* initialize the same way as win driver does */
    holtekff_send(holtekff, hid, stop_all4);
    holtekff_send(holtekff, hid, stop_all6);

    error = input_ff_create_memless(dev, holtekff, holtekff_play);
    if (error) {
        kfree(holtekff);
        return error;
    }

    hid_info(hid, "Force feedback for Holtek On Line Grip based devices by Anssi Hannula <[email protected]>\n");

    return 0;
}
#else
static inline int holtekff_init(struct hid_device *hid)
{
    return 0;
}
#endif

static int holtek_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
    int ret;

    ret = hid_parse(hdev);
    if (ret) {
        hid_err(hdev, "parse failed\n");
        goto err;
    }

    ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
    if (ret) {
        hid_err(hdev, "hw start failed\n");
        goto err;
    }

    holtekff_init(hdev);

    return 0;
err:
    return ret;
}

static const struct hid_device_id holtek_devices[] = {
    { HID_USB_DEVICE(USB_VENDOR_ID_HOLTEK, USB_DEVICE_ID_HOLTEK_ON_LINE_GRIP) },
    { }
};
MODULE_DEVICE_TABLE(hid, holtek_devices);

static struct hid_driver holtek_driver = {
    .name = "holtek",
    .id_table = holtek_devices,
    .probe = holtek_probe,
};

static int __init holtek_init(void)
{
    return hid_register_driver(&holtek_driver);
}

static void __exit holtek_exit(void)
{
    hid_unregister_driver(&holtek_driver);
}

module_init(holtek_init);
module_exit(holtek_exit);