/*
 *  Force feedback support for PantherLord/GreenAsia based devices
 *
 *  The devices are distributed under various names and the same USB device ID
 *  can be used in both adapters and actual game controllers.
 *
 *  0810:0001 "Twin USB Joystick"
 *   - tested with PantherLord USB/PS2 2in1 Adapter
 *   - contains two reports, one for each port (HID_QUIRK_MULTI_INPUT)
 *
 *  0e8f:0003 "GreenAsia Inc.    USB Joystick     "
 *   - tested with König Gaming gamepad
 *
 *  0e8f:0003 "GASIA USB Gamepad"
 *   - another version of the König gamepad
 *
 *  Copyright (c) 2007, 2009 Anssi Hannula <anssi.hannula@gmail.com>
 */

/*
 * 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
 */


/* #define DEBUG */

#define debug(format, arg...) pr_debug("hid-plff: " format "\n" , ## arg)

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

#include "hid-ids.h"

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

struct plff_device {
        struct hid_report *report;
        s32 *strong;
        s32 *weak;
};

static int hid_plff_play(struct input_dev *dev, void *data,
                         struct ff_effect *effect)
{
        struct hid_device *hid = input_get_drvdata(dev);
        struct plff_device *plff = data;
        int left, right;

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

        left = left * 0x7f / 0xffff;
        right = right * 0x7f / 0xffff;

        *plff->strong = left;
        *plff->weak = right;
        debug("running with 0x%02x 0x%02x", left, right);
        usbhid_submit_report(hid, plff->report, USB_DIR_OUT);

        return 0;
}

static int plff_init(struct hid_device *hid)
{
        struct plff_device *plff;
        struct hid_report *report;
        struct hid_input *hidinput;
        struct list_head *report_list =
                        &hid->report_enum[HID_OUTPUT_REPORT].report_list;
        struct list_head *report_ptr = report_list;
        struct input_dev *dev;
        int error;
        s32 *strong;
        s32 *weak;

        /* The device contains one output report per physical device, all
           containing 1 field, which contains 4 ff00.0002 usages and 4 16bit
           absolute values.

           The input reports also contain a field which contains
           8 ff00.0001 usages and 8 boolean values. Their meaning is
           currently unknown.
           
           A version of the 0e8f:0003 exists that has all the values in
           separate fields and misses the extra input field, thus resembling
           Zeroplus (hid-zpff) devices.
        */

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

        list_for_each_entry(hidinput, &hid->inputs, list) {

                report_ptr = report_ptr->next;

                if (report_ptr == report_list) {
                        hid_err(hid, "required output report is missing\n");
                        return -ENODEV;
                }

                report = list_entry(report_ptr, struct hid_report, list);
                if (report->maxfield < 1) {
                        hid_err(hid, "no fields in the report\n");
                        return -ENODEV;
                }

                if (report->field[0]->report_count >= 4) {
                        report->field[0]->value[0] = 0x00;
                        report->field[0]->value[1] = 0x00;
                        strong = &report->field[0]->value[2];
                        weak = &report->field[0]->value[3];
                        debug("detected single-field device");
                } else if (report->maxfield >= 4 && report->field[0]->maxusage == 1 &&
                                report->field[0]->usage[0].hid == (HID_UP_LED | 0x43)) {
                        report->field[0]->value[0] = 0x00;
                        report->field[1]->value[0] = 0x00;
                        strong = &report->field[2]->value[0];
                        weak = &report->field[3]->value[0];
                        debug("detected 4-field device");
                } else {
                        hid_err(hid, "not enough fields or values\n");
                        return -ENODEV;
                }

                plff = kzalloc(sizeof(struct plff_device), GFP_KERNEL);
                if (!plff)
                        return -ENOMEM;

                dev = hidinput->input;

                set_bit(FF_RUMBLE, dev->ffbit);

                error = input_ff_create_memless(dev, plff, hid_plff_play);
                if (error) {
                        kfree(plff);
                        return error;
                }

                plff->report = report;
                plff->strong = strong;
                plff->weak = weak;

                *strong = 0x00;
                *weak = 0x00;
                usbhid_submit_report(hid, plff->report, USB_DIR_OUT);
        }

        hid_info(hid, "Force feedback for PantherLord/GreenAsia devices by Anssi Hannula <anssi.hannula@gmail.com>\n");

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

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

        if (id->driver_data)
                hdev->quirks |= HID_QUIRK_MULTI_INPUT;

        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;
        }

        plff_init(hdev);

        return 0;
err:
        return ret;
}

static const struct hid_device_id pl_devices[] = {
        { HID_USB_DEVICE(USB_VENDOR_ID_GAMERON, USB_DEVICE_ID_GAMERON_DUAL_PSX_ADAPTOR),
                .driver_data = 1 }, /* Twin USB Joystick */
        { HID_USB_DEVICE(USB_VENDOR_ID_GAMERON, USB_DEVICE_ID_GAMERON_DUAL_PCS_ADAPTOR),
                .driver_data = 1 }, /* Twin USB Joystick */
        { HID_USB_DEVICE(USB_VENDOR_ID_GREENASIA, 0x0003), },
        { }
};
MODULE_DEVICE_TABLE(hid, pl_devices);

static struct hid_driver pl_driver = {
        .name = "pantherlord",
        .id_table = pl_devices,
        .probe = pl_probe,
};

static int __init pl_init(void)
{
        return hid_register_driver(&pl_driver);
}

static void __exit pl_exit(void)
{
        hid_unregister_driver(&pl_driver);
}

module_init(pl_init);
module_exit(pl_exit);
MODULE_LICENSE("GPL");