/*
 * Force feedback support for ACRUX game controllers
 *
 * From what I have gathered, these devices are mass produced in China
 * by several vendors. They often share the same design as the original
 * Xbox 360 controller.
 *
 * 1a34:0802 "ACRUX USB GAMEPAD 8116"
 *  - tested with an EXEQ EQ-PCU-02090 game controller.
 *
 * Copyright (c) 2010 Sergei Kolzun <x0r@dv-life.ru>
 */

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

#include "hid-ids.h"

#ifdef CONFIG_HID_ACRUX_FF

struct axff_device {
        struct hid_report *report;
};

static int axff_play(struct input_dev *dev, void *data, struct ff_effect *effect)
{
        struct hid_device *hid = input_get_drvdata(dev);
        struct axff_device *axff = data;
        struct hid_report *report = axff->report;
        int field_count = 0;
        int left, right;
        int i, j;

        left = effect->u.rumble.strong_magnitude;
        right = effect->u.rumble.weak_magnitude;

        dbg_hid("called with 0x%04x 0x%04x", left, right);

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

        for (i = 0; i < report->maxfield; i++) {
                for (j = 0; j < report->field[i]->report_count; j++) {
                        report->field[i]->value[j] =
                                field_count % 2 ? right : left;
                        field_count++;
                }
        }

        dbg_hid("running with 0x%02x 0x%02x", left, right);
        hid_hw_request(hid, axff->report, HID_REQ_SET_REPORT);

        return 0;
}

static int axff_init(struct hid_device *hid)
{
        struct axff_device *axff;
        struct hid_report *report;
        struct hid_input *hidinput = list_first_entry(&hid->inputs, struct hid_input, list);
        struct list_head *report_list =&hid->report_enum[HID_OUTPUT_REPORT].report_list;
        struct input_dev *dev = hidinput->input;
        int field_count = 0;
        int i, j;
        int error;

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

        report = list_first_entry(report_list, struct hid_report, list);
        for (i = 0; i < report->maxfield; i++) {
                for (j = 0; j < report->field[i]->report_count; j++) {
                        report->field[i]->value[j] = 0x00;
                        field_count++;
                }
        }

        if (field_count < 4 && hid->product != 0xf705) {
                hid_err(hid, "not enough fields in the report: %d\n",
                        field_count);
                return -ENODEV;
        }

        axff = kzalloc(sizeof(struct axff_device), GFP_KERNEL);
        if (!axff)
                return -ENOMEM;

        set_bit(FF_RUMBLE, dev->ffbit);

        error = input_ff_create_memless(dev, axff, axff_play);
        if (error)
                goto err_free_mem;

        axff->report = report;
        hid_hw_request(hid, axff->report, HID_REQ_SET_REPORT);

        hid_info(hid, "Force Feedback for ACRUX game controllers by Sergei Kolzun <x0r@dv-life.ru>\n");

        return 0;

err_free_mem:
        kfree(axff);
        return error;
}
#else
static inline int axff_init(struct hid_device *hid)
{
        return 0;
}
#endif

static int ax_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
        int error;

        dev_dbg(&hdev->dev, "ACRUX HID hardware probe...\n");

        error = hid_parse(hdev);
        if (error) {
                hid_err(hdev, "parse failed\n");
                return error;
        }

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

        error = axff_init(hdev);
        if (error) {
                /*
                 * Do not fail device initialization completely as device
                 * may still be partially operable, just warn.
                 */
                hid_warn(hdev,
                         "Failed to enable force feedback support, error: %d\n",
                         error);
        }

        /*
         * We need to start polling device right away, otherwise
         * it will go into a coma.
         */
        error = hid_hw_open(hdev);
        if (error) {
                dev_err(&hdev->dev, "hw open failed\n");
                hid_hw_stop(hdev);
                return error;
        }

        return 0;
}

static void ax_remove(struct hid_device *hdev)
{
        hid_hw_close(hdev);
        hid_hw_stop(hdev);
}

static const struct hid_device_id ax_devices[] = {
        { HID_USB_DEVICE(USB_VENDOR_ID_ACRUX, 0x0802), },
        { HID_USB_DEVICE(USB_VENDOR_ID_ACRUX, 0xf705), },
        { }
};
MODULE_DEVICE_TABLE(hid, ax_devices);

static struct hid_driver ax_driver = {
        .name           = "acrux",
        .id_table       = ax_devices,
        .probe          = ax_probe,
        .remove         = ax_remove,
};
module_hid_driver(ax_driver);

MODULE_AUTHOR("Sergei Kolzun");
MODULE_DESCRIPTION("Force feedback support for ACRUX game controllers");
MODULE_LICENSE("GPL");