// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (c) 1999-2001 Vojtech Pavlik
 */

/*
 * Logitech WingMan Warrior joystick driver for Linux
 */

/*
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/serio.h>

#define DRIVER_DESC     "Logitech WingMan Warrior joystick driver"

MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

/*
 * Constants.
 */

#define WARRIOR_MAX_LENGTH      16
static char warrior_lengths[] = { 0, 4, 12, 3, 4, 4, 0, 0 };

/*
 * Per-Warrior data.
 */

struct warrior {
        struct input_dev *dev;
        int idx, len;
        unsigned char data[WARRIOR_MAX_LENGTH];
        char phys[32];
};

/*
 * warrior_process_packet() decodes packets the driver receives from the
 * Warrior. It updates the data accordingly.
 */

static void warrior_process_packet(struct warrior *warrior)
{
        struct input_dev *dev = warrior->dev;
        unsigned char *data = warrior->data;

        if (!warrior->idx) return;

        switch ((data[0] >> 4) & 7) {
                case 1:                                 /* Button data */
                        input_report_key(dev, BTN_TRIGGER,  data[3]       & 1);
                        input_report_key(dev, BTN_THUMB,   (data[3] >> 1) & 1);
                        input_report_key(dev, BTN_TOP,     (data[3] >> 2) & 1);
                        input_report_key(dev, BTN_TOP2,    (data[3] >> 3) & 1);
                        break;
                case 3:                                 /* XY-axis info->data */
                        input_report_abs(dev, ABS_X, ((data[0] & 8) << 5) - (data[2] | ((data[0] & 4) << 5)));
                        input_report_abs(dev, ABS_Y, (data[1] | ((data[0] & 1) << 7)) - ((data[0] & 2) << 7));
                        break;
                case 5:                                 /* Throttle, spinner, hat info->data */
                        input_report_abs(dev, ABS_THROTTLE, (data[1] | ((data[0] & 1) << 7)) - ((data[0] & 2) << 7));
                        input_report_abs(dev, ABS_HAT0X, (data[3] & 2 ? 1 : 0) - (data[3] & 1 ? 1 : 0));
                        input_report_abs(dev, ABS_HAT0Y, (data[3] & 8 ? 1 : 0) - (data[3] & 4 ? 1 : 0));
                        input_report_rel(dev, REL_DIAL,  (data[2] | ((data[0] & 4) << 5)) - ((data[0] & 8) << 5));
                        break;
        }
        input_sync(dev);
}

/*
 * warrior_interrupt() is called by the low level driver when characters
 * are ready for us. We then buffer them for further processing, or call the
 * packet processing routine.
 */

static irqreturn_t warrior_interrupt(struct serio *serio,
                unsigned char data, unsigned int flags)
{
        struct warrior *warrior = serio_get_drvdata(serio);

        if (data & 0x80) {
                if (warrior->idx) warrior_process_packet(warrior);
                warrior->idx = 0;
                warrior->len = warrior_lengths[(data >> 4) & 7];
        }

        if (warrior->idx < warrior->len)
                warrior->data[warrior->idx++] = data;

        if (warrior->idx == warrior->len) {
                if (warrior->idx) warrior_process_packet(warrior);
                warrior->idx = 0;
                warrior->len = 0;
        }
        return IRQ_HANDLED;
}

/*
 * warrior_disconnect() is the opposite of warrior_connect()
 */

static void warrior_disconnect(struct serio *serio)
{
        struct warrior *warrior = serio_get_drvdata(serio);

        serio_close(serio);
        serio_set_drvdata(serio, NULL);
        input_unregister_device(warrior->dev);
        kfree(warrior);
}

/*
 * warrior_connect() is the routine that is called when someone adds a
 * new serio device. It looks for the Warrior, and if found, registers
 * it as an input device.
 */

static int warrior_connect(struct serio *serio, struct serio_driver *drv)
{
        struct warrior *warrior;
        struct input_dev *input_dev;
        int err = -ENOMEM;

        warrior = kzalloc(sizeof(struct warrior), GFP_KERNEL);
        input_dev = input_allocate_device();
        if (!warrior || !input_dev)
                goto fail1;

        warrior->dev = input_dev;
        snprintf(warrior->phys, sizeof(warrior->phys), "%s/input0", serio->phys);

        input_dev->name = "Logitech WingMan Warrior";
        input_dev->phys = warrior->phys;
        input_dev->id.bustype = BUS_RS232;
        input_dev->id.vendor = SERIO_WARRIOR;
        input_dev->id.product = 0x0001;
        input_dev->id.version = 0x0100;
        input_dev->dev.parent = &serio->dev;

        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) |
                BIT_MASK(EV_ABS);
        input_dev->keybit[BIT_WORD(BTN_TRIGGER)] = BIT_MASK(BTN_TRIGGER) |
                BIT_MASK(BTN_THUMB) | BIT_MASK(BTN_TOP) | BIT_MASK(BTN_TOP2);
        input_dev->relbit[0] = BIT_MASK(REL_DIAL);
        input_set_abs_params(input_dev, ABS_X, -64, 64, 0, 8);
        input_set_abs_params(input_dev, ABS_Y, -64, 64, 0, 8);
        input_set_abs_params(input_dev, ABS_THROTTLE, -112, 112, 0, 0);
        input_set_abs_params(input_dev, ABS_HAT0X, -1, 1, 0, 0);
        input_set_abs_params(input_dev, ABS_HAT0Y, -1, 1, 0, 0);

        serio_set_drvdata(serio, warrior);

        err = serio_open(serio, drv);
        if (err)
                goto fail2;

        err = input_register_device(warrior->dev);
        if (err)
                goto fail3;

        return 0;

 fail3: serio_close(serio);
 fail2: serio_set_drvdata(serio, NULL);
 fail1: input_free_device(input_dev);
        kfree(warrior);
        return err;
}

/*
 * The serio driver structure.
 */

static const struct serio_device_id warrior_serio_ids[] = {
        {
                .type   = SERIO_RS232,
                .proto  = SERIO_WARRIOR,
                .id     = SERIO_ANY,
                .extra  = SERIO_ANY,
        },
        { 0 }
};

MODULE_DEVICE_TABLE(serio, warrior_serio_ids);

static struct serio_driver warrior_drv = {
        .driver         = {
                .name   = "warrior",
        },
        .description    = DRIVER_DESC,
        .id_table       = warrior_serio_ids,
        .interrupt      = warrior_interrupt,
        .connect        = warrior_connect,
        .disconnect     = warrior_disconnect,
};

module_serio_driver(warrior_drv);