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

/*
 * XT keyboard driver for Linux
 */

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

#define DRIVER_DESC     "XT keyboard driver"

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

#define XTKBD_EMUL0     0xe0
#define XTKBD_EMUL1     0xe1
#define XTKBD_KEY       0x7f
#define XTKBD_RELEASE   0x80

static unsigned char xtkbd_keycode[256] = {
          0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
         16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
         32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
         48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
         64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
         80, 81, 82, 83,  0,  0,  0, 87, 88,  0,  0,  0,  0,  0,  0,  0,
          0,  0,  0,  0,  0, 87, 88,  0,  0,  0,  0,110,111,103,108,105,
        106
};

struct xtkbd {
        unsigned char keycode[256];
        struct input_dev *dev;
        struct serio *serio;
        char phys[32];
};

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

        switch (data) {
                case XTKBD_EMUL0:
                case XTKBD_EMUL1:
                        break;
                default:

                        if (xtkbd->keycode[data & XTKBD_KEY]) {
                                input_report_key(xtkbd->dev, xtkbd->keycode[data & XTKBD_KEY], !(data & XTKBD_RELEASE));
                                input_sync(xtkbd->dev);
                        } else {
                                printk(KERN_WARNING "xtkbd.c: Unknown key (scancode %#x) %s.\n",
                                        data & XTKBD_KEY, data & XTKBD_RELEASE ? "released" : "pressed");
                        }
        }
        return IRQ_HANDLED;
}

static int xtkbd_connect(struct serio *serio, struct serio_driver *drv)
{
        struct xtkbd *xtkbd;
        struct input_dev *input_dev;
        int err = -ENOMEM;
        int i;

        xtkbd = kmalloc_obj(*xtkbd);
        input_dev = input_allocate_device();
        if (!xtkbd || !input_dev)
                goto fail1;

        xtkbd->serio = serio;
        xtkbd->dev = input_dev;
        snprintf(xtkbd->phys, sizeof(xtkbd->phys), "%s/input0", serio->phys);
        memcpy(xtkbd->keycode, xtkbd_keycode, sizeof(xtkbd->keycode));

        input_dev->name = "XT Keyboard";
        input_dev->phys = xtkbd->phys;
        input_dev->id.bustype = BUS_XTKBD;
        input_dev->id.vendor  = 0x0001;
        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_REP);
        input_dev->keycode = xtkbd->keycode;
        input_dev->keycodesize = sizeof(unsigned char);
        input_dev->keycodemax = ARRAY_SIZE(xtkbd_keycode);

        for (i = 0; i < 255; i++)
                set_bit(xtkbd->keycode[i], input_dev->keybit);
        clear_bit(0, input_dev->keybit);

        serio_set_drvdata(serio, xtkbd);

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

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

        return 0;

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

static void xtkbd_disconnect(struct serio *serio)
{
        struct xtkbd *xtkbd = serio_get_drvdata(serio);

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

static const struct serio_device_id xtkbd_serio_ids[] = {
        {
                .type   = SERIO_XT,
                .proto  = SERIO_ANY,
                .id     = SERIO_ANY,
                .extra  = SERIO_ANY,
        },
        { 0 }
};

MODULE_DEVICE_TABLE(serio, xtkbd_serio_ids);

static struct serio_driver xtkbd_drv = {
        .driver         = {
                .name   = "xtkbd",
        },
        .description    = DRIVER_DESC,
        .id_table       = xtkbd_serio_ids,
        .interrupt      = xtkbd_interrupt,
        .connect        = xtkbd_connect,
        .disconnect     = xtkbd_disconnect,
};

module_serio_driver(xtkbd_drv);