// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (c) 2000 Justin Cormack
 */

/*
 * Newton keyboard driver for Linux
 */

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

#define DRIVER_DESC     "Newton keyboard driver"

MODULE_AUTHOR("Justin Cormack <j.cormack@doc.ic.ac.uk>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

#define NKBD_KEY        0x7f
#define NKBD_PRESS      0x80

static unsigned char nkbd_keycode[128] = {
        KEY_A, KEY_S, KEY_D, KEY_F, KEY_H, KEY_G, KEY_Z, KEY_X,
        KEY_C, KEY_V, 0, KEY_B, KEY_Q, KEY_W, KEY_E, KEY_R,
        KEY_Y, KEY_T, KEY_1, KEY_2, KEY_3, KEY_4, KEY_6, KEY_5,
        KEY_EQUAL, KEY_9, KEY_7, KEY_MINUS, KEY_8, KEY_0, KEY_RIGHTBRACE, KEY_O,
        KEY_U, KEY_LEFTBRACE, KEY_I, KEY_P, KEY_ENTER, KEY_L, KEY_J, KEY_APOSTROPHE,
        KEY_K, KEY_SEMICOLON, KEY_BACKSLASH, KEY_COMMA, KEY_SLASH, KEY_N, KEY_M, KEY_DOT,
        KEY_TAB, KEY_SPACE, KEY_GRAVE, KEY_DELETE, 0, 0, 0, KEY_LEFTMETA,
        KEY_LEFTSHIFT, KEY_CAPSLOCK, KEY_LEFTALT, KEY_LEFTCTRL, KEY_RIGHTSHIFT, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        KEY_LEFT, KEY_RIGHT, KEY_DOWN, KEY_UP, 0
};

struct nkbd {
        unsigned char keycode[128];
        struct input_dev *dev;
        struct serio *serio;
        char phys[32];
};

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

        /* invalid scan codes are probably the init sequence, so we ignore them */
        if (nkbd->keycode[data & NKBD_KEY]) {
                input_report_key(nkbd->dev, nkbd->keycode[data & NKBD_KEY], data & NKBD_PRESS);
                input_sync(nkbd->dev);
        }

        else if (data == 0xe7) /* end of init sequence */
                printk(KERN_INFO "input: %s on %s\n", nkbd->dev->name, serio->phys);
        return IRQ_HANDLED;

}

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

        nkbd = kzalloc_obj(*nkbd);
        input_dev = input_allocate_device();
        if (!nkbd || !input_dev)
                goto fail1;

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

        input_dev->name = "Newton Keyboard";
        input_dev->phys = nkbd->phys;
        input_dev->id.bustype = BUS_RS232;
        input_dev->id.vendor = SERIO_NEWTON;
        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 = nkbd->keycode;
        input_dev->keycodesize = sizeof(unsigned char);
        input_dev->keycodemax = ARRAY_SIZE(nkbd_keycode);
        for (i = 0; i < 128; i++)
                set_bit(nkbd->keycode[i], input_dev->keybit);
        clear_bit(0, input_dev->keybit);

        serio_set_drvdata(serio, nkbd);

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

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

        return 0;

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

static void nkbd_disconnect(struct serio *serio)
{
        struct nkbd *nkbd = serio_get_drvdata(serio);

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

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

MODULE_DEVICE_TABLE(serio, nkbd_serio_ids);

static struct serio_driver nkbd_drv = {
        .driver         = {
                .name   = "newtonkbd",
        },
        .description    = DRIVER_DESC,
        .id_table       = nkbd_serio_ids,
        .interrupt      = nkbd_interrupt,
        .connect        = nkbd_connect,
        .disconnect     = nkbd_disconnect,
};

module_serio_driver(nkbd_drv);