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

/*
 * Sun keyboard driver for Linux
 */

#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/workqueue.h>

#define DRIVER_DESC     "Sun keyboard driver"

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

static unsigned char sunkbd_keycode[128] = {
          0,128,114,129,115, 59, 60, 68, 61, 87, 62, 88, 63,100, 64,112,
         65, 66, 67, 56,103,119, 99, 70,105,130,131,108,106,  1,  2,  3,
          4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 41, 14,110,113, 98, 55,
        116,132, 83,133,102, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
         26, 27,111,127, 71, 72, 73, 74,134,135,107,  0, 29, 30, 31, 32,
         33, 34, 35, 36, 37, 38, 39, 40, 43, 28, 96, 75, 76, 77, 82,136,
        104,137, 69, 42, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54,101,
         79, 80, 81,  0,  0,  0,138, 58,125, 57,126,109, 86, 78
};

#define SUNKBD_CMD_RESET        0x1
#define SUNKBD_CMD_BELLON       0x2
#define SUNKBD_CMD_BELLOFF      0x3
#define SUNKBD_CMD_CLICK        0xa
#define SUNKBD_CMD_NOCLICK      0xb
#define SUNKBD_CMD_SETLED       0xe
#define SUNKBD_CMD_LAYOUT       0xf

#define SUNKBD_RET_RESET        0xff
#define SUNKBD_RET_ALLUP        0x7f
#define SUNKBD_RET_LAYOUT       0xfe

#define SUNKBD_LAYOUT_5_MASK    0x20
#define SUNKBD_RELEASE          0x80
#define SUNKBD_KEY              0x7f

/*
 * Per-keyboard data.
 */

struct sunkbd {
        unsigned char keycode[ARRAY_SIZE(sunkbd_keycode)];
        struct input_dev *dev;
        struct serio *serio;
        struct work_struct tq;
        wait_queue_head_t wait;
        char name[64];
        char phys[32];
        char type;
        bool enabled;
        volatile s8 reset;
        volatile s8 layout;
};

/*
 * sunkbd_interrupt() is called by the low level driver when a character
 * is received.
 */

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

        if (sunkbd->reset <= -1) {
                /*
                 * If cp[i] is 0xff, sunkbd->reset will stay -1.
                 * The keyboard sends 0xff 0xff 0xID on powerup.
                 */
                sunkbd->reset = data;
                wake_up_interruptible(&sunkbd->wait);
                goto out;
        }

        if (sunkbd->layout == -1) {
                sunkbd->layout = data;
                wake_up_interruptible(&sunkbd->wait);
                goto out;
        }

        switch (data) {

        case SUNKBD_RET_RESET:
                if (sunkbd->enabled)
                        schedule_work(&sunkbd->tq);
                sunkbd->reset = -1;
                break;

        case SUNKBD_RET_LAYOUT:
                sunkbd->layout = -1;
                break;

        case SUNKBD_RET_ALLUP: /* All keys released */
                break;

        default:
                if (!sunkbd->enabled)
                        break;

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

/*
 * sunkbd_event() handles events from the input module.
 */

static int sunkbd_event(struct input_dev *dev,
                        unsigned int type, unsigned int code, int value)
{
        struct sunkbd *sunkbd = input_get_drvdata(dev);

        switch (type) {

        case EV_LED:

                serio_write(sunkbd->serio, SUNKBD_CMD_SETLED);
                serio_write(sunkbd->serio,
                        (!!test_bit(LED_CAPSL,   dev->led) << 3) |
                        (!!test_bit(LED_SCROLLL, dev->led) << 2) |
                        (!!test_bit(LED_COMPOSE, dev->led) << 1) |
                         !!test_bit(LED_NUML,    dev->led));
                return 0;

        case EV_SND:

                switch (code) {

                case SND_CLICK:
                        serio_write(sunkbd->serio, SUNKBD_CMD_NOCLICK - value);
                        return 0;

                case SND_BELL:
                        serio_write(sunkbd->serio, SUNKBD_CMD_BELLOFF - value);
                        return 0;
                }

                break;
        }

        return -1;
}

/*
 * sunkbd_initialize() checks for a Sun keyboard attached, and determines
 * its type.
 */

static int sunkbd_initialize(struct sunkbd *sunkbd)
{
        sunkbd->reset = -2;
        serio_write(sunkbd->serio, SUNKBD_CMD_RESET);
        wait_event_interruptible_timeout(sunkbd->wait, sunkbd->reset >= 0, HZ);
        if (sunkbd->reset < 0)
                return -1;

        sunkbd->type = sunkbd->reset;

        if (sunkbd->type == 4) {        /* Type 4 keyboard */
                sunkbd->layout = -2;
                serio_write(sunkbd->serio, SUNKBD_CMD_LAYOUT);
                wait_event_interruptible_timeout(sunkbd->wait,
                                                 sunkbd->layout >= 0, HZ / 4);
                if (sunkbd->layout < 0)
                        return -1;
                if (sunkbd->layout & SUNKBD_LAYOUT_5_MASK)
                        sunkbd->type = 5;
        }

        return 0;
}

/*
 * sunkbd_set_leds_beeps() sets leds and beeps to a state the computer remembers
 * they were in.
 */

static void sunkbd_set_leds_beeps(struct sunkbd *sunkbd)
{
        serio_write(sunkbd->serio, SUNKBD_CMD_SETLED);
        serio_write(sunkbd->serio,
                (!!test_bit(LED_CAPSL,   sunkbd->dev->led) << 3) |
                (!!test_bit(LED_SCROLLL, sunkbd->dev->led) << 2) |
                (!!test_bit(LED_COMPOSE, sunkbd->dev->led) << 1) |
                 !!test_bit(LED_NUML,    sunkbd->dev->led));
        serio_write(sunkbd->serio,
                SUNKBD_CMD_NOCLICK - !!test_bit(SND_CLICK, sunkbd->dev->snd));
        serio_write(sunkbd->serio,
                SUNKBD_CMD_BELLOFF - !!test_bit(SND_BELL, sunkbd->dev->snd));
}


/*
 * sunkbd_reinit() wait for the keyboard reset to complete and restores state
 * of leds and beeps.
 */

static void sunkbd_reinit(struct work_struct *work)
{
        struct sunkbd *sunkbd = container_of(work, struct sunkbd, tq);

        /*
         * It is OK that we check sunkbd->enabled without pausing serio,
         * as we only want to catch true->false transition that will
         * happen once and we will be woken up for it.
         */
        wait_event_interruptible_timeout(sunkbd->wait,
                                         sunkbd->reset >= 0 || !sunkbd->enabled,
                                         HZ);

        if (sunkbd->reset >= 0 && sunkbd->enabled)
                sunkbd_set_leds_beeps(sunkbd);
}

static void sunkbd_enable(struct sunkbd *sunkbd, bool enable)
{
        scoped_guard(serio_pause_rx, sunkbd->serio)
                sunkbd->enabled = enable;

        if (!enable) {
                wake_up_interruptible(&sunkbd->wait);
                cancel_work_sync(&sunkbd->tq);
        }
}

/*
 * sunkbd_connect() probes for a Sun keyboard and fills the necessary
 * structures.
 */

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

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

        sunkbd->serio = serio;
        sunkbd->dev = input_dev;
        init_waitqueue_head(&sunkbd->wait);
        INIT_WORK(&sunkbd->tq, sunkbd_reinit);
        snprintf(sunkbd->phys, sizeof(sunkbd->phys), "%s/input0", serio->phys);

        serio_set_drvdata(serio, sunkbd);

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

        if (sunkbd_initialize(sunkbd) < 0) {
                err = -ENODEV;
                goto fail3;
        }

        snprintf(sunkbd->name, sizeof(sunkbd->name),
                 "Sun Type %d keyboard", sunkbd->type);
        memcpy(sunkbd->keycode, sunkbd_keycode, sizeof(sunkbd->keycode));

        input_dev->name = sunkbd->name;
        input_dev->phys = sunkbd->phys;
        input_dev->id.bustype = BUS_RS232;
        input_dev->id.vendor  = SERIO_SUNKBD;
        input_dev->id.product = sunkbd->type;
        input_dev->id.version = 0x0100;
        input_dev->dev.parent = &serio->dev;

        input_set_drvdata(input_dev, sunkbd);

        input_dev->event = sunkbd_event;

        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_LED) |
                BIT_MASK(EV_SND) | BIT_MASK(EV_REP);
        input_dev->ledbit[0] = BIT_MASK(LED_CAPSL) | BIT_MASK(LED_COMPOSE) |
                BIT_MASK(LED_SCROLLL) | BIT_MASK(LED_NUML);
        input_dev->sndbit[0] = BIT_MASK(SND_CLICK) | BIT_MASK(SND_BELL);

        input_dev->keycode = sunkbd->keycode;
        input_dev->keycodesize = sizeof(unsigned char);
        input_dev->keycodemax = ARRAY_SIZE(sunkbd_keycode);
        for (i = 0; i < ARRAY_SIZE(sunkbd_keycode); i++)
                __set_bit(sunkbd->keycode[i], input_dev->keybit);
        __clear_bit(KEY_RESERVED, input_dev->keybit);

        sunkbd_enable(sunkbd, true);

        err = input_register_device(sunkbd->dev);
        if (err)
                goto fail4;

        return 0;

 fail4: sunkbd_enable(sunkbd, false);
 fail3: serio_close(serio);
 fail2: serio_set_drvdata(serio, NULL);
 fail1: input_free_device(input_dev);
        kfree(sunkbd);
        return err;
}

/*
 * sunkbd_disconnect() unregisters and closes behind us.
 */

static void sunkbd_disconnect(struct serio *serio)
{
        struct sunkbd *sunkbd = serio_get_drvdata(serio);

        sunkbd_enable(sunkbd, false);
        input_unregister_device(sunkbd->dev);
        serio_close(serio);
        serio_set_drvdata(serio, NULL);
        kfree(sunkbd);
}

static const struct serio_device_id sunkbd_serio_ids[] = {
        {
                .type   = SERIO_RS232,
                .proto  = SERIO_SUNKBD,
                .id     = SERIO_ANY,
                .extra  = SERIO_ANY,
        },
        {
                .type   = SERIO_RS232,
                .proto  = SERIO_UNKNOWN, /* sunkbd does probe */
                .id     = SERIO_ANY,
                .extra  = SERIO_ANY,
        },
        { 0 }
};

MODULE_DEVICE_TABLE(serio, sunkbd_serio_ids);

static struct serio_driver sunkbd_drv = {
        .driver         = {
                .name   = "sunkbd",
        },
        .description    = DRIVER_DESC,
        .id_table       = sunkbd_serio_ids,
        .interrupt      = sunkbd_interrupt,
        .connect        = sunkbd_connect,
        .disconnect     = sunkbd_disconnect,
};

module_serio_driver(sunkbd_drv);