/*
 *  Copyright (C) 2004 by Jan-Benedict Glaw <jbglaw@lug-owl.de>
 */

/*
 * LK keyboard driver for Linux, based on sunkbd.c (C) by Vojtech Pavlik
 */

/*
 * DEC LK201 and LK401 keyboard driver for Linux (primary for DECstations
 * and VAXstations, but can also be used on any standard RS232 with an
 * adaptor).
 *
 * DISCLAIMER: This works for _me_. If you break anything by using the
 * information given below, I will _not_ be liable!
 *
 * RJ10 pinout:         To DE9:         Or DB25:
 *      1 - RxD <---->  Pin 3 (TxD) <-> Pin 2 (TxD)
 *      2 - GND <---->  Pin 5 (GND) <-> Pin 7 (GND)
 *      4 - TxD <---->  Pin 2 (RxD) <-> Pin 3 (RxD)
 *      3 - +12V (from HDD drive connector), DON'T connect to DE9 or DB25!!!
 *
 * Pin numbers for DE9 and DB25 are noted on the plug (quite small:). For
 * RJ10, it's like this:
 *
 *      __=__   Hold the plug in front of you, cable downwards,
 *     /___/|   nose is hidden behind the plug. Now, pin 1 is at
 *    |1234||   the left side, pin 4 at the right and 2 and 3 are
 *    |IIII||   in between, of course:)
 *    |    ||
 *    |____|/
 *      ||      So the adaptor consists of three connected cables
 *      ||      for data transmission (RxD and TxD) and signal ground.
 *              Additionally, you have to get +12V from somewhere.
 * Most easily, you'll get that from a floppy or HDD power connector.
 * It's the yellow cable there (black is ground and red is +5V).
 *
 * The keyboard and all the commands it understands are documented in
 * "VCB02 Video Subsystem - Technical Manual", EK-104AA-TM-001. This
 * document is LK201 specific, but LK401 is mostly compatible. It comes
 * up in LK201 mode and doesn't report any of the additional keys it
 * has. These need to be switched on with the LK_CMD_ENABLE_LK401
 * command. You'll find this document (scanned .pdf file) on MANX,
 * a search engine specific to DEC documentation. Try
 * http://www.vt100.net/manx/details?pn=EK-104AA-TM-001;id=21;cp=1
 */

/*
 * 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/delay.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     "LK keyboard driver"

MODULE_AUTHOR("Jan-Benedict Glaw <jbglaw@lug-owl.de>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

/*
 * Known parameters:
 *      bell_volume
 *      keyclick_volume
 *      ctrlclick_volume
 *
 * Please notice that there's not yet an API to set these at runtime.
 */
static int bell_volume = 100; /* % */
module_param(bell_volume, int, 0);
MODULE_PARM_DESC(bell_volume, "Bell volume (in %). default is 100%");

static int keyclick_volume = 100; /* % */
module_param(keyclick_volume, int, 0);
MODULE_PARM_DESC(keyclick_volume, "Keyclick volume (in %), default is 100%");

static int ctrlclick_volume = 100; /* % */
module_param(ctrlclick_volume, int, 0);
MODULE_PARM_DESC(ctrlclick_volume, "Ctrlclick volume (in %), default is 100%");

static int lk201_compose_is_alt;
module_param(lk201_compose_is_alt, int, 0);
MODULE_PARM_DESC(lk201_compose_is_alt,
                 "If set non-zero, LK201' Compose key will act as an Alt key");



#undef LKKBD_DEBUG
#ifdef LKKBD_DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...) do {} while (0)
#endif

/* LED control */
#define LK_LED_WAIT             0x81
#define LK_LED_COMPOSE          0x82
#define LK_LED_SHIFTLOCK        0x84
#define LK_LED_SCROLLLOCK       0x88
#define LK_CMD_LED_ON           0x13
#define LK_CMD_LED_OFF          0x11

/* Mode control */
#define LK_MODE_DOWN            0x80
#define LK_MODE_AUTODOWN        0x82
#define LK_MODE_UPDOWN          0x86
#define LK_CMD_SET_MODE(mode, div)      ((mode) | ((div) << 3))

/* Misc commands */
#define LK_CMD_ENABLE_KEYCLICK  0x1b
#define LK_CMD_DISABLE_KEYCLICK 0x99
#define LK_CMD_DISABLE_BELL     0xa1
#define LK_CMD_SOUND_BELL       0xa7
#define LK_CMD_ENABLE_BELL      0x23
#define LK_CMD_DISABLE_CTRCLICK 0xb9
#define LK_CMD_ENABLE_CTRCLICK  0xbb
#define LK_CMD_SET_DEFAULTS     0xd3
#define LK_CMD_POWERCYCLE_RESET 0xfd
#define LK_CMD_ENABLE_LK401     0xe9
#define LK_CMD_REQUEST_ID       0xab

/* Misc responses from keyboard */
#define LK_STUCK_KEY            0x3d
#define LK_SELFTEST_FAILED      0x3e
#define LK_ALL_KEYS_UP          0xb3
#define LK_METRONOME            0xb4
#define LK_OUTPUT_ERROR         0xb5
#define LK_INPUT_ERROR          0xb6
#define LK_KBD_LOCKED           0xb7
#define LK_KBD_TEST_MODE_ACK    0xb8
#define LK_PREFIX_KEY_DOWN      0xb9
#define LK_MODE_CHANGE_ACK      0xba
#define LK_RESPONSE_RESERVED    0xbb

#define LK_NUM_KEYCODES         256
#define LK_NUM_IGNORE_BYTES     6

static unsigned short lkkbd_keycode[LK_NUM_KEYCODES] = {
        [0x56] = KEY_F1,
        [0x57] = KEY_F2,
        [0x58] = KEY_F3,
        [0x59] = KEY_F4,
        [0x5a] = KEY_F5,
        [0x64] = KEY_F6,
        [0x65] = KEY_F7,
        [0x66] = KEY_F8,
        [0x67] = KEY_F9,
        [0x68] = KEY_F10,
        [0x71] = KEY_F11,
        [0x72] = KEY_F12,
        [0x73] = KEY_F13,
        [0x74] = KEY_F14,
        [0x7c] = KEY_F15,
        [0x7d] = KEY_F16,
        [0x80] = KEY_F17,
        [0x81] = KEY_F18,
        [0x82] = KEY_F19,
        [0x83] = KEY_F20,
        [0x8a] = KEY_FIND,
        [0x8b] = KEY_INSERT,
        [0x8c] = KEY_DELETE,
        [0x8d] = KEY_SELECT,
        [0x8e] = KEY_PAGEUP,
        [0x8f] = KEY_PAGEDOWN,
        [0x92] = KEY_KP0,
        [0x94] = KEY_KPDOT,
        [0x95] = KEY_KPENTER,
        [0x96] = KEY_KP1,
        [0x97] = KEY_KP2,
        [0x98] = KEY_KP3,
        [0x99] = KEY_KP4,
        [0x9a] = KEY_KP5,
        [0x9b] = KEY_KP6,
        [0x9c] = KEY_KPCOMMA,
        [0x9d] = KEY_KP7,
        [0x9e] = KEY_KP8,
        [0x9f] = KEY_KP9,
        [0xa0] = KEY_KPMINUS,
        [0xa1] = KEY_PROG1,
        [0xa2] = KEY_PROG2,
        [0xa3] = KEY_PROG3,
        [0xa4] = KEY_PROG4,
        [0xa7] = KEY_LEFT,
        [0xa8] = KEY_RIGHT,
        [0xa9] = KEY_DOWN,
        [0xaa] = KEY_UP,
        [0xab] = KEY_RIGHTSHIFT,
        [0xac] = KEY_LEFTALT,
        [0xad] = KEY_COMPOSE, /* Right Compose, that is. */
        [0xae] = KEY_LEFTSHIFT, /* Same as KEY_RIGHTSHIFT on LK201 */
        [0xaf] = KEY_LEFTCTRL,
        [0xb0] = KEY_CAPSLOCK,
        [0xb1] = KEY_COMPOSE, /* Left Compose, that is. */
        [0xb2] = KEY_RIGHTALT,
        [0xbc] = KEY_BACKSPACE,
        [0xbd] = KEY_ENTER,
        [0xbe] = KEY_TAB,
        [0xbf] = KEY_ESC,
        [0xc0] = KEY_1,
        [0xc1] = KEY_Q,
        [0xc2] = KEY_A,
        [0xc3] = KEY_Z,
        [0xc5] = KEY_2,
        [0xc6] = KEY_W,
        [0xc7] = KEY_S,
        [0xc8] = KEY_X,
        [0xc9] = KEY_102ND,
        [0xcb] = KEY_3,
        [0xcc] = KEY_E,
        [0xcd] = KEY_D,
        [0xce] = KEY_C,
        [0xd0] = KEY_4,
        [0xd1] = KEY_R,
        [0xd2] = KEY_F,
        [0xd3] = KEY_V,
        [0xd4] = KEY_SPACE,
        [0xd6] = KEY_5,
        [0xd7] = KEY_T,
        [0xd8] = KEY_G,
        [0xd9] = KEY_B,
        [0xdb] = KEY_6,
        [0xdc] = KEY_Y,
        [0xdd] = KEY_H,
        [0xde] = KEY_N,
        [0xe0] = KEY_7,
        [0xe1] = KEY_U,
        [0xe2] = KEY_J,
        [0xe3] = KEY_M,
        [0xe5] = KEY_8,
        [0xe6] = KEY_I,
        [0xe7] = KEY_K,
        [0xe8] = KEY_COMMA,
        [0xea] = KEY_9,
        [0xeb] = KEY_O,
        [0xec] = KEY_L,
        [0xed] = KEY_DOT,
        [0xef] = KEY_0,
        [0xf0] = KEY_P,
        [0xf2] = KEY_SEMICOLON,
        [0xf3] = KEY_SLASH,
        [0xf5] = KEY_EQUAL,
        [0xf6] = KEY_RIGHTBRACE,
        [0xf7] = KEY_BACKSLASH,
        [0xf9] = KEY_MINUS,
        [0xfa] = KEY_LEFTBRACE,
        [0xfb] = KEY_APOSTROPHE,
};

#define CHECK_LED(LK, VAR_ON, VAR_OFF, LED, BITS) do {          \
        if (test_bit(LED, (LK)->dev->led))                      \
                VAR_ON |= BITS;                                 \
        else                                                    \
                VAR_OFF |= BITS;                                \
        } while (0)

/*
 * Per-keyboard data
 */
struct lkkbd {
        unsigned short keycode[LK_NUM_KEYCODES];
        int ignore_bytes;
        unsigned char id[LK_NUM_IGNORE_BYTES];
        struct input_dev *dev;
        struct serio *serio;
        struct work_struct tq;
        char name[64];
        char phys[32];
        char type;
        int bell_volume;
        int keyclick_volume;
        int ctrlclick_volume;
};

#ifdef LKKBD_DEBUG
/*
 * Responses from the keyboard and mapping back to their names.
 */
static struct {
        unsigned char value;
        unsigned char *name;
} lk_response[] = {
#define RESPONSE(x) { .value = (x), .name = #x, }
        RESPONSE(LK_STUCK_KEY),
        RESPONSE(LK_SELFTEST_FAILED),
        RESPONSE(LK_ALL_KEYS_UP),
        RESPONSE(LK_METRONOME),
        RESPONSE(LK_OUTPUT_ERROR),
        RESPONSE(LK_INPUT_ERROR),
        RESPONSE(LK_KBD_LOCKED),
        RESPONSE(LK_KBD_TEST_MODE_ACK),
        RESPONSE(LK_PREFIX_KEY_DOWN),
        RESPONSE(LK_MODE_CHANGE_ACK),
        RESPONSE(LK_RESPONSE_RESERVED),
#undef RESPONSE
};

static unsigned char *response_name(unsigned char value)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(lk_response); i++)
                if (lk_response[i].value == value)
                        return lk_response[i].name;

        return "<unknown>";
}
#endif /* LKKBD_DEBUG */

/*
 * Calculate volume parameter byte for a given volume.
 */
static unsigned char volume_to_hw(int volume_percent)
{
        unsigned char ret = 0;

        if (volume_percent < 0)
                volume_percent = 0;
        if (volume_percent > 100)
                volume_percent = 100;

        if (volume_percent >= 0)
                ret = 7;
        if (volume_percent >= 13)       /* 12.5 */
                ret = 6;
        if (volume_percent >= 25)
                ret = 5;
        if (volume_percent >= 38)       /* 37.5 */
                ret = 4;
        if (volume_percent >= 50)
                ret = 3;
        if (volume_percent >= 63)       /* 62.5 */
                ret = 2;                /* This is the default volume */
        if (volume_percent >= 75)
                ret = 1;
        if (volume_percent >= 88)       /* 87.5 */
                ret = 0;

        ret |= 0x80;

        return ret;
}

static void lkkbd_detection_done(struct lkkbd *lk)
{
        int i;

        /*
         * Reset setting for Compose key. Let Compose be KEY_COMPOSE.
         */
        lk->keycode[0xb1] = KEY_COMPOSE;

        /*
         * Print keyboard name and modify Compose=Alt on user's request.
         */
        switch (lk->id[4]) {
        case 1:
                strlcpy(lk->name, "DEC LK201 keyboard", sizeof(lk->name));

                if (lk201_compose_is_alt)
                        lk->keycode[0xb1] = KEY_LEFTALT;
                break;

        case 2:
                strlcpy(lk->name, "DEC LK401 keyboard", sizeof(lk->name));
                break;

        default:
                strlcpy(lk->name, "Unknown DEC keyboard", sizeof(lk->name));
                printk(KERN_ERR
                        "lkkbd: keyboard on %s is unknown, please report to "
                        "Jan-Benedict Glaw <jbglaw@lug-owl.de>\n", lk->phys);
                printk(KERN_ERR "lkkbd: keyboard ID'ed as:");
                for (i = 0; i < LK_NUM_IGNORE_BYTES; i++)
                        printk(" 0x%02x", lk->id[i]);
                printk("\n");
                break;
        }

        printk(KERN_INFO "lkkbd: keyboard on %s identified as: %s\n",
                lk->phys, lk->name);

        /*
         * Report errors during keyboard boot-up.
         */
        switch (lk->id[2]) {
        case 0x00:
                /* All okay */
                break;

        case LK_STUCK_KEY:
                printk(KERN_ERR "lkkbd: Stuck key on keyboard at %s\n",
                        lk->phys);
                break;

        case LK_SELFTEST_FAILED:
                printk(KERN_ERR
                        "lkkbd: Selftest failed on keyboard at %s, "
                        "keyboard may not work properly\n", lk->phys);
                break;

        default:
                printk(KERN_ERR
                        "lkkbd: Unknown error %02x on keyboard at %s\n",
                        lk->id[2], lk->phys);
                break;
        }

        /*
         * Try to hint user if there's a stuck key.
         */
        if (lk->id[2] == LK_STUCK_KEY && lk->id[3] != 0)
                printk(KERN_ERR
                        "Scancode of stuck key is 0x%02x, keycode is 0x%04x\n",
                        lk->id[3], lk->keycode[lk->id[3]]);
}

/*
 * lkkbd_interrupt() is called by the low level driver when a character
 * is received.
 */
static irqreturn_t lkkbd_interrupt(struct serio *serio,
                                   unsigned char data, unsigned int flags)
{
        struct lkkbd *lk = serio_get_drvdata(serio);
        struct input_dev *input_dev = lk->dev;
        unsigned int keycode;
        int i;

        DBG(KERN_INFO "Got byte 0x%02x\n", data);

        if (lk->ignore_bytes > 0) {
                DBG(KERN_INFO "Ignoring a byte on %s\n", lk->name);
                lk->id[LK_NUM_IGNORE_BYTES - lk->ignore_bytes--] = data;

                if (lk->ignore_bytes == 0)
                        lkkbd_detection_done(lk);

                return IRQ_HANDLED;
        }

        switch (data) {
        case LK_ALL_KEYS_UP:
                for (i = 0; i < ARRAY_SIZE(lkkbd_keycode); i++)
                        input_report_key(input_dev, lk->keycode[i], 0);
                input_sync(input_dev);
                break;

        case 0x01:
                DBG(KERN_INFO "Got 0x01, scheduling re-initialization\n");
                lk->ignore_bytes = LK_NUM_IGNORE_BYTES;
                lk->id[LK_NUM_IGNORE_BYTES - lk->ignore_bytes--] = data;
                schedule_work(&lk->tq);
                break;

        case LK_METRONOME:
        case LK_OUTPUT_ERROR:
        case LK_INPUT_ERROR:
        case LK_KBD_LOCKED:
        case LK_KBD_TEST_MODE_ACK:
        case LK_PREFIX_KEY_DOWN:
        case LK_MODE_CHANGE_ACK:
        case LK_RESPONSE_RESERVED:
                DBG(KERN_INFO "Got %s and don't know how to handle...\n",
                        response_name(data));
                break;

        default:
                keycode = lk->keycode[data];
                if (keycode != KEY_RESERVED) {
                        input_report_key(input_dev, keycode,
                                         !test_bit(keycode, input_dev->key));
                        input_sync(input_dev);
                } else {
                        printk(KERN_WARNING
                                "%s: Unknown key with scancode 0x%02x on %s.\n",
                                __FILE__, data, lk->name);
                }
        }

        return IRQ_HANDLED;
}

static void lkkbd_toggle_leds(struct lkkbd *lk)
{
        struct serio *serio = lk->serio;
        unsigned char leds_on = 0;
        unsigned char leds_off = 0;

        CHECK_LED(lk, leds_on, leds_off, LED_CAPSL, LK_LED_SHIFTLOCK);
        CHECK_LED(lk, leds_on, leds_off, LED_COMPOSE, LK_LED_COMPOSE);
        CHECK_LED(lk, leds_on, leds_off, LED_SCROLLL, LK_LED_SCROLLLOCK);
        CHECK_LED(lk, leds_on, leds_off, LED_SLEEP, LK_LED_WAIT);
        if (leds_on != 0) {
                serio_write(serio, LK_CMD_LED_ON);
                serio_write(serio, leds_on);
        }
        if (leds_off != 0) {
                serio_write(serio, LK_CMD_LED_OFF);
                serio_write(serio, leds_off);
        }
}

static void lkkbd_toggle_keyclick(struct lkkbd *lk, bool on)
{
        struct serio *serio = lk->serio;

        if (on) {
                DBG("%s: Activating key clicks\n", __func__);
                serio_write(serio, LK_CMD_ENABLE_KEYCLICK);
                serio_write(serio, volume_to_hw(lk->keyclick_volume));
                serio_write(serio, LK_CMD_ENABLE_CTRCLICK);
                serio_write(serio, volume_to_hw(lk->ctrlclick_volume));
        } else {
                DBG("%s: Deactivating key clicks\n", __func__);
                serio_write(serio, LK_CMD_DISABLE_KEYCLICK);
                serio_write(serio, LK_CMD_DISABLE_CTRCLICK);
        }

}

/*
 * lkkbd_event() handles events from the input module.
 */
static int lkkbd_event(struct input_dev *dev,
                        unsigned int type, unsigned int code, int value)
{
        struct lkkbd *lk = input_get_drvdata(dev);

        switch (type) {
        case EV_LED:
                lkkbd_toggle_leds(lk);
                return 0;

        case EV_SND:
                switch (code) {
                case SND_CLICK:
                        lkkbd_toggle_keyclick(lk, value);
                        return 0;

                case SND_BELL:
                        if (value != 0)
                                serio_write(lk->serio, LK_CMD_SOUND_BELL);

                        return 0;
                }

                break;

        default:
                printk(KERN_ERR "%s(): Got unknown type %d, code %d, value %d\n",
                        __func__, type, code, value);
        }

        return -1;
}

/*
 * lkkbd_reinit() sets leds and beeps to a state the computer remembers they
 * were in.
 */
static void lkkbd_reinit(struct work_struct *work)
{
        struct lkkbd *lk = container_of(work, struct lkkbd, tq);
        int division;

        /* Ask for ID */
        serio_write(lk->serio, LK_CMD_REQUEST_ID);

        /* Reset parameters */
        serio_write(lk->serio, LK_CMD_SET_DEFAULTS);

        /* Set LEDs */
        lkkbd_toggle_leds(lk);

        /*
         * Try to activate extended LK401 mode. This command will
         * only work with a LK401 keyboard and grants access to
         * LAlt, RAlt, RCompose and RShift.
         */
        serio_write(lk->serio, LK_CMD_ENABLE_LK401);

        /* Set all keys to UPDOWN mode */
        for (division = 1; division <= 14; division++)
                serio_write(lk->serio,
                            LK_CMD_SET_MODE(LK_MODE_UPDOWN, division));

        /* Enable bell and set volume */
        serio_write(lk->serio, LK_CMD_ENABLE_BELL);
        serio_write(lk->serio, volume_to_hw(lk->bell_volume));

        /* Enable/disable keyclick (and possibly set volume) */
        lkkbd_toggle_keyclick(lk, test_bit(SND_CLICK, lk->dev->snd));

        /* Sound the bell if needed */
        if (test_bit(SND_BELL, lk->dev->snd))
                serio_write(lk->serio, LK_CMD_SOUND_BELL);
}

/*
 * lkkbd_connect() probes for a LK keyboard and fills the necessary structures.
 */
static int lkkbd_connect(struct serio *serio, struct serio_driver *drv)
{
        struct lkkbd *lk;
        struct input_dev *input_dev;
        int i;
        int err;

        lk = kzalloc(sizeof(struct lkkbd), GFP_KERNEL);
        input_dev = input_allocate_device();
        if (!lk || !input_dev) {
                err = -ENOMEM;
                goto fail1;
        }

        lk->serio = serio;
        lk->dev = input_dev;
        INIT_WORK(&lk->tq, lkkbd_reinit);
        lk->bell_volume = bell_volume;
        lk->keyclick_volume = keyclick_volume;
        lk->ctrlclick_volume = ctrlclick_volume;
        memcpy(lk->keycode, lkkbd_keycode, sizeof(lk->keycode));

        strlcpy(lk->name, "DEC LK keyboard", sizeof(lk->name));
        snprintf(lk->phys, sizeof(lk->phys), "%s/input0", serio->phys);

        input_dev->name = lk->name;
        input_dev->phys = lk->phys;
        input_dev->id.bustype = BUS_RS232;
        input_dev->id.vendor = SERIO_LKKBD;
        input_dev->id.product = 0;
        input_dev->id.version = 0x0100;
        input_dev->dev.parent = &serio->dev;
        input_dev->event = lkkbd_event;

        input_set_drvdata(input_dev, lk);

        __set_bit(EV_KEY, input_dev->evbit);
        __set_bit(EV_LED, input_dev->evbit);
        __set_bit(EV_SND, input_dev->evbit);
        __set_bit(EV_REP, input_dev->evbit);
        __set_bit(LED_CAPSL, input_dev->ledbit);
        __set_bit(LED_SLEEP, input_dev->ledbit);
        __set_bit(LED_COMPOSE, input_dev->ledbit);
        __set_bit(LED_SCROLLL, input_dev->ledbit);
        __set_bit(SND_BELL, input_dev->sndbit);
        __set_bit(SND_CLICK, input_dev->sndbit);

        input_dev->keycode = lk->keycode;
        input_dev->keycodesize = sizeof(lk->keycode[0]);
        input_dev->keycodemax = ARRAY_SIZE(lk->keycode);

        for (i = 0; i < LK_NUM_KEYCODES; i++)
                __set_bit(lk->keycode[i], input_dev->keybit);
        __clear_bit(KEY_RESERVED, input_dev->keybit);

        serio_set_drvdata(serio, lk);

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

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

        serio_write(lk->serio, LK_CMD_POWERCYCLE_RESET);

        return 0;

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

/*
 * lkkbd_disconnect() unregisters and closes behind us.
 */
static void lkkbd_disconnect(struct serio *serio)
{
        struct lkkbd *lk = serio_get_drvdata(serio);

        input_get_device(lk->dev);
        input_unregister_device(lk->dev);
        serio_close(serio);
        serio_set_drvdata(serio, NULL);
        input_put_device(lk->dev);
        kfree(lk);
}

static struct serio_device_id lkkbd_serio_ids[] = {
        {
                .type   = SERIO_RS232,
                .proto  = SERIO_LKKBD,
                .id     = SERIO_ANY,
                .extra  = SERIO_ANY,
        },
        { 0 }
};

MODULE_DEVICE_TABLE(serio, lkkbd_serio_ids);

static struct serio_driver lkkbd_drv = {
        .driver         = {
                .name   = "lkkbd",
        },
        .description    = DRIVER_DESC,
        .id_table       = lkkbd_serio_ids,
        .connect        = lkkbd_connect,
        .disconnect     = lkkbd_disconnect,
        .interrupt      = lkkbd_interrupt,
};

module_serio_driver(lkkbd_drv);