lkkbd.c

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/*
 *  Copyright (C) 2004 by Jan-Benedict Glaw <[email protected]>
 */

/*
 * 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/init.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/workqueue.h>

#define DRIVER_DESC "LK keyboard driver"

MODULE_AUTHOR("Jan-Benedict Glaw <[email protected]>");
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 <[email protected]>\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);