source: mainline/uspace/drv/bus/usb/usbhid/kbd/kbddev.c@ 9871bca

/*
 * Copyright (c) 2011 Lubos Slovak
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup drvusbhid
 * @{
 */
/**
 * @file
 * USB HID keyboard device structure and API.
 */

#include <errno.h>
#include <str_error.h>
#include <stdio.h>

#include <io/keycode.h>
#include <io/console.h>
#include <ipc/kbdev.h>
#include <async.h>
#include <fibril.h>
#include <fibril_synch.h>

#include <ddf/log.h>

#include <usb/usb.h>
#include <usb/dev/dp.h>
#include <usb/dev/request.h>
#include <usb/hid/hid.h>
#include <usb/dev/pipes.h>
#include <usb/debug.h>
#include <usb/hid/hidparser.h>
#include <usb/classes/classes.h>
#include <usb/hid/usages/core.h>
#include <usb/hid/request.h>
#include <usb/hid/hidreport.h>
#include <usb/hid/usages/led.h>

#include <usb/dev/driver.h>

#include "kbddev.h"

#include "conv.h"
#include "kbdrepeat.h"

#include "../usbhid.h"

/*----------------------------------------------------------------------------*/

static const unsigned DEFAULT_ACTIVE_MODS = KM_NUM_LOCK;

static const uint8_t ERROR_ROLLOVER = 1;

/** Default idle rate for keyboards. */
static const uint8_t IDLE_RATE = 0;

/** Delay before a pressed key starts auto-repeating. */
static const unsigned int DEFAULT_DELAY_BEFORE_FIRST_REPEAT = 500 * 1000;

/** Delay between two repeats of a pressed key when auto-repeating. */
static const unsigned int DEFAULT_REPEAT_DELAY = 50 * 1000;

/*----------------------------------------------------------------------------*/

/** Keyboard polling endpoint description for boot protocol class. */
const usb_endpoint_description_t usb_hid_kbd_poll_endpoint_description = {
        .transfer_type = USB_TRANSFER_INTERRUPT,
        .direction = USB_DIRECTION_IN,
        .interface_class = USB_CLASS_HID,
        .interface_subclass = USB_HID_SUBCLASS_BOOT,
        .interface_protocol = USB_HID_PROTOCOL_KEYBOARD,
        .flags = 0
};

const char *HID_KBD_FUN_NAME = "keyboard";
const char *HID_KBD_CATEGORY_NAME = "keyboard";

static void usb_kbd_set_led(usb_hid_dev_t *hid_dev, usb_kbd_t *kbd_dev);

/*----------------------------------------------------------------------------*/

enum {
        USB_KBD_BOOT_REPORT_DESCRIPTOR_SIZE = 63
};

static const uint8_t USB_KBD_BOOT_REPORT_DESCRIPTOR[
    USB_KBD_BOOT_REPORT_DESCRIPTOR_SIZE] = {
        0x05, 0x01,  // Usage Page (Generic Desktop),
        0x09, 0x06,  // Usage (Keyboard),
        0xA1, 0x01,  // Collection (Application),
        0x75, 0x01,  //   Report Size (1),
        0x95, 0x08,  //   Report Count (8),       
        0x05, 0x07,  //   Usage Page (Key Codes);
        0x19, 0xE0,  //   Usage Minimum (224),
        0x29, 0xE7,  //   Usage Maximum (231),
        0x15, 0x00,  //   Logical Minimum (0),
        0x25, 0x01,  //   Logical Maximum (1),
        0x81, 0x02,  //   Input (Data, Variable, Absolute),   ; Modifier byte
        0x95, 0x01,  //   Report Count (1),
        0x75, 0x08,  //   Report Size (8),
        0x81, 0x01,  //   Input (Constant),                   ; Reserved byte
        0x95, 0x05,  //   Report Count (5),
        0x75, 0x01,  //   Report Size (1),
        0x05, 0x08,  //   Usage Page (Page# for LEDs),
        0x19, 0x01,  //   Usage Minimum (1),
        0x29, 0x05,  //   Usage Maxmimum (5),
        0x91, 0x02,  //   Output (Data, Variable, Absolute),  ; LED report
        0x95, 0x01,  //   Report Count (1),
        0x75, 0x03,  //   Report Size (3),
        0x91, 0x01,  //   Output (Constant),              ; LED report padding
        0x95, 0x06,  //   Report Count (6),
        0x75, 0x08,  //   Report Size (8),
        0x15, 0x00,  //   Logical Minimum (0),
        0x25, 0xff,  //   Logical Maximum (255),
        0x05, 0x07,  //   Usage Page (Key Codes),
        0x19, 0x00,  //   Usage Minimum (0),
        0x29, 0xff,  //   Usage Maximum (255),
        0x81, 0x00,  //   Input (Data, Array),            ; Key arrays (6 bytes)
        0xC0           // End Collection

};

/*----------------------------------------------------------------------------*/

typedef enum usb_kbd_flags {
        USB_KBD_STATUS_UNINITIALIZED = 0,
        USB_KBD_STATUS_INITIALIZED = 1,
        USB_KBD_STATUS_TO_DESTROY = -1
} usb_kbd_flags;

/*----------------------------------------------------------------------------*/
/* IPC method handler                                                         */
/*----------------------------------------------------------------------------*/

static void default_connection_handler(ddf_fun_t *, ipc_callid_t, ipc_call_t *);

/**
 * Default handler for IPC methods not handled by DDF.
 *
 * Currently recognizes only one method (IPC_M_CONNECT_TO_ME), in which case it
 * assumes the caller is the console and thus it stores IPC session to it for
 * later use by the driver to notify about key events.
 *
 * @param fun Device function handling the call.
 * @param icallid Call id.
 * @param icall Call data.
 */
static void default_connection_handler(ddf_fun_t *fun,
    ipc_callid_t icallid, ipc_call_t *icall)
{
        sysarg_t method = IPC_GET_IMETHOD(*icall);

        usb_kbd_t *kbd_dev = (usb_kbd_t *) fun->driver_data;
        if (kbd_dev == NULL) {
                usb_log_debug("default_connection_handler: "
                    "Missing parameter.\n");
                async_answer_0(icallid, EINVAL);
                return;
        }

        async_sess_t *sess =
            async_callback_receive_start(EXCHANGE_SERIALIZE, icall);
        if (sess != NULL) {
                if (kbd_dev->console_sess == NULL) {
                        kbd_dev->console_sess = sess;
                        usb_log_debug("default_connection_handler: OK\n");
                        async_answer_0(icallid, EOK);
                } else {
                        usb_log_debug("default_connection_handler: "
                            "console session already set\n");
                        async_answer_0(icallid, ELIMIT);
                }
        } else {
                switch (method) {
                case KBDEV_SET_IND:
                        kbd_dev->mods = IPC_GET_ARG1(*icall);
                        usb_kbd_set_led(kbd_dev->hid_dev, kbd_dev);
                        async_answer_0(icallid, EOK);
                        break;
                default:
                        usb_log_debug("default_connection_handler: Wrong function.\n");
                        async_answer_0(icallid, EINVAL);
                        break;
                }
        }
}

/*----------------------------------------------------------------------------*/
/* Key processing functions                                                   */
/*----------------------------------------------------------------------------*/
/**
 * Handles turning of LED lights on and off.
 *
 * As with most other keyboards, the LED indicators in USB keyboards are
 * driven by software. When state of some modifier changes, the input server
 * will call us and tell us to update the LED state and what the new state
 * should be.
 *
 * This functions sets the LED lights according to current settings of modifiers
 * kept in the keyboard device structure.
 *
 * @param kbd_dev Keyboard device structure.
 */
static void usb_kbd_set_led(usb_hid_dev_t *hid_dev, usb_kbd_t *kbd_dev) 
{
        if (kbd_dev->output_size == 0) {
                return;
        }

        /* Reset the LED data. */
        memset(kbd_dev->led_data, 0, kbd_dev->led_output_size * sizeof(int32_t));
        usb_log_debug("Creating output report:\n");

        usb_hid_report_field_t *field = usb_hid_report_get_sibling(
            &hid_dev->report, NULL, kbd_dev->led_path,
            USB_HID_PATH_COMPARE_END | USB_HID_PATH_COMPARE_USAGE_PAGE_ONLY,
            USB_HID_REPORT_TYPE_OUTPUT);

        while (field != NULL) {

                if ((field->usage == USB_HID_LED_NUM_LOCK)
                    && (kbd_dev->mods & KM_NUM_LOCK)){
                        field->value = 1;
                }

                if ((field->usage == USB_HID_LED_CAPS_LOCK)
                    && (kbd_dev->mods & KM_CAPS_LOCK)){
                        field->value = 1;
                }

                if ((field->usage == USB_HID_LED_SCROLL_LOCK)
                    && (kbd_dev->mods & KM_SCROLL_LOCK)){
                        field->value = 1;
                }

                field = usb_hid_report_get_sibling(
                    &hid_dev->report, field, kbd_dev->led_path,
                USB_HID_PATH_COMPARE_END | USB_HID_PATH_COMPARE_USAGE_PAGE_ONLY,
                    USB_HID_REPORT_TYPE_OUTPUT);
        }

        // TODO: what about the Report ID?
        int rc = usb_hid_report_output_translate(&hid_dev->report, 0,
            kbd_dev->output_buffer, kbd_dev->output_size);

        if (rc != EOK) {
                usb_log_warning("Error translating LED output to output report"
                    ".\n");
                return;
        }

        usb_log_debug("Output report buffer: %s\n", 
            usb_debug_str_buffer(kbd_dev->output_buffer, kbd_dev->output_size, 
                0));

        usbhid_req_set_report(&hid_dev->usb_dev->ctrl_pipe, 
            hid_dev->usb_dev->interface_no, USB_HID_REPORT_TYPE_OUTPUT, 
            kbd_dev->output_buffer, kbd_dev->output_size);
}

/*----------------------------------------------------------------------------*/
/** Send key event.
 *
 * @param kbd_dev Keyboard device structure.
 * @param type Type of the event (press / release). Recognized values:
 *             KEY_PRESS, KEY_RELEASE
 * @param key Key code
 */
void usb_kbd_push_ev(usb_hid_dev_t *hid_dev, usb_kbd_t *kbd_dev, int type, 
    unsigned int key)
{
        usb_log_debug2("Sending kbdev event %d/%d to the console\n", type, key);
        if (kbd_dev->console_sess == NULL) {
                usb_log_warning(
                    "Connection to console not ready, key discarded.\n");
                return;
        }

        async_exch_t *exch = async_exchange_begin(kbd_dev->console_sess);
        async_msg_2(exch, KBDEV_EVENT, type, key);
        async_exchange_end(exch);
}

/*----------------------------------------------------------------------------*/

static inline int usb_kbd_is_lock(unsigned int key_code) 
{
        return (key_code == KC_NUM_LOCK
            || key_code == KC_SCROLL_LOCK
            || key_code == KC_CAPS_LOCK);
}

static size_t find_in_array_int32(int32_t val, int32_t *arr, size_t arr_size)
{
        for (size_t i = 0; i < arr_size; i++) {
                if (arr[i] == val) {
                        return i;
                }
        }

        return (size_t) -1;
}

/*----------------------------------------------------------------------------*/
/**
 * Checks if some keys were pressed or released and generates key events.
 *
 * An event is created only when key is pressed or released. Besides handling
 * the events (usb_kbd_push_ev()), the auto-repeat fibril is notified about
 * key presses and releases (see usb_kbd_repeat_start() and 
 * usb_kbd_repeat_stop()).
 *
 * @param kbd_dev Keyboard device structure.
 * @param key_codes Parsed keyboard report - codes of currently pressed keys 
 *                  according to HID Usage Tables.
 * @param count Number of key codes in report (size of the report).
 *
 * @sa usb_kbd_push_ev(), usb_kbd_repeat_start(), usb_kbd_repeat_stop()
 */
static void usb_kbd_check_key_changes(usb_hid_dev_t *hid_dev, 
    usb_kbd_t *kbd_dev)
{
        unsigned int key;
        size_t i;

        /*
         * First of all, check if the kbd have reported phantom state.
         *
         * As there is no way to distinguish keys from modifiers, we do not have
         * a way to check that 'all keys report Error Rollover'. We thus check
         * if there is at least one such error and in such case we ignore the
         * whole input report.
         */
        i = find_in_array_int32(ERROR_ROLLOVER, kbd_dev->keys,
            kbd_dev->key_count);
        if (i != (size_t) -1) {
                usb_log_debug("Detected phantom state.\n");
                return;
        }

        /*
         * Key releases
         */
        for (i = 0; i < kbd_dev->key_count; i++) {
                int32_t old_key = kbd_dev->keys_old[i];
                /* Find the old key among currently pressed keys. */
                size_t pos = find_in_array_int32(old_key, kbd_dev->keys,
                    kbd_dev->key_count);
                /* If the key was not found, we need to signal release. */
                if (pos == (size_t) -1) {
                        key = usbhid_parse_scancode(old_key);
                        if (!usb_kbd_is_lock(key)) {
                                usb_kbd_repeat_stop(kbd_dev, key);
                        }
                        usb_kbd_push_ev(hid_dev, kbd_dev, KEY_RELEASE, key);
                        usb_log_debug2("Key released: %u "
                            "(USB code %" PRIu32 ")\n", key, old_key);
                }
        }

        /*
         * Key presses
         */
        for (i = 0; i < kbd_dev->key_count; ++i) {
                int32_t new_key = kbd_dev->keys[i];
                /* Find the new key among already pressed keys. */
                size_t pos = find_in_array_int32(new_key, kbd_dev->keys_old,
                    kbd_dev->key_count);
                /* If the key was not found, we need to signal press. */
                if (pos == (size_t) -1) {
                        key = usbhid_parse_scancode(kbd_dev->keys[i]);
                        if (!usb_kbd_is_lock(key)) {
                                usb_kbd_repeat_start(kbd_dev, key);
                        }
                        usb_kbd_push_ev(hid_dev, kbd_dev, KEY_PRESS, key);
                        usb_log_debug2("Key pressed: %u "
                            "(USB code %" PRIu32 ")\n", key, new_key);
                }
        }

        memcpy(kbd_dev->keys_old, kbd_dev->keys, kbd_dev->key_count * 4);

        char key_buffer[512];
        ddf_dump_buffer(key_buffer, 512,
            kbd_dev->keys_old, 4, kbd_dev->key_count, 0);
        usb_log_debug2("Stored keys %s.\n", key_buffer);
}

/*----------------------------------------------------------------------------*/
/* General kbd functions                                                      */
/*----------------------------------------------------------------------------*/
/**
 * Processes data received from the device in form of report.
 *
 * This function uses the HID report parser to translate the data received from
 * the device into generic USB HID key codes and into generic modifiers bitmap.
 * The parser then calls the given callback (usb_kbd_process_keycodes()).
 *
 * @note Currently, only the boot protocol is supported.
 *
 * @param kbd_dev Keyboard device structure (must be initialized).
 * @param buffer Data from the keyboard (i.e. the report).
 * @param actual_size Size of the data from keyboard (report size) in bytes.
 *
 * @sa usb_kbd_process_keycodes(), usb_hid_boot_keyboard_input_report(),
 *     usb_hid_parse_report().
 */
static void usb_kbd_process_data(usb_hid_dev_t *hid_dev, usb_kbd_t *kbd_dev)
{
        assert(hid_dev != NULL);
        assert(kbd_dev != NULL);

        usb_hid_report_path_t *path = usb_hid_report_path();
        usb_hid_report_path_append_item(path, USB_HIDUT_PAGE_KEYBOARD, 0);

        usb_hid_report_path_set_report_id (path, hid_dev->report_id);

        // fill in the currently pressed keys

        usb_hid_report_field_t *field = usb_hid_report_get_sibling(
            &hid_dev->report, NULL, path,
            USB_HID_PATH_COMPARE_END | USB_HID_PATH_COMPARE_USAGE_PAGE_ONLY,
            USB_HID_REPORT_TYPE_INPUT);
        unsigned i = 0;

        while (field != NULL) {
                usb_log_debug2("FIELD (%p) - VALUE(%d) USAGE(%u)\n", 
                    field, field->value, field->usage);
                
                assert(i < kbd_dev->key_count);

                // save the key usage
                if (field->value != 0) {
                        kbd_dev->keys[i] = field->usage;
                }
                else {
                        kbd_dev->keys[i] = 0;
                }
                usb_log_debug2("Saved %u. key usage %d\n", i, kbd_dev->keys[i]);

                ++i;
                field = usb_hid_report_get_sibling(
                    &hid_dev->report, field, path, USB_HID_PATH_COMPARE_END
                        | USB_HID_PATH_COMPARE_USAGE_PAGE_ONLY,
                    USB_HID_REPORT_TYPE_INPUT);
        }

        usb_hid_report_path_free(path);

        usb_kbd_check_key_changes(hid_dev, kbd_dev);
}

/*----------------------------------------------------------------------------*/
/* HID/KBD structure manipulation                                             */
/*----------------------------------------------------------------------------*/

static void usb_kbd_mark_unusable(usb_kbd_t *kbd_dev)
{
        kbd_dev->initialized = USB_KBD_STATUS_TO_DESTROY;
}

/*----------------------------------------------------------------------------*/

/**
 * Creates a new USB/HID keyboard structure.
 *
 * The structure returned by this function is not initialized. Use 
 * usb_kbd_init() to initialize it prior to polling.
 *
 * @return New uninitialized structure for representing a USB/HID keyboard or
 *         NULL if not successful (memory error).
 */
static usb_kbd_t *usb_kbd_new(void)
{
        usb_kbd_t *kbd_dev = 
            (usb_kbd_t *)calloc(1, sizeof(usb_kbd_t));

        if (kbd_dev == NULL) {
                usb_log_error("No memory!\n");
                return NULL;
        }

        kbd_dev->console_sess = NULL;
        kbd_dev->initialized = USB_KBD_STATUS_UNINITIALIZED;

        return kbd_dev;
}

/*----------------------------------------------------------------------------*/

static int usb_kbd_create_function(usb_kbd_t *kbd_dev)
{
        assert(kbd_dev != NULL);
        assert(kbd_dev->hid_dev != NULL);
        assert(kbd_dev->hid_dev->usb_dev != NULL);

        /* Create the exposed function. */
        usb_log_debug("Creating DDF function %s...\n", HID_KBD_FUN_NAME);
        ddf_fun_t *fun = ddf_fun_create(kbd_dev->hid_dev->usb_dev->ddf_dev,
            fun_exposed, HID_KBD_FUN_NAME);
        if (fun == NULL) {
                usb_log_error("Could not create DDF function node.\n");
                return ENOMEM;
        }

        /*
         * Store the initialized HID device and HID ops
         * to the DDF function.
         */
        fun->ops = &kbd_dev->ops;
        fun->driver_data = kbd_dev;

        int rc = ddf_fun_bind(fun);
        if (rc != EOK) {
                usb_log_error("Could not bind DDF function: %s.\n",
                    str_error(rc));
                fun->driver_data = NULL; /* We need this later */
                ddf_fun_destroy(fun);
                return rc;
        }

        usb_log_debug("%s function created. Handle: %" PRIun "\n",
            HID_KBD_FUN_NAME, fun->handle);

        usb_log_debug("Adding DDF function to category %s...\n", 
            HID_KBD_CLASS_NAME);
        rc = ddf_fun_add_to_category(fun, HID_KBD_CATEGORY_NAME);
        if (rc != EOK) {
                usb_log_error(
                    "Could not add DDF function to category %s: %s.\n",
                    HID_KBD_CLASS_NAME, str_error(rc));
                fun->driver_data = NULL; /* We need this later */
                ddf_fun_destroy(fun);
                return rc;
        }
        kbd_dev->fun = fun;

        return EOK;
}

/*----------------------------------------------------------------------------*/
/* API functions                                                              */
/*----------------------------------------------------------------------------*/
/**
 * Initialization of the USB/HID keyboard structure.
 *
 * This functions initializes required structures from the device's descriptors.
 *
 * During initialization, the keyboard is switched into boot protocol, the idle
 * rate is set to 0 (infinity), resulting in the keyboard only reporting event
 * when a key is pressed or released. Finally, the LED lights are turned on 
 * according to the default setup of lock keys.
 *
 * @note By default, the keyboards is initialized with Num Lock turned on and 
 *       other locks turned off.
 *
 * @param kbd_dev Keyboard device structure to be initialized.
 * @param dev DDF device structure of the keyboard.
 *
 * @retval EOK if successful.
 * @retval EINVAL if some parameter is not given.
 * @return Other value inherited from function usbhid_dev_init().
 */
int usb_kbd_init(usb_hid_dev_t *hid_dev, void **data)
{
        usb_log_debug("Initializing HID/KBD structure...\n");

        if (hid_dev == NULL) {
                usb_log_error("Failed to init keyboard structure: no structure"
                    " given.\n");
                return EINVAL;
        }

        usb_kbd_t *kbd_dev = usb_kbd_new();
        if (kbd_dev == NULL) {
                usb_log_error("Error while creating USB/HID KBD device "
                    "structure.\n");
                return ENOMEM;  // TODO: some other code??
        }

        /* Store link to HID device */
        kbd_dev->hid_dev = hid_dev;

        /*
         * TODO: make more general
         */
        usb_hid_report_path_t *path = usb_hid_report_path();
        usb_hid_report_path_append_item(path, USB_HIDUT_PAGE_KEYBOARD, 0);

        usb_hid_report_path_set_report_id(path, 0);

        kbd_dev->key_count = usb_hid_report_size(
            &hid_dev->report, 0, USB_HID_REPORT_TYPE_INPUT);
        usb_hid_report_path_free(path);

        usb_log_debug("Size of the input report: %zu\n", kbd_dev->key_count);

        kbd_dev->keys = calloc(kbd_dev->key_count, sizeof(int32_t));

        if (kbd_dev->keys == NULL) {
                usb_log_error("No memory!\n");
                free(kbd_dev);
                return ENOMEM;
        }

        kbd_dev->keys_old = 
                (int32_t *)calloc(kbd_dev->key_count, sizeof(int32_t));

        if (kbd_dev->keys_old == NULL) {
                usb_log_error("No memory!\n");
                free(kbd_dev->keys);
                free(kbd_dev);
                return ENOMEM;
        }

        /*
         * Output report
         */
        kbd_dev->output_size = 0;
        kbd_dev->output_buffer = usb_hid_report_output(&hid_dev->report,
            &kbd_dev->output_size, 0);
        if (kbd_dev->output_buffer == NULL) {
                usb_log_warning("Error creating output report buffer.\n");
                free(kbd_dev->keys);
                return ENOMEM;
        }

        usb_log_debug("Output buffer size: %zu\n", kbd_dev->output_size);

        kbd_dev->led_path = usb_hid_report_path();
        usb_hid_report_path_append_item(
            kbd_dev->led_path, USB_HIDUT_PAGE_LED, 0);

        kbd_dev->led_output_size = usb_hid_report_size(
            &hid_dev->report, 0, USB_HID_REPORT_TYPE_OUTPUT);

        usb_log_debug("Output report size (in items): %zu\n", 
            kbd_dev->led_output_size);

        kbd_dev->led_data = (int32_t *)calloc(
            kbd_dev->led_output_size, sizeof(int32_t));

        if (kbd_dev->led_data == NULL) {
                usb_log_warning("Error creating buffer for LED output report."
                    "\n");
                free(kbd_dev->keys);
                usb_hid_report_output_free(kbd_dev->output_buffer);
                free(kbd_dev);
                return ENOMEM;
        }

        /*
         * Modifiers and locks
         */
        kbd_dev->modifiers = 0;
        kbd_dev->mods = DEFAULT_ACTIVE_MODS;
        kbd_dev->lock_keys = 0;

        /*
         * Autorepeat
         */
        kbd_dev->repeat.key_new = 0;
        kbd_dev->repeat.key_repeated = 0;
        kbd_dev->repeat.delay_before = DEFAULT_DELAY_BEFORE_FIRST_REPEAT;
        kbd_dev->repeat.delay_between = DEFAULT_REPEAT_DELAY;

        fibril_mutex_initialize(&kbd_dev->repeat_mtx);

        // save the KBD device structure into the HID device structure
        *data = kbd_dev;

        // set handler for incoming calls
        kbd_dev->ops.default_handler = default_connection_handler;

        /*
         * Set LEDs according to initial setup.
         * Set Idle rate
         */
        usb_kbd_set_led(hid_dev, kbd_dev);

        usbhid_req_set_idle(&hid_dev->usb_dev->ctrl_pipe, 
            hid_dev->usb_dev->interface_no, IDLE_RATE);

        /*
         * Create new fibril for auto-repeat
         */
        fid_t fid = fibril_create(usb_kbd_repeat_fibril, kbd_dev);
        if (fid == 0) {
                usb_log_error("Failed to start fibril for KBD auto-repeat");
                return ENOMEM;
        }
        fibril_add_ready(fid);

        kbd_dev->initialized = USB_KBD_STATUS_INITIALIZED;
        usb_log_debug("HID/KBD device structure initialized.\n");

        usb_log_debug("Creating KBD function...\n");
        int rc = usb_kbd_create_function(kbd_dev);
        if (rc != EOK) {
                usb_kbd_destroy(kbd_dev);
                return rc;
        }

        return EOK;
}

/*----------------------------------------------------------------------------*/

bool usb_kbd_polling_callback(usb_hid_dev_t *hid_dev, void *data)
{
        if (hid_dev == NULL/* || buffer == NULL*/ || data == NULL) {
                // do not continue polling (???)
                return false;
        }

        usb_kbd_t *kbd_dev = (usb_kbd_t *)data;
        assert(kbd_dev != NULL);

        // TODO: add return value from this function
        usb_kbd_process_data(hid_dev, kbd_dev);

        return true;
}

/*----------------------------------------------------------------------------*/

int usb_kbd_is_initialized(const usb_kbd_t *kbd_dev)
{
        return (kbd_dev->initialized == USB_KBD_STATUS_INITIALIZED);
}

/*----------------------------------------------------------------------------*/

int usb_kbd_is_ready_to_destroy(const usb_kbd_t *kbd_dev)
{
        return (kbd_dev->initialized == USB_KBD_STATUS_TO_DESTROY);
}

/*----------------------------------------------------------------------------*/
/**
 * Properly destroys the USB/HID keyboard structure.
 *
 * @param kbd_dev Pointer to the structure to be destroyed.
 */
void usb_kbd_destroy(usb_kbd_t *kbd_dev)
{
        if (kbd_dev == NULL) {
                return;
        }

        // hangup session to the console
        async_hangup(kbd_dev->console_sess);

        //assert(!fibril_mutex_is_locked((*kbd_dev)->repeat_mtx));
        // FIXME - the fibril_mutex_is_locked may not cause
        // fibril scheduling
        while (fibril_mutex_is_locked(&kbd_dev->repeat_mtx)) {}

        // free all buffers
        free(kbd_dev->keys);
        free(kbd_dev->keys_old);
        free(kbd_dev->led_data);

        if (kbd_dev->led_path != NULL) {
                usb_hid_report_path_free(kbd_dev->led_path);
        }
        if (kbd_dev->output_buffer != NULL) {
                usb_hid_report_output_free(kbd_dev->output_buffer);
        }

        if (ddf_fun_unbind(kbd_dev->fun) != EOK) {
                usb_log_warning("Failed to unbind kbd function.\n");
        } else {
                usb_log_debug2("%s unbound.\n", kbd_dev->fun->name);
                kbd_dev->fun->driver_data = NULL;
                ddf_fun_destroy(kbd_dev->fun);
        }
}

/*----------------------------------------------------------------------------*/

void usb_kbd_deinit(usb_hid_dev_t *hid_dev, void *data)
{
        if (hid_dev == NULL) {
                return;
        }

        if (data != NULL) {
                usb_kbd_t *kbd_dev = data;
                if (usb_kbd_is_initialized(kbd_dev)) {
                        usb_kbd_mark_unusable(kbd_dev);
                        /* wait for autorepeat */
                        async_usleep(CHECK_DELAY);
                        usb_kbd_destroy(kbd_dev);
                }
        }
}

/*----------------------------------------------------------------------------*/

int usb_kbd_set_boot_protocol(usb_hid_dev_t *hid_dev)
{
        int rc = usb_hid_parse_report_descriptor(
            &hid_dev->report, USB_KBD_BOOT_REPORT_DESCRIPTOR,
            USB_KBD_BOOT_REPORT_DESCRIPTOR_SIZE);

        if (rc != EOK) {
                usb_log_error("Failed to parse boot report descriptor: %s\n",
                    str_error(rc));
                return rc;
        }

        rc = usbhid_req_set_protocol(&hid_dev->usb_dev->ctrl_pipe,
            hid_dev->usb_dev->interface_no, USB_HID_PROTOCOL_BOOT);

        if (rc != EOK) {
                usb_log_warning("Failed to set boot protocol to the device: "
                    "%s\n", str_error(rc));
                return rc;
        }

        return EOK;
}

/**
 * @}
 */