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/*

 * Copyright (C) 2001-2004 Jakub Jermar

 * 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 genarch

 * @{

 */

/**

 * @file

 * @brief   i8042 processor driver.

 *

 * It takes care of low-level keyboard functions.

 */

#include <genarch/kbd/i8042.h>

#include <genarch/kbd/key.h>

#include <genarch/kbd/scanc.h>

#include <genarch/kbd/scanc_pc.h>

#include <arch/drivers/i8042.h>

#include <arch/interrupt.h>

#include <cpu.h>

#include <arch/asm.h>

#include <arch.h>

#include <typedefs.h>

#include <console/chardev.h>

#include <console/console.h>

#include <interrupt.h>

/* Keyboard commands. */

#define KBD_ENABLE  0xf4

#define KBD_DISABLE 0xf5

#define KBD_ACK     0xfa

/*

 * 60  Write 8042 Command Byte: next data byte written to port 60h is

 *     placed in 8042 command register. Format:

 *

 *    |7|6|5|4|3|2|1|0|8042 Command Byte

 *     | | | | | | | `---- 1=enable output register full interrupt

 *     | | | | | | `----- should be 0

 *     | | | | | `------ 1=set status register system, 0=clear

 *     | | | | `------- 1=override keyboard inhibit, 0=allow inhibit

 *     | | | `-------- disable keyboard I/O by driving clock line low

 *     | | `--------- disable auxiliary device, drives clock line low

 *     | `---------- IBM scancode translation 0=AT, 1=PC/XT

 *     `----------- reserved, should be 0

 */

#define i8042_SET_COMMAND   0x60

#define i8042_COMMAND       0x69

#define i8042_BUFFER_FULL_MASK  0x01

#define i8042_WAIT_MASK     0x02

#define i8042_MOUSE_DATA        0x20

static void i8042_suspend(chardev_t *);

static void i8042_resume(chardev_t *);

chardev_t kbrd;

static chardev_operations_t ops = {

    .suspend = i8042_suspend,

    .resume = i8042_resume,

    .read = key_read

};

static void i8042_interrupt(int n, istate_t *istate);

static void i8042_wait(void);

static iroutine oldvector;

/** Initialize keyboard and service interrupts using kernel routine */

void i8042_grab(void)

{

    oldvector = exc_register(VECTOR_KBD, "i8042_interrupt", (iroutine) i8042_interrupt);

    i8042_wait();

    i8042_command_write(i8042_SET_COMMAND);

    i8042_wait();

    i8042_data_write(i8042_COMMAND);

    i8042_wait();

}

/** Resume the former interrupt vector */

void i8042_release(void)

{

    if (oldvector)

        exc_register(VECTOR_KBD, "user_interrupt", oldvector);

}

/** Initialize i8042. */

void i8042_init(void)

{

    int i;

    i8042_grab();

        /* Prevent user from accidentaly releasing calling i8042_resume

     * and disabling keyboard

     */

    oldvector = NULL;

    trap_virtual_enable_irqs(1<<IRQ_KBD);

    chardev_initialize("i8042_kbd", &kbrd, &ops);

    stdin = &kbrd;

    /*

     * Clear input buffer.

     * Number of iterations is limited to prevent infinite looping.

     */

    for (i = 0; (i8042_status_read() & i8042_BUFFER_FULL_MASK) && i < 100; i++) {

        i8042_data_read();

    }  

}

/** Process i8042 interrupt.

 *

 * @param n Interrupt vector.

 * @param istate Interrupted state.

 */

void i8042_interrupt(int n, istate_t *istate)

{

    uint8_t x;

    uint8_t status;

    while (((status=i8042_status_read()) & i8042_BUFFER_FULL_MASK)) {

        x = i8042_data_read();

        if ((status & i8042_MOUSE_DATA))

            continue;

        if (x & KEY_RELEASE)

            key_released(x ^ KEY_RELEASE);

        else

            key_pressed(x);

    }

    trap_virtual_eoi();

}

/** Wait until the controller reads its data. */

void i8042_wait(void) {

    while (i8042_status_read() & i8042_WAIT_MASK) {

        /* wait */

    }

}

/* Called from getc(). */

void i8042_resume(chardev_t *d)

{

}

/* Called from getc(). */

void i8042_suspend(chardev_t *d)

{

}

char key_read(chardev_t *d)

{

    char ch;   

    while(!(ch = active_read_buff_read())) {

        uint8_t x;

        while (!(i8042_status_read() & i8042_BUFFER_FULL_MASK))

            ;

        x = i8042_data_read();

        if (x & KEY_RELEASE)

            key_released(x ^ KEY_RELEASE);

        else

            active_read_key_pressed(x);

    }

    return ch;

}

/** Poll for key press and release events.

 *

 * This function can be used to implement keyboard polling.

 */

void i8042_poll(void)

{

    uint8_t x;

    while (((x = i8042_status_read() & i8042_BUFFER_FULL_MASK))) {

        x = i8042_data_read();

        if (x & KEY_RELEASE)

            key_released(x ^ KEY_RELEASE);

        else

            key_pressed(x);

    }

}

/** @}

 */