source: mainline/kernel/genarch/src/kbd/i8042.c@ 2b017ba

/*
 * 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 *);

static chardev_operations_t ops = {
        .suspend = i8042_suspend,
        .resume = i8042_resume,
        .read = i8042_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 i8042_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);
        }
}

/** @}
 */