/*
 * Copyright (c) 2009 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 <arch/drivers/kbd.h>
#include <genarch/kbd/key.h>
#include <genarch/kbd/scanc.h>
#include <genarch/kbd/scanc_pc.h>
#include <genarch/drivers/legacy/ia32/io.h>
#include <cpu.h>
#include <arch/asm.h>
#include <arch.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,
};

static irq_ownership_t i8042_claim(irq_t *irq)
{
	i8042_instance_t *i8042_instance = irq->instance;
	i8042_t *dev = i8042_instance->i8042;
	if (pio_read_8(&dev->status) & i8042_BUFFER_FULL_MASK)
		return IRQ_ACCEPT;
	else
		return IRQ_DECLINE;
}

static void i8042_irq_handler(irq_t *irq)
{
	i8042_instance_t *instance = irq->instance;
	i8042_t *dev = instance->i8042;

	uint8_t data;
	uint8_t status;
		
	if (((status = pio_read_8(&dev->status)) & i8042_BUFFER_FULL_MASK)) {
		data = pio_read_8(&dev->data);
			
		if ((status & i8042_MOUSE_DATA))
			return;

		if (data & KEY_RELEASE)
			key_released(data ^ KEY_RELEASE);
		else
			key_pressed(data);
	}
}

/** Initialize i8042. */
bool
i8042_init(i8042_t *dev, devno_t devno, inr_t inr)
{
	i8042_instance_t *instance;

	chardev_initialize("i8042_kbd", &kbrd, &ops);
	stdin = &kbrd;
	
	instance = malloc(sizeof(i8042_instance_t), FRAME_ATOMIC);
	if (!instance)
		return false;
	
	instance->devno = devno;
	instance->i8042 = dev;
	
	irq_initialize(&instance->irq);
	instance->irq.devno = devno;
	instance->irq.inr = inr;
	instance->irq.claim = i8042_claim;
	instance->irq.handler = i8042_irq_handler;
	instance->irq.instance = instance;
	irq_register(&instance->irq);
	
	trap_virtual_enable_irqs(1 << inr);
	
	/*
	 * Clear input buffer.
	 */
	while (pio_read_8(&dev->status) & i8042_BUFFER_FULL_MASK)
		(void) pio_read_8(&dev->data);
	
	return true;
}

/* Called from getc(). */
void i8042_resume(chardev_t *d)
{
}

/* Called from getc(). */
void i8042_suspend(chardev_t *d)
{
}

/** @}
 */