/*
 * Copyright 2011-2012 Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *      Alexander von Gluck, kallisti5@unixzen.com
 */


#include "gpio.h"


#if 0
#define GPIO_IN(g) *(GPIO_BASE + ((g) / 10)) &= ~(7 << (((g) % 10) * 3))
#define GPIO_OUT(g) *(GPIO_BASE + ((g) / 10)) |= (1 << (((g) % 10) * 3))
#define GPIO_SET(g) *(GPIO_BASE + 7) = (1 << g)
#define GPIO_CLR(g) *(GPIO_BASE + 10) = (1 << g)

#define GPIO_ALT(g, a) *(GPIO_BASE + (((g) / 10))) \
    |= (((a) <= 3 ? (a) + 4 : (a) == 4 ? 3 : 2) << (((g)%10) * 3))
#endif


/*!
 * At GPIO (base) (pin) directon to input
 */
void
gpio_in(addr_t base, int pin)
{
    *(volatile unsigned char *)(base + (pin / 10))
        &= ~(7 << ((pin % 10) * 3));
}


/*!
 * At GPIO (base) (pin) directon to output
 */
void
gpio_out(addr_t base, int pin)
{
    *(volatile unsigned char *)(base + (pin / 10))
        |= (1 << ((pin % 10) * 3));
}



/*!
 * At GPIO (base) (pin) state set (high)
 */
void
gpio_set(addr_t base, int pin)
{
    *(volatile unsigned char *)(base + 7) = (1 << pin);
}


/*!
 * At GPIO (base) (pin) state clear (low)
 */
void
gpio_clear(addr_t base, int pin)
{
    *(volatile unsigned char *)(base + 10) = (1 << pin);
}



/*!
 * At GPIO (base) (pin) alternate function (value)
 */
void
gpio_alt(addr_t base, int pin, int value)
{
    *(volatile unsigned char *)(base + (pin / 10))
        |= ((value <= 3 ? value + 4 : value == 4 ? 3 : 2) << ((pin % 10) * 3));

}


void
gpio_init()
{
    // ** Take control of ok uart, led, and general use pins
    int pin = 0;
    for (pin = 14; pin <= 25; pin++) {
        gpio_in(GPIO_BASE, pin);
        gpio_out(GPIO_BASE, pin);
    }

    // ** Prepare UART pins for serial communication
    // Set alternate function 0 on UART pins
    gpio_alt(GPIO_BASE, 14, 4);
    gpio_alt(GPIO_BASE, 15, 4);
    // Pull UART pins to initial state low
    gpio_clear(GPIO_BASE, 14);
    gpio_clear(GPIO_BASE, 15);
}