/*
 *  EP9302 Digital library
 *  Copyright (C) 2010  Andrea Milazzo aka Mancausoft
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <unistd.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <assert.h>
#include <stdint.h>
#include <stdbool.h>
#include "digital.h"



/* globals */
static unsigned long data_page, syscon_page;

static volatile uint8_t* port[8], *portd[8];


/**
 * Set a bit of HW Port.
 * \param nport The HW port to set. The value must be betwen 0 and 7.
 * \param value The value of bit to set.
 * \param pos The position of bit to set.
 * \return The value returned is -1 if the param nport is incorrect.
 *  Otherwise return 0.
 */
int set_port_bit (uint8_t nport, bool value, uint8_t pos)
{
	if(nport < 8 && pos < 8)
	{
		set_bit(value, port[nport], pos);
		return 0;
	}
	return -1;
}

/**
 * Get a bit of HW Port.
 * \param nport The HW port to get. The value must be betwen 0 and 7.
 * \param value The pointer to the return value.
 * \param pos The position of bit to get.
 * \return The value returned is -1 if the param nport is incorrect.
 *  Otherwise return 0.
 */
int get_port_bit (uint8_t nport, bool* value, uint8_t pos)
{
	if(nport < 8 && pos < 8)
	{
		get_bit(*port[nport], value, pos);
		return 0;
	}
	return -1;
}

/**
 * Set direction bit of HW Port.
 * \param nport The HW port to set. The value must be betwen 0 and 7.
 * \param value The value of direction bit to set.
 * \param pos The position of direction bit to set.
 * \return The value returned is -1 if the param nport is incorrect.
 *  Otherwise return 0.
 */
int set_port_dir_bit (uint8_t nport, bool value, uint8_t pos)
{
	if(nport < 8 && pos < 8)
	{
		set_bit(value, portd[nport], pos);
		return 0;
	}
	return -1;
}

/**
 * Get direction bit of HW Port.
 * \param nport The HW port to get. The value must be betwen 0 and 7.
 * \param value The pointer to the return value.
 * \param pos The position of direction bit to get.
 * \return The value returned is -1 if the param nport is incorrect.
 *  Otherwise return 0.
 */
int get_port_dir_bit (uint8_t nport, bool* value, uint8_t pos)
{
	if(nport < 8 && pos < 8)
	{
		get_bit(*portd[nport], value, pos);
		return 0;
	}
	return -1;
}

/**
 * Set direction of HW Port.
 * \param nport The HW port to set. The value must be betwen 0 and 7.
 * \param value The value of direction to set.
 * \return The value returned is -1 if the param nport is incorrect.
 *  Otherwise return 0.
 */
int set_port_dir(uint8_t nport, uint8_t value)
{
	if(nport < 8)
	{
		*portd[nport] = value;
		return 0;
	}
	return -1;
}

/**
 * Get direction of HW Port.
 * \param nport The HW port to get. The value must be betwen 0 and 7.
 * \param value The pointer to the return value.
 * \return The value returned is -1 if the param nport is incorrect.
 *  Otherwise return 0.
 */
int get_port_dir(uint8_t nport, uint8_t* value)
{
	if(nport < 8)
	{
		*value = *portd[nport];
		return 0;
	}
	return -1;
}

/**
 * Set value of HW Port.
 * \param nport The HW port to set. The value must be betwen 0 and 7.
 * \param value The value to set.
 * \return The value returned is -1 if the param nport is incorrect.
 *  Otherwise return 0.
 */
int set_port (uint8_t nport, uint8_t value)
{
	if(nport < 8)
	{
		*port[nport] = value;
		return 0;
	}
	return -1;
}

/**
 * Get value of HW Port.
 * \param nport The HW port to get. The value must be betwen 0 and 7.
 * \param value The pointer to the return value.
 * \return The value returned is -1 if the param nport is incorrect.
 *  Otherwise return 0.
 */
int get_port (uint8_t nport, uint8_t* value)
{
	if(nport < 8)
	{
		*value = *port[nport];
		return 0;
	}
	return -1;
}

/**
 * Do intial setting to use HW port.
 * \return The /dev/mem file descriptor.
 */
int init_ports()
{
	int devmem = open("/dev/mem", O_RDWR|O_SYNC);
	assert(devmem != -1);

	data_page = (unsigned long)mmap(0, getpagesize(), PROT_READ|PROT_WRITE,
		MAP_SHARED, devmem, DATA_PAGE);
	assert (&data_page != MAP_FAILED);

	syscon_page = (unsigned long)mmap(0, getpagesize(), PROT_READ|PROT_WRITE
		, MAP_SHARED, devmem, SYSCON_PAGE);
	assert(&syscon_page != MAP_FAILED);

	uint32_t* deviceCfg = (uint32_t*) (syscon_page + DEVICECFG);
	uint32_t* syscon_unlock = (uint32_t*) (syscon_page + SYSCON_UNLOCK);

	*syscon_unlock = UNLOCK_VAL;
	// TonG = 1  HonIDE = 1 GonIDE = 1 EonIDE = 1
	*deviceCfg |= 0x08000D00;

	port[0] = (uint8_t*) (data_page + PADR);
	port[1] = (uint8_t*) (data_page + PBDR);
	port[2] = (uint8_t*) (data_page + PCDR);
	port[3] = (uint8_t*) (data_page + PDDR);
	port[4] = (uint8_t*) (data_page + PEDR);
	port[5] = (uint8_t*) (data_page + PFDR);
	port[6] = (uint8_t*) (data_page + PGDR);
	port[7] = (uint8_t*) (data_page + PHDR);

	portd[0] = (uint8_t*) (data_page + PADDR);
	portd[1] = (uint8_t*) (data_page + PBDDR);
	portd[2] = (uint8_t*) (data_page + PCDDR);
	portd[3] = (uint8_t*) (data_page + PDDDR);
	portd[4] = (uint8_t*) (data_page + PEDDR);
	portd[5] = (uint8_t*) (data_page + PFDDR);
	portd[6] = (uint8_t*) (data_page + PGDDR);
	portd[7] = (uint8_t*) (data_page + PHDDR);

    return devmem;
}

/**
 * Close /dev/mem.
 * \param devmem The /dev/mem file descriptor.
 */
void close_ports(int devmem)
{
	close(devmem);
}

inline void set_bit(bool src, volatile uint8_t *dst, uint8_t bit)
{
	int value = 1 << bit;
	if(src)
		*dst |= value;
	else
		*dst &= ~value;
}

inline void get_bit(volatile uint8_t src, bool *dst, uint8_t bit)
{
	int value = 1 << bit;
	*dst = (src & value) >> bit;
}