/*
 * Copyright 2016 Dominic Spill <dominicgs@gmail.com>
 *
 * This file is part of HackRF.
 *
 * 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 2, 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; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#include "operacake.h"
#include "hackrf_core.h"

#define OPERACAKE_PIN_OE(x)      (x<<7)
#define OPERACAKE_PIN_U2CTRL1(x) (x<<6)
#define OPERACAKE_PIN_U2CTRL0(x) (x<<5)
#define OPERACAKE_PIN_U3CTRL1(x) (x<<4)
#define OPERACAKE_PIN_U3CTRL0(x) (x<<3)
#define OPERACAKE_PIN_U1CTRL(x)  (x<<2)
#define OPERACAKE_PIN_LEDEN2(x)  (x<<1)
#define OPERACAKE_PIN_LEDEN(x)   (x<<0)

#define OPERACAKE_PORT_A1 (OPERACAKE_PIN_U2CTRL0(0) | OPERACAKE_PIN_U2CTRL1(0))
#define OPERACAKE_PORT_A2 (OPERACAKE_PIN_U2CTRL0(1) | OPERACAKE_PIN_U2CTRL1(0))
#define OPERACAKE_PORT_A3 (OPERACAKE_PIN_U2CTRL0(0) | OPERACAKE_PIN_U2CTRL1(1))
#define OPERACAKE_PORT_A4 (OPERACAKE_PIN_U2CTRL0(1) | OPERACAKE_PIN_U2CTRL1(1))

#define OPERACAKE_PORT_B1 (OPERACAKE_PIN_U3CTRL0(0) | OPERACAKE_PIN_U3CTRL1(0))
#define OPERACAKE_PORT_B2 (OPERACAKE_PIN_U3CTRL0(1) | OPERACAKE_PIN_U3CTRL1(0))
#define OPERACAKE_PORT_B3 (OPERACAKE_PIN_U3CTRL0(0) | OPERACAKE_PIN_U3CTRL1(1))
#define OPERACAKE_PORT_B4 (OPERACAKE_PIN_U3CTRL0(1) | OPERACAKE_PIN_U3CTRL1(1))

#define OPERACAKE_SAMESIDE  OPERACAKE_PIN_U1CTRL(1)
#define OPERACAKE_CROSSOVER OPERACAKE_PIN_U1CTRL(0)
#define OPERACAKE_EN_LEDS (OPERACAKE_PIN_LEDEN2(1) | OPERACAKE_PIN_LEDEN2(0))
#define OPERACAKE_GPIO_EN OPERACAKE_PIN_OE(0)
#define OPERACAKE_GPIO_DISABLE OPERACAKE_PIN_OE(1)

#define OPERACAKE_REG_INPUT    0x00
#define OPERACAKE_REG_OUTPUT   0x01
#define OPERACAKE_REG_POLARITY 0x02
#define OPERACAKE_REG_CONFIG   0x03

#define OPERACAKE_DEFAULT_OUTPUT (OPERACAKE_GPIO_DISABLE | OPERACAKE_SAMESIDE \
								  | OPERACAKE_PORT_A1 | OPERACAKE_PORT_B1 \
								  | OPERACAKE_EN_LEDS)
#define OPERACAKE_CONFIG_ALL_OUTPUT (0x00)

typedef struct {
	i2c_bus_t* const bus;
	uint8_t i2c_address;
} operacake_driver_t;

operacake_driver_t operacake_driver = {
	.bus = &i2c0,
	.i2c_address = 0x18,
};

uint8_t operacake_read_single(operacake_driver_t* drv, uint8_t reg);
void operacake_write(operacake_driver_t* drv, const uint8_t* const data, const size_t data_count);


uint8_t operacake_init(void) {
	/* TODO: detect Operacake */
	uint8_t output_data[] = {OPERACAKE_REG_OUTPUT,
							 OPERACAKE_DEFAULT_OUTPUT};
	operacake_write(&operacake_driver, output_data, 2);
	const uint8_t config_data[] = {OPERACAKE_REG_CONFIG,
								   OPERACAKE_CONFIG_ALL_OUTPUT};
	operacake_write(&operacake_driver, config_data, 2);
	return 0;
}

uint8_t port_to_pins(uint8_t port) {
	switch(port) {
		case OPERACAKE_PA1:
			return OPERACAKE_PORT_A1;
		case OPERACAKE_PA2:
			return OPERACAKE_PORT_A2;
		case OPERACAKE_PA3:
			return OPERACAKE_PORT_A3;
		case OPERACAKE_PA4:
			return OPERACAKE_PORT_A4;

		case OPERACAKE_PB1:
			return OPERACAKE_PORT_B1;
		case OPERACAKE_PB2:
			return OPERACAKE_PORT_B2;
		case OPERACAKE_PB3:
			return OPERACAKE_PORT_B3;
		case OPERACAKE_PB4:
			return OPERACAKE_PORT_B4;
	}
	return 0xFF;
}

uint8_t operacake_set_ports(uint8_t PA, uint8_t PB) {
	uint8_t side, pa, pb;
	uint8_t output_data[2];
	/* Start with some error checking,
	 * which should have been done either
	 * on the host or elsewhere in firmware
	 */
	if((PA > OPERACAKE_PB4) || (PB > OPERACAKE_PB4)) {
		return 1;
	}
	/* Check which side PA and PB are on */
	if(((PA <= OPERACAKE_PA4) && (PB <= OPERACAKE_PA4))
	    || ((PA > OPERACAKE_PA4) && (PB > OPERACAKE_PA4))) {
		return 1;
	}
	
	if(PA > OPERACAKE_PA4)
		side = OPERACAKE_CROSSOVER;
	else
		side = OPERACAKE_SAMESIDE;

		pa = port_to_pins(PA);
		pb = port_to_pins(PB);
		
	output_data[0] = OPERACAKE_REG_OUTPUT;
	output_data[1] = (OPERACAKE_GPIO_DISABLE | side
					| pa | pb | OPERACAKE_EN_LEDS);
	operacake_write(&operacake_driver, output_data, 2);
	return 0;
}

/* Write to one of the PCA9557 registers */
void operacake_write(operacake_driver_t* drv, const uint8_t* const data, const size_t data_count) {
	i2c_bus_transfer(drv->bus, drv->i2c_address, data, data_count, NULL, 0);
}