/*
 * This file is part of the libopencm3 project.
 *
 * Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
 * Copyright (C) 2011 Stephen Caudle <scaudle@doceme.com>
 * Modified by Fernando Cortes <fermando.corcam@gmail.com>
 * modified by Guillermo Rivera <memogrg@gmail.com>
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <errno.h>
#include <stdio.h>
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/usart.h>
#include <libopencm3/stm32/i2c.h>
#include <libopencm3/stm32/gpio.h>

#define LBLUE GPIOE, GPIO8
#define LRED GPIOE, GPIO9
#define LORANGE GPIOE, GPIO10
#define LGREEN GPIOE, GPIO11
#define LBLUE2 GPIOE, GPIO12
#define LRED2 GPIOE, GPIO13
#define LORANGE2 GPIOE, GPIO14
#define LGREEN2 GPIOE, GPIO15

#define LD4 GPIOE, GPIO8
#define LD3 GPIOE, GPIO9
#define LD5 GPIOE, GPIO10
#define LD7 GPIOE, GPIO11
#define LD9 GPIOE, GPIO12
#define LD10 GPIOE, GPIO13
#define LD8 GPIOE, GPIO14
#define LD6 GPIOE, GPIO15

int _write(int file, char *ptr, int len);

static void i2c_setup(void)
{
	rcc_periph_clock_enable(RCC_I2C1);
	rcc_periph_clock_enable(RCC_GPIOB);
	rcc_set_i2c_clock_hsi(I2C1);

	i2c_reset(I2C1);
	/* Setup GPIO pin GPIO_USART2_TX/GPIO9 on GPIO port A for transmit. */
	gpio_mode_setup(GPIOB, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO6 | GPIO7);
	gpio_set_af(GPIOB, GPIO_AF4, GPIO6 | GPIO7);
	i2c_peripheral_disable(I2C1);
	//configure ANFOFF DNF[3:0] in CR1
	i2c_enable_analog_filter(I2C1);
	i2c_set_digital_filter(I2C1, 0);
	/* HSI is at 8Mhz */
	i2c_set_speed(I2C1, i2c_speed_sm_100k, 8);
	//configure No-Stretch CR1 (only relevant in slave mode)
	i2c_enable_stretching(I2C1);
	//addressing mode
	i2c_set_7bit_addr_mode(I2C1);
	i2c_peripheral_enable(I2C1);
}

static void usart_setup(void)
{
	/* Enable clocks for GPIO port A (for GPIO_USART2_TX) and USART2. */
	rcc_periph_clock_enable(RCC_USART2);
	rcc_periph_clock_enable(RCC_GPIOA);

	/* Setup GPIO pin GPIO_USART2_TX/GPIO9 on GPIO port A for transmit. */
	gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO2 | GPIO3);
	gpio_set_af(GPIOA, GPIO_AF7, GPIO2| GPIO3);

	/* Setup UART parameters. */
	usart_set_baudrate(USART2, 115200);
	usart_set_databits(USART2, 8);
	usart_set_stopbits(USART2, USART_STOPBITS_1);
	usart_set_mode(USART2, USART_MODE_TX_RX);
	usart_set_parity(USART2, USART_PARITY_NONE);
	usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);

	/* Finally enable the USART. */
	usart_enable(USART2);
}

static void gpio_setup(void)
{
	rcc_periph_clock_enable(RCC_GPIOE);
	gpio_mode_setup(GPIOE, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE,
		GPIO8 | GPIO9 | GPIO10 | GPIO11 | GPIO12 | GPIO13 |
		GPIO14 | GPIO15);
}

int _write(int file, char *ptr, int len)
{
        int i;

        if (file == 1) {
                for (i = 0; i < len; i++) {
			if (ptr[i] == '\n') {
				usart_send_blocking(USART2, '\r');
			}
                        usart_send_blocking(USART2, ptr[i]);
		}
                return i;
        }
        errno = EIO;
        return -1;
}


static void clock_setup(void)
{
	rcc_clock_setup_hsi(&rcc_hsi_configs[RCC_CLOCK_HSI_64MHZ]);
}

#define I2C_ACC_ADDR 0x19
#define I2C_MAG_ADDR 0x1E
#define ACC_STATUS 0x27
#define ACC_CTRL_REG1_A 0x20
#define ACC_CTRL_REG1_A_ODR_SHIFT 4
#define ACC_CTRL_REG1_A_ODR_MASK 0xF
#define ACC_CTRL_REG1_A_XEN (1 << 0)
#define ACC_CTRL_REG4_A 0x23

#define ACC_OUT_X_L_A 0x28
#define ACC_OUT_X_H_A 0x29

int main(void)
{
	clock_setup();
	gpio_setup();
	usart_setup();
	printf("Hello, we're running\n");
	i2c_setup();
	uint8_t cmd = ACC_CTRL_REG1_A;
	uint8_t data;
	i2c_transfer7(I2C1, I2C_ACC_ADDR, &cmd, 1, &data, 1);
	cmd = ACC_CTRL_REG4_A;
	i2c_transfer7(I2C1, I2C_ACC_ADDR, &cmd, 1, &data, 1);
	int16_t acc_x;

	while (1) {

		cmd = ACC_STATUS;
		i2c_transfer7(I2C1, I2C_ACC_ADDR, &cmd, 1, &data, 1);
		cmd = ACC_OUT_X_L_A;
		i2c_transfer7(I2C1, I2C_ACC_ADDR, &cmd, 1, &data, 1);
		acc_x = data;
		cmd = ACC_OUT_X_H_A;
		i2c_transfer7(I2C1, I2C_ACC_ADDR, &cmd, 1, &data, 1);
		acc_x |= ((uint16_t)data << 8);
		printf("data was %d\n", acc_x);
	}

	return 0;
}