HackRF-Treasure-Chest/Software/portapack-mayhem/hackrf/firmware/libopencm3/lib/lpc43xx/i2c.c

/** @defgroup i2c_file I2C

@ingroup LPC43xx

@brief <b>libopencm3 LPC43xx I2C</b>

@version 1.0.0

@author @htmlonly &copy; @endhtmlonly 2012 Michael Ossmann <mike@ossmann.com>
@author @htmlonly &copy; @endhtmlonly 2014 Jared Boone <jared@sharebrained.com>

LGPL License Terms @ref lgpl_license
*/

/*
 * This file is part of the libopencm3 project.
 *
 * Copyright (C) 2012 Michael Ossmann <mike@ossmann.com>
 * Copyright (C) 2014 Benjamin Vernoux <bvernoux@gmail.com>
 * Copyright (C) 2014 Jared Boone <jared@sharebrained.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/>.
 */

/*
 * This is a very minimal I2C driver just to make sure we can get the
 * peripheral working.
 */

/**@{*/

#include <libopencm3/lpc43xx/i2c.h>
#include <libopencm3/lpc43xx/scu.h>
#include <libopencm3/lpc43xx/cgu.h>

#define I2C_TIMEOUT (10000)

#define SFSP_I2C1_SDA_SCL (0x00000001 | SCU_CONF_ZIF_DIS_IN_GLITCH_FILT | SCU_CONF_EZI_EN_IN_BUFFER)

void i2c_init(i2c_port_t port, const uint16_t duty_cycle_count)
{
	I2C_SCLH(port) = duty_cycle_count;
	I2C_SCLL(port) = duty_cycle_count;

	/* clear the control bits */
	I2C_CONCLR(port) = (I2C_CONCLR_AAC | I2C_CONCLR_SIC
			| I2C_CONCLR_STAC | I2C_CONCLR_I2ENC);

	/* enable I2C0 */
	I2C_CONSET(port) = I2C_CONSET_I2EN;
}

void i2c_disable(i2c_port_t port) {
	I2C_CONCLR(port) = I2C_CONCLR_I2ENC;
}

/* transmit start bit */
void i2c_tx_start(i2c_port_t port)
{
	uint32_t timeout;

	I2C_CONCLR(port) = I2C_CONCLR_SIC;
	I2C_CONSET(port) = I2C_CONSET_STA;

	timeout = 0;
	while( (!(I2C_CONSET(port) & I2C_CONSET_SI)) && (timeout < I2C_TIMEOUT) )
	{
		timeout++;
	}

	I2C_CONCLR(port) = I2C_CONCLR_STAC;
}

/* transmit data byte */
void i2c_tx_byte(i2c_port_t port, uint8_t byte)
{
	uint32_t timeout;

	if (I2C_CONSET(port) & I2C_CONSET_STA) {
		I2C_CONCLR(port) = I2C_CONCLR_STAC;
	}
	I2C_DAT(port) = byte;
	I2C_CONCLR(port) = I2C_CONCLR_SIC;

	timeout = 0;
	while( (!(I2C_CONSET(port) & I2C_CONSET_SI)) && (timeout < I2C_TIMEOUT) )
	{
		timeout++;
	}
}

/* receive data byte */
uint8_t i2c_rx_byte(i2c_port_t port, bool ack)
{
	uint32_t timeout;

	if (I2C_CONSET(port) & I2C_CONSET_STA) {
		I2C_CONCLR(port) = I2C_CONCLR_STAC;
	}
	I2C_CONCLR(port) = I2C_CONCLR_SIC;

	if (ack) {
		I2C_CONSET(port) = I2C_CONSET_AA;
	} else {
		I2C_CONCLR(port) = I2C_CONCLR_AAC;
	}

	timeout = 0;
	while( (!(I2C_CONSET(port) & I2C_CONSET_SI)) && (timeout < I2C_TIMEOUT) )
	{
		timeout++;
	}

	return I2C_DAT(port);
}

/* transmit stop bit */
void i2c_stop(i2c_port_t port)
{
	if (I2C_CONSET(port) & I2C_CONSET_STA) {
		I2C_CONCLR(port) = I2C_CONCLR_STAC;
	}
	I2C_CONSET(port) = I2C_CONSET_STO;
	I2C_CONCLR(port) = I2C_CONCLR_SIC;
}

/* I2C0 wrappers for compatibility with old code */
void i2c0_init(const uint16_t duty_cycle_count)
{
	/* enable input on SCL and SDA pins */
	SCU_SFSI2C0 = SCU_I2C0_NOMINAL;

	i2c_init(I2C0, duty_cycle_count);
}

void i2c1_init(const uint16_t duty_cycle_count)
{
	/* Configure pin function for I2C1*/
	SCU_SFSP2_3 = SFSP_I2C1_SDA_SCL;
	SCU_SFSP2_4 = SFSP_I2C1_SDA_SCL;

	i2c_init(I2C1, duty_cycle_count);
}

/* transmit start bit */
void i2c0_tx_start(void)
{
	i2c_tx_start(I2C0);
}

/* transmit start bit */
void i2c1_tx_start(void)
{
	i2c_tx_start(I2C1);
}

/* transmit data byte */
void i2c0_tx_byte(uint8_t byte)
{
	i2c_tx_byte(I2C0, byte);
}

/* transmit data byte */
void i2c1_tx_byte(uint8_t byte)
{
	i2c_tx_byte(I2C1, byte);
}

/* receive data byte */
uint8_t i2c0_rx_byte(bool ack) {
	return i2c_rx_byte(I2C0, ack);
}

/* receive data byte */
uint8_t i2c1_rx_byte(bool ack) {
	return i2c_rx_byte(I2C1, ack);
}

/* transmit stop bit */
void i2c0_stop(void)
{
	i2c_stop(I2C0);
}

/* transmit stop bit */
void i2c1_stop(void)
{
	i2c_stop(I2C1);
}

/**@}*/