112 lines
2.5 KiB
C
112 lines
2.5 KiB
C
/** @defgroup i2c_file I2C
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@ingroup LPC43xx
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@brief <b>libopencm3 LPC43xx I2C</b>
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@version 1.0.0
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@author @htmlonly © @endhtmlonly 2012 Michael Ossmann <mike@ossmann.com>
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LGPL License Terms @ref lgpl_license
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*/
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/*
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* This file is part of the libopencm3 project.
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*
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* Copyright (C) 2012 Michael Ossmann <mike@ossmann.com>
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*
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* This library is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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* This is a very minimal I2C driver just to make sure we can get the
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* peripheral working.
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*/
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/**@{*/
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#include <libopencm3/lpc43xx/i2c.h>
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#include <libopencm3/lpc43xx/scu.h>
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#include <libopencm3/lpc43xx/cgu.h>
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void i2c0_init(void)
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{
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/* enable input on SCL and SDA pins */
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SCU_SFSI2C0 = SCU_I2C0_NOMINAL;
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/* use IRC as clock source for APB1 (including I2C0) */
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CGU_BASE_APB1_CLK = (CGU_SRC_IRC << CGU_BASE_CLK_SEL_SHIFT);
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/* FIXME assuming we're on IRC at 12 MHz */
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/* 400 kHz I2C */
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I2C0_SCLH = 15;
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I2C0_SCLL = 15;
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/* 100 kHz I2C */
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/*
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I2C0_SCLH = 60;
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I2C0_SCLL = 60;
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*/
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/* clear the control bits */
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I2C0_CONCLR = (I2C_CONCLR_AAC | I2C_CONCLR_SIC
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| I2C_CONCLR_STAC | I2C_CONCLR_I2ENC);
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/* enable I2C0 */
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I2C0_CONSET = I2C_CONSET_I2EN;
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}
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/* transmit start bit */
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void i2c0_tx_start(void)
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{
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I2C0_CONCLR = I2C_CONCLR_SIC;
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I2C0_CONSET = I2C_CONSET_STA;
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while (!(I2C0_CONSET & I2C_CONSET_SI));
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I2C0_CONCLR = I2C_CONCLR_STAC;
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}
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/* transmit data byte */
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void i2c0_tx_byte(u8 byte)
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{
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if (I2C0_CONSET & I2C_CONSET_STA)
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I2C0_CONCLR = I2C_CONCLR_STAC;
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I2C0_DAT = byte;
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I2C0_CONCLR = I2C_CONCLR_SIC;
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while (!(I2C0_CONSET & I2C_CONSET_SI));
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}
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/* receive data byte */
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u8 i2c0_rx_byte(void)
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{
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if (I2C0_CONSET & I2C_CONSET_STA)
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I2C0_CONCLR = I2C_CONCLR_STAC;
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I2C0_CONCLR = I2C_CONCLR_SIC;
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while (!(I2C0_CONSET & I2C_CONSET_SI));
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return I2C0_DAT;
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}
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/* transmit stop bit */
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void i2c0_stop(void)
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{
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if (I2C0_CONSET & I2C_CONSET_STA)
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I2C0_CONCLR = I2C_CONCLR_STAC;
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I2C0_CONSET = I2C_CONSET_STO;
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I2C0_CONCLR = I2C_CONCLR_SIC;
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}
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/**@}*/
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