97 lines
2.7 KiB
C
97 lines
2.7 KiB
C
/**
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* \file
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* <!--
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* This file is part of BeRTOS.
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*
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* Bertos is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program 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 General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* As a special exception, you may use this file as part of a free software
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* library without restriction. Specifically, if other files instantiate
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* templates or use macros or inline functions from this file, or you compile
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* this file and link it with other files to produce an executable, this
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* file does not by itself cause the resulting executable to be covered by
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* the GNU General Public License. This exception does not however
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* invalidate any other reasons why the executable file might be covered by
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* the GNU General Public License.
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*
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* Copyright 2007 Develer S.r.l. (http://www.develer.com/)
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*
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* -->
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*
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* \brief PCF8574 i2c port expander driver.
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*
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* This driver controls the PCF8574.
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* The PCF8574 is an 8bit i2c port expander.
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* You can read/write 8 pins through an i2c bus.
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* The pins are quasi-bidirectionals, this mean that
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* without the need of a direction register you can use
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* each pin as input or output, see datasheet on how this
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* is achieved.
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*
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* \author Francesco Sacchi <batt@develer.com>
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*/
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#include "pcf8574.h"
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#include "cfg/cfg_i2c.h"
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#include <cfg/module.h>
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#include <drv/i2c.h>
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/**
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* Read PCF8574 \a pcf bit status.
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* \return the pins status or EOF on errors.
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*/
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int pcf8574_get_2(I2c *i2c, Pcf8574 *pcf)
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{
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i2c_start_r(i2c, PCF8574ID | ((pcf->addr << 1) & 0xF7), 1, I2C_STOP);
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int data = i2c_getc(i2c);
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if (i2c_error(i2c))
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data = EOF;
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return data;
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}
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/**
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* Write to PCF8574 \a pcf port \a data.
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* \return true if ok, false on errors.
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*/
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bool pcf8574_put_3(I2c *i2c, Pcf8574 *pcf, uint8_t data)
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{
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i2c_start_w(i2c, PCF8574ID | ((pcf->addr << 1) & 0xF7), 1, I2C_STOP);
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i2c_putc(i2c, data);
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if (i2c_error(i2c))
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return false;
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return true;
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}
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/**
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* Init a PCF8574 on the bus with addr \a addr.
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* \return true if device is found, false otherwise.
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*/
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bool pcf8574_init_3(I2c *i2c, Pcf8574 *pcf, pcf8574_addr addr)
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{
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ASSERT(i2c);
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pcf->addr = addr;
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return (pcf8574_get(i2c, pcf) != EOF);
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}
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