88 lines
1.5 KiB
C
88 lines
1.5 KiB
C
/*
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* pcf8574.c
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* PCF8574 IO expander helper functions using libsoc API.
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*
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* libsoc i2c API Documentation: http://jackmitch.github.io/libsoc/c/i2c/#i2c
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*
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* Copyright (C) 2017 - BhuvanChandra DV <bhuvanchandradv@gmail.com>
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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#include "pcf8574.h"
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i2c* pcf8574_init(uint8_t i2c_bus, uint8_t i2c_address)
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{
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i2c *i2c = libsoc_i2c_init(i2c_bus, i2c_address);
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if (i2c == NULL) {
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perror("libsoc_i2c_init failed");
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return i2c;
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}
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return i2c;
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}
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int pcf8574_free(i2c *i2c)
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{
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return libsoc_i2c_free(i2c);
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}
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uint8_t pcf8574_port_read(i2c *i2c)
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{
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uint8_t res;
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if (libsoc_i2c_read(i2c, &res, 1))
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return 0;
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return res;
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}
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size_t pcf8574_port_read_buf(i2c *i2c, void *buf, size_t len)
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{
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uint8_t *_buf = (uint8_t *)buf;
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if (!len || !buf)
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return 0;
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if (libsoc_i2c_read(i2c, _buf, len))
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return 0;
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return len;
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}
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size_t pcf8574_port_write_buf(i2c *i2c, void *buf, size_t len)
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{
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uint8_t *_buf = (uint8_t *)buf;
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if (!len || !buf)
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return 0;
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if (libsoc_i2c_write(i2c, _buf, len))
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return 0;
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return len;
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}
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void pcf8574_port_write(i2c *i2c, uint8_t value)
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{
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libsoc_i2c_write(i2c, &value, 1);
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}
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bool pcf8574_gpio_read(i2c *i2c, uint8_t num)
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{
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return (bool)((pcf8574_port_read(i2c) >> num) & 1);
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}
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void pcf8574_gpio_write(i2c *i2c, uint8_t num, bool value)
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{
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uint8_t bit = (uint8_t)!value << num;
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uint8_t mask = ~(1 << num);
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pcf8574_port_write (i2c, (pcf8574_port_read(i2c) & mask) | bit);
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}
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